diff options
Diffstat (limited to 'drivers/mfd/stmpe-spi.c')
| -rw-r--r-- | drivers/mfd/stmpe-spi.c | 149 | 
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/mfd/stmpe-spi.c b/drivers/mfd/stmpe-spi.c new file mode 100644 index 00000000000..a81badbaa91 --- /dev/null +++ b/drivers/mfd/stmpe-spi.c @@ -0,0 +1,149 @@ +/* + * ST Microelectronics MFD: stmpe's spi client specific driver + * + * Copyright (C) ST Microelectronics SA 2011 + * + * License Terms: GNU General Public License, version 2 + * Author: Viresh Kumar <viresh.linux@gmail.com> for ST Microelectronics + */ + +#include <linux/spi/spi.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include "stmpe.h" + +#define READ_CMD	(1 << 7) + +static int spi_reg_read(struct stmpe *stmpe, u8 reg) +{ +	struct spi_device *spi = stmpe->client; +	int status = spi_w8r16(spi, reg | READ_CMD); + +	return (status < 0) ? status : status >> 8; +} + +static int spi_reg_write(struct stmpe *stmpe, u8 reg, u8 val) +{ +	struct spi_device *spi = stmpe->client; +	u16 cmd = (val << 8) | reg; + +	return spi_write(spi, (const u8 *)&cmd, 2); +} + +static int spi_block_read(struct stmpe *stmpe, u8 reg, u8 length, u8 *values) +{ +	int ret, i; + +	for (i = 0; i < length; i++) { +		ret = spi_reg_read(stmpe, reg + i); +		if (ret < 0) +			return ret; +		*(values + i) = ret; +	} + +	return 0; +} + +static int spi_block_write(struct stmpe *stmpe, u8 reg, u8 length, +		const u8 *values) +{ +	int ret = 0, i; + +	for (i = length; i > 0; i--, reg++) { +		ret = spi_reg_write(stmpe, reg, *(values + i - 1)); +		if (ret < 0) +			return ret; +	} + +	return ret; +} + +static void spi_init(struct stmpe *stmpe) +{ +	struct spi_device *spi = stmpe->client; + +	spi->bits_per_word = 8; + +	/* This register is only present for stmpe811 */ +	if (stmpe->variant->id_val == 0x0811) +		spi_reg_write(stmpe, STMPE811_REG_SPI_CFG, spi->mode); + +	if (spi_setup(spi) < 0) +		dev_dbg(&spi->dev, "spi_setup failed\n"); +} + +static struct stmpe_client_info spi_ci = { +	.read_byte = spi_reg_read, +	.write_byte = spi_reg_write, +	.read_block = spi_block_read, +	.write_block = spi_block_write, +	.init = spi_init, +}; + +static int +stmpe_spi_probe(struct spi_device *spi) +{ +	const struct spi_device_id *id = spi_get_device_id(spi); + +	/* don't exceed max specified rate - 1MHz - Limitation of STMPE */ +	if (spi->max_speed_hz > 1000000) { +		dev_dbg(&spi->dev, "f(sample) %d KHz?\n", +				(spi->max_speed_hz/1000)); +		return -EINVAL; +	} + +	spi_ci.irq = spi->irq; +	spi_ci.client = spi; +	spi_ci.dev = &spi->dev; + +	return stmpe_probe(&spi_ci, id->driver_data); +} + +static int stmpe_spi_remove(struct spi_device *spi) +{ +	struct stmpe *stmpe = spi_get_drvdata(spi); + +	return stmpe_remove(stmpe); +} + +static const struct spi_device_id stmpe_spi_id[] = { +	{ "stmpe610", STMPE610 }, +	{ "stmpe801", STMPE801 }, +	{ "stmpe811", STMPE811 }, +	{ "stmpe1601", STMPE1601 }, +	{ "stmpe2401", STMPE2401 }, +	{ "stmpe2403", STMPE2403 }, +	{ } +}; +MODULE_DEVICE_TABLE(spi, stmpe_id); + +static struct spi_driver stmpe_spi_driver = { +	.driver = { +		.name	= "stmpe-spi", +		.owner	= THIS_MODULE, +#ifdef CONFIG_PM +		.pm	= &stmpe_dev_pm_ops, +#endif +	}, +	.probe		= stmpe_spi_probe, +	.remove		= stmpe_spi_remove, +	.id_table	= stmpe_spi_id, +}; + +static int __init stmpe_init(void) +{ +	return spi_register_driver(&stmpe_spi_driver); +} +subsys_initcall(stmpe_init); + +static void __exit stmpe_exit(void) +{ +	spi_unregister_driver(&stmpe_spi_driver); +} +module_exit(stmpe_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("STMPE MFD SPI Interface Driver"); +MODULE_AUTHOR("Viresh Kumar <viresh.linux@gmail.com>");  | 
