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