diff mbox

[v5,07/17] video: lcd: add LoCoMo LCD driver

Message ID 1433797008-6246-8-git-send-email-dbaryshkov@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dmitry Baryshkov June 8, 2015, 8:56 p.m. UTC
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>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
---
 drivers/video/backlight/Kconfig      |  10 ++
 drivers/video/backlight/Makefile     |   1 +
 drivers/video/backlight/locomo_lcd.c | 285 +++++++++++++++++++++++++++++++++++
 3 files changed, 296 insertions(+)
 create mode 100644 drivers/video/backlight/locomo_lcd.c

Comments

Russell King - ARM Linux June 14, 2015, 3:18 p.m. UTC | #1
On Mon, Jun 08, 2015 at 11:56:38PM +0300, Dmitry Eremin-Solenikov wrote:
> +int locomo_lcd_set_power(struct lcd_device *ldev, int power)
> +{
> +	struct locomo_lcd *lcd = lcd_get_data(ldev);
> +
> +	dev_dbg(&ldev->dev, "LCD power %d (is %d)\n", power, lcd->power);
> +
> +	if (!power && lcd->power)
> +		locomo_lcd_on(lcd);
> +
> +	if (power && !lcd->power)
> +		locomo_lcd_off(lcd);

Is this correct?  You want to turn the LCD _off_ if power is non-zero, but
turn it _on_ if power is _zero_ ?

Just wondering if this would be clearer:

	if (!power != !lcd->power) {
		/* Power state is different */
		if (!power)
			locomo_lcd_on(lcd);
		else
			locomo_lcd_off(lcd);

		lcd->power = power;
	}

At least less prone to getting the power state wrong...

> +static int locomo_lcd_remove(struct platform_device *dev)
> +{
> +	struct lcd_device *ldev = platform_get_drvdata(dev);
> +	struct locomo_lcd *lcd = lcd_get_data(ldev);
> +
> +	locomo_lcd_off(lcd);

You're careful above not to turn the LCD off if it's already off, but here
that doesn't matter?  What if the LCD is already off?  Does this need
protection against double-off?

> +
> +	locomo_lcd_disable_adsync(lcd);
> +
> +	iio_channel_release(lcd->comadj);
> +
> +	return 0;
> +}
> +
> +static void locomo_lcd_shutdown(struct platform_device *dev)
> +{
> +	struct lcd_device *ldev = platform_get_drvdata(dev);
> +	struct locomo_lcd *lcd = lcd_get_data(ldev);
> +
> +	locomo_lcd_off(lcd);

Ditto.
Dmitry Baryshkov June 14, 2015, 4:28 p.m. UTC | #2
2015-06-14 18:18 GMT+03:00 Russell King - ARM Linux <linux@arm.linux.org.uk>:
> On Mon, Jun 08, 2015 at 11:56:38PM +0300, Dmitry Eremin-Solenikov wrote:
>> +int locomo_lcd_set_power(struct lcd_device *ldev, int power)
>> +{
>> +     struct locomo_lcd *lcd = lcd_get_data(ldev);
>> +
>> +     dev_dbg(&ldev->dev, "LCD power %d (is %d)\n", power, lcd->power);
>> +
>> +     if (!power && lcd->power)
>> +             locomo_lcd_on(lcd);
>> +
>> +     if (power && !lcd->power)
>> +             locomo_lcd_off(lcd);
>
> Is this correct?  You want to turn the LCD _off_ if power is non-zero, but
> turn it _on_ if power is _zero_ ?

Yes, this is a crazy part of fb/backlight/LCD, where power is a FB_BLANK_*
value, and FB_BLANK_UNBLANK is equal to 0.
Russell King - ARM Linux June 14, 2015, 5:16 p.m. UTC | #3
On Sun, Jun 14, 2015 at 07:28:50PM +0300, Dmitry Eremin-Solenikov wrote:
> 2015-06-14 18:18 GMT+03:00 Russell King - ARM Linux <linux@arm.linux.org.uk>:
> > On Mon, Jun 08, 2015 at 11:56:38PM +0300, Dmitry Eremin-Solenikov wrote:
> >> +int locomo_lcd_set_power(struct lcd_device *ldev, int power)
> >> +{
> >> +     struct locomo_lcd *lcd = lcd_get_data(ldev);
> >> +
> >> +     dev_dbg(&ldev->dev, "LCD power %d (is %d)\n", power, lcd->power);
> >> +
> >> +     if (!power && lcd->power)
> >> +             locomo_lcd_on(lcd);
> >> +
> >> +     if (power && !lcd->power)
> >> +             locomo_lcd_off(lcd);
> >
> > Is this correct?  You want to turn the LCD _off_ if power is non-zero, but
> > turn it _on_ if power is _zero_ ?
> 
> Yes, this is a crazy part of fb/backlight/LCD, where power is a FB_BLANK_*
> value, and FB_BLANK_UNBLANK is equal to 0.

In which case, the code is probably wrong anyway.  This would make it much
clearer:

	bool power_on = power == FB_BLANK_UNBLANK;

	if (power_on != lcd->power_is_on) {
		if (power_on)
			locomo_lcd_on(lcd);
		else
			locomo_lcd_off(lcd);

		lcd->power_is_on = power_on;
	}

with lcd->power_is_on also being a bool.  The above is almost English...

	if the power state is different from last time, then
		if we want power on
			call locomo_lcd_on
		otherwise
			call locomo_lcd_off
		remember power state
diff mbox

Patch

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 6c093e2..b2f995c 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -48,6 +48,16 @@  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
+	select IIO
+	help
+	  If you have a Sharp Zaurus SL-5500 (Collie) or SL-5600 (Poodle) say y to
+	  enable the LCD driver.  The panel starts up in power
+	  off state, so you need this driver in order to see any
+	  output.
+
 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 2de73d2..686cf1a 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -11,6 +11,7 @@  obj-$(CONFIG_LCD_L4F00242T03)		+= l4f00242t03.o
 obj-$(CONFIG_LCD_LD9040)		+= ld9040.o
 obj-$(CONFIG_LCD_LMS283GF05)		+= lms283gf05.o
 obj-$(CONFIG_LCD_LMS501KF03)		+= lms501kf03.o
+obj-$(CONFIG_LCD_LOCOMO)		+= locomo_lcd.o
 obj-$(CONFIG_LCD_LTV350QV)		+= ltv350qv.o
 obj-$(CONFIG_LCD_PLATFORM)		+= platform_lcd.o
 obj-$(CONFIG_LCD_S6E63M0)		+= s6e63m0.o
diff --git a/drivers/video/backlight/locomo_lcd.c b/drivers/video/backlight/locomo_lcd.c
new file mode 100644
index 0000000..dc316cb
--- /dev/null
+++ b/drivers/video/backlight/locomo_lcd.c
@@ -0,0 +1,285 @@ 
+/*
+ * 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.
+ */
+
+#include <linux/delay.h>
+#include <linux/fb.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/consumer.h>
+#include <linux/lcd.h>
+#include <linux/mfd/locomo.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+struct locomo_lcd {
+	struct regmap *regmap;
+	struct platform_device *dev;
+	struct locomo_lcd_platform_data *data;
+	int power;
+	struct iio_channel *comadj;
+	struct gpio_desc *vsha, *vshd, *vee, *mod;
+};
+
+static void locomo_lcd_on(struct locomo_lcd *lcd)
+{
+	gpiod_set_value(lcd->vsha, 1);
+	usleep_range(2000, 3000);
+
+	gpiod_set_value(lcd->vshd, 1);
+	usleep_range(2000, 3000);
+
+	iio_write_channel_raw(lcd->comadj, lcd->data->comadj);
+	usleep_range(5000, 6000);
+
+	gpiod_set_value(lcd->vee, 1);
+	usleep_range(10000, 11000);
+
+	/* TFTCRST | CPSOUT=0 | CPSEN */
+	regmap_write(lcd->regmap, LOCOMO_TC, 0x01);
+
+	/* Set CPSD */
+	regmap_write(lcd->regmap, LOCOMO_CPSD, 6);
+
+	/* TFTCRST | CPSOUT=0 | CPSEN */
+	regmap_write(lcd->regmap, LOCOMO_TC, 0x04 | 0x01);
+	usleep_range(10000, 11000);
+
+	gpiod_set_value(lcd->mod, 1);
+}
+
+static void locomo_lcd_off(struct locomo_lcd *lcd)
+{
+	/* TFTCRST=1 | CPSOUT=1 | CPSEN = 0 */
+	regmap_write(lcd->regmap, LOCOMO_TC, 0x06);
+	usleep_range(1000, 2000);
+
+	gpiod_set_value(lcd->vsha, 0);
+	msleep(110);
+
+	gpiod_set_value(lcd->vee, 0);
+	msleep(700);
+
+	iio_write_channel_raw(lcd->comadj, 0);
+	usleep_range(5000, 6000);
+
+	/* TFTCRST=0 | CPSOUT=0 | CPSEN = 0 */
+	regmap_write(lcd->regmap, LOCOMO_TC, 0);
+	gpiod_set_value(lcd->mod, 0);
+	gpiod_set_value(lcd->vshd, 0);
+}
+
+static void locomo_lcd_program_adsync(struct locomo_lcd *lcd)
+{
+	regmap_write(lcd->regmap, LOCOMO_ASD,
+			6 + 8 + 320 + 30 - 10);
+	regmap_update_bits(lcd->regmap, LOCOMO_ASD,
+		0x8000,
+		0x8000);
+
+	regmap_write(lcd->regmap, LOCOMO_HSD,
+			6 + 8 + 320 + 30 - 10 - 128 + 4);
+	regmap_update_bits(lcd->regmap, LOCOMO_HSD,
+		0x8000,
+		0x8000);
+
+	regmap_write(lcd->regmap, LOCOMO_HSC, 128 / 8);
+
+	/* XON */
+	regmap_write(lcd->regmap, LOCOMO_TADC, 0x80);
+	usleep_range(1000, 1100);
+
+	/* CLK9MEN */
+	regmap_update_bits(lcd->regmap, LOCOMO_TADC,
+		0x10,
+		0x10);
+	usleep_range(100, 200);
+}
+
+static void locomo_lcd_disable_adsync(struct locomo_lcd *lcd)
+{
+	/* ADSTART */
+	regmap_write(lcd->regmap, LOCOMO_ASD, 0x00);
+
+	/* 18MHz clock off*/
+	regmap_write(lcd->regmap, LOCOMO_TADC, 0x00);
+}
+
+int locomo_lcd_set_power(struct lcd_device *ldev, int power)
+{
+	struct locomo_lcd *lcd = lcd_get_data(ldev);
+
+	dev_dbg(&ldev->dev, "LCD power %d (is %d)\n", power, lcd->power);
+
+	if (!power && lcd->power)
+		locomo_lcd_on(lcd);
+
+	if (power && !lcd->power)
+		locomo_lcd_off(lcd);
+
+	lcd->power = power;
+
+	return 0;
+}
+
+static int locomo_lcd_get_power(struct lcd_device *ldev)
+{
+	struct locomo_lcd *lcd = lcd_get_data(ldev);
+
+	return lcd->power;
+}
+
+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 locomo_lcd_suspend(struct device *dev)
+{
+	struct lcd_device *ldev = dev_get_drvdata(dev);
+	struct locomo_lcd *lcd = lcd_get_data(ldev);
+
+	locomo_lcd_off(lcd);
+
+	locomo_lcd_disable_adsync(lcd);
+
+	return 0;
+}
+
+static int locomo_lcd_resume(struct device *dev)
+{
+	struct lcd_device *ldev = dev_get_drvdata(dev);
+	struct locomo_lcd *lcd = lcd_get_data(ldev);
+
+	locomo_lcd_program_adsync(lcd);
+
+	if (!lcd->power)
+		locomo_lcd_on(lcd);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(locomo_lcd_pm, locomo_lcd_suspend, locomo_lcd_resume);
+#define LOCOMOLCD_PM	(&locomo_lcd_pm)
+#else
+#define LOCOMOLCD_PM	NULL
+#endif
+
+static int locomo_lcd_probe(struct platform_device *dev)
+{
+	struct lcd_device *lcd_dev;
+	struct locomo_lcd *lcd;
+	int rc;
+
+	lcd = devm_kmalloc(&dev->dev, sizeof(struct locomo_lcd), GFP_KERNEL);
+	if (!lcd)
+		return -ENOMEM;
+
+	lcd->dev = dev;
+	lcd->power = FB_BLANK_NORMAL;
+
+	lcd->regmap = dev_get_regmap(dev->dev.parent, NULL);
+	if (!lcd->regmap)
+		return -ENODEV;
+
+	lcd->data = dev_get_platdata(&dev->dev);
+	if (!lcd->data)
+		return -EINVAL;
+
+	lcd->vsha = devm_gpiod_get(&dev->dev, "VSHA", GPIOD_OUT_LOW);
+	if (IS_ERR(lcd->vsha))
+		return PTR_ERR(lcd->vsha);
+
+	lcd->vshd = devm_gpiod_get(&dev->dev, "VSHD", GPIOD_OUT_LOW);
+	if (IS_ERR(lcd->vshd))
+		return PTR_ERR(lcd->vshd);
+
+	lcd->vee = devm_gpiod_get(&dev->dev, "Vee", GPIOD_OUT_LOW);
+	if (IS_ERR(lcd->vee))
+		return PTR_ERR(lcd->vee);
+
+	lcd->mod = devm_gpiod_get(&dev->dev, "MOD", GPIOD_OUT_LOW);
+	if (IS_ERR(lcd->mod))
+		return PTR_ERR(lcd->mod);
+
+	lcd->comadj = iio_channel_get(&dev->dev, "comadj");
+	if (IS_ERR(lcd->comadj)) {
+		rc = PTR_ERR(lcd->comadj);
+		if (rc == -ENODEV)
+			rc = -EPROBE_DEFER;
+
+		return rc;
+	}
+
+	locomo_lcd_program_adsync(lcd);
+
+	lcd_dev = devm_lcd_device_register(&dev->dev, "locomo", &dev->dev, lcd,
+			&locomo_lcd_ops);
+	if (IS_ERR(lcd_dev)) {
+		rc = PTR_ERR(lcd_dev);
+		goto err;
+	}
+
+	platform_set_drvdata(dev, lcd_dev);
+
+	lcd_set_power(lcd_dev, FB_BLANK_UNBLANK);
+
+	return 0;
+
+err:
+	locomo_lcd_disable_adsync(lcd);
+	iio_channel_release(lcd->comadj);
+
+	return rc;
+}
+
+static int locomo_lcd_remove(struct platform_device *dev)
+{
+	struct lcd_device *ldev = platform_get_drvdata(dev);
+	struct locomo_lcd *lcd = lcd_get_data(ldev);
+
+	locomo_lcd_off(lcd);
+
+	locomo_lcd_disable_adsync(lcd);
+
+	iio_channel_release(lcd->comadj);
+
+	return 0;
+}
+
+static void locomo_lcd_shutdown(struct platform_device *dev)
+{
+	struct lcd_device *ldev = platform_get_drvdata(dev);
+	struct locomo_lcd *lcd = lcd_get_data(ldev);
+
+	locomo_lcd_off(lcd);
+
+	locomo_lcd_disable_adsync(lcd);
+}
+
+static struct platform_driver locomo_lcd_driver = {
+	.driver = {
+		.name	= "locomo-lcd",
+		.pm	= LOCOMOLCD_PM,
+	},
+	.probe	= locomo_lcd_probe,
+	.remove	= locomo_lcd_remove,
+	.shutdown = locomo_lcd_shutdown,
+};
+
+module_platform_driver(locomo_lcd_driver);
+
+MODULE_AUTHOR("John Lenz <lenz@cs.wisc.edu>");
+MODULE_AUTHOR("Pavel Machek <pavel@ucw.cz>");
+MODULE_DESCRIPTION("LoCoMo LCD driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:locomo-lcd");