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_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 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         .vga_scratch_reg = 0x50,
  71         .throd_val = CRT_THROD_LOW(0x1e) | CRT_THROD_HIGH(0x12),
  72         .scan_line_max = 64,
  73 };
  74
  75 static const struct aspeed_gfx_config ast2500_config = {
  76         .dac_reg = 0x2c,
  77         .vga_scratch_reg = 0x50,
  78         .throd_val = CRT_THROD_LOW(0x24) | CRT_THROD_HIGH(0x3c),
  79         .scan_line_max = 128,
  80 };
  81
  82 static const struct of_device_id aspeed_gfx_match[] = {
  83         { .compatible = "aspeed,ast2400-gfx", .data = &ast2400_config },
  84         { .compatible = "aspeed,ast2500-gfx", .data = &ast2500_config },
  85         { },
  86 };
  87 MODULE_DEVICE_TABLE(of, aspeed_gfx_match);
  88
  89 static const struct drm_mode_config_funcs aspeed_gfx_mode_config_funcs = {
  90         .fb_create              = drm_gem_fb_create,
  91         .atomic_check           = drm_atomic_helper_check,
  92         .atomic_commit          = drm_atomic_helper_commit,
  93 };
  94
  95 static int aspeed_gfx_setup_mode_config(struct drm_device *drm)
  96 {
  97         int ret;
  98
  99         ret = drmm_mode_config_init(drm);
 100         if (ret)
 101                 return ret;
 102
 103         drm->mode_config.min_width = 0;
 104         drm->mode_config.min_height = 0;
 105         drm->mode_config.max_width = 800;
 106         drm->mode_config.max_height = 600;
 107         drm->mode_config.funcs = &aspeed_gfx_mode_config_funcs;
 108
 109         return ret;
 110 }
 111
 112 static irqreturn_t aspeed_gfx_irq_handler(int irq, void *data)
 113 {
 114         struct drm_device *drm = data;
 115         struct aspeed_gfx *priv = to_aspeed_gfx(drm);
 116         u32 reg;
 117
 118         reg = readl(priv->base + CRT_CTRL1);
 119
 120         if (reg & CRT_CTRL_VERTICAL_INTR_STS) {
 121                 drm_crtc_handle_vblank(&priv->pipe.crtc);
 122                 writel(reg, priv->base + CRT_CTRL1);
 123                 return IRQ_HANDLED;
 124         }
 125
 126         return IRQ_NONE;
 127 }
 128
 129 static int aspeed_gfx_load(struct drm_device *drm)
 130 {
 131         struct platform_device *pdev = to_platform_device(drm->dev);
 132         struct aspeed_gfx *priv = to_aspeed_gfx(drm);
 133         struct device_node *np = pdev->dev.of_node;
 134         const struct aspeed_gfx_config *config;
 135         const struct of_device_id *match;
 136         struct resource *res;
 137         int ret;
 138
 139         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 140         priv->base = devm_ioremap_resource(drm->dev, res);
 141         if (IS_ERR(priv->base))
 142                 return PTR_ERR(priv->base);
 143
 144         match = of_match_device(aspeed_gfx_match, &pdev->dev);
 145         if (!match)
 146                 return -EINVAL;
 147         config = match->data;
 148
 149         priv->dac_reg = config->dac_reg;
 150         priv->vga_scratch_reg = config->vga_scratch_reg;
 151         priv->throd_val = config->throd_val;
 152         priv->scan_line_max = config->scan_line_max;
 153
 154         priv->scu = syscon_regmap_lookup_by_phandle(np, "syscon");
 155         if (IS_ERR(priv->scu)) {
 156                 priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu");
 157                 if (IS_ERR(priv->scu)) {
 158                         dev_err(&pdev->dev, "failed to find SCU regmap\n");
 159                         return PTR_ERR(priv->scu);
 160                 }
 161         }
 162
 163         ret = of_reserved_mem_device_init(drm->dev);
 164         if (ret) {
 165                 dev_err(&pdev->dev,
 166                         "failed to initialize reserved mem: %d\n", ret);
 167                 return ret;
 168         }
 169
 170         ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32));
 171         if (ret) {
 172                 dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret);
 173                 return ret;
 174         }
 175
 176         priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 177         if (IS_ERR(priv->rst)) {
 178                 dev_err(&pdev->dev,
 179                         "missing or invalid reset controller device tree entry");
 180                 return PTR_ERR(priv->rst);
 181         }
 182         reset_control_deassert(priv->rst);
 183
 184         priv->clk = devm_clk_get(drm->dev, NULL);
 185         if (IS_ERR(priv->clk)) {
 186                 dev_err(&pdev->dev,
 187                         "missing or invalid clk device tree entry");
 188                 return PTR_ERR(priv->clk);
 189         }
 190         clk_prepare_enable(priv->clk);
 191
 192         /* Sanitize control registers */
 193         writel(0, priv->base + CRT_CTRL1);
 194         writel(0, priv->base + CRT_CTRL2);
 195
 196         ret = aspeed_gfx_setup_mode_config(drm);
 197         if (ret < 0)
 198                 return ret;
 199
 200         ret = drm_vblank_init(drm, 1);
 201         if (ret < 0) {
 202                 dev_err(drm->dev, "Failed to initialise vblank\n");
 203                 return ret;
 204         }
 205
 206         ret = aspeed_gfx_create_output(drm);
 207         if (ret < 0) {
 208                 dev_err(drm->dev, "Failed to create outputs\n");
 209                 return ret;
 210         }
 211
 212         ret = aspeed_gfx_create_pipe(drm);
 213         if (ret < 0) {
 214                 dev_err(drm->dev, "Cannot setup simple display pipe\n");
 215                 return ret;
 216         }
 217
 218         ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0),
 219                                aspeed_gfx_irq_handler, 0, "aspeed gfx", drm);
 220         if (ret < 0) {
 221                 dev_err(drm->dev, "Failed to install IRQ handler\n");
 222                 return ret;
 223         }
 224
 225         drm_mode_config_reset(drm);
 226
 227         return 0;
 228 }
 229
 230 static void aspeed_gfx_unload(struct drm_device *drm)
 231 {
 232         drm_kms_helper_poll_fini(drm);
 233 }
 234
 235 DEFINE_DRM_GEM_CMA_FOPS(fops);
 236
 237 static const struct drm_driver aspeed_gfx_driver = {
 238         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
 239         DRM_GEM_CMA_DRIVER_OPS,
 240         .fops = &fops,
 241         .name = "aspeed-gfx-drm",
 242         .desc = "ASPEED GFX DRM",
 243         .date = "20180319",
 244         .major = 1,
 245         .minor = 0,
 246 };
 247
 248 static ssize_t dac_mux_store(struct device *dev, struct device_attribute *attr,
 249                              const char *buf, size_t count)
 250 {
 251         struct aspeed_gfx *priv = dev_get_drvdata(dev);
 252         u32 val;
 253         int rc;
 254
 255         rc = kstrtou32(buf, 0, &val);
 256         if (rc)
 257                 return rc;
 258
 259         if (val > 3)
 260                 return -EINVAL;
 261
 262         rc = regmap_update_bits(priv->scu, priv->dac_reg, 0x30000, val << 16);
 263         if (rc < 0)
 264                 return 0;
 265
 266         return count;
 267 }
 268
 269 static ssize_t dac_mux_show(struct device *dev, struct device_attribute *attr, char *buf)
 270 {
 271         struct aspeed_gfx *priv = dev_get_drvdata(dev);
 272         u32 reg;
 273         int rc;
 274
 275         rc = regmap_read(priv->scu, priv->dac_reg, &reg);
 276         if (rc)
 277                 return rc;
 278
 279         return sprintf(buf, "%u\n", (reg >> 16) & 0x3);
 280 }
 281 static DEVICE_ATTR_RW(dac_mux);
 282
 283 static ssize_t
 284 vga_pw_show(struct device *dev, struct device_attribute *attr, char *buf)
 285 {
 286         struct aspeed_gfx *priv = dev_get_drvdata(dev);
 287         u32 reg;
 288         int rc;
 289
 290         rc = regmap_read(priv->scu, priv->vga_scratch_reg, &reg);
 291         if (rc)
 292                 return rc;
 293
 294         return sprintf(buf, "%u\n", reg & 1);
 295 }
 296 static DEVICE_ATTR_RO(vga_pw);
 297
 298 static struct attribute *aspeed_sysfs_entries[] = {
 299         &dev_attr_vga_pw.attr,
 300         &dev_attr_dac_mux.attr,
 301         NULL,
 302 };
 303
 304 static struct attribute_group aspeed_sysfs_attr_group = {
 305         .attrs = aspeed_sysfs_entries,
 306 };
 307
 308 static int aspeed_gfx_probe(struct platform_device *pdev)
 309 {
 310         struct aspeed_gfx *priv;
 311         int ret;
 312
 313         priv = devm_drm_dev_alloc(&pdev->dev, &aspeed_gfx_driver,
 314                                   struct aspeed_gfx, drm);
 315         if (IS_ERR(priv))
 316                 return PTR_ERR(priv);
 317
 318         ret = aspeed_gfx_load(&priv->drm);
 319         if (ret)
 320                 return ret;
 321
 322         platform_set_drvdata(pdev, priv);
 323
 324         ret = sysfs_create_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
 325         if (ret)
 326                 return ret;
 327
 328         ret = drm_dev_register(&priv->drm, 0);
 329         if (ret)
 330                 goto err_unload;
 331
 332         drm_fbdev_generic_setup(&priv->drm, 32);
 333         return 0;
 334
 335 err_unload:
 336         sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
 337         aspeed_gfx_unload(&priv->drm);
 338
 339         return ret;
 340 }
 341
 342 static int aspeed_gfx_remove(struct platform_device *pdev)
 343 {
 344         struct drm_device *drm = platform_get_drvdata(pdev);
 345
 346         sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
 347         drm_dev_unregister(drm);
 348         aspeed_gfx_unload(drm);
 349
 350         return 0;
 351 }
 352
 353 static struct platform_driver aspeed_gfx_platform_driver = {
 354         .probe          = aspeed_gfx_probe,
 355         .remove         = aspeed_gfx_remove,
 356         .driver = {
 357                 .name = "aspeed_gfx",
 358                 .of_match_table = aspeed_gfx_match,
 359         },
 360 };
 361
 362 module_platform_driver(aspeed_gfx_platform_driver);
 363
 364 MODULE_AUTHOR("Joel Stanley <[email protected]>");
 365 MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver");
 366 MODULE_LICENSE("GPL");