diff options
Diffstat (limited to 'drivers/pinctrl/pinctrl-mcp23s08_spi.c')
| -rw-r--r-- | drivers/pinctrl/pinctrl-mcp23s08_spi.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinctrl-mcp23s08_spi.c b/drivers/pinctrl/pinctrl-mcp23s08_spi.c new file mode 100644 index 000000000..ea059b9c5 --- /dev/null +++ b/drivers/pinctrl/pinctrl-mcp23s08_spi.c @@ -0,0 +1,271 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* MCP23S08 SPI GPIO driver */ + +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/property.h> +#include <linux/regmap.h> +#include <linux/spi/spi.h> + +#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, unsigned int type) +{ + const struct regmap_config *config; + struct regmap_config *copy; + const char *name; + + switch (type) { + case MCP_TYPE_S08: + mcp->reg_shift = 0; + mcp->chip.ngpio = 8; + mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s08.%d", addr); + if (!mcp->chip.label) + return -ENOMEM; + + config = &mcp23x08_regmap; + name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr); + if (!name) + return -ENOMEM; + + break; + + case MCP_TYPE_S17: + mcp->reg_shift = 1; + mcp->chip.ngpio = 16; + mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s17.%d", addr); + if (!mcp->chip.label) + return -ENOMEM; + + config = &mcp23x17_regmap; + name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr); + if (!name) + return -ENOMEM; + + break; + + case MCP_TYPE_S18: + mcp->reg_shift = 1; + mcp->chip.ngpio = 16; + mcp->chip.label = "mcp23s18"; + + config = &mcp23x17_regmap; + name = config->name; + break; + + default: + dev_err(dev, "invalid device type (%d)\n", type); + return -EINVAL; + } + + copy = devm_kmemdup(dev, config, sizeof(*config), 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 device *dev = &spi->dev; + struct mcp23s08_driver_data *data; + unsigned long spi_present_mask; + const void *match; + unsigned int addr; + unsigned int ngpio = 0; + int chips; + int type; + int ret; + u32 v; + + match = device_get_match_data(dev); + if (match) + type = (int)(uintptr_t)match; + else + type = spi_get_device_id(spi)->driver_data; + + 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, type); + 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), type, -1); + if (ret < 0) + return ret; + + ngpio += data->mcp[addr]->chip.ngpio; + } + data->ngpio = ngpio; + + return 0; +} + +static const struct spi_device_id mcp23s08_ids[] = { + { "mcp23s08", MCP_TYPE_S08 }, + { "mcp23s17", MCP_TYPE_S17 }, + { "mcp23s18", MCP_TYPE_S18 }, + { } +}; +MODULE_DEVICE_TABLE(spi, mcp23s08_ids); + +static const struct of_device_id mcp23s08_spi_of_match[] = { + { + .compatible = "microchip,mcp23s08", + .data = (void *) MCP_TYPE_S08, + }, + { + .compatible = "microchip,mcp23s17", + .data = (void *) MCP_TYPE_S17, + }, + { + .compatible = "microchip,mcp23s18", + .data = (void *) MCP_TYPE_S18, + }, +/* NOTE: The use of the mcp prefix is deprecated and will be removed. */ + { + .compatible = "mcp,mcp23s08", + .data = (void *) MCP_TYPE_S08, + }, + { + .compatible = "mcp,mcp23s17", + .data = (void *) MCP_TYPE_S17, + }, + { } +}; +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"); |