drivers/pinctrl/pinctrl-mcp23s08_spi.c - linux - Git at Google

 // 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,
 				    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_DESCRIPTION("MCP23S08 SPI GPIO driver");
 MODULE_LICENSE("GPL");
	// 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,
	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_DESCRIPTION("MCP23S08 SPI GPIO driver");
	MODULE_LICENSE("GPL");