linux/drivers/video/backlight/l4f00242t03.c
Jingoo Han ef73e632fe drivers/video/backlight/l4f00242t03.c: check return value of regulator_enable()
regulator_enable() is marked as as __must_check.  Therefore the return
value of regulator_enable() should be checked.  Also, this patch checks
return value of regulator_set_voltage().

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 18:28:15 -07:00

276 lines
6.9 KiB
C

/*
* l4f00242t03.c -- support for Epson L4F00242T03 LCD
*
* Copyright 2007-2009 Freescale Semiconductor, Inc. All Rights Reserved.
*
* Copyright (c) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
* Inspired by Marek Vasut work in l4f00242t03.c
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/lcd.h>
#include <linux/slab.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
#include <linux/spi/l4f00242t03.h>
struct l4f00242t03_priv {
struct spi_device *spi;
struct lcd_device *ld;
int lcd_state;
struct regulator *io_reg;
struct regulator *core_reg;
};
static void l4f00242t03_reset(unsigned int gpio)
{
pr_debug("l4f00242t03_reset.\n");
gpio_set_value(gpio, 1);
mdelay(100);
gpio_set_value(gpio, 0);
mdelay(10); /* tRES >= 100us */
gpio_set_value(gpio, 1);
mdelay(20);
}
#define param(x) ((x) | 0x100)
static void l4f00242t03_lcd_init(struct spi_device *spi)
{
struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
int ret;
dev_dbg(&spi->dev, "initializing LCD\n");
ret = regulator_set_voltage(priv->io_reg, 1800000, 1800000);
if (ret) {
dev_err(&spi->dev, "failed to set the IO regulator voltage.\n");
return;
}
ret = regulator_enable(priv->io_reg);
if (ret) {
dev_err(&spi->dev, "failed to enable the IO regulator.\n");
return;
}
ret = regulator_set_voltage(priv->core_reg, 2800000, 2800000);
if (ret) {
dev_err(&spi->dev, "failed to set the core regulator voltage.\n");
regulator_disable(priv->io_reg);
return;
}
ret = regulator_enable(priv->core_reg);
if (ret) {
dev_err(&spi->dev, "failed to enable the core regulator.\n");
regulator_disable(priv->io_reg);
return;
}
l4f00242t03_reset(pdata->reset_gpio);
gpio_set_value(pdata->data_enable_gpio, 1);
msleep(60);
spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
}
static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
{
struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
dev_dbg(&spi->dev, "Powering down LCD\n");
gpio_set_value(pdata->data_enable_gpio, 0);
regulator_disable(priv->io_reg);
regulator_disable(priv->core_reg);
}
static int l4f00242t03_lcd_power_get(struct lcd_device *ld)
{
struct l4f00242t03_priv *priv = lcd_get_data(ld);
return priv->lcd_state;
}
static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
{
struct l4f00242t03_priv *priv = lcd_get_data(ld);
struct spi_device *spi = priv->spi;
const u16 slpout = 0x11;
const u16 dison = 0x29;
const u16 slpin = 0x10;
const u16 disoff = 0x28;
if (power <= FB_BLANK_NORMAL) {
if (priv->lcd_state <= FB_BLANK_NORMAL) {
/* Do nothing, the LCD is running */
} else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
dev_dbg(&spi->dev, "Resuming LCD\n");
spi_write(spi, (const u8 *)&slpout, sizeof(u16));
msleep(60);
spi_write(spi, (const u8 *)&dison, sizeof(u16));
} else {
/* priv->lcd_state == FB_BLANK_POWERDOWN */
l4f00242t03_lcd_init(spi);
priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
l4f00242t03_lcd_power_set(priv->ld, power);
}
} else if (power < FB_BLANK_POWERDOWN) {
if (priv->lcd_state <= FB_BLANK_NORMAL) {
/* Send the display in standby */
dev_dbg(&spi->dev, "Standby the LCD\n");
spi_write(spi, (const u8 *)&disoff, sizeof(u16));
msleep(60);
spi_write(spi, (const u8 *)&slpin, sizeof(u16));
} else if (priv->lcd_state < FB_BLANK_POWERDOWN) {
/* Do nothing, the LCD is already in standby */
} else {
/* priv->lcd_state == FB_BLANK_POWERDOWN */
l4f00242t03_lcd_init(spi);
priv->lcd_state = FB_BLANK_UNBLANK;
l4f00242t03_lcd_power_set(ld, power);
}
} else {
/* power == FB_BLANK_POWERDOWN */
if (priv->lcd_state != FB_BLANK_POWERDOWN) {
/* Clear the screen before shutting down */
spi_write(spi, (const u8 *)&disoff, sizeof(u16));
msleep(60);
l4f00242t03_lcd_powerdown(spi);
}
}
priv->lcd_state = power;
return 0;
}
static struct lcd_ops l4f_ops = {
.set_power = l4f00242t03_lcd_power_set,
.get_power = l4f00242t03_lcd_power_get,
};
static int l4f00242t03_probe(struct spi_device *spi)
{
struct l4f00242t03_priv *priv;
struct l4f00242t03_pdata *pdata = spi->dev.platform_data;
int ret;
if (pdata == NULL) {
dev_err(&spi->dev, "Uninitialized platform data.\n");
return -EINVAL;
}
priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
GFP_KERNEL);
if (priv == NULL) {
dev_err(&spi->dev, "No memory for this device.\n");
return -ENOMEM;
}
spi_set_drvdata(spi, priv);
spi->bits_per_word = 9;
spi_setup(spi);
priv->spi = spi;
ret = devm_gpio_request_one(&spi->dev, pdata->reset_gpio,
GPIOF_OUT_INIT_HIGH, "lcd l4f00242t03 reset");
if (ret) {
dev_err(&spi->dev,
"Unable to get the lcd l4f00242t03 reset gpio.\n");
return ret;
}
ret = devm_gpio_request_one(&spi->dev, pdata->data_enable_gpio,
GPIOF_OUT_INIT_LOW, "lcd l4f00242t03 data enable");
if (ret) {
dev_err(&spi->dev,
"Unable to get the lcd l4f00242t03 data en gpio.\n");
return ret;
}
priv->io_reg = devm_regulator_get(&spi->dev, "vdd");
if (IS_ERR(priv->io_reg)) {
dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
__func__);
return PTR_ERR(priv->io_reg);
}
priv->core_reg = devm_regulator_get(&spi->dev, "vcore");
if (IS_ERR(priv->core_reg)) {
dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
__func__);
return PTR_ERR(priv->core_reg);
}
priv->ld = lcd_device_register("l4f00242t03",
&spi->dev, priv, &l4f_ops);
if (IS_ERR(priv->ld))
return PTR_ERR(priv->ld);
/* Init the LCD */
l4f00242t03_lcd_init(spi);
priv->lcd_state = FB_BLANK_VSYNC_SUSPEND;
l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK);
dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
return 0;
}
static int l4f00242t03_remove(struct spi_device *spi)
{
struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
lcd_device_unregister(priv->ld);
spi_set_drvdata(spi, NULL);
return 0;
}
static void l4f00242t03_shutdown(struct spi_device *spi)
{
struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
if (priv)
l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_POWERDOWN);
}
static struct spi_driver l4f00242t03_driver = {
.driver = {
.name = "l4f00242t03",
.owner = THIS_MODULE,
},
.probe = l4f00242t03_probe,
.remove = l4f00242t03_remove,
.shutdown = l4f00242t03_shutdown,
};
module_spi_driver(l4f00242t03_driver);
MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
MODULE_LICENSE("GPL v2");