diff options
Diffstat (limited to 'target/linux/ar71xx/files/drivers/gpio/gpio-nxp-74hc153.c')
| -rw-r--r-- | target/linux/ar71xx/files/drivers/gpio/gpio-nxp-74hc153.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/target/linux/ar71xx/files/drivers/gpio/gpio-nxp-74hc153.c b/target/linux/ar71xx/files/drivers/gpio/gpio-nxp-74hc153.c new file mode 100644 index 0000000..a5fec5c --- /dev/null +++ b/target/linux/ar71xx/files/drivers/gpio/gpio-nxp-74hc153.c @@ -0,0 +1,247 @@ +/* + * NXP 74HC153 - Dual 4-input multiplexer GPIO driver + * + * Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org> + * + * 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/module.h> +#include <linux/init.h> +#include <linux/gpio.h> +#include <linux/slab.h> +#include <linux/platform_device.h> +#include <linux/nxp_74hc153.h> + +#define NXP_74HC153_NUM_GPIOS 8 +#define NXP_74HC153_S0_MASK 0x1 +#define NXP_74HC153_S1_MASK 0x2 +#define NXP_74HC153_BANK_MASK 0x4 + +struct nxp_74hc153_chip { + struct device *parent; + struct gpio_chip gpio_chip; + struct mutex lock; +}; + +static struct nxp_74hc153_chip *gpio_to_nxp(struct gpio_chip *gc) +{ + return container_of(gc, struct nxp_74hc153_chip, gpio_chip); +} + +static int nxp_74hc153_direction_input(struct gpio_chip *gc, unsigned offset) +{ + return 0; +} + +static int nxp_74hc153_direction_output(struct gpio_chip *gc, + unsigned offset, int val) +{ + return -EINVAL; +} + +static int nxp_74hc153_get_value(struct gpio_chip *gc, unsigned offset) +{ + struct nxp_74hc153_chip *nxp; + struct nxp_74hc153_platform_data *pdata; + unsigned s0; + unsigned s1; + unsigned pin; + int ret; + + nxp = gpio_to_nxp(gc); + pdata = nxp->parent->platform_data; + + s0 = !!(offset & NXP_74HC153_S0_MASK); + s1 = !!(offset & NXP_74HC153_S1_MASK); + pin = (offset & NXP_74HC153_BANK_MASK) ? pdata->gpio_pin_2y + : pdata->gpio_pin_1y; + + mutex_lock(&nxp->lock); + gpio_set_value(pdata->gpio_pin_s0, s0); + gpio_set_value(pdata->gpio_pin_s1, s1); + ret = gpio_get_value(pin); + mutex_unlock(&nxp->lock); + + return ret; +} + +static void nxp_74hc153_set_value(struct gpio_chip *gc, + unsigned offset, int val) +{ + /* not supported */ +} + +static int __devinit nxp_74hc153_probe(struct platform_device *pdev) +{ + struct nxp_74hc153_platform_data *pdata; + struct nxp_74hc153_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_74hc153_chip), GFP_KERNEL); + if (nxp == NULL) { + dev_err(&pdev->dev, "no memory for private data\n"); + return -ENOMEM; + } + + err = gpio_request(pdata->gpio_pin_s0, dev_name(&pdev->dev)); + if (err) { + dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n", + pdata->gpio_pin_s0, err); + goto err_free_nxp; + } + + err = gpio_request(pdata->gpio_pin_s1, dev_name(&pdev->dev)); + if (err) { + dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n", + pdata->gpio_pin_s1, err); + goto err_free_s0; + } + + err = gpio_request(pdata->gpio_pin_1y, dev_name(&pdev->dev)); + if (err) { + dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n", + pdata->gpio_pin_1y, err); + goto err_free_s1; + } + + err = gpio_request(pdata->gpio_pin_2y, dev_name(&pdev->dev)); + if (err) { + dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n", + pdata->gpio_pin_2y, err); + goto err_free_1y; + } + + err = gpio_direction_output(pdata->gpio_pin_s0, 0); + if (err) { + dev_err(&pdev->dev, + "unable to set direction of gpio %u, err=%d\n", + pdata->gpio_pin_s0, err); + goto err_free_2y; + } + + err = gpio_direction_output(pdata->gpio_pin_s1, 0); + if (err) { + dev_err(&pdev->dev, + "unable to set direction of gpio %u, err=%d\n", + pdata->gpio_pin_s1, err); + goto err_free_2y; + } + + err = gpio_direction_input(pdata->gpio_pin_1y); + if (err) { + dev_err(&pdev->dev, + "unable to set direction of gpio %u, err=%d\n", + pdata->gpio_pin_1y, err); + goto err_free_2y; + } + + err = gpio_direction_input(pdata->gpio_pin_2y); + if (err) { + dev_err(&pdev->dev, + "unable to set direction of gpio %u, err=%d\n", + pdata->gpio_pin_2y, err); + goto err_free_2y; + } + + nxp->parent = &pdev->dev; + mutex_init(&nxp->lock); + + gc = &nxp->gpio_chip; + + gc->direction_input = nxp_74hc153_direction_input; + gc->direction_output = nxp_74hc153_direction_output; + gc->get = nxp_74hc153_get_value; + gc->set = nxp_74hc153_set_value; + gc->can_sleep = 1; + + gc->base = pdata->gpio_base; + gc->ngpio = NXP_74HC153_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_2y; + } + + platform_set_drvdata(pdev, nxp); + return 0; + +err_free_2y: + gpio_free(pdata->gpio_pin_2y); +err_free_1y: + gpio_free(pdata->gpio_pin_1y); +err_free_s1: + gpio_free(pdata->gpio_pin_s1); +err_free_s0: + gpio_free(pdata->gpio_pin_s0); +err_free_nxp: + kfree(nxp); + return err; +} + +static int nxp_74hc153_remove(struct platform_device *pdev) +{ + struct nxp_74hc153_chip *nxp = platform_get_drvdata(pdev); + struct nxp_74hc153_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_2y); + gpio_free(pdata->gpio_pin_1y); + gpio_free(pdata->gpio_pin_s1); + gpio_free(pdata->gpio_pin_s0); + + kfree(nxp); + platform_set_drvdata(pdev, NULL); + } + + return 0; +} + +static struct platform_driver nxp_74hc153_driver = { + .probe = nxp_74hc153_probe, + .remove = __devexit_p(nxp_74hc153_remove), + .driver = { + .name = NXP_74HC153_DRIVER_NAME, + .owner = THIS_MODULE, + }, +}; + +static int __init nxp_74hc153_init(void) +{ + return platform_driver_register(&nxp_74hc153_driver); +} +subsys_initcall(nxp_74hc153_init); + +static void __exit nxp_74hc153_exit(void) +{ + platform_driver_unregister(&nxp_74hc153_driver); +} +module_exit(nxp_74hc153_exit); + +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); +MODULE_DESCRIPTION("GPIO expander driver for NXP 74HC153"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" NXP_74HC153_DRIVER_NAME); |