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"); 262