drivers/gpio/gpio-madera.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * GPIO support for Cirrus Logic Madera codecs
0004  *
0005  * Copyright (C) 2015-2018 Cirrus Logic
0006  */
0007
0008 #include <linux/gpio/driver.h>
0009 #include <linux/kernel.h>
0010 #include <linux/module.h>
0011 #include <linux/platform_device.h>
0012
0013 #include <linux/mfd/madera/core.h>
0014 #include <linux/mfd/madera/pdata.h>
0015 #include <linux/mfd/madera/registers.h>
0016
0017 struct madera_gpio {
0018     struct madera *madera;
0019     /* storage space for the gpio_chip we're using */
0020     struct gpio_chip gpio_chip;
0021 };
0022
0023 static int madera_gpio_get_direction(struct gpio_chip *chip,
0024                      unsigned int offset)
0025 {
0026     struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
0027     struct madera *madera = madera_gpio->madera;
0028     unsigned int reg_offset = 2 * offset;
0029     unsigned int val;
0030     int ret;
0031
0032     ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_2 + reg_offset,
0033               &val);
0034     if (ret < 0)
0035         return ret;
0036
0037     if (val & MADERA_GP1_DIR_MASK)
0038         return GPIO_LINE_DIRECTION_IN;
0039
0040     return GPIO_LINE_DIRECTION_OUT;
0041 }
0042
0043 static int madera_gpio_direction_in(struct gpio_chip *chip, unsigned int offset)
0044 {
0045     struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
0046     struct madera *madera = madera_gpio->madera;
0047     unsigned int reg_offset = 2 * offset;
0048
0049     return regmap_update_bits(madera->regmap,
0050                   MADERA_GPIO1_CTRL_2 + reg_offset,
0051                   MADERA_GP1_DIR_MASK, MADERA_GP1_DIR);
0052 }
0053
0054 static int madera_gpio_get(struct gpio_chip *chip, unsigned int offset)
0055 {
0056     struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
0057     struct madera *madera = madera_gpio->madera;
0058     unsigned int reg_offset = 2 * offset;
0059     unsigned int val;
0060     int ret;
0061
0062     ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_1 + reg_offset,
0063               &val);
0064     if (ret < 0)
0065         return ret;
0066
0067     return !!(val & MADERA_GP1_LVL_MASK);
0068 }
0069
0070 static int madera_gpio_direction_out(struct gpio_chip *chip,
0071                      unsigned int offset, int value)
0072 {
0073     struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
0074     struct madera *madera = madera_gpio->madera;
0075     unsigned int reg_offset = 2 * offset;
0076     unsigned int reg_val = value ? MADERA_GP1_LVL : 0;
0077     int ret;
0078
0079     ret = regmap_update_bits(madera->regmap,
0080                  MADERA_GPIO1_CTRL_2 + reg_offset,
0081                  MADERA_GP1_DIR_MASK, 0);
0082     if (ret < 0)
0083         return ret;
0084
0085     return regmap_update_bits(madera->regmap,
0086                   MADERA_GPIO1_CTRL_1 + reg_offset,
0087                   MADERA_GP1_LVL_MASK, reg_val);
0088 }
0089
0090 static void madera_gpio_set(struct gpio_chip *chip, unsigned int offset,
0091                 int value)
0092 {
0093     struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
0094     struct madera *madera = madera_gpio->madera;
0095     unsigned int reg_offset = 2 * offset;
0096     unsigned int reg_val = value ? MADERA_GP1_LVL : 0;
0097     int ret;
0098
0099     ret = regmap_update_bits(madera->regmap,
0100                  MADERA_GPIO1_CTRL_1 + reg_offset,
0101                  MADERA_GP1_LVL_MASK, reg_val);
0102
0103     /* set() doesn't return an error so log a warning */
0104     if (ret)
0105         dev_warn(madera->dev, "Failed to write to 0x%x (%d)\n",
0106              MADERA_GPIO1_CTRL_1 + reg_offset, ret);
0107 }
0108
0109 static const struct gpio_chip madera_gpio_chip = {
0110     .label          = "madera",
0111     .owner          = THIS_MODULE,
0112     .request        = gpiochip_generic_request,
0113     .free           = gpiochip_generic_free,
0114     .get_direction      = madera_gpio_get_direction,
0115     .direction_input    = madera_gpio_direction_in,
0116     .get            = madera_gpio_get,
0117     .direction_output   = madera_gpio_direction_out,
0118     .set            = madera_gpio_set,
0119     .set_config     = gpiochip_generic_config,
0120     .can_sleep      = true,
0121 };
0122
0123 static int madera_gpio_probe(struct platform_device *pdev)
0124 {
0125     struct madera *madera = dev_get_drvdata(pdev->dev.parent);
0126     struct madera_pdata *pdata = &madera->pdata;
0127     struct madera_gpio *madera_gpio;
0128     int ret;
0129
0130     madera_gpio = devm_kzalloc(&pdev->dev, sizeof(*madera_gpio),
0131                    GFP_KERNEL);
0132     if (!madera_gpio)
0133         return -ENOMEM;
0134
0135     madera_gpio->madera = madera;
0136
0137     /* Construct suitable gpio_chip from the template in madera_gpio_chip */
0138     madera_gpio->gpio_chip = madera_gpio_chip;
0139     madera_gpio->gpio_chip.parent = pdev->dev.parent;
0140
0141     switch (madera->type) {
0142     case CS47L15:
0143         madera_gpio->gpio_chip.ngpio = CS47L15_NUM_GPIOS;
0144         break;
0145     case CS47L35:
0146         madera_gpio->gpio_chip.ngpio = CS47L35_NUM_GPIOS;
0147         break;
0148     case CS47L85:
0149     case WM1840:
0150         madera_gpio->gpio_chip.ngpio = CS47L85_NUM_GPIOS;
0151         break;
0152     case CS47L90:
0153     case CS47L91:
0154         madera_gpio->gpio_chip.ngpio = CS47L90_NUM_GPIOS;
0155         break;
0156     case CS42L92:
0157     case CS47L92:
0158     case CS47L93:
0159         madera_gpio->gpio_chip.ngpio = CS47L92_NUM_GPIOS;
0160         break;
0161     default:
0162         dev_err(&pdev->dev, "Unknown chip variant %d\n", madera->type);
0163         return -EINVAL;
0164     }
0165
0166     /* We want to be usable on systems that don't use devicetree or acpi */
0167     if (pdata->gpio_base)
0168         madera_gpio->gpio_chip.base = pdata->gpio_base;
0169     else
0170         madera_gpio->gpio_chip.base = -1;
0171
0172     ret = devm_gpiochip_add_data(&pdev->dev,
0173                      &madera_gpio->gpio_chip,
0174                      madera_gpio);
0175     if (ret < 0) {
0176         dev_dbg(&pdev->dev, "Could not register gpiochip, %d\n", ret);
0177         return ret;
0178     }
0179
0180     /*
0181      * This is part of a composite MFD device which can only be used with
0182      * the corresponding pinctrl driver. On all supported silicon the GPIO
0183      * to pinctrl mapping is fixed in the silicon, so we register it
0184      * explicitly instead of requiring a redundant gpio-ranges in the
0185      * devicetree.
0186      * In any case we also want to work on systems that don't use devicetree
0187      * or acpi.
0188      */
0189     ret = gpiochip_add_pin_range(&madera_gpio->gpio_chip, "madera-pinctrl",
0190                      0, 0, madera_gpio->gpio_chip.ngpio);
0191     if (ret) {
0192         dev_dbg(&pdev->dev, "Failed to add pin range (%d)\n", ret);
0193         return ret;
0194     }
0195
0196     return 0;
0197 }
0198
0199 static struct platform_driver madera_gpio_driver = {
0200     .driver = {
0201         .name   = "madera-gpio",
0202     },
0203     .probe      = madera_gpio_probe,
0204 };
0205
0206 module_platform_driver(madera_gpio_driver);
0207
0208 MODULE_SOFTDEP("pre: pinctrl-madera");
0209 MODULE_DESCRIPTION("GPIO interface for Madera codecs");
0210 MODULE_AUTHOR("Nariman Poushin <nariman@opensource.cirrus.com>");
0211 MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
0212 MODULE_LICENSE("GPL v2");
0213 MODULE_ALIAS("platform:madera-gpio");