1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Power control for Samsung LTV350QV Quarter VGA LCD Panel 4 * 5 * Copyright (C) 2006, 2007 Atmel Corporation 6 */ 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 20 struct 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 the 29 * LTV350QV-F04 data sheet from Samsung. The register definitions are 30 * taken from the S6F2002 command list also from Samsung. Both 31 * documents are distributed with the AVR32 Linux BSP CD from Atmel. 32 * 33 * There's still some voodoo going on here, but it's a lot better than 34 * in the first incarnation of the driver where all we had was the raw 35 * numbers from the initialization sequence. 36 */ 37 static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val) 38 { 39 struct spi_message msg; 40 struct spi_transfer index_xfer = { 41 .len = 3, 42 .cs_change = 1, 43 }; 44 struct spi_transfer value_xfer = { 45 .len = 3, 46 }; 47 48 spi_message_init(&msg); 49 50 /* register index */ 51 lcd->buffer[0] = LTV_OPC_INDEX; 52 lcd->buffer[1] = 0x00; 53 lcd->buffer[2] = reg & 0x7f; 54 index_xfer.tx_buf = lcd->buffer; 55 spi_message_add_tail(&index_xfer, &msg); 56 57 /* register value */ 58 lcd->buffer[4] = LTV_OPC_DATA; 59 lcd->buffer[5] = val >> 8; 60 lcd->buffer[6] = val; 61 value_xfer.tx_buf = lcd->buffer + 4; 62 spi_message_add_tail(&value_xfer, &msg); 63 64 return spi_sync(lcd->spi, &msg); 65 } 66 67 /* The comments are taken straight from the data sheet */ 68 static int ltv350qv_power_on(struct ltv350qv *lcd) 69 { 70 int ret; 71 72 /* Power On Reset Display off State */ 73 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000)) 74 goto err; 75 usleep_range(15000, 16000); 76 77 /* Power Setting Function 1 */ 78 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE)) 79 goto err; 80 if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE)) 81 goto err_power1; 82 83 /* Power Setting Function 2 */ 84 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 85 LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5) 86 | LTV_SUPPLY_CURRENT(5))) 87 goto err_power2; 88 89 msleep(55); 90 91 /* Instruction Setting */ 92 ret = ltv350qv_write_reg(lcd, LTV_IFCTL, 93 LTV_NMD | LTV_REV | LTV_NL(0x1d)); 94 ret |= ltv350qv_write_reg(lcd, LTV_DATACTL, 95 LTV_DS_SAME | LTV_CHS_480 96 | LTV_DF_RGB | LTV_RGB_BGR); 97 ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE, 98 LTV_VSPL_ACTIVE_LOW 99 | LTV_HSPL_ACTIVE_LOW 100 | LTV_DPL_SAMPLE_RISING 101 | LTV_EPL_ACTIVE_LOW 102 | LTV_SS_RIGHT_TO_LEFT); 103 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3)); 104 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2, 105 LTV_NW_INV_1LINE | LTV_FWI(3)); 106 ret |= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a); 107 ret |= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021); 108 ret |= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) | LTV_EQ(0)); 109 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103); 110 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301); 111 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f); 112 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f); 113 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707); 114 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307); 115 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707); 116 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000); 117 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004); 118 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000); 119 if (ret) 120 goto err_settings; 121 122 /* Wait more than 2 frames */ 123 msleep(20); 124 125 /* Display On Sequence */ 126 ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1, 127 LTV_VCOM_DISABLE | LTV_VCOMOUT_ENABLE 128 | LTV_POWER_ON | LTV_DRIVE_CURRENT(5) 129 | LTV_SUPPLY_CURRENT(5)); 130 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2, 131 LTV_NW_INV_1LINE | LTV_DSC | LTV_FWI(3)); 132 if (ret) 133 goto err_disp_on; 134 135 /* Display should now be ON. Phew. */ 136 return 0; 137 138 err_disp_on: 139 /* 140 * Try to recover. Error handling probably isn't very useful 141 * at this point, just make a best effort to switch the panel 142 * off. 143 */ 144 ltv350qv_write_reg(lcd, LTV_PWRCTL1, 145 LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5) 146 | LTV_SUPPLY_CURRENT(5)); 147 ltv350qv_write_reg(lcd, LTV_GATECTL2, 148 LTV_NW_INV_1LINE | LTV_FWI(3)); 149 err_settings: 150 err_power2: 151 err_power1: 152 ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000); 153 usleep_range(1000, 1100); 154 err: 155 ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE); 156 return -EIO; 157 } 158 159 static int ltv350qv_power_off(struct ltv350qv *lcd) 160 { 161 int ret; 162 163 /* Display Off Sequence */ 164 ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1, 165 LTV_VCOM_DISABLE 166 | LTV_DRIVE_CURRENT(5) 167 | LTV_SUPPLY_CURRENT(5)); 168 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2, 169 LTV_NW_INV_1LINE | LTV_FWI(3)); 170 171 /* Power down setting 1 */ 172 ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000); 173 174 /* Wait at least 1 ms */ 175 usleep_range(1000, 1100); 176 177 /* Power down setting 2 */ 178 ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE); 179 180 /* 181 * No point in trying to recover here. If we can't switch the 182 * panel off, what are we supposed to do other than inform the 183 * user about the failure? 184 */ 185 if (ret) 186 return -EIO; 187 188 /* Display power should now be OFF */ 189 return 0; 190 } 191 192 static int ltv350qv_power(struct ltv350qv *lcd, int power) 193 { 194 int ret = 0; 195 196 if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power)) 197 ret = ltv350qv_power_on(lcd); 198 else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power)) 199 ret = ltv350qv_power_off(lcd); 200 201 if (!ret) 202 lcd->power = power; 203 204 return ret; 205 } 206 207 static int ltv350qv_set_power(struct lcd_device *ld, int power) 208 { 209 struct ltv350qv *lcd = lcd_get_data(ld); 210 211 return ltv350qv_power(lcd, power); 212 } 213 214 static int ltv350qv_get_power(struct lcd_device *ld) 215 { 216 struct ltv350qv *lcd = lcd_get_data(ld); 217 218 return lcd->power; 219 } 220 221 static struct lcd_ops ltv_ops = { 222 .get_power = ltv350qv_get_power, 223 .set_power = ltv350qv_set_power, 224 }; 225 226 static int ltv350qv_probe(struct spi_device *spi) 227 { 228 struct ltv350qv *lcd; 229 struct lcd_device *ld; 230 int ret; 231 232 lcd = devm_kzalloc(&spi->dev, sizeof(struct ltv350qv), GFP_KERNEL); 233 if (!lcd) 234 return -ENOMEM; 235 236 lcd->spi = spi; 237 lcd->power = FB_BLANK_POWERDOWN; 238 lcd->buffer = devm_kzalloc(&spi->dev, 8, GFP_KERNEL); 239 if (!lcd->buffer) 240 return -ENOMEM; 241 242 ld = devm_lcd_device_register(&spi->dev, "ltv350qv", &spi->dev, lcd, 243 <v_ops); 244 if (IS_ERR(ld)) 245 return PTR_ERR(ld); 246 247 lcd->ld = ld; 248 249 ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK); 250 if (ret) 251 return ret; 252 253 spi_set_drvdata(spi, lcd); 254 255 return 0; 256 } 257 258 static void ltv350qv_remove(struct spi_device *spi) 259 { 260 struct ltv350qv *lcd = spi_get_drvdata(spi); 261 262 ltv350qv_power(lcd, FB_BLANK_POWERDOWN); 263 } 264 265 #ifdef CONFIG_PM_SLEEP 266 static int ltv350qv_suspend(struct device *dev) 267 { 268 struct ltv350qv *lcd = dev_get_drvdata(dev); 269 270 return ltv350qv_power(lcd, FB_BLANK_POWERDOWN); 271 } 272 273 static int ltv350qv_resume(struct device *dev) 274 { 275 struct ltv350qv *lcd = dev_get_drvdata(dev); 276 277 return ltv350qv_power(lcd, FB_BLANK_UNBLANK); 278 } 279 #endif 280 281 static SIMPLE_DEV_PM_OPS(ltv350qv_pm_ops, ltv350qv_suspend, ltv350qv_resume); 282 283 /* Power down all displays on reboot, poweroff or halt */ 284 static void ltv350qv_shutdown(struct spi_device *spi) 285 { 286 struct ltv350qv *lcd = spi_get_drvdata(spi); 287 288 ltv350qv_power(lcd, FB_BLANK_POWERDOWN); 289 } 290 291 static struct spi_driver ltv350qv_driver = { 292 .driver = { 293 .name = "ltv350qv", 294 .pm = <v350qv_pm_ops, 295 }, 296 297 .probe = ltv350qv_probe, 298 .remove = ltv350qv_remove, 299 .shutdown = ltv350qv_shutdown, 300 }; 301 302 module_spi_driver(ltv350qv_driver); 303 304 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)"); 305 MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver"); 306 MODULE_LICENSE("GPL"); 307 MODULE_ALIAS("spi:ltv350qv"); 308