diff options
Diffstat (limited to 'drivers/video/backlight/ltv350qv.c')
| -rw-r--r-- | drivers/video/backlight/ltv350qv.c | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/drivers/video/backlight/ltv350qv.c b/drivers/video/backlight/ltv350qv.c new file mode 100644 index 000000000..d54f501e4 --- /dev/null +++ b/drivers/video/backlight/ltv350qv.c @@ -0,0 +1,306 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Power control for Samsung LTV350QV Quarter VGA LCD Panel + * + * Copyright (C) 2006, 2007 Atmel Corporation + */ +#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. + * + * 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 void ltv350qv_remove(struct spi_device *spi) +{ + struct ltv350qv *lcd = spi_get_drvdata(spi); + + ltv350qv_power(lcd, FB_BLANK_POWERDOWN); +} + +#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", + .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"); |