drivers/gpio/gpio-madera.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * GPIO support for Cirrus Logic Madera codecs
   4  *
   5  * Copyright (C) 2015-2018 Cirrus Logic
   6  */
   7
   8 #include <linux/gpio/driver.h>
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12
  13 #include <linux/mfd/madera/core.h>
  14 #include <linux/mfd/madera/pdata.h>
  15 #include <linux/mfd/madera/registers.h>
  16
  17 struct madera_gpio {
  18         struct madera *madera;
  19         /* storage space for the gpio_chip we're using */
  20         struct gpio_chip gpio_chip;
  21 };
  22
  23 static int madera_gpio_get_direction(struct gpio_chip *chip,
  24                                      unsigned int offset)
  25 {
  26         struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
  27         struct madera *madera = madera_gpio->madera;
  28         unsigned int reg_offset = 2 * offset;
  29         unsigned int val;
  30         int ret;
  31
  32         ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_2 + reg_offset,
  33                           &val);
  34         if (ret < 0)
  35                 return ret;
  36
  37         if (val & MADERA_GP1_DIR_MASK)
  38                 return GPIO_LINE_DIRECTION_IN;
  39
  40         return GPIO_LINE_DIRECTION_OUT;
  41 }
  42
  43 static int madera_gpio_direction_in(struct gpio_chip *chip, unsigned int offset)
  44 {
  45         struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
  46         struct madera *madera = madera_gpio->madera;
  47         unsigned int reg_offset = 2 * offset;
  48
  49         return regmap_update_bits(madera->regmap,
  50                                   MADERA_GPIO1_CTRL_2 + reg_offset,
  51                                   MADERA_GP1_DIR_MASK, MADERA_GP1_DIR);
  52 }
  53
  54 static int madera_gpio_get(struct gpio_chip *chip, unsigned int offset)
  55 {
  56         struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
  57         struct madera *madera = madera_gpio->madera;
  58         unsigned int reg_offset = 2 * offset;
  59         unsigned int val;
  60         int ret;
  61
  62         ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_1 + reg_offset,
  63                           &val);
  64         if (ret < 0)
  65                 return ret;
  66
  67         return !!(val & MADERA_GP1_LVL_MASK);
  68 }
  69
  70 static int madera_gpio_direction_out(struct gpio_chip *chip,
  71                                      unsigned int offset, int value)
  72 {
  73         struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
  74         struct madera *madera = madera_gpio->madera;
  75         unsigned int reg_offset = 2 * offset;
  76         unsigned int reg_val = value ? MADERA_GP1_LVL : 0;
  77         int ret;
  78
  79         ret = regmap_update_bits(madera->regmap,
  80                                  MADERA_GPIO1_CTRL_2 + reg_offset,
  81                                  MADERA_GP1_DIR_MASK, 0);
  82         if (ret < 0)
  83                 return ret;
  84
  85         return regmap_update_bits(madera->regmap,
  86                                   MADERA_GPIO1_CTRL_1 + reg_offset,
  87                                   MADERA_GP1_LVL_MASK, reg_val);
  88 }
  89
  90 static void madera_gpio_set(struct gpio_chip *chip, unsigned int offset,
  91                             int value)
  92 {
  93         struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
  94         struct madera *madera = madera_gpio->madera;
  95         unsigned int reg_offset = 2 * offset;
  96         unsigned int reg_val = value ? MADERA_GP1_LVL : 0;
  97         int ret;
  98
  99         ret = regmap_update_bits(madera->regmap,
 100                                  MADERA_GPIO1_CTRL_1 + reg_offset,
 101                                  MADERA_GP1_LVL_MASK, reg_val);
 102
 103         /* set() doesn't return an error so log a warning */
 104         if (ret)
 105                 dev_warn(madera->dev, "Failed to write to 0x%x (%d)\n",
 106                          MADERA_GPIO1_CTRL_1 + reg_offset, ret);
 107 }
 108
 109 static const struct gpio_chip madera_gpio_chip = {
 110         .label                  = "madera",
 111         .owner                  = THIS_MODULE,
 112         .request                = gpiochip_generic_request,
 113         .free                   = gpiochip_generic_free,
 114         .get_direction          = madera_gpio_get_direction,
 115         .direction_input        = madera_gpio_direction_in,
 116         .get                    = madera_gpio_get,
 117         .direction_output       = madera_gpio_direction_out,
 118         .set                    = madera_gpio_set,
 119         .set_config             = gpiochip_generic_config,
 120         .can_sleep              = true,
 121 };
 122
 123 static int madera_gpio_probe(struct platform_device *pdev)
 124 {
 125         struct madera *madera = dev_get_drvdata(pdev->dev.parent);
 126         struct madera_pdata *pdata = &madera->pdata;
 127         struct madera_gpio *madera_gpio;
 128         int ret;
 129
 130         madera_gpio = devm_kzalloc(&pdev->dev, sizeof(*madera_gpio),
 131                                    GFP_KERNEL);
 132         if (!madera_gpio)
 133                 return -ENOMEM;
 134
 135         madera_gpio->madera = madera;
 136
 137         /* Construct suitable gpio_chip from the template in madera_gpio_chip */
 138         madera_gpio->gpio_chip = madera_gpio_chip;
 139         madera_gpio->gpio_chip.parent = pdev->dev.parent;
 140
 141         switch (madera->type) {
 142         case CS47L15:
 143                 madera_gpio->gpio_chip.ngpio = CS47L15_NUM_GPIOS;
 144                 break;
 145         case CS47L35:
 146                 madera_gpio->gpio_chip.ngpio = CS47L35_NUM_GPIOS;
 147                 break;
 148         case CS47L85:
 149         case WM1840:
 150                 madera_gpio->gpio_chip.ngpio = CS47L85_NUM_GPIOS;
 151                 break;
 152         case CS47L90:
 153         case CS47L91:
 154                 madera_gpio->gpio_chip.ngpio = CS47L90_NUM_GPIOS;
 155                 break;
 156         case CS42L92:
 157         case CS47L92:
 158         case CS47L93:
 159                 madera_gpio->gpio_chip.ngpio = CS47L92_NUM_GPIOS;
 160                 break;
 161         default:
 162                 dev_err(&pdev->dev, "Unknown chip variant %d\n", madera->type);
 163                 return -EINVAL;
 164         }
 165
 166         /* We want to be usable on systems that don't use devicetree or acpi */
 167         if (pdata->gpio_base)
 168                 madera_gpio->gpio_chip.base = pdata->gpio_base;
 169         else
 170                 madera_gpio->gpio_chip.base = -1;
 171
 172         ret = devm_gpiochip_add_data(&pdev->dev,
 173                                      &madera_gpio->gpio_chip,
 174                                      madera_gpio);
 175         if (ret < 0) {
 176                 dev_dbg(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 177                 return ret;
 178         }
 179
 180         /*
 181          * This is part of a composite MFD device which can only be used with
 182          * the corresponding pinctrl driver. On all supported silicon the GPIO
 183          * to pinctrl mapping is fixed in the silicon, so we register it
 184          * explicitly instead of requiring a redundant gpio-ranges in the
 185          * devicetree.
 186          * In any case we also want to work on systems that don't use devicetree
 187          * or acpi.
 188          */
 189         ret = gpiochip_add_pin_range(&madera_gpio->gpio_chip, "madera-pinctrl",
 190                                      0, 0, madera_gpio->gpio_chip.ngpio);
 191         if (ret) {
 192                 dev_dbg(&pdev->dev, "Failed to add pin range (%d)\n", ret);
 193                 return ret;
 194         }
 195
 196         return 0;
 197 }
 198
 199 static struct platform_driver madera_gpio_driver = {
 200         .driver = {
 201                 .name   = "madera-gpio",
 202         },
 203         .probe          = madera_gpio_probe,
 204 };
 205
 206 module_platform_driver(madera_gpio_driver);
 207
 208 MODULE_SOFTDEP("pre: pinctrl-madera");
 209 MODULE_DESCRIPTION("GPIO interface for Madera codecs");
 210 MODULE_AUTHOR("Nariman Poushin <nariman@opensource.cirrus.com>");
 211 MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
 212 MODULE_LICENSE("GPL v2");
 213 MODULE_ALIAS("platform:madera-gpio");