drivers/gpio/gpio-bd71828.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 // Copyright (C) 2018 ROHM Semiconductors
   3
   4 #include <linux/gpio/driver.h>
   5 #include <linux/mfd/rohm-bd71828.h>
   6 #include <linux/module.h>
   7 #include <linux/platform_device.h>
   8 #include <linux/regmap.h>
   9
  10 #define GPIO_OUT_REG(off) (BD71828_REG_GPIO_CTRL1 + (off))
  11 #define HALL_GPIO_OFFSET 3
  12
  13 struct bd71828_gpio {
  14         struct rohm_regmap_dev chip;
  15         struct gpio_chip gpio;
  16 };
  17
  18 static void bd71828_gpio_set(struct gpio_chip *chip, unsigned int offset,
  19                              int value)
  20 {
  21         int ret;
  22         struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
  23         u8 val = (value) ? BD71828_GPIO_OUT_HI : BD71828_GPIO_OUT_LO;
  24
  25         /*
  26          * The HALL input pin can only be used as input. If this is the pin
  27          * we are dealing with - then we are done
  28          */
  29         if (offset == HALL_GPIO_OFFSET)
  30                 return;
  31
  32         ret = regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
  33                                  BD71828_GPIO_OUT_MASK, val);
  34         if (ret)
  35                 dev_err(bdgpio->chip.dev, "Could not set gpio to %d\n", value);
  36 }
  37
  38 static int bd71828_gpio_get(struct gpio_chip *chip, unsigned int offset)
  39 {
  40         int ret;
  41         unsigned int val;
  42         struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
  43
  44         if (offset == HALL_GPIO_OFFSET)
  45                 ret = regmap_read(bdgpio->chip.regmap, BD71828_REG_IO_STAT,
  46                                   &val);
  47         else
  48                 ret = regmap_read(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
  49                                   &val);
  50         if (!ret)
  51                 ret = (val & BD71828_GPIO_OUT_MASK);
  52
  53         return ret;
  54 }
  55
  56 static int bd71828_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
  57                                    unsigned long config)
  58 {
  59         struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
  60
  61         if (offset == HALL_GPIO_OFFSET)
  62                 return -ENOTSUPP;
  63
  64         switch (pinconf_to_config_param(config)) {
  65         case PIN_CONFIG_DRIVE_OPEN_DRAIN:
  66                 return regmap_update_bits(bdgpio->chip.regmap,
  67                                           GPIO_OUT_REG(offset),
  68                                           BD71828_GPIO_DRIVE_MASK,
  69                                           BD71828_GPIO_OPEN_DRAIN);
  70         case PIN_CONFIG_DRIVE_PUSH_PULL:
  71                 return regmap_update_bits(bdgpio->chip.regmap,
  72                                           GPIO_OUT_REG(offset),
  73                                           BD71828_GPIO_DRIVE_MASK,
  74                                           BD71828_GPIO_PUSH_PULL);
  75         default:
  76                 break;
  77         }
  78         return -ENOTSUPP;
  79 }
  80
  81 static int bd71828_get_direction(struct gpio_chip *chip, unsigned int offset)
  82 {
  83         /*
  84          * Pin usage is selected by OTP data. We can't read it runtime. Hence
  85          * we trust that if the pin is not excluded by "gpio-reserved-ranges"
  86          * the OTP configuration is set to OUT. (Other pins but HALL input pin
  87          * on BD71828 can't really be used for general purpose input - input
  88          * states are used for specific cases like regulator control or
  89          * PMIC_ON_REQ.
  90          */
  91         if (offset == HALL_GPIO_OFFSET)
  92                 return GPIO_LINE_DIRECTION_IN;
  93
  94         return GPIO_LINE_DIRECTION_OUT;
  95 }
  96
  97 static int bd71828_probe(struct platform_device *pdev)
  98 {
  99         struct bd71828_gpio *bdgpio;
 100         struct rohm_regmap_dev *bd71828;
 101
 102         bd71828 = dev_get_drvdata(pdev->dev.parent);
 103         if (!bd71828) {
 104                 dev_err(&pdev->dev, "No MFD driver data\n");
 105                 return -EINVAL;
 106         }
 107
 108         bdgpio = devm_kzalloc(&pdev->dev, sizeof(*bdgpio),
 109                               GFP_KERNEL);
 110         if (!bdgpio)
 111                 return -ENOMEM;
 112
 113         bdgpio->chip.dev = &pdev->dev;
 114         bdgpio->gpio.parent = pdev->dev.parent;
 115         bdgpio->gpio.label = "bd71828-gpio";
 116         bdgpio->gpio.owner = THIS_MODULE;
 117         bdgpio->gpio.get_direction = bd71828_get_direction;
 118         bdgpio->gpio.set_config = bd71828_gpio_set_config;
 119         bdgpio->gpio.can_sleep = true;
 120         bdgpio->gpio.get = bd71828_gpio_get;
 121         bdgpio->gpio.set = bd71828_gpio_set;
 122         bdgpio->gpio.base = -1;
 123
 124         /*
 125          * See if we need some implementation to mark some PINs as
 126          * not controllable based on DT info or if core can handle
 127          * "gpio-reserved-ranges" and exclude them from control
 128          */
 129         bdgpio->gpio.ngpio = 4;
 130         bdgpio->gpio.of_node = pdev->dev.parent->of_node;
 131         bdgpio->chip.regmap = bd71828->regmap;
 132
 133         return devm_gpiochip_add_data(&pdev->dev, &bdgpio->gpio,
 134                                      bdgpio);
 135 }
 136
 137 static struct platform_driver bd71828_gpio = {
 138         .driver = {
 139                 .name = "bd71828-gpio"
 140         },
 141         .probe = bd71828_probe,
 142 };
 143
 144 module_platform_driver(bd71828_gpio);
 145
 146 MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
 147 MODULE_DESCRIPTION("BD71828 voltage regulator driver");
 148 MODULE_LICENSE("GPL");
 149 MODULE_ALIAS("platform:bd71828-gpio");