gpio-madera.c 5.54 KB
Newer Older
1
// SPDX-License-Identifier: GPL-2.0-only
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105
/*
 * GPIO support for Cirrus Logic Madera codecs
 *
 * Copyright (C) 2015-2018 Cirrus Logic
 */

#include <linux/gpio/driver.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>

#include <linux/mfd/madera/core.h>
#include <linux/mfd/madera/pdata.h>
#include <linux/mfd/madera/registers.h>

struct madera_gpio {
	struct madera *madera;
	/* storage space for the gpio_chip we're using */
	struct gpio_chip gpio_chip;
};

static int madera_gpio_get_direction(struct gpio_chip *chip,
				     unsigned int offset)
{
	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
	struct madera *madera = madera_gpio->madera;
	unsigned int reg_offset = 2 * offset;
	unsigned int val;
	int ret;

	ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_2 + reg_offset,
			  &val);
	if (ret < 0)
		return ret;

	return !!(val & MADERA_GP1_DIR_MASK);
}

static int madera_gpio_direction_in(struct gpio_chip *chip, unsigned int offset)
{
	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
	struct madera *madera = madera_gpio->madera;
	unsigned int reg_offset = 2 * offset;

	return regmap_update_bits(madera->regmap,
				  MADERA_GPIO1_CTRL_2 + reg_offset,
				  MADERA_GP1_DIR_MASK, MADERA_GP1_DIR);
}

static int madera_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
	struct madera *madera = madera_gpio->madera;
	unsigned int reg_offset = 2 * offset;
	unsigned int val;
	int ret;

	ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_1 + reg_offset,
			  &val);
	if (ret < 0)
		return ret;

	return !!(val & MADERA_GP1_LVL_MASK);
}

static int madera_gpio_direction_out(struct gpio_chip *chip,
				     unsigned int offset, int value)
{
	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
	struct madera *madera = madera_gpio->madera;
	unsigned int reg_offset = 2 * offset;
	unsigned int reg_val = value ? MADERA_GP1_LVL : 0;
	int ret;

	ret = regmap_update_bits(madera->regmap,
				 MADERA_GPIO1_CTRL_2 + reg_offset,
				 MADERA_GP1_DIR_MASK, 0);
	if (ret < 0)
		return ret;

	return regmap_update_bits(madera->regmap,
				  MADERA_GPIO1_CTRL_1 + reg_offset,
				  MADERA_GP1_LVL_MASK, reg_val);
}

static void madera_gpio_set(struct gpio_chip *chip, unsigned int offset,
			    int value)
{
	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
	struct madera *madera = madera_gpio->madera;
	unsigned int reg_offset = 2 * offset;
	unsigned int reg_val = value ? MADERA_GP1_LVL : 0;
	int ret;

	ret = regmap_update_bits(madera->regmap,
				 MADERA_GPIO1_CTRL_1 + reg_offset,
				 MADERA_GP1_LVL_MASK, reg_val);

	/* set() doesn't return an error so log a warning */
	if (ret)
		dev_warn(madera->dev, "Failed to write to 0x%x (%d)\n",
			 MADERA_GPIO1_CTRL_1 + reg_offset, ret);
}

106
static const struct gpio_chip madera_gpio_chip = {
107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202
	.label			= "madera",
	.owner			= THIS_MODULE,
	.request		= gpiochip_generic_request,
	.free			= gpiochip_generic_free,
	.get_direction		= madera_gpio_get_direction,
	.direction_input	= madera_gpio_direction_in,
	.get			= madera_gpio_get,
	.direction_output	= madera_gpio_direction_out,
	.set			= madera_gpio_set,
	.set_config		= gpiochip_generic_config,
	.can_sleep		= true,
};

static int madera_gpio_probe(struct platform_device *pdev)
{
	struct madera *madera = dev_get_drvdata(pdev->dev.parent);
	struct madera_pdata *pdata = dev_get_platdata(madera->dev);
	struct madera_gpio *madera_gpio;
	int ret;

	madera_gpio = devm_kzalloc(&pdev->dev, sizeof(*madera_gpio),
				   GFP_KERNEL);
	if (!madera_gpio)
		return -ENOMEM;

	madera_gpio->madera = madera;

	/* Construct suitable gpio_chip from the template in madera_gpio_chip */
	madera_gpio->gpio_chip = madera_gpio_chip;
	madera_gpio->gpio_chip.parent = pdev->dev.parent;

	switch (madera->type) {
	case CS47L35:
		madera_gpio->gpio_chip.ngpio = CS47L35_NUM_GPIOS;
		break;
	case CS47L85:
	case WM1840:
		madera_gpio->gpio_chip.ngpio = CS47L85_NUM_GPIOS;
		break;
	case CS47L90:
	case CS47L91:
		madera_gpio->gpio_chip.ngpio = CS47L90_NUM_GPIOS;
		break;
	default:
		dev_err(&pdev->dev, "Unknown chip variant %d\n", madera->type);
		return -EINVAL;
	}

	/* We want to be usable on systems that don't use devicetree or acpi */
	if (pdata && pdata->gpio_base)
		madera_gpio->gpio_chip.base = pdata->gpio_base;
	else
		madera_gpio->gpio_chip.base = -1;

	ret = devm_gpiochip_add_data(&pdev->dev,
				     &madera_gpio->gpio_chip,
				     madera_gpio);
	if (ret < 0) {
		dev_dbg(&pdev->dev, "Could not register gpiochip, %d\n", ret);
		return ret;
	}

	/*
	 * This is part of a composite MFD device which can only be used with
	 * the corresponding pinctrl driver. On all supported silicon the GPIO
	 * to pinctrl mapping is fixed in the silicon, so we register it
	 * explicitly instead of requiring a redundant gpio-ranges in the
	 * devicetree.
	 * In any case we also want to work on systems that don't use devicetree
	 * or acpi.
	 */
	ret = gpiochip_add_pin_range(&madera_gpio->gpio_chip, "madera-pinctrl",
				     0, 0, madera_gpio->gpio_chip.ngpio);
	if (ret) {
		dev_dbg(&pdev->dev, "Failed to add pin range (%d)\n", ret);
		return ret;
	}

	return 0;
}

static struct platform_driver madera_gpio_driver = {
	.driver = {
		.name	= "madera-gpio",
	},
	.probe		= madera_gpio_probe,
};

module_platform_driver(madera_gpio_driver);

MODULE_SOFTDEP("pre: pinctrl-madera");
MODULE_DESCRIPTION("GPIO interface for Madera codecs");
MODULE_AUTHOR("Nariman Poushin <nariman@opensource.cirrus.com>");
MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:madera-gpio");