drm/panel/panel-arm-versatile.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Panel driver for the ARM Versatile family reference designs from
0004  * ARM Limited.
0005  *
0006  * Author:
0007  * Linus Walleij <linus.wallei@linaro.org>
0008  *
0009  * On the Versatile AB, these panels come mounted on daughterboards
0010  * named "IB1" or "IB2" (Interface Board 1 & 2 respectively.) They
0011  * are documented in ARM DUI 0225D Appendix C and D. These daughter
0012  * boards support TFT display panels.
0013  *
0014  * - The IB1 is a passive board where the display connector defines a
0015  *   few wires for encoding the display type for autodetection,
0016  *   suitable display settings can then be looked up from this setting.
0017  *   The magic bits can be read out from the system controller.
0018  *
0019  * - The IB2 is a more complex board intended for GSM phone development
0020  *   with some logic and a control register, which needs to be accessed
0021  *   and the board display needs to be turned on explicitly.
0022  *
0023  * On the Versatile PB, a special CLCD adaptor board is available
0024  * supporting the same displays as the Versatile AB, plus one more
0025  * Epson QCIF display.
0026  *
0027  */
0028
0029 #include <linux/bitops.h>
0030 #include <linux/init.h>
0031 #include <linux/kernel.h>
0032 #include <linux/mfd/syscon.h>
0033 #include <linux/mod_devicetable.h>
0034 #include <linux/module.h>
0035 #include <linux/platform_device.h>
0036 #include <linux/regmap.h>
0037
0038 #include <video/of_videomode.h>
0039 #include <video/videomode.h>
0040
0041 #include <drm/drm_modes.h>
0042 #include <drm/drm_panel.h>
0043
0044 /*
0045  * This configuration register in the Versatile and RealView
0046  * family is uniformly present but appears more and more
0047  * unutilized starting with the RealView series.
0048  */
0049 #define SYS_CLCD            0x50
0050
0051 /* The Versatile can detect the connected panel type */
0052 #define SYS_CLCD_CLCDID_MASK        (BIT(8)|BIT(9)|BIT(10)|BIT(11)|BIT(12))
0053 #define SYS_CLCD_ID_SANYO_3_8       (0x00 << 8)
0054 #define SYS_CLCD_ID_SHARP_8_4       (0x01 << 8)
0055 #define SYS_CLCD_ID_EPSON_2_2       (0x02 << 8)
0056 #define SYS_CLCD_ID_SANYO_2_5       (0x07 << 8)
0057 #define SYS_CLCD_ID_VGA         (0x1f << 8)
0058
0059 /* IB2 control register for the Versatile daughterboard */
0060 #define IB2_CTRL            0x00
0061 #define IB2_CTRL_LCD_SD         BIT(1) /* 1 = shut down LCD */
0062 #define IB2_CTRL_LCD_BL_ON      BIT(0)
0063 #define IB2_CTRL_LCD_MASK       (BIT(0)|BIT(1))
0064
0065 /**
0066  * struct versatile_panel_type - lookup struct for the supported panels
0067  */
0068 struct versatile_panel_type {
0069     /**
0070      * @name: the name of this panel
0071      */
0072     const char *name;
0073     /**
0074      * @magic: the magic value from the detection register
0075      */
0076     u32 magic;
0077     /**
0078      * @mode: the DRM display mode for this panel
0079      */
0080     struct drm_display_mode mode;
0081     /**
0082      * @bus_flags: the DRM bus flags for this panel e.g. inverted clock
0083      */
0084     u32 bus_flags;
0085     /**
0086      * @width_mm: the panel width in mm
0087      */
0088     u32 width_mm;
0089     /**
0090      * @height_mm: the panel height in mm
0091      */
0092     u32 height_mm;
0093     /**
0094      * @ib2: the panel may be connected on an IB2 daughterboard
0095      */
0096     bool ib2;
0097 };
0098
0099 /**
0100  * struct versatile_panel - state container for the Versatile panels
0101  */
0102 struct versatile_panel {
0103     /**
0104      * @dev: the container device
0105      */
0106     struct device *dev;
0107     /**
0108      * @panel: the DRM panel instance for this device
0109      */
0110     struct drm_panel panel;
0111     /**
0112      * @panel_type: the Versatile panel type as detected
0113      */
0114     const struct versatile_panel_type *panel_type;
0115     /**
0116      * @map: map to the parent syscon where the main register reside
0117      */
0118     struct regmap *map;
0119     /**
0120      * @ib2_map: map to the IB2 syscon, if applicable
0121      */
0122     struct regmap *ib2_map;
0123 };
0124
0125 static const struct versatile_panel_type versatile_panels[] = {
0126     /*
0127      * Sanyo TM38QV67A02A - 3.8 inch QVGA (320x240) Color TFT
0128      * found on the Versatile AB IB1 connector or the Versatile
0129      * PB adaptor board connector.
0130      */
0131     {
0132         .name = "Sanyo TM38QV67A02A",
0133         .magic = SYS_CLCD_ID_SANYO_3_8,
0134         .width_mm = 79,
0135         .height_mm = 54,
0136         .mode = {
0137             .clock = 10000,
0138             .hdisplay = 320,
0139             .hsync_start = 320 + 6,
0140             .hsync_end = 320 + 6 + 6,
0141             .htotal = 320 + 6 + 6 + 6,
0142             .vdisplay = 240,
0143             .vsync_start = 240 + 5,
0144             .vsync_end = 240 + 5 + 6,
0145             .vtotal = 240 + 5 + 6 + 5,
0146             .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
0147         },
0148     },
0149     /*
0150      * Sharp LQ084V1DG21 640x480 VGA Color TFT module
0151      * found on the Versatile AB IB1 connector or the Versatile
0152      * PB adaptor board connector.
0153      */
0154     {
0155         .name = "Sharp LQ084V1DG21",
0156         .magic = SYS_CLCD_ID_SHARP_8_4,
0157         .width_mm = 171,
0158         .height_mm = 130,
0159         .mode = {
0160             .clock = 25000,
0161             .hdisplay = 640,
0162             .hsync_start = 640 + 24,
0163             .hsync_end = 640 + 24 + 96,
0164             .htotal = 640 + 24 + 96 + 24,
0165             .vdisplay = 480,
0166             .vsync_start = 480 + 11,
0167             .vsync_end = 480 + 11 + 2,
0168             .vtotal = 480 + 11 + 2 + 32,
0169             .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
0170         },
0171     },
0172     /*
0173      * Epson L2F50113T00 - 2.2 inch QCIF 176x220 Color TFT
0174      * found on the Versatile PB adaptor board connector.
0175      */
0176     {
0177         .name = "Epson L2F50113T00",
0178         .magic = SYS_CLCD_ID_EPSON_2_2,
0179         .width_mm = 34,
0180         .height_mm = 45,
0181         .mode = {
0182             .clock = 62500,
0183             .hdisplay = 176,
0184             .hsync_start = 176 + 2,
0185             .hsync_end = 176 + 2 + 3,
0186             .htotal = 176 + 2 + 3 + 3,
0187             .vdisplay = 220,
0188             .vsync_start = 220 + 0,
0189             .vsync_end = 220 + 0 + 2,
0190             .vtotal = 220 + 0 + 2 + 1,
0191             .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
0192         },
0193         .bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
0194     },
0195     /*
0196      * Sanyo ALR252RGT 240x320 portrait display found on the
0197      * Versatile AB IB2 daughterboard for GSM prototyping.
0198      */
0199     {
0200         .name = "Sanyo ALR252RGT",
0201         .magic = SYS_CLCD_ID_SANYO_2_5,
0202         .width_mm = 37,
0203         .height_mm = 50,
0204         .mode = {
0205             .clock = 5400,
0206             .hdisplay = 240,
0207             .hsync_start = 240 + 10,
0208             .hsync_end = 240 + 10 + 10,
0209             .htotal = 240 + 10 + 10 + 20,
0210             .vdisplay = 320,
0211             .vsync_start = 320 + 2,
0212             .vsync_end = 320 + 2 + 2,
0213             .vtotal = 320 + 2 + 2 + 2,
0214             .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
0215         },
0216         .bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
0217         .ib2 = true,
0218     },
0219 };
0220
0221 static inline struct versatile_panel *
0222 to_versatile_panel(struct drm_panel *panel)
0223 {
0224     return container_of(panel, struct versatile_panel, panel);
0225 }
0226
0227 static int versatile_panel_disable(struct drm_panel *panel)
0228 {
0229     struct versatile_panel *vpanel = to_versatile_panel(panel);
0230
0231     /* If we're on an IB2 daughterboard, turn off display */
0232     if (vpanel->ib2_map) {
0233         dev_dbg(vpanel->dev, "disable IB2 display\n");
0234         regmap_update_bits(vpanel->ib2_map,
0235                    IB2_CTRL,
0236                    IB2_CTRL_LCD_MASK,
0237                    IB2_CTRL_LCD_SD);
0238     }
0239
0240     return 0;
0241 }
0242
0243 static int versatile_panel_enable(struct drm_panel *panel)
0244 {
0245     struct versatile_panel *vpanel = to_versatile_panel(panel);
0246
0247     /* If we're on an IB2 daughterboard, turn on display */
0248     if (vpanel->ib2_map) {
0249         dev_dbg(vpanel->dev, "enable IB2 display\n");
0250         regmap_update_bits(vpanel->ib2_map,
0251                    IB2_CTRL,
0252                    IB2_CTRL_LCD_MASK,
0253                    IB2_CTRL_LCD_BL_ON);
0254     }
0255
0256     return 0;
0257 }
0258
0259 static int versatile_panel_get_modes(struct drm_panel *panel,
0260                      struct drm_connector *connector)
0261 {
0262     struct versatile_panel *vpanel = to_versatile_panel(panel);
0263     struct drm_display_mode *mode;
0264
0265     connector->display_info.width_mm = vpanel->panel_type->width_mm;
0266     connector->display_info.height_mm = vpanel->panel_type->height_mm;
0267     connector->display_info.bus_flags = vpanel->panel_type->bus_flags;
0268
0269     mode = drm_mode_duplicate(connector->dev, &vpanel->panel_type->mode);
0270     drm_mode_set_name(mode);
0271     mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
0272
0273     mode->width_mm = vpanel->panel_type->width_mm;
0274     mode->height_mm = vpanel->panel_type->height_mm;
0275     drm_mode_probed_add(connector, mode);
0276
0277     return 1;
0278 }
0279
0280 static const struct drm_panel_funcs versatile_panel_drm_funcs = {
0281     .disable = versatile_panel_disable,
0282     .enable = versatile_panel_enable,
0283     .get_modes = versatile_panel_get_modes,
0284 };
0285
0286 static int versatile_panel_probe(struct platform_device *pdev)
0287 {
0288     struct device *dev = &pdev->dev;
0289     struct versatile_panel *vpanel;
0290     struct device *parent;
0291     struct regmap *map;
0292     int ret;
0293     u32 val;
0294     int i;
0295
0296     parent = dev->parent;
0297     if (!parent) {
0298         dev_err(dev, "no parent for versatile panel\n");
0299         return -ENODEV;
0300     }
0301     map = syscon_node_to_regmap(parent->of_node);
0302     if (IS_ERR(map)) {
0303         dev_err(dev, "no regmap for versatile panel parent\n");
0304         return PTR_ERR(map);
0305     }
0306
0307     vpanel = devm_kzalloc(dev, sizeof(*vpanel), GFP_KERNEL);
0308     if (!vpanel)
0309         return -ENOMEM;
0310
0311     ret = regmap_read(map, SYS_CLCD, &val);
0312     if (ret) {
0313         dev_err(dev, "cannot access syscon regs\n");
0314         return ret;
0315     }
0316
0317     val &= SYS_CLCD_CLCDID_MASK;
0318
0319     for (i = 0; i < ARRAY_SIZE(versatile_panels); i++) {
0320         const struct versatile_panel_type *pt;
0321
0322         pt = &versatile_panels[i];
0323         if (pt->magic == val) {
0324             vpanel->panel_type = pt;
0325             break;
0326         }
0327     }
0328
0329     /* No panel detected or VGA, let's leave this show */
0330     if (i == ARRAY_SIZE(versatile_panels)) {
0331         dev_info(dev, "no panel detected\n");
0332         return -ENODEV;
0333     }
0334
0335     dev_info(dev, "detected: %s\n", vpanel->panel_type->name);
0336     vpanel->dev = dev;
0337     vpanel->map = map;
0338
0339     /* Check if the panel is mounted on an IB2 daughterboard */
0340     if (vpanel->panel_type->ib2) {
0341         vpanel->ib2_map = syscon_regmap_lookup_by_compatible(
0342             "arm,versatile-ib2-syscon");
0343         if (IS_ERR(vpanel->ib2_map))
0344             vpanel->ib2_map = NULL;
0345         else
0346             dev_info(dev, "panel mounted on IB2 daughterboard\n");
0347     }
0348
0349     drm_panel_init(&vpanel->panel, dev, &versatile_panel_drm_funcs,
0350                DRM_MODE_CONNECTOR_DPI);
0351
0352     drm_panel_add(&vpanel->panel);
0353
0354     return 0;
0355 }
0356
0357 static const struct of_device_id versatile_panel_match[] = {
0358     { .compatible = "arm,versatile-tft-panel", },
0359     {},
0360 };
0361 MODULE_DEVICE_TABLE(of, versatile_panel_match);
0362
0363 static struct platform_driver versatile_panel_driver = {
0364     .probe      = versatile_panel_probe,
0365     .driver     = {
0366         .name   = "versatile-tft-panel",
0367         .of_match_table = versatile_panel_match,
0368     },
0369 };
0370 module_platform_driver(versatile_panel_driver);
0371
0372 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
0373 MODULE_DESCRIPTION("ARM Versatile panel driver");
0374 MODULE_LICENSE("GPL v2");