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_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         const struct of_device_id *match;
 147         struct resource *res;
 148         int ret;
 149
 150         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 151         priv->base = devm_ioremap_resource(drm->dev, res);
 152         if (IS_ERR(priv->base))
 153                 return PTR_ERR(priv->base);
 154
 155         match = of_match_device(aspeed_gfx_match, &pdev->dev);
 156         if (!match)
 157                 return -EINVAL;
 158         config = match->data;
 159
 160         priv->dac_reg = config->dac_reg;
 161         priv->int_clr_reg = config->int_clear_reg;
 162         priv->vga_scratch_reg = config->vga_scratch_reg;
 163         priv->throd_val = config->throd_val;
 164         priv->scan_line_max = config->scan_line_max;
 165
 166         priv->scu = syscon_regmap_lookup_by_phandle(np, "syscon");
 167         if (IS_ERR(priv->scu)) {
 168                 priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu");
 169                 if (IS_ERR(priv->scu)) {
 170                         dev_err(&pdev->dev, "failed to find SCU regmap\n");
 171                         return PTR_ERR(priv->scu);
 172                 }
 173         }
 174
 175         ret = of_reserved_mem_device_init(drm->dev);
 176         if (ret) {
 177                 dev_err(&pdev->dev,
 178                         "failed to initialize reserved mem: %d\n", ret);
 179                 return ret;
 180         }
 181
 182         ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32));
 183         if (ret) {
 184                 dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret);
 185                 return ret;
 186         }
 187
 188         priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 189         if (IS_ERR(priv->rst)) {
 190                 dev_err(&pdev->dev,
 191                         "missing or invalid reset controller device tree entry");
 192                 return PTR_ERR(priv->rst);
 193         }
 194         reset_control_deassert(priv->rst);
 195
 196         priv->clk = devm_clk_get(drm->dev, NULL);
 197         if (IS_ERR(priv->clk)) {
 198                 dev_err(&pdev->dev,
 199                         "missing or invalid clk device tree entry");
 200                 return PTR_ERR(priv->clk);
 201         }
 202         clk_prepare_enable(priv->clk);
 203
 204         /* Sanitize control registers */
 205         writel(0, priv->base + CRT_CTRL1);
 206         writel(0, priv->base + CRT_CTRL2);
 207
 208         ret = aspeed_gfx_setup_mode_config(drm);
 209         if (ret < 0)
 210                 return ret;
 211
 212         ret = drm_vblank_init(drm, 1);
 213         if (ret < 0) {
 214                 dev_err(drm->dev, "Failed to initialise vblank\n");
 215                 return ret;
 216         }
 217
 218         ret = aspeed_gfx_create_output(drm);
 219         if (ret < 0) {
 220                 dev_err(drm->dev, "Failed to create outputs\n");
 221                 return ret;
 222         }
 223
 224         ret = aspeed_gfx_create_pipe(drm);
 225         if (ret < 0) {
 226                 dev_err(drm->dev, "Cannot setup simple display pipe\n");
 227                 return ret;
 228         }
 229
 230         ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0),
 231                                aspeed_gfx_irq_handler, 0, "aspeed gfx", drm);
 232         if (ret < 0) {
 233                 dev_err(drm->dev, "Failed to install IRQ handler\n");
 234                 return ret;
 235         }
 236
 237         drm_mode_config_reset(drm);
 238
 239         return 0;
 240 }
 241
 242 static void aspeed_gfx_unload(struct drm_device *drm)
 243 {
 244         drm_kms_helper_poll_fini(drm);
 245 }
 246
 247 DEFINE_DRM_GEM_DMA_FOPS(fops);
 248
 249 static const struct drm_driver aspeed_gfx_driver = {
 250         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
 251         DRM_GEM_DMA_DRIVER_OPS,
 252         .fops = &fops,
 253         .name = "aspeed-gfx-drm",
 254         .desc = "ASPEED GFX DRM",
 255         .date = "20180319",
 256         .major = 1,
 257         .minor = 0,
 258 };
 259
 260 static ssize_t dac_mux_store(struct device *dev, struct device_attribute *attr,
 261                              const char *buf, size_t count)
 262 {
 263         struct aspeed_gfx *priv = dev_get_drvdata(dev);
 264         u32 val;
 265         int rc;
 266
 267         rc = kstrtou32(buf, 0, &val);
 268         if (rc)
 269                 return rc;
 270
 271         if (val > 3)
 272                 return -EINVAL;
 273
 274         rc = regmap_update_bits(priv->scu, priv->dac_reg, 0x30000, val << 16);
 275         if (rc < 0)
 276                 return 0;
 277
 278         return count;
 279 }
 280
 281 static ssize_t dac_mux_show(struct device *dev, struct device_attribute *attr, char *buf)
 282 {
 283         struct aspeed_gfx *priv = dev_get_drvdata(dev);
 284         u32 reg;
 285         int rc;
 286
 287         rc = regmap_read(priv->scu, priv->dac_reg, &reg);
 288         if (rc)
 289                 return rc;
 290
 291         return sprintf(buf, "%u\n", (reg >> 16) & 0x3);
 292 }
 293 static DEVICE_ATTR_RW(dac_mux);
 294
 295 static ssize_t
 296 vga_pw_show(struct device *dev, struct device_attribute *attr, char *buf)
 297 {
 298         struct aspeed_gfx *priv = dev_get_drvdata(dev);
 299         u32 reg;
 300         int rc;
 301
 302         rc = regmap_read(priv->scu, priv->vga_scratch_reg, &reg);
 303         if (rc)
 304                 return rc;
 305
 306         return sprintf(buf, "%u\n", reg);
 307 }
 308 static DEVICE_ATTR_RO(vga_pw);
 309
 310 static struct attribute *aspeed_sysfs_entries[] = {
 311         &dev_attr_vga_pw.attr,
 312         &dev_attr_dac_mux.attr,
 313         NULL,
 314 };
 315
 316 static struct attribute_group aspeed_sysfs_attr_group = {
 317         .attrs = aspeed_sysfs_entries,
 318 };
 319
 320 static int aspeed_gfx_probe(struct platform_device *pdev)
 321 {
 322         struct aspeed_gfx *priv;
 323         int ret;
 324
 325         priv = devm_drm_dev_alloc(&pdev->dev, &aspeed_gfx_driver,
 326                                   struct aspeed_gfx, drm);
 327         if (IS_ERR(priv))
 328                 return PTR_ERR(priv);
 329
 330         ret = aspeed_gfx_load(&priv->drm);
 331         if (ret)
 332                 return ret;
 333
 334         platform_set_drvdata(pdev, priv);
 335
 336         ret = sysfs_create_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
 337         if (ret)
 338                 return ret;
 339
 340         ret = drm_dev_register(&priv->drm, 0);
 341         if (ret)
 342                 goto err_unload;
 343
 344         drm_fbdev_dma_setup(&priv->drm, 32);
 345         return 0;
 346
 347 err_unload:
 348         sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
 349         aspeed_gfx_unload(&priv->drm);
 350
 351         return ret;
 352 }
 353
 354 static int aspeed_gfx_remove(struct platform_device *pdev)
 355 {
 356         struct drm_device *drm = platform_get_drvdata(pdev);
 357
 358         sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
 359         drm_dev_unregister(drm);
 360         aspeed_gfx_unload(drm);
 361
 362         return 0;
 363 }
 364
 365 static struct platform_driver aspeed_gfx_platform_driver = {
 366         .probe          = aspeed_gfx_probe,
 367         .remove         = aspeed_gfx_remove,
 368         .driver = {
 369                 .name = "aspeed_gfx",
 370                 .of_match_table = aspeed_gfx_match,
 371         },
 372 };
 373
 374 drm_module_platform_driver(aspeed_gfx_platform_driver);
 375
 376 MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");
 377 MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver");
 378 MODULE_LICENSE("GPL");