* [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander
@ 2007-12-10 9:39 eric miao
2007-12-12 4:29 ` [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander[ David Brownell
0 siblings, 1 reply; 6+ messages in thread
From: eric miao @ 2007-12-10 9:39 UTC (permalink / raw)
To: Linux Kernel list, linux-arm-kernel, i2c; +Cc: David Brownell
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"
Signed-off-by: eric miao <eric.miao@marvell.com>
Acked-by: Ben Gardner <bgardner@wabtec.com>
---
drivers/gpio/Kconfig | 10 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/pca9539.c | 248 +++++++++++++++++++++++++++++++++++++++++++
include/linux/i2c/pca9539.h | 18 +++
4 files changed, 277 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..6528fce 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -32,6 +32,16 @@ config GPIO_PCF857X
This driver provides an in-kernel interface to those GPIOs using
platform-neutral GPIO calls.
+config GPIO_PCA9539
+ tristate "Philips PCA9539 16-bit I/O port"
+ depends on I2C
+ help
+ If you say yes here you get support for the Philips PCA9539
+ 16-bit I/O port.
+
+ This driver can also be built as a module. If so, the module
+ will be called pca9539.
+
comment "SPI GPIO expanders:"
config GPIO_MCP23S08
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 575bb57..5f32943 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -2,3 +2,4 @@
obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o
obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o
+obj-$(CONFIG_GPIO_PCA9539) += pca9539.o
diff --git a/drivers/gpio/pca9539.c b/drivers/gpio/pca9539.c
new file mode 100644
index 0000000..0a3ae6a
--- /dev/null
+++ b/drivers/gpio/pca9539.c
@@ -0,0 +1,248 @@
+/*
+ pca9539.c - 16-bit I/O port with interrupt and reset
+
+ Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
+ Copyright (C) 2007 Marvell Internation Ltd.
+
+ 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) {
+ printk(KERN_ERR "%s: failed to read\n", __FUNCTION__);
+ 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 registers */
+ chip->reg_output = 0xffff;
+ chip->reg_direction = 0xffff;
+
+ pca9539_write_reg(chip, PCA9539_OUTPUT, chip->reg_output);
+ pca9539_write_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);
+}
+
+static void __exit pca9539_exit(void)
+{
+ i2c_del_driver(&pca9539_driver);
+}
+
+MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
+MODULE_DESCRIPTION("PCA9539 driver");
+MODULE_LICENSE("GPL");
+
+module_init(pca9539_init);
+module_exit(pca9539_exit);
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
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander[
2007-12-10 9:39 [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander eric miao
@ 2007-12-12 4:29 ` David Brownell
2007-12-14 16:08 ` Jean Delvare
2007-12-15 3:56 ` eric miao
0 siblings, 2 replies; 6+ messages in thread
From: David Brownell @ 2007-12-12 4:29 UTC (permalink / raw)
To: eric miao; +Cc: Linux Kernel list, linux-arm-kernel, i2c
[ do we need so much crossposting on these patches? ]
On Monday 10 December 2007, eric miao wrote:
> + Copyright (C) 2007 Marvell Internation Ltd.
"International"?
> +static int __devinit pca9539_probe(struct i2c_client *client)
> +{
> + ...
> + /* initialize registers */
> + chip->reg_output = 0xffff;
> + chip->reg_direction = 0xffff;
> +
> + pca9539_write_reg(chip, PCA9539_OUTPUT, chip->reg_output);
> + pca9539_write_reg(chip, PCA9539_DIRECTION, chip->reg_direction);
I thought you were going to change that code to use whatever values
were previously found in those registers? What this does is change
those values to act as if the chip just came from reset. Which isn't
the best approach when a bootloader initialized it, or if the values
were otherwise set up by something ... the previous kernel before a
kexec, this one before "rmmod pca9539", or something similar.
> +MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
But not you?
Here's a slightly cleaned up version ... address the issues above
and I'd say this one is ready to join the queue (after the other
gpiolib patches).
- Dave
============ SNIP
From: eric miao <eric.miao@marvell.com>
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)
(b) 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@marvell.com>
Acked-by: Ben Gardner <bgardner@wabtec.com>
- Alphabetized Kconfig and Makefile
- Corrected description: not "Philips", but NXP or TI
- Use dev_err() not printk
- Move module_{init,exit} next to those routines
- Did NOT change clobber of output and direction registers
---
drivers/gpio/Kconfig | 10 +
drivers/gpio/Makefile | 1
drivers/gpio/pca9539.c | 249 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/i2c/pca9539.h | 18 +++
4 files changed, 278 insertions(+)
--- a/drivers/gpio/Kconfig 2007-12-11 09:30:43.000000000 -0800
+++ b/drivers/gpio/Kconfig 2007-12-11 17:16:16.000000000 -0800
@@ -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
--- a/drivers/gpio/Makefile 2007-12-11 09:30:43.000000000 -0800
+++ b/drivers/gpio/Makefile 2007-12-11 17:15:18.000000000 -0800
@@ -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
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ b/drivers/gpio/pca9539.c 2007-12-11 19:54:57.000000000 -0800
@@ -0,0 +1,249 @@
+/*
+ pca9539.c - 16-bit I/O port with interrupt and reset
+
+ Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
+ Copyright (C) 2007 Marvell Internation Ltd.
+
+ 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, "read error %d\n", ret);
+ 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 registers */
+ chip->reg_output = 0xffff;
+ chip->reg_direction = 0xffff;
+
+ pca9539_write_reg(chip, PCA9539_OUTPUT, chip->reg_output);
+ pca9539_write_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("Ben Gardner <bgardner@wabtec.com>");
+MODULE_DESCRIPTION("PCA9539 driver");
+MODULE_LICENSE("GPL");
+
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ b/include/linux/i2c/pca9539.h 2007-12-11 09:30:44.000000000 -0800
@@ -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);
+};
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander[
2007-12-12 4:29 ` [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander[ David Brownell
@ 2007-12-14 16:08 ` Jean Delvare
2007-12-14 17:15 ` [i2c] " BGardner
2007-12-15 3:56 ` eric miao
1 sibling, 1 reply; 6+ messages in thread
From: Jean Delvare @ 2007-12-14 16:08 UTC (permalink / raw)
To: David Brownell; +Cc: eric miao, Linux Kernel list, i2c, linux-arm-kernel
Hi David,
On Tue, 11 Dec 2007 20:29:49 -0800, David Brownell wrote:
> > +static int __devinit pca9539_probe(struct i2c_client *client)
> > +{
> > + ...
> > + /* initialize registers */
> > + chip->reg_output = 0xffff;
> > + chip->reg_direction = 0xffff;
> > +
> > + pca9539_write_reg(chip, PCA9539_OUTPUT, chip->reg_output);
> > + pca9539_write_reg(chip, PCA9539_DIRECTION, chip->reg_direction);
>
> I thought you were going to change that code to use whatever values
> were previously found in those registers? What this does is change
> those values to act as if the chip just came from reset. Which isn't
> the best approach when a bootloader initialized it, or if the values
> were otherwise set up by something ... the previous kernel before a
> kexec, this one before "rmmod pca9539", or something similar.
I fully agree, preserving the initial values as much as possible is
better.
> > +MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
>
> But not you?
I'm not even sure if Ben can be said to be an author of this new
driver, as there is almost no common code between the old driver and
the new one.
> Here's a slightly cleaned up version ... address the issues above
> and I'd say this one is ready to join the queue (after the other
> gpiolib patches).
>
> - Dave
>
> ============ SNIP
> From: eric miao <eric.miao@marvell.com>
>
> 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)
> (b) 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@marvell.com>
> Acked-by: Ben Gardner <bgardner@wabtec.com>
>
> - Alphabetized Kconfig and Makefile
> - Corrected description: not "Philips", but NXP or TI
> - Use dev_err() not printk
> - Move module_{init,exit} next to those routines
> - Did NOT change clobber of output and direction registers
I think you should.
>
> ---
> drivers/gpio/Kconfig | 10 +
> drivers/gpio/Makefile | 1
> drivers/gpio/pca9539.c | 249 ++++++++++++++++++++++++++++++++++++++++++++
> include/linux/i2c/pca9539.h | 18 +++
> 4 files changed, 278 insertions(+)
>
> --- a/drivers/gpio/Kconfig 2007-12-11 09:30:43.000000000 -0800
> +++ b/drivers/gpio/Kconfig 2007-12-11 17:16:16.000000000 -0800
> @@ -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
> --- a/drivers/gpio/Makefile 2007-12-11 09:30:43.000000000 -0800
> +++ b/drivers/gpio/Makefile 2007-12-11 17:15:18.000000000 -0800
> @@ -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
> --- /dev/null 1970-01-01 00:00:00.000000000 +0000
> +++ b/drivers/gpio/pca9539.c 2007-12-11 19:54:57.000000000 -0800
> @@ -0,0 +1,249 @@
> +/*
> + pca9539.c - 16-bit I/O port with interrupt and reset
> +
> + Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
> + Copyright (C) 2007 Marvell Internation Ltd.
> +
> + 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, "read error %d\n", ret);
> + 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;
As I recall, this function doesn't need to return exactly one for
"set", so the code can be simplified a bit.
> +}
> +
> +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 registers */
> + chip->reg_output = 0xffff;
> + chip->reg_direction = 0xffff;
> +
> + pca9539_write_reg(chip, PCA9539_OUTPUT, chip->reg_output);
> + pca9539_write_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("Ben Gardner <bgardner@wabtec.com>");
> +MODULE_DESCRIPTION("PCA9539 driver");
> +MODULE_LICENSE("GPL");
> +
> --- /dev/null 1970-01-01 00:00:00.000000000 +0000
> +++ b/include/linux/i2c/pca9539.h 2007-12-11 09:30:44.000000000 -0800
> @@ -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);
> +};
>
No other objection.
--
Jean Delvare
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [i2c] [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander[
2007-12-14 16:08 ` Jean Delvare
@ 2007-12-14 17:15 ` BGardner
0 siblings, 0 replies; 6+ messages in thread
From: BGardner @ 2007-12-14 17:15 UTC (permalink / raw)
To: khali, david-b; +Cc: linux-arm-kernel, linux-kernel, i2c
Hi,
> -----Original Message-----
> > > +MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
> >
> > But not you?
>
> I'm not even sure if Ben can be said to be an author of this new
> driver, as there is almost no common code between the old driver and
> the new one.
I agree with Jean here.
Please remove me as the author.
That'll save me from getting questions about code I'm not familiar with.
=)
Thanks,
Ben
This email and any attachments are only for use by the intended recipient(s) and may contain legally privileged, confidential, proprietary or otherwise private information. Any unauthorized use, reproduction, dissemination, distribution or other disclosure of the contents of this e-mail or its attachments is strictly prohibited. If you have received this email in error, please notify the sender immediately and delete the original.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander[
2007-12-12 4:29 ` [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander[ David Brownell
2007-12-14 16:08 ` Jean Delvare
@ 2007-12-15 3:56 ` eric miao
2007-12-15 4:02 ` eric miao
1 sibling, 1 reply; 6+ messages in thread
From: eric miao @ 2007-12-15 3:56 UTC (permalink / raw)
To: David Brownell; +Cc: Linux Kernel list, linux-arm-kernel, i2c
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@marvell.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@marvell.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@wabtec.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@marvell.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
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander[
2007-12-15 3:56 ` eric miao
@ 2007-12-15 4:02 ` eric miao
0 siblings, 0 replies; 6+ messages in thread
From: eric miao @ 2007-12-15 4:02 UTC (permalink / raw)
To: David Brownell; +Cc: Linux Kernel list, linux-arm-kernel, i2c
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@gmail.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@marvell.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@marvell.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@wabtec.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@marvell.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
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2007-12-15 4:03 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-12-10 9:39 [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander eric miao
2007-12-12 4:29 ` [PATCH 2.6.24-rc4-mm 1/2] gpiolib: basic support for 16-bit PCA9539 GPIO expander[ David Brownell
2007-12-14 16:08 ` Jean Delvare
2007-12-14 17:15 ` [i2c] " BGardner
2007-12-15 3:56 ` eric miao
2007-12-15 4:02 ` eric miao
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