xref: /openbmc/linux/drivers/gpio/gpio-madera.c (revision 86db9f28)
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 
17 struct madera_gpio {
18 	struct madera *madera;
19 	/* storage space for the gpio_chip we're using */
20 	struct gpio_chip gpio_chip;
21 };
22 
23 static 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 	return !!(val & MADERA_GP1_DIR_MASK);
38 }
39 
40 static int madera_gpio_direction_in(struct gpio_chip *chip, unsigned int offset)
41 {
42 	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
43 	struct madera *madera = madera_gpio->madera;
44 	unsigned int reg_offset = 2 * offset;
45 
46 	return regmap_update_bits(madera->regmap,
47 				  MADERA_GPIO1_CTRL_2 + reg_offset,
48 				  MADERA_GP1_DIR_MASK, MADERA_GP1_DIR);
49 }
50 
51 static int madera_gpio_get(struct gpio_chip *chip, unsigned int offset)
52 {
53 	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
54 	struct madera *madera = madera_gpio->madera;
55 	unsigned int reg_offset = 2 * offset;
56 	unsigned int val;
57 	int ret;
58 
59 	ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_1 + reg_offset,
60 			  &val);
61 	if (ret < 0)
62 		return ret;
63 
64 	return !!(val & MADERA_GP1_LVL_MASK);
65 }
66 
67 static int madera_gpio_direction_out(struct gpio_chip *chip,
68 				     unsigned int offset, int value)
69 {
70 	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
71 	struct madera *madera = madera_gpio->madera;
72 	unsigned int reg_offset = 2 * offset;
73 	unsigned int reg_val = value ? MADERA_GP1_LVL : 0;
74 	int ret;
75 
76 	ret = regmap_update_bits(madera->regmap,
77 				 MADERA_GPIO1_CTRL_2 + reg_offset,
78 				 MADERA_GP1_DIR_MASK, 0);
79 	if (ret < 0)
80 		return ret;
81 
82 	return regmap_update_bits(madera->regmap,
83 				  MADERA_GPIO1_CTRL_1 + reg_offset,
84 				  MADERA_GP1_LVL_MASK, reg_val);
85 }
86 
87 static void madera_gpio_set(struct gpio_chip *chip, unsigned int offset,
88 			    int value)
89 {
90 	struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
91 	struct madera *madera = madera_gpio->madera;
92 	unsigned int reg_offset = 2 * offset;
93 	unsigned int reg_val = value ? MADERA_GP1_LVL : 0;
94 	int ret;
95 
96 	ret = regmap_update_bits(madera->regmap,
97 				 MADERA_GPIO1_CTRL_1 + reg_offset,
98 				 MADERA_GP1_LVL_MASK, reg_val);
99 
100 	/* set() doesn't return an error so log a warning */
101 	if (ret)
102 		dev_warn(madera->dev, "Failed to write to 0x%x (%d)\n",
103 			 MADERA_GPIO1_CTRL_1 + reg_offset, ret);
104 }
105 
106 static const struct gpio_chip madera_gpio_chip = {
107 	.label			= "madera",
108 	.owner			= THIS_MODULE,
109 	.request		= gpiochip_generic_request,
110 	.free			= gpiochip_generic_free,
111 	.get_direction		= madera_gpio_get_direction,
112 	.direction_input	= madera_gpio_direction_in,
113 	.get			= madera_gpio_get,
114 	.direction_output	= madera_gpio_direction_out,
115 	.set			= madera_gpio_set,
116 	.set_config		= gpiochip_generic_config,
117 	.can_sleep		= true,
118 };
119 
120 static int madera_gpio_probe(struct platform_device *pdev)
121 {
122 	struct madera *madera = dev_get_drvdata(pdev->dev.parent);
123 	struct madera_pdata *pdata = &madera->pdata;
124 	struct madera_gpio *madera_gpio;
125 	int ret;
126 
127 	madera_gpio = devm_kzalloc(&pdev->dev, sizeof(*madera_gpio),
128 				   GFP_KERNEL);
129 	if (!madera_gpio)
130 		return -ENOMEM;
131 
132 	madera_gpio->madera = madera;
133 
134 	/* Construct suitable gpio_chip from the template in madera_gpio_chip */
135 	madera_gpio->gpio_chip = madera_gpio_chip;
136 	madera_gpio->gpio_chip.parent = pdev->dev.parent;
137 
138 	switch (madera->type) {
139 	case CS47L15:
140 		madera_gpio->gpio_chip.ngpio = CS47L15_NUM_GPIOS;
141 		break;
142 	case CS47L35:
143 		madera_gpio->gpio_chip.ngpio = CS47L35_NUM_GPIOS;
144 		break;
145 	case CS47L85:
146 	case WM1840:
147 		madera_gpio->gpio_chip.ngpio = CS47L85_NUM_GPIOS;
148 		break;
149 	case CS47L90:
150 	case CS47L91:
151 		madera_gpio->gpio_chip.ngpio = CS47L90_NUM_GPIOS;
152 		break;
153 	case CS42L92:
154 	case CS47L92:
155 	case CS47L93:
156 		madera_gpio->gpio_chip.ngpio = CS47L92_NUM_GPIOS;
157 		break;
158 	default:
159 		dev_err(&pdev->dev, "Unknown chip variant %d\n", madera->type);
160 		return -EINVAL;
161 	}
162 
163 	/* We want to be usable on systems that don't use devicetree or acpi */
164 	if (pdata->gpio_base)
165 		madera_gpio->gpio_chip.base = pdata->gpio_base;
166 	else
167 		madera_gpio->gpio_chip.base = -1;
168 
169 	ret = devm_gpiochip_add_data(&pdev->dev,
170 				     &madera_gpio->gpio_chip,
171 				     madera_gpio);
172 	if (ret < 0) {
173 		dev_dbg(&pdev->dev, "Could not register gpiochip, %d\n", ret);
174 		return ret;
175 	}
176 
177 	/*
178 	 * This is part of a composite MFD device which can only be used with
179 	 * the corresponding pinctrl driver. On all supported silicon the GPIO
180 	 * to pinctrl mapping is fixed in the silicon, so we register it
181 	 * explicitly instead of requiring a redundant gpio-ranges in the
182 	 * devicetree.
183 	 * In any case we also want to work on systems that don't use devicetree
184 	 * or acpi.
185 	 */
186 	ret = gpiochip_add_pin_range(&madera_gpio->gpio_chip, "madera-pinctrl",
187 				     0, 0, madera_gpio->gpio_chip.ngpio);
188 	if (ret) {
189 		dev_dbg(&pdev->dev, "Failed to add pin range (%d)\n", ret);
190 		return ret;
191 	}
192 
193 	return 0;
194 }
195 
196 static struct platform_driver madera_gpio_driver = {
197 	.driver = {
198 		.name	= "madera-gpio",
199 	},
200 	.probe		= madera_gpio_probe,
201 };
202 
203 module_platform_driver(madera_gpio_driver);
204 
205 MODULE_SOFTDEP("pre: pinctrl-madera");
206 MODULE_DESCRIPTION("GPIO interface for Madera codecs");
207 MODULE_AUTHOR("Nariman Poushin <nariman@opensource.cirrus.com>");
208 MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
209 MODULE_LICENSE("GPL v2");
210 MODULE_ALIAS("platform:madera-gpio");
211