openwrt/package/pwm-gpio-custom/src/pwm-gpio-custom.c

219 lines
5.5 KiB
C

/*
* Custom GPIO-based PWM driver
*
* Based on w1-gpio-custom by Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org>
* Copyright (C) 2010 Claudio Mignanti <c.mignanti@gmail.com >
*
* 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 must be arrays
* bus1
* .....
* bus10 <id>,<pin>,<od>
*
* where:
*
* <id> ID to used as device_id for the corresponding bus (required)
* <pin> GPIO pin ID for PWM channel (required)
* *
* 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:
*
* pwm-gpio-custom.bus0
* pwm-gpio-custom.bus1
* pwm-gpio-custom.bunN
* pwm-gpio-custom.bus10
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/workqueue.h>
#include <linux/pwm/pwm.h>
#define DRV_NAME "pwm-gpio-custom"
#define DRV_DESC "Custom GPIO-based pwm driver"
#define DRV_VERSION "0.1.0"
#define PFX DRV_NAME ": "
#define BUS_PARAM_ID 0
#define BUS_PARAM_PIN 1
#define BUS_PARAM_REQUIRED 2
#define BUS_PARAM_COUNT 2
#define BUS_COUNT_MAX 10
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 bus4[BUS_PARAM_COUNT] __initdata;
static unsigned int bus5[BUS_PARAM_COUNT] __initdata;
static unsigned int bus6[BUS_PARAM_COUNT] __initdata;
static unsigned int bus7[BUS_PARAM_COUNT] __initdata;
static unsigned int bus8[BUS_PARAM_COUNT] __initdata;
static unsigned int bus9[BUS_PARAM_COUNT] __initdata;
static unsigned int bus_nump[BUS_COUNT_MAX] __initdata;
#define BUS_PARM_DESC " config -> id,pin"
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);
module_param_array(bus4, uint, &bus_nump[4], 0);
MODULE_PARM_DESC(bus4, "bus4" BUS_PARM_DESC);
module_param_array(bus5, uint, &bus_nump[5], 0);
MODULE_PARM_DESC(bus5, "bus5" BUS_PARM_DESC);
module_param_array(bus6, uint, &bus_nump[6], 0);
MODULE_PARM_DESC(bus6, "bus6" BUS_PARM_DESC);
module_param_array(bus7, uint, &bus_nump[7], 0);
MODULE_PARM_DESC(bus7, "bus7" BUS_PARM_DESC);
module_param_array(bus8, uint, &bus_nump[8], 0);
MODULE_PARM_DESC(bus8, "bus8" BUS_PARM_DESC);
module_param_array(bus9, uint, &bus_nump[9], 0);
MODULE_PARM_DESC(bus9, "bus9" BUS_PARM_DESC);
static struct platform_device *devices[BUS_COUNT_MAX];
static unsigned int nr_devices;
static void pwm_gpio_custom_cleanup(void)
{
int i;
for (i = 0; i < nr_devices; i++)
if (devices[i])
platform_device_put(devices[i]);
}
static int __init pwm_gpio_custom_add_one(unsigned int id, unsigned int *params)
{
struct platform_device *pdev;
struct gpio_pwm_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("gpio_pwm", params[BUS_PARAM_ID]);
if (!pdev) {
err = -ENOMEM;
goto err;
}
pdata.gpio = params[BUS_PARAM_PIN];
err = platform_device_add_data(pdev, &pdata, sizeof(pdata));
if (err)
goto err_put;
err = platform_device_add(pdev);
if (err)
goto err_put;
devices[nr_devices++] = pdev;
return 0;
err_put:
platform_device_put(pdev);
err:
return err;
}
static int __init pwm_gpio_custom_probe(void)
{
int err;
nr_devices = 0;
printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
err = pwm_gpio_custom_add_one(0, bus0);
if (err) goto err;
err = pwm_gpio_custom_add_one(1, bus1);
if (err) goto err;
err = pwm_gpio_custom_add_one(2, bus2);
if (err) goto err;
err = pwm_gpio_custom_add_one(3, bus3);
if (err) goto err;
err = pwm_gpio_custom_add_one(4, bus4);
if (err) goto err;
err = pwm_gpio_custom_add_one(5, bus5);
if (err) goto err;
err = pwm_gpio_custom_add_one(6, bus6);
if (err) goto err;
err = pwm_gpio_custom_add_one(7, bus7);
if (err) goto err;
err = pwm_gpio_custom_add_one(8, bus8);
if (err) goto err;
err = pwm_gpio_custom_add_one(9, bus9);
if (err) goto err;
if (!nr_devices) {
printk(KERN_ERR PFX "no bus parameter(s) specified\n");
err = -ENODEV;
goto err;
}
return 0;
err:
pwm_gpio_custom_cleanup();
return err;
}
#ifdef MODULE
static int __init pwm_gpio_custom_init(void)
{
return pwm_gpio_custom_probe();
}
module_init(pwm_gpio_custom_init);
static void __exit pwm_gpio_custom_exit(void)
{
pwm_gpio_custom_cleanup();
}
module_exit(pwm_gpio_custom_exit);
#else
subsys_initcall(pwm_gpio_custom_probe);
#endif /* MODULE*/
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Bifferos <bifferos at yahoo.co.uk >");
MODULE_AUTHOR("Claudio Mignanti <c.mignanti@gmail.com >");
MODULE_DESCRIPTION(DRV_DESC);
MODULE_VERSION(DRV_VERSION);