Re: [PATCH 06/15] video: lcd: add LoCoMo LCD driver

[Jingoo Han <jg1.han@samsung.com>]

On Tuesday, October 28, 2014 9:02 AM, Dmitry Eremin-Solenikov wrote:
> 
> LoCoMo has some special handling for TFT screens attached to Collie and
> Poodle. Implement that as a separate driver.
> 
> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> ---
>  drivers/video/backlight/Kconfig      |   8 ++
>  drivers/video/backlight/Makefile     |   1 +
>  drivers/video/backlight/locomo_lcd.c | 224 +++++++++++++++++++++++++++++++++++
>  3 files changed, 233 insertions(+)
>  create mode 100644 drivers/video/backlight/locomo_lcd.c
> 
> diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
> index 03b77b33..bc5c671 100644
> --- a/drivers/video/backlight/Kconfig
> +++ b/drivers/video/backlight/Kconfig
> @@ -48,6 +48,14 @@ config LCD_LMS283GF05
>  	  SPI driver for Samsung LMS283GF05. This provides basic support
>  	  for powering the LCD up/down through a sysfs interface.
> 
> +config LCD_LOCOMO
> +	tristate "Sharp LOCOMO LCD Driver"
> +	depends on MFD_LOCOMO
> +	default y
> +	help
> +	  If you have a Sharp Zaurus SL-5500 (Collie) or SL-5600 (Poodle) say y to
> +	  enable the LCD driver.
> +
>  config LCD_LTV350QV
>  	tristate "Samsung LTV350QV LCD Panel"
>  	depends on SPI_MASTER
> diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
> index 2a61b7e..b2580e7 100644
> --- a/drivers/video/backlight/Makefile
> +++ b/drivers/video/backlight/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_LCD_ILI922X)		+= ili922x.o
>  obj-$(CONFIG_LCD_ILI9320)		+= ili9320.o
>  obj-$(CONFIG_LCD_L4F00242T03)		+= l4f00242t03.o
>  obj-$(CONFIG_LCD_LD9040)		+= ld9040.o
> +obj-$(CONFIG_LCD_LOCOMO)		+= locomo_lcd.o

Please insert this alphabetically for the readability.

>  obj-$(CONFIG_LCD_LMS283GF05)		+= lms283gf05.o
>  obj-$(CONFIG_LCD_LMS501KF03)		+= lms501kf03.o
>  obj-$(CONFIG_LCD_LTV350QV)		+= ltv350qv.o
> diff --git a/drivers/video/backlight/locomo_lcd.c b/drivers/video/backlight/locomo_lcd.c
> new file mode 100644
> index 0000000..245efb8
> --- /dev/null
> +++ b/drivers/video/backlight/locomo_lcd.c
> @@ -0,0 +1,224 @@
> +/*
> + * Backlight control code for Sharp Zaurus SL-5500
> + *
> + * Copyright 2005 John Lenz <lenz@cs.wisc.edu>
> + * Maintainer: Pavel Machek <pavel@ucw.cz> (unless John wants to :-)
> + * GPL v2
> + *
> + * This driver assumes single CPU. That's okay, because collie is
> + * slightly old hardware, and no one is going to retrofit second CPU to
> + * old PDA.
> + */
> +
> +/* LCD power functions */
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/platform_device.h>
> +#include <linux/fb.h>
> +#include <linux/backlight.h>
> +#include <linux/err.h>
> +#include <linux/gpio.h>
> +#include <linux/delay.h>
> +#include <linux/lcd.h>
> +#include <linux/mfd/locomo.h>

Please, re-order these headers alphabetically.
It enhances the readability.

> +
> +static struct platform_device *locomolcd_dev;
> +static struct locomo_lcd_platform_data lcd_data;
> +static bool locomolcd_is_on;
> +static bool locomolcd_is_suspended;
> +static void __iomem *locomolcd_regs;
> +static struct lcd_device *lcd_dev;
> +
> +static struct gpio locomo_gpios[] = {
> +	{ 0, GPIOF_OUT_INIT_LOW, "LCD VSHA on" },
> +	{ 0, GPIOF_OUT_INIT_LOW, "LCD VSHD on" },
> +	{ 0, GPIOF_OUT_INIT_LOW, "LCD Vee on" },
> +	{ 0, GPIOF_OUT_INIT_LOW, "LCD MOD" },
> +};
> +
> +static void locomolcd_on(void)
> +{
> +	gpio_set_value(lcd_data.gpio_lcd_vsha_on, 1);
> +	mdelay(2);
> +
> +	gpio_set_value(lcd_data.gpio_lcd_vshd_on, 1);
> +	mdelay(2);
> +
> +	locomo_m62332_senddata(locomolcd_dev->dev.parent, lcd_data.comadj, 0);
> +	mdelay(5);
> +
> +	gpio_set_value(lcd_data.gpio_lcd_vee_on, 1);
> +	mdelay(10);

How about changing mdelay() to usleep_range()?

> +
> +	/* TFTCRST | CPSOUT=0 | CPSEN */
> +	writew(0x01, locomolcd_regs + LOCOMO_TC);
> +
> +	/* Set CPSD */
> +	writew(6, locomolcd_regs + LOCOMO_CPSD);
> +
> +	/* TFTCRST | CPSOUT=0 | CPSEN */
> +	writew((0x04 | 0x01), locomolcd_regs + LOCOMO_TC);
> +	mdelay(10);
> +
> +	gpio_set_value(lcd_data.gpio_lcd_mod, 1);
> +}
> +
> +static void locomolcd_off(void)
> +{
> +	/* TFTCRST=1 | CPSOUT=1 | CPSEN = 0 */
> +	writew(0x06, locomolcd_regs + LOCOMO_TC);
> +	mdelay(1);
> +
> +	gpio_set_value(lcd_data.gpio_lcd_vsha_on, 0);
> +	mdelay(110);
> +
> +	gpio_set_value(lcd_data.gpio_lcd_vee_on, 0);
> +	mdelay(700);
> +
> +	locomo_m62332_senddata(locomolcd_dev->dev.parent, 0, 0);
> +	mdelay(5);

How about changing mdelay() to usleep_range() or msleep()?

> +
> +	/* TFTCRST=0 | CPSOUT=0 | CPSEN = 0 */
> +	writew(0, locomolcd_regs + LOCOMO_TC);
> +	gpio_set_value(lcd_data.gpio_lcd_mod, 0);
> +	gpio_set_value(lcd_data.gpio_lcd_vshd_on, 0);
> +}
> +
> +int locomo_lcd_set_power(struct lcd_device *lcd, int power)
> +{
> +	dev_dbg(&lcd->dev, "LCD power %d (is %d)\n", power, locomolcd_is_on);
> +	if (power == 0 && !locomolcd_is_on) {
> +		locomolcd_is_on = 1;
> +		locomolcd_on();
> +	}
> +	if (power != 0 && locomolcd_is_on) {
> +		locomolcd_is_on = 0;
> +		locomolcd_off();
> +	}
> +	return 0;
> +}
> +
> +static int locomo_lcd_get_power(struct lcd_device *lcd)
> +{
> +	return !locomolcd_is_on;
> +}
> +
> +static struct lcd_ops locomo_lcd_ops = {
> +	.set_power = locomo_lcd_set_power,
> +	.get_power = locomo_lcd_get_power,
> +};
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int locomolcd_suspend(struct device *dev)
> +{
> +	locomolcd_is_suspended = true;
> +	locomolcd_off();
> +
> +	return 0;
> +}
> +
> +static int locomolcd_resume(struct device *dev)
> +{
> +	locomolcd_is_suspended = false;
> +
> +	if (locomolcd_is_on)
> +		locomolcd_on();
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(locomolcd_pm, locomolcd_suspend, locomolcd_resume);
> +#define LOCOMOLCD_PM	(&locomolcd_pm)
> +#else
> +#define LOCOMOLCD_PM	NULL
> +#endif
> +
> +static int locomolcd_probe(struct platform_device *dev)
> +{
> +	unsigned long flags;
> +	struct resource *res;
> +	struct locomo_lcd_platform_data *pdata;
> +	int rc;
> +
> +	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
> +	if (!res)
> +		return -EINVAL;
> +	locomolcd_regs = devm_ioremap_resource(&dev->dev, res);
> +	if (!locomolcd_regs)
> +		return -EINVAL;

Please change it as below.

	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	locomolcd_regs = devm_ioremap_resource(&dev->dev, res);
	if (IS_ERR(locomolcd_regs))
		 return PTR_ERR(locomolcd_regs);
> +
> +	pdata = dev_get_platdata(&dev->dev);
> +	if (!pdata)
> +		return -EINVAL;
> +
> +	lcd_data = *pdata;
> +
> +	locomo_gpios[0].gpio = lcd_data.gpio_lcd_vsha_on;
> +	locomo_gpios[1].gpio = lcd_data.gpio_lcd_vshd_on;
> +	locomo_gpios[2].gpio = lcd_data.gpio_lcd_vee_on;
> +	locomo_gpios[3].gpio = lcd_data.gpio_lcd_mod;
> +	dev_info(&dev->dev, "GPIOs: %d %d %d %d\n",
> +			locomo_gpios[0].gpio,
> +			locomo_gpios[1].gpio,
> +			locomo_gpios[2].gpio,
> +			locomo_gpios[3].gpio);
> +
> +	rc = gpio_request_array(locomo_gpios, ARRAY_SIZE(locomo_gpios));
> +	if (rc)
> +		return rc;
> +
> +	local_irq_save(flags);
> +	locomolcd_dev = dev;
> +
> +	locomolcd_is_on = 1;
> +	if (locomolcd_is_on)
> +		locomolcd_on();
> +
> +	local_irq_restore(flags);
> +
> +	lcd_dev = lcd_device_register("locomo", &dev->dev, NULL,

Please use devm_lcd_device_register().

> +			&locomo_lcd_ops);
> +
> +	return 0;
> +}
> +
> +static int locomolcd_remove(struct platform_device *dev)
> +{
> +	unsigned long flags;
> +
> +	lcd_device_unregister(lcd_dev);

If devm_lcd_device_register() is used in probe(),
there is no need to call lcd_device_unregister() in remove().

> +
> +	local_irq_save(flags);
> +
> +	locomolcd_off();
> +	locomolcd_dev = NULL;
> +
> +	local_irq_restore(flags);
> +
> +	gpio_free_array(locomo_gpios, ARRAY_SIZE(locomo_gpios));
> +
> +	return 0;
> +}
> +
> +static void locomolcd_shutdown(struct platform_device *dev)
> +{
> +	locomolcd_off();
> +}
> +
> +static struct platform_driver locomolcd_driver = {
> +	.driver = {
> +		.name	= "locomo-lcd",
> +		.owner	= THIS_MODULE,
> +		.pm	= LOCOMOLCD_PM,
> +	},
> +	.probe	= locomolcd_probe,
> +	.remove	= locomolcd_remove,
> +	.shutdown = locomolcd_shutdown,
> +};
> +
> +module_platform_driver(locomolcd_driver);
> +
> +MODULE_AUTHOR("John Lenz <lenz@cs.wisc.edu>, Pavel Machek <pavel@ucw.cz>");


Please split these authors to lines as below.

MODULE_AUTHOR("John Lenz <lenz@cs.wisc.edu>");
MODULE_AUTHOR("Pavel Machek <pavel@ucw.cz>");

> +MODULE_DESCRIPTION("Collie LCD driver");

What does mean 'Collie'? 'Locomo' looks better.

> +MODULE_LICENSE("GPL");

How about using "GPL v2"?

Thank you.

Best regards,
Jingoo Han

> +MODULE_ALIAS("platform:locomo-lcd");
> --
> 2.1.1