mirror of https://github.com/hak5/openwrt.git
400 lines
8.5 KiB
C
400 lines
8.5 KiB
C
/*
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* drivers/video/backlight/ubicom32bl.c
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* Backlight driver for the Ubicom32 platform
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*
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* (C) Copyright 2009, Ubicom, Inc.
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*
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* This file is part of the Ubicom32 Linux Kernel Port.
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*
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* The Ubicom32 Linux Kernel Port is free software: you can redistribute
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* it and/or modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, either version 2 of the
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* License, or (at your option) any later version.
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*
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* The Ubicom32 Linux Kernel Port is distributed in the hope that it
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* will be useful, but WITHOUT ANY WARRANTY; without even the implied
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* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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* the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with the Ubicom32 Linux Kernel Port. If not,
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* see <http://www.gnu.org/licenses/>.
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*
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* Ubicom32 implementation derived from (with many thanks):
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* arch/m68knommu
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* arch/blackfin
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* arch/parisc
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/backlight.h>
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#include <linux/fb.h>
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#include <asm/ubicom32bl.h>
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#include <asm/ip5000.h>
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#define DRIVER_NAME "ubicom32bl"
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#define UBICOM32BL_MAX_BRIGHTNESS 255
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struct ubicom32bl_data {
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/*
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* Pointer to the platform data structure. Keep this around since we need values
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* from it to set the backlight intensity.
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*/
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const struct ubicom32bl_platform_data *pdata;
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/*
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* Backlight device, we have to save this for use when we remove ourselves.
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*/
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struct backlight_device *bldev;
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/*
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* Current intensity, used for get_intensity.
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*/
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int cur_intensity;
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/*
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* Init function for PWM
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*/
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int (*init_fn)(struct ubicom32bl_data *);
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/*
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* Set intensity function depending on the backlight type
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*/
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int (*set_intensity_fn)(struct ubicom32bl_data *, int);
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};
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/*
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* ubicom32bl_set_intensity_gpio
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*/
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static int ubicom32bl_set_intensity_gpio(struct ubicom32bl_data *ud, int intensity)
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{
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ud->cur_intensity = intensity ? 255 : 0;
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if (intensity) {
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// set gpio
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return 0;
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}
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// clear gpio
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return 0;
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}
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/*
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* ubicom32bl_set_intensity_hw
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*/
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static int ubicom32bl_set_intensity_hw(struct ubicom32bl_data *ud, int intensity)
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{
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u16_t period = ud->pdata->pwm_period;
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u16_t duty;
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/*
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* Calculate the new duty cycle
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*/
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duty = (period * intensity) / (UBICOM32BL_MAX_BRIGHTNESS + 1);
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/*
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* Set the new duty cycle
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*/
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switch (ud->pdata->pwm_channel) {
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case 0:
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/*
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* Channel 0 is in the lower half of PORT C ctl0 and ctl1
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*/
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UBICOM32_IO_PORT(RC)->ctl1 = (ud->pdata->pwm_period << 16) | duty;
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break;
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case 1:
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/*
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* Channel 1 is in the upper half of PORT C ctl0 and ctl2
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*/
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UBICOM32_IO_PORT(RC)->ctl2 = (ud->pdata->pwm_period << 16) | duty;
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break;
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case 2:
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/*
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* Channel 2 is in PORT H ctl0 and ctl1
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*/
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UBICOM32_IO_PORT(RH)->ctl1 = (ud->pdata->pwm_period << 16) | duty;
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break;
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}
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ud->cur_intensity = intensity;
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return 0;
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}
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/*
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* ubicom32bl_set_intensity
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*/
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static int ubicom32bl_set_intensity(struct backlight_device *bd)
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{
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struct ubicom32bl_data *ud = (struct ubicom32bl_data *)bl_get_data(bd);
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int intensity = bd->props.brightness;
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/*
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* If we're blanked the the intensity doesn't matter.
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*/
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if ((bd->props.power != FB_BLANK_UNBLANK) || (bd->props.fb_blank != FB_BLANK_UNBLANK)) {
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intensity = 0;
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}
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/*
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* Check for inverted backlight.
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*/
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if (ud->pdata->invert) {
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intensity = UBICOM32BL_MAX_BRIGHTNESS - intensity;
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}
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if (ud->set_intensity_fn) {
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return ud->set_intensity_fn(ud, intensity);
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}
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return -ENXIO;
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}
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/*
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* ubicom32bl_get_intensity
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* Return the current intensity of the backlight.
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*/
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static int ubicom32bl_get_intensity(struct backlight_device *bd)
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{
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struct ubicom32bl_data *ud = (struct ubicom32bl_data *)bl_get_data(bd);
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return ud->cur_intensity;
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}
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/*
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* ubicom32bl_init_hw_pwm
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* Set the appropriate PWM registers
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*/
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static int ubicom32bl_init_hw_pwm(struct ubicom32bl_data *ud)
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{
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/*
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* bit 13: enable
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*/
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u16_t pwm_cfg = (1 << 13) | (ud->pdata->pwm_prescale << 8) ;
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switch (ud->pdata->pwm_channel) {
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case 0:
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/*
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* Channel 0 is in the lower half of PORT C ctl0 and ctl1 (PA5)
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*/
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UBICOM32_IO_PORT(RC)->ctl0 &= ~0xFFFF;
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UBICOM32_IO_PORT(RC)->ctl0 |= pwm_cfg;
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UBICOM32_IO_PORT(RC)->ctl1 = ud->pdata->pwm_period << 16;
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/*
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* If the port function is not set, set it to GPIO/PWM
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*/
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if (!UBICOM32_IO_PORT(RA)->function) {
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UBICOM32_IO_PORT(RA)->function = 3;
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}
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break;
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case 1:
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/*
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* Channel 1 is in the upper half of PORT C ctl0 and ctl2 (PE4)
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*/
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UBICOM32_IO_PORT(RC)->ctl0 &= ~0xFFFF0000;
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UBICOM32_IO_PORT(RC)->ctl0 |= (pwm_cfg << 16);
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UBICOM32_IO_PORT(RC)->ctl2 = ud->pdata->pwm_period << 16;
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/*
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* If the port function is not set, set it to GPIO/ExtIOInt
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*/
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if (!UBICOM32_IO_PORT(RE)->function) {
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UBICOM32_IO_PORT(RE)->function = 3;
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}
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break;
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case 2:
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/*
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* Channel 2 is in PORT H ctl0 and ctl1 (PD0)
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*/
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UBICOM32_IO_PORT(RH)->ctl0 &= ~0xFFFF0000;
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UBICOM32_IO_PORT(RH)->ctl0 = pwm_cfg;
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UBICOM32_IO_PORT(RH)->ctl1 = ud->pdata->pwm_period << 16;
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/*
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* If the port function is not set, set it to GPIO
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*/
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if (!UBICOM32_IO_PORT(RD)->function) {
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UBICOM32_IO_PORT(RD)->function = 3;
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}
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break;
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}
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return 0;
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}
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/*
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* ubicom32bl_init_gpio
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* Allocate the appropriate GPIO
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*/
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static int ubicom32bl_init_gpio(struct ubicom32bl_data *ud)
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{
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return 0;
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}
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static struct backlight_ops ubicom32bl_ops = {
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.get_brightness = ubicom32bl_get_intensity,
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.update_status = ubicom32bl_set_intensity,
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};
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/*
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* ubicom32bl_probe
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*/
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static int ubicom32bl_probe(struct platform_device *pdev)
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{
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const struct ubicom32bl_platform_data *pdata = pdev->dev.platform_data;
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struct ubicom32bl_data *ud;
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struct backlight_device *bldev;
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int retval;
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/*
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* Check to see if we have any platform data, if we don't then the backlight is not
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* configured on this device.
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*/
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if (!pdata) {
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return -ENODEV;
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}
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/*
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* Allocate our private data
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*/
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ud = kzalloc(sizeof(struct ubicom32bl_data), GFP_KERNEL);
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if (!ud) {
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return -ENOMEM;
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}
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ud->pdata = pdata;
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/*
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* Check to see that the platform data is valid for this driver
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*/
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switch (pdata->type) {
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case UBICOM32BL_TYPE_PWM:
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{
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/*
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* Make sure we have a PWM peripheral
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*/
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u32_t chipid;
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asm volatile (
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"move.4 %0, CHIP_ID \n\t"
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: "=r" (chipid)
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);
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if (chipid != 0x00030001) {
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retval = -ENODEV;
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goto fail;
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}
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if (pdata->pwm_channel > 3) {
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retval = -ENODEV;
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goto fail;
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}
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if (pdata->pwm_prescale > 16) {
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retval = -EINVAL;
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goto fail;
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}
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ud->init_fn = ubicom32bl_init_hw_pwm;
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ud->set_intensity_fn = ubicom32bl_set_intensity_hw;
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break;
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}
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case UBICOM32BL_TYPE_PWM_HRT:
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// For now, PWM HRT devices are treated as binary lights.
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case UBICOM32BL_TYPE_BINARY:
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ud->init_fn = ubicom32bl_init_gpio;
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ud->set_intensity_fn = ubicom32bl_set_intensity_gpio;
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break;
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}
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/*
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* Register our backlight device
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*/
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bldev = backlight_device_register(DRIVER_NAME, &pdev->dev, ud, &ubicom32bl_ops);
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if (IS_ERR(bldev)) {
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retval = PTR_ERR(bldev);
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goto fail;
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}
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ud->bldev = bldev;
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ud->cur_intensity = pdata->default_intensity;
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platform_set_drvdata(pdev, ud);
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/*
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* Start up the backlight at the prescribed default intensity
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*/
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bldev->props.power = FB_BLANK_UNBLANK;
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bldev->props.max_brightness = UBICOM32BL_MAX_BRIGHTNESS;
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bldev->props.brightness = pdata->default_intensity;
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if (ud->init_fn) {
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if (ud->init_fn(ud) != 0) {
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retval = -ENODEV;
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backlight_device_unregister(ud->bldev);
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goto fail;
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}
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}
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ubicom32bl_set_intensity(bldev);
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printk(KERN_INFO DRIVER_NAME ": Backlight driver started\n");
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return 0;
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fail:
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platform_set_drvdata(pdev, NULL);
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kfree(ud);
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return retval;
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}
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/*
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* ubicom32bl_remove
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*/
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static int __exit ubicom32bl_remove(struct platform_device *pdev)
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{
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struct ubicom32bl_data *ud = platform_get_drvdata(pdev);
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backlight_device_unregister(ud->bldev);
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platform_set_drvdata(pdev, NULL);
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kfree(ud);
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return 0;
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}
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static struct platform_driver ubicom32bl_driver = {
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.driver = {
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.name = DRIVER_NAME,
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.owner = THIS_MODULE,
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},
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.remove = __exit_p(ubicom32bl_remove),
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};
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/*
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* ubicom32bl_init
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*/
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static int __init ubicom32bl_init(void)
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{
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return platform_driver_probe(&ubicom32bl_driver, ubicom32bl_probe);
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}
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module_init(ubicom32bl_init);
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/*
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* ubicom32bl_exit
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*/
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static void __exit ubicom32bl_exit(void)
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{
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platform_driver_unregister(&ubicom32bl_driver);
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}
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module_exit(ubicom32bl_exit);
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MODULE_AUTHOR("Patrick Tjin <@ubicom.com>");
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MODULE_DESCRIPTION("Ubicom32 backlight driver");
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MODULE_LICENSE("GPL");
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