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openwrt-xburst/target/linux/ubicom32/files/drivers/video/backlight/ubicom32bl.c
kaloz 1a29ef8e97 [ubicom32]: move new files out from platform support patch
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@19815 3c298f89-4303-0410-b956-a3cf2f4a3e73
2010-02-22 13:54:47 +00:00

400 lines
8.5 KiB
C

/*
* drivers/video/backlight/ubicom32bl.c
* Backlight driver for the Ubicom32 platform
*
* (C) Copyright 2009, Ubicom, Inc.
*
* This file is part of the Ubicom32 Linux Kernel Port.
*
* The Ubicom32 Linux Kernel Port 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, either version 2 of the
* License, or (at your option) any later version.
*
* The Ubicom32 Linux Kernel Port is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with the Ubicom32 Linux Kernel Port. If not,
* see <http://www.gnu.org/licenses/>.
*
* Ubicom32 implementation derived from (with many thanks):
* arch/m68knommu
* arch/blackfin
* arch/parisc
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/backlight.h>
#include <linux/fb.h>
#include <asm/ubicom32bl.h>
#include <asm/ip5000.h>
#define DRIVER_NAME "ubicom32bl"
#define UBICOM32BL_MAX_BRIGHTNESS 255
struct ubicom32bl_data {
/*
* Pointer to the platform data structure. Keep this around since we need values
* from it to set the backlight intensity.
*/
const struct ubicom32bl_platform_data *pdata;
/*
* Backlight device, we have to save this for use when we remove ourselves.
*/
struct backlight_device *bldev;
/*
* Current intensity, used for get_intensity.
*/
int cur_intensity;
/*
* Init function for PWM
*/
int (*init_fn)(struct ubicom32bl_data *);
/*
* Set intensity function depending on the backlight type
*/
int (*set_intensity_fn)(struct ubicom32bl_data *, int);
};
/*
* ubicom32bl_set_intensity_gpio
*/
static int ubicom32bl_set_intensity_gpio(struct ubicom32bl_data *ud, int intensity)
{
ud->cur_intensity = intensity ? 255 : 0;
if (intensity) {
// set gpio
return 0;
}
// clear gpio
return 0;
}
/*
* ubicom32bl_set_intensity_hw
*/
static int ubicom32bl_set_intensity_hw(struct ubicom32bl_data *ud, int intensity)
{
u16_t period = ud->pdata->pwm_period;
u16_t duty;
/*
* Calculate the new duty cycle
*/
duty = (period * intensity) / (UBICOM32BL_MAX_BRIGHTNESS + 1);
/*
* Set the new duty cycle
*/
switch (ud->pdata->pwm_channel) {
case 0:
/*
* Channel 0 is in the lower half of PORT C ctl0 and ctl1
*/
UBICOM32_IO_PORT(RC)->ctl1 = (ud->pdata->pwm_period << 16) | duty;
break;
case 1:
/*
* Channel 1 is in the upper half of PORT C ctl0 and ctl2
*/
UBICOM32_IO_PORT(RC)->ctl2 = (ud->pdata->pwm_period << 16) | duty;
break;
case 2:
/*
* Channel 2 is in PORT H ctl0 and ctl1
*/
UBICOM32_IO_PORT(RH)->ctl1 = (ud->pdata->pwm_period << 16) | duty;
break;
}
ud->cur_intensity = intensity;
return 0;
}
/*
* ubicom32bl_set_intensity
*/
static int ubicom32bl_set_intensity(struct backlight_device *bd)
{
struct ubicom32bl_data *ud = (struct ubicom32bl_data *)bl_get_data(bd);
int intensity = bd->props.brightness;
/*
* If we're blanked the the intensity doesn't matter.
*/
if ((bd->props.power != FB_BLANK_UNBLANK) || (bd->props.fb_blank != FB_BLANK_UNBLANK)) {
intensity = 0;
}
/*
* Check for inverted backlight.
*/
if (ud->pdata->invert) {
intensity = UBICOM32BL_MAX_BRIGHTNESS - intensity;
}
if (ud->set_intensity_fn) {
return ud->set_intensity_fn(ud, intensity);
}
return -ENXIO;
}
/*
* ubicom32bl_get_intensity
* Return the current intensity of the backlight.
*/
static int ubicom32bl_get_intensity(struct backlight_device *bd)
{
struct ubicom32bl_data *ud = (struct ubicom32bl_data *)bl_get_data(bd);
return ud->cur_intensity;
}
/*
* ubicom32bl_init_hw_pwm
* Set the appropriate PWM registers
*/
static int ubicom32bl_init_hw_pwm(struct ubicom32bl_data *ud)
{
/*
* bit 13: enable
*/
u16_t pwm_cfg = (1 << 13) | (ud->pdata->pwm_prescale << 8) ;
switch (ud->pdata->pwm_channel) {
case 0:
/*
* Channel 0 is in the lower half of PORT C ctl0 and ctl1 (PA5)
*/
UBICOM32_IO_PORT(RC)->ctl0 &= ~0xFFFF;
UBICOM32_IO_PORT(RC)->ctl0 |= pwm_cfg;
UBICOM32_IO_PORT(RC)->ctl1 = ud->pdata->pwm_period << 16;
/*
* If the port function is not set, set it to GPIO/PWM
*/
if (!UBICOM32_IO_PORT(RA)->function) {
UBICOM32_IO_PORT(RA)->function = 3;
}
break;
case 1:
/*
* Channel 1 is in the upper half of PORT C ctl0 and ctl2 (PE4)
*/
UBICOM32_IO_PORT(RC)->ctl0 &= ~0xFFFF0000;
UBICOM32_IO_PORT(RC)->ctl0 |= (pwm_cfg << 16);
UBICOM32_IO_PORT(RC)->ctl2 = ud->pdata->pwm_period << 16;
/*
* If the port function is not set, set it to GPIO/ExtIOInt
*/
if (!UBICOM32_IO_PORT(RE)->function) {
UBICOM32_IO_PORT(RE)->function = 3;
}
break;
case 2:
/*
* Channel 2 is in PORT H ctl0 and ctl1 (PD0)
*/
UBICOM32_IO_PORT(RH)->ctl0 &= ~0xFFFF0000;
UBICOM32_IO_PORT(RH)->ctl0 = pwm_cfg;
UBICOM32_IO_PORT(RH)->ctl1 = ud->pdata->pwm_period << 16;
/*
* If the port function is not set, set it to GPIO
*/
if (!UBICOM32_IO_PORT(RD)->function) {
UBICOM32_IO_PORT(RD)->function = 3;
}
break;
}
return 0;
}
/*
* ubicom32bl_init_gpio
* Allocate the appropriate GPIO
*/
static int ubicom32bl_init_gpio(struct ubicom32bl_data *ud)
{
return 0;
}
static struct backlight_ops ubicom32bl_ops = {
.get_brightness = ubicom32bl_get_intensity,
.update_status = ubicom32bl_set_intensity,
};
/*
* ubicom32bl_probe
*/
static int ubicom32bl_probe(struct platform_device *pdev)
{
const struct ubicom32bl_platform_data *pdata = pdev->dev.platform_data;
struct ubicom32bl_data *ud;
struct backlight_device *bldev;
int retval;
/*
* Check to see if we have any platform data, if we don't then the backlight is not
* configured on this device.
*/
if (!pdata) {
return -ENODEV;
}
/*
* Allocate our private data
*/
ud = kzalloc(sizeof(struct ubicom32bl_data), GFP_KERNEL);
if (!ud) {
return -ENOMEM;
}
ud->pdata = pdata;
/*
* Check to see that the platform data is valid for this driver
*/
switch (pdata->type) {
case UBICOM32BL_TYPE_PWM:
{
/*
* Make sure we have a PWM peripheral
*/
u32_t chipid;
asm volatile (
"move.4 %0, CHIP_ID \n\t"
: "=r" (chipid)
);
if (chipid != 0x00030001) {
retval = -ENODEV;
goto fail;
}
if (pdata->pwm_channel > 3) {
retval = -ENODEV;
goto fail;
}
if (pdata->pwm_prescale > 16) {
retval = -EINVAL;
goto fail;
}
ud->init_fn = ubicom32bl_init_hw_pwm;
ud->set_intensity_fn = ubicom32bl_set_intensity_hw;
break;
}
case UBICOM32BL_TYPE_PWM_HRT:
// For now, PWM HRT devices are treated as binary lights.
case UBICOM32BL_TYPE_BINARY:
ud->init_fn = ubicom32bl_init_gpio;
ud->set_intensity_fn = ubicom32bl_set_intensity_gpio;
break;
}
/*
* Register our backlight device
*/
bldev = backlight_device_register(DRIVER_NAME, &pdev->dev, ud, &ubicom32bl_ops);
if (IS_ERR(bldev)) {
retval = PTR_ERR(bldev);
goto fail;
}
ud->bldev = bldev;
ud->cur_intensity = pdata->default_intensity;
platform_set_drvdata(pdev, ud);
/*
* Start up the backlight at the prescribed default intensity
*/
bldev->props.power = FB_BLANK_UNBLANK;
bldev->props.max_brightness = UBICOM32BL_MAX_BRIGHTNESS;
bldev->props.brightness = pdata->default_intensity;
if (ud->init_fn) {
if (ud->init_fn(ud) != 0) {
retval = -ENODEV;
backlight_device_unregister(ud->bldev);
goto fail;
}
}
ubicom32bl_set_intensity(bldev);
printk(KERN_INFO DRIVER_NAME ": Backlight driver started\n");
return 0;
fail:
platform_set_drvdata(pdev, NULL);
kfree(ud);
return retval;
}
/*
* ubicom32bl_remove
*/
static int __exit ubicom32bl_remove(struct platform_device *pdev)
{
struct ubicom32bl_data *ud = platform_get_drvdata(pdev);
backlight_device_unregister(ud->bldev);
platform_set_drvdata(pdev, NULL);
kfree(ud);
return 0;
}
static struct platform_driver ubicom32bl_driver = {
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
},
.remove = __exit_p(ubicom32bl_remove),
};
/*
* ubicom32bl_init
*/
static int __init ubicom32bl_init(void)
{
return platform_driver_probe(&ubicom32bl_driver, ubicom32bl_probe);
}
module_init(ubicom32bl_init);
/*
* ubicom32bl_exit
*/
static void __exit ubicom32bl_exit(void)
{
platform_driver_unregister(&ubicom32bl_driver);
}
module_exit(ubicom32bl_exit);
MODULE_AUTHOR("Patrick Tjin <@ubicom.com>");
MODULE_DESCRIPTION("Ubicom32 backlight driver");
MODULE_LICENSE("GPL");