linux/drivers/video/backlight/l4f00242t03.c
Axel Lin beb0a43f39 backlight: l4f00242t03: fix error handling in l4f00242t03_probe
Error handling fixes:
1. In the case of kzalloc failure, simple return -ENOMEM instead of goto
   err. ( priv is NULL in this case )
2. In the case of gpio_request fail for reset_gpio and data_enable_gpio,
   properly release resources by goto err and err2 respectively.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Alberto Panizzo <maramaopercheseimorto@gmail.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2010-05-26 17:34:35 +01:00

258 lines
5.6 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.
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/delay.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_on:1;
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 = dev_get_drvdata(&spi->dev);
const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
dev_dbg(&spi->dev, "initializing LCD\n");
if (priv->io_reg) {
regulator_set_voltage(priv->io_reg, 1800000, 1800000);
regulator_enable(priv->io_reg);
}
if (priv->core_reg) {
regulator_set_voltage(priv->core_reg, 2800000, 2800000);
regulator_enable(priv->core_reg);
}
gpio_set_value(pdata->data_enable_gpio, 1);
msleep(60);
spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
}
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) {
if (priv->lcd_on)
return 0;
dev_dbg(&spi->dev, "turning on LCD\n");
spi_write(spi, (const u8 *)&slpout, sizeof(u16));
msleep(60);
spi_write(spi, (const u8 *)&dison, sizeof(u16));
priv->lcd_on = 1;
} else {
if (!priv->lcd_on)
return 0;
dev_dbg(&spi->dev, "turning off LCD\n");
spi_write(spi, (const u8 *)&disoff, sizeof(u16));
msleep(60);
spi_write(spi, (const u8 *)&slpin, sizeof(u16));
priv->lcd_on = 0;
}
return 0;
}
static struct lcd_ops l4f_ops = {
.set_power = l4f00242t03_lcd_power_set,
.get_power = NULL,
};
static int __devinit 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 = kzalloc(sizeof(struct l4f00242t03_priv), GFP_KERNEL);
if (priv == NULL) {
dev_err(&spi->dev, "No memory for this device.\n");
return -ENOMEM;
}
dev_set_drvdata(&spi->dev, priv);
spi->bits_per_word = 9;
spi_setup(spi);
priv->spi = spi;
ret = gpio_request(pdata->reset_gpio, "lcd l4f00242t03 reset");
if (ret) {
dev_err(&spi->dev,
"Unable to get the lcd l4f00242t03 reset gpio.\n");
goto err;
}
ret = gpio_direction_output(pdata->reset_gpio, 1);
if (ret)
goto err2;
ret = gpio_request(pdata->data_enable_gpio,
"lcd l4f00242t03 data enable");
if (ret) {
dev_err(&spi->dev,
"Unable to get the lcd l4f00242t03 data en gpio.\n");
goto err2;
}
ret = gpio_direction_output(pdata->data_enable_gpio, 0);
if (ret)
goto err3;
if (pdata->io_supply) {
priv->io_reg = regulator_get(NULL, pdata->io_supply);
if (IS_ERR(priv->io_reg)) {
pr_err("%s: Unable to get the IO regulator\n",
__func__);
goto err3;
}
}
if (pdata->core_supply) {
priv->core_reg = regulator_get(NULL, pdata->core_supply);
if (IS_ERR(priv->core_reg)) {
pr_err("%s: Unable to get the core regulator\n",
__func__);
goto err4;
}
}
priv->ld = lcd_device_register("l4f00242t03",
&spi->dev, priv, &l4f_ops);
if (IS_ERR(priv->ld)) {
ret = PTR_ERR(priv->ld);
goto err5;
}
/* Init the LCD */
l4f00242t03_reset(pdata->reset_gpio);
l4f00242t03_lcd_init(spi);
l4f00242t03_lcd_power_set(priv->ld, 1);
dev_info(&spi->dev, "Epson l4f00242t03 lcd probed.\n");
return 0;
err5:
if (priv->core_reg)
regulator_put(priv->core_reg);
err4:
if (priv->io_reg)
regulator_put(priv->io_reg);
err3:
gpio_free(pdata->data_enable_gpio);
err2:
gpio_free(pdata->reset_gpio);
err:
kfree(priv);
return ret;
}
static int __devexit l4f00242t03_remove(struct spi_device *spi)
{
struct l4f00242t03_priv *priv = dev_get_drvdata(&spi->dev);
struct l4f00242t03_pdata *pdata = priv->spi->dev.platform_data;
l4f00242t03_lcd_power_set(priv->ld, 0);
lcd_device_unregister(priv->ld);
gpio_free(pdata->data_enable_gpio);
gpio_free(pdata->reset_gpio);
if (priv->io_reg)
regulator_put(priv->io_reg);
if (priv->core_reg)
regulator_put(priv->core_reg);
kfree(priv);
return 0;
}
static struct spi_driver l4f00242t03_driver = {
.driver = {
.name = "l4f00242t03",
.owner = THIS_MODULE,
},
.probe = l4f00242t03_probe,
.remove = __devexit_p(l4f00242t03_remove),
};
static __init int l4f00242t03_init(void)
{
return spi_register_driver(&l4f00242t03_driver);
}
static __exit void l4f00242t03_exit(void)
{
spi_unregister_driver(&l4f00242t03_driver);
}
module_init(l4f00242t03_init);
module_exit(l4f00242t03_exit);
MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
MODULE_DESCRIPTION("EPSON L4F00242T03 LCD");
MODULE_LICENSE("GPL v2");