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(gc: 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(map: madera->regmap, MADERA_GPIO1_CTRL_2 + reg_offset,
33 val: &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(gc: chip);
46 struct madera *madera = madera_gpio->madera;
47 unsigned int reg_offset = 2 * offset;
48
49 return regmap_update_bits(map: 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(gc: 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(map: madera->regmap, MADERA_GPIO1_CTRL_1 + reg_offset,
63 val: &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(gc: 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(map: madera->regmap,
80 MADERA_GPIO1_CTRL_2 + reg_offset,
81 MADERA_GP1_DIR_MASK, val: 0);
82 if (ret < 0)
83 return ret;
84
85 return regmap_update_bits(map: madera->regmap,
86 MADERA_GPIO1_CTRL_1 + reg_offset,
87 MADERA_GP1_LVL_MASK, val: 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(gc: 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(map: madera->regmap,
100 MADERA_GPIO1_CTRL_1 + reg_offset,
101 MADERA_GP1_LVL_MASK, val: 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(dev: 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(dev: &pdev->dev, size: 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(gc: &madera_gpio->gpio_chip, pinctl_name: "madera-pinctrl",
190 gpio_offset: 0, pin_offset: 0, npins: 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

source code of linux/drivers/gpio/gpio-madera.c