drivers/gpu/drm/panel/panel-arm-versatile.c

   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/mod_devicetable.h>
  34 #include <linux/module.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/regmap.h>
  37
  38 #include <video/of_videomode.h>
  39 #include <video/videomode.h>
  40
  41 #include <drm/drm_modes.h>
  42 #include <drm/drm_panel.h>
  43
  44 /*
  45  * This configuration register in the Versatile and RealView
  46  * family is uniformly present but appears more and more
  47  * unutilized starting with the RealView series.
  48  */
  49 #define SYS_CLCD                        0x50
  50
  51 /* The Versatile can detect the connected panel type */
  52 #define SYS_CLCD_CLCDID_MASK            (BIT(8)|BIT(9)|BIT(10)|BIT(11)|BIT(12))
  53 #define SYS_CLCD_ID_SANYO_3_8           (0x00 << 8)
  54 #define SYS_CLCD_ID_SHARP_8_4           (0x01 << 8)
  55 #define SYS_CLCD_ID_EPSON_2_2           (0x02 << 8)
  56 #define SYS_CLCD_ID_SANYO_2_5           (0x07 << 8)
  57 #define SYS_CLCD_ID_VGA                 (0x1f << 8)
  58
  59 /* IB2 control register for the Versatile daughterboard */
  60 #define IB2_CTRL                        0x00
  61 #define IB2_CTRL_LCD_SD                 BIT(1) /* 1 = shut down LCD */
  62 #define IB2_CTRL_LCD_BL_ON              BIT(0)
  63 #define IB2_CTRL_LCD_MASK               (BIT(0)|BIT(1))
  64
  65 /**
  66  * struct versatile_panel_type - lookup struct for the supported panels
  67  */
  68 struct versatile_panel_type {
  69         /**
  70          * @name: the name of this panel
  71          */
  72         const char *name;
  73         /**
  74          * @magic: the magic value from the detection register
  75          */
  76         u32 magic;
  77         /**
  78          * @mode: the DRM display mode for this panel
  79          */
  80         struct drm_display_mode mode;
  81         /**
  82          * @bus_flags: the DRM bus flags for this panel e.g. inverted clock
  83          */
  84         u32 bus_flags;
  85         /**
  86          * @width_mm: the panel width in mm
  87          */
  88         u32 width_mm;
  89         /**
  90          * @height_mm: the panel height in mm
  91          */
  92         u32 height_mm;
  93         /**
  94          * @ib2: the panel may be connected on an IB2 daughterboard
  95          */
  96         bool ib2;
  97 };
  98
  99 /**
 100  * struct versatile_panel - state container for the Versatile panels
 101  */
 102 struct versatile_panel {
 103         /**
 104          * @dev: the container device
 105          */
 106         struct device *dev;
 107         /**
 108          * @panel: the DRM panel instance for this device
 109          */
 110         struct drm_panel panel;
 111         /**
 112          * @panel_type: the Versatile panel type as detected
 113          */
 114         const struct versatile_panel_type *panel_type;
 115         /**
 116          * @map: map to the parent syscon where the main register reside
 117          */
 118         struct regmap *map;
 119         /**
 120          * @ib2_map: map to the IB2 syscon, if applicable
 121          */
 122         struct regmap *ib2_map;
 123 };
 124
 125 static const struct versatile_panel_type versatile_panels[] = {
 126         /*
 127          * Sanyo TM38QV67A02A - 3.8 inch QVGA (320x240) Color TFT
 128          * found on the Versatile AB IB1 connector or the Versatile
 129          * PB adaptor board connector.
 130          */
 131         {
 132                 .name = "Sanyo TM38QV67A02A",
 133                 .magic = SYS_CLCD_ID_SANYO_3_8,
 134                 .width_mm = 79,
 135                 .height_mm = 54,
 136                 .mode = {
 137                         .clock = 10000,
 138                         .hdisplay = 320,
 139                         .hsync_start = 320 + 6,
 140                         .hsync_end = 320 + 6 + 6,
 141                         .htotal = 320 + 6 + 6 + 6,
 142                         .vdisplay = 240,
 143                         .vsync_start = 240 + 5,
 144                         .vsync_end = 240 + 5 + 6,
 145                         .vtotal = 240 + 5 + 6 + 5,
 146                         .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
 147                 },
 148         },
 149         /*
 150          * Sharp LQ084V1DG21 640x480 VGA Color TFT module
 151          * found on the Versatile AB IB1 connector or the Versatile
 152          * PB adaptor board connector.
 153          */
 154         {
 155                 .name = "Sharp LQ084V1DG21",
 156                 .magic = SYS_CLCD_ID_SHARP_8_4,
 157                 .width_mm = 171,
 158                 .height_mm = 130,
 159                 .mode = {
 160                         .clock = 25000,
 161                         .hdisplay = 640,
 162                         .hsync_start = 640 + 24,
 163                         .hsync_end = 640 + 24 + 96,
 164                         .htotal = 640 + 24 + 96 + 24,
 165                         .vdisplay = 480,
 166                         .vsync_start = 480 + 11,
 167                         .vsync_end = 480 + 11 + 2,
 168                         .vtotal = 480 + 11 + 2 + 32,
 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                         .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
 192                 },
 193                 .bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
 194         },
 195         /*
 196          * Sanyo ALR252RGT 240x320 portrait display found on the
 197          * Versatile AB IB2 daughterboard for GSM prototyping.
 198          */
 199         {
 200                 .name = "Sanyo ALR252RGT",
 201                 .magic = SYS_CLCD_ID_SANYO_2_5,
 202                 .width_mm = 37,
 203                 .height_mm = 50,
 204                 .mode = {
 205                         .clock = 5400,
 206                         .hdisplay = 240,
 207                         .hsync_start = 240 + 10,
 208                         .hsync_end = 240 + 10 + 10,
 209                         .htotal = 240 + 10 + 10 + 20,
 210                         .vdisplay = 320,
 211                         .vsync_start = 320 + 2,
 212                         .vsync_end = 320 + 2 + 2,
 213                         .vtotal = 320 + 2 + 2 + 2,
 214                         .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
 215                 },
 216                 .bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
 217                 .ib2 = true,
 218         },
 219 };
 220
 221 static inline struct versatile_panel *
 222 to_versatile_panel(struct drm_panel *panel)
 223 {
 224         return container_of(panel, struct versatile_panel, panel);
 225 }
 226
 227 static int versatile_panel_disable(struct drm_panel *panel)
 228 {
 229         struct versatile_panel *vpanel = to_versatile_panel(panel);
 230
 231         /* If we're on an IB2 daughterboard, turn off display */
 232         if (vpanel->ib2_map) {
 233                 dev_dbg(vpanel->dev, "disable IB2 display\n");
 234                 regmap_update_bits(vpanel->ib2_map,
 235                                    IB2_CTRL,
 236                                    IB2_CTRL_LCD_MASK,
 237                                    IB2_CTRL_LCD_SD);
 238         }
 239
 240         return 0;
 241 }
 242
 243 static int versatile_panel_enable(struct drm_panel *panel)
 244 {
 245         struct versatile_panel *vpanel = to_versatile_panel(panel);
 246
 247         /* If we're on an IB2 daughterboard, turn on display */
 248         if (vpanel->ib2_map) {
 249                 dev_dbg(vpanel->dev, "enable IB2 display\n");
 250                 regmap_update_bits(vpanel->ib2_map,
 251                                    IB2_CTRL,
 252                                    IB2_CTRL_LCD_MASK,
 253                                    IB2_CTRL_LCD_BL_ON);
 254         }
 255
 256         return 0;
 257 }
 258
 259 static int versatile_panel_get_modes(struct drm_panel *panel,
 260                                      struct drm_connector *connector)
 261 {
 262         struct versatile_panel *vpanel = to_versatile_panel(panel);
 263         struct drm_display_mode *mode;
 264
 265         connector->display_info.width_mm = vpanel->panel_type->width_mm;
 266         connector->display_info.height_mm = vpanel->panel_type->height_mm;
 267         connector->display_info.bus_flags = vpanel->panel_type->bus_flags;
 268
 269         mode = drm_mode_duplicate(connector->dev, &vpanel->panel_type->mode);
 270         drm_mode_set_name(mode);
 271         mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
 272
 273         mode->width_mm = vpanel->panel_type->width_mm;
 274         mode->height_mm = vpanel->panel_type->height_mm;
 275         drm_mode_probed_add(connector, mode);
 276
 277         return 1;
 278 }
 279
 280 static const struct drm_panel_funcs versatile_panel_drm_funcs = {
 281         .disable = versatile_panel_disable,
 282         .enable = versatile_panel_enable,
 283         .get_modes = versatile_panel_get_modes,
 284 };
 285
 286 static int versatile_panel_probe(struct platform_device *pdev)
 287 {
 288         struct device *dev = &pdev->dev;
 289         struct versatile_panel *vpanel;
 290         struct device *parent;
 291         struct regmap *map;
 292         int ret;
 293         u32 val;
 294         int i;
 295
 296         parent = dev->parent;
 297         if (!parent) {
 298                 dev_err(dev, "no parent for versatile panel\n");
 299                 return -ENODEV;
 300         }
 301         map = syscon_node_to_regmap(parent->of_node);
 302         if (IS_ERR(map)) {
 303                 dev_err(dev, "no regmap for versatile panel parent\n");
 304                 return PTR_ERR(map);
 305         }
 306
 307         vpanel = devm_kzalloc(dev, sizeof(*vpanel), GFP_KERNEL);
 308         if (!vpanel)
 309                 return -ENOMEM;
 310
 311         ret = regmap_read(map, SYS_CLCD, &val);
 312         if (ret) {
 313                 dev_err(dev, "cannot access syscon regs\n");
 314                 return ret;
 315         }
 316
 317         val &= SYS_CLCD_CLCDID_MASK;
 318
 319         for (i = 0; i < ARRAY_SIZE(versatile_panels); i++) {
 320                 const struct versatile_panel_type *pt;
 321
 322                 pt = &versatile_panels[i];
 323                 if (pt->magic == val) {
 324                         vpanel->panel_type = pt;
 325                         break;
 326                 }
 327         }
 328
 329         /* No panel detected or VGA, let's leave this show */
 330         if (i == ARRAY_SIZE(versatile_panels)) {
 331                 dev_info(dev, "no panel detected\n");
 332                 return -ENODEV;
 333         }
 334
 335         dev_info(dev, "detected: %s\n", vpanel->panel_type->name);
 336         vpanel->dev = dev;
 337         vpanel->map = map;
 338
 339         /* Check if the panel is mounted on an IB2 daughterboard */
 340         if (vpanel->panel_type->ib2) {
 341                 vpanel->ib2_map = syscon_regmap_lookup_by_compatible(
 342                         "arm,versatile-ib2-syscon");
 343                 if (IS_ERR(vpanel->ib2_map))
 344                         vpanel->ib2_map = NULL;
 345                 else
 346                         dev_info(dev, "panel mounted on IB2 daughterboard\n");
 347         }
 348
 349         drm_panel_init(&vpanel->panel, dev, &versatile_panel_drm_funcs,
 350                        DRM_MODE_CONNECTOR_DPI);
 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");