[PATCH v4] ARM/mx35/3ds: gpio: add mc9s08dz60 gpio function

[grant.likely@secretlab.ca (Grant Likely)]

On Thu, Nov 10, 2011 at 10:24:10AM +0800, y at shlinux1.ap.freescale.net wrote:
> From: wu guoxing <b39297@freescale.com>
> 
> we only use the gpio function of mc9s08dz60 mcu chip, so just
> add the gpio driver, as this mcu will never be used in other board.
> 
> Signed-off-by: Wu Guoxing <b39297@freescale.com>
> ---
> changes since v3:
> 	1. set i2c client data before gpiochip_add
> 	2. return error value in mc9s08dz60_direction_output
> v3 Changes since v1:
> 	1. add can_sleep = 1
> 	2. removed some useless return checks and local variable
> 	3. removed the static variable for i2c client.
> 	4. make init&exit function static
> 
>  drivers/gpio/Kconfig           |    6 ++
>  drivers/gpio/Makefile          |    1 +
>  drivers/gpio/gpio-mc9s08dz60.c |  177 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 184 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/gpio/gpio-mc9s08dz60.c
> 
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index d539efd..7f6beee 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -487,4 +487,10 @@ config GPIO_TPS65910
>  	help
>  	  Select this option to enable GPIO driver for the TPS65910
>  	  chip family.
> +
> +config GPIO_MC9S08DZ60
> +	bool "MX35 3DS BOARD MC9S08DZ60 GPIO functions"
> +	depends on I2C && MACH_MX35_3DS
> +	help
> +	  Select this to enable the MC9S08DZ60 GPIO driver
>  endif
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index 9588948..85b8799 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -60,3 +60,4 @@ obj-$(CONFIG_GPIO_WM831X)	+= gpio-wm831x.o
>  obj-$(CONFIG_GPIO_WM8350)	+= gpio-wm8350.o
>  obj-$(CONFIG_GPIO_WM8994)	+= gpio-wm8994.o
>  obj-$(CONFIG_GPIO_XILINX)	+= gpio-xilinx.o
> +obj-$(CONFIG_GPIO_MC9S08DZ60) += gpio-mc9s08dz60.o

This list is sorted alphabetically.  Please keep it that way.

> diff --git a/drivers/gpio/gpio-mc9s08dz60.c b/drivers/gpio/gpio-mc9s08dz60.c
> new file mode 100644
> index 0000000..0122ef8
> --- /dev/null
> +++ b/drivers/gpio/gpio-mc9s08dz60.c
> @@ -0,0 +1,177 @@
> +/*
> + * Copyright 2009-2011 Freescale Semiconductor, Inc. All Rights Reserved.
> + *
> + * Author: Wu Guoxing <b39297@freescale.com>
> + *
> + * 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 <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/i2c.h>
> +#include <linux/gpio.h>
> +
> +#define GPIO_GROUP_NUM 2
> +#define GPIO_NUM_PER_GROUP 8
> +#define GPIO_NUM (GPIO_GROUP_NUM*GPIO_NUM_PER_GROUP)
> +
> +struct mc9s08dz60 {
> +	struct i2c_client *client;
> +	struct gpio_chip chip;
> +};
> +
> +static struct mc9s08dz60 *to_mc9s08dz60(struct gpio_chip *gc)

static inline

> +{
> +	return container_of(gc, struct mc9s08dz60, chip);
> +}
> +
> +
> +static void gpio_to_reg_and_bit(int offset, u8 *reg, u8 *bit)

Protect against namespace collisions and put a mc9s... prefix on this
function.

> +{
> +	*reg = 0x20 + offset / GPIO_NUM_PER_GROUP;
> +	*bit = offset % GPIO_NUM_PER_GROUP;
> +}
> +
> +static int mc9s08dz60_get_value(struct gpio_chip *gc, unsigned offset)
> +{
> +	int ret = 0;
> +	u8 reg, bit;
> +	s32 value;
> +	struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);
> +
> +	gpio_to_reg_and_bit(offset, &reg, &bit);
> +	value = i2c_smbus_read_byte_data(mc9s->client, reg);
> +	if (value >= 0)
> +		ret = (value >> bit) & 0x1;
> +
> +	return ret;

	return (value >= 0) ? (value >> bit) & 1 : 0;

> +}
> +
> +static int _mc9s08dz60_set(struct mc9s08dz60 *mc9s, unsigned offset, int val)

Single leader underscore '_' is reserved.  Use either two underscores
'__' or none at all.

> +{
> +	u8 reg, bit;
> +	s32 value;
> +
> +	gpio_to_reg_and_bit(offset, &reg, &bit);
> +	value = i2c_smbus_read_byte_data(mc9s->client, reg);
> +	if (value >= 0) {
> +		if (val)
> +			value |= 1 << bit;
> +		else
> +			value &= ~(1 << bit);
> +
> +		return i2c_smbus_write_byte_data(mc9s->client, reg, value);
> +	} else
> +		return value;
> +
> +}
> +
> +
> +static void mc9s08dz60_set_value(struct gpio_chip *gc, unsigned offset, int val)
> +{
> +	struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);
> +
> +	_mc9s08dz60_set(mc9s, offset, val);
> +}
> +
> +static int mc9s08dz60_direction_output(struct gpio_chip *gc,
> +				       unsigned offset, int val)
> +{
> +	struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);
> +
> +	return _mc9s08dz60_set(mc9s, offset, val);
> +}
> +
> +static int mc9s08dz60_probe(struct i2c_client *client,
> +			    const struct i2c_device_id *id)
> +{
> +	int ret = 0;
> +	struct mc9s08dz60 *mc9s;
> +
> +	mc9s = kzalloc(sizeof(*mc9s), GFP_KERNEL);
> +	if (!mc9s)
> +		return -ENOMEM;
> +
> +	mc9s->chip.label = client->name;
> +	mc9s->chip.base = -1;
> +	mc9s->chip.dev = &client->dev;
> +	mc9s->chip.owner = THIS_MODULE;
> +	mc9s->chip.ngpio = GPIO_NUM;
> +	mc9s->chip.can_sleep = 1;
> +	mc9s->chip.get = mc9s08dz60_get_value;
> +	mc9s->chip.set = mc9s08dz60_set_value;
> +	mc9s->chip.direction_output = mc9s08dz60_direction_output;
> +	mc9s->client = client;
> +	i2c_set_clientdata(client, mc9s);
> +
> +	ret = gpiochip_add(&mc9s->chip);
> +	if (ret)
> +		goto error;
> +
> +	return 0;
> +
> +error:

Tip: insert one space before a label so that diff will show the
function name on context output instead of the label name.

> +	i2c_set_clientdata(client, NULL);
> +	kfree(mc9s);
> +	return ret;
> +}
> +
> +static int mc9s08dz60_remove(struct i2c_client *client)
> +{
> +	struct mc9s08dz60 *mc9s;
> +	int ret;
> +
> +	mc9s = i2c_get_clientdata(client);
> +
> +	i2c_set_clientdata(client, NULL);
> +
> +	ret = gpiochip_remove(&mc9s->chip);
> +	if (!ret)
> +		kfree(mc9s);
> +
> +	return 0;
> +
> +}
> +
> +static const struct i2c_device_id mc9s08dz60_id[] = {
> +	{"mc9s08dz60", 0},
> +	{},
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, mc9s08dz60_id);
> +
> +static struct i2c_driver mc9s08dz60_i2c_driver = {
> +	.driver = {.owner = THIS_MODULE,
> +		   .name = "mc9s08dz60",
> +		   },

Please use this indentation for static initializers:
	.driver = {
		.owner = THIS_MODULE,
		.name = "mc9s08dz60",
	},

> +	.probe = mc9s08dz60_probe,
> +	.remove = mc9s08dz60_remove,
> +	.id_table = mc9s08dz60_id,
> +};
> +
> +static int __init mc9s08dz60_init(void)
> +{
> +	return i2c_add_driver(&mc9s08dz60_i2c_driver);
> +}
> +
> +static void __exit mc9s08dz60_exit(void)
> +{
> +	i2c_del_driver(&mc9s08dz60_i2c_driver);
> +}
> +
> +module_init(mc9s08dz60_init);
> +module_exit(mc9s08dz60_exit);

module_i2c_driver() is preferred now.

> +
> +MODULE_AUTHOR("Freescale Semiconductor, Inc."
> +		"Wu Guoxing <b39297@freescale.com>");

There is no space between "...Inc." and "Wu...", which is probably not
what you want.  :-)

Otherwise looks good.  One respin and it should be ready for merging.

g.