[OpenWrt-Devel] [RFC 2/3] kernel: owl-loader for delayed Atheros ath9k fixup
John Crispin
blogic at openwrt.org
Wed Mar 9 00:05:24 EST 2016
On 09/03/2016 00:14, Christian Lamparter wrote:
> 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.
>
mtd_read() does not work ? i dont see the problem here. ath9k gets
loaded as a ko and at the time when this happens nand is available so
you can just use the normal fw loader mechanism. e do this on most
targets already and there is code to read eeprom data from mtd in other
targets aswell that you can reuse.
John
> Signed-off-by: Christian Lamparter <chunkeey at googlemail.com>
> ---
>
> 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 isn't will not work. 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
> the owl-loader module, since it won't have to deal with any procd/hotplug
> issues.
>
> Note2: Yes, we'll fix the #include "../arch/mips/ath79/pci-ath9k-fixup.h"
> (I think by moving the .h to somewhere in arch/mips/include/...). But first
> we need to know if we can do this via the owl-loader... or not ;-) .
>
> [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 | 55 +++++++++
> package/kernel/owl-loader/src/Makefile | 1 +
> package/kernel/owl-loader/src/owl-loader.c | 133 +++++++++++++++++++++
> .../ar71xx/files/arch/mips/ath79/pci-ath9k-fixup.c | 3 +-
> .../ar71xx/files/arch/mips/ath79/pci-ath9k-fixup.h | 2 +-
> 5 files changed, 192 insertions(+), 2 deletions(-)
> 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..7e62fc5
> --- /dev/null
> +++ b/package/kernel/owl-loader/Makefile
> @@ -0,0 +1,55 @@
> +#
> +# 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 $(INCLUDE_DIR)/package.mk
> +
> +define KernelPackage/owl-loader
> + SUBMENU:=Network Support
> + TITLE:=Owl loader for Atheros PCIe Wifi support
> + DEPENDS:=@PCI_SUPPORT @TARGET_ar71xx +kmod-ath9k
> + FILES:=$(PKG_BUILD_DIR)/owl-loader.ko
> + AUTOLOAD:=$(call AutoProbe,owl-loader)
> + KCONFIG:=
> +endef
> +
> +define KernelPackage/owl-loader/description
> + Kernel module to initialize Owl Emulation Devices.
> + This is necessary for 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..36c638e
> --- /dev/null
> +++ b/package/kernel/owl-loader/src/owl-loader.c
> @@ -0,0 +1,133 @@
> +/*
> + * 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/platform_device.h>
> +#include <linux/ath9k_platform.h>
> +
> +#include "../arch/mips/ath79/pci-ath9k-fixup.h"
> +
> +struct owl_ctx {
> + struct completion eeprom_load;
> +};
> +
> +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;
> + }
> +
> + if (fw->size > sizeof(pdata->eeprom_data)) {
> + dev_err(&pdev->dev, "loaded data is too big.");
> + goto release;
> + }
> +
> + pci_lock_rescan_remove();
> + bus = pdev->bus;
> +
> + 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;
> +
> + pci_enable_ath9k_fixup(0, pdata->eeprom_data);
> + 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;
> +
> + /* we now have a valid dev->platform_data */
> + pdata = dev_get_platdata(&pdev->dev);
> + if (!pdata || !pdata->eeprom_data) {
> + dev_err(&pdev->dev, "platform data missing or 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_LICENSE("GPL");
> diff --git a/target/linux/ar71xx/files/arch/mips/ath79/pci-ath9k-fixup.c b/target/linux/ar71xx/files/arch/mips/ath79/pci-ath9k-fixup.c
> index 2202351..10a7be0 100644
> --- a/target/linux/ar71xx/files/arch/mips/ath79/pci-ath9k-fixup.c
> +++ b/target/linux/ar71xx/files/arch/mips/ath79/pci-ath9k-fixup.c
> @@ -115,7 +115,7 @@ static void ath9k_pci_fixup(struct pci_dev *dev)
> }
> DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_ATHEROS, PCI_ANY_ID, ath9k_pci_fixup);
>
> -void __init pci_enable_ath9k_fixup(unsigned slot, u16 *cal_data)
> +void pci_enable_ath9k_fixup(unsigned slot, u16 *cal_data)
> {
> if (ath9k_num_fixups >= ARRAY_SIZE(ath9k_fixups))
> return;
> @@ -124,3 +124,4 @@ void __init pci_enable_ath9k_fixup(unsigned slot, u16 *cal_data)
> ath9k_fixups[ath9k_num_fixups].cal_data = cal_data;
> ath9k_num_fixups++;
> }
> +EXPORT_SYMBOL_GPL(pci_enable_ath9k_fixup);
> diff --git a/target/linux/ar71xx/files/arch/mips/ath79/pci-ath9k-fixup.h b/target/linux/ar71xx/files/arch/mips/ath79/pci-ath9k-fixup.h
> index 5794941..4f3ad85 100644
> --- a/target/linux/ar71xx/files/arch/mips/ath79/pci-ath9k-fixup.h
> +++ b/target/linux/ar71xx/files/arch/mips/ath79/pci-ath9k-fixup.h
> @@ -1,6 +1,6 @@
> #ifndef _PCI_ATH9K_FIXUP
> #define _PCI_ATH9K_FIXUP
>
> -void pci_enable_ath9k_fixup(unsigned slot, u16 *cal_data) __init;
> +void pci_enable_ath9k_fixup(unsigned slot, u16 *cal_data);
>
> #endif /* _PCI_ATH9K_FIXUP */
>
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