drivers/gpio/gpio-bd9571mwv.c

   1 /*
   2  * ROHM BD9571MWV-M GPIO driver
   3  *
   4  * Copyright (C) 2017 Marek Vasut <marek.vasut+renesas@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  11  * kind, whether expressed or implied; without even the implied warranty
  12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License version 2 for more details.
  14  *
  15  * Based on the TPS65086 driver
  16  *
  17  * NOTE: Interrupts are not supported yet.
  18  */
  19
  20 #include <linux/gpio/driver.h>
  21 #include <linux/module.h>
  22 #include <linux/platform_device.h>
  23
  24 #include <linux/mfd/bd9571mwv.h>
  25
  26 struct bd9571mwv_gpio {
  27         struct gpio_chip chip;
  28         struct bd9571mwv *bd;
  29 };
  30
  31 static int bd9571mwv_gpio_get_direction(struct gpio_chip *chip,
  32                                        unsigned int offset)
  33 {
  34         struct bd9571mwv_gpio *gpio = gpiochip_get_data(chip);
  35         int ret, val;
  36
  37         ret = regmap_read(gpio->bd->regmap, BD9571MWV_GPIO_DIR, &val);
  38         if (ret < 0)
  39                 return ret;
  40         if (val & BIT(offset))
  41                 return GPIO_LINE_DIRECTION_IN;
  42
  43         return GPIO_LINE_DIRECTION_OUT;
  44 }
  45
  46 static int bd9571mwv_gpio_direction_input(struct gpio_chip *chip,
  47                                          unsigned int offset)
  48 {
  49         struct bd9571mwv_gpio *gpio = gpiochip_get_data(chip);
  50
  51         regmap_update_bits(gpio->bd->regmap, BD9571MWV_GPIO_DIR,
  52                            BIT(offset), 0);
  53
  54         return 0;
  55 }
  56
  57 static int bd9571mwv_gpio_direction_output(struct gpio_chip *chip,
  58                                           unsigned int offset, int value)
  59 {
  60         struct bd9571mwv_gpio *gpio = gpiochip_get_data(chip);
  61
  62         /* Set the initial value */
  63         regmap_update_bits(gpio->bd->regmap, BD9571MWV_GPIO_OUT,
  64                            BIT(offset), value ? BIT(offset) : 0);
  65         regmap_update_bits(gpio->bd->regmap, BD9571MWV_GPIO_DIR,
  66                            BIT(offset), BIT(offset));
  67
  68         return 0;
  69 }
  70
  71 static int bd9571mwv_gpio_get(struct gpio_chip *chip, unsigned int offset)
  72 {
  73         struct bd9571mwv_gpio *gpio = gpiochip_get_data(chip);
  74         int ret, val;
  75
  76         ret = regmap_read(gpio->bd->regmap, BD9571MWV_GPIO_IN, &val);
  77         if (ret < 0)
  78                 return ret;
  79
  80         return val & BIT(offset);
  81 }
  82
  83 static void bd9571mwv_gpio_set(struct gpio_chip *chip, unsigned int offset,
  84                               int value)
  85 {
  86         struct bd9571mwv_gpio *gpio = gpiochip_get_data(chip);
  87
  88         regmap_update_bits(gpio->bd->regmap, BD9571MWV_GPIO_OUT,
  89                            BIT(offset), value ? BIT(offset) : 0);
  90 }
  91
  92 static const struct gpio_chip template_chip = {
  93         .label                  = "bd9571mwv-gpio",
  94         .owner                  = THIS_MODULE,
  95         .get_direction          = bd9571mwv_gpio_get_direction,
  96         .direction_input        = bd9571mwv_gpio_direction_input,
  97         .direction_output       = bd9571mwv_gpio_direction_output,
  98         .get                    = bd9571mwv_gpio_get,
  99         .set                    = bd9571mwv_gpio_set,
 100         .base                   = -1,
 101         .ngpio                  = 2,
 102         .can_sleep              = true,
 103 };
 104
 105 static int bd9571mwv_gpio_probe(struct platform_device *pdev)
 106 {
 107         struct bd9571mwv_gpio *gpio;
 108         int ret;
 109
 110         gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
 111         if (!gpio)
 112                 return -ENOMEM;
 113
 114         platform_set_drvdata(pdev, gpio);
 115
 116         gpio->bd = dev_get_drvdata(pdev->dev.parent);
 117         gpio->chip = template_chip;
 118         gpio->chip.parent = gpio->bd->dev;
 119
 120         ret = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
 121         if (ret < 0) {
 122                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 123                 return ret;
 124         }
 125
 126         return 0;
 127 }
 128
 129 static const struct platform_device_id bd9571mwv_gpio_id_table[] = {
 130         { "bd9571mwv-gpio", },
 131         { /* sentinel */ }
 132 };
 133 MODULE_DEVICE_TABLE(platform, bd9571mwv_gpio_id_table);
 134
 135 static struct platform_driver bd9571mwv_gpio_driver = {
 136         .driver = {
 137                 .name = "bd9571mwv-gpio",
 138         },
 139         .probe = bd9571mwv_gpio_probe,
 140         .id_table = bd9571mwv_gpio_id_table,
 141 };
 142 module_platform_driver(bd9571mwv_gpio_driver);
 143
 144 MODULE_AUTHOR("Marek Vasut <marek.vasut+renesas@gmail.com>");
 145 MODULE_DESCRIPTION("BD9571MWV GPIO driver");
 146 MODULE_LICENSE("GPL v2");