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 
madera_gpio_get_direction(struct gpio_chip * chip,unsigned int offset)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 	if (val & MADERA_GP1_DIR_MASK)
38 		return GPIO_LINE_DIRECTION_IN;
39 
40 	return GPIO_LINE_DIRECTION_OUT;
41 }
42 
madera_gpio_direction_in(struct gpio_chip * chip,unsigned int offset)43 static 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 
madera_gpio_get(struct gpio_chip * chip,unsigned int offset)54 static 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 
madera_gpio_direction_out(struct gpio_chip * chip,unsigned int offset,int value)70 static 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 
madera_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)90 static 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 
109 static 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 
madera_gpio_probe(struct platform_device * pdev)123 static 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 
199 static struct platform_driver madera_gpio_driver = {
200 	.driver = {
201 		.name	= "madera-gpio",
202 	},
203 	.probe		= madera_gpio_probe,
204 };
205 
206 module_platform_driver(madera_gpio_driver);
207 
208 MODULE_SOFTDEP("pre: pinctrl-madera");
209 MODULE_DESCRIPTION("GPIO interface for Madera codecs");
210 MODULE_AUTHOR("Nariman Poushin <nariman@opensource.cirrus.com>");
211 MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
212 MODULE_LICENSE("GPL v2");
213 MODULE_ALIAS("platform:madera-gpio");
214