1 /* 2 * Power control for Samsung LTV350QV Quarter VGA LCD Panel 3 * 4 * Copyright (C) 2006, 2007 Atmel Corporation 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 #include <linux/delay.h> 11 #include <linux/err.h> 12 #include <linux/fb.h> 13 #include <linux/init.h> 14 #include <linux/lcd.h> 15 #include <linux/module.h> 16 #include <linux/slab.h> 17 #include <linux/spi/spi.h> 18 19 #include "ltv350qv.h" 20 21 #define POWER_IS_ON(pwr) ((pwr) <= FB_BLANK_NORMAL) 22 23 struct ltv350qv { 24 struct spi_device *spi; 25 u8 *buffer; 26 int power; 27 struct lcd_device *ld; 28 }; 29 30 /* 31 * The power-on and power-off sequences are taken from the 32 * LTV350QV-F04 data sheet from Samsung. The register definitions are 33 * taken from the S6F2002 command list also from Samsung. Both 34 * documents are distributed with the AVR32 Linux BSP CD from Atmel. 35 * 36 * There's still some voodoo going on here, but it's a lot better than 37 * in the first incarnation of the driver where all we had was the raw 38 * numbers from the initialization sequence. 39 */ 40 static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val) 41 { 42 struct spi_message msg; 43 struct spi_transfer index_xfer = { 44 .len = 3, 45 .cs_change = 1, 46 }; 47 struct spi_transfer value_xfer = { 48 .len = 3, 49 }; 50 51 spi_message_init(&msg); 52 53 /* register index */ 54 lcd->buffer[0] = LTV_OPC_INDEX; 55 lcd->buffer[1] = 0x00; 56 lcd->buffer[2] = reg & 0x7f; 57 index_xfer.tx_buf = lcd->buffer; 58 spi_message_add_tail(&index_xfer, &msg); 59 60 /* register value */ 61 lcd->buffer[4] = LTV_OPC_DATA; 62 lcd->buffer[5] = val >> 8; 63 lcd->buffer[6] = val; 64 value_xfer.tx_buf = lcd->buffer + 4; 65 spi_message_add_tail(&value_xfer, &msg); 66 67 return spi_sync(lcd->spi, &msg); 68 } 69 70 /* The comments are taken straight from the data sheet */ 71 static int ltv350qv_power_on(struct ltv350qv *lcd) 72 { 73 int ret; 74 75 /* Power On Reset Display off State */ 76 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000)) 77 goto err; 78 usleep_range(15000, 16000); 79 80 /* Power Setting Function 1 */ 81 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE)) 82 goto err; 83 if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE)) 84 goto err_power1; 85 86 /* Power Setting Function 2 */ 87 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 88 LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5) 89 | LTV_SUPPLY_CURRENT(5))) 90 goto err_power2; 91 92 msleep(55); 93 94 /* Instruction Setting */ 95 ret = ltv350qv_write_reg(lcd, LTV_IFCTL, 96 LTV_NMD | LTV_REV | LTV_NL(0x1d)); 97 ret |= ltv350qv_write_reg(lcd, LTV_DATACTL, 98 LTV_DS_SAME | LTV_CHS_480 99 | LTV_DF_RGB | LTV_RGB_BGR); 100 ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE, 101 LTV_VSPL_ACTIVE_LOW 102 | LTV_HSPL_ACTIVE_LOW 103 | LTV_DPL_SAMPLE_RISING 104 | LTV_EPL_ACTIVE_LOW 105 | LTV_SS_RIGHT_TO_LEFT); 106 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3)); 107 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2, 108 LTV_NW_INV_1LINE | LTV_FWI(3)); 109 ret |= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a); 110 ret |= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021); 111 ret |= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) | LTV_EQ(0)); 112 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103); 113 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301); 114 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f); 115 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f); 116 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707); 117 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307); 118 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707); 119 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000); 120 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004); 121 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000); 122 if (ret) 123 goto err_settings; 124 125 /* Wait more than 2 frames */ 126 msleep(20); 127 128 /* Display On Sequence */ 129 ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1, 130 LTV_VCOM_DISABLE | LTV_VCOMOUT_ENABLE 131 | LTV_POWER_ON | LTV_DRIVE_CURRENT(5) 132 | LTV_SUPPLY_CURRENT(5)); 133 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2, 134 LTV_NW_INV_1LINE | LTV_DSC | LTV_FWI(3)); 135 if (ret) 136 goto err_disp_on; 137 138 /* Display should now be ON. Phew. */ 139 return 0; 140 141 err_disp_on: 142 /* 143 * Try to recover. Error handling probably isn't very useful 144 * at this point, just make a best effort to switch the panel 145 * off. 146 */ 147 ltv350qv_write_reg(lcd, LTV_PWRCTL1, 148 LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5) 149 | LTV_SUPPLY_CURRENT(5)); 150 ltv350qv_write_reg(lcd, LTV_GATECTL2, 151 LTV_NW_INV_1LINE | LTV_FWI(3)); 152 err_settings: 153 err_power2: 154 err_power1: 155 ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000); 156 usleep_range(1000, 1100); 157 err: 158 ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE); 159 return -EIO; 160 } 161 162 static int ltv350qv_power_off(struct ltv350qv *lcd) 163 { 164 int ret; 165 166 /* Display Off Sequence */ 167 ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1, 168 LTV_VCOM_DISABLE 169 | LTV_DRIVE_CURRENT(5) 170 | LTV_SUPPLY_CURRENT(5)); 171 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2, 172 LTV_NW_INV_1LINE | LTV_FWI(3)); 173 174 /* Power down setting 1 */ 175 ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000); 176 177 /* Wait at least 1 ms */ 178 usleep_range(1000, 1100); 179 180 /* Power down setting 2 */ 181 ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE); 182 183 /* 184 * No point in trying to recover here. If we can't switch the 185 * panel off, what are we supposed to do other than inform the 186 * user about the failure? 187 */ 188 if (ret) 189 return -EIO; 190 191 /* Display power should now be OFF */ 192 return 0; 193 } 194 195 static int ltv350qv_power(struct ltv350qv *lcd, int power) 196 { 197 int ret = 0; 198 199 if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power)) 200 ret = ltv350qv_power_on(lcd); 201 else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power)) 202 ret = ltv350qv_power_off(lcd); 203 204 if (!ret) 205 lcd->power = power; 206 207 return ret; 208 } 209 210 static int ltv350qv_set_power(struct lcd_device *ld, int power) 211 { 212 struct ltv350qv *lcd = lcd_get_data(ld); 213 214 return ltv350qv_power(lcd, power); 215 } 216 217 static int ltv350qv_get_power(struct lcd_device *ld) 218 { 219 struct ltv350qv *lcd = lcd_get_data(ld); 220 221 return lcd->power; 222 } 223 224 static struct lcd_ops ltv_ops = { 225 .get_power = ltv350qv_get_power, 226 .set_power = ltv350qv_set_power, 227 }; 228 229 static int ltv350qv_probe(struct spi_device *spi) 230 { 231 struct ltv350qv *lcd; 232 struct lcd_device *ld; 233 int ret; 234 235 lcd = devm_kzalloc(&spi->dev, sizeof(struct ltv350qv), GFP_KERNEL); 236 if (!lcd) 237 return -ENOMEM; 238 239 lcd->spi = spi; 240 lcd->power = FB_BLANK_POWERDOWN; 241 lcd->buffer = devm_kzalloc(&spi->dev, 8, GFP_KERNEL); 242 if (!lcd->buffer) 243 return -ENOMEM; 244 245 ld = devm_lcd_device_register(&spi->dev, "ltv350qv", &spi->dev, lcd, 246 <v_ops); 247 if (IS_ERR(ld)) 248 return PTR_ERR(ld); 249 250 lcd->ld = ld; 251 252 ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK); 253 if (ret) 254 return ret; 255 256 spi_set_drvdata(spi, lcd); 257 258 return 0; 259 } 260 261 static int ltv350qv_remove(struct spi_device *spi) 262 { 263 struct ltv350qv *lcd = spi_get_drvdata(spi); 264 265 ltv350qv_power(lcd, FB_BLANK_POWERDOWN); 266 return 0; 267 } 268 269 #ifdef CONFIG_PM_SLEEP 270 static int ltv350qv_suspend(struct device *dev) 271 { 272 struct ltv350qv *lcd = dev_get_drvdata(dev); 273 274 return ltv350qv_power(lcd, FB_BLANK_POWERDOWN); 275 } 276 277 static int ltv350qv_resume(struct device *dev) 278 { 279 struct ltv350qv *lcd = dev_get_drvdata(dev); 280 281 return ltv350qv_power(lcd, FB_BLANK_UNBLANK); 282 } 283 #endif 284 285 static SIMPLE_DEV_PM_OPS(ltv350qv_pm_ops, ltv350qv_suspend, ltv350qv_resume); 286 287 /* Power down all displays on reboot, poweroff or halt */ 288 static void ltv350qv_shutdown(struct spi_device *spi) 289 { 290 struct ltv350qv *lcd = spi_get_drvdata(spi); 291 292 ltv350qv_power(lcd, FB_BLANK_POWERDOWN); 293 } 294 295 static struct spi_driver ltv350qv_driver = { 296 .driver = { 297 .name = "ltv350qv", 298 .pm = <v350qv_pm_ops, 299 }, 300 301 .probe = ltv350qv_probe, 302 .remove = ltv350qv_remove, 303 .shutdown = ltv350qv_shutdown, 304 }; 305 306 module_spi_driver(ltv350qv_driver); 307 308 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)"); 309 MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver"); 310 MODULE_LICENSE("GPL"); 311 MODULE_ALIAS("spi:ltv350qv"); 312