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