linux/drivers/gpio/gpio-rc5t583.c
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   1/*
   2 * GPIO driver for RICOH583 power management chip.
   3 *
   4 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
   5 * Author: Laxman dewangan <ldewangan@nvidia.com>
   6 *
   7 * Based on code
   8 *      Copyright (C) 2011 RICOH COMPANY,LTD
   9 *
  10 * This program is free software; you can redistribute it and/or modify it
  11 * under the terms and conditions of the GNU General Public License,
  12 * version 2, as published by the Free Software Foundation.
  13 *
  14 * This program is distributed in the hope it will be useful, but WITHOUT
  15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  17 * more details.
  18 *
  19 * You should have received a copy of the GNU General Public License
  20 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 *
  22 */
  23#include <linux/init.h>
  24#include <linux/kernel.h>
  25#include <linux/slab.h>
  26#include <linux/module.h>
  27#include <linux/platform_device.h>
  28#include <linux/device.h>
  29#include <linux/gpio.h>
  30#include <linux/mfd/rc5t583.h>
  31
  32struct rc5t583_gpio {
  33        struct gpio_chip gpio_chip;
  34        struct rc5t583 *rc5t583;
  35};
  36
  37static inline struct rc5t583_gpio *to_rc5t583_gpio(struct gpio_chip *chip)
  38{
  39        return container_of(chip, struct rc5t583_gpio, gpio_chip);
  40}
  41
  42static int rc5t583_gpio_get(struct gpio_chip *gc, unsigned int offset)
  43{
  44        struct rc5t583_gpio *rc5t583_gpio = to_rc5t583_gpio(gc);
  45        struct device *parent = rc5t583_gpio->rc5t583->dev;
  46        uint8_t val = 0;
  47        int ret;
  48
  49        ret = rc5t583_read(parent, RC5T583_GPIO_MON_IOIN, &val);
  50        if (ret < 0)
  51                return ret;
  52
  53        return !!(val & BIT(offset));
  54}
  55
  56static void rc5t583_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
  57{
  58        struct rc5t583_gpio *rc5t583_gpio = to_rc5t583_gpio(gc);
  59        struct device *parent = rc5t583_gpio->rc5t583->dev;
  60        if (val)
  61                rc5t583_set_bits(parent, RC5T583_GPIO_IOOUT, BIT(offset));
  62        else
  63                rc5t583_clear_bits(parent, RC5T583_GPIO_IOOUT, BIT(offset));
  64}
  65
  66static int rc5t583_gpio_dir_input(struct gpio_chip *gc, unsigned int offset)
  67{
  68        struct rc5t583_gpio *rc5t583_gpio = to_rc5t583_gpio(gc);
  69        struct device *parent = rc5t583_gpio->rc5t583->dev;
  70        int ret;
  71
  72        ret = rc5t583_clear_bits(parent, RC5T583_GPIO_IOSEL, BIT(offset));
  73        if (ret < 0)
  74                return ret;
  75
  76        /* Set pin to gpio mode */
  77        return rc5t583_clear_bits(parent, RC5T583_GPIO_PGSEL, BIT(offset));
  78}
  79
  80static int rc5t583_gpio_dir_output(struct gpio_chip *gc, unsigned offset,
  81                        int value)
  82{
  83        struct rc5t583_gpio *rc5t583_gpio = to_rc5t583_gpio(gc);
  84        struct device *parent = rc5t583_gpio->rc5t583->dev;
  85        int ret;
  86
  87        rc5t583_gpio_set(gc, offset, value);
  88        ret = rc5t583_set_bits(parent, RC5T583_GPIO_IOSEL, BIT(offset));
  89        if (ret < 0)
  90                return ret;
  91
  92        /* Set pin to gpio mode */
  93        return rc5t583_clear_bits(parent, RC5T583_GPIO_PGSEL, BIT(offset));
  94}
  95
  96static int rc5t583_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
  97{
  98        struct rc5t583_gpio *rc5t583_gpio = to_rc5t583_gpio(gc);
  99
 100        if ((offset >= 0) && (offset < 8))
 101                return rc5t583_gpio->rc5t583->irq_base +
 102                                RC5T583_IRQ_GPIO0 + offset;
 103        return -EINVAL;
 104}
 105
 106static void rc5t583_gpio_free(struct gpio_chip *gc, unsigned offset)
 107{
 108        struct rc5t583_gpio *rc5t583_gpio = to_rc5t583_gpio(gc);
 109        struct device *parent = rc5t583_gpio->rc5t583->dev;
 110
 111        rc5t583_set_bits(parent, RC5T583_GPIO_PGSEL, BIT(offset));
 112}
 113
 114static int rc5t583_gpio_probe(struct platform_device *pdev)
 115{
 116        struct rc5t583 *rc5t583 = dev_get_drvdata(pdev->dev.parent);
 117        struct rc5t583_platform_data *pdata = dev_get_platdata(rc5t583->dev);
 118        struct rc5t583_gpio *rc5t583_gpio;
 119
 120        rc5t583_gpio = devm_kzalloc(&pdev->dev, sizeof(*rc5t583_gpio),
 121                                        GFP_KERNEL);
 122        if (!rc5t583_gpio) {
 123                dev_warn(&pdev->dev, "Mem allocation for rc5t583_gpio failed");
 124                return -ENOMEM;
 125        }
 126
 127        rc5t583_gpio->gpio_chip.label = "gpio-rc5t583",
 128        rc5t583_gpio->gpio_chip.owner = THIS_MODULE,
 129        rc5t583_gpio->gpio_chip.free = rc5t583_gpio_free,
 130        rc5t583_gpio->gpio_chip.direction_input = rc5t583_gpio_dir_input,
 131        rc5t583_gpio->gpio_chip.direction_output = rc5t583_gpio_dir_output,
 132        rc5t583_gpio->gpio_chip.set = rc5t583_gpio_set,
 133        rc5t583_gpio->gpio_chip.get = rc5t583_gpio_get,
 134        rc5t583_gpio->gpio_chip.to_irq = rc5t583_gpio_to_irq,
 135        rc5t583_gpio->gpio_chip.ngpio = RC5T583_MAX_GPIO,
 136        rc5t583_gpio->gpio_chip.can_sleep = 1,
 137        rc5t583_gpio->gpio_chip.dev = &pdev->dev;
 138        rc5t583_gpio->gpio_chip.base = -1;
 139        rc5t583_gpio->rc5t583 = rc5t583;
 140
 141        if (pdata && pdata->gpio_base)
 142                rc5t583_gpio->gpio_chip.base = pdata->gpio_base;
 143
 144        platform_set_drvdata(pdev, rc5t583_gpio);
 145
 146        return gpiochip_add(&rc5t583_gpio->gpio_chip);
 147}
 148
 149static int rc5t583_gpio_remove(struct platform_device *pdev)
 150{
 151        struct rc5t583_gpio *rc5t583_gpio = platform_get_drvdata(pdev);
 152
 153        return gpiochip_remove(&rc5t583_gpio->gpio_chip);
 154}
 155
 156static struct platform_driver rc5t583_gpio_driver = {
 157        .driver = {
 158                .name    = "rc5t583-gpio",
 159                .owner   = THIS_MODULE,
 160        },
 161        .probe          = rc5t583_gpio_probe,
 162        .remove         = rc5t583_gpio_remove,
 163};
 164
 165static int __init rc5t583_gpio_init(void)
 166{
 167        return platform_driver_register(&rc5t583_gpio_driver);
 168}
 169subsys_initcall(rc5t583_gpio_init);
 170
 171static void __exit rc5t583_gpio_exit(void)
 172{
 173        platform_driver_unregister(&rc5t583_gpio_driver);
 174}
 175module_exit(rc5t583_gpio_exit);
 176
 177MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 178MODULE_DESCRIPTION("GPIO interface for RC5T583");
 179MODULE_LICENSE("GPL v2");
 180MODULE_ALIAS("platform:rc5t583-gpio");
 181
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