drivers/gpio/gpio-lp873x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
   4  *      Keerthy <j-keerthy@ti.com>
   5  *
   6  * Based on the TPS65218 driver
   7  */
   8
   9 #include <linux/gpio/driver.h>
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/regmap.h>
  13
  14 #include <linux/mfd/lp873x.h>
  15
  16 #define BITS_PER_GPO            0x4
  17 #define LP873X_GPO_CTRL_OD      0x2
  18
  19 struct lp873x_gpio {
  20         struct gpio_chip chip;
  21         struct lp873x *lp873;
  22 };
  23
  24 static int lp873x_gpio_get_direction(struct gpio_chip *chip,
  25                                      unsigned int offset)
  26 {
  27         /* This device is output only */
  28         return GPIO_LINE_DIRECTION_OUT;
  29 }
  30
  31 static int lp873x_gpio_direction_input(struct gpio_chip *chip,
  32                                        unsigned int offset)
  33 {
  34         /* This device is output only */
  35         return -EINVAL;
  36 }
  37
  38 static int lp873x_gpio_direction_output(struct gpio_chip *chip,
  39                                         unsigned int offset, int value)
  40 {
  41         struct lp873x_gpio *gpio = gpiochip_get_data(chip);
  42
  43         /* Set the initial value */
  44         return regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
  45                                   BIT(offset * BITS_PER_GPO),
  46                                   value ? BIT(offset * BITS_PER_GPO) : 0);
  47 }
  48
  49 static int lp873x_gpio_get(struct gpio_chip *chip, unsigned int offset)
  50 {
  51         struct lp873x_gpio *gpio = gpiochip_get_data(chip);
  52         int ret, val;
  53
  54         ret = regmap_read(gpio->lp873->regmap, LP873X_REG_GPO_CTRL, &val);
  55         if (ret < 0)
  56                 return ret;
  57
  58         return val & BIT(offset * BITS_PER_GPO);
  59 }
  60
  61 static void lp873x_gpio_set(struct gpio_chip *chip, unsigned int offset,
  62                             int value)
  63 {
  64         struct lp873x_gpio *gpio = gpiochip_get_data(chip);
  65
  66         regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
  67                            BIT(offset * BITS_PER_GPO),
  68                            value ? BIT(offset * BITS_PER_GPO) : 0);
  69 }
  70
  71 static int lp873x_gpio_request(struct gpio_chip *gc, unsigned int offset)
  72 {
  73         struct lp873x_gpio *gpio = gpiochip_get_data(gc);
  74         int ret;
  75
  76         switch (offset) {
  77         case 0:
  78                 /* No MUX Set up Needed for GPO */
  79                 break;
  80         case 1:
  81                 /* Setup the CLKIN_PIN_SEL MUX to GPO2 */
  82                 ret = regmap_update_bits(gpio->lp873->regmap, LP873X_REG_CONFIG,
  83                                          LP873X_CONFIG_CLKIN_PIN_SEL, 0);
  84                 if (ret)
  85                         return ret;
  86
  87                 break;
  88         default:
  89                 return -EINVAL;
  90         }
  91
  92         return 0;
  93 }
  94
  95 static int lp873x_gpio_set_config(struct gpio_chip *gc, unsigned offset,
  96                                   unsigned long config)
  97 {
  98         struct lp873x_gpio *gpio = gpiochip_get_data(gc);
  99
 100         switch (pinconf_to_config_param(config)) {
 101         case PIN_CONFIG_DRIVE_OPEN_DRAIN:
 102                 return regmap_update_bits(gpio->lp873->regmap,
 103                                           LP873X_REG_GPO_CTRL,
 104                                           BIT(offset * BITS_PER_GPO +
 105                                           LP873X_GPO_CTRL_OD),
 106                                           BIT(offset * BITS_PER_GPO +
 107                                           LP873X_GPO_CTRL_OD));
 108
 109         case PIN_CONFIG_DRIVE_PUSH_PULL:
 110                 return regmap_update_bits(gpio->lp873->regmap,
 111                                           LP873X_REG_GPO_CTRL,
 112                                           BIT(offset * BITS_PER_GPO +
 113                                           LP873X_GPO_CTRL_OD), 0);
 114         default:
 115                 return -ENOTSUPP;
 116         }
 117 }
 118
 119 static const struct gpio_chip template_chip = {
 120         .label                  = "lp873x-gpio",
 121         .owner                  = THIS_MODULE,
 122         .request                = lp873x_gpio_request,
 123         .get_direction          = lp873x_gpio_get_direction,
 124         .direction_input        = lp873x_gpio_direction_input,
 125         .direction_output       = lp873x_gpio_direction_output,
 126         .get                    = lp873x_gpio_get,
 127         .set                    = lp873x_gpio_set,
 128         .set_config             = lp873x_gpio_set_config,
 129         .base                   = -1,
 130         .ngpio                  = 2,
 131         .can_sleep              = true,
 132 };
 133
 134 static int lp873x_gpio_probe(struct platform_device *pdev)
 135 {
 136         struct lp873x_gpio *gpio;
 137         int ret;
 138
 139         gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
 140         if (!gpio)
 141                 return -ENOMEM;
 142
 143         platform_set_drvdata(pdev, gpio);
 144
 145         gpio->lp873 = dev_get_drvdata(pdev->dev.parent);
 146         gpio->chip = template_chip;
 147         gpio->chip.parent = gpio->lp873->dev;
 148
 149         ret = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
 150         if (ret < 0) {
 151                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 152                 return ret;
 153         }
 154
 155         return 0;
 156 }
 157
 158 static const struct platform_device_id lp873x_gpio_id_table[] = {
 159         { "lp873x-gpio", },
 160         { /* sentinel */ }
 161 };
 162 MODULE_DEVICE_TABLE(platform, lp873x_gpio_id_table);
 163
 164 static struct platform_driver lp873x_gpio_driver = {
 165         .driver = {
 166                 .name = "lp873x-gpio",
 167         },
 168         .probe = lp873x_gpio_probe,
 169         .id_table = lp873x_gpio_id_table,
 170 };
 171 module_platform_driver(lp873x_gpio_driver);
 172
 173 MODULE_AUTHOR("Keerthy <j-keerthy@ti.com>");
 174 MODULE_DESCRIPTION("LP873X GPIO driver");
 175 MODULE_LICENSE("GPL v2");