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
21struct madera_gpio {
22 struct madera *madera;
23 /* storage space for the gpio_chip we're using */
24 struct gpio_chip gpio_chip;
25};
26
27static 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
44static 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
55static 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
71static 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
91static 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
110static const 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
124static 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
192static struct platform_driver madera_gpio_driver = {
193 .driver = {
194 .name = "madera-gpio",
195 },
196 .probe = madera_gpio_probe,
197};
198
199module_platform_driver(madera_gpio_driver);
200
201MODULE_SOFTDEP("pre: pinctrl-madera");
202MODULE_DESCRIPTION("GPIO interface for Madera codecs");
203MODULE_AUTHOR("Nariman Poushin <nariman@opensource.cirrus.com>");
204MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
205MODULE_LICENSE("GPL v2");
206MODULE_ALIAS("platform:madera-gpio");
207