1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2016 Broadcom Limited 4 */ 5 6 /** 7 * DOC: VC4 DPI module 8 * 9 * The VC4 DPI hardware supports MIPI DPI type 4 and Nokia ViSSI 10 * signals. On BCM2835, these can be routed out to GPIO0-27 with the 11 * ALT2 function. 12 */ 13 14 #include <drm/drm_atomic_helper.h> 15 #include <drm/drm_bridge.h> 16 #include <drm/drm_drv.h> 17 #include <drm/drm_edid.h> 18 #include <drm/drm_of.h> 19 #include <drm/drm_panel.h> 20 #include <drm/drm_probe_helper.h> 21 #include <drm/drm_simple_kms_helper.h> 22 #include <linux/clk.h> 23 #include <linux/component.h> 24 #include <linux/media-bus-format.h> 25 #include <linux/of_graph.h> 26 #include <linux/of_platform.h> 27 #include "vc4_drv.h" 28 #include "vc4_regs.h" 29 30 #define DPI_C 0x00 31 # define DPI_OUTPUT_ENABLE_MODE BIT(16) 32 33 /* The order field takes the incoming 24 bit RGB from the pixel valve 34 * and shuffles the 3 channels. 35 */ 36 # define DPI_ORDER_MASK VC4_MASK(15, 14) 37 # define DPI_ORDER_SHIFT 14 38 # define DPI_ORDER_RGB 0 39 # define DPI_ORDER_BGR 1 40 # define DPI_ORDER_GRB 2 41 # define DPI_ORDER_BRG 3 42 43 /* The format field takes the ORDER-shuffled pixel valve data and 44 * formats it onto the output lines. 45 */ 46 # define DPI_FORMAT_MASK VC4_MASK(13, 11) 47 # define DPI_FORMAT_SHIFT 11 48 /* This define is named in the hardware, but actually just outputs 0. */ 49 # define DPI_FORMAT_9BIT_666_RGB 0 50 /* Outputs 00000000rrrrrggggggbbbbb */ 51 # define DPI_FORMAT_16BIT_565_RGB_1 1 52 /* Outputs 000rrrrr00gggggg000bbbbb */ 53 # define DPI_FORMAT_16BIT_565_RGB_2 2 54 /* Outputs 00rrrrr000gggggg00bbbbb0 */ 55 # define DPI_FORMAT_16BIT_565_RGB_3 3 56 /* Outputs 000000rrrrrrggggggbbbbbb */ 57 # define DPI_FORMAT_18BIT_666_RGB_1 4 58 /* Outputs 00rrrrrr00gggggg00bbbbbb */ 59 # define DPI_FORMAT_18BIT_666_RGB_2 5 60 /* Outputs rrrrrrrrggggggggbbbbbbbb */ 61 # define DPI_FORMAT_24BIT_888_RGB 6 62 63 /* Reverses the polarity of the corresponding signal */ 64 # define DPI_PIXEL_CLK_INVERT BIT(10) 65 # define DPI_HSYNC_INVERT BIT(9) 66 # define DPI_VSYNC_INVERT BIT(8) 67 # define DPI_OUTPUT_ENABLE_INVERT BIT(7) 68 69 /* Outputs the signal the falling clock edge instead of rising. */ 70 # define DPI_HSYNC_NEGATE BIT(6) 71 # define DPI_VSYNC_NEGATE BIT(5) 72 # define DPI_OUTPUT_ENABLE_NEGATE BIT(4) 73 74 /* Disables the signal */ 75 # define DPI_HSYNC_DISABLE BIT(3) 76 # define DPI_VSYNC_DISABLE BIT(2) 77 # define DPI_OUTPUT_ENABLE_DISABLE BIT(1) 78 79 /* Power gate to the device, full reset at 0 -> 1 transition */ 80 # define DPI_ENABLE BIT(0) 81 82 /* All other registers besides DPI_C return the ID */ 83 #define DPI_ID 0x04 84 # define DPI_ID_VALUE 0x00647069 85 86 /* General DPI hardware state. */ 87 struct vc4_dpi { 88 struct vc4_encoder encoder; 89 90 struct platform_device *pdev; 91 92 void __iomem *regs; 93 94 struct clk *pixel_clock; 95 struct clk *core_clock; 96 97 struct debugfs_regset32 regset; 98 }; 99 100 #define to_vc4_dpi(_encoder) \ 101 container_of_const(_encoder, struct vc4_dpi, encoder.base) 102 103 #define DPI_READ(offset) \ 104 ({ \ 105 kunit_fail_current_test("Accessing a register in a unit test!\n"); \ 106 readl(dpi->regs + (offset)); \ 107 }) 108 109 #define DPI_WRITE(offset, val) \ 110 do { \ 111 kunit_fail_current_test("Accessing a register in a unit test!\n"); \ 112 writel(val, dpi->regs + (offset)); \ 113 } while (0) 114 115 static const struct debugfs_reg32 dpi_regs[] = { 116 VC4_REG32(DPI_C), 117 VC4_REG32(DPI_ID), 118 }; 119 120 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder) 121 { 122 struct drm_device *dev = encoder->dev; 123 struct vc4_dpi *dpi = to_vc4_dpi(encoder); 124 int idx; 125 126 if (!drm_dev_enter(dev, &idx)) 127 return; 128 129 clk_disable_unprepare(dpi->pixel_clock); 130 131 drm_dev_exit(idx); 132 } 133 134 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder) 135 { 136 struct drm_device *dev = encoder->dev; 137 struct drm_display_mode *mode = &encoder->crtc->mode; 138 struct vc4_dpi *dpi = to_vc4_dpi(encoder); 139 struct drm_connector_list_iter conn_iter; 140 struct drm_connector *connector = NULL, *connector_scan; 141 u32 dpi_c = DPI_ENABLE; 142 int idx; 143 int ret; 144 145 /* Look up the connector attached to DPI so we can get the 146 * bus_format. Ideally the bridge would tell us the 147 * bus_format we want, but it doesn't yet, so assume that it's 148 * uniform throughout the bridge chain. 149 */ 150 drm_connector_list_iter_begin(dev, &conn_iter); 151 drm_for_each_connector_iter(connector_scan, &conn_iter) { 152 if (connector_scan->encoder == encoder) { 153 connector = connector_scan; 154 break; 155 } 156 } 157 drm_connector_list_iter_end(&conn_iter); 158 159 /* Default to 18bit if no connector or format found. */ 160 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1, DPI_FORMAT); 161 162 if (connector) { 163 if (connector->display_info.num_bus_formats) { 164 u32 bus_format = connector->display_info.bus_formats[0]; 165 166 dpi_c &= ~DPI_FORMAT_MASK; 167 168 switch (bus_format) { 169 case MEDIA_BUS_FMT_RGB888_1X24: 170 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, 171 DPI_FORMAT); 172 break; 173 case MEDIA_BUS_FMT_BGR888_1X24: 174 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, 175 DPI_FORMAT); 176 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, 177 DPI_ORDER); 178 break; 179 case MEDIA_BUS_FMT_BGR666_1X24_CPADHI: 180 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER); 181 fallthrough; 182 case MEDIA_BUS_FMT_RGB666_1X24_CPADHI: 183 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2, 184 DPI_FORMAT); 185 break; 186 case MEDIA_BUS_FMT_BGR666_1X18: 187 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER); 188 fallthrough; 189 case MEDIA_BUS_FMT_RGB666_1X18: 190 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1, 191 DPI_FORMAT); 192 break; 193 case MEDIA_BUS_FMT_RGB565_1X16: 194 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_1, 195 DPI_FORMAT); 196 break; 197 case MEDIA_BUS_FMT_RGB565_1X24_CPADHI: 198 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_2, 199 DPI_FORMAT); 200 break; 201 default: 202 DRM_ERROR("Unknown media bus format %d\n", 203 bus_format); 204 break; 205 } 206 } 207 208 if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE) 209 dpi_c |= DPI_PIXEL_CLK_INVERT; 210 211 if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW) 212 dpi_c |= DPI_OUTPUT_ENABLE_INVERT; 213 } 214 215 if (mode->flags & DRM_MODE_FLAG_CSYNC) { 216 if (mode->flags & DRM_MODE_FLAG_NCSYNC) 217 dpi_c |= DPI_OUTPUT_ENABLE_INVERT; 218 } else { 219 dpi_c |= DPI_OUTPUT_ENABLE_MODE; 220 221 if (mode->flags & DRM_MODE_FLAG_NHSYNC) 222 dpi_c |= DPI_HSYNC_INVERT; 223 else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC)) 224 dpi_c |= DPI_HSYNC_DISABLE; 225 226 if (mode->flags & DRM_MODE_FLAG_NVSYNC) 227 dpi_c |= DPI_VSYNC_INVERT; 228 else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC)) 229 dpi_c |= DPI_VSYNC_DISABLE; 230 } 231 232 if (!drm_dev_enter(dev, &idx)) 233 return; 234 235 DPI_WRITE(DPI_C, dpi_c); 236 237 ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000); 238 if (ret) 239 DRM_ERROR("Failed to set clock rate: %d\n", ret); 240 241 ret = clk_prepare_enable(dpi->pixel_clock); 242 if (ret) 243 DRM_ERROR("Failed to set clock rate: %d\n", ret); 244 245 drm_dev_exit(idx); 246 } 247 248 static enum drm_mode_status vc4_dpi_encoder_mode_valid(struct drm_encoder *encoder, 249 const struct drm_display_mode *mode) 250 { 251 if (mode->flags & DRM_MODE_FLAG_INTERLACE) 252 return MODE_NO_INTERLACE; 253 254 return MODE_OK; 255 } 256 257 static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = { 258 .disable = vc4_dpi_encoder_disable, 259 .enable = vc4_dpi_encoder_enable, 260 .mode_valid = vc4_dpi_encoder_mode_valid, 261 }; 262 263 static int vc4_dpi_late_register(struct drm_encoder *encoder) 264 { 265 struct drm_device *drm = encoder->dev; 266 struct vc4_dpi *dpi = to_vc4_dpi(encoder); 267 268 vc4_debugfs_add_regset32(drm, "dpi_regs", &dpi->regset); 269 270 return 0; 271 } 272 273 static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = { 274 .late_register = vc4_dpi_late_register, 275 }; 276 277 static const struct of_device_id vc4_dpi_dt_match[] = { 278 { .compatible = "brcm,bcm2835-dpi", .data = NULL }, 279 {} 280 }; 281 282 /* Sets up the next link in the display chain, whether it's a panel or 283 * a bridge. 284 */ 285 static int vc4_dpi_init_bridge(struct vc4_dpi *dpi) 286 { 287 struct drm_device *drm = dpi->encoder.base.dev; 288 struct device *dev = &dpi->pdev->dev; 289 struct drm_bridge *bridge; 290 291 bridge = drmm_of_get_bridge(drm, dev->of_node, 0, 0); 292 if (IS_ERR(bridge)) { 293 /* If nothing was connected in the DT, that's not an 294 * error. 295 */ 296 if (PTR_ERR(bridge) == -ENODEV) 297 return 0; 298 else 299 return PTR_ERR(bridge); 300 } 301 302 return drm_bridge_attach(&dpi->encoder.base, bridge, NULL, 0); 303 } 304 305 static void vc4_dpi_disable_clock(void *ptr) 306 { 307 struct vc4_dpi *dpi = ptr; 308 309 clk_disable_unprepare(dpi->core_clock); 310 } 311 312 static int vc4_dpi_bind(struct device *dev, struct device *master, void *data) 313 { 314 struct platform_device *pdev = to_platform_device(dev); 315 struct drm_device *drm = dev_get_drvdata(master); 316 struct vc4_dpi *dpi; 317 int ret; 318 319 dpi = drmm_kzalloc(drm, sizeof(*dpi), GFP_KERNEL); 320 if (!dpi) 321 return -ENOMEM; 322 323 dpi->encoder.type = VC4_ENCODER_TYPE_DPI; 324 dpi->pdev = pdev; 325 dpi->regs = vc4_ioremap_regs(pdev, 0); 326 if (IS_ERR(dpi->regs)) 327 return PTR_ERR(dpi->regs); 328 dpi->regset.base = dpi->regs; 329 dpi->regset.regs = dpi_regs; 330 dpi->regset.nregs = ARRAY_SIZE(dpi_regs); 331 332 if (DPI_READ(DPI_ID) != DPI_ID_VALUE) { 333 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n", 334 DPI_READ(DPI_ID), DPI_ID_VALUE); 335 return -ENODEV; 336 } 337 338 dpi->core_clock = devm_clk_get(dev, "core"); 339 if (IS_ERR(dpi->core_clock)) { 340 ret = PTR_ERR(dpi->core_clock); 341 if (ret != -EPROBE_DEFER) 342 DRM_ERROR("Failed to get core clock: %d\n", ret); 343 return ret; 344 } 345 346 dpi->pixel_clock = devm_clk_get(dev, "pixel"); 347 if (IS_ERR(dpi->pixel_clock)) { 348 ret = PTR_ERR(dpi->pixel_clock); 349 if (ret != -EPROBE_DEFER) 350 DRM_ERROR("Failed to get pixel clock: %d\n", ret); 351 return ret; 352 } 353 354 ret = clk_prepare_enable(dpi->core_clock); 355 if (ret) { 356 DRM_ERROR("Failed to turn on core clock: %d\n", ret); 357 return ret; 358 } 359 360 ret = devm_add_action_or_reset(dev, vc4_dpi_disable_clock, dpi); 361 if (ret) 362 return ret; 363 364 ret = drmm_encoder_init(drm, &dpi->encoder.base, 365 &vc4_dpi_encoder_funcs, 366 DRM_MODE_ENCODER_DPI, 367 NULL); 368 if (ret) 369 return ret; 370 371 drm_encoder_helper_add(&dpi->encoder.base, &vc4_dpi_encoder_helper_funcs); 372 373 ret = vc4_dpi_init_bridge(dpi); 374 if (ret) 375 return ret; 376 377 dev_set_drvdata(dev, dpi); 378 379 return 0; 380 } 381 382 static const struct component_ops vc4_dpi_ops = { 383 .bind = vc4_dpi_bind, 384 }; 385 386 static int vc4_dpi_dev_probe(struct platform_device *pdev) 387 { 388 return component_add(&pdev->dev, &vc4_dpi_ops); 389 } 390 391 static int vc4_dpi_dev_remove(struct platform_device *pdev) 392 { 393 component_del(&pdev->dev, &vc4_dpi_ops); 394 return 0; 395 } 396 397 struct platform_driver vc4_dpi_driver = { 398 .probe = vc4_dpi_dev_probe, 399 .remove = vc4_dpi_dev_remove, 400 .driver = { 401 .name = "vc4_dpi", 402 .of_match_table = vc4_dpi_dt_match, 403 }, 404 }; 405