1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Panel driver for the ARM Versatile family reference designs from 4 * ARM Limited. 5 * 6 * Author: 7 * Linus Walleij <linus.wallei@linaro.org> 8 * 9 * On the Versatile AB, these panels come mounted on daughterboards 10 * named "IB1" or "IB2" (Interface Board 1 & 2 respectively.) They 11 * are documented in ARM DUI 0225D Appendix C and D. These daughter 12 * boards support TFT display panels. 13 * 14 * - The IB1 is a passive board where the display connector defines a 15 * few wires for encoding the display type for autodetection, 16 * suitable display settings can then be looked up from this setting. 17 * The magic bits can be read out from the system controller. 18 * 19 * - The IB2 is a more complex board intended for GSM phone development 20 * with some logic and a control register, which needs to be accessed 21 * and the board display needs to be turned on explicitly. 22 * 23 * On the Versatile PB, a special CLCD adaptor board is available 24 * supporting the same displays as the Versatile AB, plus one more 25 * Epson QCIF display. 26 * 27 */ 28 29 #include <linux/bitops.h> 30 #include <linux/init.h> 31 #include <linux/kernel.h> 32 #include <linux/mfd/syscon.h> 33 #include <linux/module.h> 34 #include <linux/platform_device.h> 35 #include <linux/regmap.h> 36 37 #include <video/of_videomode.h> 38 #include <video/videomode.h> 39 40 #include <drm/drm_modes.h> 41 #include <drm/drm_panel.h> 42 43 /* 44 * This configuration register in the Versatile and RealView 45 * family is uniformly present but appears more and more 46 * unutilized starting with the RealView series. 47 */ 48 #define SYS_CLCD 0x50 49 50 /* The Versatile can detect the connected panel type */ 51 #define SYS_CLCD_CLCDID_MASK (BIT(8)|BIT(9)|BIT(10)|BIT(11)|BIT(12)) 52 #define SYS_CLCD_ID_SANYO_3_8 (0x00 << 8) 53 #define SYS_CLCD_ID_SHARP_8_4 (0x01 << 8) 54 #define SYS_CLCD_ID_EPSON_2_2 (0x02 << 8) 55 #define SYS_CLCD_ID_SANYO_2_5 (0x07 << 8) 56 #define SYS_CLCD_ID_VGA (0x1f << 8) 57 58 /* IB2 control register for the Versatile daughterboard */ 59 #define IB2_CTRL 0x00 60 #define IB2_CTRL_LCD_SD BIT(1) /* 1 = shut down LCD */ 61 #define IB2_CTRL_LCD_BL_ON BIT(0) 62 #define IB2_CTRL_LCD_MASK (BIT(0)|BIT(1)) 63 64 /** 65 * struct versatile_panel_type - lookup struct for the supported panels 66 */ 67 struct versatile_panel_type { 68 /** 69 * @name: the name of this panel 70 */ 71 const char *name; 72 /** 73 * @magic: the magic value from the detection register 74 */ 75 u32 magic; 76 /** 77 * @mode: the DRM display mode for this panel 78 */ 79 struct drm_display_mode mode; 80 /** 81 * @bus_flags: the DRM bus flags for this panel e.g. inverted clock 82 */ 83 u32 bus_flags; 84 /** 85 * @width_mm: the panel width in mm 86 */ 87 u32 width_mm; 88 /** 89 * @height_mm: the panel height in mm 90 */ 91 u32 height_mm; 92 /** 93 * @ib2: the panel may be connected on an IB2 daughterboard 94 */ 95 bool ib2; 96 }; 97 98 /** 99 * struct versatile_panel - state container for the Versatile panels 100 */ 101 struct versatile_panel { 102 /** 103 * @dev: the container device 104 */ 105 struct device *dev; 106 /** 107 * @panel: the DRM panel instance for this device 108 */ 109 struct drm_panel panel; 110 /** 111 * @panel_type: the Versatile panel type as detected 112 */ 113 const struct versatile_panel_type *panel_type; 114 /** 115 * @map: map to the parent syscon where the main register reside 116 */ 117 struct regmap *map; 118 /** 119 * @ib2_map: map to the IB2 syscon, if applicable 120 */ 121 struct regmap *ib2_map; 122 }; 123 124 static const struct versatile_panel_type versatile_panels[] = { 125 /* 126 * Sanyo TM38QV67A02A - 3.8 inch QVGA (320x240) Color TFT 127 * found on the Versatile AB IB1 connector or the Versatile 128 * PB adaptor board connector. 129 */ 130 { 131 .name = "Sanyo TM38QV67A02A", 132 .magic = SYS_CLCD_ID_SANYO_3_8, 133 .width_mm = 79, 134 .height_mm = 54, 135 .mode = { 136 .clock = 10000, 137 .hdisplay = 320, 138 .hsync_start = 320 + 6, 139 .hsync_end = 320 + 6 + 6, 140 .htotal = 320 + 6 + 6 + 6, 141 .vdisplay = 240, 142 .vsync_start = 240 + 5, 143 .vsync_end = 240 + 5 + 6, 144 .vtotal = 240 + 5 + 6 + 5, 145 .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC, 146 }, 147 }, 148 /* 149 * Sharp LQ084V1DG21 640x480 VGA Color TFT module 150 * found on the Versatile AB IB1 connector or the Versatile 151 * PB adaptor board connector. 152 */ 153 { 154 .name = "Sharp LQ084V1DG21", 155 .magic = SYS_CLCD_ID_SHARP_8_4, 156 .width_mm = 171, 157 .height_mm = 130, 158 .mode = { 159 .clock = 25000, 160 .hdisplay = 640, 161 .hsync_start = 640 + 24, 162 .hsync_end = 640 + 24 + 96, 163 .htotal = 640 + 24 + 96 + 24, 164 .vdisplay = 480, 165 .vsync_start = 480 + 11, 166 .vsync_end = 480 + 11 + 2, 167 .vtotal = 480 + 11 + 2 + 32, 168 .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC, 169 }, 170 }, 171 /* 172 * Epson L2F50113T00 - 2.2 inch QCIF 176x220 Color TFT 173 * found on the Versatile PB adaptor board connector. 174 */ 175 { 176 .name = "Epson L2F50113T00", 177 .magic = SYS_CLCD_ID_EPSON_2_2, 178 .width_mm = 34, 179 .height_mm = 45, 180 .mode = { 181 .clock = 62500, 182 .hdisplay = 176, 183 .hsync_start = 176 + 2, 184 .hsync_end = 176 + 2 + 3, 185 .htotal = 176 + 2 + 3 + 3, 186 .vdisplay = 220, 187 .vsync_start = 220 + 0, 188 .vsync_end = 220 + 0 + 2, 189 .vtotal = 220 + 0 + 2 + 1, 190 .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC, 191 }, 192 .bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE, 193 }, 194 /* 195 * Sanyo ALR252RGT 240x320 portrait display found on the 196 * Versatile AB IB2 daughterboard for GSM prototyping. 197 */ 198 { 199 .name = "Sanyo ALR252RGT", 200 .magic = SYS_CLCD_ID_SANYO_2_5, 201 .width_mm = 37, 202 .height_mm = 50, 203 .mode = { 204 .clock = 5400, 205 .hdisplay = 240, 206 .hsync_start = 240 + 10, 207 .hsync_end = 240 + 10 + 10, 208 .htotal = 240 + 10 + 10 + 20, 209 .vdisplay = 320, 210 .vsync_start = 320 + 2, 211 .vsync_end = 320 + 2 + 2, 212 .vtotal = 320 + 2 + 2 + 2, 213 .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC, 214 }, 215 .bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE, 216 .ib2 = true, 217 }, 218 }; 219 220 static inline struct versatile_panel * 221 to_versatile_panel(struct drm_panel *panel) 222 { 223 return container_of(panel, struct versatile_panel, panel); 224 } 225 226 static int versatile_panel_disable(struct drm_panel *panel) 227 { 228 struct versatile_panel *vpanel = to_versatile_panel(panel); 229 230 /* If we're on an IB2 daughterboard, turn off display */ 231 if (vpanel->ib2_map) { 232 dev_dbg(vpanel->dev, "disable IB2 display\n"); 233 regmap_update_bits(vpanel->ib2_map, 234 IB2_CTRL, 235 IB2_CTRL_LCD_MASK, 236 IB2_CTRL_LCD_SD); 237 } 238 239 return 0; 240 } 241 242 static int versatile_panel_enable(struct drm_panel *panel) 243 { 244 struct versatile_panel *vpanel = to_versatile_panel(panel); 245 246 /* If we're on an IB2 daughterboard, turn on display */ 247 if (vpanel->ib2_map) { 248 dev_dbg(vpanel->dev, "enable IB2 display\n"); 249 regmap_update_bits(vpanel->ib2_map, 250 IB2_CTRL, 251 IB2_CTRL_LCD_MASK, 252 IB2_CTRL_LCD_BL_ON); 253 } 254 255 return 0; 256 } 257 258 static int versatile_panel_get_modes(struct drm_panel *panel, 259 struct drm_connector *connector) 260 { 261 struct versatile_panel *vpanel = to_versatile_panel(panel); 262 struct drm_display_mode *mode; 263 264 connector->display_info.width_mm = vpanel->panel_type->width_mm; 265 connector->display_info.height_mm = vpanel->panel_type->height_mm; 266 connector->display_info.bus_flags = vpanel->panel_type->bus_flags; 267 268 mode = drm_mode_duplicate(connector->dev, &vpanel->panel_type->mode); 269 if (!mode) 270 return -ENOMEM; 271 drm_mode_set_name(mode); 272 mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED; 273 274 mode->width_mm = vpanel->panel_type->width_mm; 275 mode->height_mm = vpanel->panel_type->height_mm; 276 drm_mode_probed_add(connector, mode); 277 278 return 1; 279 } 280 281 static const struct drm_panel_funcs versatile_panel_drm_funcs = { 282 .disable = versatile_panel_disable, 283 .enable = versatile_panel_enable, 284 .get_modes = versatile_panel_get_modes, 285 }; 286 287 static int versatile_panel_probe(struct platform_device *pdev) 288 { 289 struct device *dev = &pdev->dev; 290 struct versatile_panel *vpanel; 291 struct device *parent; 292 struct regmap *map; 293 int ret; 294 u32 val; 295 int i; 296 297 parent = dev->parent; 298 if (!parent) { 299 dev_err(dev, "no parent for versatile panel\n"); 300 return -ENODEV; 301 } 302 map = syscon_node_to_regmap(parent->of_node); 303 if (IS_ERR(map)) { 304 dev_err(dev, "no regmap for versatile panel parent\n"); 305 return PTR_ERR(map); 306 } 307 308 vpanel = devm_drm_panel_alloc(dev, struct versatile_panel, panel, 309 &versatile_panel_drm_funcs, 310 DRM_MODE_CONNECTOR_DPI); 311 if (IS_ERR(vpanel)) 312 return PTR_ERR(vpanel); 313 314 ret = regmap_read(map, SYS_CLCD, &val); 315 if (ret) { 316 dev_err(dev, "cannot access syscon regs\n"); 317 return ret; 318 } 319 320 val &= SYS_CLCD_CLCDID_MASK; 321 322 for (i = 0; i < ARRAY_SIZE(versatile_panels); i++) { 323 const struct versatile_panel_type *pt; 324 325 pt = &versatile_panels[i]; 326 if (pt->magic == val) { 327 vpanel->panel_type = pt; 328 break; 329 } 330 } 331 332 /* No panel detected or VGA, let's leave this show */ 333 if (i == ARRAY_SIZE(versatile_panels)) { 334 dev_info(dev, "no panel detected\n"); 335 return -ENODEV; 336 } 337 338 dev_info(dev, "detected: %s\n", vpanel->panel_type->name); 339 vpanel->dev = dev; 340 vpanel->map = map; 341 342 /* Check if the panel is mounted on an IB2 daughterboard */ 343 if (vpanel->panel_type->ib2) { 344 vpanel->ib2_map = syscon_regmap_lookup_by_compatible( 345 "arm,versatile-ib2-syscon"); 346 if (IS_ERR(vpanel->ib2_map)) 347 vpanel->ib2_map = NULL; 348 else 349 dev_info(dev, "panel mounted on IB2 daughterboard\n"); 350 } 351 352 drm_panel_add(&vpanel->panel); 353 354 return 0; 355 } 356 357 static const struct of_device_id versatile_panel_match[] = { 358 { .compatible = "arm,versatile-tft-panel", }, 359 {}, 360 }; 361 MODULE_DEVICE_TABLE(of, versatile_panel_match); 362 363 static struct platform_driver versatile_panel_driver = { 364 .probe = versatile_panel_probe, 365 .driver = { 366 .name = "versatile-tft-panel", 367 .of_match_table = versatile_panel_match, 368 }, 369 }; 370 module_platform_driver(versatile_panel_driver); 371 372 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); 373 MODULE_DESCRIPTION("ARM Versatile panel driver"); 374 MODULE_LICENSE("GPL v2"); 375