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