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Commit e789995d authored by Viresh Kumar's avatar Viresh Kumar Committed by Samuel Ortiz
Browse files

mfd: Add support for STMPE SPI interface 



Few STMPE controller can have register interface over SPI or I2C. Current
implementation only supports I2C.

This patch adds support for SPI interface for accessing STMPE's address space.

Signed-off-by: default avatarViresh Kumar <viresh.kumar@st.com>
Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent 1a6e4b74

drivers/mfd/Kconfig

+7 −1
Original line number Diff line number Diff line
@@ -258,7 +258,7 @@ config TWL6040_CORE 


config MFD_STMPE

	bool "Support STMicroelectronics STMPE"

	depends on I2C=y && GENERIC_HARDIRQS

	depends on (I2C=y || SPI_MASTER=y) && GENERIC_HARDIRQS

	select MFD_CORE

	help

	  Support for the STMPE family of I/O Expanders from
@@ -288,6 +288,12 @@ config STMPE_I2C 
	default y

	help

	  This is used to enable I2C interface of STMPE



config STMPE_SPI

	bool "STMPE SPI Inteface"

	depends on SPI_MASTER

	help

	  This is used to enable SPI interface of STMPE

endmenu



config MFD_TC3589X

drivers/mfd/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ obj-$(CONFIG_MFD_TI_SSP) += ti-ssp.o 


obj-$(CONFIG_MFD_STMPE)		+= stmpe.o

obj-$(CONFIG_STMPE_I2C)		+= stmpe-i2c.o

obj-$(CONFIG_STMPE_SPI)		+= stmpe-spi.o

obj-$(CONFIG_MFD_TC3589X)	+= tc3589x.o

obj-$(CONFIG_MFD_T7L66XB)	+= t7l66xb.o tmio_core.o

obj-$(CONFIG_MFD_TC6387XB)	+= tc6387xb.o tmio_core.o

drivers/mfd/stmpe-spi.c

0 → 100644
+148 −0
Original line number Diff line number Diff line 
/*

 * 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.kumar@st.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 __devinit

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 __devexit stmpe_spi_remove(struct spi_device *spi)

{

	struct stmpe *stmpe = dev_get_drvdata(&spi->dev);



	return stmpe_remove(stmpe);

}



static const struct spi_device_id stmpe_spi_id[] = {

	{ "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",

		.bus	= &spi_bus_type,

		.owner	= THIS_MODULE,

#ifdef CONFIG_PM

		.pm	= &stmpe_dev_pm_ops,

#endif

	},

	.probe		= stmpe_spi_probe,

	.remove		= __devexit_p(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.kumar@st.com>");

drivers/mfd/stmpe.h

+1 −0
Original line number Diff line number Diff line
@@ -120,6 +120,7 @@ int stmpe_remove(struct stmpe *stmpe); 


#define STMPE811_REG_CHIP_ID		0x00

#define STMPE811_REG_SYS_CTRL2		0x04

#define STMPE811_REG_SPI_CFG		0x08

#define STMPE811_REG_INT_CTRL		0x09

#define STMPE811_REG_INT_EN		0x0A

#define STMPE811_REG_INT_STA		0x0B