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0f04a817 AS |
1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* MCP23S08 SPI GPIO driver */ | |
3 | ||
4 | #include <linux/mod_devicetable.h> | |
5 | #include <linux/module.h> | |
6 | #include <linux/property.h> | |
7 | #include <linux/regmap.h> | |
8 | #include <linux/spi/spi.h> | |
9 | ||
10 | #include "pinctrl-mcp23s08.h" | |
11 | ||
12 | #define MCP_MAX_DEV_PER_CS 8 | |
13 | ||
14 | /* | |
15 | * A given spi_device can represent up to eight mcp23sxx chips | |
16 | * sharing the same chipselect but using different addresses | |
17 | * (e.g. chips #0 and #3 might be populated, but not #1 or #2). | |
18 | * Driver data holds all the per-chip data. | |
19 | */ | |
20 | struct mcp23s08_driver_data { | |
21 | unsigned ngpio; | |
22 | struct mcp23s08 *mcp[8]; | |
23 | struct mcp23s08 chip[]; | |
24 | }; | |
25 | ||
26 | static int mcp23sxx_spi_write(void *context, const void *data, size_t count) | |
27 | { | |
28 | struct mcp23s08 *mcp = context; | |
29 | struct spi_device *spi = to_spi_device(mcp->dev); | |
30 | struct spi_message m; | |
31 | struct spi_transfer t[2] = { { .tx_buf = &mcp->addr, .len = 1, }, | |
32 | { .tx_buf = data, .len = count, }, }; | |
33 | ||
34 | spi_message_init(&m); | |
35 | spi_message_add_tail(&t[0], &m); | |
36 | spi_message_add_tail(&t[1], &m); | |
37 | ||
38 | return spi_sync(spi, &m); | |
39 | } | |
40 | ||
41 | static int mcp23sxx_spi_gather_write(void *context, | |
42 | const void *reg, size_t reg_size, | |
43 | const void *val, size_t val_size) | |
44 | { | |
45 | struct mcp23s08 *mcp = context; | |
46 | struct spi_device *spi = to_spi_device(mcp->dev); | |
47 | struct spi_message m; | |
48 | struct spi_transfer t[3] = { { .tx_buf = &mcp->addr, .len = 1, }, | |
49 | { .tx_buf = reg, .len = reg_size, }, | |
50 | { .tx_buf = val, .len = val_size, }, }; | |
51 | ||
52 | spi_message_init(&m); | |
53 | spi_message_add_tail(&t[0], &m); | |
54 | spi_message_add_tail(&t[1], &m); | |
55 | spi_message_add_tail(&t[2], &m); | |
56 | ||
57 | return spi_sync(spi, &m); | |
58 | } | |
59 | ||
60 | static int mcp23sxx_spi_read(void *context, const void *reg, size_t reg_size, | |
61 | void *val, size_t val_size) | |
62 | { | |
63 | struct mcp23s08 *mcp = context; | |
64 | struct spi_device *spi = to_spi_device(mcp->dev); | |
65 | u8 tx[2]; | |
66 | ||
67 | if (reg_size != 1) | |
68 | return -EINVAL; | |
69 | ||
70 | tx[0] = mcp->addr | 0x01; | |
71 | tx[1] = *((u8 *) reg); | |
72 | ||
73 | return spi_write_then_read(spi, tx, sizeof(tx), val, val_size); | |
74 | } | |
75 | ||
76 | static const struct regmap_bus mcp23sxx_spi_regmap = { | |
77 | .write = mcp23sxx_spi_write, | |
78 | .gather_write = mcp23sxx_spi_gather_write, | |
79 | .read = mcp23sxx_spi_read, | |
80 | }; | |
81 | ||
82 | static int mcp23s08_spi_regmap_init(struct mcp23s08 *mcp, struct device *dev, | |
83 | unsigned int addr, unsigned int type) | |
84 | { | |
85 | const struct regmap_config *config; | |
86 | struct regmap_config *copy; | |
87 | const char *name; | |
88 | ||
89 | switch (type) { | |
90 | case MCP_TYPE_S08: | |
91 | mcp->reg_shift = 0; | |
92 | mcp->chip.ngpio = 8; | |
93 | mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s08.%d", addr); | |
f941714a CB |
94 | if (!mcp->chip.label) |
95 | return -ENOMEM; | |
0f04a817 AS |
96 | |
97 | config = &mcp23x08_regmap; | |
98 | name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr); | |
f941714a CB |
99 | if (!name) |
100 | return -ENOMEM; | |
101 | ||
0f04a817 AS |
102 | break; |
103 | ||
104 | case MCP_TYPE_S17: | |
105 | mcp->reg_shift = 1; | |
106 | mcp->chip.ngpio = 16; | |
107 | mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s17.%d", addr); | |
f941714a CB |
108 | if (!mcp->chip.label) |
109 | return -ENOMEM; | |
0f04a817 AS |
110 | |
111 | config = &mcp23x17_regmap; | |
112 | name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr); | |
f941714a CB |
113 | if (!name) |
114 | return -ENOMEM; | |
115 | ||
0f04a817 AS |
116 | break; |
117 | ||
118 | case MCP_TYPE_S18: | |
119 | mcp->reg_shift = 1; | |
120 | mcp->chip.ngpio = 16; | |
121 | mcp->chip.label = "mcp23s18"; | |
122 | ||
123 | config = &mcp23x17_regmap; | |
124 | name = config->name; | |
125 | break; | |
126 | ||
127 | default: | |
128 | dev_err(dev, "invalid device type (%d)\n", type); | |
129 | return -EINVAL; | |
130 | } | |
131 | ||
2b12c136 | 132 | copy = devm_kmemdup(dev, config, sizeof(*config), GFP_KERNEL); |
0f04a817 AS |
133 | if (!copy) |
134 | return -ENOMEM; | |
135 | ||
136 | copy->name = name; | |
137 | ||
138 | mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp, copy); | |
a835d3a1 AS |
139 | if (IS_ERR(mcp->regmap)) |
140 | dev_err(dev, "regmap init failed for %s\n", mcp->chip.label); | |
3e5b8f87 | 141 | return PTR_ERR_OR_ZERO(mcp->regmap); |
0f04a817 AS |
142 | } |
143 | ||
144 | static int mcp23s08_probe(struct spi_device *spi) | |
145 | { | |
146 | struct device *dev = &spi->dev; | |
147 | struct mcp23s08_driver_data *data; | |
148 | unsigned long spi_present_mask; | |
149 | const void *match; | |
150 | unsigned int addr; | |
151 | unsigned int ngpio = 0; | |
152 | int chips; | |
153 | int type; | |
154 | int ret; | |
155 | u32 v; | |
156 | ||
157 | match = device_get_match_data(dev); | |
158 | if (match) | |
159 | type = (int)(uintptr_t)match; | |
160 | else | |
161 | type = spi_get_device_id(spi)->driver_data; | |
162 | ||
163 | ret = device_property_read_u32(dev, "microchip,spi-present-mask", &v); | |
164 | if (ret) { | |
165 | ret = device_property_read_u32(dev, "mcp,spi-present-mask", &v); | |
166 | if (ret) { | |
167 | dev_err(dev, "missing spi-present-mask"); | |
168 | return ret; | |
169 | } | |
170 | } | |
171 | spi_present_mask = v; | |
172 | ||
173 | if (!spi_present_mask || spi_present_mask >= BIT(MCP_MAX_DEV_PER_CS)) { | |
174 | dev_err(dev, "invalid spi-present-mask"); | |
175 | return -ENODEV; | |
176 | } | |
177 | ||
178 | chips = hweight_long(spi_present_mask); | |
179 | ||
180 | data = devm_kzalloc(dev, struct_size(data, chip, chips), GFP_KERNEL); | |
181 | if (!data) | |
182 | return -ENOMEM; | |
183 | ||
184 | spi_set_drvdata(spi, data); | |
185 | ||
186 | for_each_set_bit(addr, &spi_present_mask, MCP_MAX_DEV_PER_CS) { | |
187 | data->mcp[addr] = &data->chip[--chips]; | |
188 | data->mcp[addr]->irq = spi->irq; | |
189 | ||
190 | ret = mcp23s08_spi_regmap_init(data->mcp[addr], dev, addr, type); | |
191 | if (ret) | |
192 | return ret; | |
193 | ||
194 | data->mcp[addr]->pinctrl_desc.name = devm_kasprintf(dev, GFP_KERNEL, | |
195 | "mcp23xxx-pinctrl.%d", | |
196 | addr); | |
197 | if (!data->mcp[addr]->pinctrl_desc.name) | |
198 | return -ENOMEM; | |
199 | ||
200 | ret = mcp23s08_probe_one(data->mcp[addr], dev, 0x40 | (addr << 1), type, -1); | |
201 | if (ret < 0) | |
202 | return ret; | |
203 | ||
204 | ngpio += data->mcp[addr]->chip.ngpio; | |
205 | } | |
206 | data->ngpio = ngpio; | |
207 | ||
208 | return 0; | |
209 | } | |
210 | ||
211 | static const struct spi_device_id mcp23s08_ids[] = { | |
212 | { "mcp23s08", MCP_TYPE_S08 }, | |
213 | { "mcp23s17", MCP_TYPE_S17 }, | |
214 | { "mcp23s18", MCP_TYPE_S18 }, | |
215 | { } | |
216 | }; | |
217 | MODULE_DEVICE_TABLE(spi, mcp23s08_ids); | |
218 | ||
219 | static const struct of_device_id mcp23s08_spi_of_match[] = { | |
220 | { | |
221 | .compatible = "microchip,mcp23s08", | |
222 | .data = (void *) MCP_TYPE_S08, | |
223 | }, | |
224 | { | |
225 | .compatible = "microchip,mcp23s17", | |
226 | .data = (void *) MCP_TYPE_S17, | |
227 | }, | |
228 | { | |
229 | .compatible = "microchip,mcp23s18", | |
230 | .data = (void *) MCP_TYPE_S18, | |
231 | }, | |
232 | /* NOTE: The use of the mcp prefix is deprecated and will be removed. */ | |
233 | { | |
234 | .compatible = "mcp,mcp23s08", | |
235 | .data = (void *) MCP_TYPE_S08, | |
236 | }, | |
237 | { | |
238 | .compatible = "mcp,mcp23s17", | |
239 | .data = (void *) MCP_TYPE_S17, | |
240 | }, | |
241 | { } | |
242 | }; | |
243 | MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match); | |
244 | ||
245 | static struct spi_driver mcp23s08_driver = { | |
246 | .probe = mcp23s08_probe, | |
247 | .id_table = mcp23s08_ids, | |
248 | .driver = { | |
249 | .name = "mcp23s08", | |
250 | .of_match_table = mcp23s08_spi_of_match, | |
251 | }, | |
252 | }; | |
253 | ||
254 | static int __init mcp23s08_spi_init(void) | |
255 | { | |
256 | return spi_register_driver(&mcp23s08_driver); | |
257 | } | |
258 | ||
259 | /* | |
260 | * Register after SPI postcore initcall and before | |
261 | * subsys initcalls that may rely on these GPIOs. | |
262 | */ | |
263 | subsys_initcall(mcp23s08_spi_init); | |
264 | ||
265 | static void mcp23s08_spi_exit(void) | |
266 | { | |
267 | spi_unregister_driver(&mcp23s08_driver); | |
268 | } | |
269 | module_exit(mcp23s08_spi_exit); | |
270 | ||
271 | MODULE_LICENSE("GPL"); |