drivers/gpio/gpio-rc5t583.c

   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
  32 struct rc5t583_gpio {
  33         struct gpio_chip gpio_chip;
  34         struct rc5t583 *rc5t583;
  35 };
  36
  37 static int rc5t583_gpio_get(struct gpio_chip *gc, unsigned int offset)
  38 {
  39         struct rc5t583_gpio *rc5t583_gpio = gpiochip_get_data(gc);
  40         struct device *parent = rc5t583_gpio->rc5t583->dev;
  41         uint8_t val = 0;
  42         int ret;
  43
  44         ret = rc5t583_read(parent, RC5T583_GPIO_MON_IOIN, &val);
  45         if (ret < 0)
  46                 return ret;
  47
  48         return !!(val & BIT(offset));
  49 }
  50
  51 static void rc5t583_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
  52 {
  53         struct rc5t583_gpio *rc5t583_gpio = gpiochip_get_data(gc);
  54         struct device *parent = rc5t583_gpio->rc5t583->dev;
  55         if (val)
  56                 rc5t583_set_bits(parent, RC5T583_GPIO_IOOUT, BIT(offset));
  57         else
  58                 rc5t583_clear_bits(parent, RC5T583_GPIO_IOOUT, BIT(offset));
  59 }
  60
  61 static int rc5t583_gpio_dir_input(struct gpio_chip *gc, unsigned int offset)
  62 {
  63         struct rc5t583_gpio *rc5t583_gpio = gpiochip_get_data(gc);
  64         struct device *parent = rc5t583_gpio->rc5t583->dev;
  65         int ret;
  66
  67         ret = rc5t583_clear_bits(parent, RC5T583_GPIO_IOSEL, BIT(offset));
  68         if (ret < 0)
  69                 return ret;
  70
  71         /* Set pin to gpio mode */
  72         return rc5t583_clear_bits(parent, RC5T583_GPIO_PGSEL, BIT(offset));
  73 }
  74
  75 static int rc5t583_gpio_dir_output(struct gpio_chip *gc, unsigned offset,
  76                         int value)
  77 {
  78         struct rc5t583_gpio *rc5t583_gpio = gpiochip_get_data(gc);
  79         struct device *parent = rc5t583_gpio->rc5t583->dev;
  80         int ret;
  81
  82         rc5t583_gpio_set(gc, offset, value);
  83         ret = rc5t583_set_bits(parent, RC5T583_GPIO_IOSEL, BIT(offset));
  84         if (ret < 0)
  85                 return ret;
  86
  87         /* Set pin to gpio mode */
  88         return rc5t583_clear_bits(parent, RC5T583_GPIO_PGSEL, BIT(offset));
  89 }
  90
  91 static int rc5t583_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
  92 {
  93         struct rc5t583_gpio *rc5t583_gpio = gpiochip_get_data(gc);
  94
  95         if (offset < RC5T583_MAX_GPIO)
  96                 return rc5t583_gpio->rc5t583->irq_base +
  97                                 RC5T583_IRQ_GPIO0 + offset;
  98         return -EINVAL;
  99 }
 100
 101 static void rc5t583_gpio_free(struct gpio_chip *gc, unsigned offset)
 102 {
 103         struct rc5t583_gpio *rc5t583_gpio = gpiochip_get_data(gc);
 104         struct device *parent = rc5t583_gpio->rc5t583->dev;
 105
 106         rc5t583_set_bits(parent, RC5T583_GPIO_PGSEL, BIT(offset));
 107 }
 108
 109 static int rc5t583_gpio_probe(struct platform_device *pdev)
 110 {
 111         struct rc5t583 *rc5t583 = dev_get_drvdata(pdev->dev.parent);
 112         struct rc5t583_platform_data *pdata = dev_get_platdata(rc5t583->dev);
 113         struct rc5t583_gpio *rc5t583_gpio;
 114
 115         rc5t583_gpio = devm_kzalloc(&pdev->dev, sizeof(*rc5t583_gpio),
 116                                         GFP_KERNEL);
 117         if (!rc5t583_gpio)
 118                 return -ENOMEM;
 119
 120         rc5t583_gpio->gpio_chip.label = "gpio-rc5t583",
 121         rc5t583_gpio->gpio_chip.owner = THIS_MODULE,
 122         rc5t583_gpio->gpio_chip.free = rc5t583_gpio_free,
 123         rc5t583_gpio->gpio_chip.direction_input = rc5t583_gpio_dir_input,
 124         rc5t583_gpio->gpio_chip.direction_output = rc5t583_gpio_dir_output,
 125         rc5t583_gpio->gpio_chip.set = rc5t583_gpio_set,
 126         rc5t583_gpio->gpio_chip.get = rc5t583_gpio_get,
 127         rc5t583_gpio->gpio_chip.to_irq = rc5t583_gpio_to_irq,
 128         rc5t583_gpio->gpio_chip.ngpio = RC5T583_MAX_GPIO,
 129         rc5t583_gpio->gpio_chip.can_sleep = true,
 130         rc5t583_gpio->gpio_chip.parent = &pdev->dev;
 131         rc5t583_gpio->gpio_chip.base = -1;
 132         rc5t583_gpio->rc5t583 = rc5t583;
 133
 134         if (pdata && pdata->gpio_base)
 135                 rc5t583_gpio->gpio_chip.base = pdata->gpio_base;
 136
 137         platform_set_drvdata(pdev, rc5t583_gpio);
 138
 139         return devm_gpiochip_add_data(&pdev->dev, &rc5t583_gpio->gpio_chip,
 140                                       rc5t583_gpio);
 141 }
 142
 143 static struct platform_driver rc5t583_gpio_driver = {
 144         .driver = {
 145                 .name    = "rc5t583-gpio",
 146         },
 147         .probe          = rc5t583_gpio_probe,
 148 };
 149
 150 static int __init rc5t583_gpio_init(void)
 151 {
 152         return platform_driver_register(&rc5t583_gpio_driver);
 153 }
 154 subsys_initcall(rc5t583_gpio_init);
 155
 156 static void __exit rc5t583_gpio_exit(void)
 157 {
 158         platform_driver_unregister(&rc5t583_gpio_driver);
 159 }
 160 module_exit(rc5t583_gpio_exit);
 161
 162 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 163 MODULE_DESCRIPTION("GPIO interface for RC5T583");
 164 MODULE_LICENSE("GPL v2");
 165 MODULE_ALIAS("platform:rc5t583-gpio");