mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
synced 2024-11-16 05:59:41 +02:00
a85c9cccb5
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@9341 3c298f89-4303-0410-b956-a3cf2f4a3e73
198 lines
4.9 KiB
C
198 lines
4.9 KiB
C
/*
|
|
* Custom GPIO-based I2C driver
|
|
*
|
|
* Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* ---------------------------------------------------------------------------
|
|
*
|
|
* The behaviour of this driver can be altered by setting some parameters
|
|
* from the insmod command line.
|
|
*
|
|
* The following parameters are adjustable:
|
|
*
|
|
* bus0 These four arguments can be arrays of
|
|
* bus1 1-8 unsigned integers as follows:
|
|
* bus2
|
|
* bus3 <id>,<sda>,<scl>,<udelay>,<timeout>,<sda_od>,<scl_od>,<scl_oo>
|
|
*
|
|
* where:
|
|
*
|
|
* <id> ID to used as device_id for the corresponding bus (required)
|
|
* <sda> GPIO pin ID to used for SDA (required)
|
|
* <scl> GPIO pin ID to used for SCL (required)
|
|
* <udelay> signal toggle delay.
|
|
* <timeout> clock stretching timeout.
|
|
* <sda_od> SDA is configured as open drain.
|
|
* <scl_od> SCL is configured as open drain.
|
|
* <scl_oo> SCL output drivers cannot be turned off.
|
|
*
|
|
* See include/i2c-gpio.h for more information about the parameters.
|
|
*
|
|
* If this driver is built into the kernel, you can use the following kernel
|
|
* command line parameters, with the same values as the corresponding module
|
|
* parameters listed above:
|
|
*
|
|
* i2c-gpio-custom.bus0
|
|
* i2c-gpio-custom.bus1
|
|
* i2c-gpio-custom.bus2
|
|
* i2c-gpio-custom.bus3
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/platform_device.h>
|
|
|
|
#include <linux/i2c-gpio.h>
|
|
|
|
#define DRV_NAME "i2c-gpio-custom"
|
|
#define DRV_DESC "Custom GPIO-based I2C driver"
|
|
#define DRV_VERSION "0.1.0"
|
|
|
|
#define PFX DRV_NAME ": "
|
|
|
|
#define BUS_PARAM_ID 0
|
|
#define BUS_PARAM_SDA 1
|
|
#define BUS_PARAM_SCL 2
|
|
#define BUS_PARAM_UDELAY 3
|
|
#define BUS_PARAM_TIMEOUT 4
|
|
#define BUS_PARAM_SDA_OD 5
|
|
#define BUS_PARAM_SCL_OD 6
|
|
#define BUS_PARAM_SCL_OO 7
|
|
|
|
#define BUS_PARAM_REQUIRED 3
|
|
#define BUS_PARAM_COUNT 8
|
|
#define BUS_COUNT_MAX 4
|
|
|
|
static unsigned int bus0[BUS_PARAM_COUNT] __initdata;
|
|
static unsigned int bus1[BUS_PARAM_COUNT] __initdata;
|
|
static unsigned int bus2[BUS_PARAM_COUNT] __initdata;
|
|
static unsigned int bus3[BUS_PARAM_COUNT] __initdata;
|
|
|
|
static unsigned int bus_nump[BUS_COUNT_MAX] __initdata;
|
|
|
|
#define BUS_PARM_DESC \
|
|
" config -> id,sda,scl[,udelay,timeout,sda_od,scl_od,scl_oo]"
|
|
|
|
module_param_array(bus0, uint, &bus_nump[0], 0);
|
|
MODULE_PARM_DESC(bus0, "bus0" BUS_PARM_DESC);
|
|
module_param_array(bus1, uint, &bus_nump[1], 0);
|
|
MODULE_PARM_DESC(bus1, "bus1" BUS_PARM_DESC);
|
|
module_param_array(bus2, uint, &bus_nump[2], 0);
|
|
MODULE_PARM_DESC(bus2, "bus2" BUS_PARM_DESC);
|
|
module_param_array(bus3, uint, &bus_nump[3], 0);
|
|
MODULE_PARM_DESC(bus3, "bus3" BUS_PARM_DESC);
|
|
|
|
static struct platform_device *devices[BUS_COUNT_MAX];
|
|
static unsigned int nr_devices;
|
|
|
|
static void i2c_gpio_custom_cleanup(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < nr_devices; i++)
|
|
if (devices[i])
|
|
platform_device_unregister(devices[i]);
|
|
}
|
|
|
|
static int __init i2c_gpio_custom_add_one(unsigned int id, unsigned int *params)
|
|
{
|
|
struct platform_device *pdev;
|
|
struct i2c_gpio_platform_data pdata;
|
|
int err;
|
|
|
|
if (!bus_nump[id])
|
|
return 0;
|
|
|
|
if (bus_nump[id] < BUS_PARAM_REQUIRED) {
|
|
printk(KERN_ERR PFX "not enough parameters for bus%d\n", id);
|
|
err = -EINVAL;
|
|
goto err;
|
|
}
|
|
|
|
pdev = platform_device_alloc("i2c-gpio", params[BUS_PARAM_ID]);
|
|
if (!pdev) {
|
|
err = -ENOMEM;
|
|
goto err;
|
|
}
|
|
|
|
devices[nr_devices++] = pdev;
|
|
|
|
pdata.sda_pin = params[BUS_PARAM_SDA];
|
|
pdata.scl_pin = params[BUS_PARAM_SCL];
|
|
pdata.udelay = params[BUS_PARAM_UDELAY];
|
|
pdata.timeout = params[BUS_PARAM_TIMEOUT];
|
|
pdata.sda_is_open_drain = params[BUS_PARAM_SDA_OD] != 0;
|
|
pdata.scl_is_open_drain = params[BUS_PARAM_SCL_OD] != 0;
|
|
pdata.scl_is_output_only = params[BUS_PARAM_SCL_OO] != 0;
|
|
|
|
err = platform_device_add_data(pdev, &pdata, sizeof(pdata));
|
|
if (err)
|
|
goto err;
|
|
|
|
err = platform_device_register(pdev);
|
|
if (err)
|
|
goto err;
|
|
|
|
return 0;
|
|
|
|
err:
|
|
return err;
|
|
}
|
|
|
|
static int __init i2c_gpio_custom_probe(void)
|
|
{
|
|
int err;
|
|
|
|
printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
|
|
|
|
err = i2c_gpio_custom_add_one(0, bus0);
|
|
if (err) goto err;
|
|
|
|
err = i2c_gpio_custom_add_one(1, bus1);
|
|
if (err) goto err;
|
|
|
|
err = i2c_gpio_custom_add_one(2, bus2);
|
|
if (err) goto err;
|
|
|
|
err = i2c_gpio_custom_add_one(3, bus3);
|
|
if (err) goto err;
|
|
|
|
if (!nr_devices) {
|
|
printk(KERN_ERR PFX "no bus parameter(s) specified\n");
|
|
err = -ENODEV;
|
|
goto err;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err:
|
|
i2c_gpio_custom_cleanup();
|
|
return err;
|
|
}
|
|
|
|
#ifdef MODULE
|
|
static int __init i2c_gpio_custom_init(void)
|
|
{
|
|
return i2c_gpio_custom_probe();
|
|
}
|
|
module_init(i2c_gpio_custom_init);
|
|
|
|
static void __exit i2c_gpio_custom_exit(void)
|
|
{
|
|
i2c_gpio_custom_cleanup();
|
|
}
|
|
module_exit(i2c_gpio_custom_exit);
|
|
#else
|
|
subsys_initcall(i2c_gpio_custom_probe);
|
|
#endif /* MODULE*/
|
|
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org >");
|
|
MODULE_DESCRIPTION(DRV_DESC);
|
|
MODULE_VERSION(DRV_VERSION);
|