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. 31 * 32 * There's still some voodoo going on here, but it's a lot better than 33 * in the first incarnation of the driver where all we had was the raw 34 * numbers from the initialization sequence. 35 */ 36 static 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 */ 67 static 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_480 95 | LTV_DF_RGB | LTV_RGB_BGR); 96 ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE, 97 LTV_VSPL_ACTIVE_LOW 98 | LTV_HSPL_ACTIVE_LOW 99 | LTV_DPL_SAMPLE_RISING 100 | LTV_EPL_ACTIVE_LOW 101 | 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_ENABLE 127 | 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; 136 137 err_disp_on: 138 /* 139 * Try to recover. Error handling probably isn't very useful 140 * at this point, just make a best effort to switch the panel 141 * 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)); 148 err_settings: 149 err_power2: 150 err_power1: 151 ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000); 152 usleep_range(1000, 1100); 153 err: 154 ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE); 155 return -EIO; 156 } 157 158 static 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_DISABLE 165 | 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 the 181 * panel off, what are we supposed to do other than inform the 182 * user about the failure? 183 */ 184 if (ret) 185 return -EIO; 186 187 /* Display power should now be OFF */ 188 return 0; 189 } 190 191 static 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 } 205 206 static 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 } 212 213 static int ltv350qv_get_power(struct lcd_device *ld) 214 { 215 struct ltv350qv *lcd = lcd_get_data(ld); 216 217 return lcd->power; 218 } 219 220 static struct lcd_ops ltv_ops = { 221 .get_power = ltv350qv_get_power, 222 .set_power = ltv350qv_set_power, 223 }; 224 225 static 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 } 256 257 static 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_SLEEP 265 static 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 } 271 272 static 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 #endif 279 280 static SIMPLE_DEV_PM_OPS(ltv350qv_pm_ops, ltv350qv_suspend, ltv350qv_resume); 281 282 /* Power down all displays on reboot, poweroff or halt */ 283 static 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 } 289 290 static 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 }; 300 301 module_spi_driver(ltv350qv_driver); 302 303 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)"); 304 MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver"); 305 MODULE_LICENSE("GPL"); 306 MODULE_ALIAS("spi:ltv350qv"); 307