/* * 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; 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_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 __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); if (!lcd->buffer) { ret = -ENOMEM; goto out_free_lcd; } ld = lcd_device_register("ltv350qv", &spi->dev, lcd, <v_ops); if (IS_ERR(ld)) { ret = PTR_ERR(ld); goto out_free_buffer; } 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_buffer: kfree(lcd->buffer); 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->buffer); kfree(lcd); return 0; } #ifdef CONFIG_PM static int ltv350qv_suspend(struct spi_device *spi, pm_message_t state) { struct ltv350qv *lcd = dev_get_drvdata(&spi->dev); return ltv350qv_power(lcd, FB_BLANK_POWERDOWN); } static int ltv350qv_resume(struct spi_device *spi) { struct ltv350qv *lcd = dev_get_drvdata(&spi->dev); return ltv350qv_power(lcd, FB_BLANK_UNBLANK); } #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 (Atmel)"); MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("spi:ltv350qv");