1 // SPDX-License-Identifier: GPL-2.0-only
2 /* MCP23S08 SPI GPIO driver */
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>
10 #include "pinctrl-mcp23s08.h"
12 #define MCP_MAX_DEV_PER_CS 8
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.
20 struct mcp23s08_driver_data {
22 struct mcp23s08 *mcp[8];
23 struct mcp23s08 chip[];
26 static int mcp23sxx_spi_write(void *context, const void *data, size_t count)
28 struct mcp23s08 *mcp = context;
29 struct spi_device *spi = to_spi_device(mcp->dev);
31 struct spi_transfer t[2] = { { .tx_buf = &mcp->addr, .len = 1, },
32 { .tx_buf = data, .len = count, }, };
35 spi_message_add_tail(&t[0], &m);
36 spi_message_add_tail(&t[1], &m);
38 return spi_sync(spi, &m);
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)
45 struct mcp23s08 *mcp = context;
46 struct spi_device *spi = to_spi_device(mcp->dev);
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, }, };
53 spi_message_add_tail(&t[0], &m);
54 spi_message_add_tail(&t[1], &m);
55 spi_message_add_tail(&t[2], &m);
57 return spi_sync(spi, &m);
60 static int mcp23sxx_spi_read(void *context, const void *reg, size_t reg_size,
61 void *val, size_t val_size)
63 struct mcp23s08 *mcp = context;
64 struct spi_device *spi = to_spi_device(mcp->dev);
70 tx[0] = mcp->addr | 0x01;
71 tx[1] = *((u8 *) reg);
73 return spi_write_then_read(spi, tx, sizeof(tx), val, val_size);
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,
82 static int mcp23s08_spi_regmap_init(struct mcp23s08 *mcp, struct device *dev,
84 const struct mcp23s08_info *info)
86 struct regmap_config *copy;
91 mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s08.%d", addr);
95 name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr);
102 mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s17.%d", addr);
103 if (!mcp->chip.label)
106 name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr);
113 mcp->chip.label = info->label;
114 name = info->regmap->name;
118 dev_err(dev, "invalid device type (%d)\n", info->type);
122 mcp->reg_shift = info->reg_shift;
123 mcp->chip.ngpio = info->ngpio;
124 copy = devm_kmemdup(dev, info->regmap, sizeof(*info->regmap), GFP_KERNEL);
130 mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp, copy);
131 if (IS_ERR(mcp->regmap))
132 dev_err(dev, "regmap init failed for %s\n", mcp->chip.label);
133 return PTR_ERR_OR_ZERO(mcp->regmap);
136 static int mcp23s08_probe(struct spi_device *spi)
138 struct mcp23s08_driver_data *data;
139 const struct mcp23s08_info *info;
140 struct device *dev = &spi->dev;
141 unsigned long spi_present_mask;
142 unsigned int ngpio = 0;
148 info = spi_get_device_match_data(spi);
150 ret = device_property_read_u32(dev, "microchip,spi-present-mask", &v);
152 ret = device_property_read_u32(dev, "mcp,spi-present-mask", &v);
154 dev_err(dev, "missing spi-present-mask");
158 spi_present_mask = v;
160 if (!spi_present_mask || spi_present_mask >= BIT(MCP_MAX_DEV_PER_CS)) {
161 dev_err(dev, "invalid spi-present-mask");
165 chips = hweight_long(spi_present_mask);
167 data = devm_kzalloc(dev, struct_size(data, chip, chips), GFP_KERNEL);
171 spi_set_drvdata(spi, data);
173 for_each_set_bit(addr, &spi_present_mask, MCP_MAX_DEV_PER_CS) {
174 data->mcp[addr] = &data->chip[--chips];
175 data->mcp[addr]->irq = spi->irq;
177 ret = mcp23s08_spi_regmap_init(data->mcp[addr], dev, addr, info);
181 data->mcp[addr]->pinctrl_desc.name = devm_kasprintf(dev, GFP_KERNEL,
182 "mcp23xxx-pinctrl.%d",
184 if (!data->mcp[addr]->pinctrl_desc.name)
187 ret = mcp23s08_probe_one(data->mcp[addr], dev, 0x40 | (addr << 1),
192 ngpio += data->mcp[addr]->chip.ngpio;
199 static const struct mcp23s08_info mcp23s08_spi = {
200 .regmap = &mcp23x08_regmap,
201 .type = MCP_TYPE_S08,
206 static const struct mcp23s08_info mcp23s17_spi = {
207 .regmap = &mcp23x17_regmap,
208 .type = MCP_TYPE_S17,
213 static const struct mcp23s08_info mcp23s18_spi = {
214 .regmap = &mcp23x17_regmap,
216 .type = MCP_TYPE_S18,
221 static const struct spi_device_id mcp23s08_ids[] = {
222 { "mcp23s08", (kernel_ulong_t)&mcp23s08_spi },
223 { "mcp23s17", (kernel_ulong_t)&mcp23s17_spi },
224 { "mcp23s18", (kernel_ulong_t)&mcp23s18_spi },
227 MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
229 static const struct of_device_id mcp23s08_spi_of_match[] = {
230 { .compatible = "microchip,mcp23s08", .data = &mcp23s08_spi },
231 { .compatible = "microchip,mcp23s17", .data = &mcp23s17_spi },
232 { .compatible = "microchip,mcp23s18", .data = &mcp23s18_spi },
233 /* NOTE: The use of the mcp prefix is deprecated and will be removed. */
234 { .compatible = "mcp,mcp23s08", .data = &mcp23s08_spi },
235 { .compatible = "mcp,mcp23s17", .data = &mcp23s17_spi },
238 MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match);
240 static struct spi_driver mcp23s08_driver = {
241 .probe = mcp23s08_probe,
242 .id_table = mcp23s08_ids,
245 .of_match_table = mcp23s08_spi_of_match,
249 static int __init mcp23s08_spi_init(void)
251 return spi_register_driver(&mcp23s08_driver);
255 * Register after SPI postcore initcall and before
256 * subsys initcalls that may rely on these GPIOs.
258 subsys_initcall(mcp23s08_spi_init);
260 static void mcp23s08_spi_exit(void)
262 spi_unregister_driver(&mcp23s08_driver);
264 module_exit(mcp23s08_spi_exit);
266 MODULE_LICENSE("GPL");