[PATCH v3] ARM/mx35/3ds: gpio: add mc9s08dz60 gpio function
Marc Kleine-Budde
mkl at pengutronix.de
Wed Nov 9 10:46:00 EST 2011
On 11/04/2011 11:12 AM, wu guoxing wrote:
> 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.
see comments inline
Marc
>
> Signed-off-by: Wu Guoxing <b39297 at freescale.com>
> ---
> 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 | 167 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 174 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
> diff --git a/drivers/gpio/gpio-mc9s08dz60.c b/drivers/gpio/gpio-mc9s08dz60.c
> new file mode 100644
> index 0000000..c41eb16
> --- /dev/null
> +++ b/drivers/gpio/gpio-mc9s08dz60.c
> @@ -0,0 +1,167 @@
> +/*
> + * Copyright 2009-2011 Freescale Semiconductor, Inc. All Rightos Reserved.
> + *
> + * Author: Wu Guoxing <b39297 at 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)
> +{
> + return container_of(gc, struct mc9s08dz60, chip);
> +}
> +
> +
> +static void gpio_to_reg_and_bit(int offset, u8 *reg, u8 *bit)
> +{
> + *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, ®, &bit);
> + value = i2c_smbus_read_byte_data(mc9s->client, reg);
> + if (value >= 0)
> + ret = (value >> bit) & 0x1;
> +
> + return ret;
> +}
> +
> +static void mc9s08dz60_set_value(struct gpio_chip *gc, unsigned offset, int val)
> +{
> + u8 reg, bit;
> + s32 value;
> + struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);
> +
> + gpio_to_reg_and_bit(offset, ®, &bit);
> + value = i2c_smbus_read_byte_data(mc9s->client, reg);
> + if (value >= 0) {
> + if (val)
> + value |= 1 << bit;
> + else
> + value &= ~(1 << bit);
> +
> + i2c_smbus_write_byte_data(mc9s->client, reg, value);
> + }
what about propagating potential error values here?
> +}
> +
> +static int mc9s08dz60_direction_output(struct gpio_chip *gc,
> + unsigned offset, int val)
> +{
> + mc9s08dz60_set_value(gc, offset, val);
> + return 0;
dito
> +}
> +
> +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;
> +
> + ret = gpiochip_add(&mc9s->chip);
> + if (ret)
> + goto error;
> +
> + i2c_set_clientdata(client, mc9s);
Is it racy if you first add the gpio chip and then set the i2c client data?
> +
> + return 0;
> +
> +error:
> + 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;
return 0 if gpiochip_remove() fails?
> +
> +}
> +
> +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",
> + },
> + .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_AUTHOR("Freescale Semiconductor, Inc."
> + "Wu Guoxing <b39297 at freescale.com>");
> +MODULE_DESCRIPTION("mc9s08dz60 gpio function on mx35 3ds board");
> +MODULE_LICENSE("GPL v2");
--
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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