vc4_dpi.c 9.7 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Copyright (C) 2016 Broadcom Limited
  4. */
  5. /**
  6. * DOC: VC4 DPI module
  7. *
  8. * The VC4 DPI hardware supports MIPI DPI type 4 and Nokia ViSSI
  9. * signals. On BCM2835, these can be routed out to GPIO0-27 with the
  10. * ALT2 function.
  11. */
  12. #include <drm/drm_atomic_helper.h>
  13. #include <drm/drm_bridge.h>
  14. #include <drm/drm_edid.h>
  15. #include <drm/drm_of.h>
  16. #include <drm/drm_panel.h>
  17. #include <drm/drm_probe_helper.h>
  18. #include <drm/drm_simple_kms_helper.h>
  19. #include <linux/clk.h>
  20. #include <linux/component.h>
  21. #include <linux/of_graph.h>
  22. #include <linux/of_platform.h>
  23. #include "vc4_drv.h"
  24. #include "vc4_regs.h"
  25. #define DPI_C 0x00
  26. # define DPI_OUTPUT_ENABLE_MODE BIT(16)
  27. /* The order field takes the incoming 24 bit RGB from the pixel valve
  28. * and shuffles the 3 channels.
  29. */
  30. # define DPI_ORDER_MASK VC4_MASK(15, 14)
  31. # define DPI_ORDER_SHIFT 14
  32. # define DPI_ORDER_RGB 0
  33. # define DPI_ORDER_BGR 1
  34. # define DPI_ORDER_GRB 2
  35. # define DPI_ORDER_BRG 3
  36. /* The format field takes the ORDER-shuffled pixel valve data and
  37. * formats it onto the output lines.
  38. */
  39. # define DPI_FORMAT_MASK VC4_MASK(13, 11)
  40. # define DPI_FORMAT_SHIFT 11
  41. /* This define is named in the hardware, but actually just outputs 0. */
  42. # define DPI_FORMAT_9BIT_666_RGB 0
  43. /* Outputs 00000000rrrrrggggggbbbbb */
  44. # define DPI_FORMAT_16BIT_565_RGB_1 1
  45. /* Outputs 000rrrrr00gggggg000bbbbb */
  46. # define DPI_FORMAT_16BIT_565_RGB_2 2
  47. /* Outputs 00rrrrr000gggggg00bbbbb0 */
  48. # define DPI_FORMAT_16BIT_565_RGB_3 3
  49. /* Outputs 000000rrrrrrggggggbbbbbb */
  50. # define DPI_FORMAT_18BIT_666_RGB_1 4
  51. /* Outputs 00rrrrrr00gggggg00bbbbbb */
  52. # define DPI_FORMAT_18BIT_666_RGB_2 5
  53. /* Outputs rrrrrrrrggggggggbbbbbbbb */
  54. # define DPI_FORMAT_24BIT_888_RGB 6
  55. /* Reverses the polarity of the corresponding signal */
  56. # define DPI_PIXEL_CLK_INVERT BIT(10)
  57. # define DPI_HSYNC_INVERT BIT(9)
  58. # define DPI_VSYNC_INVERT BIT(8)
  59. # define DPI_OUTPUT_ENABLE_INVERT BIT(7)
  60. /* Outputs the signal the falling clock edge instead of rising. */
  61. # define DPI_HSYNC_NEGATE BIT(6)
  62. # define DPI_VSYNC_NEGATE BIT(5)
  63. # define DPI_OUTPUT_ENABLE_NEGATE BIT(4)
  64. /* Disables the signal */
  65. # define DPI_HSYNC_DISABLE BIT(3)
  66. # define DPI_VSYNC_DISABLE BIT(2)
  67. # define DPI_OUTPUT_ENABLE_DISABLE BIT(1)
  68. /* Power gate to the device, full reset at 0 -> 1 transition */
  69. # define DPI_ENABLE BIT(0)
  70. /* All other registers besides DPI_C return the ID */
  71. #define DPI_ID 0x04
  72. # define DPI_ID_VALUE 0x00647069
  73. /* General DPI hardware state. */
  74. struct vc4_dpi {
  75. struct platform_device *pdev;
  76. struct drm_encoder *encoder;
  77. void __iomem *regs;
  78. struct clk *pixel_clock;
  79. struct clk *core_clock;
  80. struct debugfs_regset32 regset;
  81. };
  82. #define DPI_READ(offset) readl(dpi->regs + (offset))
  83. #define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset))
  84. /* VC4 DPI encoder KMS struct */
  85. struct vc4_dpi_encoder {
  86. struct vc4_encoder base;
  87. struct vc4_dpi *dpi;
  88. };
  89. static inline struct vc4_dpi_encoder *
  90. to_vc4_dpi_encoder(struct drm_encoder *encoder)
  91. {
  92. return container_of(encoder, struct vc4_dpi_encoder, base.base);
  93. }
  94. static const struct debugfs_reg32 dpi_regs[] = {
  95. VC4_REG32(DPI_C),
  96. VC4_REG32(DPI_ID),
  97. };
  98. static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
  99. {
  100. struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
  101. struct vc4_dpi *dpi = vc4_encoder->dpi;
  102. clk_disable_unprepare(dpi->pixel_clock);
  103. }
  104. static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
  105. {
  106. struct drm_device *dev = encoder->dev;
  107. struct drm_display_mode *mode = &encoder->crtc->mode;
  108. struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
  109. struct vc4_dpi *dpi = vc4_encoder->dpi;
  110. struct drm_connector_list_iter conn_iter;
  111. struct drm_connector *connector = NULL, *connector_scan;
  112. u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
  113. int ret;
  114. /* Look up the connector attached to DPI so we can get the
  115. * bus_format. Ideally the bridge would tell us the
  116. * bus_format we want, but it doesn't yet, so assume that it's
  117. * uniform throughout the bridge chain.
  118. */
  119. drm_connector_list_iter_begin(dev, &conn_iter);
  120. drm_for_each_connector_iter(connector_scan, &conn_iter) {
  121. if (connector_scan->encoder == encoder) {
  122. connector = connector_scan;
  123. break;
  124. }
  125. }
  126. drm_connector_list_iter_end(&conn_iter);
  127. if (connector && connector->display_info.num_bus_formats) {
  128. u32 bus_format = connector->display_info.bus_formats[0];
  129. switch (bus_format) {
  130. case MEDIA_BUS_FMT_RGB888_1X24:
  131. dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
  132. DPI_FORMAT);
  133. break;
  134. case MEDIA_BUS_FMT_BGR888_1X24:
  135. dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
  136. DPI_FORMAT);
  137. dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
  138. break;
  139. case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
  140. dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
  141. DPI_FORMAT);
  142. break;
  143. case MEDIA_BUS_FMT_RGB666_1X18:
  144. dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
  145. DPI_FORMAT);
  146. break;
  147. case MEDIA_BUS_FMT_RGB565_1X16:
  148. dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
  149. DPI_FORMAT);
  150. break;
  151. default:
  152. DRM_ERROR("Unknown media bus format %d\n", bus_format);
  153. break;
  154. }
  155. } else {
  156. /* Default to 24bit if no connector found. */
  157. dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT);
  158. }
  159. if (mode->flags & DRM_MODE_FLAG_NHSYNC)
  160. dpi_c |= DPI_HSYNC_INVERT;
  161. else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
  162. dpi_c |= DPI_HSYNC_DISABLE;
  163. if (mode->flags & DRM_MODE_FLAG_NVSYNC)
  164. dpi_c |= DPI_VSYNC_INVERT;
  165. else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
  166. dpi_c |= DPI_VSYNC_DISABLE;
  167. DPI_WRITE(DPI_C, dpi_c);
  168. ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
  169. if (ret)
  170. DRM_ERROR("Failed to set clock rate: %d\n", ret);
  171. ret = clk_prepare_enable(dpi->pixel_clock);
  172. if (ret)
  173. DRM_ERROR("Failed to set clock rate: %d\n", ret);
  174. }
  175. static enum drm_mode_status vc4_dpi_encoder_mode_valid(struct drm_encoder *encoder,
  176. const struct drm_display_mode *mode)
  177. {
  178. if (mode->flags & DRM_MODE_FLAG_INTERLACE)
  179. return MODE_NO_INTERLACE;
  180. return MODE_OK;
  181. }
  182. static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
  183. .disable = vc4_dpi_encoder_disable,
  184. .enable = vc4_dpi_encoder_enable,
  185. .mode_valid = vc4_dpi_encoder_mode_valid,
  186. };
  187. static const struct of_device_id vc4_dpi_dt_match[] = {
  188. { .compatible = "brcm,bcm2835-dpi", .data = NULL },
  189. {}
  190. };
  191. /* Sets up the next link in the display chain, whether it's a panel or
  192. * a bridge.
  193. */
  194. static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
  195. {
  196. struct device *dev = &dpi->pdev->dev;
  197. struct drm_panel *panel;
  198. struct drm_bridge *bridge;
  199. int ret;
  200. ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
  201. &panel, &bridge);
  202. if (ret) {
  203. /* If nothing was connected in the DT, that's not an
  204. * error.
  205. */
  206. if (ret == -ENODEV)
  207. return 0;
  208. else
  209. return ret;
  210. }
  211. if (panel)
  212. bridge = drm_panel_bridge_add_typed(panel,
  213. DRM_MODE_CONNECTOR_DPI);
  214. return drm_bridge_attach(dpi->encoder, bridge, NULL, 0);
  215. }
  216. static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
  217. {
  218. struct platform_device *pdev = to_platform_device(dev);
  219. struct drm_device *drm = dev_get_drvdata(master);
  220. struct vc4_dev *vc4 = to_vc4_dev(drm);
  221. struct vc4_dpi *dpi;
  222. struct vc4_dpi_encoder *vc4_dpi_encoder;
  223. int ret;
  224. dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL);
  225. if (!dpi)
  226. return -ENOMEM;
  227. vc4_dpi_encoder = devm_kzalloc(dev, sizeof(*vc4_dpi_encoder),
  228. GFP_KERNEL);
  229. if (!vc4_dpi_encoder)
  230. return -ENOMEM;
  231. vc4_dpi_encoder->base.type = VC4_ENCODER_TYPE_DPI;
  232. vc4_dpi_encoder->dpi = dpi;
  233. dpi->encoder = &vc4_dpi_encoder->base.base;
  234. dpi->pdev = pdev;
  235. dpi->regs = vc4_ioremap_regs(pdev, 0);
  236. if (IS_ERR(dpi->regs))
  237. return PTR_ERR(dpi->regs);
  238. dpi->regset.base = dpi->regs;
  239. dpi->regset.regs = dpi_regs;
  240. dpi->regset.nregs = ARRAY_SIZE(dpi_regs);
  241. if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
  242. dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
  243. DPI_READ(DPI_ID), DPI_ID_VALUE);
  244. return -ENODEV;
  245. }
  246. dpi->core_clock = devm_clk_get(dev, "core");
  247. if (IS_ERR(dpi->core_clock)) {
  248. ret = PTR_ERR(dpi->core_clock);
  249. if (ret != -EPROBE_DEFER)
  250. DRM_ERROR("Failed to get core clock: %d\n", ret);
  251. return ret;
  252. }
  253. dpi->pixel_clock = devm_clk_get(dev, "pixel");
  254. if (IS_ERR(dpi->pixel_clock)) {
  255. ret = PTR_ERR(dpi->pixel_clock);
  256. if (ret != -EPROBE_DEFER)
  257. DRM_ERROR("Failed to get pixel clock: %d\n", ret);
  258. return ret;
  259. }
  260. ret = clk_prepare_enable(dpi->core_clock);
  261. if (ret)
  262. DRM_ERROR("Failed to turn on core clock: %d\n", ret);
  263. drm_simple_encoder_init(drm, dpi->encoder, DRM_MODE_ENCODER_DPI);
  264. drm_encoder_helper_add(dpi->encoder, &vc4_dpi_encoder_helper_funcs);
  265. ret = vc4_dpi_init_bridge(dpi);
  266. if (ret)
  267. goto err_destroy_encoder;
  268. dev_set_drvdata(dev, dpi);
  269. vc4->dpi = dpi;
  270. vc4_debugfs_add_regset32(drm, "dpi_regs", &dpi->regset);
  271. return 0;
  272. err_destroy_encoder:
  273. drm_encoder_cleanup(dpi->encoder);
  274. clk_disable_unprepare(dpi->core_clock);
  275. return ret;
  276. }
  277. static void vc4_dpi_unbind(struct device *dev, struct device *master,
  278. void *data)
  279. {
  280. struct drm_device *drm = dev_get_drvdata(master);
  281. struct vc4_dev *vc4 = to_vc4_dev(drm);
  282. struct vc4_dpi *dpi = dev_get_drvdata(dev);
  283. drm_of_panel_bridge_remove(dev->of_node, 0, 0);
  284. drm_encoder_cleanup(dpi->encoder);
  285. clk_disable_unprepare(dpi->core_clock);
  286. vc4->dpi = NULL;
  287. }
  288. static const struct component_ops vc4_dpi_ops = {
  289. .bind = vc4_dpi_bind,
  290. .unbind = vc4_dpi_unbind,
  291. };
  292. static int vc4_dpi_dev_probe(struct platform_device *pdev)
  293. {
  294. return component_add(&pdev->dev, &vc4_dpi_ops);
  295. }
  296. static int vc4_dpi_dev_remove(struct platform_device *pdev)
  297. {
  298. component_del(&pdev->dev, &vc4_dpi_ops);
  299. return 0;
  300. }
  301. struct platform_driver vc4_dpi_driver = {
  302. .probe = vc4_dpi_dev_probe,
  303. .remove = vc4_dpi_dev_remove,
  304. .driver = {
  305. .name = "vc4_dpi",
  306. .of_match_table = vc4_dpi_dt_match,
  307. },
  308. };