1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * SYSCON GPIO driver
4 *
5 * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
6 */
7
8 #include <linux/err.h>
9 #include <linux/gpio/driver.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/of_device.h>
13 #include <linux/platform_device.h>
14 #include <linux/regmap.h>
15 #include <linux/mfd/syscon.h>
16
17 #define GPIO_SYSCON_FEAT_IN BIT(0)
18 #define GPIO_SYSCON_FEAT_OUT BIT(1)
19 #define GPIO_SYSCON_FEAT_DIR BIT(2)
20
21 /* SYSCON driver is designed to use 32-bit wide registers */
22 #define SYSCON_REG_SIZE (4)
23 #define SYSCON_REG_BITS (SYSCON_REG_SIZE * 8)
24
25 /**
26 * struct syscon_gpio_data - Configuration for the device.
27 * @compatible: SYSCON driver compatible string.
28 * @flags: Set of GPIO_SYSCON_FEAT_ flags:
29 * GPIO_SYSCON_FEAT_IN: GPIOs supports input,
30 * GPIO_SYSCON_FEAT_OUT: GPIOs supports output,
31 * GPIO_SYSCON_FEAT_DIR: GPIOs supports switch direction.
32 * @bit_count: Number of bits used as GPIOs.
33 * @dat_bit_offset: Offset (in bits) to the first GPIO bit.
34 * @dir_bit_offset: Optional offset (in bits) to the first bit to switch
35 * GPIO direction (Used with GPIO_SYSCON_FEAT_DIR flag).
36 * @set: HW specific callback to assigns output value
37 * for signal "offset"
38 */
39
40 struct syscon_gpio_data {
41 unsigned int flags;
42 unsigned int bit_count;
43 unsigned int dat_bit_offset;
44 unsigned int dir_bit_offset;
45 void (*set)(struct gpio_chip *chip,
46 unsigned offset, int value);
47 };
48
49 struct syscon_gpio_priv {
50 struct gpio_chip chip;
51 struct regmap *syscon;
52 const struct syscon_gpio_data *data;
53 u32 dreg_offset;
54 u32 dir_reg_offset;
55 };
56
syscon_gpio_get(struct gpio_chip * chip,unsigned offset)57 static int syscon_gpio_get(struct gpio_chip *chip, unsigned offset)
58 {
59 struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
60 unsigned int val, offs;
61 int ret;
62
63 offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
64
65 ret = regmap_read(priv->syscon,
66 (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE, &val);
67 if (ret)
68 return ret;
69
70 return !!(val & BIT(offs % SYSCON_REG_BITS));
71 }
72
syscon_gpio_set(struct gpio_chip * chip,unsigned offset,int val)73 static void syscon_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
74 {
75 struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
76 unsigned int offs;
77
78 offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
79
80 regmap_update_bits(priv->syscon,
81 (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
82 BIT(offs % SYSCON_REG_BITS),
83 val ? BIT(offs % SYSCON_REG_BITS) : 0);
84 }
85
syscon_gpio_dir_in(struct gpio_chip * chip,unsigned offset)86 static int syscon_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
87 {
88 struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
89
90 if (priv->data->flags & GPIO_SYSCON_FEAT_DIR) {
91 unsigned int offs;
92
93 offs = priv->dir_reg_offset +
94 priv->data->dir_bit_offset + offset;
95
96 regmap_update_bits(priv->syscon,
97 (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
98 BIT(offs % SYSCON_REG_BITS), 0);
99 }
100
101 return 0;
102 }
103
syscon_gpio_dir_out(struct gpio_chip * chip,unsigned offset,int val)104 static int syscon_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int val)
105 {
106 struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
107
108 if (priv->data->flags & GPIO_SYSCON_FEAT_DIR) {
109 unsigned int offs;
110
111 offs = priv->dir_reg_offset +
112 priv->data->dir_bit_offset + offset;
113
114 regmap_update_bits(priv->syscon,
115 (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
116 BIT(offs % SYSCON_REG_BITS),
117 BIT(offs % SYSCON_REG_BITS));
118 }
119
120 chip->set(chip, offset, val);
121
122 return 0;
123 }
124
125 static const struct syscon_gpio_data clps711x_mctrl_gpio = {
126 /* ARM CLPS711X SYSFLG1 Bits 8-10 */
127 .flags = GPIO_SYSCON_FEAT_IN,
128 .bit_count = 3,
129 .dat_bit_offset = 0x40 * 8 + 8,
130 };
131
rockchip_gpio_set(struct gpio_chip * chip,unsigned int offset,int val)132 static void rockchip_gpio_set(struct gpio_chip *chip, unsigned int offset,
133 int val)
134 {
135 struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
136 unsigned int offs;
137 u8 bit;
138 u32 data;
139 int ret;
140
141 offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
142 bit = offs % SYSCON_REG_BITS;
143 data = (val ? BIT(bit) : 0) | BIT(bit + 16);
144 ret = regmap_write(priv->syscon,
145 (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
146 data);
147 if (ret < 0)
148 dev_err(chip->parent, "gpio write failed ret(%d)\n", ret);
149 }
150
151 static const struct syscon_gpio_data rockchip_rk3328_gpio_mute = {
152 /* RK3328 GPIO_MUTE is an output only pin at GRF_SOC_CON10[1] */
153 .flags = GPIO_SYSCON_FEAT_OUT,
154 .bit_count = 1,
155 .dat_bit_offset = 0x0428 * 8 + 1,
156 .set = rockchip_gpio_set,
157 };
158
159 #define KEYSTONE_LOCK_BIT BIT(0)
160
keystone_gpio_set(struct gpio_chip * chip,unsigned offset,int val)161 static void keystone_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
162 {
163 struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
164 unsigned int offs;
165 int ret;
166
167 offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
168
169 if (!val)
170 return;
171
172 ret = regmap_update_bits(
173 priv->syscon,
174 (offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
175 BIT(offs % SYSCON_REG_BITS) | KEYSTONE_LOCK_BIT,
176 BIT(offs % SYSCON_REG_BITS) | KEYSTONE_LOCK_BIT);
177 if (ret < 0)
178 dev_err(chip->parent, "gpio write failed ret(%d)\n", ret);
179 }
180
181 static const struct syscon_gpio_data keystone_dsp_gpio = {
182 /* ARM Keystone 2 */
183 .flags = GPIO_SYSCON_FEAT_OUT,
184 .bit_count = 28,
185 .dat_bit_offset = 4,
186 .set = keystone_gpio_set,
187 };
188
189 static const struct of_device_id syscon_gpio_ids[] = {
190 {
191 .compatible = "cirrus,ep7209-mctrl-gpio",
192 .data = &clps711x_mctrl_gpio,
193 },
194 {
195 .compatible = "ti,keystone-dsp-gpio",
196 .data = &keystone_dsp_gpio,
197 },
198 {
199 .compatible = "rockchip,rk3328-grf-gpio",
200 .data = &rockchip_rk3328_gpio_mute,
201 },
202 { }
203 };
204 MODULE_DEVICE_TABLE(of, syscon_gpio_ids);
205
syscon_gpio_probe(struct platform_device * pdev)206 static int syscon_gpio_probe(struct platform_device *pdev)
207 {
208 struct device *dev = &pdev->dev;
209 struct syscon_gpio_priv *priv;
210 struct device_node *np = dev->of_node;
211 int ret;
212
213 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
214 if (!priv)
215 return -ENOMEM;
216
217 priv->data = of_device_get_match_data(dev);
218
219 priv->syscon = syscon_regmap_lookup_by_phandle(np, "gpio,syscon-dev");
220 if (IS_ERR(priv->syscon) && np->parent)
221 priv->syscon = syscon_node_to_regmap(np->parent);
222 if (IS_ERR(priv->syscon))
223 return PTR_ERR(priv->syscon);
224
225 ret = of_property_read_u32_index(np, "gpio,syscon-dev", 1,
226 &priv->dreg_offset);
227 if (ret)
228 dev_err(dev, "can't read the data register offset!\n");
229
230 priv->dreg_offset <<= 3;
231
232 ret = of_property_read_u32_index(np, "gpio,syscon-dev", 2,
233 &priv->dir_reg_offset);
234 if (ret)
235 dev_dbg(dev, "can't read the dir register offset!\n");
236
237 priv->dir_reg_offset <<= 3;
238
239 priv->chip.parent = dev;
240 priv->chip.owner = THIS_MODULE;
241 priv->chip.label = dev_name(dev);
242 priv->chip.base = -1;
243 priv->chip.ngpio = priv->data->bit_count;
244 priv->chip.get = syscon_gpio_get;
245 if (priv->data->flags & GPIO_SYSCON_FEAT_IN)
246 priv->chip.direction_input = syscon_gpio_dir_in;
247 if (priv->data->flags & GPIO_SYSCON_FEAT_OUT) {
248 priv->chip.set = priv->data->set ? : syscon_gpio_set;
249 priv->chip.direction_output = syscon_gpio_dir_out;
250 }
251
252 platform_set_drvdata(pdev, priv);
253
254 return devm_gpiochip_add_data(&pdev->dev, &priv->chip, priv);
255 }
256
257 static struct platform_driver syscon_gpio_driver = {
258 .driver = {
259 .name = "gpio-syscon",
260 .of_match_table = syscon_gpio_ids,
261 },
262 .probe = syscon_gpio_probe,
263 };
264 module_platform_driver(syscon_gpio_driver);
265
266 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
267 MODULE_DESCRIPTION("SYSCON GPIO driver");
268 MODULE_LICENSE("GPL");
269
