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