[OpenWrt-Devel] [PATCH 2/3] kernel: backport v5.8 i2c-pxa updates
Russell King
linux at armlinux.org.uk
Thu May 21 04:57:27 EDT 2020
Add i2c-pxa updates queued for v5.8, which add bus recovery to this
driver; this is needed for the uDPU platform.
Signed-off-by: Russell King <linux at armlinux.org.uk>
---
...pxa-use-official-address-byte-helper.patch | 64 +++
...5.8-i2c-pxa-remove-unneeded-includes.patch | 42 ++
...ge-includes-to-be-in-alphabetical-or.patch | 57 +++
...-re-arrange-functions-to-flow-better.patch | 385 ++++++++++++++++++
...e-arrange-register-field-definitions.patch | 166 ++++++++
...nd-use-definitions-for-IBMR-register.patch | 71 ++++
...-set-fm-and-hs-members-for-each-type.patch | 71 ++++
...ove-private-definitions-to-i2c-pxa.c.patch | 135 ++++++
...-move-DT-IDs-along-side-platform-IDs.patch | 55 +++
..._pxa_scream_blue_murder-debug-output.patch | 52 +++
...13-v5.8-i2c-pxa-clean-up-decode_bits.patch | 58 +++
...pxa_wait_bus_not_busy-boundary-condi.patch | 58 +++
...lidate-i2c_pxa_-xfer-implementations.patch | 96 +++++
...omplaints-with-non-responsive-slaves.patch | 72 ++++
...a-ensure-timeout-messages-are-unique.patch | 50 +++
...2c-pxa-remove-some-unnecessary-debug.patch | 39 ++
...l-master-action-bits-in-i2c_pxa_stop.patch | 43 ++
...a-use-master-abort-for-device-probes.patch | 40 ++
...a-implement-generic-i2c-bus-recovery.patch | 290 +++++++++++++
19 files changed, 1844 insertions(+)
create mode 100644 target/linux/generic/backport-5.4/803-v5.8-i2c-pxa-use-official-address-byte-helper.patch
create mode 100644 target/linux/generic/backport-5.4/804-v5.8-i2c-pxa-remove-unneeded-includes.patch
create mode 100644 target/linux/generic/backport-5.4/805-v5.8-i2c-pxa-re-arrange-includes-to-be-in-alphabetical-or.patch
create mode 100644 target/linux/generic/backport-5.4/806-v5.8-i2c-pxa-re-arrange-functions-to-flow-better.patch
create mode 100644 target/linux/generic/backport-5.4/807-v5.8-i2c-pxa-re-arrange-register-field-definitions.patch
create mode 100644 target/linux/generic/backport-5.4/808-v5.8-i2c-pxa-add-and-use-definitions-for-IBMR-register.patch
create mode 100644 target/linux/generic/backport-5.4/809-v5.8-i2c-pxa-always-set-fm-and-hs-members-for-each-type.patch
create mode 100644 target/linux/generic/backport-5.4/810-v5.8-i2c-pxa-move-private-definitions-to-i2c-pxa.c.patch
create mode 100644 target/linux/generic/backport-5.4/811-v5.8-i2c-pxa-move-DT-IDs-along-side-platform-IDs.patch
create mode 100644 target/linux/generic/backport-5.4/812-v5.8-i2c-pxa-fix-i2c_pxa_scream_blue_murder-debug-output.patch
create mode 100644 target/linux/generic/backport-5.4/813-v5.8-i2c-pxa-clean-up-decode_bits.patch
create mode 100644 target/linux/generic/backport-5.4/814-v5.8-i2c-pxa-fix-i2c_pxa_wait_bus_not_busy-boundary-condi.patch
create mode 100644 target/linux/generic/backport-5.4/815-v5.8-i2c-pxa-consolidate-i2c_pxa_-xfer-implementations.patch
create mode 100644 target/linux/generic/backport-5.4/816-v5.8-i2c-pxa-avoid-complaints-with-non-responsive-slaves.patch
create mode 100644 target/linux/generic/backport-5.4/817-v5.8-i2c-pxa-ensure-timeout-messages-are-unique.patch
create mode 100644 target/linux/generic/backport-5.4/818-v5.8-i2c-pxa-remove-some-unnecessary-debug.patch
create mode 100644 target/linux/generic/backport-5.4/819-v5.8-i2c-pxa-clear-all-master-action-bits-in-i2c_pxa_stop.patch
create mode 100644 target/linux/generic/backport-5.4/820-v5.8-i2c-pxa-use-master-abort-for-device-probes.patch
create mode 100644 target/linux/generic/backport-5.4/821-v5.8-i2c-pxa-implement-generic-i2c-bus-recovery.patch
diff --git a/target/linux/generic/backport-5.4/803-v5.8-i2c-pxa-use-official-address-byte-helper.patch b/target/linux/generic/backport-5.4/803-v5.8-i2c-pxa-use-official-address-byte-helper.patch
new file mode 100644
index 000000000000..8aaa6c9b3c1c
--- /dev/null
+++ b/target/linux/generic/backport-5.4/803-v5.8-i2c-pxa-use-official-address-byte-helper.patch
@@ -0,0 +1,64 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Cc: linux-i2c at vger.kernel.org
+Subject: [PATCH 01/17] i2c: pxa: use official address byte helper
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+i2c-pxa was created before i2c_8bit_addr_from_msg() was implemented,
+and used its own i2c_pxa_addr_byte() which is functionally the same.
+Sadly, it was never updated to use this new helper. Switch it over.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 21 +++++++--------------
+ 1 file changed, 7 insertions(+), 14 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index 2c3c3d6935c0..966000923e8e 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -675,16 +675,6 @@ static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
+ * PXA I2C Master mode
+ */
+
+-static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
+-{
+- unsigned int addr = (msg->addr & 0x7f) << 1;
+-
+- if (msg->flags & I2C_M_RD)
+- addr |= 1;
+-
+- return addr;
+-}
+-
+ static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
+ {
+ u32 icr;
+@@ -693,8 +683,8 @@ static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
+ /*
+ * Step 1: target slave address into IDBR
+ */
+- writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
+- i2c->req_slave_addr = i2c_pxa_addr_byte(i2c->msg);
++ i2c->req_slave_addr = i2c_8bit_addr_from_msg(i2c->msg);
++ writel(i2c->req_slave_addr, _IDBR(i2c));
+
+ /*
+ * Step 2: initiate the write.
+@@ -1006,8 +999,8 @@ static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
+ /*
+ * Write the next address.
+ */
+- writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
+- i2c->req_slave_addr = i2c_pxa_addr_byte(i2c->msg);
++ i2c->req_slave_addr = i2c_8bit_addr_from_msg(i2c->msg);
++ writel(i2c->req_slave_addr, _IDBR(i2c));
+
+ /*
+ * And trigger a repeated start, and send the byte.
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/804-v5.8-i2c-pxa-remove-unneeded-includes.patch b/target/linux/generic/backport-5.4/804-v5.8-i2c-pxa-remove-unneeded-includes.patch
new file mode 100644
index 000000000000..ed4a3d592877
--- /dev/null
+++ b/target/linux/generic/backport-5.4/804-v5.8-i2c-pxa-remove-unneeded-includes.patch
@@ -0,0 +1,42 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Cc: linux-i2c at vger.kernel.org
+Subject: [PATCH 02/17] i2c: pxa: remove unneeded includes
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+i2c-pxa does not need linux/sched.h nor linux/time.h includes, so
+remove these.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 4 ----
+ 1 file changed, 4 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index 966000923e8e..eddb749c9eae 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -20,8 +20,6 @@
+ #include <linux/module.h>
+ #include <linux/i2c.h>
+ #include <linux/init.h>
+-#include <linux/time.h>
+-#include <linux/sched.h>
+ #include <linux/delay.h>
+ #include <linux/errno.h>
+ #include <linux/interrupt.h>
+@@ -35,8 +33,6 @@
+ #include <linux/io.h>
+ #include <linux/platform_data/i2c-pxa.h>
+
+-#include <asm/irq.h>
+-
+ struct pxa_reg_layout {
+ u32 ibmr;
+ u32 idbr;
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/805-v5.8-i2c-pxa-re-arrange-includes-to-be-in-alphabetical-or.patch b/target/linux/generic/backport-5.4/805-v5.8-i2c-pxa-re-arrange-includes-to-be-in-alphabetical-or.patch
new file mode 100644
index 000000000000..ccca8d1dc7b4
--- /dev/null
+++ b/target/linux/generic/backport-5.4/805-v5.8-i2c-pxa-re-arrange-includes-to-be-in-alphabetical-or.patch
@@ -0,0 +1,57 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Cc: linux-i2c at vger.kernel.org
+Subject: [PATCH 03/17] i2c: pxa: re-arrange includes to be in alphabetical
+ order
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Arrange the includes to be in alphabetical order to help avoid
+duplicated includes.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 18 +++++++++---------
+ 1 file changed, 9 insertions(+), 9 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index eddb749c9eae..ee83d2e46de0 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -16,22 +16,22 @@
+ * Dec 2004: Added support for PXA27x and slave device probing [Liam Girdwood]
+ * Feb 2005: Rework slave mode handling [RMK]
+ */
+-#include <linux/kernel.h>
+-#include <linux/module.h>
+-#include <linux/i2c.h>
+-#include <linux/init.h>
++#include <linux/clk.h>
+ #include <linux/delay.h>
++#include <linux/err.h>
+ #include <linux/errno.h>
+-#include <linux/interrupt.h>
++#include <linux/i2c.h>
+ #include <linux/i2c-pxa.h>
++#include <linux/init.h>
++#include <linux/interrupt.h>
++#include <linux/io.h>
++#include <linux/kernel.h>
++#include <linux/module.h>
+ #include <linux/of.h>
+ #include <linux/of_device.h>
+ #include <linux/platform_device.h>
+-#include <linux/err.h>
+-#include <linux/clk.h>
+-#include <linux/slab.h>
+-#include <linux/io.h>
+ #include <linux/platform_data/i2c-pxa.h>
++#include <linux/slab.h>
+
+ struct pxa_reg_layout {
+ u32 ibmr;
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/806-v5.8-i2c-pxa-re-arrange-functions-to-flow-better.patch b/target/linux/generic/backport-5.4/806-v5.8-i2c-pxa-re-arrange-functions-to-flow-better.patch
new file mode 100644
index 000000000000..efe7071de4f0
--- /dev/null
+++ b/target/linux/generic/backport-5.4/806-v5.8-i2c-pxa-re-arrange-functions-to-flow-better.patch
@@ -0,0 +1,385 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Cc: linux-i2c at vger.kernel.org
+Subject: [PATCH 04/17] i2c: pxa: re-arrange functions to flow better
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Re-arrange the PXA I2C code to avoid forward declarations, and keep
+similar functionality (e.g. the non-IRQ mode support) together. This
+improves code readability.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 325 +++++++++++++++++------------------
+ 1 file changed, 162 insertions(+), 163 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index ee83d2e46de0..e5f00ae39861 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -327,7 +327,6 @@ static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
+ #endif /* ifdef DEBUG / else */
+
+ static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
+-static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
+
+ static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
+ {
+@@ -703,34 +702,6 @@ static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
+ writel(icr, _ICR(i2c));
+ }
+
+-static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
+-{
+- /* make timeout the same as for interrupt based functions */
+- long timeout = 2 * DEF_TIMEOUT;
+-
+- /*
+- * Wait for the bus to become free.
+- */
+- while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
+- udelay(1000);
+- show_state(i2c);
+- }
+-
+- if (timeout < 0) {
+- show_state(i2c);
+- dev_err(&i2c->adap.dev,
+- "i2c_pxa: timeout waiting for bus free\n");
+- return I2C_RETRY;
+- }
+-
+- /*
+- * Set master mode.
+- */
+- writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
+-
+- return 0;
+-}
+-
+ /*
+ * PXA I2C send master code
+ * 1. Load master code to IDBR and send it.
+@@ -759,140 +730,6 @@ static int i2c_pxa_send_mastercode(struct pxa_i2c *i2c)
+ return (timeout == 0) ? I2C_RETRY : 0;
+ }
+
+-static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
+- struct i2c_msg *msg, int num)
+-{
+- unsigned long timeout = 500000; /* 5 seconds */
+- int ret = 0;
+-
+- ret = i2c_pxa_pio_set_master(i2c);
+- if (ret)
+- goto out;
+-
+- i2c->msg = msg;
+- i2c->msg_num = num;
+- i2c->msg_idx = 0;
+- i2c->msg_ptr = 0;
+- i2c->irqlogidx = 0;
+-
+- i2c_pxa_start_message(i2c);
+-
+- while (i2c->msg_num > 0 && --timeout) {
+- i2c_pxa_handler(0, i2c);
+- udelay(10);
+- }
+-
+- i2c_pxa_stop_message(i2c);
+-
+- /*
+- * We place the return code in i2c->msg_idx.
+- */
+- ret = i2c->msg_idx;
+-
+-out:
+- if (timeout == 0) {
+- i2c_pxa_scream_blue_murder(i2c, "timeout");
+- ret = I2C_RETRY;
+- }
+-
+- return ret;
+-}
+-
+-/*
+- * We are protected by the adapter bus mutex.
+- */
+-static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
+-{
+- long timeout;
+- int ret;
+-
+- /*
+- * Wait for the bus to become free.
+- */
+- ret = i2c_pxa_wait_bus_not_busy(i2c);
+- if (ret) {
+- dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
+- goto out;
+- }
+-
+- /*
+- * Set master mode.
+- */
+- ret = i2c_pxa_set_master(i2c);
+- if (ret) {
+- dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
+- goto out;
+- }
+-
+- if (i2c->high_mode) {
+- ret = i2c_pxa_send_mastercode(i2c);
+- if (ret) {
+- dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");
+- goto out;
+- }
+- }
+-
+- spin_lock_irq(&i2c->lock);
+-
+- i2c->msg = msg;
+- i2c->msg_num = num;
+- i2c->msg_idx = 0;
+- i2c->msg_ptr = 0;
+- i2c->irqlogidx = 0;
+-
+- i2c_pxa_start_message(i2c);
+-
+- spin_unlock_irq(&i2c->lock);
+-
+- /*
+- * The rest of the processing occurs in the interrupt handler.
+- */
+- timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
+- i2c_pxa_stop_message(i2c);
+-
+- /*
+- * We place the return code in i2c->msg_idx.
+- */
+- ret = i2c->msg_idx;
+-
+- if (!timeout && i2c->msg_num) {
+- i2c_pxa_scream_blue_murder(i2c, "timeout");
+- ret = I2C_RETRY;
+- }
+-
+- out:
+- return ret;
+-}
+-
+-static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
+- struct i2c_msg msgs[], int num)
+-{
+- struct pxa_i2c *i2c = adap->algo_data;
+- int ret, i;
+-
+- /* If the I2C controller is disabled we need to reset it
+- (probably due to a suspend/resume destroying state). We do
+- this here as we can then avoid worrying about resuming the
+- controller before its users. */
+- if (!(readl(_ICR(i2c)) & ICR_IUE))
+- i2c_pxa_reset(i2c);
+-
+- for (i = adap->retries; i >= 0; i--) {
+- ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
+- if (ret != I2C_RETRY)
+- goto out;
+-
+- if (i2c_debug)
+- dev_dbg(&adap->dev, "Retrying transmission\n");
+- udelay(100);
+- }
+- i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
+- ret = -EREMOTEIO;
+- out:
+- i2c_pxa_set_slave(i2c, ret);
+- return ret;
+-}
+-
+ /*
+ * i2c_pxa_master_complete - complete the message and wake up.
+ */
+@@ -1099,6 +936,71 @@ static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
+ return IRQ_HANDLED;
+ }
+
++/*
++ * We are protected by the adapter bus mutex.
++ */
++static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
++{
++ long timeout;
++ int ret;
++
++ /*
++ * Wait for the bus to become free.
++ */
++ ret = i2c_pxa_wait_bus_not_busy(i2c);
++ if (ret) {
++ dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
++ goto out;
++ }
++
++ /*
++ * Set master mode.
++ */
++ ret = i2c_pxa_set_master(i2c);
++ if (ret) {
++ dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
++ goto out;
++ }
++
++ if (i2c->high_mode) {
++ ret = i2c_pxa_send_mastercode(i2c);
++ if (ret) {
++ dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");
++ goto out;
++ }
++ }
++
++ spin_lock_irq(&i2c->lock);
++
++ i2c->msg = msg;
++ i2c->msg_num = num;
++ i2c->msg_idx = 0;
++ i2c->msg_ptr = 0;
++ i2c->irqlogidx = 0;
++
++ i2c_pxa_start_message(i2c);
++
++ spin_unlock_irq(&i2c->lock);
++
++ /*
++ * The rest of the processing occurs in the interrupt handler.
++ */
++ timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
++ i2c_pxa_stop_message(i2c);
++
++ /*
++ * We place the return code in i2c->msg_idx.
++ */
++ ret = i2c->msg_idx;
++
++ if (!timeout && i2c->msg_num) {
++ i2c_pxa_scream_blue_murder(i2c, "timeout");
++ ret = I2C_RETRY;
++ }
++
++ out:
++ return ret;
++}
+
+ static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+ {
+@@ -1132,6 +1034,103 @@ static const struct i2c_algorithm i2c_pxa_algorithm = {
+ .functionality = i2c_pxa_functionality,
+ };
+
++/* Non-interrupt mode support */
++static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
++{
++ /* make timeout the same as for interrupt based functions */
++ long timeout = 2 * DEF_TIMEOUT;
++
++ /*
++ * Wait for the bus to become free.
++ */
++ while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
++ udelay(1000);
++ show_state(i2c);
++ }
++
++ if (timeout < 0) {
++ show_state(i2c);
++ dev_err(&i2c->adap.dev,
++ "i2c_pxa: timeout waiting for bus free\n");
++ return I2C_RETRY;
++ }
++
++ /*
++ * Set master mode.
++ */
++ writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
++
++ return 0;
++}
++
++static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
++ struct i2c_msg *msg, int num)
++{
++ unsigned long timeout = 500000; /* 5 seconds */
++ int ret = 0;
++
++ ret = i2c_pxa_pio_set_master(i2c);
++ if (ret)
++ goto out;
++
++ i2c->msg = msg;
++ i2c->msg_num = num;
++ i2c->msg_idx = 0;
++ i2c->msg_ptr = 0;
++ i2c->irqlogidx = 0;
++
++ i2c_pxa_start_message(i2c);
++
++ while (i2c->msg_num > 0 && --timeout) {
++ i2c_pxa_handler(0, i2c);
++ udelay(10);
++ }
++
++ i2c_pxa_stop_message(i2c);
++
++ /*
++ * We place the return code in i2c->msg_idx.
++ */
++ ret = i2c->msg_idx;
++
++out:
++ if (timeout == 0) {
++ i2c_pxa_scream_blue_murder(i2c, "timeout");
++ ret = I2C_RETRY;
++ }
++
++ return ret;
++}
++
++static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
++ struct i2c_msg msgs[], int num)
++{
++ struct pxa_i2c *i2c = adap->algo_data;
++ int ret, i;
++
++ /* If the I2C controller is disabled we need to reset it
++ (probably due to a suspend/resume destroying state). We do
++ this here as we can then avoid worrying about resuming the
++ controller before its users. */
++ if (!(readl(_ICR(i2c)) & ICR_IUE))
++ i2c_pxa_reset(i2c);
++
++ for (i = adap->retries; i >= 0; i--) {
++ ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
++ if (ret != I2C_RETRY)
++ goto out;
++
++ if (i2c_debug)
++ dev_dbg(&adap->dev, "Retrying transmission\n");
++ udelay(100);
++ }
++ i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
++ ret = -EREMOTEIO;
++ out:
++ i2c_pxa_set_slave(i2c, ret);
++ return ret;
++}
++
+ static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
+ .master_xfer = i2c_pxa_pio_xfer,
+ .functionality = i2c_pxa_functionality,
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/807-v5.8-i2c-pxa-re-arrange-register-field-definitions.patch b/target/linux/generic/backport-5.4/807-v5.8-i2c-pxa-re-arrange-register-field-definitions.patch
new file mode 100644
index 000000000000..348da2a5f2f2
--- /dev/null
+++ b/target/linux/generic/backport-5.4/807-v5.8-i2c-pxa-re-arrange-register-field-definitions.patch
@@ -0,0 +1,166 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Cc: linux-i2c at vger.kernel.org
+Subject: [PATCH 05/17] i2c: pxa: re-arrange register field definitions
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Arrange the register field definitions to be grouped together, rather
+than the Armada-3700 definitions being separated from the rest of the
+definitions.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 113 ++++++++++++++++-------------------
+ 1 file changed, 53 insertions(+), 60 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index e5f00ae39861..ea96dfa6b9d5 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -33,6 +33,56 @@
+ #include <linux/platform_data/i2c-pxa.h>
+ #include <linux/slab.h>
+
++/* I2C register field definitions */
++#define ICR_START (1 << 0) /* start bit */
++#define ICR_STOP (1 << 1) /* stop bit */
++#define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */
++#define ICR_TB (1 << 3) /* transfer byte bit */
++#define ICR_MA (1 << 4) /* master abort */
++#define ICR_SCLE (1 << 5) /* master clock enable */
++#define ICR_IUE (1 << 6) /* unit enable */
++#define ICR_GCD (1 << 7) /* general call disable */
++#define ICR_ITEIE (1 << 8) /* enable tx interrupts */
++#define ICR_IRFIE (1 << 9) /* enable rx interrupts */
++#define ICR_BEIE (1 << 10) /* enable bus error ints */
++#define ICR_SSDIE (1 << 11) /* slave STOP detected int enable */
++#define ICR_ALDIE (1 << 12) /* enable arbitration interrupt */
++#define ICR_SADIE (1 << 13) /* slave address detected int enable */
++#define ICR_UR (1 << 14) /* unit reset */
++#define ICR_FM (1 << 15) /* fast mode */
++#define ICR_HS (1 << 16) /* High Speed mode */
++#define ICR_A3700_FM (1 << 16) /* fast mode for armada-3700 */
++#define ICR_A3700_HS (1 << 17) /* high speed mode for armada-3700 */
++#define ICR_GPIOEN (1 << 19) /* enable GPIO mode for SCL in HS */
++
++#define ISR_RWM (1 << 0) /* read/write mode */
++#define ISR_ACKNAK (1 << 1) /* ack/nak status */
++#define ISR_UB (1 << 2) /* unit busy */
++#define ISR_IBB (1 << 3) /* bus busy */
++#define ISR_SSD (1 << 4) /* slave stop detected */
++#define ISR_ALD (1 << 5) /* arbitration loss detected */
++#define ISR_ITE (1 << 6) /* tx buffer empty */
++#define ISR_IRF (1 << 7) /* rx buffer full */
++#define ISR_GCAD (1 << 8) /* general call address detected */
++#define ISR_SAD (1 << 9) /* slave address detected */
++#define ISR_BED (1 << 10) /* bus error no ACK/NAK */
++
++#define ILCR_SLV_SHIFT 0
++#define ILCR_SLV_MASK (0x1FF << ILCR_SLV_SHIFT)
++#define ILCR_FLV_SHIFT 9
++#define ILCR_FLV_MASK (0x1FF << ILCR_FLV_SHIFT)
++#define ILCR_HLVL_SHIFT 18
++#define ILCR_HLVL_MASK (0x1FF << ILCR_HLVL_SHIFT)
++#define ILCR_HLVH_SHIFT 27
++#define ILCR_HLVH_MASK (0x1F << ILCR_HLVH_SHIFT)
++
++#define IWCR_CNT_SHIFT 0
++#define IWCR_CNT_MASK (0x1F << IWCR_CNT_SHIFT)
++#define IWCR_HS_CNT1_SHIFT 5
++#define IWCR_HS_CNT1_MASK (0x1F << IWCR_HS_CNT1_SHIFT)
++#define IWCR_HS_CNT2_SHIFT 10
++#define IWCR_HS_CNT2_MASK (0x1F << IWCR_HS_CNT2_SHIFT)
++
+ struct pxa_reg_layout {
+ u32 ibmr;
+ u32 idbr;
+@@ -53,12 +103,7 @@ enum pxa_i2c_types {
+ REGS_A3700,
+ };
+
+-#define ICR_BUSMODE_FM (1 << 16) /* shifted fast mode for armada-3700 */
+-#define ICR_BUSMODE_HS (1 << 17) /* shifted high speed mode for armada-3700 */
+-
+-/*
+- * I2C registers definitions
+- */
++/* I2C register layout definitions */
+ static struct pxa_reg_layout pxa_reg_layout[] = {
+ [REGS_PXA2XX] = {
+ .ibmr = 0x00,
+@@ -96,8 +141,8 @@ static struct pxa_reg_layout pxa_reg_layout[] = {
+ .icr = 0x08,
+ .isr = 0x0c,
+ .isar = 0x10,
+- .fm = ICR_BUSMODE_FM,
+- .hs = ICR_BUSMODE_HS,
++ .fm = ICR_A3700_FM,
++ .hs = ICR_A3700_HS,
+ },
+ };
+
+@@ -111,58 +156,6 @@ static const struct platform_device_id i2c_pxa_id_table[] = {
+ };
+ MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
+
+-/*
+- * I2C bit definitions
+- */
+-
+-#define ICR_START (1 << 0) /* start bit */
+-#define ICR_STOP (1 << 1) /* stop bit */
+-#define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */
+-#define ICR_TB (1 << 3) /* transfer byte bit */
+-#define ICR_MA (1 << 4) /* master abort */
+-#define ICR_SCLE (1 << 5) /* master clock enable */
+-#define ICR_IUE (1 << 6) /* unit enable */
+-#define ICR_GCD (1 << 7) /* general call disable */
+-#define ICR_ITEIE (1 << 8) /* enable tx interrupts */
+-#define ICR_IRFIE (1 << 9) /* enable rx interrupts */
+-#define ICR_BEIE (1 << 10) /* enable bus error ints */
+-#define ICR_SSDIE (1 << 11) /* slave STOP detected int enable */
+-#define ICR_ALDIE (1 << 12) /* enable arbitration interrupt */
+-#define ICR_SADIE (1 << 13) /* slave address detected int enable */
+-#define ICR_UR (1 << 14) /* unit reset */
+-#define ICR_FM (1 << 15) /* fast mode */
+-#define ICR_HS (1 << 16) /* High Speed mode */
+-#define ICR_GPIOEN (1 << 19) /* enable GPIO mode for SCL in HS */
+-
+-#define ISR_RWM (1 << 0) /* read/write mode */
+-#define ISR_ACKNAK (1 << 1) /* ack/nak status */
+-#define ISR_UB (1 << 2) /* unit busy */
+-#define ISR_IBB (1 << 3) /* bus busy */
+-#define ISR_SSD (1 << 4) /* slave stop detected */
+-#define ISR_ALD (1 << 5) /* arbitration loss detected */
+-#define ISR_ITE (1 << 6) /* tx buffer empty */
+-#define ISR_IRF (1 << 7) /* rx buffer full */
+-#define ISR_GCAD (1 << 8) /* general call address detected */
+-#define ISR_SAD (1 << 9) /* slave address detected */
+-#define ISR_BED (1 << 10) /* bus error no ACK/NAK */
+-
+-/* bit field shift & mask */
+-#define ILCR_SLV_SHIFT 0
+-#define ILCR_SLV_MASK (0x1FF << ILCR_SLV_SHIFT)
+-#define ILCR_FLV_SHIFT 9
+-#define ILCR_FLV_MASK (0x1FF << ILCR_FLV_SHIFT)
+-#define ILCR_HLVL_SHIFT 18
+-#define ILCR_HLVL_MASK (0x1FF << ILCR_HLVL_SHIFT)
+-#define ILCR_HLVH_SHIFT 27
+-#define ILCR_HLVH_MASK (0x1F << ILCR_HLVH_SHIFT)
+-
+-#define IWCR_CNT_SHIFT 0
+-#define IWCR_CNT_MASK (0x1F << IWCR_CNT_SHIFT)
+-#define IWCR_HS_CNT1_SHIFT 5
+-#define IWCR_HS_CNT1_MASK (0x1F << IWCR_HS_CNT1_SHIFT)
+-#define IWCR_HS_CNT2_SHIFT 10
+-#define IWCR_HS_CNT2_MASK (0x1F << IWCR_HS_CNT2_SHIFT)
+-
+ struct pxa_i2c {
+ spinlock_t lock;
+ wait_queue_head_t wait;
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/808-v5.8-i2c-pxa-add-and-use-definitions-for-IBMR-register.patch b/target/linux/generic/backport-5.4/808-v5.8-i2c-pxa-add-and-use-definitions-for-IBMR-register.patch
new file mode 100644
index 000000000000..9d7c50164025
--- /dev/null
+++ b/target/linux/generic/backport-5.4/808-v5.8-i2c-pxa-add-and-use-definitions-for-IBMR-register.patch
@@ -0,0 +1,71 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Cc: linux-i2c at vger.kernel.org
+Subject: [PATCH 06/17] i2c: pxa: add and use definitions for IBMR register
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Add definitions for the bits in the IBMR register, and use them in the
+code. This improves readability.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 12 ++++++++----
+ 1 file changed, 8 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index ea96dfa6b9d5..b3286d7ab75d 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -34,6 +34,9 @@
+ #include <linux/slab.h>
+
+ /* I2C register field definitions */
++#define IBMR_SDAS (1 << 0)
++#define IBMR_SCLS (1 << 1)
++
+ #define ICR_START (1 << 0) /* start bit */
+ #define ICR_STOP (1 << 1) /* stop bit */
+ #define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */
+@@ -335,7 +338,7 @@ static void i2c_pxa_abort(struct pxa_i2c *i2c)
+ return;
+ }
+
+- while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
++ while ((i > 0) && (readl(_IBMR(i2c)) & IBMR_SDAS) == 0) {
+ unsigned long icr = readl(_ICR(i2c));
+
+ icr &= ~ICR_START;
+@@ -390,7 +393,8 @@ static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
+ * quick check of the i2c lines themselves to ensure they've
+ * gone high...
+ */
+- if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
++ if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 &&
++ readl(_IBMR(i2c)) == (IBMR_SCLS | IBMR_SDAS)) {
+ if (i2c_debug > 0)
+ dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
+ return 1;
+@@ -575,7 +579,7 @@ static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
+ timeout = 0x10000;
+
+ while (1) {
+- if ((readl(_IBMR(i2c)) & 2) == 2)
++ if ((readl(_IBMR(i2c)) & IBMR_SCLS) == IBMR_SCLS)
+ break;
+
+ timeout--;
+@@ -638,7 +642,7 @@ static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
+ timeout = 0x10000;
+
+ while (1) {
+- if ((readl(_IBMR(i2c)) & 2) == 2)
++ if ((readl(_IBMR(i2c)) & IBMR_SCLS) == IBMR_SCLS)
+ break;
+
+ timeout--;
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/809-v5.8-i2c-pxa-always-set-fm-and-hs-members-for-each-type.patch b/target/linux/generic/backport-5.4/809-v5.8-i2c-pxa-always-set-fm-and-hs-members-for-each-type.patch
new file mode 100644
index 000000000000..2e98c7ba00bd
--- /dev/null
+++ b/target/linux/generic/backport-5.4/809-v5.8-i2c-pxa-always-set-fm-and-hs-members-for-each-type.patch
@@ -0,0 +1,71 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Cc: linux-i2c at vger.kernel.org
+Subject: [PATCH 07/17] i2c: pxa: always set fm and hs members for each type
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Always set the fm and hs members of struct pxa_reg_layout. These
+members are already taking space, we don't need code as well.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 12 ++++++++++--
+ 1 file changed, 10 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index b3286d7ab75d..05dbe6bf4633 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -114,6 +114,8 @@ static struct pxa_reg_layout pxa_reg_layout[] = {
+ .icr = 0x10,
+ .isr = 0x18,
+ .isar = 0x20,
++ .fm = ICR_FM,
++ .hs = ICR_HS,
+ },
+ [REGS_PXA3XX] = {
+ .ibmr = 0x00,
+@@ -121,6 +123,8 @@ static struct pxa_reg_layout pxa_reg_layout[] = {
+ .icr = 0x08,
+ .isr = 0x0c,
+ .isar = 0x10,
++ .fm = ICR_FM,
++ .hs = ICR_HS,
+ },
+ [REGS_CE4100] = {
+ .ibmr = 0x14,
+@@ -128,6 +132,8 @@ static struct pxa_reg_layout pxa_reg_layout[] = {
+ .icr = 0x00,
+ .isr = 0x04,
+ /* no isar register */
++ .fm = ICR_FM,
++ .hs = ICR_HS,
+ },
+ [REGS_PXA910] = {
+ .ibmr = 0x00,
+@@ -137,6 +143,8 @@ static struct pxa_reg_layout pxa_reg_layout[] = {
+ .isar = 0x20,
+ .ilcr = 0x28,
+ .iwcr = 0x30,
++ .fm = ICR_FM,
++ .hs = ICR_HS,
+ },
+ [REGS_A3700] = {
+ .ibmr = 0x00,
+@@ -1235,8 +1243,8 @@ static int i2c_pxa_probe(struct platform_device *dev)
+ i2c->reg_idbr = i2c->reg_base + pxa_reg_layout[i2c_type].idbr;
+ i2c->reg_icr = i2c->reg_base + pxa_reg_layout[i2c_type].icr;
+ i2c->reg_isr = i2c->reg_base + pxa_reg_layout[i2c_type].isr;
+- i2c->fm_mask = pxa_reg_layout[i2c_type].fm ? : ICR_FM;
+- i2c->hs_mask = pxa_reg_layout[i2c_type].hs ? : ICR_HS;
++ i2c->fm_mask = pxa_reg_layout[i2c_type].fm;
++ i2c->hs_mask = pxa_reg_layout[i2c_type].hs;
+
+ if (i2c_type != REGS_CE4100)
+ i2c->reg_isar = i2c->reg_base + pxa_reg_layout[i2c_type].isar;
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/810-v5.8-i2c-pxa-move-private-definitions-to-i2c-pxa.c.patch b/target/linux/generic/backport-5.4/810-v5.8-i2c-pxa-move-private-definitions-to-i2c-pxa.c.patch
new file mode 100644
index 000000000000..a7bbdd954608
--- /dev/null
+++ b/target/linux/generic/backport-5.4/810-v5.8-i2c-pxa-move-private-definitions-to-i2c-pxa.c.patch
@@ -0,0 +1,135 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Cc: linux-i2c at vger.kernel.org
+Subject: [PATCH 08/17] i2c: pxa: move private definitions to i2c-pxa.c
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Move driver-private definitions out of the i2c-pxa.h platform data
+header file into the driver itself. Nothing outside of the driver
+makes use of these constants.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 43 ++++++++++++++++++++++++
+ include/linux/platform_data/i2c-pxa.h | 48 ---------------------------
+ 2 files changed, 43 insertions(+), 48 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index 05dbe6bf4633..482768a9fdd2 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -86,6 +86,49 @@
+ #define IWCR_HS_CNT2_SHIFT 10
+ #define IWCR_HS_CNT2_MASK (0x1F << IWCR_HS_CNT2_SHIFT)
+
++/* need a longer timeout if we're dealing with the fact we may well be
++ * looking at a multi-master environment
++ */
++#define DEF_TIMEOUT 32
++
++#define BUS_ERROR (-EREMOTEIO)
++#define XFER_NAKED (-ECONNREFUSED)
++#define I2C_RETRY (-2000) /* an error has occurred retry transmit */
++
++/* ICR initialize bit values
++ *
++ * 15 FM 0 (100 kHz operation)
++ * 14 UR 0 (No unit reset)
++ * 13 SADIE 0 (Disables the unit from interrupting on slave addresses
++ * matching its slave address)
++ * 12 ALDIE 0 (Disables the unit from interrupt when it loses arbitration
++ * in master mode)
++ * 11 SSDIE 0 (Disables interrupts from a slave stop detected, in slave mode)
++ * 10 BEIE 1 (Enable interrupts from detected bus errors, no ACK sent)
++ * 9 IRFIE 1 (Enable interrupts from full buffer received)
++ * 8 ITEIE 1 (Enables the I2C unit to interrupt when transmit buffer empty)
++ * 7 GCD 1 (Disables i2c unit response to general call messages as a slave)
++ * 6 IUE 0 (Disable unit until we change settings)
++ * 5 SCLE 1 (Enables the i2c clock output for master mode (drives SCL)
++ * 4 MA 0 (Only send stop with the ICR stop bit)
++ * 3 TB 0 (We are not transmitting a byte initially)
++ * 2 ACKNAK 0 (Send an ACK after the unit receives a byte)
++ * 1 STOP 0 (Do not send a STOP)
++ * 0 START 0 (Do not send a START)
++ */
++#define I2C_ICR_INIT (ICR_BEIE | ICR_IRFIE | ICR_ITEIE | ICR_GCD | ICR_SCLE)
++
++/* I2C status register init values
++ *
++ * 10 BED 1 (Clear bus error detected)
++ * 9 SAD 1 (Clear slave address detected)
++ * 7 IRF 1 (Clear IDBR Receive Full)
++ * 6 ITE 1 (Clear IDBR Transmit Empty)
++ * 5 ALD 1 (Clear Arbitration Loss Detected)
++ * 4 SSD 1 (Clear Slave Stop Detected)
++ */
++#define I2C_ISR_INIT 0x7FF /* status register init */
++
+ struct pxa_reg_layout {
+ u32 ibmr;
+ u32 idbr;
+diff --git a/include/linux/platform_data/i2c-pxa.h b/include/linux/platform_data/i2c-pxa.h
+index cb290092599c..5c08a6ff3444 100644
+--- a/include/linux/platform_data/i2c-pxa.h
++++ b/include/linux/platform_data/i2c-pxa.h
+@@ -7,54 +7,6 @@
+ #ifndef _I2C_PXA_H_
+ #define _I2C_PXA_H_
+
+-#if 0
+-#define DEF_TIMEOUT 3
+-#else
+-/* need a longer timeout if we're dealing with the fact we may well be
+- * looking at a multi-master environment
+-*/
+-#define DEF_TIMEOUT 32
+-#endif
+-
+-#define BUS_ERROR (-EREMOTEIO)
+-#define XFER_NAKED (-ECONNREFUSED)
+-#define I2C_RETRY (-2000) /* an error has occurred retry transmit */
+-
+-/* ICR initialize bit values
+-*
+-* 15. FM 0 (100 Khz operation)
+-* 14. UR 0 (No unit reset)
+-* 13. SADIE 0 (Disables the unit from interrupting on slave addresses
+-* matching its slave address)
+-* 12. ALDIE 0 (Disables the unit from interrupt when it loses arbitration
+-* in master mode)
+-* 11. SSDIE 0 (Disables interrupts from a slave stop detected, in slave mode)
+-* 10. BEIE 1 (Enable interrupts from detected bus errors, no ACK sent)
+-* 9. IRFIE 1 (Enable interrupts from full buffer received)
+-* 8. ITEIE 1 (Enables the I2C unit to interrupt when transmit buffer empty)
+-* 7. GCD 1 (Disables i2c unit response to general call messages as a slave)
+-* 6. IUE 0 (Disable unit until we change settings)
+-* 5. SCLE 1 (Enables the i2c clock output for master mode (drives SCL)
+-* 4. MA 0 (Only send stop with the ICR stop bit)
+-* 3. TB 0 (We are not transmitting a byte initially)
+-* 2. ACKNAK 0 (Send an ACK after the unit receives a byte)
+-* 1. STOP 0 (Do not send a STOP)
+-* 0. START 0 (Do not send a START)
+-*
+-*/
+-#define I2C_ICR_INIT (ICR_BEIE | ICR_IRFIE | ICR_ITEIE | ICR_GCD | ICR_SCLE)
+-
+-/* I2C status register init values
+- *
+- * 10. BED 1 (Clear bus error detected)
+- * 9. SAD 1 (Clear slave address detected)
+- * 7. IRF 1 (Clear IDBR Receive Full)
+- * 6. ITE 1 (Clear IDBR Transmit Empty)
+- * 5. ALD 1 (Clear Arbitration Loss Detected)
+- * 4. SSD 1 (Clear Slave Stop Detected)
+- */
+-#define I2C_ISR_INIT 0x7FF /* status register init */
+-
+ struct i2c_slave_client;
+
+ struct i2c_pxa_platform_data {
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/811-v5.8-i2c-pxa-move-DT-IDs-along-side-platform-IDs.patch b/target/linux/generic/backport-5.4/811-v5.8-i2c-pxa-move-DT-IDs-along-side-platform-IDs.patch
new file mode 100644
index 000000000000..3f1b96a8d6b9
--- /dev/null
+++ b/target/linux/generic/backport-5.4/811-v5.8-i2c-pxa-move-DT-IDs-along-side-platform-IDs.patch
@@ -0,0 +1,55 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Cc: linux-i2c at vger.kernel.org
+Subject: [PATCH 09/17] i2c: pxa: move DT IDs along side platform IDs
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Move the ID tables into one place, near the device dependent data.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 18 +++++++++---------
+ 1 file changed, 9 insertions(+), 9 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index 482768a9fdd2..760a29fb6af5 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -200,6 +200,15 @@ static struct pxa_reg_layout pxa_reg_layout[] = {
+ },
+ };
+
++static const struct of_device_id i2c_pxa_dt_ids[] = {
++ { .compatible = "mrvl,pxa-i2c", .data = (void *)REGS_PXA2XX },
++ { .compatible = "mrvl,pwri2c", .data = (void *)REGS_PXA3XX },
++ { .compatible = "mrvl,mmp-twsi", .data = (void *)REGS_PXA910 },
++ { .compatible = "marvell,armada-3700-i2c", .data = (void *)REGS_A3700 },
++ {}
++};
++MODULE_DEVICE_TABLE(of, i2c_pxa_dt_ids);
++
+ static const struct platform_device_id i2c_pxa_id_table[] = {
+ { "pxa2xx-i2c", REGS_PXA2XX },
+ { "pxa3xx-pwri2c", REGS_PXA3XX },
+@@ -1184,15 +1193,6 @@ static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
+ .functionality = i2c_pxa_functionality,
+ };
+
+-static const struct of_device_id i2c_pxa_dt_ids[] = {
+- { .compatible = "mrvl,pxa-i2c", .data = (void *)REGS_PXA2XX },
+- { .compatible = "mrvl,pwri2c", .data = (void *)REGS_PXA3XX },
+- { .compatible = "mrvl,mmp-twsi", .data = (void *)REGS_PXA910 },
+- { .compatible = "marvell,armada-3700-i2c", .data = (void *)REGS_A3700 },
+- {}
+-};
+-MODULE_DEVICE_TABLE(of, i2c_pxa_dt_ids);
+-
+ static int i2c_pxa_probe_dt(struct platform_device *pdev, struct pxa_i2c *i2c,
+ enum pxa_i2c_types *i2c_types)
+ {
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/812-v5.8-i2c-pxa-fix-i2c_pxa_scream_blue_murder-debug-output.patch b/target/linux/generic/backport-5.4/812-v5.8-i2c-pxa-fix-i2c_pxa_scream_blue_murder-debug-output.patch
new file mode 100644
index 000000000000..6c912e625490
--- /dev/null
+++ b/target/linux/generic/backport-5.4/812-v5.8-i2c-pxa-fix-i2c_pxa_scream_blue_murder-debug-output.patch
@@ -0,0 +1,52 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Cc: linux-i2c at vger.kernel.org
+Subject: [PATCH 10/17] i2c: pxa: fix i2c_pxa_scream_blue_murder() debug output
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+The IRQ log output is supposed to appear on a single line. However,
+commit 3a2dc1677b60 ("i2c: pxa: Update debug function to dump more info
+on error") resulted in it being printed one-entry-per-line, which is
+excessively long.
+
+Fixing this is not a trivial matter; using pr_cont() doesn't work as
+the previous dev_dbg() may not have been compiled in, or may be
+dynamic.
+
+Since the rest of this function output is at error level, and is also
+debug output, promote this to error level as well to avoid this
+problem.
+
+Reduce the number of always zero prefix digits to save screen real-
+estate.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 7 +++----
+ 1 file changed, 3 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index 760a29fb6af5..f3a11050053c 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -364,11 +364,10 @@ static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
+ dev_err(dev, "IBMR: %08x IDBR: %08x ICR: %08x ISR: %08x\n",
+ readl(_IBMR(i2c)), readl(_IDBR(i2c)), readl(_ICR(i2c)),
+ readl(_ISR(i2c)));
+- dev_dbg(dev, "log: ");
++ dev_err(dev, "log:");
+ for (i = 0; i < i2c->irqlogidx; i++)
+- pr_debug("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
+-
+- pr_debug("\n");
++ pr_cont(" [%03x:%05x]", i2c->isrlog[i], i2c->icrlog[i]);
++ pr_cont("\n");
+ }
+
+ #else /* ifdef DEBUG */
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/813-v5.8-i2c-pxa-clean-up-decode_bits.patch b/target/linux/generic/backport-5.4/813-v5.8-i2c-pxa-clean-up-decode_bits.patch
new file mode 100644
index 000000000000..552630eaf7d7
--- /dev/null
+++ b/target/linux/generic/backport-5.4/813-v5.8-i2c-pxa-clean-up-decode_bits.patch
@@ -0,0 +1,58 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Cc: linux-i2c at vger.kernel.org
+Subject: [PATCH 11/17] i2c: pxa: clean up decode_bits()
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Clean up decode_bits() to use pr_cont(), and move the newline into the
+function rather than at its two callsites. Avoid printing an
+unnecessary space before the newline.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 7 +++----
+ 1 file changed, 3 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index f3a11050053c..b2c7765756e2 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -287,13 +287,14 @@ struct bits {
+ static inline void
+ decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
+ {
+- printk("%s %08x: ", prefix, val);
++ printk("%s %08x:", prefix, val);
+ while (num--) {
+ const char *str = val & bits->mask ? bits->set : bits->unset;
+ if (str)
+- printk("%s ", str);
++ pr_cont(" %s", str);
+ bits++;
+ }
++ pr_cont("\n");
+ }
+
+ static const struct bits isr_bits[] = {
+@@ -313,7 +314,6 @@ static const struct bits isr_bits[] = {
+ static void decode_ISR(unsigned int val)
+ {
+ decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
+- printk("\n");
+ }
+
+ static const struct bits icr_bits[] = {
+@@ -338,7 +338,6 @@ static const struct bits icr_bits[] = {
+ static void decode_ICR(unsigned int val)
+ {
+ decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
+- printk("\n");
+ }
+ #endif
+
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/814-v5.8-i2c-pxa-fix-i2c_pxa_wait_bus_not_busy-boundary-condi.patch b/target/linux/generic/backport-5.4/814-v5.8-i2c-pxa-fix-i2c_pxa_wait_bus_not_busy-boundary-condi.patch
new file mode 100644
index 000000000000..d5aded5479cb
--- /dev/null
+++ b/target/linux/generic/backport-5.4/814-v5.8-i2c-pxa-fix-i2c_pxa_wait_bus_not_busy-boundary-condi.patch
@@ -0,0 +1,58 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Cc: linux-i2c at vger.kernel.org
+Subject: [PATCH 12/17] i2c: pxa: fix i2c_pxa_wait_bus_not_busy() boundary
+ condition
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Fix i2c_pxa_wait_bus_not_busy()'s boundary conditions, so that a
+coincidental success and timeout results in the function returning
+success.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 17 ++++++++++++-----
+ 1 file changed, 12 insertions(+), 5 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index b2c7765756e2..19505ffbb8f1 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -417,19 +417,26 @@ static void i2c_pxa_abort(struct pxa_i2c *i2c)
+ static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
+ {
+ int timeout = DEF_TIMEOUT;
++ u32 isr;
+
+- while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
+- if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
++ while (1) {
++ isr = readl(_ISR(i2c));
++ if (!(isr & (ISR_IBB | ISR_UB)))
++ return 0;
++
++ if (isr & ISR_SAD)
+ timeout += 4;
+
++ if (!timeout--)
++ break;
++
+ msleep(2);
+ show_state(i2c);
+ }
+
+- if (timeout < 0)
+- show_state(i2c);
++ show_state(i2c);
+
+- return timeout < 0 ? I2C_RETRY : 0;
++ return I2C_RETRY;
+ }
+
+ static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/815-v5.8-i2c-pxa-consolidate-i2c_pxa_-xfer-implementations.patch b/target/linux/generic/backport-5.4/815-v5.8-i2c-pxa-consolidate-i2c_pxa_-xfer-implementations.patch
new file mode 100644
index 000000000000..f66759f48bef
--- /dev/null
+++ b/target/linux/generic/backport-5.4/815-v5.8-i2c-pxa-consolidate-i2c_pxa_-xfer-implementations.patch
@@ -0,0 +1,96 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Subject: [PATCH 1/7] i2c: pxa: consolidate i2c_pxa_*xfer() implementations
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Most of i2c_pxa_pio_xfer() and i2c_pxa_xfer() are identical; the only
+differences are that i2c_pxa_pio_xfer() may reset the bus, and they
+use different underlying transfer functions. The retry loop is the
+same. Consolidate these two functions.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 36 ++++++++++++++++--------------------
+ 1 file changed, 16 insertions(+), 20 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index c1e50c0b9756..46f1cf97d955 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -1102,18 +1102,20 @@ static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
+ return ret;
+ }
+
+-static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
++static int i2c_pxa_internal_xfer(struct pxa_i2c *i2c,
++ struct i2c_msg *msgs, int num,
++ int (*xfer)(struct pxa_i2c *,
++ struct i2c_msg *, int num))
+ {
+- struct pxa_i2c *i2c = adap->algo_data;
+ int ret, i;
+
+- for (i = adap->retries; i >= 0; i--) {
+- ret = i2c_pxa_do_xfer(i2c, msgs, num);
++ for (i = i2c->adap.retries; i >= 0; i--) {
++ ret = xfer(i2c, msgs, num);
+ if (ret != I2C_RETRY)
+ goto out;
+
+ if (i2c_debug)
+- dev_dbg(&adap->dev, "Retrying transmission\n");
++ dev_dbg(&i2c->adap.dev, "Retrying transmission\n");
+ udelay(100);
+ }
+ i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
+@@ -1123,6 +1125,14 @@ static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num
+ return ret;
+ }
+
++static int i2c_pxa_xfer(struct i2c_adapter *adap,
++ struct i2c_msg msgs[], int num)
++{
++ struct pxa_i2c *i2c = adap->algo_data;
++
++ return i2c_pxa_internal_xfer(i2c, msgs, num, i2c_pxa_do_xfer);
++}
++
+ static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
+ {
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+@@ -1210,7 +1220,6 @@ static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
+ struct i2c_msg msgs[], int num)
+ {
+ struct pxa_i2c *i2c = adap->algo_data;
+- int ret, i;
+
+ /* If the I2C controller is disabled we need to reset it
+ (probably due to a suspend/resume destroying state). We do
+@@ -1219,20 +1228,7 @@ static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
+ if (!(readl(_ICR(i2c)) & ICR_IUE))
+ i2c_pxa_reset(i2c);
+
+- for (i = adap->retries; i >= 0; i--) {
+- ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
+- if (ret != I2C_RETRY)
+- goto out;
+-
+- if (i2c_debug)
+- dev_dbg(&adap->dev, "Retrying transmission\n");
+- udelay(100);
+- }
+- i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
+- ret = -EREMOTEIO;
+- out:
+- i2c_pxa_set_slave(i2c, ret);
+- return ret;
++ return i2c_pxa_internal_xfer(i2c, msgs, num, i2c_pxa_do_pio_xfer);
+ }
+
+ static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/816-v5.8-i2c-pxa-avoid-complaints-with-non-responsive-slaves.patch b/target/linux/generic/backport-5.4/816-v5.8-i2c-pxa-avoid-complaints-with-non-responsive-slaves.patch
new file mode 100644
index 000000000000..308dba0fb9ae
--- /dev/null
+++ b/target/linux/generic/backport-5.4/816-v5.8-i2c-pxa-avoid-complaints-with-non-responsive-slaves.patch
@@ -0,0 +1,72 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Subject: [PATCH 2/7] i2c: pxa: avoid complaints with non-responsive slaves
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Running i2cdetect on a PXA I2C adapter is very noisy; it complains
+whenever a slave fails to respond to the address cycle. Since it is
+normal to probe for slaves in this way, we should not fill the kernel
+log. This is especially true with SFP modules that take a while to
+respond on the I2C bus, and probing via the I2C bus is the only way to
+detect that they are ready.
+
+Fix this by changing the internal transfer return code from I2C_RETRY
+to a new NO_SLAVE code (mapped to -ENXIO, as per the I2C documentation
+for this condition, but we still return -EREMOTEIO to the I2C stack to
+maintain long established driver behaviour.)
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 12 ++++++++----
+ 1 file changed, 8 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index 46f1cf97d955..f20f8b905793 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -90,6 +90,7 @@
+ */
+ #define DEF_TIMEOUT 32
+
++#define NO_SLAVE (-ENXIO)
+ #define BUS_ERROR (-EREMOTEIO)
+ #define XFER_NAKED (-ECONNREFUSED)
+ #define I2C_RETRY (-2000) /* an error has occurred retry transmit */
+@@ -881,7 +882,7 @@ static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
+ */
+ if (isr & ISR_ACKNAK) {
+ if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
+- ret = I2C_RETRY;
++ ret = NO_SLAVE;
+ else
+ ret = XFER_NAKED;
+ }
+@@ -1109,16 +1110,19 @@ static int i2c_pxa_internal_xfer(struct pxa_i2c *i2c,
+ {
+ int ret, i;
+
+- for (i = i2c->adap.retries; i >= 0; i--) {
++ for (i = 0; ; ) {
+ ret = xfer(i2c, msgs, num);
+- if (ret != I2C_RETRY)
++ if (ret != I2C_RETRY && ret != NO_SLAVE)
+ goto out;
++ if (++i >= i2c->adap.retries)
++ break;
+
+ if (i2c_debug)
+ dev_dbg(&i2c->adap.dev, "Retrying transmission\n");
+ udelay(100);
+ }
+- i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
++ if (ret != NO_SLAVE)
++ i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
+ ret = -EREMOTEIO;
+ out:
+ i2c_pxa_set_slave(i2c, ret);
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/817-v5.8-i2c-pxa-ensure-timeout-messages-are-unique.patch b/target/linux/generic/backport-5.4/817-v5.8-i2c-pxa-ensure-timeout-messages-are-unique.patch
new file mode 100644
index 000000000000..39ca935ae934
--- /dev/null
+++ b/target/linux/generic/backport-5.4/817-v5.8-i2c-pxa-ensure-timeout-messages-are-unique.patch
@@ -0,0 +1,50 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Subject: [PATCH 3/7] i2c: pxa: ensure timeout messages are unique
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Ensure that the various timeout messages can identify where in the code
+they were produced from to aid debugging.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index f20f8b905793..0becab239476 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -1095,7 +1095,7 @@ static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
+ ret = i2c->msg_idx;
+
+ if (!timeout && i2c->msg_num) {
+- i2c_pxa_scream_blue_murder(i2c, "timeout");
++ i2c_pxa_scream_blue_murder(i2c, "timeout with active message");
+ ret = I2C_RETRY;
+ }
+
+@@ -1169,7 +1169,7 @@ static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
+ if (timeout < 0) {
+ show_state(i2c);
+ dev_err(&i2c->adap.dev,
+- "i2c_pxa: timeout waiting for bus free\n");
++ "i2c_pxa: timeout waiting for bus free (set_master)\n");
+ return I2C_RETRY;
+ }
+
+@@ -1213,7 +1213,7 @@ static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
+
+ out:
+ if (timeout == 0) {
+- i2c_pxa_scream_blue_murder(i2c, "timeout");
++ i2c_pxa_scream_blue_murder(i2c, "timeout (do_pio_xfer)");
+ ret = I2C_RETRY;
+ }
+
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/818-v5.8-i2c-pxa-remove-some-unnecessary-debug.patch b/target/linux/generic/backport-5.4/818-v5.8-i2c-pxa-remove-some-unnecessary-debug.patch
new file mode 100644
index 000000000000..4676d7721f4d
--- /dev/null
+++ b/target/linux/generic/backport-5.4/818-v5.8-i2c-pxa-remove-some-unnecessary-debug.patch
@@ -0,0 +1,39 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Subject: [PATCH 4/7] i2c: pxa: remove some unnecessary debug
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Remove unnecessary show_state() in the loop inside
+i2c_pxa_pio_set_master(), which can be unnecessarily verbose.
+
+Remove the i2c_pxa_scream_blue_murder() in i2c_pxa_pio_xfer(), which
+will trigger if we are probing the I2C bus and a slave does not
+respond; this is a normal event, and not something to report.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 4 +---
+ 1 file changed, 1 insertion(+), 3 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index 0becab239476..db739cce93ac 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -1161,10 +1161,8 @@ static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
+ /*
+ * Wait for the bus to become free.
+ */
+- while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
++ while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB))
+ udelay(1000);
+- show_state(i2c);
+- }
+
+ if (timeout < 0) {
+ show_state(i2c);
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/819-v5.8-i2c-pxa-clear-all-master-action-bits-in-i2c_pxa_stop.patch b/target/linux/generic/backport-5.4/819-v5.8-i2c-pxa-clear-all-master-action-bits-in-i2c_pxa_stop.patch
new file mode 100644
index 000000000000..997670716f2f
--- /dev/null
+++ b/target/linux/generic/backport-5.4/819-v5.8-i2c-pxa-clear-all-master-action-bits-in-i2c_pxa_stop.patch
@@ -0,0 +1,43 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Subject: [PATCH 5/7] i2c: pxa: clear all master action bits in
+ i2c_pxa_stop_message()
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+If we timeout during a message transfer, the control register may
+contain bits that cause an action to be set. Read-modify-writing the
+register leaving these bits set may trigger the hardware to attempt
+one of these actions unintentionally.
+
+Always clear these bits when cleaning up after a message or after
+a timeout.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 6 ++----
+ 1 file changed, 2 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index db739cce93ac..a72d07bdb793 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -795,11 +795,9 @@ static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
+ {
+ u32 icr;
+
+- /*
+- * Clear the STOP and ACK flags
+- */
++ /* Clear the START, STOP, ACK, TB and MA flags */
+ icr = readl(_ICR(i2c));
+- icr &= ~(ICR_STOP | ICR_ACKNAK);
++ icr &= ~(ICR_START | ICR_STOP | ICR_ACKNAK | ICR_TB | ICR_MA);
+ writel(icr, _ICR(i2c));
+ }
+
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/820-v5.8-i2c-pxa-use-master-abort-for-device-probes.patch b/target/linux/generic/backport-5.4/820-v5.8-i2c-pxa-use-master-abort-for-device-probes.patch
new file mode 100644
index 000000000000..2fde9e7322ce
--- /dev/null
+++ b/target/linux/generic/backport-5.4/820-v5.8-i2c-pxa-use-master-abort-for-device-probes.patch
@@ -0,0 +1,40 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Subject: [PATCH 6/7] i2c: pxa: use master-abort for device probes
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Use master-abort to send the stop condition after an address cycle
+rather than resetting the controller.
+
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 10 ++--------
+ 1 file changed, 2 insertions(+), 8 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index a72d07bdb793..0e194d6cd1b5 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -940,14 +940,8 @@ static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
+ icr &= ~ICR_ALDIE;
+ icr |= ICR_START | ICR_TB;
+ } else {
+- if (i2c->msg->len == 0) {
+- /*
+- * Device probes have a message length of zero
+- * and need the bus to be reset before it can
+- * be used again.
+- */
+- i2c_pxa_reset(i2c);
+- }
++ if (i2c->msg->len == 0)
++ icr |= ICR_MA;
+ i2c_pxa_master_complete(i2c, 0);
+ }
+
+--
+2.20.1
+
diff --git a/target/linux/generic/backport-5.4/821-v5.8-i2c-pxa-implement-generic-i2c-bus-recovery.patch b/target/linux/generic/backport-5.4/821-v5.8-i2c-pxa-implement-generic-i2c-bus-recovery.patch
new file mode 100644
index 000000000000..745cb6567c1b
--- /dev/null
+++ b/target/linux/generic/backport-5.4/821-v5.8-i2c-pxa-implement-generic-i2c-bus-recovery.patch
@@ -0,0 +1,290 @@
+From: Russell King <rmk+kernel at armlinux.org.uk>
+Bcc: linux at mail.armlinux.org.uk
+Subject: [PATCH 7/7] i2c: pxa: implement generic i2c bus recovery
+MIME-Version: 1.0
+Content-Disposition: inline
+Content-Transfer-Encoding: 8bit
+Content-Type: text/plain; charset="utf-8"
+
+Implement generic GPIO-based I2C bus recovery for the PXA I2C driver.
+
+Reviewed-by: Andrew Lunn <andrew at lunn.ch>
+Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
+---
+ drivers/i2c/busses/i2c-pxa.c | 176 +++++++++++++++++++++++++++++++----
+ 1 file changed, 159 insertions(+), 17 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
+index 0e194d6cd1b5..a7885b8b5031 100644
+--- a/drivers/i2c/busses/i2c-pxa.c
++++ b/drivers/i2c/busses/i2c-pxa.c
+@@ -20,6 +20,7 @@
+ #include <linux/delay.h>
+ #include <linux/err.h>
+ #include <linux/errno.h>
++#include <linux/gpio/consumer.h>
+ #include <linux/i2c.h>
+ #include <linux/init.h>
+ #include <linux/interrupt.h>
+@@ -28,6 +29,7 @@
+ #include <linux/module.h>
+ #include <linux/of.h>
+ #include <linux/of_device.h>
++#include <linux/pinctrl/consumer.h>
+ #include <linux/platform_device.h>
+ #include <linux/platform_data/i2c-pxa.h>
+ #include <linux/slab.h>
+@@ -260,6 +262,11 @@ struct pxa_i2c {
+ bool highmode_enter;
+ u32 fm_mask;
+ u32 hs_mask;
++
++ struct i2c_bus_recovery_info recovery;
++ struct pinctrl *pinctrl;
++ struct pinctrl_state *pinctrl_default;
++ struct pinctrl_state *pinctrl_recovery;
+ };
+
+ #define _IBMR(i2c) ((i2c)->reg_ibmr)
+@@ -559,13 +566,8 @@ static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
+ #define i2c_pxa_set_slave(i2c, err) do { } while (0)
+ #endif
+
+-static void i2c_pxa_reset(struct pxa_i2c *i2c)
++static void i2c_pxa_do_reset(struct pxa_i2c *i2c)
+ {
+- pr_debug("Resetting I2C Controller Unit\n");
+-
+- /* abort any transfer currently under way */
+- i2c_pxa_abort(i2c);
+-
+ /* reset according to 9.8 */
+ writel(ICR_UR, _ICR(i2c));
+ writel(I2C_ISR_INIT, _ISR(i2c));
+@@ -584,12 +586,25 @@ static void i2c_pxa_reset(struct pxa_i2c *i2c)
+ #endif
+
+ i2c_pxa_set_slave(i2c, 0);
++}
+
++static void i2c_pxa_enable(struct pxa_i2c *i2c)
++{
+ /* enable unit */
+ writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
+ udelay(100);
+ }
+
++static void i2c_pxa_reset(struct pxa_i2c *i2c)
++{
++ pr_debug("Resetting I2C Controller Unit\n");
++
++ /* abort any transfer currently under way */
++ i2c_pxa_abort(i2c);
++ i2c_pxa_do_reset(i2c);
++ i2c_pxa_enable(i2c);
++}
++
+
+ #ifdef CONFIG_I2C_PXA_SLAVE
+ /*
+@@ -1043,6 +1058,7 @@ static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
+ ret = i2c_pxa_wait_bus_not_busy(i2c);
+ if (ret) {
+ dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
++ i2c_recover_bus(&i2c->adap);
+ goto out;
+ }
+
+@@ -1088,6 +1104,7 @@ static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
+
+ if (!timeout && i2c->msg_num) {
+ i2c_pxa_scream_blue_murder(i2c, "timeout with active message");
++ i2c_recover_bus(&i2c->adap);
+ ret = I2C_RETRY;
+ }
+
+@@ -1277,6 +1294,129 @@ static int i2c_pxa_probe_pdata(struct platform_device *pdev,
+ return 0;
+ }
+
++static void i2c_pxa_prepare_recovery(struct i2c_adapter *adap)
++{
++ struct pxa_i2c *i2c = adap->algo_data;
++ u32 ibmr = readl(_IBMR(i2c));
++
++ /*
++ * Program the GPIOs to reflect the current I2C bus state while
++ * we transition to recovery; this avoids glitching the bus.
++ */
++ gpiod_set_value(i2c->recovery.scl_gpiod, ibmr & IBMR_SCLS);
++ gpiod_set_value(i2c->recovery.sda_gpiod, ibmr & IBMR_SDAS);
++
++ WARN_ON(pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_recovery));
++}
++
++static void i2c_pxa_unprepare_recovery(struct i2c_adapter *adap)
++{
++ struct pxa_i2c *i2c = adap->algo_data;
++ u32 isr;
++
++ /*
++ * The bus should now be free. Clear up the I2C controller before
++ * handing control of the bus back to avoid the bus changing state.
++ */
++ isr = readl(_ISR(i2c));
++ if (isr & (ISR_UB | ISR_IBB)) {
++ dev_dbg(&i2c->adap.dev,
++ "recovery: resetting controller, ISR=0x%08x\n", isr);
++ i2c_pxa_do_reset(i2c);
++ }
++
++ WARN_ON(pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_default));
++
++ dev_dbg(&i2c->adap.dev, "recovery: IBMR 0x%08x ISR 0x%08x\n",
++ readl(_IBMR(i2c)), readl(_ISR(i2c)));
++
++ i2c_pxa_enable(i2c);
++}
++
++static int i2c_pxa_init_recovery(struct pxa_i2c *i2c)
++{
++ struct i2c_bus_recovery_info *bri = &i2c->recovery;
++ struct device *dev = i2c->adap.dev.parent;
++
++ /*
++ * When slave mode is enabled, we are not the only master on the bus.
++ * Bus recovery can only be performed when we are the master, which
++ * we can't be certain of. Therefore, when slave mode is enabled, do
++ * not configure bus recovery.
++ */
++ if (IS_ENABLED(CONFIG_I2C_PXA_SLAVE))
++ return 0;
++
++ i2c->pinctrl = devm_pinctrl_get(dev);
++ if (IS_ERR(i2c->pinctrl))
++ return PTR_ERR(i2c->pinctrl);
++
++ if (!i2c->pinctrl)
++ return 0;
++
++ i2c->pinctrl_default = pinctrl_lookup_state(i2c->pinctrl,
++ PINCTRL_STATE_DEFAULT);
++ i2c->pinctrl_recovery = pinctrl_lookup_state(i2c->pinctrl, "recovery");
++
++ if (IS_ERR(i2c->pinctrl_default) || IS_ERR(i2c->pinctrl_recovery)) {
++ dev_info(dev, "missing pinmux recovery information: %ld %ld\n",
++ PTR_ERR(i2c->pinctrl_default),
++ PTR_ERR(i2c->pinctrl_recovery));
++ return 0;
++ }
++
++ /*
++ * Claiming GPIOs can influence the pinmux state, and may glitch the
++ * I2C bus. Do this carefully.
++ */
++ bri->scl_gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
++ if (bri->scl_gpiod == ERR_PTR(-EPROBE_DEFER))
++ return -EPROBE_DEFER;
++ if (IS_ERR(bri->scl_gpiod)) {
++ dev_info(dev, "missing scl gpio recovery information: %pe\n",
++ bri->scl_gpiod);
++ return 0;
++ }
++
++ /*
++ * We have SCL. Pull SCL low and wait a bit so that SDA glitches
++ * have no effect.
++ */
++ gpiod_direction_output(bri->scl_gpiod, 0);
++ udelay(10);
++ bri->sda_gpiod = devm_gpiod_get(dev, "sda", GPIOD_OUT_HIGH_OPEN_DRAIN);
++
++ /* Wait a bit in case of a SDA glitch, and then release SCL. */
++ udelay(10);
++ gpiod_direction_output(bri->scl_gpiod, 1);
++
++ if (bri->sda_gpiod == ERR_PTR(-EPROBE_DEFER))
++ return -EPROBE_DEFER;
++
++ if (IS_ERR(bri->sda_gpiod)) {
++ dev_info(dev, "missing sda gpio recovery information: %pe\n",
++ bri->sda_gpiod);
++ return 0;
++ }
++
++ bri->prepare_recovery = i2c_pxa_prepare_recovery;
++ bri->unprepare_recovery = i2c_pxa_unprepare_recovery;
++ bri->recover_bus = i2c_generic_scl_recovery;
++
++ i2c->adap.bus_recovery_info = bri;
++
++ /*
++ * Claiming GPIOs can change the pinmux state, which confuses the
++ * pinctrl since pinctrl's idea of the current setting is unaffected
++ * by the pinmux change caused by claiming the GPIO. Work around that
++ * by switching pinctrl to the GPIO state here. We do it this way to
++ * avoid glitching the I2C bus.
++ */
++ pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_recovery);
++
++ return pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_default);
++}
++
+ static int i2c_pxa_probe(struct platform_device *dev)
+ {
+ struct i2c_pxa_platform_data *plat = dev_get_platdata(&dev->dev);
+@@ -1289,6 +1429,16 @@ static int i2c_pxa_probe(struct platform_device *dev)
+ if (!i2c)
+ return -ENOMEM;
+
++ /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
++ i2c->adap.nr = dev->id;
++ i2c->adap.owner = THIS_MODULE;
++ i2c->adap.retries = 5;
++ i2c->adap.algo_data = i2c;
++ i2c->adap.dev.parent = &dev->dev;
++#ifdef CONFIG_OF
++ i2c->adap.dev.of_node = dev->dev.of_node;
++#endif
++
+ res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ i2c->reg_base = devm_ioremap_resource(&dev->dev, res);
+ if (IS_ERR(i2c->reg_base))
+@@ -1298,8 +1448,9 @@ static int i2c_pxa_probe(struct platform_device *dev)
+ if (irq < 0)
+ return irq;
+
+- /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
+- i2c->adap.nr = dev->id;
++ ret = i2c_pxa_init_recovery(i2c);
++ if (ret)
++ return ret;
+
+ ret = i2c_pxa_probe_dt(dev, i2c, &i2c_type);
+ if (ret > 0)
+@@ -1307,9 +1458,6 @@ static int i2c_pxa_probe(struct platform_device *dev)
+ if (ret < 0)
+ return ret;
+
+- i2c->adap.owner = THIS_MODULE;
+- i2c->adap.retries = 5;
+-
+ spin_lock_init(&i2c->lock);
+ init_waitqueue_head(&i2c->wait);
+
+@@ -1375,12 +1523,6 @@ static int i2c_pxa_probe(struct platform_device *dev)
+
+ i2c_pxa_reset(i2c);
+
+- i2c->adap.algo_data = i2c;
+- i2c->adap.dev.parent = &dev->dev;
+-#ifdef CONFIG_OF
+- i2c->adap.dev.of_node = dev->dev.of_node;
+-#endif
+-
+ ret = i2c_add_numbered_adapter(&i2c->adap);
+ if (ret < 0)
+ goto ereqirq;
+--
+2.20.1
+
--
2.20.1
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