drivers/gpu/drm/aspeed/aspeed_gfx_drv.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 // Copyright 2018 IBM Corporation
   3
   4 #include <linux/clk.h>
   5 #include <linux/dma-mapping.h>
   6 #include <linux/irq.h>
   7 #include <linux/mfd/syscon.h>
   8 #include <linux/module.h>
   9 #include <linux/of.h>
  10 #include <linux/of_device.h>
  11 #include <linux/of_reserved_mem.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/regmap.h>
  14 #include <linux/reset.h>
  15
  16 #include <drm/drm_atomic_helper.h>
  17 #include <drm/drm_crtc_helper.h>
  18 #include <drm/drm_device.h>
  19 #include <drm/drm_fb_helper.h>
  20 #include <drm/drm_gem_dma_helper.h>
  21 #include <drm/drm_gem_framebuffer_helper.h>
  22 #include <drm/drm_module.h>
  23 #include <drm/drm_probe_helper.h>
  24 #include <drm/drm_simple_kms_helper.h>
  25 #include <drm/drm_vblank.h>
  26 #include <drm/drm_drv.h>
  27
  28 #include "aspeed_gfx.h"
  29
  30 /**
  31  * DOC: ASPEED GFX Driver
  32  *
  33  * This driver is for the ASPEED BMC SoC's 'GFX' display hardware, also called
  34  * the 'SOC Display Controller' in the datasheet. This driver runs on the ARM
  35  * based BMC systems, unlike the ast driver which runs on a host CPU and is for
  36  * a PCIe graphics device.
  37  *
  38  * The AST2500 supports a total of 3 output paths:
  39  *
  40  *   1. VGA output, the output target can choose either or both to the DAC
  41  *   or DVO interface.
  42  *
  43  *   2. Graphics CRT output, the output target can choose either or both to
  44  *   the DAC or DVO interface.
  45  *
  46  *   3. Video input from DVO, the video input can be used for video engine
  47  *   capture or DAC display output.
  48  *
  49  * Output options are selected in SCU2C.
  50  *
  51  * The "VGA mode" device is the PCI attached controller. The "Graphics CRT"
  52  * is the ARM's internal display controller.
  53  *
  54  * The driver only supports a simple configuration consisting of a 40MHz
  55  * pixel clock, fixed by hardware limitations, and the VGA output path.
  56  *
  57  * The driver was written with the 'AST2500 Software Programming Guide' v17,
  58  * which is available under NDA from ASPEED.
  59  */
  60
  61 struct aspeed_gfx_config {
  62         u32 dac_reg;            /* DAC register in SCU */
  63         u32 int_clear_reg;      /* Interrupt clear register */
  64         u32 vga_scratch_reg;    /* VGA scratch register in SCU */
  65         u32 throd_val;          /* Default Threshold Seting */
  66         u32 scan_line_max;      /* Max memory size of one scan line */
  67 };
  68
  69 static const struct aspeed_gfx_config ast2400_config = {
  70         .dac_reg = 0x2c,
  71         .int_clear_reg = 0x60,
  72         .vga_scratch_reg = 0x50,
  73         .throd_val = CRT_THROD_LOW(0x1e) | CRT_THROD_HIGH(0x12),
  74         .scan_line_max = 64,
  75 };
  76
  77 static const struct aspeed_gfx_config ast2500_config = {
  78         .dac_reg = 0x2c,
  79         .int_clear_reg = 0x60,
  80         .vga_scratch_reg = 0x50,
  81         .throd_val = CRT_THROD_LOW(0x24) | CRT_THROD_HIGH(0x3c),
  82         .scan_line_max = 128,
  83 };
  84
  85 static const struct aspeed_gfx_config ast2600_config = {
  86         .dac_reg = 0xc0,
  87         .int_clear_reg = 0x68,
  88         .vga_scratch_reg = 0x50,
  89         .throd_val = CRT_THROD_LOW(0x50) | CRT_THROD_HIGH(0x70),
  90         .scan_line_max = 128,
  91 };
  92
  93 static const struct of_device_id aspeed_gfx_match[] = {
  94         { .compatible = "aspeed,ast2400-gfx", .data = &ast2400_config },
  95         { .compatible = "aspeed,ast2500-gfx", .data = &ast2500_config },
  96         { .compatible = "aspeed,ast2600-gfx", .data = &ast2600_config },
  97         { },
  98 };
  99 MODULE_DEVICE_TABLE(of, aspeed_gfx_match);
 100
 101 static const struct drm_mode_config_funcs aspeed_gfx_mode_config_funcs = {
 102         .fb_create              = drm_gem_fb_create,
 103         .atomic_check           = drm_atomic_helper_check,
 104         .atomic_commit          = drm_atomic_helper_commit,
 105 };
 106
 107 static int aspeed_gfx_setup_mode_config(struct drm_device *drm)
 108 {
 109         int ret;
 110
 111         ret = drmm_mode_config_init(drm);
 112         if (ret)
 113                 return ret;
 114
 115         drm->mode_config.min_width = 0;
 116         drm->mode_config.min_height = 0;
 117         drm->mode_config.max_width = 800;
 118         drm->mode_config.max_height = 600;
 119         drm->mode_config.funcs = &aspeed_gfx_mode_config_funcs;
 120
 121         return ret;
 122 }
 123
 124 static irqreturn_t aspeed_gfx_irq_handler(int irq, void *data)
 125 {
 126         struct drm_device *drm = data;
 127         struct aspeed_gfx *priv = to_aspeed_gfx(drm);
 128         u32 reg;
 129
 130         reg = readl(priv->base + CRT_CTRL1);
 131
 132         if (reg & CRT_CTRL_VERTICAL_INTR_STS) {
 133                 drm_crtc_handle_vblank(&priv->pipe.crtc);
 134                 writel(reg, priv->base + priv->int_clr_reg);
 135                 return IRQ_HANDLED;
 136         }
 137
 138         return IRQ_NONE;
 139 }
 140
 141 static int aspeed_gfx_load(struct drm_device *drm)
 142 {
 143         struct platform_device *pdev = to_platform_device(drm->dev);
 144         struct aspeed_gfx *priv = to_aspeed_gfx(drm);
 145         struct device_node *np = pdev->dev.of_node;
 146         const struct aspeed_gfx_config *config;
 147         const struct of_device_id *match;
 148         struct resource *res;
 149         int ret;
 150
 151         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 152         priv->base = devm_ioremap_resource(drm->dev, res);
 153         if (IS_ERR(priv->base))
 154                 return PTR_ERR(priv->base);
 155
 156         match = of_match_device(aspeed_gfx_match, &pdev->dev);
 157         if (!match)
 158                 return -EINVAL;
 159         config = match->data;
 160
 161         priv->dac_reg = config->dac_reg;
 162         priv->int_clr_reg = config->int_clear_reg;
 163         priv->vga_scratch_reg = config->vga_scratch_reg;
 164         priv->throd_val = config->throd_val;
 165         priv->scan_line_max = config->scan_line_max;
 166
 167         priv->scu = syscon_regmap_lookup_by_phandle(np, "syscon");
 168         if (IS_ERR(priv->scu)) {
 169                 priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu");
 170                 if (IS_ERR(priv->scu)) {
 171                         dev_err(&pdev->dev, "failed to find SCU regmap\n");
 172                         return PTR_ERR(priv->scu);
 173                 }
 174         }
 175
 176         ret = of_reserved_mem_device_init(drm->dev);
 177         if (ret) {
 178                 dev_err(&pdev->dev,
 179                         "failed to initialize reserved mem: %d\n", ret);
 180                 return ret;
 181         }
 182
 183         ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32));
 184         if (ret) {
 185                 dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret);
 186                 return ret;
 187         }
 188
 189         priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 190         if (IS_ERR(priv->rst)) {
 191                 dev_err(&pdev->dev,
 192                         "missing or invalid reset controller device tree entry");
 193                 return PTR_ERR(priv->rst);
 194         }
 195         reset_control_deassert(priv->rst);
 196
 197         priv->clk = devm_clk_get(drm->dev, NULL);
 198         if (IS_ERR(priv->clk)) {
 199                 dev_err(&pdev->dev,
 200                         "missing or invalid clk device tree entry");
 201                 return PTR_ERR(priv->clk);
 202         }
 203         clk_prepare_enable(priv->clk);
 204
 205         /* Sanitize control registers */
 206         writel(0, priv->base + CRT_CTRL1);
 207         writel(0, priv->base + CRT_CTRL2);
 208
 209         ret = aspeed_gfx_setup_mode_config(drm);
 210         if (ret < 0)
 211                 return ret;
 212
 213         ret = drm_vblank_init(drm, 1);
 214         if (ret < 0) {
 215                 dev_err(drm->dev, "Failed to initialise vblank\n");
 216                 return ret;
 217         }
 218
 219         ret = aspeed_gfx_create_output(drm);
 220         if (ret < 0) {
 221                 dev_err(drm->dev, "Failed to create outputs\n");
 222                 return ret;
 223         }
 224
 225         ret = aspeed_gfx_create_pipe(drm);
 226         if (ret < 0) {
 227                 dev_err(drm->dev, "Cannot setup simple display pipe\n");
 228                 return ret;
 229         }
 230
 231         ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0),
 232                                aspeed_gfx_irq_handler, 0, "aspeed gfx", drm);
 233         if (ret < 0) {
 234                 dev_err(drm->dev, "Failed to install IRQ handler\n");
 235                 return ret;
 236         }
 237
 238         drm_mode_config_reset(drm);
 239
 240         return 0;
 241 }
 242
 243 static void aspeed_gfx_unload(struct drm_device *drm)
 244 {
 245         drm_kms_helper_poll_fini(drm);
 246 }
 247
 248 DEFINE_DRM_GEM_DMA_FOPS(fops);
 249
 250 static const struct drm_driver aspeed_gfx_driver = {
 251         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
 252         DRM_GEM_DMA_DRIVER_OPS,
 253         .fops = &fops,
 254         .name = "aspeed-gfx-drm",
 255         .desc = "ASPEED GFX DRM",
 256         .date = "20180319",
 257         .major = 1,
 258         .minor = 0,
 259 };
 260
 261 static ssize_t dac_mux_store(struct device *dev, struct device_attribute *attr,
 262                              const char *buf, size_t count)
 263 {
 264         struct aspeed_gfx *priv = dev_get_drvdata(dev);
 265         u32 val;
 266         int rc;
 267
 268         rc = kstrtou32(buf, 0, &val);
 269         if (rc)
 270                 return rc;
 271
 272         if (val > 3)
 273                 return -EINVAL;
 274
 275         rc = regmap_update_bits(priv->scu, priv->dac_reg, 0x30000, val << 16);
 276         if (rc < 0)
 277                 return 0;
 278
 279         return count;
 280 }
 281
 282 static ssize_t dac_mux_show(struct device *dev, struct device_attribute *attr, char *buf)
 283 {
 284         struct aspeed_gfx *priv = dev_get_drvdata(dev);
 285         u32 reg;
 286         int rc;
 287
 288         rc = regmap_read(priv->scu, priv->dac_reg, &reg);
 289         if (rc)
 290                 return rc;
 291
 292         return sprintf(buf, "%u\n", (reg >> 16) & 0x3);
 293 }
 294 static DEVICE_ATTR_RW(dac_mux);
 295
 296 static ssize_t
 297 vga_pw_show(struct device *dev, struct device_attribute *attr, char *buf)
 298 {
 299         struct aspeed_gfx *priv = dev_get_drvdata(dev);
 300         u32 reg;
 301         int rc;
 302
 303         rc = regmap_read(priv->scu, priv->vga_scratch_reg, &reg);
 304         if (rc)
 305                 return rc;
 306
 307         return sprintf(buf, "%u\n", reg);
 308 }
 309 static DEVICE_ATTR_RO(vga_pw);
 310
 311 static struct attribute *aspeed_sysfs_entries[] = {
 312         &dev_attr_vga_pw.attr,
 313         &dev_attr_dac_mux.attr,
 314         NULL,
 315 };
 316
 317 static struct attribute_group aspeed_sysfs_attr_group = {
 318         .attrs = aspeed_sysfs_entries,
 319 };
 320
 321 static int aspeed_gfx_probe(struct platform_device *pdev)
 322 {
 323         struct aspeed_gfx *priv;
 324         int ret;
 325
 326         priv = devm_drm_dev_alloc(&pdev->dev, &aspeed_gfx_driver,
 327                                   struct aspeed_gfx, drm);
 328         if (IS_ERR(priv))
 329                 return PTR_ERR(priv);
 330
 331         ret = aspeed_gfx_load(&priv->drm);
 332         if (ret)
 333                 return ret;
 334
 335         platform_set_drvdata(pdev, priv);
 336
 337         ret = sysfs_create_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
 338         if (ret)
 339                 return ret;
 340
 341         ret = drm_dev_register(&priv->drm, 0);
 342         if (ret)
 343                 goto err_unload;
 344
 345         drm_fbdev_generic_setup(&priv->drm, 32);
 346         return 0;
 347
 348 err_unload:
 349         sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
 350         aspeed_gfx_unload(&priv->drm);
 351
 352         return ret;
 353 }
 354
 355 static int aspeed_gfx_remove(struct platform_device *pdev)
 356 {
 357         struct drm_device *drm = platform_get_drvdata(pdev);
 358
 359         sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
 360         drm_dev_unregister(drm);
 361         aspeed_gfx_unload(drm);
 362
 363         return 0;
 364 }
 365
 366 static struct platform_driver aspeed_gfx_platform_driver = {
 367         .probe          = aspeed_gfx_probe,
 368         .remove         = aspeed_gfx_remove,
 369         .driver = {
 370                 .name = "aspeed_gfx",
 371                 .of_match_table = aspeed_gfx_match,
 372         },
 373 };
 374
 375 drm_module_platform_driver(aspeed_gfx_platform_driver);
 376
 377 MODULE_AUTHOR("Joel Stanley <[email protected]>");
 378 MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver");
 379 MODULE_LICENSE("GPL");