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add 74x164 SPI chip support

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

SVN-Revision: 23499
This commit is contained in:
Florian Fainelli
2010-10-17 14:08:45 +00:00
parent cd9b90235c
commit b65e494976
1 changed files with 201 additions and 23 deletions
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222
target/linux/brcm63xx/patches-2.6.35/211-nxp-74hc164-gpio-chip-driver.patch → target/linux/brcm63xx/patches-2.6.35/211-gen-74x164-gpio-chip-driver.patch
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@@ -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"
+config GPIO_74X164
+ tristate "74x164 serial-in/parallel-out 8-bits shift register"
+ depends on SPI_MASTER
+ help
+ Platform driver for NXP 74HC164 8-output Expanders. This
+ provides a GPIO interface supporting outputs.
+ 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.
+
endif
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 NXP_74HC164_DRIVER_NAME "nxp-74hc164"
+#define GEN_74X164_GPIO_COUNT 8
+
+struct nxp_74hc164_platform_data {
+ unsigned gpio_base;
+ unsigned gpio_pin_data;
+ unsigned gpio_pin_clk;
+
+struct gen_74x164_chip {
+ struct spi_device *spi;
+ struct gpio_chip gpio_chip;
+ struct mutex lock;
+ u8 port_config;
+};
+
+#endif /* _NXP_74HC164_H */
+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