/*
* tps65217_bl.c
*
* TPS65217 backlight driver
*
* Copyright (C) 2012 Matthias Kaehlcke
* Author: Matthias Kaehlcke <matthias@kaehlcke.net>
*
* This program 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 version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/fb.h>
#include <linux/mfd/tps65217.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
struct tps65217_bl {
struct tps65217 *tps;
struct device *dev;
struct backlight_device *bl;
bool is_enabled;
};
static int tps65217_bl_enable(struct tps65217_bl *tps65217_bl)
{
int rc;
rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
TPS65217_WLEDCTRL1_ISINK_ENABLE,
TPS65217_WLEDCTRL1_ISINK_ENABLE, TPS65217_PROTECT_NONE);
if (rc) {
dev_err(tps65217_bl->dev,
"failed to enable backlight: %d\n", rc);
return rc;
}
tps65217_bl->is_enabled = true;
dev_dbg(tps65217_bl->dev, "backlight enabled\n");
return 0;
}
static int tps65217_bl_disable(struct tps65217_bl *tps65217_bl)
{
int rc;
rc = tps65217_clear_bits(tps65217_bl->tps,
TPS65217_REG_WLEDCTRL1,
TPS65217_WLEDCTRL1_ISINK_ENABLE,
TPS65217_PROTECT_NONE);
if (rc) {
dev_err(tps65217_bl->dev,
"failed to disable backlight: %d\n", rc);
return rc;
}
tps65217_bl->is_enabled = false;
dev_dbg(tps65217_bl->dev, "backlight disabled\n");
return 0;
}
static int tps65217_bl_update_status(struct backlight_device *bl)
{
struct tps65217_bl *tps65217_bl = bl_get_data(bl);
int rc;
int brightness = bl->props.brightness;
if (bl->props.state & BL_CORE_SUSPENDED)
brightness = 0;
if ((bl->props.power != FB_BLANK_UNBLANK) ||
(bl->props.fb_blank != FB_BLANK_UNBLANK))
/* framebuffer in low power mode or blanking active */
brightness = 0;
if (brightness > 0) {
rc = tps65217_reg_write(tps65217_bl->tps,
TPS65217_REG_WLEDCTRL2,
brightness - 1,
TPS65217_PROTECT_NONE);
if (rc) {
dev_err(tps65217_bl->dev,
"failed to set brightness level: %d\n", rc);
return rc;
}
dev_dbg(tps65217_bl->dev, "brightness set to %d\n", brightness);
if (!tps65217_bl->is_enabled)
rc = tps65217_bl_enable(tps65217_bl);
} else {
rc = tps65217_bl_disable(tps65217_bl);
}
return rc;
}
static int tps65217_bl_get_brightness(struct backlight_device *bl)
{
return bl->props.brightness;
}
static const struct backlight_ops tps65217_bl_ops = {
.options = BL_CORE_SUSPENDRESUME,
.update_status = tps65217_bl_update_status,
.get_brightness = tps65217_bl_get_brightness
};
static int tps65217_bl_hw_init(struct tps65217_bl *tps65217_bl,
struct tps65217_bl_pdata *pdata)
{
int rc;
rc = tps65217_bl_disable(tps65217_bl);
if (rc)
return rc;
switch (pdata->isel) {
case TPS65217_BL_ISET1:
/* select ISET_1 current level */
rc = tps65217_clear_bits(tps65217_bl->tps,
TPS65217_REG_WLEDCTRL1,
TPS65217_WLEDCTRL1_ISEL,
TPS65217_PROTECT_NONE);
if (rc) {
dev_err(tps65217_bl->dev,
"failed to select ISET1 current level: %d)\n",
rc);
return rc;
}
dev_dbg(tps65217_bl->dev, "selected ISET1 current level\n");
break;
case TPS65217_BL_ISET2:
/* select ISET2 current level */
rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
TPS65217_WLEDCTRL1_ISEL,
TPS65217_WLEDCTRL1_ISEL, TPS65217_PROTECT_NONE);
if (rc) {
dev_err(tps65217_bl->dev,
"failed to select ISET2 current level: %d\n",
rc);
return rc;
}
dev_dbg(tps65217_bl->dev, "selected ISET2 current level\n");
break;
default:
dev_err(tps65217_bl->dev,
"invalid value for current level: %d\n", pdata->isel);
return -EINVAL;
}
/* set PWM frequency */
rc = tps65217_set_bits(tps65217_bl->tps,
TPS65217_REG_WLEDCTRL1,
TPS65217_WLEDCTRL1_FDIM_MASK,
pdata->fdim,
TPS65217_PROTECT_NONE);
if (rc) {
dev_err(tps65217_bl->dev,
"failed to select PWM dimming frequency: %d\n",
rc);
return rc;
}
return 0;
}
#ifdef CONFIG_OF
static struct tps65217_bl_pdata *
tps65217_bl_parse_dt(struct platform_device *pdev)
{
struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
struct device_node *node = of_node_get(tps->dev->of_node);
struct tps65217_bl_pdata *pdata, *err;
u32 val;
node = of_find_node_by_name(node, "backlight");
if (!node)
return ERR_PTR(-ENODEV);
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata) {
dev_err(&pdev->dev, "failed to allocate platform data\n");
err = ERR_PTR(-ENOMEM);
goto err;
}
pdata->isel = TPS65217_BL_ISET1;
if (!of_property_read_u32(node, "isel", &val)) {
if (val < TPS65217_BL_ISET1 ||
val > TPS65217_BL_ISET2) {
dev_err(&pdev->dev,
"invalid 'isel' value in the device tree\n");
err = ERR_PTR(-EINVAL);
goto err;
}
pdata->isel = val;
}
pdata->fdim = TPS65217_BL_FDIM_200HZ;
if (!of_property_read_u32(node, "fdim", &val)) {
switch (val) {
case 100:
pdata->fdim = TPS65217_BL_FDIM_100HZ;
break;
case 200:
pdata->fdim = TPS65217_BL_FDIM_200HZ;
break;
case 500:
pdata->fdim = TPS65217_BL_FDIM_500HZ;
break;
case 1000:
pdata->fdim = TPS65217_BL_FDIM_1000HZ;
break;
default:
dev_err(&pdev->dev,
"invalid 'fdim' value in the device tree\n");
err = ERR_PTR(-EINVAL);
goto err;
}
}
if (!of_property_read_u32(node, "default-brightness", &val)) {
if (val < 0 ||
val > 100) {
dev_err(&pdev->dev,
"invalid 'default-brightness' value in the device tree\n");
err = ERR_PTR(-EINVAL);
goto err;
}
pdata->dft_brightness = val;
}
of_node_put(node);
return pdata;
err:
of_node_put(node);
return err;
}
#else
static struct tps65217_bl_pdata *
tps65217_bl_parse_dt(struct platform_device *pdev)
{
return NULL;
}
#endif
static int tps65217_bl_probe(struct platform_device *pdev)
{
int rc;
struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
struct tps65217_bl *tps65217_bl;
struct tps65217_bl_pdata *pdata;
struct backlight_properties bl_props;
if (tps->dev->of_node) {
pdata = tps65217_bl_parse_dt(pdev);
if (IS_ERR(pdata))
return PTR_ERR(pdata);
} else {
pdata = dev_get_platdata(&pdev->dev);
if (!pdata) {
dev_err(&pdev->dev, "no platform data provided\n");
return -EINVAL;
}
}
tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl),
GFP_KERNEL);
if (tps65217_bl == NULL) {
dev_err(&pdev->dev, "allocation of struct tps65217_bl failed\n");
return -ENOMEM;
}
tps65217_bl->tps = tps;
tps65217_bl->dev = &pdev->dev;
tps65217_bl->is_enabled = false;
rc = tps65217_bl_hw_init(tps65217_bl, pdata);
if (rc)
return rc;
memset(&bl_props, 0, sizeof(struct backlight_properties));
bl_props.type = BACKLIGHT_RAW;
bl_props.max_brightness = 100;
tps65217_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name,
tps65217_bl->dev, tps65217_bl,
&tps65217_bl_ops, &bl_props);
if (IS_ERR(tps65217_bl->bl)) {
dev_err(tps65217_bl->dev,
"registration of backlight device failed: %d\n", rc);
return PTR_ERR(tps65217_bl->bl);
}
tps65217_bl->bl->props.brightness = pdata->dft_brightness;
backlight_update_status(tps65217_bl->bl);
platform_set_drvdata(pdev, tps65217_bl);
return 0;
}
static struct platform_driver tps65217_bl_driver = {
.probe = tps65217_bl_probe,
.driver = {
.owner = THIS_MODULE,
.name = "tps65217-bl",
},
};
module_platform_driver(tps65217_bl_driver);
MODULE_DESCRIPTION("TPS65217 Backlight driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");
