--- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -230,4 +230,12 @@ config GPIO_UCB1400 To compile this driver as a module, choose M here: the module will be called ucb1400_gpio. +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 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -10,6 +10,7 @@ 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_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 + * Copyright (C) 2010 Miguel Gaio + * + * 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 +#include +#include +#include +#include +#include + +#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 "); +MODULE_AUTHOR("Miguel Gaio "); +MODULE_DESCRIPTION("GPIO expander driver for NXP 74HC164"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" NXP_74HC164_DRIVER_NAME); --- /dev/null +++ b/include/linux/nxp_74hc164.h @@ -0,0 +1,22 @@ +/* + * NXP 74HC164 - Dual 4-input multiplexer defines + * + * Copyright (C) 2010 Gabor Juhos + * + * 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 + +#define NXP_74HC164_DRIVER_NAME "nxp-74hc164" + +struct nxp_74hc164_platform_data { + unsigned gpio_base; + unsigned gpio_pin_data; + unsigned gpio_pin_clk; +}; + +#endif /* _NXP_74HC164_H */