diff options
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt | 47 | ||||
| -rw-r--r-- | drivers/gpio/gpio-mcp23s08.c | 137 |
2 files changed, 153 insertions, 31 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt new file mode 100644 index 000000000000..629d0ef17308 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt @@ -0,0 +1,47 @@ +Microchip MCP2308/MCP23S08/MCP23017/MCP23S17 driver for +8-/16-bit I/O expander with serial interface (I2C/SPI) + +Required properties: +- compatible : Should be + - "mcp,mcp23s08" for 8 GPIO SPI version + - "mcp,mcp23s17" for 16 GPIO SPI version + - "mcp,mcp23008" for 8 GPIO I2C version or + - "mcp,mcp23017" for 16 GPIO I2C version of the chip +- #gpio-cells : Should be two. + - first cell is the pin number + - second cell is used to specify flags. Flags are currently unused. +- gpio-controller : Marks the device node as a GPIO controller. +- reg : For an address on its bus. I2C uses this a the I2C address of the chip. + SPI uses this to specify the chipselect line which the chip is + connected to. The driver and the SPI variant of the chip support + multiple chips on the same chipselect. Have a look at + mcp,spi-present-mask below. + +Required device specific properties (only for SPI chips): +- mcp,spi-present-mask : This is a present flag, that makes only sense for SPI + chips - as the name suggests. Multiple SPI chips can share the same + SPI chipselect. Set a bit in bit0-7 in this mask to 1 if there is a + chip connected with the corresponding spi address set. For example if + you have a chip with address 3 connected, you have to set bit3 to 1, + which is 0x08. mcp23s08 chip variant only supports bits 0-3. It is not + possible to mix mcp23s08 and mcp23s17 on the same chipselect. Set at + least one bit to 1 for SPI chips. +- spi-max-frequency = The maximum frequency this chip is able to handle + +Example I2C: +gpiom1: gpio@20 { + compatible = "mcp,mcp23017"; + gpio-controller; + #gpio-cells = <2>; + reg = <0x20>; +}; + +Example SPI: +gpiom1: gpio@0 { + compatible = "mcp,mcp23s17"; + gpio-controller; + #gpio-cells = <2>; + spi-present-mask = <0x01>; + reg = <0>; + spi-max-frequency = <1000000>; +}; diff --git a/drivers/gpio/gpio-mcp23s08.c b/drivers/gpio/gpio-mcp23s08.c index 3cea0ea79e80..6a4470b84488 100644 --- a/drivers/gpio/gpio-mcp23s08.c +++ b/drivers/gpio/gpio-mcp23s08.c @@ -12,6 +12,8 @@ #include <linux/spi/mcp23s08.h> #include <linux/slab.h> #include <asm/byteorder.h> +#include <linux/of.h> +#include <linux/of_device.h> /** * MCP types supported by driver @@ -383,6 +385,10 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev, mcp->chip.direction_output = mcp23s08_direction_output; mcp->chip.set = mcp23s08_set; mcp->chip.dbg_show = mcp23s08_dbg_show; +#ifdef CONFIG_OF + mcp->chip.of_gpio_n_cells = 2; + mcp->chip.of_node = dev->of_node; +#endif switch (type) { #ifdef CONFIG_SPI_MASTER @@ -473,6 +479,35 @@ fail: /*----------------------------------------------------------------------*/ +#ifdef CONFIG_OF +#ifdef CONFIG_SPI_MASTER +static struct of_device_id mcp23s08_spi_of_match[] = { + { + .compatible = "mcp,mcp23s08", .data = (void *) MCP_TYPE_S08, + }, + { + .compatible = "mcp,mcp23s17", .data = (void *) MCP_TYPE_S17, + }, + { }, +}; +MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match); +#endif + +#if IS_ENABLED(CONFIG_I2C) +static struct of_device_id mcp23s08_i2c_of_match[] = { + { + .compatible = "mcp,mcp23008", .data = (void *) MCP_TYPE_008, + }, + { + .compatible = "mcp,mcp23017", .data = (void *) MCP_TYPE_017, + }, + { }, +}; +MODULE_DEVICE_TABLE(of, mcp23s08_i2c_of_match); +#endif +#endif /* CONFIG_OF */ + + #if IS_ENABLED(CONFIG_I2C) static int mcp230xx_probe(struct i2c_client *client, @@ -480,12 +515,23 @@ static int mcp230xx_probe(struct i2c_client *client, { struct mcp23s08_platform_data *pdata; struct mcp23s08 *mcp; - int status; - - pdata = client->dev.platform_data; - if (!pdata || !gpio_is_valid(pdata->base)) { - dev_dbg(&client->dev, "invalid or missing platform data\n"); - return -EINVAL; + int status, base, pullups; + const struct of_device_id *match; + + match = of_match_device(of_match_ptr(mcp23s08_i2c_of_match), + &client->dev); + if (match) { + base = -1; + pullups = 0; + } else { + pdata = client->dev.platform_data; + if (!pdata || !gpio_is_valid(pdata->base)) { + dev_dbg(&client->dev, + "invalid or missing platform data\n"); + return -EINVAL; + } + base = pdata->base; + pullups = pdata->chip[0].pullups; } mcp = kzalloc(sizeof *mcp, GFP_KERNEL); @@ -493,8 +539,7 @@ static int mcp230xx_probe(struct i2c_client *client, return -ENOMEM; status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr, - id->driver_data, pdata->base, - pdata->chip[0].pullups); + id->driver_data, base, pullups); if (status) goto fail; @@ -531,6 +576,7 @@ static struct i2c_driver mcp230xx_driver = { .driver = { .name = "mcp230xx", .owner = THIS_MODULE, + .of_match_table = of_match_ptr(mcp23s08_i2c_of_match), }, .probe = mcp230xx_probe, .remove = mcp230xx_remove, @@ -565,28 +611,55 @@ static int mcp23s08_probe(struct spi_device *spi) unsigned chips = 0; struct mcp23s08_driver_data *data; int status, type; - unsigned base; - - type = spi_get_device_id(spi)->driver_data; - - pdata = spi->dev.platform_data; - if (!pdata || !gpio_is_valid(pdata->base)) { - dev_dbg(&spi->dev, "invalid or missing platform data\n"); - return -EINVAL; - } + unsigned base = -1, + ngpio = 0, + pullups[ARRAY_SIZE(pdata->chip)]; + const struct of_device_id *match; + u32 spi_present_mask = 0; + + match = of_match_device(of_match_ptr(mcp23s08_spi_of_match), &spi->dev); + if (match) { + type = (int)match->data; + status = of_property_read_u32(spi->dev.of_node, + "mcp,spi-present-mask", &spi_present_mask); + if (status) { + dev_err(&spi->dev, "DT has no spi-present-mask\n"); + return -ENODEV; + } + if ((spi_present_mask <= 0) || (spi_present_mask >= 256)) { + dev_err(&spi->dev, "invalid spi-present-mask\n"); + return -ENODEV; + } - for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) { - if (!pdata->chip[addr].is_present) - continue; - chips++; - if ((type == MCP_TYPE_S08) && (addr > 3)) { - dev_err(&spi->dev, - "mcp23s08 only supports address 0..3\n"); + for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) + pullups[addr] = 0; + } else { + type = spi_get_device_id(spi)->driver_data; + pdata = spi->dev.platform_data; + if (!pdata || !gpio_is_valid(pdata->base)) { + dev_dbg(&spi->dev, + "invalid or missing platform data\n"); return -EINVAL; } + + for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) { + if (!pdata->chip[addr].is_present) + continue; + chips++; + if ((type == MCP_TYPE_S08) && (addr > 3)) { + dev_err(&spi->dev, + "mcp23s08 only supports address 0..3\n"); + return -EINVAL; + } + spi_present_mask |= 1 << addr; + pullups[addr] = pdata->chip[addr].pullups; + } + + if (!chips) + return -ENODEV; + + base = pdata->base; } - if (!chips) - return -ENODEV; data = kzalloc(sizeof *data + chips * sizeof(struct mcp23s08), GFP_KERNEL); @@ -594,21 +667,22 @@ static int mcp23s08_probe(struct spi_device *spi) return -ENOMEM; spi_set_drvdata(spi, data); - base = pdata->base; for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) { - if (!pdata->chip[addr].is_present) + if (!(spi_present_mask & (1 << addr))) continue; chips--; data->mcp[addr] = &data->chip[chips]; status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi, 0x40 | (addr << 1), type, base, - pdata->chip[addr].pullups); + pullups[addr]); if (status < 0) goto fail; - base += (type == MCP_TYPE_S17) ? 16 : 8; + if (base != -1) + base += (type == MCP_TYPE_S17) ? 16 : 8; + ngpio += (type == MCP_TYPE_S17) ? 16 : 8; } - data->ngpio = base - pdata->base; + data->ngpio = ngpio; /* NOTE: these chips have a relatively sane IRQ framework, with * per-signal masking and level/edge triggering. It's not yet @@ -668,6 +742,7 @@ static struct spi_driver mcp23s08_driver = { .driver = { .name = "mcp23s08", .owner = THIS_MODULE, + .of_match_table = of_match_ptr(mcp23s08_spi_of_match), }, }; |