diff options
Diffstat (limited to 'drivers/gpio/gpio-74xx-mmio.c')
| -rw-r--r-- | drivers/gpio/gpio-74xx-mmio.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-74xx-mmio.c b/drivers/gpio/gpio-74xx-mmio.c new file mode 100644 index 00000000000..0763655cca6 --- /dev/null +++ b/drivers/gpio/gpio-74xx-mmio.c @@ -0,0 +1,170 @@ +/* + * 74xx MMIO GPIO driver + * + * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/err.h> +#include <linux/gpio.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/basic_mmio_gpio.h> +#include <linux/platform_device.h> + +#define MMIO_74XX_DIR_IN (0 << 8) +#define MMIO_74XX_DIR_OUT (1 << 8) +#define MMIO_74XX_BIT_CNT(x) ((x) & 0xff) + +struct mmio_74xx_gpio_priv { + struct bgpio_chip bgc; + unsigned flags; +}; + +static const struct of_device_id mmio_74xx_gpio_ids[] = { + { + .compatible = "ti,741g125", + .data = (const void *)(MMIO_74XX_DIR_IN | 1), + }, + { + .compatible = "ti,742g125", + .data = (const void *)(MMIO_74XX_DIR_IN | 2), + }, + { + .compatible = "ti,74125", + .data = (const void *)(MMIO_74XX_DIR_IN | 4), + }, + { + .compatible = "ti,74365", + .data = (const void *)(MMIO_74XX_DIR_IN | 6), + }, + { + .compatible = "ti,74244", + .data = (const void *)(MMIO_74XX_DIR_IN | 8), + }, + { + .compatible = "ti,741624", + .data = (const void *)(MMIO_74XX_DIR_IN | 16), + }, + { + .compatible = "ti,741g74", + .data = (const void *)(MMIO_74XX_DIR_OUT | 1), + }, + { + .compatible = "ti,7474", + .data = (const void *)(MMIO_74XX_DIR_OUT | 2), + }, + { + .compatible = "ti,74175", + .data = (const void *)(MMIO_74XX_DIR_OUT | 4), + }, + { + .compatible = "ti,74174", + .data = (const void *)(MMIO_74XX_DIR_OUT | 6), + }, + { + .compatible = "ti,74273", + .data = (const void *)(MMIO_74XX_DIR_OUT | 8), + }, + { + .compatible = "ti,7416374", + .data = (const void *)(MMIO_74XX_DIR_OUT | 16), + }, + { } +}; +MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids); + +static inline struct mmio_74xx_gpio_priv *to_74xx_gpio(struct gpio_chip *gc) +{ + struct bgpio_chip *bgc = to_bgpio_chip(gc); + + return container_of(bgc, struct mmio_74xx_gpio_priv, bgc); +} + +static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset) +{ + struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc); + + return (priv->flags & MMIO_74XX_DIR_OUT) ? GPIOF_DIR_OUT : GPIOF_DIR_IN; +} + +static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio) +{ + struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc); + + return (priv->flags & MMIO_74XX_DIR_OUT) ? -ENOTSUPP : 0; +} + +static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) +{ + struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc); + + if (priv->flags & MMIO_74XX_DIR_OUT) { + gc->set(gc, gpio, val); + return 0; + } + + return -ENOTSUPP; +} + +static int mmio_74xx_gpio_probe(struct platform_device *pdev) +{ + const struct of_device_id *of_id = + of_match_device(mmio_74xx_gpio_ids, &pdev->dev); + struct mmio_74xx_gpio_priv *priv; + struct resource *res; + void __iomem *dat; + int err; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dat = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(dat)) + return PTR_ERR(dat); + + priv->flags = (unsigned)of_id->data; + + err = bgpio_init(&priv->bgc, &pdev->dev, + DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8), + dat, NULL, NULL, NULL, NULL, 0); + if (err) + return err; + + priv->bgc.gc.direction_input = mmio_74xx_dir_in; + priv->bgc.gc.direction_output = mmio_74xx_dir_out; + priv->bgc.gc.get_direction = mmio_74xx_get_direction; + priv->bgc.gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags); + priv->bgc.gc.owner = THIS_MODULE; + + platform_set_drvdata(pdev, priv); + + return gpiochip_add(&priv->bgc.gc); +} + +static int mmio_74xx_gpio_remove(struct platform_device *pdev) +{ + struct mmio_74xx_gpio_priv *priv = platform_get_drvdata(pdev); + + return bgpio_remove(&priv->bgc); +} + +static struct platform_driver mmio_74xx_gpio_driver = { + .driver = { + .name = "74xx-mmio-gpio", + .of_match_table = mmio_74xx_gpio_ids, + }, + .probe = mmio_74xx_gpio_probe, + .remove = mmio_74xx_gpio_remove, +}; +module_platform_driver(mmio_74xx_gpio_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); +MODULE_DESCRIPTION("74xx MMIO GPIO driver"); |