[PATCH 05/15] video: backlight: add new locomo backlight driver

[Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>]

Add new simple backlight driver - it cares only about PWM/frontlight
part of LoCoMo, it does not touch TFT settings and does not export TFT
power control.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
---
 drivers/video/backlight/Kconfig     |   6 +-
 drivers/video/backlight/Makefile    |   2 +-
 drivers/video/backlight/locomo_bl.c | 171 ++++++++++++++++++++++++++++++++++++
 3 files changed, 175 insertions(+), 4 deletions(-)
 create mode 100644 drivers/video/backlight/locomo_bl.c

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 8d03924..03b77b33 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -218,12 +218,12 @@ config BACKLIGHT_LM3533
 	  levels.
 
 config BACKLIGHT_LOCOMO
-	tristate "Sharp LOCOMO LCD/Backlight Driver"
-	depends on SHARP_LOCOMO
+	tristate "Sharp LOCOMO Backlight 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/backlight driver.
+	  enable the backlight driver.
 
 config BACKLIGHT_OMAP1
 	tristate "OMAP1 PWL-based LCD Backlight"
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index fcd50b73..2a61b7e 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -39,7 +39,7 @@ obj-$(CONFIG_BACKLIGHT_IPAQ_MICRO)	+= ipaq_micro_bl.o
 obj-$(CONFIG_BACKLIGHT_LM3533)		+= lm3533_bl.o
 obj-$(CONFIG_BACKLIGHT_LM3630A)		+= lm3630a_bl.o
 obj-$(CONFIG_BACKLIGHT_LM3639)		+= lm3639_bl.o
-obj-$(CONFIG_BACKLIGHT_LOCOMO)		+= locomolcd.o
+obj-$(CONFIG_BACKLIGHT_LOCOMO)		+= locomo_bl.o
 obj-$(CONFIG_BACKLIGHT_LP855X)		+= lp855x_bl.o
 obj-$(CONFIG_BACKLIGHT_LP8788)		+= lp8788_bl.o
 obj-$(CONFIG_BACKLIGHT_LV5207LP)	+= lv5207lp.o
diff --git a/drivers/video/backlight/locomo_bl.c b/drivers/video/backlight/locomo_bl.c
new file mode 100644
index 0000000..cec1b51
--- /dev/null
+++ b/drivers/video/backlight/locomo_bl.c
@@ -0,0 +1,171 @@
+/*
+ * 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/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/mfd/locomo.h>
+
+struct locomo_bl {
+	void __iomem *regs;
+	int current_intensity;
+	int gpio_fl_vr;
+};
+
+static const struct {
+	u16 duty, bpwf;
+	bool vr;
+} locomo_bl_pwm[] = {
+	{ 0, 161, false },
+	{ 117, 161, false },
+	{ 163, 148, false },
+	{ 194, 161, false },
+	{ 194, 161, true },
+};
+
+static int locomo_bl_set_intensity(struct backlight_device *bd)
+{
+	int intensity = bd->props.brightness;
+	struct locomo_bl *bl = dev_get_drvdata(&bd->dev);
+
+	if (bd->props.power != FB_BLANK_UNBLANK)
+		intensity = 0;
+	if (bd->props.fb_blank != FB_BLANK_UNBLANK)
+		intensity = 0;
+	if (bd->props.state & BL_CORE_SUSPENDED)
+		intensity = 0;
+
+	gpio_set_value(bl->gpio_fl_vr, locomo_bl_pwm[intensity].vr);
+
+	writew(locomo_bl_pwm[intensity].bpwf, bl->regs + LOCOMO_ALS);
+	udelay(100);
+	writew(locomo_bl_pwm[intensity].duty, bl->regs + LOCOMO_ALD);
+	udelay(100);
+	writew(locomo_bl_pwm[intensity].bpwf | LOCOMO_ALC_EN,
+			bl->regs + LOCOMO_ALS);
+
+	bl->current_intensity = intensity;
+	if (bd->props.state & BL_CORE_SUSPENDED)
+		writew(0x00, bl->regs + LOCOMO_ALS);
+
+	return 0;
+}
+
+static int locomo_bl_get_intensity(struct backlight_device *bd)
+{
+	struct locomo_bl *bl = dev_get_drvdata(&bd->dev);
+
+	return bl->current_intensity;
+}
+
+static const struct backlight_ops locomo_bl_ops = {
+	.options	= BL_CORE_SUSPENDRESUME,
+	.get_brightness = locomo_bl_get_intensity,
+	.update_status  = locomo_bl_set_intensity,
+};
+
+static int locomo_bl_probe(struct platform_device *dev)
+{
+	struct backlight_properties props;
+	struct resource *res;
+	struct locomo_bl_platform_data *pdata;
+	struct locomo_bl *bl;
+	struct backlight_device *locomo_bl_device;
+	int rc;
+
+	bl = devm_kmalloc(&dev->dev, sizeof(struct locomo_bl), GFP_KERNEL);
+	if (!bl)
+		return -ENOMEM;
+
+	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+	bl->regs = devm_ioremap_resource(&dev->dev, res);
+	if (!bl->regs)
+		return -EINVAL;
+
+	pdata = dev_get_platdata(&dev->dev);
+	if (!pdata)
+		return -EINVAL;
+
+	bl->gpio_fl_vr = pdata->gpio_fl_vr;
+	rc = devm_gpio_request_one(&dev->dev, bl->gpio_fl_vr,
+			GPIOF_OUT_INIT_LOW, "FL VR");
+	if (rc)
+		return rc;
+
+	writew(0, bl->regs + LOCOMO_ALS);
+	writew(0, bl->regs + LOCOMO_ALD);
+
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_RAW;
+	props.max_brightness = ARRAY_SIZE(locomo_bl_pwm) - 1;
+	props.brightness = props.max_brightness / 2;
+	locomo_bl_device = backlight_device_register("locomo-bl",
+						&dev->dev, bl,
+						&locomo_bl_ops, &props);
+
+	if (IS_ERR(locomo_bl_device))
+		return PTR_ERR(locomo_bl_device);
+
+	platform_set_drvdata(dev, locomo_bl_device);
+
+	/* Set up frontlight so that screen is readable */
+	backlight_update_status(locomo_bl_device);
+
+	return 0;
+}
+
+static int locomo_bl_remove(struct platform_device *dev)
+{
+	struct backlight_device *locomo_bl_device = platform_get_drvdata(dev);
+
+	locomo_bl_device->props.brightness = 0;
+	locomo_bl_device->props.power = 0;
+	locomo_bl_set_intensity(locomo_bl_device);
+
+	backlight_device_unregister(locomo_bl_device);
+
+	return 0;
+}
+
+static void locomo_bl_shutdown(struct platform_device *dev)
+{
+	struct backlight_device *locomo_bl_device = platform_get_drvdata(dev);
+
+	locomo_bl_device->props.brightness = 0;
+	locomo_bl_device->props.power = 0;
+	locomo_bl_set_intensity(locomo_bl_device);
+}
+
+static struct platform_driver locomo_bl_driver = {
+	.driver = {
+		.name	= "locomo-backlight",
+		.owner	= THIS_MODULE,
+	},
+	.probe	= locomo_bl_probe,
+	.remove	= locomo_bl_remove,
+	/* Turn off bl on power off/reboot */
+	.shutdown = locomo_bl_shutdown,
+};
+
+module_platform_driver(locomo_bl_driver);
+
+MODULE_AUTHOR("John Lenz <lenz@cs.wisc.edu>, Pavel Machek <pavel@ucw.cz>");
+MODULE_DESCRIPTION("Collie Backlight driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:locomo-backlight");
-- 
2.1.1