[PATCH v2 1/2] mfd: add stmpe-i2c driver

Marc Kleine-Budde mkl at pengutronix.de
Tue Sep 4 04:18:27 EDT 2012


On 09/03/2012 01:03 PM, Steffen Trumtrar wrote:
> The stmpe mfds can be connected via i2c and spi. This driver provides the basic
> infrastructure for the i2c kind. It can be added as a normal i2c-device in the
> board code. To enable functions a platform_data struct has to be provided, that
> describes what parts of the chip are to be used.
> 
> Signed-off-by: Steffen Trumtrar <s.trumtrar at pengutronix.de>
> ---
>  drivers/mfd/Kconfig     |    4 ++
>  drivers/mfd/Makefile    |    1 +
>  drivers/mfd/stmpe-i2c.c |  166 +++++++++++++++++++++++++++++++++++++++++++++++
>  include/mfd/stmpe-i2c.h |   56 ++++++++++++++++
>  4 files changed, 227 insertions(+)
>  create mode 100644 drivers/mfd/stmpe-i2c.c
>  create mode 100644 include/mfd/stmpe-i2c.h
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index af67935..20eef86 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -33,4 +33,8 @@ config I2C_TWL6030
>  	select I2C_TWLCORE
>  	bool "TWL6030 driver"
>  
> +config I2C_STMPE
> +	depends on I2C
> +	bool "STMPE-i2c driver"
> +
>  endmenu
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index e11223b..792ae2d 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -6,3 +6,4 @@ obj-$(CONFIG_I2C_LP3972) += lp3972.o
>  obj-$(CONFIG_I2C_TWLCORE) += twl-core.o
>  obj-$(CONFIG_I2C_TWL4030) += twl4030.o
>  obj-$(CONFIG_I2C_TWL6030) += twl6030.o
> +obj-$(CONFIG_I2C_STMPE) += stmpe-i2c.o
> diff --git a/drivers/mfd/stmpe-i2c.c b/drivers/mfd/stmpe-i2c.c
> new file mode 100644
> index 0000000..a0cfa75
> --- /dev/null
> +++ b/drivers/mfd/stmpe-i2c.c
> @@ -0,0 +1,166 @@
> +/*
> + * Copyright (C) 2012 Pengutronix
> + * Steffen Trumtrar <s.trumtrar at pengutronix.de>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + */
> +
> +#include <common.h>
> +#include <init.h>
> +#include <driver.h>
> +#include <xfuncs.h>
> +#include <errno.h>
> +
> +#include <i2c/i2c.h>
> +#include <mfd/stmpe-i2c.h>
> +
> +#define DRIVERNAME		"stmpe-i2c"
> +
> +#define to_stmpe(a)		container_of(a, struct stmpe, cdev)
> +
> +static struct stmpe *stmpe_dev;
> +
> +struct stmpe *stmpe_get(void)
> +{
> +	if (!stmpe_dev)
> +		return NULL;

nitpick, you can remove the above return :)
> +
> +	return stmpe_dev;
> +}
> +EXPORT_SYMBOL(stmpe_get);
> +
> +int stmpe_reg_read(struct stmpe *stmpe, u32 reg, u8 *val)
> +{
> +	int ret;
> +
> +	ret = i2c_read_reg(stmpe->client, reg, val, 1);
> +
> +	return ret == 1 ? 0 : ret;
> +}
> +EXPORT_SYMBOL(stmpe_reg_read)
> +
> +int stmpe_reg_write(struct stmpe *stmpe, u32 reg, u8 val)
> +{
> +	int ret;
> +
> +	ret = i2c_write_reg(stmpe->client, reg, &val, 1);
> +
> +	return ret == 1 ? 0 : ret;
> +}
> +EXPORT_SYMBOL(stmpe_reg_write)
> +
> +int stmpe_set_bits(struct stmpe *stmpe, u32 reg, u8 mask, u8 val)
> +{
> +	u8 tmp;
> +	int err;
> +
> +	err = stmpe_reg_read(stmpe, reg, &tmp);
> +	tmp = (tmp & ~mask) | val;
> +
> +	if (!err)
> +		err = stmpe_reg_write(stmpe, reg, tmp);
> +
> +	return err;
> +}
> +EXPORT_SYMBOL(stmpe_set_bits);
> +
> +static ssize_t stmpe_read(struct cdev *cdev, void *_buf, size_t count, loff_t offset, ulong flags)
> +{
> +	struct stmpe *stmpe = to_stmpe(cdev);
> +	u8 *buf = _buf;
> +	size_t i = count;
> +	int err;
> +
> +	while (i) {
> +		err = stmpe_reg_read(stmpe, offset, buf);
> +		if (err)
> +			return (ssize_t)err;
> +		buf++;
> +		i--;
> +		offset++;
> +	}
> +
> +	return count;
> +}
> +
> +static ssize_t stmpe_write(struct cdev *cdev, const void *_buf, size_t count, loff_t offset, ulong flags)
> +{
> +	struct stmpe *stmpe = to_stmpe(cdev);
> +	const u8 *buf = _buf;
> +	size_t i = count;
> +	int err;
> +
> +	while (i) {
> +		err = stmpe_reg_write(stmpe, offset, *buf);
> +		if (err)
> +			return (ssize_t)err;
> +		buf++;
> +		i--;
> +		offset++;
> +	}
> +
> +	return count;
> +}
> +
> +static struct file_operations stmpe_fops = {
> +	.lseek	= dev_lseek_default,
> +	.read	= stmpe_read,
> +	.write	= stmpe_write,
> +};
> +
> +static struct stmpe_client_info i2c_ci = {
> +	.read_reg = stmpe_reg_read,
> +	.write_reg = stmpe_reg_write,
> +};
> +
> +static int stmpe_probe(struct device_d *dev)
> +{
> +	struct stmpe_platform_data *pdata = dev->platform_data;
> +
> +	if (!pdata) {
> +		dev_dbg(dev, "no platform data\n");
> +		return -ENODEV;
> +	}
> +
> +	if (stmpe_dev)
> +		return -EBUSY;
> +
> +	stmpe_dev = xzalloc(sizeof(struct stmpe));
> +	stmpe_dev->cdev.name = DRIVERNAME;
> +	stmpe_dev->client = to_i2c_client(dev);
> +	stmpe_dev->cdev.size = 191;		/* 191 known registers */
> +	stmpe_dev->cdev.dev = dev;
> +	stmpe_dev->cdev.ops = &stmpe_fops;
> +	stmpe_dev->pdata = pdata;
> +	dev->priv = stmpe_dev;
> +	i2c_ci.stmpe = stmpe_dev;
> +
> +	if (pdata->blocks &= STMPE_BLOCK_GPIO)
> +		add_generic_device("stmpe-gpio", 0, NULL, (void __iomem *)pdata->base, 0x10, IORESOURCE_MEM, &i2c_ci);
                                                          ^^^^^^^^^^^^^^

it's already void __iomem *, isn't it?

> +
> +	devfs_create(&stmpe_dev->cdev);
> +
> +	return 0;
> +}
> +
> +static struct driver_d stmpe_driver = {
> +	.name  = DRIVERNAME,
> +	.probe = stmpe_probe,
> +};
> +
> +static int stmpe_init(void)
> +{
> +        register_driver(&stmpe_driver);
> +        return 0;
> +}
> +
> +device_initcall(stmpe_init);
> diff --git a/include/mfd/stmpe-i2c.h b/include/mfd/stmpe-i2c.h
> new file mode 100644
> index 0000000..c36aed9
> --- /dev/null
> +++ b/include/mfd/stmpe-i2c.h
> @@ -0,0 +1,56 @@
> +/*
> + * Copyright (C) 2012 Pengutronix
> + * Steffen Trumtrar <s.trumtrar at pengutronix.de>
> + *
> + * This file is released under the GPLv2
> + *
> + */
> +
> +#ifndef __ASM_ARCH_STMPE_H
> +#define __ASM_ARCH_STMPE_H
> +
> +enum stmpe_revision {
> +	STMPE610,
> +	STMPE801,
> +	STMPE811,
> +	STMPE1601,
> +	STMPE2401,
> +	STMPE2403,
> +	STMPE_NBR_PARTS
> +};
> +
> +enum stmpe_blocks {
> +	STMPE_BLOCK_GPIO	= 1 << 0,
> +	STMPE_BLOCK_KEYPAD      = 1 << 1,
> +	STMPE_BLOCK_TOUCHSCREEN = 1 << 2,
> +	STMPE_BLOCK_ADC         = 1 << 3,
> +	STMPE_BLOCK_PWM         = 1 << 4,
> +	STMPE_BLOCK_ROTATOR     = 1 << 5,
> +};
> +
> +struct stmpe_platform_data {
> +	enum	stmpe_revision	revision;
> +	enum	stmpe_blocks	blocks;
> +	void	__iomem		*base;
> +	int			gpio_base;
> +};
> +
> +struct stmpe {
> +	struct cdev		cdev;
> +	struct i2c_client	*client;
> +	struct stmpe_platform_data *pdata;
> +};
> +
> +struct stmpe_client_info {
> +	struct stmpe *stmpe;
> +	int (*read_reg)(struct stmpe *stmpe, u32 reg, u8 *val);
> +	int (*write_reg)(struct stmpe *stmpe, u32 reg, u8 val);
> +};
> +
> +extern struct stmpe *stmpe_get(void);
> +
> +extern int stmpe_reg_read(struct stmpe *priv, u32 reg, u8 *val);
> +extern int stmpe_reg_write(struct stmpe *priv, u32 reg, u8 val);
> +extern int stmpe_set_bits(struct stmpe *priv, u32 reg, u8 mask, u8 val);
> +
> +#endif /* __ASM_ARCH_STMPE_H */
> 

Marc


-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |

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