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 #include <drm/drmP.h> 29 #include <drm/drm_panel.h> 30 31 #include <linux/bitops.h> 32 #include <linux/init.h> 33 #include <linux/kernel.h> 34 #include <linux/mfd/syscon.h> 35 #include <linux/module.h> 36 #include <linux/platform_device.h> 37 #include <linux/regmap.h> 38 39 #include <video/of_videomode.h> 40 #include <video/videomode.h> 41 42 /* 43 * This configuration register in the Versatile and RealView 44 * family is uniformly present but appears more and more 45 * unutilized starting with the RealView series. 46 */ 47 #define SYS_CLCD 0x50 48 49 /* The Versatile can detect the connected panel type */ 50 #define SYS_CLCD_CLCDID_MASK (BIT(8)|BIT(9)|BIT(10)|BIT(11)|BIT(12)) 51 #define SYS_CLCD_ID_SANYO_3_8 (0x00 << 8) 52 #define SYS_CLCD_ID_SHARP_8_4 (0x01 << 8) 53 #define SYS_CLCD_ID_EPSON_2_2 (0x02 << 8) 54 #define SYS_CLCD_ID_SANYO_2_5 (0x07 << 8) 55 #define SYS_CLCD_ID_VGA (0x1f << 8) 56 57 /* IB2 control register for the Versatile daughterboard */ 58 #define IB2_CTRL 0x00 59 #define IB2_CTRL_LCD_SD BIT(1) /* 1 = shut down LCD */ 60 #define IB2_CTRL_LCD_BL_ON BIT(0) 61 #define IB2_CTRL_LCD_MASK (BIT(0)|BIT(1)) 62 63 /** 64 * struct versatile_panel_type - lookup struct for the supported panels 65 */ 66 struct versatile_panel_type { 67 /** 68 * @name: the name of this panel 69 */ 70 const char *name; 71 /** 72 * @magic: the magic value from the detection register 73 */ 74 u32 magic; 75 /** 76 * @mode: the DRM display mode for this panel 77 */ 78 struct drm_display_mode mode; 79 /** 80 * @bus_flags: the DRM bus flags for this panel e.g. inverted clock 81 */ 82 u32 bus_flags; 83 /** 84 * @width_mm: the panel width in mm 85 */ 86 u32 width_mm; 87 /** 88 * @height_mm: the panel height in mm 89 */ 90 u32 height_mm; 91 /** 92 * @ib2: the panel may be connected on an IB2 daughterboard 93 */ 94 bool ib2; 95 }; 96 97 /** 98 * struct versatile_panel - state container for the Versatile panels 99 */ 100 struct versatile_panel { 101 /** 102 * @dev: the container device 103 */ 104 struct device *dev; 105 /** 106 * @panel: the DRM panel instance for this device 107 */ 108 struct drm_panel panel; 109 /** 110 * @panel_type: the Versatile panel type as detected 111 */ 112 const struct versatile_panel_type *panel_type; 113 /** 114 * @map: map to the parent syscon where the main register reside 115 */ 116 struct regmap *map; 117 /** 118 * @ib2_map: map to the IB2 syscon, if applicable 119 */ 120 struct regmap *ib2_map; 121 }; 122 123 static const struct versatile_panel_type versatile_panels[] = { 124 /* 125 * Sanyo TM38QV67A02A - 3.8 inch QVGA (320x240) Color TFT 126 * found on the Versatile AB IB1 connector or the Versatile 127 * PB adaptor board connector. 128 */ 129 { 130 .name = "Sanyo TM38QV67A02A", 131 .magic = SYS_CLCD_ID_SANYO_3_8, 132 .width_mm = 79, 133 .height_mm = 54, 134 .mode = { 135 .clock = 10000, 136 .hdisplay = 320, 137 .hsync_start = 320 + 6, 138 .hsync_end = 320 + 6 + 6, 139 .htotal = 320 + 6 + 6 + 6, 140 .vdisplay = 240, 141 .vsync_start = 240 + 5, 142 .vsync_end = 240 + 5 + 6, 143 .vtotal = 240 + 5 + 6 + 5, 144 .vrefresh = 116, 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 .vrefresh = 60, 169 .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC, 170 }, 171 }, 172 /* 173 * Epson L2F50113T00 - 2.2 inch QCIF 176x220 Color TFT 174 * found on the Versatile PB adaptor board connector. 175 */ 176 { 177 .name = "Epson L2F50113T00", 178 .magic = SYS_CLCD_ID_EPSON_2_2, 179 .width_mm = 34, 180 .height_mm = 45, 181 .mode = { 182 .clock = 62500, 183 .hdisplay = 176, 184 .hsync_start = 176 + 2, 185 .hsync_end = 176 + 2 + 3, 186 .htotal = 176 + 2 + 3 + 3, 187 .vdisplay = 220, 188 .vsync_start = 220 + 0, 189 .vsync_end = 220 + 0 + 2, 190 .vtotal = 220 + 0 + 2 + 1, 191 .vrefresh = 390, 192 .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC, 193 }, 194 .bus_flags = DRM_BUS_FLAG_PIXDATA_NEGEDGE, 195 }, 196 /* 197 * Sanyo ALR252RGT 240x320 portrait display found on the 198 * Versatile AB IB2 daughterboard for GSM prototyping. 199 */ 200 { 201 .name = "Sanyo ALR252RGT", 202 .magic = SYS_CLCD_ID_SANYO_2_5, 203 .width_mm = 37, 204 .height_mm = 50, 205 .mode = { 206 .clock = 5400, 207 .hdisplay = 240, 208 .hsync_start = 240 + 10, 209 .hsync_end = 240 + 10 + 10, 210 .htotal = 240 + 10 + 10 + 20, 211 .vdisplay = 320, 212 .vsync_start = 320 + 2, 213 .vsync_end = 320 + 2 + 2, 214 .vtotal = 320 + 2 + 2 + 2, 215 .vrefresh = 116, 216 .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC, 217 }, 218 .bus_flags = DRM_BUS_FLAG_PIXDATA_NEGEDGE, 219 .ib2 = true, 220 }, 221 }; 222 223 static inline struct versatile_panel * 224 to_versatile_panel(struct drm_panel *panel) 225 { 226 return container_of(panel, struct versatile_panel, panel); 227 } 228 229 static int versatile_panel_disable(struct drm_panel *panel) 230 { 231 struct versatile_panel *vpanel = to_versatile_panel(panel); 232 233 /* If we're on an IB2 daughterboard, turn off display */ 234 if (vpanel->ib2_map) { 235 dev_dbg(vpanel->dev, "disable IB2 display\n"); 236 regmap_update_bits(vpanel->ib2_map, 237 IB2_CTRL, 238 IB2_CTRL_LCD_MASK, 239 IB2_CTRL_LCD_SD); 240 } 241 242 return 0; 243 } 244 245 static int versatile_panel_enable(struct drm_panel *panel) 246 { 247 struct versatile_panel *vpanel = to_versatile_panel(panel); 248 249 /* If we're on an IB2 daughterboard, turn on display */ 250 if (vpanel->ib2_map) { 251 dev_dbg(vpanel->dev, "enable IB2 display\n"); 252 regmap_update_bits(vpanel->ib2_map, 253 IB2_CTRL, 254 IB2_CTRL_LCD_MASK, 255 IB2_CTRL_LCD_BL_ON); 256 } 257 258 return 0; 259 } 260 261 static int versatile_panel_get_modes(struct drm_panel *panel) 262 { 263 struct drm_connector *connector = panel->connector; 264 struct versatile_panel *vpanel = to_versatile_panel(panel); 265 struct drm_display_mode *mode; 266 267 strncpy(connector->display_info.name, vpanel->panel_type->name, 268 DRM_DISPLAY_INFO_LEN); 269 connector->display_info.width_mm = vpanel->panel_type->width_mm; 270 connector->display_info.height_mm = vpanel->panel_type->height_mm; 271 connector->display_info.bus_flags = vpanel->panel_type->bus_flags; 272 273 mode = drm_mode_duplicate(panel->drm, &vpanel->panel_type->mode); 274 drm_mode_set_name(mode); 275 mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED; 276 277 mode->width_mm = vpanel->panel_type->width_mm; 278 mode->height_mm = vpanel->panel_type->height_mm; 279 drm_mode_probed_add(connector, mode); 280 281 return 1; 282 } 283 284 static const struct drm_panel_funcs versatile_panel_drm_funcs = { 285 .disable = versatile_panel_disable, 286 .enable = versatile_panel_enable, 287 .get_modes = versatile_panel_get_modes, 288 }; 289 290 static int versatile_panel_probe(struct platform_device *pdev) 291 { 292 struct device *dev = &pdev->dev; 293 struct versatile_panel *vpanel; 294 struct device *parent; 295 struct regmap *map; 296 int ret; 297 u32 val; 298 int i; 299 300 parent = dev->parent; 301 if (!parent) { 302 dev_err(dev, "no parent for versatile panel\n"); 303 return -ENODEV; 304 } 305 map = syscon_node_to_regmap(parent->of_node); 306 if (IS_ERR(map)) { 307 dev_err(dev, "no regmap for versatile panel parent\n"); 308 return PTR_ERR(map); 309 } 310 311 vpanel = devm_kzalloc(dev, sizeof(*vpanel), GFP_KERNEL); 312 if (!vpanel) 313 return -ENOMEM; 314 315 ret = regmap_read(map, SYS_CLCD, &val); 316 if (ret) { 317 dev_err(dev, "cannot access syscon regs\n"); 318 return ret; 319 } 320 321 val &= SYS_CLCD_CLCDID_MASK; 322 323 for (i = 0; i < ARRAY_SIZE(versatile_panels); i++) { 324 const struct versatile_panel_type *pt; 325 326 pt = &versatile_panels[i]; 327 if (pt->magic == val) { 328 vpanel->panel_type = pt; 329 break; 330 } 331 } 332 333 /* No panel detected or VGA, let's leave this show */ 334 if (i == ARRAY_SIZE(versatile_panels)) { 335 dev_info(dev, "no panel detected\n"); 336 return -ENODEV; 337 } 338 339 dev_info(dev, "detected: %s\n", vpanel->panel_type->name); 340 vpanel->dev = dev; 341 vpanel->map = map; 342 343 /* Check if the panel is mounted on an IB2 daughterboard */ 344 if (vpanel->panel_type->ib2) { 345 vpanel->ib2_map = syscon_regmap_lookup_by_compatible( 346 "arm,versatile-ib2-syscon"); 347 if (IS_ERR(vpanel->ib2_map)) 348 vpanel->ib2_map = NULL; 349 else 350 dev_info(dev, "panel mounted on IB2 daughterboard\n"); 351 } 352 353 drm_panel_init(&vpanel->panel); 354 vpanel->panel.dev = dev; 355 vpanel->panel.funcs = &versatile_panel_drm_funcs; 356 357 return drm_panel_add(&vpanel->panel); 358 } 359 360 static const struct of_device_id versatile_panel_match[] = { 361 { .compatible = "arm,versatile-tft-panel", }, 362 {}, 363 }; 364 MODULE_DEVICE_TABLE(of, versatile_panel_match); 365 366 static struct platform_driver versatile_panel_driver = { 367 .probe = versatile_panel_probe, 368 .driver = { 369 .name = "versatile-tft-panel", 370 .of_match_table = versatile_panel_match, 371 }, 372 }; 373 module_platform_driver(versatile_panel_driver); 374 375 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); 376 MODULE_DESCRIPTION("ARM Versatile panel driver"); 377 MODULE_LICENSE("GPL v2"); 378