linux/drivers/gpio/gpio-tps6586x.c
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   1/*
   2 * TI TPS6586x GPIO driver
   3 *
   4 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
   5 * Author: Laxman dewangan <ldewangan@nvidia.com>
   6 *
   7 * Based on tps6586x.c
   8 * Copyright (c) 2010 CompuLab Ltd.
   9 * Mike Rapoport <mike@compulab.co.il>
  10 *
  11 * This program is free software; you can redistribute it and/or modify it
  12 * under the terms and conditions of the GNU General Public License,
  13 * version 2, as published by the Free Software Foundation.
  14 *
  15 * This program is distributed in the hope it will be useful, but WITHOUT
  16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  17 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  18 * more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24#include <linux/errno.h>
  25#include <linux/gpio.h>
  26#include <linux/kernel.h>
  27#include <linux/module.h>
  28#include <linux/mfd/tps6586x.h>
  29#include <linux/of_device.h>
  30#include <linux/platform_device.h>
  31
  32/* GPIO control registers */
  33#define TPS6586X_GPIOSET1       0x5d
  34#define TPS6586X_GPIOSET2       0x5e
  35
  36struct tps6586x_gpio {
  37        struct gpio_chip gpio_chip;
  38        struct device *parent;
  39};
  40
  41static inline struct tps6586x_gpio *to_tps6586x_gpio(struct gpio_chip *chip)
  42{
  43        return container_of(chip, struct tps6586x_gpio, gpio_chip);
  44}
  45
  46static int tps6586x_gpio_get(struct gpio_chip *gc, unsigned offset)
  47{
  48        struct tps6586x_gpio *tps6586x_gpio = to_tps6586x_gpio(gc);
  49        uint8_t val;
  50        int ret;
  51
  52        ret = tps6586x_read(tps6586x_gpio->parent, TPS6586X_GPIOSET2, &val);
  53        if (ret)
  54                return ret;
  55
  56        return !!(val & (1 << offset));
  57}
  58
  59static void tps6586x_gpio_set(struct gpio_chip *gc, unsigned offset,
  60                              int value)
  61{
  62        struct tps6586x_gpio *tps6586x_gpio = to_tps6586x_gpio(gc);
  63
  64        tps6586x_update(tps6586x_gpio->parent, TPS6586X_GPIOSET2,
  65                        value << offset, 1 << offset);
  66}
  67
  68static int tps6586x_gpio_output(struct gpio_chip *gc, unsigned offset,
  69                                int value)
  70{
  71        struct tps6586x_gpio *tps6586x_gpio = to_tps6586x_gpio(gc);
  72        uint8_t val, mask;
  73
  74        tps6586x_gpio_set(gc, offset, value);
  75
  76        val = 0x1 << (offset * 2);
  77        mask = 0x3 << (offset * 2);
  78
  79        return tps6586x_update(tps6586x_gpio->parent, TPS6586X_GPIOSET1,
  80                                val, mask);
  81}
  82
  83static int __devinit tps6586x_gpio_probe(struct platform_device *pdev)
  84{
  85        struct tps6586x_platform_data *pdata;
  86        struct tps6586x_gpio *tps6586x_gpio;
  87        int ret;
  88
  89        pdata = dev_get_platdata(pdev->dev.parent);
  90        tps6586x_gpio = devm_kzalloc(&pdev->dev,
  91                                sizeof(*tps6586x_gpio), GFP_KERNEL);
  92        if (!tps6586x_gpio) {
  93                dev_err(&pdev->dev, "Could not allocate tps6586x_gpio\n");
  94                return -ENOMEM;
  95        }
  96
  97        tps6586x_gpio->parent = pdev->dev.parent;
  98
  99        tps6586x_gpio->gpio_chip.owner = THIS_MODULE;
 100        tps6586x_gpio->gpio_chip.label = pdev->name;
 101        tps6586x_gpio->gpio_chip.dev = &pdev->dev;
 102        tps6586x_gpio->gpio_chip.ngpio = 4;
 103        tps6586x_gpio->gpio_chip.can_sleep = 1;
 104
 105        /* FIXME: add handling of GPIOs as dedicated inputs */
 106        tps6586x_gpio->gpio_chip.direction_output = tps6586x_gpio_output;
 107        tps6586x_gpio->gpio_chip.set    = tps6586x_gpio_set;
 108        tps6586x_gpio->gpio_chip.get    = tps6586x_gpio_get;
 109
 110#ifdef CONFIG_OF_GPIO
 111        tps6586x_gpio->gpio_chip.of_node = pdev->dev.parent->of_node;
 112#endif
 113        if (pdata && pdata->gpio_base)
 114                tps6586x_gpio->gpio_chip.base = pdata->gpio_base;
 115        else
 116                tps6586x_gpio->gpio_chip.base = -1;
 117
 118        ret = gpiochip_add(&tps6586x_gpio->gpio_chip);
 119        if (ret < 0) {
 120                dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 121                return ret;
 122        }
 123
 124        platform_set_drvdata(pdev, tps6586x_gpio);
 125
 126        return ret;
 127}
 128
 129static int __devexit tps6586x_gpio_remove(struct platform_device *pdev)
 130{
 131        struct tps6586x_gpio *tps6586x_gpio = platform_get_drvdata(pdev);
 132
 133        return gpiochip_remove(&tps6586x_gpio->gpio_chip);
 134}
 135
 136static struct platform_driver tps6586x_gpio_driver = {
 137        .driver.name    = "tps6586x-gpio",
 138        .driver.owner   = THIS_MODULE,
 139        .probe          = tps6586x_gpio_probe,
 140        .remove         = __devexit_p(tps6586x_gpio_remove),
 141};
 142
 143static int __init tps6586x_gpio_init(void)
 144{
 145        return platform_driver_register(&tps6586x_gpio_driver);
 146}
 147subsys_initcall(tps6586x_gpio_init);
 148
 149static void __exit tps6586x_gpio_exit(void)
 150{
 151        platform_driver_unregister(&tps6586x_gpio_driver);
 152}
 153module_exit(tps6586x_gpio_exit);
 154
 155MODULE_ALIAS("platform:tps6586x-gpio");
 156MODULE_DESCRIPTION("GPIO interface for TPS6586X PMIC");
 157MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 158MODULE_LICENSE("GPL");
 159
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