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 inline struct rc5t583_gpio *to_rc5t583_gpio(struct gpio_chip *chip)
  38 {
  39         return container_of(chip, struct rc5t583_gpio, gpio_chip);
  40 }
  41
  42 static 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
  56 static 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
  66 static 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
  80 static 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
  96 static 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
 106 static 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
 114 static 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 = true,
 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
 149 static 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
 156 static 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
 165 static int __init rc5t583_gpio_init(void)
 166 {
 167         return platform_driver_register(&rc5t583_gpio_driver);
 168 }
 169 subsys_initcall(rc5t583_gpio_init);
 170
 171 static void __exit rc5t583_gpio_exit(void)
 172 {
 173         platform_driver_unregister(&rc5t583_gpio_driver);
 174 }
 175 module_exit(rc5t583_gpio_exit);
 176
 177 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 178 MODULE_DESCRIPTION("GPIO interface for RC5T583");
 179 MODULE_LICENSE("GPL v2");
 180 MODULE_ALIAS("platform:rc5t583-gpio");