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
 17struct madera_gpio {
 18	struct madera *madera;
 19	/* storage space for the gpio_chip we're using */
 20	struct gpio_chip gpio_chip;
 21};
 22
 23static 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
 43static 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
 54static 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
 70static 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
 90static int 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
 98	return regmap_update_bits(madera->regmap,
 99				  MADERA_GPIO1_CTRL_1 + reg_offset,
100				  MADERA_GP1_LVL_MASK, reg_val);
101}
102
103static const struct gpio_chip madera_gpio_chip = {
104	.label			= "madera",
105	.owner			= THIS_MODULE,
106	.request		= gpiochip_generic_request,
107	.free			= gpiochip_generic_free,
108	.get_direction		= madera_gpio_get_direction,
109	.direction_input	= madera_gpio_direction_in,
110	.get			= madera_gpio_get,
111	.direction_output	= madera_gpio_direction_out,
112	.set			= madera_gpio_set,
113	.set_config		= gpiochip_generic_config,
114	.can_sleep		= true,
115};
116
117static int madera_gpio_probe(struct platform_device *pdev)
118{
119	struct madera *madera = dev_get_drvdata(pdev->dev.parent);
120	struct madera_pdata *pdata = &madera->pdata;
121	struct madera_gpio *madera_gpio;
122	int ret;
123
124	madera_gpio = devm_kzalloc(&pdev->dev, sizeof(*madera_gpio),
125				   GFP_KERNEL);
126	if (!madera_gpio)
127		return -ENOMEM;
128
129	madera_gpio->madera = madera;
130
131	/* Construct suitable gpio_chip from the template in madera_gpio_chip */
132	madera_gpio->gpio_chip = madera_gpio_chip;
133	madera_gpio->gpio_chip.parent = pdev->dev.parent;
134
135	switch (madera->type) {
136	case CS47L15:
137		madera_gpio->gpio_chip.ngpio = CS47L15_NUM_GPIOS;
138		break;
139	case CS47L35:
140		madera_gpio->gpio_chip.ngpio = CS47L35_NUM_GPIOS;
141		break;
142	case CS47L85:
143	case WM1840:
144		madera_gpio->gpio_chip.ngpio = CS47L85_NUM_GPIOS;
145		break;
146	case CS47L90:
147	case CS47L91:
148		madera_gpio->gpio_chip.ngpio = CS47L90_NUM_GPIOS;
149		break;
150	case CS42L92:
151	case CS47L92:
152	case CS47L93:
153		madera_gpio->gpio_chip.ngpio = CS47L92_NUM_GPIOS;
154		break;
155	default:
156		dev_err(&pdev->dev, "Unknown chip variant %d\n", madera->type);
157		return -EINVAL;
158	}
159
160	/* We want to be usable on systems that don't use devicetree or acpi */
161	if (pdata->gpio_base)
162		madera_gpio->gpio_chip.base = pdata->gpio_base;
163	else
164		madera_gpio->gpio_chip.base = -1;
165
166	ret = devm_gpiochip_add_data(&pdev->dev,
167				     &madera_gpio->gpio_chip,
168				     madera_gpio);
169	if (ret < 0) {
170		dev_dbg(&pdev->dev, "Could not register gpiochip, %d\n", ret);
171		return ret;
172	}
173
174	/*
175	 * This is part of a composite MFD device which can only be used with
176	 * the corresponding pinctrl driver. On all supported silicon the GPIO
177	 * to pinctrl mapping is fixed in the silicon, so we register it
178	 * explicitly instead of requiring a redundant gpio-ranges in the
179	 * devicetree.
180	 * In any case we also want to work on systems that don't use devicetree
181	 * or acpi.
182	 */
183	ret = gpiochip_add_pin_range(&madera_gpio->gpio_chip, "madera-pinctrl",
184				     0, 0, madera_gpio->gpio_chip.ngpio);
185	if (ret) {
186		dev_dbg(&pdev->dev, "Failed to add pin range (%d)\n", ret);
187		return ret;
188	}
189
190	return 0;
191}
192
193static struct platform_driver madera_gpio_driver = {
194	.driver = {
195		.name	= "madera-gpio",
196	},
197	.probe		= madera_gpio_probe,
198};
199
200module_platform_driver(madera_gpio_driver);
201
202MODULE_SOFTDEP("pre: pinctrl-madera");
203MODULE_DESCRIPTION("GPIO interface for Madera codecs");
204MODULE_AUTHOR("Nariman Poushin <nariman@opensource.cirrus.com>");
205MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
206MODULE_LICENSE("GPL v2");
207MODULE_ALIAS("platform:madera-gpio");