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Message-ID: <f17812d70712142002t3ba881b0wb4ef738ca400c281@mail.gmail.com>
Date: Sat, 15 Dec 2007 12:02:54 +0800
From: "eric miao" <eric.y.miao@...il.com>
To: "David Brownell" <david-b@...bell.net>
Cc: "Linux Kernel list" <linux-kernel@...r.kernel.org>,
linux-arm-kernel <linux-arm-kernel@...ts.arm.linux.org.uk>,
i2c@...sensors.org
Subject: Re: [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander[
I'd like to create another thread in LKML for the updated version, sorry.
On Dec 15, 2007 11:56 AM, eric miao <eric.y.miao@...il.com> wrote:
> OK,
>
> Here's the updated version, which
> 1. modify the author info but still preserve Ben's credit in the source head
> 2. Alphabetic order in Kconfig/Makefile
> 3. typo fix and corrected Philips to NXP/TI
> 4. use dev_err instead of printk
> 5. move module_{init,exit} next to the routines
> 6. preserve initial output/direction register settings
>
> Also I'd like to fire another patch to obsolete drivers/i2c/chips/pca9539.c
> as everyone agreed.
>
> From 5ebe07bbbb236b99587296cbf603a965d284ceaf Mon Sep 17 00:00:00 2001
> From: eric miao <eric.miao@...vell.com>
> Date: Mon, 10 Dec 2007 17:19:12 +0800
> Subject: [PATCH] gpiolib: basic support for 16-bit PCA9539 GPIO expander
>
> 1. use 16-bit register access to simplify the logic, cache OUTPUT
> and DIRECTION registers for fast access
>
> 2. platform code is required to setup
> a) the numbering of GPIO for PCA9539 (base and number)
> c) pass "pca9539_platform_data" within "i2c_board_info"
>
> Derived from drivers/i2c/chips/pca9539.c (which has no current known
> users).
>
> Signed-off-by: eric miao <eric.miao@...vell.com>
> ---
> drivers/gpio/Kconfig | 10 ++
> drivers/gpio/Makefile | 1 +
> drivers/gpio/pca9539.c | 247 +++++++++++++++++++++++++++++++++++++++++++
> include/linux/i2c/pca9539.h | 18 +++
> 4 files changed, 276 insertions(+), 0 deletions(-)
> create mode 100644 drivers/gpio/pca9539.c
> create mode 100644 include/linux/i2c/pca9539.h
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index dd9e697..4b54f60 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -9,6 +9,16 @@ menu "GPIO Expanders"
>
> comment "I2C GPIO expanders:"
>
> +config GPIO_PCA9539
> + tristate "PCA9539 16-bit I/O port"
> + depends on I2C
> + help
> + Say yes here to support the PCA9539 16-bit I/O port. These
> + parts are made by NXP and TI.
> +
> + This driver can also be built as a module. If so, the module
> + will be called pca9539.
> +
> config GPIO_PCF857X
> tristate "PCF857x, PCA857x, and PCA967x I2C GPIO expanders"
> depends on I2C
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index 575bb57..d14fc1e 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -1,4 +1,5 @@
> # gpio support: dedicated expander chips, etc
>
> obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o
> +obj-$(CONFIG_GPIO_PCA9539) += pca9539.o
> obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o
> diff --git a/drivers/gpio/pca9539.c b/drivers/gpio/pca9539.c
> new file mode 100644
> index 0000000..955d891
> --- /dev/null
> +++ b/drivers/gpio/pca9539.c
> @@ -0,0 +1,247 @@
> +/*
> + * pca9539.c - 16-bit I/O port with interrupt and reset
> + *
> + * Copyright (C) 2005 Ben Gardner <bgardner@...tec.com>
> + * Copyright (C) 2007 Marvell International Ltd.
> + *
> + * Derived from drivers/i2c/chips/pca9539.c (which has no current known
> + * users).
> + *
> + * 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; version 2 of the License.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/i2c/pca9539.h>
> +
> +#include <asm/gpio.h>
> +
> +#define NR_PCA9539_GPIOS 16
> +
> +#define PCA9539_INPUT 0
> +#define PCA9539_OUTPUT 2
> +#define PCA9539_INVERT 4
> +#define PCA9539_DIRECTION 6
> +
> +struct pca9539_chip {
> + unsigned gpio_start;
> + uint16_t reg_output;
> + uint16_t reg_direction;
> +
> + struct i2c_client *client;
> + struct gpio_chip gpio_chip;
> +};
> +
> +static int pca9539_write_reg(struct pca9539_chip *chip, int reg, uint16_t val)
> +{
> + return i2c_smbus_write_word_data(chip->client, reg, val);
> +}
> +
> +static int pca9539_read_reg(struct pca9539_chip *chip, int reg, uint16_t *val)
> +{
> + int ret;
> +
> + ret = i2c_smbus_read_word_data(chip->client, reg);
> + if (ret < 0) {
> + dev_err(&chip->client->dev, "failed reading register\n");
>
> + return ret;
> + }
> +
> + *val = (uint16_t)ret;
> + return 0;
> +}
> +
> +static int pca9539_gpio_direction_input(struct gpio_chip *gc, unsigned off)
> +{
> + struct pca9539_chip *chip;
> + uint16_t reg_val;
> + int ret;
> +
> + chip = container_of(gc, struct pca9539_chip, gpio_chip);
> +
> + reg_val = chip->reg_direction | (1u << off);
> + ret = pca9539_write_reg(chip, PCA9539_DIRECTION, reg_val);
> + if (ret)
> + return ret;
> +
> + chip->reg_direction = reg_val;
> + return 0;
> +}
> +
> +static int pca9539_gpio_direction_output(struct gpio_chip *gc,
> + unsigned off, int val)
> +{
> + struct pca9539_chip *chip;
> + uint16_t reg_val;
> + int ret;
> +
> + chip = container_of(gc, struct pca9539_chip, gpio_chip);
> +
> + /* set output level */
> + if (val)
> + reg_val = chip->reg_output | (1u << off);
> + else
> + reg_val = chip->reg_output & ~(1u << off);
> +
> + ret = pca9539_write_reg(chip, PCA9539_OUTPUT, reg_val);
> + if (ret)
> + return ret;
> +
> + chip->reg_output = reg_val;
> +
> + /* then direction */
> + reg_val = chip->reg_direction & ~(1u << off);
> + ret = pca9539_write_reg(chip, PCA9539_DIRECTION, reg_val);
> + if (ret)
> + return ret;
> +
> + chip->reg_direction = reg_val;
> + return 0;
> +}
> +
> +static int pca9539_gpio_get_value(struct gpio_chip *gc, unsigned off)
> +{
> + struct pca9539_chip *chip;
> + uint16_t reg_val;
> + int ret;
> +
> + chip = container_of(gc, struct pca9539_chip, gpio_chip);
> +
> + ret = pca9539_read_reg(chip, PCA9539_INPUT, ®_val);
> + if (ret < 0)
> + return ret;
> +
> + return (reg_val & (1u << off)) ? 1 : 0;
> +}
> +
> +static void pca9539_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
> +{
> + struct pca9539_chip *chip;
> + uint16_t reg_val;
> + int ret;
> +
> + chip = container_of(gc, struct pca9539_chip, gpio_chip);
> +
> + if (val)
> + reg_val = chip->reg_output | (1u << off);
> + else
> + reg_val = chip->reg_output & ~(1u << off);
> +
> + ret = pca9539_write_reg(chip, PCA9539_OUTPUT, reg_val);
> + if (ret)
> + return;
> +
> + chip->reg_output = reg_val;
> +}
> +
> +static int pca9539_init_gpio(struct pca9539_chip *chip)
> +{
> + struct gpio_chip *gc;
> +
> + gc = &chip->gpio_chip;
> +
> + gc->direction_input = pca9539_gpio_direction_input;
> + gc->direction_output = pca9539_gpio_direction_output;
> + gc->get = pca9539_gpio_get_value;
> + gc->set = pca9539_gpio_set_value;
> +
> + gc->base = chip->gpio_start;
> + gc->ngpio = NR_PCA9539_GPIOS;
> + gc->label = "pca9539";
> +
> + return gpiochip_add(gc);
> +}
> +
> +static int __devinit pca9539_probe(struct i2c_client *client)
> +{
> + struct pca9539_platform_data *pdata;
> + struct pca9539_chip *chip;
> + int ret;
> +
> + pdata = client->dev.platform_data;
> + if (pdata == NULL)
> + return -ENODEV;
> +
> + chip = kzalloc(sizeof(struct pca9539_chip), GFP_KERNEL);
> + if (chip == NULL)
> + return -ENOMEM;
> +
> + chip->client = client;
> +
> + chip->gpio_start = pdata->gpio_base;
> +
> + /* initialize cached registers from their original values */
> + pca9539_read_reg(chip, PCA9539_OUTPUT, &chip->reg_output);
> + pca9539_read_reg(chip, PCA9539_DIRECTION, &chip->reg_direction);
>
> +
> + /* set platform specific polarity inversion */
> + pca9539_write_reg(chip, PCA9539_INVERT, pdata->invert);
> +
> + ret = pca9539_init_gpio(chip);
> + if (ret)
> + goto out_failed;
> +
> + if (pdata->setup) {
> + ret = pdata->setup(client, chip->gpio_chip.base,
> + chip->gpio_chip.ngpio, pdata->context);
> + if (ret < 0)
> + dev_dbg(&client->dev, "setup failed, %d\n", ret);
> + }
> +
> + i2c_set_clientdata(client, chip);
> + return 0;
> +
> +out_failed:
> + kfree(chip);
> + return ret;
> +}
> +
> +static int pca9539_remove(struct i2c_client *client)
> +{
> + struct pca9539_platform_data *pdata = client->dev.platform_data;
> + struct pca9539_chip *chip = i2c_get_clientdata(client);
> + int ret = 0;
> +
> + if (pdata->teardown) {
> + ret = pdata->teardown(client, chip->gpio_chip.base,
> + chip->gpio_chip.ngpio, pdata->context);
> + if (ret < 0)
> + dev_dbg(&client->dev, "teardown failed, %d\n", ret);
> + }
> +
> + ret = gpiochip_remove(&chip->gpio_chip);
> + if (ret) {
> + dev_err(&client->dev, "failed remove gpio_chip\n");
> + return ret;
> + }
> +
> + kfree(chip);
> + return 0;
> +}
> +
> +static struct i2c_driver pca9539_driver = {
> + .driver = {
> + .name = "pca9539",
> + },
> + .probe = pca9539_probe,
> + .remove = pca9539_remove,
> +};
> +
> +static int __init pca9539_init(void)
> +{
> + return i2c_add_driver(&pca9539_driver);
> +}
> +module_init(pca9539_init);
> +
> +static void __exit pca9539_exit(void)
> +{
> + i2c_del_driver(&pca9539_driver);
> +}
> +module_exit(pca9539_exit);
> +
> +MODULE_AUTHOR("eric miao <eric.miao@...vell.com>");
> +MODULE_DESCRIPTION("GPIO expander driver for PCA9539");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/i2c/pca9539.h b/include/linux/i2c/pca9539.h
> new file mode 100644
> index 0000000..611d84a
> --- /dev/null
> +++ b/include/linux/i2c/pca9539.h
> @@ -0,0 +1,18 @@
> +/* platform data for the PCA9539 16-bit I/O expander driver */
> +
> +struct pca9539_platform_data {
> + /* number of the first GPIO */
> + unsigned gpio_base;
> +
> + /* initial polarity inversion setting */
> + uint16_t invert;
> +
> + void *context; /* param to setup/teardown */
> +
> + int (*setup)(struct i2c_client *client,
> + unsigned gpio, unsigned ngpio,
> + void *context);
> + int (*teardown)(struct i2c_client *client,
> + unsigned gpio, unsigned ngpio,
> + void *context);
> +};
> --
> 1.5.2.5.GIT
>
> --
> Cheers
> - eric
>
--
Cheers
- eric
--
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