[brcm63xx] add 74x164 SPI chip support

Signed-off-by: Miguel Gaio <miguel.gaio@efixo.com>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@23499 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 202 insertions, 24 deletions

diff --git a/target/linux/brcm63xx/patches-2.6.35/211-nxp-74hc164-gpio-chip-driver.patch b/target/linux/brcm63xx/patches-2.6.35/211-gen-74x164-gpio-chip-driver.patch
index db88c1696..105eb6d57 100644
--- a/target/linux/brcm63xx/patches-2.6.35/211-nxp-74hc164-gpio-chip-driver.patch
+++ b/target/linux/brcm63xx/patches-2.6.35/211-gen-74x164-gpio-chip-driver.patch
@@ -1,25 +1,27 @@
 --- a/drivers/gpio/Kconfig
 +++ b/drivers/gpio/Kconfig
-@@ -343,4 +343,12 @@ config GPIO_JANZ_TTL
- 	  This driver provides support for driving the pins in output
- 	  mode only. Input mode is not supported.
+@@ -321,6 +321,14 @@ config GPIO_MC33880
+ 	  SPI driver for Freescale MC33880 high-side/low-side switch.
+ 	  This provides GPIO interface supporting inputs and outputs.
  
-+comment "Other GPIO expanders"
-+
-+config GPIO_NXP_74HC164
-+       tristate "NXP 74HC164 Output expanders"
-+       help
-+         Platform driver for NXP 74HC164 8-output Expanders. This
-+         provides a GPIO interface supporting outputs.
-+
- endif
++config GPIO_74X164
++	tristate "74x164 serial-in/parallel-out 8-bits shift register"
++	depends on SPI_MASTER
++	help
++	  Platform driver for 74x164 compatible serial-in/parallel-out
++	  8-outputs shift registers. This driver can be used to provide access
++	  to more gpio outputs.
++
+ comment "AC97 GPIO expanders:"
+ 
+ config GPIO_UCB1400
 --- a/drivers/gpio/Makefile
 +++ b/drivers/gpio/Makefile
 @@ -17,6 +17,7 @@ obj-$(CONFIG_GPIO_MAX7301)	+= max7301.o
  obj-$(CONFIG_GPIO_MAX732X)	+= max732x.o
  obj-$(CONFIG_GPIO_MC33880)	+= mc33880.o
  obj-$(CONFIG_GPIO_MCP23S08)	+= mcp23s08.o
-+obj-$(CONFIG_GPIO_NXP_74HC164)	+= nxp_74hc164.o
++obj-$(CONFIG_GPIO_74X164)	+= 74x164.o
  obj-$(CONFIG_GPIO_PCA953X)	+= pca953x.o
  obj-$(CONFIG_GPIO_PCF857X)	+= pcf857x.o
  obj-$(CONFIG_GPIO_PL061)	+= pl061.o
@@ -253,27 +255,203 @@
 +MODULE_LICENSE("GPL v2");
 +MODULE_ALIAS("platform:" NXP_74HC164_DRIVER_NAME);
 --- /dev/null
-+++ b/include/linux/nxp_74hc164.h
-@@ -0,0 +1,22 @@
++++ b/drivers/gpio/74x164.c
+@@ -0,0 +1,184 @@
 +/*
-+ *  NXP 74HC164 - Dual 4-input multiplexer defines
++ *  74Hx164 - Generic serial-in/parallel-out 8-bits shift register GPIO driver
 + *
 + *  Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org>
++ *  Copyright (C) 2010 Miguel Gaio <miguel.gaio@efixo.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.
 + */
 +
-+#ifndef _NXP_74HC164_H
-+#define _NXP_74HC164_H
++#include <linux/init.h>
++#include <linux/mutex.h>
++#include <linux/spi/spi.h>
++#include <linux/spi/74x164.h>
++#include <linux/gpio.h>
++#include <linux/slab.h>
++
++#define GEN_74X164_GPIO_COUNT	8
++
++
++struct gen_74x164_chip {
++	struct spi_device	*spi;
++	struct gpio_chip	gpio_chip;
++	struct mutex		lock;
++	u8			port_config;
++};
++
++static void gen_74x164_set_value(struct gpio_chip *, unsigned, int);
++
++static struct gen_74x164_chip *gpio_to_chip(struct gpio_chip *gc)
++{
++	return container_of(gc, struct gen_74x164_chip, gpio_chip);
++}
++
++static int __gen_74x164_write_config(struct gen_74x164_chip *chip)
++{
++	return spi_write(chip->spi,
++			 &chip->port_config, sizeof(chip->port_config));
++}
++
++static int gen_74x164_direction_output(struct gpio_chip *gc,
++		unsigned offset, int val)
++{
++	gen_74x164_set_value(gc, offset, val);
++	return 0;
++}
++
++static int gen_74x164_get_value(struct gpio_chip *gc, unsigned offset)
++{
++	struct gen_74x164_chip *chip = gpio_to_chip(gc);
++	int ret;
++
++	mutex_lock(&chip->lock);
++	ret = (chip->port_config >> offset) & 0x1;
++	mutex_unlock(&chip->lock);
++
++	return ret;
++}
++
++static void gen_74x164_set_value(struct gpio_chip *gc,
++		unsigned offset, int val)
++{
++	struct gen_74x164_chip *chip = gpio_to_chip(gc);
++	bool refresh;
++
++	mutex_lock(&chip->lock);
++	if (val)
++		chip->port_config |= (1 << offset);
++	else
++		chip->port_config &= ~(1 << offset);
++
++	__gen_74x164_write_config(chip);
++	mutex_unlock(&chip->lock);
++}
++
++static int __devinit gen_74x164_probe(struct spi_device *spi)
++{
++	struct gen_74x164_chip *chip;
++	struct gen_74x164_chip_platform_data *pdata;
++	int ret;
++
++	pdata = spi->dev.platform_data;
++	if (!pdata || !pdata->base) {
++		dev_dbg(&spi->dev, "incorrect or missing platform data\n");
++		return -EINVAL;
++	}
++
++	/*
++	 * bits_per_word cannot be configured in platform data
++	 */
++	spi->bits_per_word = 8;
++
++	ret = spi_setup(spi);
++	if (ret < 0)
++		return ret;
++
++	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
++	if (!chip)
++		return -ENOMEM;
++
++	mutex_init(&chip->lock);
++
++	dev_set_drvdata(&spi->dev, chip);
++
++	chip->spi = spi;
++
++	chip->gpio_chip.label = GEN_74X164_DRIVER_NAME,
++		chip->gpio_chip.direction_output = gen_74x164_direction_output;
++	chip->gpio_chip.get = gen_74x164_get_value;
++	chip->gpio_chip.set = gen_74x164_set_value;
++	chip->gpio_chip.base = pdata->base;
++	chip->gpio_chip.ngpio = GEN_74X164_GPIO_COUNT;
++	chip->gpio_chip.can_sleep = 1;
++	chip->gpio_chip.dev = &spi->dev;
++	chip->gpio_chip.owner = THIS_MODULE;
++
++	ret = __gen_74x164_write_config(chip);
++	if (ret) {
++		dev_err(&spi->dev, "Failed writing: %d\n", ret);
++		goto exit_destroy;
++	}
++
++	ret = gpiochip_add(&chip->gpio_chip);
++	if (ret)
++		goto exit_destroy;
++
++	return ret;
++
++exit_destroy:
++	dev_set_drvdata(&spi->dev, NULL);
++	mutex_destroy(&chip->lock);
++	kfree(chip);
++	return ret;
++}
++
++static int gen_74x164_remove(struct spi_device *spi)
++{
++	struct gen_74x164_chip *chip;
++	int ret;
++
++	chip = dev_get_drvdata(&spi->dev);
++	if (chip == NULL)
++		return -ENODEV;
++
++	dev_set_drvdata(&spi->dev, NULL);
++
++	ret = gpiochip_remove(&chip->gpio_chip);
++	if (!ret) {
++		mutex_destroy(&chip->lock);
++		kfree(chip);
++	} else
++		dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n",
++				ret);
++
++	return ret;
++}
++
++static struct spi_driver gen_74x164_driver = {
++	.driver = {
++		.name		= GEN_74X164_DRIVER_NAME,
++		.owner		= THIS_MODULE,
++	},
++	.probe		= gen_74x164_probe,
++	.remove		= __devexit_p(gen_74x164_remove),
++};
++
++static int __init gen_74x164_init(void)
++{
++	return spi_register_driver(&gen_74x164_driver);
++}
++subsys_initcall(gen_74x164_init);
++
++static void __exit gen_74x164_exit(void)
++{
++	spi_unregister_driver(&gen_74x164_driver);
++}
++module_exit(gen_74x164_exit);
++
++MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
++MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
++MODULE_DESCRIPTION("GPIO expander driver for 74X164 8-bits shift register");
++MODULE_LICENSE("GPL v2");
++
+--- /dev/null
++++ b/include/linux/spi/74x164.h
+@@ -0,0 +1,11 @@
++#ifndef LINUX_SPI_74X164_H
++#define LINUX_SPI_74X164_H
 +
-+#define NXP_74HC164_DRIVER_NAME "nxp-74hc164"
++#define GEN_74X164_DRIVER_NAME "74x164"
 +
-+struct nxp_74hc164_platform_data {
-+	unsigned	gpio_base;
-+	unsigned	gpio_pin_data;
-+	unsigned	gpio_pin_clk;
++struct gen_74x164_chip_platform_data {
++	/* number assigned to the first GPIO */
++	unsigned	base;
 +};
 +
-+#endif /* _NXP_74HC164_H */
++#endif