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 static inline struct vc4_dpi * 101 to_vc4_dpi(struct drm_encoder *encoder) 102 { 103 return container_of(encoder, struct vc4_dpi, encoder.base); 104 } 105 106 #define DPI_READ(offset) readl(dpi->regs + (offset)) 107 #define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset)) 108 109 static const struct debugfs_reg32 dpi_regs[] = { 110 VC4_REG32(DPI_C), 111 VC4_REG32(DPI_ID), 112 }; 113 114 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder) 115 { 116 struct drm_device *dev = encoder->dev; 117 struct vc4_dpi *dpi = to_vc4_dpi(encoder); 118 int idx; 119 120 if (!drm_dev_enter(dev, &idx)) 121 return; 122 123 clk_disable_unprepare(dpi->pixel_clock); 124 125 drm_dev_exit(idx); 126 } 127 128 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder) 129 { 130 struct drm_device *dev = encoder->dev; 131 struct drm_display_mode *mode = &encoder->crtc->mode; 132 struct vc4_dpi *dpi = to_vc4_dpi(encoder); 133 struct drm_connector_list_iter conn_iter; 134 struct drm_connector *connector = NULL, *connector_scan; 135 u32 dpi_c = DPI_ENABLE; 136 int idx; 137 int ret; 138 139 /* Look up the connector attached to DPI so we can get the 140 * bus_format. Ideally the bridge would tell us the 141 * bus_format we want, but it doesn't yet, so assume that it's 142 * uniform throughout the bridge chain. 143 */ 144 drm_connector_list_iter_begin(dev, &conn_iter); 145 drm_for_each_connector_iter(connector_scan, &conn_iter) { 146 if (connector_scan->encoder == encoder) { 147 connector = connector_scan; 148 break; 149 } 150 } 151 drm_connector_list_iter_end(&conn_iter); 152 153 /* Default to 24bit if no connector or format found. */ 154 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT); 155 156 if (connector) { 157 if (connector->display_info.num_bus_formats) { 158 u32 bus_format = connector->display_info.bus_formats[0]; 159 160 dpi_c &= ~DPI_FORMAT_MASK; 161 162 switch (bus_format) { 163 case MEDIA_BUS_FMT_RGB888_1X24: 164 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, 165 DPI_FORMAT); 166 break; 167 case MEDIA_BUS_FMT_BGR888_1X24: 168 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, 169 DPI_FORMAT); 170 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, 171 DPI_ORDER); 172 break; 173 case MEDIA_BUS_FMT_RGB666_1X24_CPADHI: 174 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2, 175 DPI_FORMAT); 176 break; 177 case MEDIA_BUS_FMT_RGB666_1X18: 178 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1, 179 DPI_FORMAT); 180 break; 181 case MEDIA_BUS_FMT_RGB565_1X16: 182 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3, 183 DPI_FORMAT); 184 break; 185 default: 186 DRM_ERROR("Unknown media bus format %d\n", 187 bus_format); 188 break; 189 } 190 } 191 192 if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE) 193 dpi_c |= DPI_PIXEL_CLK_INVERT; 194 195 if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW) 196 dpi_c |= DPI_OUTPUT_ENABLE_INVERT; 197 } 198 199 if (mode->flags & DRM_MODE_FLAG_CSYNC) { 200 if (mode->flags & DRM_MODE_FLAG_NCSYNC) 201 dpi_c |= DPI_OUTPUT_ENABLE_INVERT; 202 } else { 203 dpi_c |= DPI_OUTPUT_ENABLE_MODE; 204 205 if (mode->flags & DRM_MODE_FLAG_NHSYNC) 206 dpi_c |= DPI_HSYNC_INVERT; 207 else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC)) 208 dpi_c |= DPI_HSYNC_DISABLE; 209 210 if (mode->flags & DRM_MODE_FLAG_NVSYNC) 211 dpi_c |= DPI_VSYNC_INVERT; 212 else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC)) 213 dpi_c |= DPI_VSYNC_DISABLE; 214 } 215 216 if (!drm_dev_enter(dev, &idx)) 217 return; 218 219 DPI_WRITE(DPI_C, dpi_c); 220 221 ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000); 222 if (ret) 223 DRM_ERROR("Failed to set clock rate: %d\n", ret); 224 225 ret = clk_prepare_enable(dpi->pixel_clock); 226 if (ret) 227 DRM_ERROR("Failed to set clock rate: %d\n", ret); 228 229 drm_dev_exit(idx); 230 } 231 232 static enum drm_mode_status vc4_dpi_encoder_mode_valid(struct drm_encoder *encoder, 233 const struct drm_display_mode *mode) 234 { 235 if (mode->flags & DRM_MODE_FLAG_INTERLACE) 236 return MODE_NO_INTERLACE; 237 238 return MODE_OK; 239 } 240 241 static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = { 242 .disable = vc4_dpi_encoder_disable, 243 .enable = vc4_dpi_encoder_enable, 244 .mode_valid = vc4_dpi_encoder_mode_valid, 245 }; 246 247 static int vc4_dpi_late_register(struct drm_encoder *encoder) 248 { 249 struct drm_device *drm = encoder->dev; 250 struct vc4_dpi *dpi = to_vc4_dpi(encoder); 251 int ret; 252 253 ret = vc4_debugfs_add_regset32(drm->primary, "dpi_regs", &dpi->regset); 254 if (ret) 255 return ret; 256 257 return 0; 258 } 259 260 static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = { 261 .late_register = vc4_dpi_late_register, 262 }; 263 264 static const struct of_device_id vc4_dpi_dt_match[] = { 265 { .compatible = "brcm,bcm2835-dpi", .data = NULL }, 266 {} 267 }; 268 269 /* Sets up the next link in the display chain, whether it's a panel or 270 * a bridge. 271 */ 272 static int vc4_dpi_init_bridge(struct vc4_dpi *dpi) 273 { 274 struct drm_device *drm = dpi->encoder.base.dev; 275 struct device *dev = &dpi->pdev->dev; 276 struct drm_bridge *bridge; 277 278 bridge = drmm_of_get_bridge(drm, dev->of_node, 0, 0); 279 if (IS_ERR(bridge)) { 280 /* If nothing was connected in the DT, that's not an 281 * error. 282 */ 283 if (PTR_ERR(bridge) == -ENODEV) 284 return 0; 285 else 286 return PTR_ERR(bridge); 287 } 288 289 return drm_bridge_attach(&dpi->encoder.base, bridge, NULL, 0); 290 } 291 292 static void vc4_dpi_disable_clock(void *ptr) 293 { 294 struct vc4_dpi *dpi = ptr; 295 296 clk_disable_unprepare(dpi->core_clock); 297 } 298 299 static int vc4_dpi_bind(struct device *dev, struct device *master, void *data) 300 { 301 struct platform_device *pdev = to_platform_device(dev); 302 struct drm_device *drm = dev_get_drvdata(master); 303 struct vc4_dpi *dpi; 304 int ret; 305 306 dpi = drmm_kzalloc(drm, sizeof(*dpi), GFP_KERNEL); 307 if (!dpi) 308 return -ENOMEM; 309 310 dpi->encoder.type = VC4_ENCODER_TYPE_DPI; 311 dpi->pdev = pdev; 312 dpi->regs = vc4_ioremap_regs(pdev, 0); 313 if (IS_ERR(dpi->regs)) 314 return PTR_ERR(dpi->regs); 315 dpi->regset.base = dpi->regs; 316 dpi->regset.regs = dpi_regs; 317 dpi->regset.nregs = ARRAY_SIZE(dpi_regs); 318 319 if (DPI_READ(DPI_ID) != DPI_ID_VALUE) { 320 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n", 321 DPI_READ(DPI_ID), DPI_ID_VALUE); 322 return -ENODEV; 323 } 324 325 dpi->core_clock = devm_clk_get(dev, "core"); 326 if (IS_ERR(dpi->core_clock)) { 327 ret = PTR_ERR(dpi->core_clock); 328 if (ret != -EPROBE_DEFER) 329 DRM_ERROR("Failed to get core clock: %d\n", ret); 330 return ret; 331 } 332 333 dpi->pixel_clock = devm_clk_get(dev, "pixel"); 334 if (IS_ERR(dpi->pixel_clock)) { 335 ret = PTR_ERR(dpi->pixel_clock); 336 if (ret != -EPROBE_DEFER) 337 DRM_ERROR("Failed to get pixel clock: %d\n", ret); 338 return ret; 339 } 340 341 ret = clk_prepare_enable(dpi->core_clock); 342 if (ret) { 343 DRM_ERROR("Failed to turn on core clock: %d\n", ret); 344 return ret; 345 } 346 347 ret = devm_add_action_or_reset(dev, vc4_dpi_disable_clock, dpi); 348 if (ret) 349 return ret; 350 351 ret = drmm_encoder_init(drm, &dpi->encoder.base, 352 &vc4_dpi_encoder_funcs, 353 DRM_MODE_ENCODER_DPI, 354 NULL); 355 if (ret) 356 return ret; 357 358 drm_encoder_helper_add(&dpi->encoder.base, &vc4_dpi_encoder_helper_funcs); 359 360 ret = vc4_dpi_init_bridge(dpi); 361 if (ret) 362 return ret; 363 364 dev_set_drvdata(dev, dpi); 365 366 return 0; 367 } 368 369 static const struct component_ops vc4_dpi_ops = { 370 .bind = vc4_dpi_bind, 371 }; 372 373 static int vc4_dpi_dev_probe(struct platform_device *pdev) 374 { 375 return component_add(&pdev->dev, &vc4_dpi_ops); 376 } 377 378 static int vc4_dpi_dev_remove(struct platform_device *pdev) 379 { 380 component_del(&pdev->dev, &vc4_dpi_ops); 381 return 0; 382 } 383 384 struct platform_driver vc4_dpi_driver = { 385 .probe = vc4_dpi_dev_probe, 386 .remove = vc4_dpi_dev_remove, 387 .driver = { 388 .name = "vc4_dpi", 389 .of_match_table = vc4_dpi_dt_match, 390 }, 391 }; 392