Initial import

1 files changed, 312 insertions, 0 deletions

diff --git a/drivers/video/backlight/ltv350qv.c b/drivers/video/backlight/ltv350qv.c
new file mode 100644
index 000000000..383f550e1
--- /dev/null
+++ b/drivers/video/backlight/ltv350qv.c
@@ -0,0 +1,312 @@
+/*
+ * Power control for Samsung LTV350QV Quarter VGA LCD Panel
+ *
+ * Copyright (C) 2006, 2007 Atmel Corporation
+ *
+ * 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/delay.h>
+#include <linux/err.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/lcd.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+
+#include "ltv350qv.h"
+
+#define POWER_IS_ON(pwr)	((pwr) <= FB_BLANK_NORMAL)
+
+struct ltv350qv {
+	struct spi_device	*spi;
+	u8			*buffer;
+	int			power;
+	struct lcd_device	*ld;
+};
+
+/*
+ * The power-on and power-off sequences are taken from the
+ * LTV350QV-F04 data sheet from Samsung. The register definitions are
+ * taken from the S6F2002 command list also from Samsung. Both
+ * documents are distributed with the AVR32 Linux BSP CD from Atmel.
+ *
+ * There's still some voodoo going on here, but it's a lot better than
+ * in the first incarnation of the driver where all we had was the raw
+ * numbers from the initialization sequence.
+ */
+static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val)
+{
+	struct spi_message msg;
+	struct spi_transfer index_xfer = {
+		.len		= 3,
+		.cs_change	= 1,
+	};
+	struct spi_transfer value_xfer = {
+		.len		= 3,
+	};
+
+	spi_message_init(&msg);
+
+	/* register index */
+	lcd->buffer[0] = LTV_OPC_INDEX;
+	lcd->buffer[1] = 0x00;
+	lcd->buffer[2] = reg & 0x7f;
+	index_xfer.tx_buf = lcd->buffer;
+	spi_message_add_tail(&index_xfer, &msg);
+
+	/* register value */
+	lcd->buffer[4] = LTV_OPC_DATA;
+	lcd->buffer[5] = val >> 8;
+	lcd->buffer[6] = val;
+	value_xfer.tx_buf = lcd->buffer + 4;
+	spi_message_add_tail(&value_xfer, &msg);
+
+	return spi_sync(lcd->spi, &msg);
+}
+
+/* The comments are taken straight from the data sheet */
+static int ltv350qv_power_on(struct ltv350qv *lcd)
+{
+	int ret;
+
+	/* Power On Reset Display off State */
+	if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000))
+		goto err;
+	usleep_range(15000, 16000);
+
+	/* Power Setting Function 1 */
+	if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE))
+		goto err;
+	if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE))
+		goto err_power1;
+
+	/* Power Setting Function 2 */
+	if (ltv350qv_write_reg(lcd, LTV_PWRCTL1,
+			       LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
+			       | LTV_SUPPLY_CURRENT(5)))
+		goto err_power2;
+
+	msleep(55);
+
+	/* Instruction Setting */
+	ret = ltv350qv_write_reg(lcd, LTV_IFCTL,
+				 LTV_NMD | LTV_REV | LTV_NL(0x1d));
+	ret |= ltv350qv_write_reg(lcd, LTV_DATACTL,
+				  LTV_DS_SAME | LTV_CHS_480
+				  | LTV_DF_RGB | LTV_RGB_BGR);
+	ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE,
+				  LTV_VSPL_ACTIVE_LOW
+				  | LTV_HSPL_ACTIVE_LOW
+				  | LTV_DPL_SAMPLE_RISING
+				  | LTV_EPL_ACTIVE_LOW
+				  | LTV_SS_RIGHT_TO_LEFT);
+	ret |= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3));
+	ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
+				  LTV_NW_INV_1LINE | LTV_FWI(3));
+	ret |= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a);
+	ret |= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021);
+	ret |= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) | LTV_EQ(0));
+	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103);
+	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301);
+	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f);
+	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f);
+	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707);
+	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307);
+	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707);
+	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000);
+	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004);
+	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000);
+	if (ret)
+		goto err_settings;
+
+	/* Wait more than 2 frames */
+	msleep(20);
+
+	/* Display On Sequence */
+	ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
+				 LTV_VCOM_DISABLE | LTV_VCOMOUT_ENABLE
+				 | LTV_POWER_ON | LTV_DRIVE_CURRENT(5)
+				 | LTV_SUPPLY_CURRENT(5));
+	ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
+				  LTV_NW_INV_1LINE | LTV_DSC | LTV_FWI(3));
+	if (ret)
+		goto err_disp_on;
+
+	/* Display should now be ON. Phew. */
+	return 0;
+
+err_disp_on:
+	/*
+	 * Try to recover. Error handling probably isn't very useful
+	 * at this point, just make a best effort to switch the panel
+	 * off.
+	 */
+	ltv350qv_write_reg(lcd, LTV_PWRCTL1,
+			   LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
+			   | LTV_SUPPLY_CURRENT(5));
+	ltv350qv_write_reg(lcd, LTV_GATECTL2,
+			   LTV_NW_INV_1LINE | LTV_FWI(3));
+err_settings:
+err_power2:
+err_power1:
+	ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
+	usleep_range(1000, 1100);
+err:
+	ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
+	return -EIO;
+}
+
+static int ltv350qv_power_off(struct ltv350qv *lcd)
+{
+	int ret;
+
+	/* Display Off Sequence */
+	ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
+				 LTV_VCOM_DISABLE
+				 | LTV_DRIVE_CURRENT(5)
+				 | LTV_SUPPLY_CURRENT(5));
+	ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
+				  LTV_NW_INV_1LINE | LTV_FWI(3));
+
+	/* Power down setting 1 */
+	ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
+
+	/* Wait at least 1 ms */
+	usleep_range(1000, 1100);
+
+	/* Power down setting 2 */
+	ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
+
+	/*
+	 * No point in trying to recover here. If we can't switch the
+	 * panel off, what are we supposed to do other than inform the
+	 * user about the failure?
+	 */
+	if (ret)
+		return -EIO;
+
+	/* Display power should now be OFF */
+	return 0;
+}
+
+static int ltv350qv_power(struct ltv350qv *lcd, int power)
+{
+	int ret = 0;
+
+	if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))
+		ret = ltv350qv_power_on(lcd);
+	else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))
+		ret = ltv350qv_power_off(lcd);
+
+	if (!ret)
+		lcd->power = power;
+
+	return ret;
+}
+
+static int ltv350qv_set_power(struct lcd_device *ld, int power)
+{
+	struct ltv350qv *lcd = lcd_get_data(ld);
+
+	return ltv350qv_power(lcd, power);
+}
+
+static int ltv350qv_get_power(struct lcd_device *ld)
+{
+	struct ltv350qv *lcd = lcd_get_data(ld);
+
+	return lcd->power;
+}
+
+static struct lcd_ops ltv_ops = {
+	.get_power	= ltv350qv_get_power,
+	.set_power	= ltv350qv_set_power,
+};
+
+static int ltv350qv_probe(struct spi_device *spi)
+{
+	struct ltv350qv *lcd;
+	struct lcd_device *ld;
+	int ret;
+
+	lcd = devm_kzalloc(&spi->dev, sizeof(struct ltv350qv), GFP_KERNEL);
+	if (!lcd)
+		return -ENOMEM;
+
+	lcd->spi = spi;
+	lcd->power = FB_BLANK_POWERDOWN;
+	lcd->buffer = devm_kzalloc(&spi->dev, 8, GFP_KERNEL);
+	if (!lcd->buffer)
+		return -ENOMEM;
+
+	ld = devm_lcd_device_register(&spi->dev, "ltv350qv", &spi->dev, lcd,
+					&ltv_ops);
+	if (IS_ERR(ld))
+		return PTR_ERR(ld);
+
+	lcd->ld = ld;
+
+	ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK);
+	if (ret)
+		return ret;
+
+	spi_set_drvdata(spi, lcd);
+
+	return 0;
+}
+
+static int ltv350qv_remove(struct spi_device *spi)
+{
+	struct ltv350qv *lcd = spi_get_drvdata(spi);
+
+	ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int ltv350qv_suspend(struct device *dev)
+{
+	struct ltv350qv *lcd = dev_get_drvdata(dev);
+
+	return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
+}
+
+static int ltv350qv_resume(struct device *dev)
+{
+	struct ltv350qv *lcd = dev_get_drvdata(dev);
+
+	return ltv350qv_power(lcd, FB_BLANK_UNBLANK);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(ltv350qv_pm_ops, ltv350qv_suspend, ltv350qv_resume);
+
+/* Power down all displays on reboot, poweroff or halt */
+static void ltv350qv_shutdown(struct spi_device *spi)
+{
+	struct ltv350qv *lcd = spi_get_drvdata(spi);
+
+	ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
+}
+
+static struct spi_driver ltv350qv_driver = {
+	.driver = {
+		.name		= "ltv350qv",
+		.owner		= THIS_MODULE,
+		.pm		= &ltv350qv_pm_ops,
+	},
+
+	.probe		= ltv350qv_probe,
+	.remove		= ltv350qv_remove,
+	.shutdown	= ltv350qv_shutdown,
+};
+
+module_spi_driver(ltv350qv_driver);
+
+MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
+MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:ltv350qv");