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/spi/spi.h> 17 18 #include "ltv350qv.h" 19 20 #define POWER_IS_ON(pwr) ((pwr) <= FB_BLANK_NORMAL) 21 22 struct ltv350qv { 23 struct spi_device *spi; 24 u8 *buffer; 25 int power; 26 struct lcd_device *ld; 27 }; 28 29 /* 30 * The power-on and power-off sequences are taken from the 31 * LTV350QV-F04 data sheet from Samsung. The register definitions are 32 * taken from the S6F2002 command list also from Samsung. Both 33 * documents are distributed with the AVR32 Linux BSP CD from Atmel. 34 * 35 * There's still some voodoo going on here, but it's a lot better than 36 * in the first incarnation of the driver where all we had was the raw 37 * numbers from the initialization sequence. 38 */ 39 static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val) 40 { 41 struct spi_message msg; 42 struct spi_transfer index_xfer = { 43 .len = 3, 44 .cs_change = 1, 45 }; 46 struct spi_transfer value_xfer = { 47 .len = 3, 48 }; 49 50 spi_message_init(&msg); 51 52 /* register index */ 53 lcd->buffer[0] = LTV_OPC_INDEX; 54 lcd->buffer[1] = 0x00; 55 lcd->buffer[2] = reg & 0x7f; 56 index_xfer.tx_buf = lcd->buffer; 57 spi_message_add_tail(&index_xfer, &msg); 58 59 /* register value */ 60 lcd->buffer[4] = LTV_OPC_DATA; 61 lcd->buffer[5] = val >> 8; 62 lcd->buffer[6] = val; 63 value_xfer.tx_buf = lcd->buffer + 4; 64 spi_message_add_tail(&value_xfer, &msg); 65 66 return spi_sync(lcd->spi, &msg); 67 } 68 69 /* The comments are taken straight from the data sheet */ 70 static int ltv350qv_power_on(struct ltv350qv *lcd) 71 { 72 int ret; 73 74 /* Power On Reset Display off State */ 75 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000)) 76 goto err; 77 msleep(15); 78 79 /* Power Setting Function 1 */ 80 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE)) 81 goto err; 82 if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE)) 83 goto err_power1; 84 85 /* Power Setting Function 2 */ 86 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 87 LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5) 88 | LTV_SUPPLY_CURRENT(5))) 89 goto err_power2; 90 91 msleep(55); 92 93 /* Instruction Setting */ 94 ret = ltv350qv_write_reg(lcd, LTV_IFCTL, 95 LTV_NMD | LTV_REV | LTV_NL(0x1d)); 96 ret |= ltv350qv_write_reg(lcd, LTV_DATACTL, 97 LTV_DS_SAME | LTV_CHS_480 98 | LTV_DF_RGB | LTV_RGB_BGR); 99 ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE, 100 LTV_VSPL_ACTIVE_LOW 101 | LTV_HSPL_ACTIVE_LOW 102 | LTV_DPL_SAMPLE_RISING 103 | LTV_EPL_ACTIVE_LOW 104 | LTV_SS_RIGHT_TO_LEFT); 105 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3)); 106 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2, 107 LTV_NW_INV_1LINE | LTV_FWI(3)); 108 ret |= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a); 109 ret |= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021); 110 ret |= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) | LTV_EQ(0)); 111 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103); 112 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301); 113 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f); 114 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f); 115 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707); 116 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307); 117 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707); 118 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000); 119 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004); 120 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000); 121 if (ret) 122 goto err_settings; 123 124 /* Wait more than 2 frames */ 125 msleep(20); 126 127 /* Display On Sequence */ 128 ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1, 129 LTV_VCOM_DISABLE | LTV_VCOMOUT_ENABLE 130 | LTV_POWER_ON | LTV_DRIVE_CURRENT(5) 131 | LTV_SUPPLY_CURRENT(5)); 132 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2, 133 LTV_NW_INV_1LINE | LTV_DSC | LTV_FWI(3)); 134 if (ret) 135 goto err_disp_on; 136 137 /* Display should now be ON. Phew. */ 138 return 0; 139 140 err_disp_on: 141 /* 142 * Try to recover. Error handling probably isn't very useful 143 * at this point, just make a best effort to switch the panel 144 * off. 145 */ 146 ltv350qv_write_reg(lcd, LTV_PWRCTL1, 147 LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5) 148 | LTV_SUPPLY_CURRENT(5)); 149 ltv350qv_write_reg(lcd, LTV_GATECTL2, 150 LTV_NW_INV_1LINE | LTV_FWI(3)); 151 err_settings: 152 err_power2: 153 err_power1: 154 ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000); 155 msleep(1); 156 err: 157 ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE); 158 return -EIO; 159 } 160 161 static int ltv350qv_power_off(struct ltv350qv *lcd) 162 { 163 int ret; 164 165 /* Display Off Sequence */ 166 ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1, 167 LTV_VCOM_DISABLE 168 | LTV_DRIVE_CURRENT(5) 169 | LTV_SUPPLY_CURRENT(5)); 170 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2, 171 LTV_NW_INV_1LINE | LTV_FWI(3)); 172 173 /* Power down setting 1 */ 174 ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000); 175 176 /* Wait at least 1 ms */ 177 msleep(1); 178 179 /* Power down setting 2 */ 180 ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE); 181 182 /* 183 * No point in trying to recover here. If we can't switch the 184 * panel off, what are we supposed to do other than inform the 185 * user about the failure? 186 */ 187 if (ret) 188 return -EIO; 189 190 /* Display power should now be OFF */ 191 return 0; 192 } 193 194 static int ltv350qv_power(struct ltv350qv *lcd, int power) 195 { 196 int ret = 0; 197 198 if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power)) 199 ret = ltv350qv_power_on(lcd); 200 else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power)) 201 ret = ltv350qv_power_off(lcd); 202 203 if (!ret) 204 lcd->power = power; 205 206 return ret; 207 } 208 209 static int ltv350qv_set_power(struct lcd_device *ld, int power) 210 { 211 struct ltv350qv *lcd = lcd_get_data(ld); 212 213 return ltv350qv_power(lcd, power); 214 } 215 216 static int ltv350qv_get_power(struct lcd_device *ld) 217 { 218 struct ltv350qv *lcd = lcd_get_data(ld); 219 220 return lcd->power; 221 } 222 223 static struct lcd_ops ltv_ops = { 224 .get_power = ltv350qv_get_power, 225 .set_power = ltv350qv_set_power, 226 }; 227 228 static int __devinit ltv350qv_probe(struct spi_device *spi) 229 { 230 struct ltv350qv *lcd; 231 struct lcd_device *ld; 232 int ret; 233 234 lcd = kzalloc(sizeof(struct ltv350qv), GFP_KERNEL); 235 if (!lcd) 236 return -ENOMEM; 237 238 lcd->spi = spi; 239 lcd->power = FB_BLANK_POWERDOWN; 240 lcd->buffer = kzalloc(8, GFP_KERNEL); 241 242 ld = lcd_device_register("ltv350qv", &spi->dev, lcd, <v_ops); 243 if (IS_ERR(ld)) { 244 ret = PTR_ERR(ld); 245 goto out_free_lcd; 246 } 247 lcd->ld = ld; 248 249 ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK); 250 if (ret) 251 goto out_unregister; 252 253 dev_set_drvdata(&spi->dev, lcd); 254 255 return 0; 256 257 out_unregister: 258 lcd_device_unregister(ld); 259 out_free_lcd: 260 kfree(lcd); 261 return ret; 262 } 263 264 static int __devexit ltv350qv_remove(struct spi_device *spi) 265 { 266 struct ltv350qv *lcd = dev_get_drvdata(&spi->dev); 267 268 ltv350qv_power(lcd, FB_BLANK_POWERDOWN); 269 lcd_device_unregister(lcd->ld); 270 kfree(lcd); 271 272 return 0; 273 } 274 275 #ifdef CONFIG_PM 276 static int ltv350qv_suspend(struct spi_device *spi, pm_message_t state) 277 { 278 struct ltv350qv *lcd = dev_get_drvdata(&spi->dev); 279 280 return ltv350qv_power(lcd, FB_BLANK_POWERDOWN); 281 } 282 283 static int ltv350qv_resume(struct spi_device *spi) 284 { 285 struct ltv350qv *lcd = dev_get_drvdata(&spi->dev); 286 287 return ltv350qv_power(lcd, FB_BLANK_UNBLANK); 288 } 289 #else 290 #define ltv350qv_suspend NULL 291 #define ltv350qv_resume NULL 292 #endif 293 294 /* Power down all displays on reboot, poweroff or halt */ 295 static void ltv350qv_shutdown(struct spi_device *spi) 296 { 297 struct ltv350qv *lcd = dev_get_drvdata(&spi->dev); 298 299 ltv350qv_power(lcd, FB_BLANK_POWERDOWN); 300 } 301 302 static struct spi_driver ltv350qv_driver = { 303 .driver = { 304 .name = "ltv350qv", 305 .bus = &spi_bus_type, 306 .owner = THIS_MODULE, 307 }, 308 309 .probe = ltv350qv_probe, 310 .remove = __devexit_p(ltv350qv_remove), 311 .shutdown = ltv350qv_shutdown, 312 .suspend = ltv350qv_suspend, 313 .resume = ltv350qv_resume, 314 }; 315 316 static int __init ltv350qv_init(void) 317 { 318 return spi_register_driver(<v350qv_driver); 319 } 320 321 static void __exit ltv350qv_exit(void) 322 { 323 spi_unregister_driver(<v350qv_driver); 324 } 325 module_init(ltv350qv_init); 326 module_exit(ltv350qv_exit); 327 328 MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>"); 329 MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver"); 330 MODULE_LICENSE("GPL"); 331 MODULE_ALIAS("spi:ltv350qv"); 332