1
2
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
16
17
18
19
20struct mcp23s08_driver_data {
21 unsigned ngpio;
22 struct mcp23s08 *mcp[8];
23 struct mcp23s08 chip[];
24};
25
26static 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
41static 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
60static 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
76static 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
82static 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 return PTR_ERR_OR_ZERO(mcp->regmap);
130}
131
132static int mcp23s08_probe(struct spi_device *spi)
133{
134 struct device *dev = &spi->dev;
135 struct mcp23s08_driver_data *data;
136 unsigned long spi_present_mask;
137 const void *match;
138 unsigned int addr;
139 unsigned int ngpio = 0;
140 int chips;
141 int type;
142 int ret;
143 u32 v;
144
145 match = device_get_match_data(dev);
146 if (match)
147 type = (int)(uintptr_t)match;
148 else
149 type = spi_get_device_id(spi)->driver_data;
150
151 ret = device_property_read_u32(dev, "microchip,spi-present-mask", &v);
152 if (ret) {
153 ret = device_property_read_u32(dev, "mcp,spi-present-mask", &v);
154 if (ret) {
155 dev_err(dev, "missing spi-present-mask");
156 return ret;
157 }
158 }
159 spi_present_mask = v;
160
161 if (!spi_present_mask || spi_present_mask >= BIT(MCP_MAX_DEV_PER_CS)) {
162 dev_err(dev, "invalid spi-present-mask");
163 return -ENODEV;
164 }
165
166 chips = hweight_long(spi_present_mask);
167
168 data = devm_kzalloc(dev, struct_size(data, chip, chips), GFP_KERNEL);
169 if (!data)
170 return -ENOMEM;
171
172 spi_set_drvdata(spi, data);
173
174 for_each_set_bit(addr, &spi_present_mask, MCP_MAX_DEV_PER_CS) {
175 data->mcp[addr] = &data->chip[--chips];
176 data->mcp[addr]->irq = spi->irq;
177
178 ret = mcp23s08_spi_regmap_init(data->mcp[addr], dev, addr, type);
179 if (ret)
180 return ret;
181
182 data->mcp[addr]->pinctrl_desc.name = devm_kasprintf(dev, GFP_KERNEL,
183 "mcp23xxx-pinctrl.%d",
184 addr);
185 if (!data->mcp[addr]->pinctrl_desc.name)
186 return -ENOMEM;
187
188 ret = mcp23s08_probe_one(data->mcp[addr], dev, 0x40 | (addr << 1), type, -1);
189 if (ret < 0)
190 return ret;
191
192 ngpio += data->mcp[addr]->chip.ngpio;
193 }
194 data->ngpio = ngpio;
195
196 return 0;
197}
198
199static const struct spi_device_id mcp23s08_ids[] = {
200 { "mcp23s08", MCP_TYPE_S08 },
201 { "mcp23s17", MCP_TYPE_S17 },
202 { "mcp23s18", MCP_TYPE_S18 },
203 { }
204};
205MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
206
207static const struct of_device_id mcp23s08_spi_of_match[] = {
208 {
209 .compatible = "microchip,mcp23s08",
210 .data = (void *) MCP_TYPE_S08,
211 },
212 {
213 .compatible = "microchip,mcp23s17",
214 .data = (void *) MCP_TYPE_S17,
215 },
216 {
217 .compatible = "microchip,mcp23s18",
218 .data = (void *) MCP_TYPE_S18,
219 },
220
221 {
222 .compatible = "mcp,mcp23s08",
223 .data = (void *) MCP_TYPE_S08,
224 },
225 {
226 .compatible = "mcp,mcp23s17",
227 .data = (void *) MCP_TYPE_S17,
228 },
229 { }
230};
231MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match);
232
233static struct spi_driver mcp23s08_driver = {
234 .probe = mcp23s08_probe,
235 .id_table = mcp23s08_ids,
236 .driver = {
237 .name = "mcp23s08",
238 .of_match_table = mcp23s08_spi_of_match,
239 },
240};
241
242static int __init mcp23s08_spi_init(void)
243{
244 return spi_register_driver(&mcp23s08_driver);
245}
246
247
248
249
250
251subsys_initcall(mcp23s08_spi_init);
252
253static void mcp23s08_spi_exit(void)
254{
255 spi_unregister_driver(&mcp23s08_driver);
256}
257module_exit(mcp23s08_spi_exit);
258
259MODULE_LICENSE("GPL");
260