GNU Linux-libre 5.13.14-gnu1
[releases.git] / drivers / pinctrl / pinctrl-mcp23s08_spi.c
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);
94
95                 config = &mcp23x08_regmap;
96                 name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr);
97                 break;
98
99         case MCP_TYPE_S17:
100                 mcp->reg_shift = 1;
101                 mcp->chip.ngpio = 16;
102                 mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s17.%d", addr);
103
104                 config = &mcp23x17_regmap;
105                 name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr);
106                 break;
107
108         case MCP_TYPE_S18:
109                 mcp->reg_shift = 1;
110                 mcp->chip.ngpio = 16;
111                 mcp->chip.label = "mcp23s18";
112
113                 config = &mcp23x17_regmap;
114                 name = config->name;
115                 break;
116
117         default:
118                 dev_err(dev, "invalid device type (%d)\n", type);
119                 return -EINVAL;
120         }
121
122         copy = devm_kmemdup(dev, config, sizeof(*config), GFP_KERNEL);
123         if (!copy)
124                 return -ENOMEM;
125
126         copy->name = name;
127
128         mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp, copy);
129         if (IS_ERR(mcp->regmap))
130                 dev_err(dev, "regmap init failed for %s\n", mcp->chip.label);
131         return PTR_ERR_OR_ZERO(mcp->regmap);
132 }
133
134 static int mcp23s08_probe(struct spi_device *spi)
135 {
136         struct device *dev = &spi->dev;
137         struct mcp23s08_driver_data *data;
138         unsigned long spi_present_mask;
139         const void *match;
140         unsigned int addr;
141         unsigned int ngpio = 0;
142         int chips;
143         int type;
144         int ret;
145         u32 v;
146
147         match = device_get_match_data(dev);
148         if (match)
149                 type = (int)(uintptr_t)match;
150         else
151                 type = spi_get_device_id(spi)->driver_data;
152
153         ret = device_property_read_u32(dev, "microchip,spi-present-mask", &v);
154         if (ret) {
155                 ret = device_property_read_u32(dev, "mcp,spi-present-mask", &v);
156                 if (ret) {
157                         dev_err(dev, "missing spi-present-mask");
158                         return ret;
159                 }
160         }
161         spi_present_mask = v;
162
163         if (!spi_present_mask || spi_present_mask >= BIT(MCP_MAX_DEV_PER_CS)) {
164                 dev_err(dev, "invalid spi-present-mask");
165                 return -ENODEV;
166         }
167
168         chips = hweight_long(spi_present_mask);
169
170         data = devm_kzalloc(dev, struct_size(data, chip, chips), GFP_KERNEL);
171         if (!data)
172                 return -ENOMEM;
173
174         spi_set_drvdata(spi, data);
175
176         for_each_set_bit(addr, &spi_present_mask, MCP_MAX_DEV_PER_CS) {
177                 data->mcp[addr] = &data->chip[--chips];
178                 data->mcp[addr]->irq = spi->irq;
179
180                 ret = mcp23s08_spi_regmap_init(data->mcp[addr], dev, addr, type);
181                 if (ret)
182                         return ret;
183
184                 data->mcp[addr]->pinctrl_desc.name = devm_kasprintf(dev, GFP_KERNEL,
185                                                                     "mcp23xxx-pinctrl.%d",
186                                                                     addr);
187                 if (!data->mcp[addr]->pinctrl_desc.name)
188                         return -ENOMEM;
189
190                 ret = mcp23s08_probe_one(data->mcp[addr], dev, 0x40 | (addr << 1), type, -1);
191                 if (ret < 0)
192                         return ret;
193
194                 ngpio += data->mcp[addr]->chip.ngpio;
195         }
196         data->ngpio = ngpio;
197
198         return 0;
199 }
200
201 static const struct spi_device_id mcp23s08_ids[] = {
202         { "mcp23s08", MCP_TYPE_S08 },
203         { "mcp23s17", MCP_TYPE_S17 },
204         { "mcp23s18", MCP_TYPE_S18 },
205         { }
206 };
207 MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
208
209 static const struct of_device_id mcp23s08_spi_of_match[] = {
210         {
211                 .compatible = "microchip,mcp23s08",
212                 .data = (void *) MCP_TYPE_S08,
213         },
214         {
215                 .compatible = "microchip,mcp23s17",
216                 .data = (void *) MCP_TYPE_S17,
217         },
218         {
219                 .compatible = "microchip,mcp23s18",
220                 .data = (void *) MCP_TYPE_S18,
221         },
222 /* NOTE: The use of the mcp prefix is deprecated and will be removed. */
223         {
224                 .compatible = "mcp,mcp23s08",
225                 .data = (void *) MCP_TYPE_S08,
226         },
227         {
228                 .compatible = "mcp,mcp23s17",
229                 .data = (void *) MCP_TYPE_S17,
230         },
231         { }
232 };
233 MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match);
234
235 static struct spi_driver mcp23s08_driver = {
236         .probe          = mcp23s08_probe,
237         .id_table       = mcp23s08_ids,
238         .driver = {
239                 .name   = "mcp23s08",
240                 .of_match_table = mcp23s08_spi_of_match,
241         },
242 };
243
244 static int __init mcp23s08_spi_init(void)
245 {
246         return spi_register_driver(&mcp23s08_driver);
247 }
248
249 /*
250  * Register after SPI postcore initcall and before
251  * subsys initcalls that may rely on these GPIOs.
252  */
253 subsys_initcall(mcp23s08_spi_init);
254
255 static void mcp23s08_spi_exit(void)
256 {
257         spi_unregister_driver(&mcp23s08_driver);
258 }
259 module_exit(mcp23s08_spi_exit);
260
261 MODULE_LICENSE("GPL");