1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2021, Collabora Ltd.
4 * Copyright (C) 2021, General Electric Company
5 * Author(s): Sebastian Reichel <sebastian.reichel@collabora.com>
6 */
7
8 #define LOG_CATEGORY UCLASS_GPIO
9
10 #include <common.h>
11 #include <errno.h>
12 #include <dm.h>
13 #include <i2c.h>
14 #include <asm/gpio.h>
15 #include <dm/device_compat.h>
16 #include <dt-bindings/gpio/gpio.h>
17
18 enum mcp230xx_type {
19 UNKNOWN = 0,
20 MCP23008,
21 MCP23017,
22 MCP23018,
23 };
24
25 #define MCP230XX_IODIR 0x00
26 #define MCP230XX_GPPU 0x06
27 #define MCP230XX_GPIO 0x09
28 #define MCP230XX_OLAT 0x0a
29
30 #define BANKSIZE 8
31
mcp230xx_read(struct udevice * dev,uint reg,uint offset)32 static int mcp230xx_read(struct udevice *dev, uint reg, uint offset)
33 {
34 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
35 int bank = offset / BANKSIZE;
36 int mask = 1 << (offset % BANKSIZE);
37 int shift = (uc_priv->gpio_count / BANKSIZE) - 1;
38 int ret;
39
40 ret = dm_i2c_reg_read(dev, (reg << shift) | bank);
41 if (ret < 0)
42 return ret;
43
44 return !!(ret & mask);
45 }
46
mcp230xx_write(struct udevice * dev,uint reg,uint offset,bool val)47 static int mcp230xx_write(struct udevice *dev, uint reg, uint offset, bool val)
48 {
49 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
50 int bank = offset / BANKSIZE;
51 int mask = 1 << (offset % BANKSIZE);
52 int shift = (uc_priv->gpio_count / BANKSIZE) - 1;
53
54 return dm_i2c_reg_clrset(dev, (reg << shift) | bank, mask, val ? mask : 0);
55 }
56
mcp230xx_get_value(struct udevice * dev,uint offset)57 static int mcp230xx_get_value(struct udevice *dev, uint offset)
58 {
59 int ret;
60
61 ret = mcp230xx_read(dev, MCP230XX_GPIO, offset);
62 if (ret < 0) {
63 dev_err(dev, "%s error: %d\n", __func__, ret);
64 return ret;
65 }
66
67 return ret;
68 }
69
mcp230xx_set_value(struct udevice * dev,uint offset,int val)70 static int mcp230xx_set_value(struct udevice *dev, uint offset, int val)
71 {
72 int ret;
73
74 ret = mcp230xx_write(dev, MCP230XX_GPIO, offset, val);
75 if (ret < 0) {
76 dev_err(dev, "%s error: %d\n", __func__, ret);
77 return ret;
78 }
79
80 return ret;
81 }
82
mcp230xx_get_flags(struct udevice * dev,unsigned int offset,ulong * flags)83 static int mcp230xx_get_flags(struct udevice *dev, unsigned int offset,
84 ulong *flags)
85 {
86 int direction, pullup;
87
88 pullup = mcp230xx_read(dev, MCP230XX_GPPU, offset);
89 if (pullup < 0) {
90 dev_err(dev, "%s error: %d\n", __func__, pullup);
91 return pullup;
92 }
93
94 direction = mcp230xx_read(dev, MCP230XX_IODIR, offset);
95 if (direction < 0) {
96 dev_err(dev, "%s error: %d\n", __func__, direction);
97 return direction;
98 }
99
100 *flags = direction ? GPIOD_IS_IN : GPIOD_IS_OUT;
101
102 if (pullup)
103 *flags |= GPIOD_PULL_UP;
104
105 return 0;
106 }
107
mcp230xx_set_flags(struct udevice * dev,uint offset,ulong flags)108 static int mcp230xx_set_flags(struct udevice *dev, uint offset, ulong flags)
109 {
110 bool input = !(flags & (GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE));
111 bool pullup = flags & GPIOD_PULL_UP;
112 ulong supported_mask;
113 int ret;
114
115 /* Note: active-low is ignored (handled by core) */
116 supported_mask = GPIOD_ACTIVE_LOW | GPIOD_MASK_DIR | GPIOD_PULL_UP;
117 if (flags & ~supported_mask) {
118 dev_err(dev, "%s unsupported flag(s): %lx\n", __func__, flags);
119 return -EINVAL;
120 }
121
122 ret = mcp230xx_write(dev, MCP230XX_OLAT, offset, !!(flags & GPIOD_IS_OUT_ACTIVE));
123 if (ret) {
124 dev_err(dev, "%s failed to setup output latch: %d\n", __func__, ret);
125 return ret;
126 }
127
128 ret = mcp230xx_write(dev, MCP230XX_GPPU, offset, pullup);
129 if (ret) {
130 dev_err(dev, "%s failed to setup pull-up: %d\n", __func__, ret);
131 return ret;
132 }
133
134 ret = mcp230xx_write(dev, MCP230XX_IODIR, offset, input);
135 if (ret) {
136 dev_err(dev, "%s failed to setup direction: %d\n", __func__, ret);
137 return ret;
138 }
139
140 return 0;
141 }
142
mcp230xx_direction_input(struct udevice * dev,uint offset)143 static int mcp230xx_direction_input(struct udevice *dev, uint offset)
144 {
145 return mcp230xx_set_flags(dev, offset, GPIOD_IS_IN);
146 }
147
mcp230xx_direction_output(struct udevice * dev,uint offset,int val)148 static int mcp230xx_direction_output(struct udevice *dev, uint offset, int val)
149 {
150 int ret = mcp230xx_set_value(dev, offset, val);
151 if (ret < 0) {
152 dev_err(dev, "%s error: %d\n", __func__, ret);
153 return ret;
154 }
155 return mcp230xx_set_flags(dev, offset, GPIOD_IS_OUT);
156 }
157
mcp230xx_get_function(struct udevice * dev,uint offset)158 static int mcp230xx_get_function(struct udevice *dev, uint offset)
159 {
160 int ret;
161
162 ret = mcp230xx_read(dev, MCP230XX_IODIR, offset);
163 if (ret < 0) {
164 dev_err(dev, "%s error: %d\n", __func__, ret);
165 return ret;
166 }
167
168 return ret ? GPIOF_INPUT : GPIOF_OUTPUT;
169 }
170
171 static const struct dm_gpio_ops mcp230xx_ops = {
172 .direction_input = mcp230xx_direction_input,
173 .direction_output = mcp230xx_direction_output,
174 .get_value = mcp230xx_get_value,
175 .set_value = mcp230xx_set_value,
176 .get_function = mcp230xx_get_function,
177 .set_flags = mcp230xx_set_flags,
178 .get_flags = mcp230xx_get_flags,
179 };
180
mcp230xx_probe(struct udevice * dev)181 static int mcp230xx_probe(struct udevice *dev)
182 {
183 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
184 char name[32], label[8], *str;
185 int addr, gpio_count, size;
186 const u8 *tmp;
187
188 switch (dev_get_driver_data(dev)) {
189 case MCP23008:
190 gpio_count = 8;
191 break;
192 case MCP23017:
193 case MCP23018:
194 gpio_count = 16;
195 break;
196 default:
197 return -ENODEV;
198 }
199
200 addr = dev_read_addr(dev);
201 tmp = dev_read_prop(dev, "label", &size);
202 if (tmp) {
203 memcpy(label, tmp, sizeof(label) - 1);
204 label[sizeof(label) - 1] = '\0';
205 snprintf(name, sizeof(name), "%s@%x_", label, addr);
206 } else {
207 snprintf(name, sizeof(name), "gpio@%x_", addr);
208 }
209
210 str = strdup(name);
211 if (!str)
212 return -ENOMEM;
213
214 uc_priv->bank_name = str;
215 uc_priv->gpio_count = gpio_count;
216
217 dev_dbg(dev, "%s is ready\n", str);
218
219 return 0;
220 }
221
222 static const struct udevice_id mcp230xx_ids[] = {
223 { .compatible = "microchip,mcp23008", .data = MCP23008, },
224 { .compatible = "microchip,mcp23017", .data = MCP23017, },
225 { .compatible = "microchip,mcp23018", .data = MCP23018, },
226 { }
227 };
228
229 U_BOOT_DRIVER(mcp230xx) = {
230 .name = "mcp230xx",
231 .id = UCLASS_GPIO,
232 .ops = &mcp230xx_ops,
233 .probe = mcp230xx_probe,
234 .of_match = mcp230xx_ids,
235 };
236