This patch adds support for powering on and off the Samsung LTV350QV
LCD panel via SPI. The driver responds to framebuffer power
management, it powers off the panel on reboot/halt/poweroff, and it
can also be controlled through sysfs. The panel is powered up when the
module is loaded and off when the module is unloaded.
Signed-off-by: Haavard Skinnemoen <[email protected]>
---
I agree that the write_reg() macro with embedded goto is ugly, so I've
removed it. I've also added some code that tries to recover by powering
down the display if the power-on sequence fails halfway through.
The driver has been rebased onto
http://git.o-hand.com/?p=linux-rpurdie-backlight;a=shortlog;h=for-mm
so it should apply nicely on top of David's Kconfig patch.
drivers/video/backlight/Kconfig | 12 ++
drivers/video/backlight/Makefile | 2 +
drivers/video/backlight/ltv350qv.c | 340 ++++++++++++++++++++++++++++++++++++
drivers/video/backlight/ltv350qv.h | 95 ++++++++++
4 files changed, 449 insertions(+), 0 deletions(-)
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 2580f5f..b6f936a 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -24,6 +24,18 @@ config LCD_CLASS_DEVICE
To have support for your specific LCD panel you will have to
select the proper drivers which depend on this option.
+config LCD_LTV350QV
+ tristate "Samsung LTV350QV LCD Panel"
+ depends on LCD_CLASS_DEVICE && SPI_MASTER
+ default n
+ help
+ If you have a Samsung LTV350QV LCD panel, say y to include a
+ power control driver for it. The panel starts up in power
+ off state, so you need this driver in order to see any
+ output.
+
+ The LTV350QV panel is present on all ATSTK1000 boards.
+
#
# Backlight
#
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index c6e2266..965a78b 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -1,6 +1,8 @@
# Backlight & LCD drivers
obj-$(CONFIG_LCD_CLASS_DEVICE) += lcd.o
+obj-$(CONFIG_LCD_LTV350QV) += ltv350qv.o
+
obj-$(CONFIG_BACKLIGHT_CLASS_DEVICE) += backlight.o
obj-$(CONFIG_BACKLIGHT_CORGI) += corgi_bl.o
obj-$(CONFIG_BACKLIGHT_HP680) += hp680_bl.o
diff --git a/drivers/video/backlight/ltv350qv.c b/drivers/video/backlight/ltv350qv.c
new file mode 100644
index 0000000..342b97a
--- /dev/null
+++ b/drivers/video/backlight/ltv350qv.c
@@ -0,0 +1,340 @@
+/*
+ * 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/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,
+ .cs_change = 1,
+ };
+
+ 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;
+ msleep(15);
+
+ /* 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);
+ msleep(1);
+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 */
+ msleep(1);
+
+ /* 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 = class_get_devdata(&ld->class_dev);
+ return ltv350qv_power(lcd, power);
+}
+
+static int ltv350qv_get_power(struct lcd_device *ld)
+{
+ struct ltv350qv *lcd;
+
+ lcd = class_get_devdata(&ld->class_dev);
+ return lcd->power;
+}
+
+static struct lcd_ops ltv_ops = {
+ .get_power = ltv350qv_get_power,
+ .set_power = ltv350qv_set_power,
+};
+
+static int __devinit ltv350qv_probe(struct spi_device *spi)
+{
+ struct ltv350qv *lcd;
+ struct lcd_device *ld;
+ int ret;
+
+ lcd = kzalloc(sizeof(struct ltv350qv), GFP_KERNEL);
+ if (!lcd)
+ return -ENOMEM;
+
+ lcd->spi = spi;
+ lcd->power = FB_BLANK_POWERDOWN;
+ lcd->buffer = kzalloc(8, GFP_KERNEL);
+
+ ld = lcd_device_register("ltv350qv", lcd, <v_ops);
+ if (IS_ERR(ld)) {
+ ret = PTR_ERR(ld);
+ goto out_free_lcd;
+ }
+ lcd->ld = ld;
+
+ ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK);
+ if (ret)
+ goto out_unregister;
+
+ dev_set_drvdata(&spi->dev, lcd);
+
+ return 0;
+
+out_unregister:
+ lcd_device_unregister(ld);
+out_free_lcd:
+ kfree(lcd);
+ return ret;
+}
+
+static int __devexit ltv350qv_remove(struct spi_device *spi)
+{
+ struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
+
+ ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
+ lcd_device_unregister(lcd->ld);
+ kfree(lcd);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int ltv350qv_suspend(struct spi_device *spi,
+ pm_message_t state, u32 level)
+{
+ struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
+
+ if (level == SUSPEND_POWER_DOWN)
+ return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
+
+ return 0;
+}
+
+static int ltv350qv_resume(struct spi_device *spi, u32 level)
+{
+ struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
+
+ if (level == RESUME_POWER_ON)
+ return ltv350qv_power(lcd, FB_BLANK_UNBLANK);
+
+ return 0;
+}
+#else
+#define ltv350qv_suspend NULL
+#define ltv350qv_resume NULL
+#endif
+
+/* Power down all displays on reboot, poweroff or halt */
+static void ltv350qv_shutdown(struct spi_device *spi)
+{
+ struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
+
+ ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
+}
+
+static struct spi_driver ltv350qv_driver = {
+ .driver = {
+ .name = "ltv350qv",
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+ },
+
+ .probe = ltv350qv_probe,
+ .remove = __devexit_p(ltv350qv_remove),
+ .shutdown = ltv350qv_shutdown,
+ .suspend = ltv350qv_suspend,
+ .resume = ltv350qv_resume,
+};
+
+static int __init ltv350qv_init(void)
+{
+ return spi_register_driver(<v350qv_driver);
+}
+
+static void __exit ltv350qv_exit(void)
+{
+ spi_unregister_driver(<v350qv_driver);
+}
+module_init(ltv350qv_init);
+module_exit(ltv350qv_exit);
+
+MODULE_AUTHOR("Haavard Skinnemoen <[email protected]>");
+MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/video/backlight/ltv350qv.h b/drivers/video/backlight/ltv350qv.h
new file mode 100644
index 0000000..189112e
--- /dev/null
+++ b/drivers/video/backlight/ltv350qv.h
@@ -0,0 +1,95 @@
+/*
+ * Register definitions 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.
+ */
+#ifndef __LTV350QV_H
+#define __LTV350QV_H
+
+#define LTV_OPC_INDEX 0x74
+#define LTV_OPC_DATA 0x76
+
+#define LTV_ID 0x00 /* ID Read */
+#define LTV_IFCTL 0x01 /* Display Interface Control */
+#define LTV_DATACTL 0x02 /* Display Data Control */
+#define LTV_ENTRY_MODE 0x03 /* Entry Mode */
+#define LTV_GATECTL1 0x04 /* Gate Control 1 */
+#define LTV_GATECTL2 0x05 /* Gate Control 2 */
+#define LTV_VBP 0x06 /* Vertical Back Porch */
+#define LTV_HBP 0x07 /* Horizontal Back Porch */
+#define LTV_SOTCTL 0x08 /* Source Output Timing Control */
+#define LTV_PWRCTL1 0x09 /* Power Control 1 */
+#define LTV_PWRCTL2 0x0a /* Power Control 2 */
+#define LTV_GAMMA(x) (0x10 + (x)) /* Gamma control */
+
+/* Bit definitions for LTV_IFCTL */
+#define LTV_IM (1 << 15)
+#define LTV_NMD (1 << 14)
+#define LTV_SSMD (1 << 13)
+#define LTV_REV (1 << 7)
+#define LTV_NL(x) (((x) & 0x001f) << 0)
+
+/* Bit definitions for LTV_DATACTL */
+#define LTV_DS_SAME (0 << 12)
+#define LTV_DS_D_TO_S (1 << 12)
+#define LTV_DS_S_TO_D (2 << 12)
+#define LTV_CHS_384 (0 << 9)
+#define LTV_CHS_480 (1 << 9)
+#define LTV_CHS_492 (2 << 9)
+#define LTV_DF_RGB (0 << 6)
+#define LTV_DF_RGBX (1 << 6)
+#define LTV_DF_XRGB (2 << 6)
+#define LTV_RGB_RGB (0 << 2)
+#define LTV_RGB_BGR (1 << 2)
+#define LTV_RGB_GRB (2 << 2)
+#define LTV_RGB_RBG (3 << 2)
+
+/* Bit definitions for LTV_ENTRY_MODE */
+#define LTV_VSPL_ACTIVE_LOW (0 << 15)
+#define LTV_VSPL_ACTIVE_HIGH (1 << 15)
+#define LTV_HSPL_ACTIVE_LOW (0 << 14)
+#define LTV_HSPL_ACTIVE_HIGH (1 << 14)
+#define LTV_DPL_SAMPLE_RISING (0 << 13)
+#define LTV_DPL_SAMPLE_FALLING (1 << 13)
+#define LTV_EPL_ACTIVE_LOW (0 << 12)
+#define LTV_EPL_ACTIVE_HIGH (1 << 12)
+#define LTV_SS_LEFT_TO_RIGHT (0 << 8)
+#define LTV_SS_RIGHT_TO_LEFT (1 << 8)
+#define LTV_STB (1 << 1)
+
+/* Bit definitions for LTV_GATECTL1 */
+#define LTV_CLW(x) (((x) & 0x0007) << 12)
+#define LTV_GAON (1 << 5)
+#define LTV_SDR (1 << 3)
+
+/* Bit definitions for LTV_GATECTL2 */
+#define LTV_NW_INV_FRAME (0 << 14)
+#define LTV_NW_INV_1LINE (1 << 14)
+#define LTV_NW_INV_2LINE (2 << 14)
+#define LTV_DSC (1 << 12)
+#define LTV_GIF (1 << 8)
+#define LTV_FHN (1 << 7)
+#define LTV_FTI(x) (((x) & 0x0003) << 4)
+#define LTV_FWI(x) (((x) & 0x0003) << 0)
+
+/* Bit definitions for LTV_SOTCTL */
+#define LTV_SDT(x) (((x) & 0x0007) << 10)
+#define LTV_EQ(x) (((x) & 0x0007) << 2)
+
+/* Bit definitions for LTV_PWRCTL1 */
+#define LTV_VCOM_DISABLE (1 << 14)
+#define LTV_VCOMOUT_ENABLE (1 << 11)
+#define LTV_POWER_ON (1 << 9)
+#define LTV_DRIVE_CURRENT(x) (((x) & 0x0007) << 4) /* 0=off, 5=max */
+#define LTV_SUPPLY_CURRENT(x) (((x) & 0x0007) << 0) /* 0=off, 5=max */
+
+/* Bit definitions for LTV_PWRCTL2 */
+#define LTV_VCOML_ENABLE (1 << 13)
+#define LTV_VCOML_VOLTAGE(x) (((x) & 0x001f) << 8) /* 0=1V, 31=-1V */
+#define LTV_VCOMH_VOLTAGE(x) (((x) & 0x001f) << 0) /* 0=3V, 31=4.5V */
+
+#endif /* __LTV350QV_H */
--
1.4.4.4
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