ltv350qv.c 7.6 KB

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