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 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
109static 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
123static 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
199static struct platform_driver madera_gpio_driver = {
200	.driver = {
201		.name	= "madera-gpio",
202	},
203	.probe		= madera_gpio_probe,
204};
205
206module_platform_driver(madera_gpio_driver);
207
208MODULE_SOFTDEP("pre: pinctrl-madera");
209MODULE_DESCRIPTION("GPIO interface for Madera codecs");
210MODULE_AUTHOR("Nariman Poushin <nariman@opensource.cirrus.com>");
211MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
212MODULE_LICENSE("GPL v2");
213MODULE_ALIAS("platform:madera-gpio");
214