drivers/gpio/gpio-madera.c

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