307 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Power control for Samsung LTV350QV Quarter VGA LCD Panel4 *5 * Copyright (C) 2006, 2007 Atmel Corporation6 */7#include <linux/delay.h>8#include <linux/err.h>9#include <linux/fb.h>10#include <linux/init.h>11#include <linux/lcd.h>12#include <linux/module.h>13#include <linux/slab.h>14#include <linux/spi/spi.h>15 16#include "ltv350qv.h"17 18#define POWER_IS_ON(pwr) ((pwr) <= FB_BLANK_NORMAL)19 20struct ltv350qv {21 struct spi_device *spi;22 u8 *buffer;23 int power;24 struct lcd_device *ld;25};26 27/*28 * The power-on and power-off sequences are taken from the29 * LTV350QV-F04 data sheet from Samsung. The register definitions are30 * taken from the S6F2002 command list also from Samsung.31 *32 * There's still some voodoo going on here, but it's a lot better than33 * in the first incarnation of the driver where all we had was the raw34 * numbers from the initialization sequence.35 */36static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val)37{38 struct spi_message msg;39 struct spi_transfer index_xfer = {40 .len = 3,41 .cs_change = 1,42 };43 struct spi_transfer value_xfer = {44 .len = 3,45 };46 47 spi_message_init(&msg);48 49 /* register index */50 lcd->buffer[0] = LTV_OPC_INDEX;51 lcd->buffer[1] = 0x00;52 lcd->buffer[2] = reg & 0x7f;53 index_xfer.tx_buf = lcd->buffer;54 spi_message_add_tail(&index_xfer, &msg);55 56 /* register value */57 lcd->buffer[4] = LTV_OPC_DATA;58 lcd->buffer[5] = val >> 8;59 lcd->buffer[6] = val;60 value_xfer.tx_buf = lcd->buffer + 4;61 spi_message_add_tail(&value_xfer, &msg);62 63 return spi_sync(lcd->spi, &msg);64}65 66/* The comments are taken straight from the data sheet */67static int ltv350qv_power_on(struct ltv350qv *lcd)68{69 int ret;70 71 /* Power On Reset Display off State */72 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000))73 goto err;74 usleep_range(15000, 16000);75 76 /* Power Setting Function 1 */77 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE))78 goto err;79 if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE))80 goto err_power1;81 82 /* Power Setting Function 2 */83 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1,84 LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)85 | LTV_SUPPLY_CURRENT(5)))86 goto err_power2;87 88 msleep(55);89 90 /* Instruction Setting */91 ret = ltv350qv_write_reg(lcd, LTV_IFCTL,92 LTV_NMD | LTV_REV | LTV_NL(0x1d));93 ret |= ltv350qv_write_reg(lcd, LTV_DATACTL,94 LTV_DS_SAME | LTV_CHS_48095 | LTV_DF_RGB | LTV_RGB_BGR);96 ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE,97 LTV_VSPL_ACTIVE_LOW98 | LTV_HSPL_ACTIVE_LOW99 | LTV_DPL_SAMPLE_RISING100 | LTV_EPL_ACTIVE_LOW101 | LTV_SS_RIGHT_TO_LEFT);102 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3));103 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,104 LTV_NW_INV_1LINE | LTV_FWI(3));105 ret |= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a);106 ret |= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021);107 ret |= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) | LTV_EQ(0));108 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103);109 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301);110 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f);111 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f);112 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707);113 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307);114 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707);115 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000);116 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004);117 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000);118 if (ret)119 goto err_settings;120 121 /* Wait more than 2 frames */122 msleep(20);123 124 /* Display On Sequence */125 ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,126 LTV_VCOM_DISABLE | LTV_VCOMOUT_ENABLE127 | LTV_POWER_ON | LTV_DRIVE_CURRENT(5)128 | LTV_SUPPLY_CURRENT(5));129 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,130 LTV_NW_INV_1LINE | LTV_DSC | LTV_FWI(3));131 if (ret)132 goto err_disp_on;133 134 /* Display should now be ON. Phew. */135 return 0;136 137err_disp_on:138 /*139 * Try to recover. Error handling probably isn't very useful140 * at this point, just make a best effort to switch the panel141 * off.142 */143 ltv350qv_write_reg(lcd, LTV_PWRCTL1,144 LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)145 | LTV_SUPPLY_CURRENT(5));146 ltv350qv_write_reg(lcd, LTV_GATECTL2,147 LTV_NW_INV_1LINE | LTV_FWI(3));148err_settings:149err_power2:150err_power1:151 ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);152 usleep_range(1000, 1100);153err:154 ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);155 return -EIO;156}157 158static int ltv350qv_power_off(struct ltv350qv *lcd)159{160 int ret;161 162 /* Display Off Sequence */163 ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,164 LTV_VCOM_DISABLE165 | LTV_DRIVE_CURRENT(5)166 | LTV_SUPPLY_CURRENT(5));167 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,168 LTV_NW_INV_1LINE | LTV_FWI(3));169 170 /* Power down setting 1 */171 ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);172 173 /* Wait at least 1 ms */174 usleep_range(1000, 1100);175 176 /* Power down setting 2 */177 ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);178 179 /*180 * No point in trying to recover here. If we can't switch the181 * panel off, what are we supposed to do other than inform the182 * user about the failure?183 */184 if (ret)185 return -EIO;186 187 /* Display power should now be OFF */188 return 0;189}190 191static int ltv350qv_power(struct ltv350qv *lcd, int power)192{193 int ret = 0;194 195 if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))196 ret = ltv350qv_power_on(lcd);197 else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))198 ret = ltv350qv_power_off(lcd);199 200 if (!ret)201 lcd->power = power;202 203 return ret;204}205 206static int ltv350qv_set_power(struct lcd_device *ld, int power)207{208 struct ltv350qv *lcd = lcd_get_data(ld);209 210 return ltv350qv_power(lcd, power);211}212 213static int ltv350qv_get_power(struct lcd_device *ld)214{215 struct ltv350qv *lcd = lcd_get_data(ld);216 217 return lcd->power;218}219 220static const struct lcd_ops ltv_ops = {221 .get_power = ltv350qv_get_power,222 .set_power = ltv350qv_set_power,223};224 225static int ltv350qv_probe(struct spi_device *spi)226{227 struct ltv350qv *lcd;228 struct lcd_device *ld;229 int ret;230 231 lcd = devm_kzalloc(&spi->dev, sizeof(struct ltv350qv), GFP_KERNEL);232 if (!lcd)233 return -ENOMEM;234 235 lcd->spi = spi;236 lcd->power = FB_BLANK_POWERDOWN;237 lcd->buffer = devm_kzalloc(&spi->dev, 8, GFP_KERNEL);238 if (!lcd->buffer)239 return -ENOMEM;240 241 ld = devm_lcd_device_register(&spi->dev, "ltv350qv", &spi->dev, lcd,242 <v_ops);243 if (IS_ERR(ld))244 return PTR_ERR(ld);245 246 lcd->ld = ld;247 248 ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK);249 if (ret)250 return ret;251 252 spi_set_drvdata(spi, lcd);253 254 return 0;255}256 257static void ltv350qv_remove(struct spi_device *spi)258{259 struct ltv350qv *lcd = spi_get_drvdata(spi);260 261 ltv350qv_power(lcd, FB_BLANK_POWERDOWN);262}263 264#ifdef CONFIG_PM_SLEEP265static int ltv350qv_suspend(struct device *dev)266{267 struct ltv350qv *lcd = dev_get_drvdata(dev);268 269 return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);270}271 272static int ltv350qv_resume(struct device *dev)273{274 struct ltv350qv *lcd = dev_get_drvdata(dev);275 276 return ltv350qv_power(lcd, FB_BLANK_UNBLANK);277}278#endif279 280static SIMPLE_DEV_PM_OPS(ltv350qv_pm_ops, ltv350qv_suspend, ltv350qv_resume);281 282/* Power down all displays on reboot, poweroff or halt */283static void ltv350qv_shutdown(struct spi_device *spi)284{285 struct ltv350qv *lcd = spi_get_drvdata(spi);286 287 ltv350qv_power(lcd, FB_BLANK_POWERDOWN);288}289 290static struct spi_driver ltv350qv_driver = {291 .driver = {292 .name = "ltv350qv",293 .pm = <v350qv_pm_ops,294 },295 296 .probe = ltv350qv_probe,297 .remove = ltv350qv_remove,298 .shutdown = ltv350qv_shutdown,299};300 301module_spi_driver(ltv350qv_driver);302 303MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");304MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");305MODULE_LICENSE("GPL");306MODULE_ALIAS("spi:ltv350qv");307