493 lines
12 KiB
C
493 lines
12 KiB
C
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/*
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* AS3711 PMIC backlight driver, using DCDC Step Up Converters
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*
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* Copyright (C) 2012 Renesas Electronics Corporation
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* Author: Guennadi Liakhovetski, <g.liakhovetski@gmx.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the version 2 of the GNU General Public License as
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* published by the Free Software Foundation
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*/
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#include <linux/backlight.h>
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#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/fb.h>
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#include <linux/kernel.h>
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#include <linux/mfd/as3711.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/slab.h>
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enum as3711_bl_type {
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AS3711_BL_SU1,
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AS3711_BL_SU2,
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};
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struct as3711_bl_data {
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bool powered;
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const char *fb_name;
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struct device *fb_dev;
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enum as3711_bl_type type;
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int brightness;
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struct backlight_device *bl;
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};
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struct as3711_bl_supply {
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struct as3711_bl_data su1;
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struct as3711_bl_data su2;
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const struct as3711_bl_pdata *pdata;
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struct as3711 *as3711;
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};
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static struct as3711_bl_supply *to_supply(struct as3711_bl_data *su)
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{
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switch (su->type) {
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case AS3711_BL_SU1:
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return container_of(su, struct as3711_bl_supply, su1);
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case AS3711_BL_SU2:
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return container_of(su, struct as3711_bl_supply, su2);
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}
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return NULL;
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}
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static int as3711_set_brightness_auto_i(struct as3711_bl_data *data,
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unsigned int brightness)
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{
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struct as3711_bl_supply *supply = to_supply(data);
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struct as3711 *as3711 = supply->as3711;
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const struct as3711_bl_pdata *pdata = supply->pdata;
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int ret = 0;
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/* Only all equal current values are supported */
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if (pdata->su2_auto_curr1)
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ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE,
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brightness);
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if (!ret && pdata->su2_auto_curr2)
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ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE,
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brightness);
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if (!ret && pdata->su2_auto_curr3)
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ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE,
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brightness);
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return ret;
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}
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static int as3711_set_brightness_v(struct as3711 *as3711,
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unsigned int brightness,
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unsigned int reg)
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{
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if (brightness > 31)
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return -EINVAL;
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return regmap_update_bits(as3711->regmap, reg, 0xf0,
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brightness << 4);
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}
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static int as3711_bl_su2_reset(struct as3711_bl_supply *supply)
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{
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struct as3711 *as3711 = supply->as3711;
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int ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_5,
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3, supply->pdata->su2_fbprot);
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if (!ret)
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ret = regmap_update_bits(as3711->regmap,
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AS3711_STEPUP_CONTROL_2, 1, 0);
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if (!ret)
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ret = regmap_update_bits(as3711->regmap,
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AS3711_STEPUP_CONTROL_2, 1, 1);
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return ret;
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}
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/*
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* Someone with less fragile or less expensive hardware could try to simplify
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* the brightness adjustment procedure.
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*/
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static int as3711_bl_update_status(struct backlight_device *bl)
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{
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struct as3711_bl_data *data = bl_get_data(bl);
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struct as3711_bl_supply *supply = to_supply(data);
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struct as3711 *as3711 = supply->as3711;
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int brightness = bl->props.brightness;
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int ret = 0;
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dev_dbg(&bl->dev, "%s(): brightness %u, pwr %x, blank %x, state %x\n",
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__func__, bl->props.brightness, bl->props.power,
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bl->props.fb_blank, bl->props.state);
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if (bl->props.power != FB_BLANK_UNBLANK ||
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bl->props.fb_blank != FB_BLANK_UNBLANK ||
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bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
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brightness = 0;
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if (data->type == AS3711_BL_SU1) {
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ret = as3711_set_brightness_v(as3711, brightness,
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AS3711_STEPUP_CONTROL_1);
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} else {
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const struct as3711_bl_pdata *pdata = supply->pdata;
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switch (pdata->su2_feedback) {
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case AS3711_SU2_VOLTAGE:
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ret = as3711_set_brightness_v(as3711, brightness,
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AS3711_STEPUP_CONTROL_2);
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break;
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case AS3711_SU2_CURR_AUTO:
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ret = as3711_set_brightness_auto_i(data, brightness / 4);
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if (ret < 0)
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return ret;
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if (brightness) {
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ret = as3711_bl_su2_reset(supply);
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if (ret < 0)
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return ret;
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udelay(500);
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ret = as3711_set_brightness_auto_i(data, brightness);
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} else {
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ret = regmap_update_bits(as3711->regmap,
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AS3711_STEPUP_CONTROL_2, 1, 0);
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}
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break;
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/* Manual one current feedback pin below */
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case AS3711_SU2_CURR1:
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ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE,
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brightness);
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break;
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case AS3711_SU2_CURR2:
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ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE,
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brightness);
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break;
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case AS3711_SU2_CURR3:
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ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE,
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brightness);
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break;
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default:
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ret = -EINVAL;
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}
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}
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if (!ret)
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data->brightness = brightness;
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return ret;
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}
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static int as3711_bl_get_brightness(struct backlight_device *bl)
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{
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struct as3711_bl_data *data = bl_get_data(bl);
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return data->brightness;
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}
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static const struct backlight_ops as3711_bl_ops = {
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.update_status = as3711_bl_update_status,
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.get_brightness = as3711_bl_get_brightness,
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};
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static int as3711_bl_init_su2(struct as3711_bl_supply *supply)
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{
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struct as3711 *as3711 = supply->as3711;
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const struct as3711_bl_pdata *pdata = supply->pdata;
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u8 ctl = 0;
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int ret;
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dev_dbg(as3711->dev, "%s(): use %u\n", __func__, pdata->su2_feedback);
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/* Turn SU2 off */
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ret = regmap_write(as3711->regmap, AS3711_STEPUP_CONTROL_2, 0);
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if (ret < 0)
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return ret;
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switch (pdata->su2_feedback) {
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case AS3711_SU2_VOLTAGE:
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ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 0);
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break;
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case AS3711_SU2_CURR1:
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ctl = 1;
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ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 1);
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break;
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case AS3711_SU2_CURR2:
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ctl = 4;
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ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 2);
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break;
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case AS3711_SU2_CURR3:
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ctl = 0x10;
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ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 3);
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break;
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case AS3711_SU2_CURR_AUTO:
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if (pdata->su2_auto_curr1)
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ctl = 2;
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if (pdata->su2_auto_curr2)
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ctl |= 8;
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if (pdata->su2_auto_curr3)
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ctl |= 0x20;
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ret = 0;
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break;
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default:
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return -EINVAL;
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}
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if (!ret)
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ret = regmap_write(as3711->regmap, AS3711_CURR_CONTROL, ctl);
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return ret;
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}
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static int as3711_bl_register(struct platform_device *pdev,
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unsigned int max_brightness, struct as3711_bl_data *su)
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{
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struct backlight_properties props = {.type = BACKLIGHT_RAW,};
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struct backlight_device *bl;
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/* max tuning I = 31uA for voltage- and 38250uA for current-feedback */
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props.max_brightness = max_brightness;
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bl = devm_backlight_device_register(&pdev->dev,
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su->type == AS3711_BL_SU1 ?
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"as3711-su1" : "as3711-su2",
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&pdev->dev, su,
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&as3711_bl_ops, &props);
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if (IS_ERR(bl)) {
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dev_err(&pdev->dev, "failed to register backlight\n");
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return PTR_ERR(bl);
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}
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bl->props.brightness = props.max_brightness;
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backlight_update_status(bl);
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su->bl = bl;
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return 0;
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}
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static int as3711_backlight_parse_dt(struct device *dev)
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{
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struct as3711_bl_pdata *pdata = dev_get_platdata(dev);
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struct device_node *bl, *fb;
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int ret;
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bl = of_get_child_by_name(dev->parent->of_node, "backlight");
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if (!bl) {
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dev_dbg(dev, "backlight node not found\n");
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return -ENODEV;
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}
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fb = of_parse_phandle(bl, "su1-dev", 0);
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if (fb) {
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pdata->su1_fb = fb->full_name;
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ret = of_property_read_u32(bl, "su1-max-uA", &pdata->su1_max_uA);
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if (pdata->su1_max_uA <= 0)
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ret = -EINVAL;
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if (ret < 0)
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goto err_put_bl;
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}
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fb = of_parse_phandle(bl, "su2-dev", 0);
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if (fb) {
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int count = 0;
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pdata->su2_fb = fb->full_name;
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ret = of_property_read_u32(bl, "su2-max-uA", &pdata->su2_max_uA);
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if (pdata->su2_max_uA <= 0)
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ret = -EINVAL;
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if (ret < 0)
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goto err_put_bl;
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if (of_find_property(bl, "su2-feedback-voltage", NULL)) {
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pdata->su2_feedback = AS3711_SU2_VOLTAGE;
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count++;
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}
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if (of_find_property(bl, "su2-feedback-curr1", NULL)) {
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pdata->su2_feedback = AS3711_SU2_CURR1;
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count++;
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}
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if (of_find_property(bl, "su2-feedback-curr2", NULL)) {
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pdata->su2_feedback = AS3711_SU2_CURR2;
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count++;
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}
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if (of_find_property(bl, "su2-feedback-curr3", NULL)) {
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pdata->su2_feedback = AS3711_SU2_CURR3;
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count++;
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}
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if (of_find_property(bl, "su2-feedback-curr-auto", NULL)) {
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pdata->su2_feedback = AS3711_SU2_CURR_AUTO;
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count++;
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}
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if (count != 1) {
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ret = -EINVAL;
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goto err_put_bl;
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}
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count = 0;
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if (of_find_property(bl, "su2-fbprot-lx-sd4", NULL)) {
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pdata->su2_fbprot = AS3711_SU2_LX_SD4;
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count++;
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}
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if (of_find_property(bl, "su2-fbprot-gpio2", NULL)) {
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pdata->su2_fbprot = AS3711_SU2_GPIO2;
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count++;
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}
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if (of_find_property(bl, "su2-fbprot-gpio3", NULL)) {
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pdata->su2_fbprot = AS3711_SU2_GPIO3;
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count++;
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}
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if (of_find_property(bl, "su2-fbprot-gpio4", NULL)) {
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pdata->su2_fbprot = AS3711_SU2_GPIO4;
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count++;
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}
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if (count != 1) {
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ret = -EINVAL;
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goto err_put_bl;
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}
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count = 0;
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if (of_find_property(bl, "su2-auto-curr1", NULL)) {
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pdata->su2_auto_curr1 = true;
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count++;
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}
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if (of_find_property(bl, "su2-auto-curr2", NULL)) {
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pdata->su2_auto_curr2 = true;
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count++;
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}
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if (of_find_property(bl, "su2-auto-curr3", NULL)) {
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pdata->su2_auto_curr3 = true;
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count++;
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}
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/*
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|
* At least one su2-auto-curr* must be specified iff
|
||
|
|
* AS3711_SU2_CURR_AUTO is used
|
||
|
|
*/
|
||
|
|
if (!count ^ (pdata->su2_feedback != AS3711_SU2_CURR_AUTO)) {
|
||
|
|
ret = -EINVAL;
|
||
|
|
goto err_put_bl;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
of_node_put(bl);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
err_put_bl:
|
||
|
|
of_node_put(bl);
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int as3711_backlight_probe(struct platform_device *pdev)
|
||
|
|
{
|
||
|
|
struct as3711_bl_pdata *pdata = dev_get_platdata(&pdev->dev);
|
||
|
|
struct as3711 *as3711 = dev_get_drvdata(pdev->dev.parent);
|
||
|
|
struct as3711_bl_supply *supply;
|
||
|
|
struct as3711_bl_data *su;
|
||
|
|
unsigned int max_brightness;
|
||
|
|
int ret;
|
||
|
|
|
||
|
|
if (!pdata) {
|
||
|
|
dev_err(&pdev->dev, "No platform data, exiting...\n");
|
||
|
|
return -ENODEV;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (pdev->dev.parent->of_node) {
|
||
|
|
ret = as3711_backlight_parse_dt(&pdev->dev);
|
||
|
|
if (ret < 0) {
|
||
|
|
dev_err(&pdev->dev, "DT parsing failed: %d\n", ret);
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!pdata->su1_fb && !pdata->su2_fb) {
|
||
|
|
dev_err(&pdev->dev, "No framebuffer specified\n");
|
||
|
|
return -EINVAL;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Due to possible hardware damage I chose to block all modes,
|
||
|
|
* unsupported on my hardware. Anyone, wishing to use any of those modes
|
||
|
|
* will have to first review the code, then activate and test it.
|
||
|
|
*/
|
||
|
|
if (pdata->su1_fb ||
|
||
|
|
pdata->su2_fbprot != AS3711_SU2_GPIO4 ||
|
||
|
|
pdata->su2_feedback != AS3711_SU2_CURR_AUTO) {
|
||
|
|
dev_warn(&pdev->dev,
|
||
|
|
"Attention! An untested mode has been chosen!\n"
|
||
|
|
"Please, review the code, enable, test, and report success:-)\n");
|
||
|
|
return -EINVAL;
|
||
|
|
}
|
||
|
|
|
||
|
|
supply = devm_kzalloc(&pdev->dev, sizeof(*supply), GFP_KERNEL);
|
||
|
|
if (!supply)
|
||
|
|
return -ENOMEM;
|
||
|
|
|
||
|
|
supply->as3711 = as3711;
|
||
|
|
supply->pdata = pdata;
|
||
|
|
|
||
|
|
if (pdata->su1_fb) {
|
||
|
|
su = &supply->su1;
|
||
|
|
su->fb_name = pdata->su1_fb;
|
||
|
|
su->type = AS3711_BL_SU1;
|
||
|
|
|
||
|
|
max_brightness = min(pdata->su1_max_uA, 31);
|
||
|
|
ret = as3711_bl_register(pdev, max_brightness, su);
|
||
|
|
if (ret < 0)
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (pdata->su2_fb) {
|
||
|
|
su = &supply->su2;
|
||
|
|
su->fb_name = pdata->su2_fb;
|
||
|
|
su->type = AS3711_BL_SU2;
|
||
|
|
|
||
|
|
switch (pdata->su2_fbprot) {
|
||
|
|
case AS3711_SU2_GPIO2:
|
||
|
|
case AS3711_SU2_GPIO3:
|
||
|
|
case AS3711_SU2_GPIO4:
|
||
|
|
case AS3711_SU2_LX_SD4:
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
return -EINVAL;
|
||
|
|
}
|
||
|
|
|
||
|
|
switch (pdata->su2_feedback) {
|
||
|
|
case AS3711_SU2_VOLTAGE:
|
||
|
|
max_brightness = min(pdata->su2_max_uA, 31);
|
||
|
|
break;
|
||
|
|
case AS3711_SU2_CURR1:
|
||
|
|
case AS3711_SU2_CURR2:
|
||
|
|
case AS3711_SU2_CURR3:
|
||
|
|
case AS3711_SU2_CURR_AUTO:
|
||
|
|
max_brightness = min(pdata->su2_max_uA / 150, 255);
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
return -EINVAL;
|
||
|
|
}
|
||
|
|
|
||
|
|
ret = as3711_bl_init_su2(supply);
|
||
|
|
if (ret < 0)
|
||
|
|
return ret;
|
||
|
|
|
||
|
|
ret = as3711_bl_register(pdev, max_brightness, su);
|
||
|
|
if (ret < 0)
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
platform_set_drvdata(pdev, supply);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct platform_driver as3711_backlight_driver = {
|
||
|
|
.driver = {
|
||
|
|
.name = "as3711-backlight",
|
||
|
|
},
|
||
|
|
.probe = as3711_backlight_probe,
|
||
|
|
};
|
||
|
|
|
||
|
|
module_platform_driver(as3711_backlight_driver);
|
||
|
|
|
||
|
|
MODULE_DESCRIPTION("Backlight Driver for AS3711 PMICs");
|
||
|
|
MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de");
|
||
|
|
MODULE_LICENSE("GPL");
|
||
|
|
MODULE_ALIAS("platform:as3711-backlight");
|