+--- a/drivers/gpio/Kconfig
++++ b/drivers/gpio/Kconfig
+@@ -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.
+
++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-$(CONFIG_GPIO_74X164) += 74x164.o
+ obj-$(CONFIG_GPIO_PCA953X) += pca953x.o
+ obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o
+ obj-$(CONFIG_GPIO_PL061) += pl061.o
+--- /dev/null
++++ b/drivers/gpio/nxp_74hc164.c
+@@ -0,0 +1,226 @@
++/*
++ * NXP 74HC164 - output expander 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.
++ *
++ * Copy from nxp_74hc153.c code
++ */
++
++#include <linux/module.h>
++#include <linux/init.h>
++#include <linux/gpio.h>
++#include <linux/bitops.h>
++#include <linux/platform_device.h>
++#include <linux/nxp_74hc164.h>
++
++#define NXP_74HC164_NUM_GPIOS 8
++
++struct nxp_74hc164_chip {
++ struct device *parent;
++ struct gpio_chip gpio_chip;
++ struct mutex lock;
++ long mask;
++};
++
++static void nxp_74hc164_set_value(struct gpio_chip *, unsigned, int);
++
++static struct nxp_74hc164_chip *gpio_to_nxp(struct gpio_chip *gc)
++{
++ return container_of(gc, struct nxp_74hc164_chip, gpio_chip);
++}
++
++static int nxp_74hc164_direction_input(struct gpio_chip *gc, unsigned offset)
++{
++ WARN_ON(1);
++ return -EINVAL;
++}
++
++static int nxp_74hc164_direction_output(struct gpio_chip *gc,
++ unsigned offset, int val)
++{
++ nxp_74hc164_set_value(gc, offset, val);
++ return 0;
++}
++
++static int nxp_74hc164_get_value(struct gpio_chip *gc, unsigned offset)
++{
++ struct nxp_74hc164_chip *nxp = gpio_to_nxp(gc);
++ int ret;
++
++ mutex_lock(&nxp->lock);
++ ret = test_bit(offset, &nxp->mask);
++ mutex_unlock(&nxp->lock);
++
++ return ret;
++}
++
++static void nxp_74hc164_set_value(struct gpio_chip *gc,
++ unsigned offset, int val)
++{
++ struct nxp_74hc164_chip *nxp;
++ struct nxp_74hc164_platform_data *pdata;
++ long mask;
++ int refresh;
++ int i;
++
++ nxp = gpio_to_nxp(gc);
++ pdata = nxp->parent->platform_data;
++
++ mutex_lock(&nxp->lock);
++ if (val)
++ refresh = (test_and_set_bit(offset, &nxp->mask) != val);
++ else
++ refresh = (test_and_clear_bit(offset, &nxp->mask) != val);
++
++ if (refresh) {
++ mask = nxp->mask;
++ for (i = 8; i > 0; --i, mask <<= 1) {
++ gpio_set_value(pdata->gpio_pin_data, mask & 0x80);
++ gpio_set_value(pdata->gpio_pin_clk, 1);
++ gpio_set_value(pdata->gpio_pin_clk, 0);
++ }
++ }
++ mutex_unlock(&nxp->lock);
++}
++
++static int __devinit nxp_74hc164_probe(struct platform_device *pdev)
++{
++ struct nxp_74hc164_platform_data *pdata;
++ struct nxp_74hc164_chip *nxp;
++ struct gpio_chip *gc;
++ int err;
++
++ pdata = pdev->dev.platform_data;
++ if (pdata == NULL) {
++ dev_dbg(&pdev->dev, "no platform data specified\n");
++ return -EINVAL;
++ }
++
++ nxp = kzalloc(sizeof(struct nxp_74hc164_chip), GFP_KERNEL);
++ if (nxp == NULL) {
++ dev_err(&pdev->dev, "no memory for private data\n");
++ return -ENOMEM;
++ }
++
++ err = gpio_request(pdata->gpio_pin_clk, dev_name(&pdev->dev));
++ if (err) {
++ dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
++ pdata->gpio_pin_clk, err);
++ goto err_free_nxp;
++ }
++
++ err = gpio_request(pdata->gpio_pin_data, dev_name(&pdev->dev));
++ if (err) {
++ dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
++ pdata->gpio_pin_data, err);
++ goto err_free_clk;
++ }
++
++ err = gpio_direction_output(pdata->gpio_pin_clk, 0);
++ if (err) {
++ dev_err(&pdev->dev,
++ "unable to set direction of gpio %u, err=%d\n",
++ pdata->gpio_pin_clk, err);
++ goto err_free_data;
++ }
++
++ err = gpio_direction_output(pdata->gpio_pin_data, 0);
++ if (err) {
++ dev_err(&pdev->dev,
++ "unable to set direction of gpio %u, err=%d\n",
++ pdata->gpio_pin_data, err);
++ goto err_free_data;
++ }
++
++ nxp->parent = &pdev->dev;
++ mutex_init(&nxp->lock);
++
++ gc = &nxp->gpio_chip;
++
++ gc->direction_input = nxp_74hc164_direction_input;
++ gc->direction_output = nxp_74hc164_direction_output;
++ gc->get = nxp_74hc164_get_value;
++ gc->set = nxp_74hc164_set_value;
++ gc->can_sleep = 1;
++
++ gc->base = pdata->gpio_base;
++ gc->ngpio = NXP_74HC164_NUM_GPIOS;
++ gc->label = dev_name(nxp->parent);
++ gc->dev = nxp->parent;
++ gc->owner = THIS_MODULE;
++
++ err = gpiochip_add(&nxp->gpio_chip);
++ if (err) {
++ dev_err(&pdev->dev, "unable to add gpio chip, err=%d\n", err);
++ goto err_free_data;
++ }
++
++ platform_set_drvdata(pdev, nxp);
++ return 0;
++
++ err_free_data:
++ gpio_free(pdata->gpio_pin_data);
++ err_free_clk:
++ gpio_free(pdata->gpio_pin_clk);
++ err_free_nxp:
++ kfree(nxp);
++ return err;
++}
++
++static int nxp_74hc164_remove(struct platform_device *pdev)
++{
++ struct nxp_74hc164_chip *nxp = platform_get_drvdata(pdev);
++ struct nxp_74hc164_platform_data *pdata = pdev->dev.platform_data;
++
++ if (nxp) {
++ int err;
++
++ err = gpiochip_remove(&nxp->gpio_chip);
++ if (err) {
++ dev_err(&pdev->dev,
++ "unable to remove gpio chip, err=%d\n",
++ err);
++ return err;
++ }
++
++ gpio_free(pdata->gpio_pin_clk);
++ gpio_free(pdata->gpio_pin_data);
++
++ kfree(nxp);
++ platform_set_drvdata(pdev, NULL);
++ }
++
++ return 0;
++}
++
++static struct platform_driver nxp_74hc164_driver = {
++ .probe = nxp_74hc164_probe,
++ .remove = __devexit_p(nxp_74hc164_remove),
++ .driver = {
++ .name = NXP_74HC164_DRIVER_NAME,
++ .owner = THIS_MODULE,
++ },
++};
++
++static int __init nxp_74hc164_init(void)
++{
++ return platform_driver_register(&nxp_74hc164_driver);
++}
++subsys_initcall(nxp_74hc164_init);
++
++static void __exit nxp_74hc164_exit(void)
++{
++ platform_driver_unregister(&nxp_74hc164_driver);
++}
++module_exit(nxp_74hc164_exit);
++
++MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
++MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
++MODULE_DESCRIPTION("GPIO expander driver for NXP 74HC164");
++MODULE_LICENSE("GPL v2");
++MODULE_ALIAS("platform:" NXP_74HC164_DRIVER_NAME);
+--- /dev/null
++++ b/drivers/gpio/74x164.c
+@@ -0,0 +1,184 @@
++/*
++ * 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.
++ */
++
++#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 GEN_74X164_DRIVER_NAME "74x164"
++
++struct gen_74x164_chip_platform_data {
++ /* number assigned to the first GPIO */
++ unsigned base;
++};
++
++#endif
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