linux/drivers/gpio/gpio-palmas.c
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   1/*
   2 * TI Palma series PMIC's GPIO driver.
   3 *
   4 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
   5 *
   6 * Author: Laxman Dewangan <ldewangan@nvidia.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify it
   9 * under the terms and conditions of the GNU General Public License,
  10 * version 2, as published by the Free Software Foundation.
  11 *
  12 * This program is distributed in the hope it will be useful, but WITHOUT
  13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15 * more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21#include <linux/gpio.h>
  22#include <linux/kernel.h>
  23#include <linux/module.h>
  24#include <linux/mfd/palmas.h>
  25#include <linux/of.h>
  26#include <linux/of_device.h>
  27#include <linux/platform_device.h>
  28
  29struct palmas_gpio {
  30        struct gpio_chip gpio_chip;
  31        struct palmas *palmas;
  32};
  33
  34static inline struct palmas_gpio *to_palmas_gpio(struct gpio_chip *chip)
  35{
  36        return container_of(chip, struct palmas_gpio, gpio_chip);
  37}
  38
  39static int palmas_gpio_get(struct gpio_chip *gc, unsigned offset)
  40{
  41        struct palmas_gpio *pg = to_palmas_gpio(gc);
  42        struct palmas *palmas = pg->palmas;
  43        unsigned int val;
  44        int ret;
  45
  46        ret = palmas_read(palmas, PALMAS_GPIO_BASE, PALMAS_GPIO_DATA_IN, &val);
  47        if (ret < 0) {
  48                dev_err(gc->dev, "GPIO_DATA_IN read failed, err = %d\n", ret);
  49                return ret;
  50        }
  51        return !!(val & BIT(offset));
  52}
  53
  54static void palmas_gpio_set(struct gpio_chip *gc, unsigned offset,
  55                        int value)
  56{
  57        struct palmas_gpio *pg = to_palmas_gpio(gc);
  58        struct palmas *palmas = pg->palmas;
  59        int ret;
  60
  61        if (value)
  62                ret = palmas_write(palmas, PALMAS_GPIO_BASE,
  63                                PALMAS_GPIO_SET_DATA_OUT, BIT(offset));
  64        else
  65                ret = palmas_write(palmas, PALMAS_GPIO_BASE,
  66                                PALMAS_GPIO_CLEAR_DATA_OUT, BIT(offset));
  67        if (ret < 0)
  68                dev_err(gc->dev, "%s write failed, err = %d\n",
  69                        (value) ? "GPIO_SET_DATA_OUT" : "GPIO_CLEAR_DATA_OUT",
  70                        ret);
  71}
  72
  73static int palmas_gpio_output(struct gpio_chip *gc, unsigned offset,
  74                                int value)
  75{
  76        struct palmas_gpio *pg = to_palmas_gpio(gc);
  77        struct palmas *palmas = pg->palmas;
  78        int ret;
  79
  80        /* Set the initial value */
  81        palmas_gpio_set(gc, offset, value);
  82
  83        ret = palmas_update_bits(palmas, PALMAS_GPIO_BASE,
  84                PALMAS_GPIO_DATA_DIR, BIT(offset), BIT(offset));
  85        if (ret < 0)
  86                dev_err(gc->dev, "GPIO_DATA_DIR write failed, err = %d\n", ret);
  87        return ret;
  88}
  89
  90static int palmas_gpio_input(struct gpio_chip *gc, unsigned offset)
  91{
  92        struct palmas_gpio *pg = to_palmas_gpio(gc);
  93        struct palmas *palmas = pg->palmas;
  94        int ret;
  95
  96        ret = palmas_update_bits(palmas, PALMAS_GPIO_BASE,
  97                PALMAS_GPIO_DATA_DIR, BIT(offset), 0);
  98        if (ret < 0)
  99                dev_err(gc->dev, "GPIO_DATA_DIR write failed, err = %d\n", ret);
 100        return ret;
 101}
 102
 103static int palmas_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
 104{
 105        struct palmas_gpio *pg = to_palmas_gpio(gc);
 106        struct palmas *palmas = pg->palmas;
 107
 108        return palmas_irq_get_virq(palmas, PALMAS_GPIO_0_IRQ + offset);
 109}
 110
 111static int palmas_gpio_probe(struct platform_device *pdev)
 112{
 113        struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
 114        struct palmas_platform_data *palmas_pdata;
 115        struct palmas_gpio *palmas_gpio;
 116        int ret;
 117
 118        palmas_gpio = devm_kzalloc(&pdev->dev,
 119                                sizeof(*palmas_gpio), GFP_KERNEL);
 120        if (!palmas_gpio) {
 121                dev_err(&pdev->dev, "Could not allocate palmas_gpio\n");
 122                return -ENOMEM;
 123        }
 124
 125        palmas_gpio->palmas = palmas;
 126        palmas_gpio->gpio_chip.owner = THIS_MODULE;
 127        palmas_gpio->gpio_chip.label = dev_name(&pdev->dev);
 128        palmas_gpio->gpio_chip.ngpio = 8;
 129        palmas_gpio->gpio_chip.can_sleep = 1;
 130        palmas_gpio->gpio_chip.direction_input = palmas_gpio_input;
 131        palmas_gpio->gpio_chip.direction_output = palmas_gpio_output;
 132        palmas_gpio->gpio_chip.to_irq = palmas_gpio_to_irq;
 133        palmas_gpio->gpio_chip.set      = palmas_gpio_set;
 134        palmas_gpio->gpio_chip.get      = palmas_gpio_get;
 135        palmas_gpio->gpio_chip.dev = &pdev->dev;
 136#ifdef CONFIG_OF_GPIO
 137        palmas_gpio->gpio_chip.of_node = palmas->dev->of_node;
 138#endif
 139        palmas_pdata = dev_get_platdata(palmas->dev);
 140        if (palmas_pdata && palmas_pdata->gpio_base)
 141                palmas_gpio->gpio_chip.base = palmas_pdata->gpio_base;
 142        else
 143                palmas_gpio->gpio_chip.base = -1;
 144
 145        ret = gpiochip_add(&palmas_gpio->gpio_chip);
 146        if (ret < 0) {
 147                dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 148                return ret;
 149        }
 150
 151        platform_set_drvdata(pdev, palmas_gpio);
 152        return ret;
 153}
 154
 155static int palmas_gpio_remove(struct platform_device *pdev)
 156{
 157        struct palmas_gpio *palmas_gpio = platform_get_drvdata(pdev);
 158
 159        return gpiochip_remove(&palmas_gpio->gpio_chip);
 160}
 161
 162static struct platform_driver palmas_gpio_driver = {
 163        .driver.name    = "palmas-gpio",
 164        .driver.owner   = THIS_MODULE,
 165        .probe          = palmas_gpio_probe,
 166        .remove         = palmas_gpio_remove,
 167};
 168
 169static int __init palmas_gpio_init(void)
 170{
 171        return platform_driver_register(&palmas_gpio_driver);
 172}
 173subsys_initcall(palmas_gpio_init);
 174
 175static void __exit palmas_gpio_exit(void)
 176{
 177        platform_driver_unregister(&palmas_gpio_driver);
 178}
 179module_exit(palmas_gpio_exit);
 180
 181MODULE_ALIAS("platform:palmas-gpio");
 182MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 183MODULE_DESCRIPTION("GPIO driver for TI Palmas series PMICs");
 184MODULE_LICENSE("GPL v2");
 185
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