+++ /dev/null
-/*
- * drivers/i2c/busses/i2c-ixp4xx.c
- *
- * Intel's IXP4xx XScale NPU chipsets (IXP420, 421, 422, 425) do not have
- * an on board I2C controller but provide 16 GPIO pins that are often
- * used to create an I2C bus. This driver provides an i2c_adapter
- * interface that plugs in under algo_bit and drives the GPIO pins
- * as instructed by the alogorithm driver.
- *
- * Author: Deepak Saxena <dsaxena@plexity.net>
- *
- * Copyright (c) 2003-2004 MontaVista Software Inc.
- *
- * This file is licensed under the terms of the GNU General Public
- * License version 2. This program is licensed "as is" without any
- * warranty of any kind, whether express or implied.
- *
- * NOTE: Since different platforms will use different GPIO pins for
- * I2C, this driver uses an IXP4xx-specific platform_data
- * pointer to pass the GPIO numbers to the driver. This
- * allows us to support all the different IXP4xx platforms
- * w/o having to put #ifdefs in this driver.
- *
- * See arch/arm/mach-ixp4xx/ixdp425.c for an example of building a
- * device list and filling in the ixp4xx_i2c_pins data structure
- * that is passed as the platform_data to this driver.
- */
-
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/platform_device.h>
-#include <linux/module.h>
-#include <linux/i2c.h>
-#include <linux/i2c-algo-bit.h>
-
-#include <asm/hardware.h> /* Pick up IXP4xx-specific bits */
-
-static inline int ixp4xx_scl_pin(void *data)
-{
- return ((struct ixp4xx_i2c_pins*)data)->scl_pin;
-}
-
-static inline int ixp4xx_sda_pin(void *data)
-{
- return ((struct ixp4xx_i2c_pins*)data)->sda_pin;
-}
-
-static void ixp4xx_bit_setscl(void *data, int val)
-{
- gpio_line_set(ixp4xx_scl_pin(data), 0);
- gpio_line_config(ixp4xx_scl_pin(data),
- val ? IXP4XX_GPIO_IN : IXP4XX_GPIO_OUT );
-}
-
-static void ixp4xx_bit_setsda(void *data, int val)
-{
- gpio_line_set(ixp4xx_sda_pin(data), 0);
- gpio_line_config(ixp4xx_sda_pin(data),
- val ? IXP4XX_GPIO_IN : IXP4XX_GPIO_OUT );
-}
-
-static int ixp4xx_bit_getscl(void *data)
-{
- int scl;
-
- gpio_line_config(ixp4xx_scl_pin(data), IXP4XX_GPIO_IN );
- gpio_line_get(ixp4xx_scl_pin(data), &scl);
-
- return scl;
-}
-
-static int ixp4xx_bit_getsda(void *data)
-{
- int sda;
-
- gpio_line_config(ixp4xx_sda_pin(data), IXP4XX_GPIO_IN );
- gpio_line_get(ixp4xx_sda_pin(data), &sda);
-
- return sda;
-}
-
-struct ixp4xx_i2c_data {
- struct ixp4xx_i2c_pins *gpio_pins;
- struct i2c_adapter adapter;
- struct i2c_algo_bit_data algo_data;
-};
-
-static int ixp4xx_i2c_remove(struct platform_device *plat_dev)
-{
- struct ixp4xx_i2c_data *drv_data = platform_get_drvdata(plat_dev);
-
- platform_set_drvdata(plat_dev, NULL);
-
- i2c_del_adapter(&drv_data->adapter);
-
- kfree(drv_data);
-
- return 0;
-}
-
-static int ixp4xx_i2c_probe(struct platform_device *plat_dev)
-{
- int err;
- struct ixp4xx_i2c_pins *gpio = plat_dev->dev.platform_data;
- struct ixp4xx_i2c_data *drv_data =
- kzalloc(sizeof(struct ixp4xx_i2c_data), GFP_KERNEL);
-
- if(!drv_data)
- return -ENOMEM;
-
- drv_data->gpio_pins = gpio;
-
- /*
- * We could make a lot of these structures static, but
- * certain platforms may have multiple GPIO-based I2C
- * buses for various device domains, so we need per-device
- * algo_data->data.
- */
- drv_data->algo_data.data = gpio;
- drv_data->algo_data.setsda = ixp4xx_bit_setsda;
- drv_data->algo_data.setscl = ixp4xx_bit_setscl;
- drv_data->algo_data.getsda = ixp4xx_bit_getsda;
- drv_data->algo_data.getscl = ixp4xx_bit_getscl;
- drv_data->algo_data.udelay = 10;
- drv_data->algo_data.timeout = 100;
-
- drv_data->adapter.id = I2C_HW_B_IXP4XX;
- drv_data->adapter.class = I2C_CLASS_HWMON;
- strlcpy(drv_data->adapter.name, plat_dev->dev.driver->name,
- sizeof(drv_data->adapter.name));
- drv_data->adapter.algo_data = &drv_data->algo_data;
-
- drv_data->adapter.dev.parent = &plat_dev->dev;
-
- gpio_line_config(gpio->scl_pin, IXP4XX_GPIO_IN);
- gpio_line_config(gpio->sda_pin, IXP4XX_GPIO_IN);
- gpio_line_set(gpio->scl_pin, 0);
- gpio_line_set(gpio->sda_pin, 0);
-
- err = i2c_bit_add_bus(&drv_data->adapter);
- if (err) {
- printk(KERN_ERR "ERROR: Could not install %s\n", plat_dev->dev.bus_id);
-
- kfree(drv_data);
- return err;
- }
-
- platform_set_drvdata(plat_dev, drv_data);
-
- return 0;
-}
-
-static struct platform_driver ixp4xx_i2c_driver = {
- .probe = ixp4xx_i2c_probe,
- .remove = ixp4xx_i2c_remove,
- .driver = {
- .name = "IXP4XX-I2C",
- .owner = THIS_MODULE,
- },
-};
-
-static int __init ixp4xx_i2c_init(void)
-{
- return platform_driver_register(&ixp4xx_i2c_driver);
-}
-
-static void __exit ixp4xx_i2c_exit(void)
-{
- platform_driver_unregister(&ixp4xx_i2c_driver);
-}
-
-module_init(ixp4xx_i2c_init);
-module_exit(ixp4xx_i2c_exit);
-
-MODULE_DESCRIPTION("GPIO-based I2C adapter for IXP4xx systems");
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
-
projects / kernel / kernel-generic.git / commitdiff