--- /dev/null
+/*
+ * 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,
+ <v_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 = <v350qv_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");
Code Review / kvmfornfv.git / blobdiff