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gpio: mcp23s08: convert driver to DT
This converts the mcp23s08 driver to be able to be used with
device tree.
There is a "spi-present-mask" device tree property, that allows to
use multiple of this spi chips on the same chipselect.
v4:
- removed the ability to specify the pullup from device tree
- updated binding doc
v3:
- removed mcp,chips device tree property in favour of a
mcp,spi-present-mask and a flag for the pullup of every gpio
- seperated the match table. Now there is one for i2c and one for spi
- do the of reading stuff on stack of the probe function - no devm
any more
v2:
- squashed booth patches together
- fixed build warning, when CONFIG_OF is not defined
- use of_match_ptr macro for of_match_table
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Lars Poeschel
Linus Walleij
parent
a2797beadf
commit
97ddb1c88b
47
Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt
Normal file
47
Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt
Normal file
@ -0,0 +1,47 @@
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Microchip MCP2308/MCP23S08/MCP23017/MCP23S17 driver for
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8-/16-bit I/O expander with serial interface (I2C/SPI)
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Required properties:
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- compatible : Should be
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- "mcp,mcp23s08" for 8 GPIO SPI version
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- "mcp,mcp23s17" for 16 GPIO SPI version
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- "mcp,mcp23008" for 8 GPIO I2C version or
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- "mcp,mcp23017" for 16 GPIO I2C version of the chip
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- #gpio-cells : Should be two.
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- first cell is the pin number
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- second cell is used to specify flags. Flags are currently unused.
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- gpio-controller : Marks the device node as a GPIO controller.
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- reg : For an address on its bus. I2C uses this a the I2C address of the chip.
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SPI uses this to specify the chipselect line which the chip is
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connected to. The driver and the SPI variant of the chip support
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multiple chips on the same chipselect. Have a look at
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mcp,spi-present-mask below.
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Required device specific properties (only for SPI chips):
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- mcp,spi-present-mask : This is a present flag, that makes only sense for SPI
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chips - as the name suggests. Multiple SPI chips can share the same
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SPI chipselect. Set a bit in bit0-7 in this mask to 1 if there is a
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chip connected with the corresponding spi address set. For example if
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you have a chip with address 3 connected, you have to set bit3 to 1,
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which is 0x08. mcp23s08 chip variant only supports bits 0-3. It is not
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possible to mix mcp23s08 and mcp23s17 on the same chipselect. Set at
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least one bit to 1 for SPI chips.
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- spi-max-frequency = The maximum frequency this chip is able to handle
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Example I2C:
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gpiom1: gpio@20 {
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compatible = "mcp,mcp23017";
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gpio-controller;
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#gpio-cells = <2>;
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reg = <0x20>;
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};
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Example SPI:
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gpiom1: gpio@0 {
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compatible = "mcp,mcp23s17";
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gpio-controller;
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#gpio-cells = <2>;
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spi-present-mask = <0x01>;
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reg = <0>;
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spi-max-frequency = <1000000>;
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};
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@ -12,6 +12,8 @@
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#include <linux/spi/mcp23s08.h>
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#include <linux/slab.h>
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#include <asm/byteorder.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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/**
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* MCP types supported by driver
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@ -383,6 +385,10 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
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mcp->chip.direction_output = mcp23s08_direction_output;
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mcp->chip.set = mcp23s08_set;
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mcp->chip.dbg_show = mcp23s08_dbg_show;
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#ifdef CONFIG_OF
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mcp->chip.of_gpio_n_cells = 2;
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mcp->chip.of_node = dev->of_node;
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#endif
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switch (type) {
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#ifdef CONFIG_SPI_MASTER
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@ -473,6 +479,35 @@ fail:
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/*----------------------------------------------------------------------*/
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#ifdef CONFIG_OF
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#ifdef CONFIG_SPI_MASTER
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static struct of_device_id mcp23s08_spi_of_match[] = {
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{
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.compatible = "mcp,mcp23s08", .data = (void *) MCP_TYPE_S08,
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},
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{
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.compatible = "mcp,mcp23s17", .data = (void *) MCP_TYPE_S17,
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},
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{ },
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};
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MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match);
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#endif
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#if IS_ENABLED(CONFIG_I2C)
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static struct of_device_id mcp23s08_i2c_of_match[] = {
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{
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.compatible = "mcp,mcp23008", .data = (void *) MCP_TYPE_008,
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},
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{
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.compatible = "mcp,mcp23017", .data = (void *) MCP_TYPE_017,
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},
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{ },
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};
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MODULE_DEVICE_TABLE(of, mcp23s08_i2c_of_match);
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#endif
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#endif /* CONFIG_OF */
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#if IS_ENABLED(CONFIG_I2C)
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static int mcp230xx_probe(struct i2c_client *client,
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@ -480,12 +515,23 @@ static int mcp230xx_probe(struct i2c_client *client,
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{
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struct mcp23s08_platform_data *pdata;
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struct mcp23s08 *mcp;
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int status;
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int status, base, pullups;
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const struct of_device_id *match;
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pdata = client->dev.platform_data;
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if (!pdata || !gpio_is_valid(pdata->base)) {
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dev_dbg(&client->dev, "invalid or missing platform data\n");
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return -EINVAL;
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match = of_match_device(of_match_ptr(mcp23s08_i2c_of_match),
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&client->dev);
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if (match) {
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base = -1;
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pullups = 0;
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} else {
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pdata = client->dev.platform_data;
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if (!pdata || !gpio_is_valid(pdata->base)) {
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dev_dbg(&client->dev,
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"invalid or missing platform data\n");
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return -EINVAL;
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}
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base = pdata->base;
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pullups = pdata->chip[0].pullups;
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}
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mcp = kzalloc(sizeof *mcp, GFP_KERNEL);
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@ -493,8 +539,7 @@ static int mcp230xx_probe(struct i2c_client *client,
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return -ENOMEM;
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status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
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id->driver_data, pdata->base,
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pdata->chip[0].pullups);
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id->driver_data, base, pullups);
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if (status)
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goto fail;
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@ -531,6 +576,7 @@ static struct i2c_driver mcp230xx_driver = {
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.driver = {
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.name = "mcp230xx",
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.owner = THIS_MODULE,
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.of_match_table = of_match_ptr(mcp23s08_i2c_of_match),
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},
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.probe = mcp230xx_probe,
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.remove = mcp230xx_remove,
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@ -565,28 +611,55 @@ static int mcp23s08_probe(struct spi_device *spi)
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unsigned chips = 0;
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struct mcp23s08_driver_data *data;
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int status, type;
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unsigned base;
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unsigned base = -1,
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ngpio = 0,
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pullups[ARRAY_SIZE(pdata->chip)];
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const struct of_device_id *match;
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u32 spi_present_mask = 0;
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type = spi_get_device_id(spi)->driver_data;
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match = of_match_device(of_match_ptr(mcp23s08_spi_of_match), &spi->dev);
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if (match) {
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type = (int)match->data;
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status = of_property_read_u32(spi->dev.of_node,
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"mcp,spi-present-mask", &spi_present_mask);
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if (status) {
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dev_err(&spi->dev, "DT has no spi-present-mask\n");
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return -ENODEV;
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}
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if ((spi_present_mask <= 0) || (spi_present_mask >= 256)) {
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dev_err(&spi->dev, "invalid spi-present-mask\n");
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return -ENODEV;
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}
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pdata = spi->dev.platform_data;
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if (!pdata || !gpio_is_valid(pdata->base)) {
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dev_dbg(&spi->dev, "invalid or missing platform data\n");
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return -EINVAL;
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}
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for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
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if (!pdata->chip[addr].is_present)
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continue;
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chips++;
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if ((type == MCP_TYPE_S08) && (addr > 3)) {
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dev_err(&spi->dev,
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"mcp23s08 only supports address 0..3\n");
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for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++)
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pullups[addr] = 0;
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} else {
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type = spi_get_device_id(spi)->driver_data;
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pdata = spi->dev.platform_data;
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if (!pdata || !gpio_is_valid(pdata->base)) {
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dev_dbg(&spi->dev,
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"invalid or missing platform data\n");
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return -EINVAL;
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}
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for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
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if (!pdata->chip[addr].is_present)
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continue;
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chips++;
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if ((type == MCP_TYPE_S08) && (addr > 3)) {
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dev_err(&spi->dev,
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"mcp23s08 only supports address 0..3\n");
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return -EINVAL;
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}
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spi_present_mask |= 1 << addr;
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pullups[addr] = pdata->chip[addr].pullups;
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}
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if (!chips)
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return -ENODEV;
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base = pdata->base;
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}
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if (!chips)
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return -ENODEV;
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data = kzalloc(sizeof *data + chips * sizeof(struct mcp23s08),
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GFP_KERNEL);
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@ -594,21 +667,22 @@ static int mcp23s08_probe(struct spi_device *spi)
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return -ENOMEM;
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spi_set_drvdata(spi, data);
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base = pdata->base;
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for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
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if (!pdata->chip[addr].is_present)
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if (!(spi_present_mask & (1 << addr)))
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continue;
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chips--;
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data->mcp[addr] = &data->chip[chips];
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status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
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0x40 | (addr << 1), type, base,
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pdata->chip[addr].pullups);
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pullups[addr]);
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if (status < 0)
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goto fail;
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base += (type == MCP_TYPE_S17) ? 16 : 8;
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if (base != -1)
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base += (type == MCP_TYPE_S17) ? 16 : 8;
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ngpio += (type == MCP_TYPE_S17) ? 16 : 8;
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}
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data->ngpio = base - pdata->base;
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data->ngpio = ngpio;
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/* NOTE: these chips have a relatively sane IRQ framework, with
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* per-signal masking and level/edge triggering. It's not yet
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@ -668,6 +742,7 @@ static struct spi_driver mcp23s08_driver = {
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.driver = {
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.name = "mcp23s08",
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.owner = THIS_MODULE,
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.of_match_table = of_match_ptr(mcp23s08_spi_of_match),
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},
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};
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