[LEDE-DEV] [PATCH 2/3] kernel: owl-loader for delayed Atheros ath9k fixup

Christian Lamparter chunkeey at googlemail.com
Thu Sep 8 14:58:46 PDT 2016


Hello,

On Thursday, September 8, 2016 9:34:07 AM CEST John Crispin wrote:
> Hi,
> 
> why is this code located under package/ and not as a kernel patch under
> target/linux/generic ?

well, there isn't a good reason. In fact, it started as a copy of
gpio-button-hotplug's skeleton and evolved it from there into
owl-loader.

So yes, if it needs to go in a different location, that would be fine.
Based on your suggestion, I think the owl-loader.c code can be moved to:
target/linux/generic/files/drivers/net/wireless/ath9k/owl-loader.c

and the module definition from the Makefile can be copied into:
package/kernel/linux/modules/wireless.mk

Or do you have something else in mind?

Regards,
Christian
 
> On 05/09/2016 06:59, Chris Blake wrote:
> > From: Christian Lamparter <chunkeey at googlemail.com>
> > 
> > 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.
> > 
> > Martin Blumenstingl made a few fixes and added support for lantiq:
> > kernel: owl-loader: add support for OWL emulation PCI devices
> > kernel: owl-loader: don't re-scan the bus when ath9k_pci_fixup failed
> > kernel: owl-loader: use dev_* instead of pr_* logging functions
> > kernel: owl-loader: auto-generate the eeprom filename as fallback
> > kernel: owl-loader: add a debug message when swapping the eeprom data
> > kernel: owl-loader: add missing newlines in log messages
> > kernel: owl-loader: add support for the lantiq platform
> > 
> > These patches have been integrated. Thanks!
> > 
> > Signed-off-by: Martin Blumenstingl <martin.blumenstingl at googlemail.com>
> > Signed-off-by: Christian Lamparter <chunkeey at googlemail.com>
> > ---
> >  package/kernel/owl-loader/Makefile         |  59 +++++++
> >  package/kernel/owl-loader/src/Makefile     |   1 +
> >  package/kernel/owl-loader/src/owl-loader.c | 246 +++++++++++++++++++++++++++++
> >  3 files changed, 306 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..b6c58de
> > --- /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 $(INCLUDE_DIR)/package.mk
> > +
> > +define KernelPackage/owl-loader
> > +  SUBMENU:=Network Support
> > +  TITLE:=Owl loader for initializing Atheros PCI(e) Wifi chips
> > +  DEPENDS:=@PCI_SUPPORT +kmod-ath9k
> > +  FILES:=$(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' PCI(e) Wifi chips, which have the init data
> > +  (which contains the PCI device ID for example) 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..30340da
> > --- /dev/null
> > +++ b/package/kernel/owl-loader/src/owl-loader.c
> > @@ -0,0 +1,246 @@
> > +/*
> > + * Initialize Owl Emulation Devices
> > + *
> > + * Copyright (C) 2016 Christian Lamparter <chunkeey at googlemail.com>
> > + * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl 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/etherdevice.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 EEPROM_FILENAME_LEN 100
> > +
> > +#define AR5416_EEPROM_MAGIC 0xa55a
> > +
> > +static int ath9k_pci_fixup(struct pci_dev *pdev, 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)) {
> > +			dev_err(&pdev->dev, "invalid calibration data\n");
> > +			return -EINVAL;
> > +		}
> > +
> > +		dev_dbg(&pdev->dev, "calibration data needs swapping\n");
> > +		swap_needed = true;
> > +	}
> > +
> > +	dev_info(&pdev->dev, "fixup device configuration\n");
> > +
> > +	mem = pcim_iomap(pdev, 0, 0);
> > +	if (!mem) {
> > +		dev_err(&pdev->dev, "ioremap error\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	pci_read_config_dword(pdev, PCI_BASE_ADDRESS_0, &bar0);
> > +	pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0,
> > +			       pci_resource_start(pdev, 0));
> > +	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
> > +	cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
> > +	pci_write_config_word(pdev, 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);
> > +		}
> > +
> > +#if CONFIG_LANTIQ
> > +		val = swab32(val);
> > +#endif
> > +
> > +		__raw_writel(val, mem + reg);
> > +		udelay(100);
> > +	}
> > +
> > +	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
> > +	cmd &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);
> > +	pci_write_config_word(pdev, PCI_COMMAND, cmd);
> > +
> > +	pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0, bar0);
> > +	pcim_iounmap(pdev, mem);
> > +
> > +	pci_disable_device(pdev);
> > +
> > +	return 0;
> > +}
> > +
> > +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 eeprom data received.\n");
> > +		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.\n");
> > +		goto release;
> > +	}
> > +
> > +	if (pdata) {
> > +		memcpy(pdata->eeprom_data, fw->data, fw->size);
> > +
> > +		/*
> > +		 * 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;
> > +	}
> > +
> > +	if (ath9k_pci_fixup(pdev, (const u16 *) fw->data, fw->size))
> > +		goto release;
> > +
> > +	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 const char *owl_get_eeprom_name(struct pci_dev *pdev)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	struct ath9k_platform_data *pdata;
> > +	char *eeprom_name;
> > +
> > +	/* try the existing platform data first */
> > +	pdata = dev_get_platdata(dev);
> > +	if (pdata && pdata->eeprom_name)
> > +		return pdata->eeprom_name;
> > +
> > +	dev_dbg(dev, "using auto-generated eeprom filename\n");
> > +
> > +	eeprom_name = devm_kzalloc(dev, EEPROM_FILENAME_LEN, GFP_KERNEL);
> > +	if (!eeprom_name)
> > +		return NULL;
> > +
> > +	/* this should match the pattern used in ath9k/init.c */
> > +	scnprintf(eeprom_name, EEPROM_FILENAME_LEN, "ath9k-eeprom-pci-%s.bin",
> > +		  dev_name(dev));
> > +
> > +	return eeprom_name;
> > +}
> > +
> > +static int owl_probe(struct pci_dev *pdev,
> > +		    const struct pci_device_id *id)
> > +{
> > +	struct owl_ctx *ctx;
> > +	const char *eeprom_name;
> > +	int err = 0;
> > +
> > +	if (pcim_enable_device(pdev))
> > +		return -EIO;
> > +
> > +	pcim_pin_device(pdev);
> > +
> > +	eeprom_name = owl_get_eeprom_name(pdev);
> > +	if (!eeprom_name) {
> > +		dev_err(&pdev->dev, "no eeprom filename found.\n");
> > +		return -ENODEV;
> > +	}
> > +
> > +	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
> > +	if (!ctx) {
> > +		dev_err(&pdev->dev, "failed to alloc device context.\n");
> > +		return -ENOMEM;
> > +	}
> > +	init_completion(&ctx->eeprom_load);
> > +
> > +	pci_set_drvdata(pdev, ctx);
> > +	err = request_firmware_nowait(THIS_MODULE, true, eeprom_name,
> > +				      &pdev->dev, GFP_KERNEL, pdev, owl_fw_cb);
> > +	if (err) {
> > +		dev_err(&pdev->dev, "failed to request caldata (%d).\n", 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[] = {
> > +	{ PCI_VDEVICE(ATHEROS, 0xff1c) }, /* PCIe */
> > +	{ PCI_VDEVICE(ATHEROS, 0xff1d) }, /* PCI */
> > +	{ },
> > +};
> > +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");
> > 
> 





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