[OpenWrt-Devel] [PATCH 2/3] kernel: owl-loader for delayed Atheros ath9k fixup
Christian Lamparter
chunkeey at googlemail.com
Thu Apr 7 17:56:55 EDT 2016
Some devices (like the Cisco Meraki Z1 Cloud Managed Teleworker Gateway)
need to be able to initialize the PCIe wifi device. Normally, this is done
during the early stages of booting linux, because the necessary init code
is read from the memory mapped SPI and passed to pci_enable_ath9k_fixup.
However,this isn't possible for devices which have the init code for the
Atheros chip stored on NAND in an UBI volume. Hence, this module can be
used to initialze the chip when the user-space is ready to extract the
init code.
Signed-off-by: Christian Lamparter <chunkeey at googlemail.com>
---
I included the ath9k mailing list too as this deals with bootstrapping
ath9k cards and maybe someone there is interested as well?
Anyway, the original post and the following discussion can be found here:
<https://www.mail-archive.com/openwrt-devel@lists.openwrt.org/msg38296.html>
Note: We tried several methods to get the AR9280 to work. Initially, we
tried just a request_firmware_nowait from the device's init (z1_setup
in mach-z1.c), but this wasn't working. The issue is that openwrt has
no /sbin/hotplug helper [0] and procd doesn't scan the
/sys/class/firmware directory for already open request once it started.
We played around with different approaches, and also made a helper-script
to fulfill the outstanding requests on boot [1]. however we found no good
place for it in the start-up scripts. So that's why we developed
this owl-loader module, since it won't have to deal with any procd/hotplug
issues.
The original submission was ar71xx specific, but this was fixed.
This module should work on all architectures (lantiq?) and has no dependencies
for anything outside ath9k_platform_data.
[0] <https://www.kernel.org/doc/pending/hotplug.txt> section:
"A note about race conditions (or "why bother with netlink?"):"
details on why it is a bad idea to have /sbin/hotplug
[1] <https://github.com/riptidewave93/Openwrt-Z1/commit/9a38c60a1206b4010fbfb626fc7b2ec69bbe232a>
---
package/kernel/owl-loader/Makefile | 59 ++++++++
package/kernel/owl-loader/src/Makefile | 1 +
package/kernel/owl-loader/src/owl-loader.c | 212 +++++++++++++++++++++++++++++
3 files changed, 272 insertions(+)
create mode 100644 package/kernel/owl-loader/Makefile
create mode 100644 package/kernel/owl-loader/src/Makefile
create mode 100644 package/kernel/owl-loader/src/owl-loader.c
diff --git a/package/kernel/owl-loader/Makefile b/package/kernel/owl-loader/Makefile
new file mode 100644
index 0000000..f5a95e2
--- /dev/null
+++ b/package/kernel/owl-loader/Makefile
@@ -0,0 +1,59 @@
+#
+# Copyright (C) 2016 OpenWrt.org
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/kernel.mk
+
+PKG_NAME:=owl-loader
+PKG_RELEASE:=1
+
+include $(INCLUDE_DIR)/package.mk
+
+define KernelPackage/owl-loader
+ SUBMENU:=Network Support
+ TITLE:=Owl loader for initializing Atheros PCIe Wifi chips
+ DEPENDS:=@PCI_SUPPORT +kmod-ath9k
+ FILES:=$(PKG_BUILD_DIR)/owl-loader.ko
+ AUTOLOAD:=$(call AutoProbe,owl-loader)
+ KCONFIG:=
+endef
+
+define KernelPackage/owl-loader/description
+ Kernel module that helps to initialize certain Qualcomm
+ Atheros' PCIe Wifi chips, which have the pcie init data
+ stored together with the calibration data in the file
+ system.
+
+ This is necessary for devices like the Cisco Meraki Z1.
+endef
+
+EXTRA_KCONFIG:= \
+ CONFIG_OWL_LOADER=m
+
+EXTRA_CFLAGS:= \
+ $(patsubst CONFIG_%, -DCONFIG_%=1, $(patsubst %=m,%,$(filter %=m,$(EXTRA_KCONFIG)))) \
+ $(patsubst CONFIG_%, -DCONFIG_%=1, $(patsubst %=y,%,$(filter %=y,$(EXTRA_KCONFIG)))) \
+
+MAKE_OPTS:= \
+ ARCH="$(LINUX_KARCH)" \
+ CROSS_COMPILE="$(TARGET_CROSS)" \
+ SUBDIRS="$(PKG_BUILD_DIR)" \
+ EXTRA_CFLAGS="$(EXTRA_CFLAGS)" \
+ $(EXTRA_KCONFIG)
+
+define Build/Prepare
+ mkdir -p $(PKG_BUILD_DIR)
+ $(CP) ./src/* $(PKG_BUILD_DIR)/
+endef
+
+define Build/Compile
+ $(MAKE) -C "$(LINUX_DIR)" \
+ $(MAKE_OPTS) \
+ modules
+endef
+
+$(eval $(call KernelPackage,owl-loader))
diff --git a/package/kernel/owl-loader/src/Makefile b/package/kernel/owl-loader/src/Makefile
new file mode 100644
index 0000000..6b58276
--- /dev/null
+++ b/package/kernel/owl-loader/src/Makefile
@@ -0,0 +1 @@
+obj-${CONFIG_OWL_LOADER} += owl-loader.o
diff --git a/package/kernel/owl-loader/src/owl-loader.c b/package/kernel/owl-loader/src/owl-loader.c
new file mode 100644
index 0000000..81dc495
--- /dev/null
+++ b/package/kernel/owl-loader/src/owl-loader.c
@@ -0,0 +1,212 @@
+/*
+ * Initialize Owl Emulation Devices (PCIID: 168c:ff1c)
+ *
+ * Copyright (C) 2016 Christian Lamparter <chunkeey at googlemail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * Some devices (like the Cisco Meraki Z1 Cloud Managed Teleworker Gateway)
+ * need to be able to initialize the PCIe wifi device. Normally, this is done
+ * during the early stages of booting linux, because the necessary init code
+ * is read from the memory mapped SPI and passed to pci_enable_ath9k_fixup.
+ * However,this isn't possible for devices which have the init code for the
+ * Atheros chip stored on NAND. Hence, this module can be used to initialze
+ * the chip when the user-space is ready to extract the init code.
+ */
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/completion.h>
+#include <linux/firmware.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/ath9k_platform.h>
+
+struct owl_ctx {
+ struct completion eeprom_load;
+};
+
+#define AR5416_EEPROM_MAGIC 0xa55a
+
+static void ath9k_pci_fixup(struct pci_dev *dev, const u16 *cal_data,
+ size_t cal_len)
+{
+ void __iomem *mem;
+ const void *cal_end = (void *)cal_data + cal_len;
+ const struct {
+ __be16 reg;
+ __be16 low_val;
+ __be16 high_val;
+ } __packed *data;
+ u16 cmd;
+ u32 bar0;
+ bool swap_needed = false;
+
+ if (*cal_data != AR5416_EEPROM_MAGIC) {
+ if (*cal_data != swab16(AR5416_EEPROM_MAGIC)) {
+ pr_err("pci %s: invalid calibration data\n",
+ pci_name(dev));
+ return;
+ }
+ swap_needed = true;
+ }
+
+ pr_info("pci %s: fixup device configuration\n", pci_name(dev));
+
+ mem = pcim_iomap(dev, 0, 0);
+ if (!mem) {
+ pr_err("pci %s: ioremap error\n", pci_name(dev));
+ return;
+ }
+
+ pci_read_config_dword(dev, PCI_BASE_ADDRESS_0, &bar0);
+ pci_write_config_dword(dev, PCI_BASE_ADDRESS_0,
+ pci_resource_start(dev, 0));
+ pci_read_config_word(dev, PCI_COMMAND, &cmd);
+ cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
+ pci_write_config_word(dev, PCI_COMMAND, cmd);
+
+ /* set pointer to first reg address */
+ for (data = (const void *) (cal_data + 3);
+ (const void *) data <= cal_end && data->reg != cpu_to_be16(~0);
+ data++) {
+ u32 val;
+ u16 reg;
+
+ reg = data->reg;
+ val = data->low_val;
+ val |= data->high_val << 16;
+
+ if (swap_needed) {
+ reg = swab16(reg);
+ val = swahb32(val);
+ }
+
+ __raw_writel(val, mem + reg);
+ udelay(100);
+ }
+
+ pci_read_config_word(dev, PCI_COMMAND, &cmd);
+ cmd &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);
+ pci_write_config_word(dev, PCI_COMMAND, cmd);
+
+ pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, bar0);
+ pcim_iounmap(dev, mem);
+
+ pci_disable_device(dev);
+}
+
+static void owl_fw_cb(const struct firmware *fw, void *context)
+{
+ struct pci_dev *pdev = (struct pci_dev *) context;
+ struct owl_ctx *ctx = (struct owl_ctx *) pci_get_drvdata(pdev);
+ struct ath9k_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ struct pci_bus *bus;
+
+ complete(&ctx->eeprom_load);
+
+ if (!fw) {
+ dev_err(&pdev->dev, "no '%s' eeprom file received.",
+ pdata->eeprom_name);
+ goto release;
+ }
+
+ /* also note that we are doing *u16 operations on the file */
+ if (fw->size > sizeof(pdata->eeprom_data) || fw->size < 0x200 ||
+ (fw->size & 1) == 1) {
+ dev_err(&pdev->dev, "eeprom file has an invalid size.");
+ goto release;
+ }
+
+ memcpy(pdata->eeprom_data, fw->data, sizeof(pdata->eeprom_data));
+
+ /* eeprom has been successfully loaded - pass the data to ath9k
+ * but remove the eeprom_name, so it doesn't try to load it too.
+ */
+ pdata->eeprom_name = NULL;
+ ath9k_pci_fixup(pdev, pdata->eeprom_data, fw->size);
+
+ pci_lock_rescan_remove();
+ bus = pdev->bus;
+ pci_stop_and_remove_bus_device(pdev);
+ /* the device should come back with the proper
+ * ProductId. But we have to initiate a rescan.
+ */
+ pci_rescan_bus(bus);
+ pci_unlock_rescan_remove();
+
+release:
+ release_firmware(fw);
+}
+
+static int owl_probe(struct pci_dev *pdev,
+ const struct pci_device_id *id)
+{
+ struct owl_ctx *ctx;
+ struct ath9k_platform_data *pdata;
+ int err = 0;
+
+ if (pcim_enable_device(pdev))
+ return -EIO;
+
+ pcim_pin_device(pdev);
+
+ /* we now have a valid dev->platform_data */
+ pdata = dev_get_platdata(&pdev->dev);
+ if (!pdata) {
+ dev_err(&pdev->dev, "platform data missing.");
+ return -ENODEV;
+ }
+
+ if (!pdata->eeprom_name) {
+ dev_err(&pdev->dev, "no eeprom file defined.");
+ return -ENODEV;
+ }
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx) {
+ dev_err(&pdev->dev, "failed to alloc device context.");
+ return -ENOMEM;
+ }
+ init_completion(&ctx->eeprom_load);
+
+ pci_set_drvdata(pdev, ctx);
+ err = request_firmware_nowait(THIS_MODULE, true, pdata->eeprom_name,
+ &pdev->dev, GFP_KERNEL, pdev, owl_fw_cb);
+ if (err) {
+ dev_err(&pdev->dev, "failed to request caldata (%d).", err);
+ kfree(ctx);
+ }
+ return err;
+}
+
+static void owl_remove(struct pci_dev *pdev)
+{
+ struct owl_ctx *ctx = pci_get_drvdata(pdev);
+
+ if (ctx) {
+ wait_for_completion(&ctx->eeprom_load);
+ pci_set_drvdata(pdev, NULL);
+ kfree(ctx);
+ }
+}
+
+static const struct pci_device_id owl_pci_table[] = {
+ /* PCIe Owl Emulation */
+ { PCI_VDEVICE(ATHEROS, 0xff1c) }, /* PCI-E */
+ { },
+};
+MODULE_DEVICE_TABLE(pci, owl_pci_table);
+
+static struct pci_driver owl_driver = {
+ .name = "owl-loader",
+ .id_table = owl_pci_table,
+ .probe = owl_probe,
+ .remove = owl_remove,
+};
+module_pci_driver(owl_driver);
+MODULE_AUTHOR("Christian Lamparter <chunkeey at googlemail.com>");
+MODULE_DESCRIPTION("Initializes Atheros' Owl Emulation devices");
+MODULE_LICENSE("GPL v2");
--
2.8.0.rc3
_______________________________________________
openwrt-devel mailing list
openwrt-devel at lists.openwrt.org
https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
More information about the openwrt-devel
mailing list