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, 84 const struct mcp23s08_info *info) 85 { 86 struct regmap_config *copy; 87 const char *name; 88 89 switch (info->type) { 90 case MCP_TYPE_S08: 91 mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s08.%d", addr); 92 if (!mcp->chip.label) 93 return -ENOMEM; 94 95 name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr); 96 if (!name) 97 return -ENOMEM; 98 99 break; 100 101 case MCP_TYPE_S17: 102 mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s17.%d", addr); 103 if (!mcp->chip.label) 104 return -ENOMEM; 105 106 name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr); 107 if (!name) 108 return -ENOMEM; 109 110 break; 111 112 case MCP_TYPE_S18: 113 mcp->chip.label = info->label; 114 name = info->regmap->name; 115 break; 116 117 default: 118 dev_err(dev, "invalid device type (%d)\n", info->type); 119 return -EINVAL; 120 } 121 122 mcp->reg_shift = info->reg_shift; 123 mcp->chip.ngpio = info->ngpio; 124 copy = devm_kmemdup(dev, info->regmap, sizeof(*info->regmap), GFP_KERNEL); 125 if (!copy) 126 return -ENOMEM; 127 128 copy->name = name; 129 130 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); 134 } 135 136 static int mcp23s08_probe(struct spi_device *spi) 137 { 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; 143 unsigned int addr; 144 int chips; 145 int ret; 146 u32 v; 147 148 info = spi_get_device_match_data(spi); 149 150 ret = device_property_read_u32(dev, "microchip,spi-present-mask", &v); 151 if (ret) { 152 ret = device_property_read_u32(dev, "mcp,spi-present-mask", &v); 153 if (ret) { 154 dev_err(dev, "missing spi-present-mask"); 155 return ret; 156 } 157 } 158 spi_present_mask = v; 159 160 if (!spi_present_mask || spi_present_mask >= BIT(MCP_MAX_DEV_PER_CS)) { 161 dev_err(dev, "invalid spi-present-mask"); 162 return -ENODEV; 163 } 164 165 chips = hweight_long(spi_present_mask); 166 167 data = devm_kzalloc(dev, struct_size(data, chip, chips), GFP_KERNEL); 168 if (!data) 169 return -ENOMEM; 170 171 spi_set_drvdata(spi, data); 172 173 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; 176 177 ret = mcp23s08_spi_regmap_init(data->mcp[addr], dev, addr, info); 178 if (ret) 179 return ret; 180 181 data->mcp[addr]->pinctrl_desc.name = devm_kasprintf(dev, GFP_KERNEL, 182 "mcp23xxx-pinctrl.%d", 183 addr); 184 if (!data->mcp[addr]->pinctrl_desc.name) 185 return -ENOMEM; 186 187 ret = mcp23s08_probe_one(data->mcp[addr], dev, 0x40 | (addr << 1), 188 info->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 } 198 199 static const struct mcp23s08_info mcp23s08_spi = { 200 .regmap = &mcp23x08_regmap, 201 .type = MCP_TYPE_S08, 202 .ngpio = 8, 203 .reg_shift = 0, 204 }; 205 206 static const struct mcp23s08_info mcp23s17_spi = { 207 .regmap = &mcp23x17_regmap, 208 .type = MCP_TYPE_S17, 209 .ngpio = 16, 210 .reg_shift = 1, 211 }; 212 213 static const struct mcp23s08_info mcp23s18_spi = { 214 .regmap = &mcp23x17_regmap, 215 .label = "mcp23s18", 216 .type = MCP_TYPE_S18, 217 .ngpio = 16, 218 .reg_shift = 1, 219 }; 220 221 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 }, 225 { } 226 }; 227 MODULE_DEVICE_TABLE(spi, mcp23s08_ids); 228 229 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 }, 236 { } 237 }; 238 MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match); 239 240 static struct spi_driver mcp23s08_driver = { 241 .probe = mcp23s08_probe, 242 .id_table = mcp23s08_ids, 243 .driver = { 244 .name = "mcp23s08", 245 .of_match_table = mcp23s08_spi_of_match, 246 }, 247 }; 248 249 static int __init mcp23s08_spi_init(void) 250 { 251 return spi_register_driver(&mcp23s08_driver); 252 } 253 254 /* 255 * Register after SPI postcore initcall and before 256 * subsys initcalls that may rely on these GPIOs. 257 */ 258 subsys_initcall(mcp23s08_spi_init); 259 260 static void mcp23s08_spi_exit(void) 261 { 262 spi_unregister_driver(&mcp23s08_driver); 263 } 264 module_exit(mcp23s08_spi_exit); 265 266 MODULE_DESCRIPTION("MCP23S08 SPI GPIO driver"); 267 MODULE_LICENSE("GPL"); 268