// SPDX-License-Identifier: GPL-2.0-only /* MCP23S08 SPI GPIO driver */ #include #include #include #include #include #include "pinctrl-mcp23s08.h" #define MCP_MAX_DEV_PER_CS 8 /* * A given spi_device can represent up to eight mcp23sxx chips * sharing the same chipselect but using different addresses * (e.g. chips #0 and #3 might be populated, but not #1 or #2). * Driver data holds all the per-chip data. */ struct mcp23s08_driver_data { unsigned ngpio; struct mcp23s08 *mcp[8]; struct mcp23s08 chip[]; }; static int mcp23sxx_spi_write(void *context, const void *data, size_t count) { struct mcp23s08 *mcp = context; struct spi_device *spi = to_spi_device(mcp->dev); struct spi_message m; struct spi_transfer t[2] = { { .tx_buf = &mcp->addr, .len = 1, }, { .tx_buf = data, .len = count, }, }; spi_message_init(&m); spi_message_add_tail(&t[0], &m); spi_message_add_tail(&t[1], &m); return spi_sync(spi, &m); } static int mcp23sxx_spi_gather_write(void *context, const void *reg, size_t reg_size, const void *val, size_t val_size) { struct mcp23s08 *mcp = context; struct spi_device *spi = to_spi_device(mcp->dev); struct spi_message m; struct spi_transfer t[3] = { { .tx_buf = &mcp->addr, .len = 1, }, { .tx_buf = reg, .len = reg_size, }, { .tx_buf = val, .len = val_size, }, }; spi_message_init(&m); spi_message_add_tail(&t[0], &m); spi_message_add_tail(&t[1], &m); spi_message_add_tail(&t[2], &m); return spi_sync(spi, &m); } static int mcp23sxx_spi_read(void *context, const void *reg, size_t reg_size, void *val, size_t val_size) { struct mcp23s08 *mcp = context; struct spi_device *spi = to_spi_device(mcp->dev); u8 tx[2]; if (reg_size != 1) return -EINVAL; tx[0] = mcp->addr | 0x01; tx[1] = *((u8 *) reg); return spi_write_then_read(spi, tx, sizeof(tx), val, val_size); } static const struct regmap_bus mcp23sxx_spi_regmap = { .write = mcp23sxx_spi_write, .gather_write = mcp23sxx_spi_gather_write, .read = mcp23sxx_spi_read, }; static int mcp23s08_spi_regmap_init(struct mcp23s08 *mcp, struct device *dev, unsigned int addr, const struct mcp23s08_info *info) { struct regmap_config *copy; const char *name; switch (info->type) { case MCP_TYPE_S08: mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s08.%d", addr); if (!mcp->chip.label) return -ENOMEM; name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr); if (!name) return -ENOMEM; break; case MCP_TYPE_S17: mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s17.%d", addr); if (!mcp->chip.label) return -ENOMEM; name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr); if (!name) return -ENOMEM; break; case MCP_TYPE_S18: mcp->chip.label = info->label; name = info->regmap->name; break; default: dev_err(dev, "invalid device type (%d)\n", info->type); return -EINVAL; } mcp->reg_shift = info->reg_shift; mcp->chip.ngpio = info->ngpio; copy = devm_kmemdup(dev, info->regmap, sizeof(*info->regmap), GFP_KERNEL); if (!copy) return -ENOMEM; copy->name = name; mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp, copy); if (IS_ERR(mcp->regmap)) dev_err(dev, "regmap init failed for %s\n", mcp->chip.label); return PTR_ERR_OR_ZERO(mcp->regmap); } static int mcp23s08_probe(struct spi_device *spi) { struct mcp23s08_driver_data *data; const struct mcp23s08_info *info; struct device *dev = &spi->dev; unsigned long spi_present_mask; unsigned int ngpio = 0; unsigned int addr; int chips; int ret; u32 v; info = spi_get_device_match_data(spi); ret = device_property_read_u32(dev, "microchip,spi-present-mask", &v); if (ret) { ret = device_property_read_u32(dev, "mcp,spi-present-mask", &v); if (ret) { dev_err(dev, "missing spi-present-mask"); return ret; } } spi_present_mask = v; if (!spi_present_mask || spi_present_mask >= BIT(MCP_MAX_DEV_PER_CS)) { dev_err(dev, "invalid spi-present-mask"); return -ENODEV; } chips = hweight_long(spi_present_mask); data = devm_kzalloc(dev, struct_size(data, chip, chips), GFP_KERNEL); if (!data) return -ENOMEM; spi_set_drvdata(spi, data); for_each_set_bit(addr, &spi_present_mask, MCP_MAX_DEV_PER_CS) { data->mcp[addr] = &data->chip[--chips]; data->mcp[addr]->irq = spi->irq; ret = mcp23s08_spi_regmap_init(data->mcp[addr], dev, addr, info); if (ret) return ret; data->mcp[addr]->pinctrl_desc.name = devm_kasprintf(dev, GFP_KERNEL, "mcp23xxx-pinctrl.%d", addr); if (!data->mcp[addr]->pinctrl_desc.name) return -ENOMEM; ret = mcp23s08_probe_one(data->mcp[addr], dev, 0x40 | (addr << 1), info->type, -1); if (ret < 0) return ret; ngpio += data->mcp[addr]->chip.ngpio; } data->ngpio = ngpio; return 0; } static const struct mcp23s08_info mcp23s08_spi = { .regmap = &mcp23x08_regmap, .type = MCP_TYPE_S08, .ngpio = 8, .reg_shift = 0, }; static const struct mcp23s08_info mcp23s17_spi = { .regmap = &mcp23x17_regmap, .type = MCP_TYPE_S17, .ngpio = 16, .reg_shift = 1, }; static const struct mcp23s08_info mcp23s18_spi = { .regmap = &mcp23x17_regmap, .label = "mcp23s18", .type = MCP_TYPE_S18, .ngpio = 16, .reg_shift = 1, }; static const struct spi_device_id mcp23s08_ids[] = { { "mcp23s08", (kernel_ulong_t)&mcp23s08_spi }, { "mcp23s17", (kernel_ulong_t)&mcp23s17_spi }, { "mcp23s18", (kernel_ulong_t)&mcp23s18_spi }, { } }; MODULE_DEVICE_TABLE(spi, mcp23s08_ids); static const struct of_device_id mcp23s08_spi_of_match[] = { { .compatible = "microchip,mcp23s08", .data = &mcp23s08_spi }, { .compatible = "microchip,mcp23s17", .data = &mcp23s17_spi }, { .compatible = "microchip,mcp23s18", .data = &mcp23s18_spi }, /* NOTE: The use of the mcp prefix is deprecated and will be removed. */ { .compatible = "mcp,mcp23s08", .data = &mcp23s08_spi }, { .compatible = "mcp,mcp23s17", .data = &mcp23s17_spi }, { } }; MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match); static struct spi_driver mcp23s08_driver = { .probe = mcp23s08_probe, .id_table = mcp23s08_ids, .driver = { .name = "mcp23s08", .of_match_table = mcp23s08_spi_of_match, }, }; static int __init mcp23s08_spi_init(void) { return spi_register_driver(&mcp23s08_driver); } /* * Register after SPI postcore initcall and before * subsys initcalls that may rely on these GPIOs. */ subsys_initcall(mcp23s08_spi_init); static void mcp23s08_spi_exit(void) { spi_unregister_driver(&mcp23s08_driver); } module_exit(mcp23s08_spi_exit); MODULE_LICENSE("GPL");