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_reserved_mem.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/regmap.h>
  13 #include <linux/reset.h>
  14
  15 #include <drm/drm_atomic_helper.h>
  16 #include <drm/drm_crtc_helper.h>
  17 #include <drm/drm_device.h>
  18 #include <drm/drm_fb_cma_helper.h>
  19 #include <drm/drm_fb_helper.h>
  20 #include <drm/drm_gem_cma_helper.h>
  21 #include <drm/drm_gem_framebuffer_helper.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 static const struct drm_mode_config_funcs aspeed_gfx_mode_config_funcs = {
  61         .fb_create              = drm_gem_fb_create,
  62         .atomic_check           = drm_atomic_helper_check,
  63         .atomic_commit          = drm_atomic_helper_commit,
  64 };
  65
  66 static int aspeed_gfx_setup_mode_config(struct drm_device *drm)
  67 {
  68         int ret;
  69
  70         ret = drmm_mode_config_init(drm);
  71         if (ret)
  72                 return ret;
  73
  74         drm->mode_config.min_width = 0;
  75         drm->mode_config.min_height = 0;
  76         drm->mode_config.max_width = 800;
  77         drm->mode_config.max_height = 600;
  78         drm->mode_config.funcs = &aspeed_gfx_mode_config_funcs;
  79
  80         return ret;
  81 }
  82
  83 static irqreturn_t aspeed_gfx_irq_handler(int irq, void *data)
  84 {
  85         struct drm_device *drm = data;
  86         struct aspeed_gfx *priv = to_aspeed_gfx(drm);
  87         u32 reg;
  88
  89         reg = readl(priv->base + CRT_CTRL1);
  90
  91         if (reg & CRT_CTRL_VERTICAL_INTR_STS) {
  92                 drm_crtc_handle_vblank(&priv->pipe.crtc);
  93                 writel(reg, priv->base + CRT_CTRL1);
  94                 return IRQ_HANDLED;
  95         }
  96
  97         return IRQ_NONE;
  98 }
  99
 100
 101
 102 static int aspeed_gfx_load(struct drm_device *drm)
 103 {
 104         struct platform_device *pdev = to_platform_device(drm->dev);
 105         struct aspeed_gfx *priv = to_aspeed_gfx(drm);
 106         struct resource *res;
 107         int ret;
 108
 109         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 110         priv->base = devm_ioremap_resource(drm->dev, res);
 111         if (IS_ERR(priv->base))
 112                 return PTR_ERR(priv->base);
 113
 114         priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu");
 115         if (IS_ERR(priv->scu)) {
 116                 dev_err(&pdev->dev, "failed to find SCU regmap\n");
 117                 return PTR_ERR(priv->scu);
 118         }
 119
 120         ret = of_reserved_mem_device_init(drm->dev);
 121         if (ret) {
 122                 dev_err(&pdev->dev,
 123                         "failed to initialize reserved mem: %d\n", ret);
 124                 return ret;
 125         }
 126
 127         ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32));
 128         if (ret) {
 129                 dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret);
 130                 return ret;
 131         }
 132
 133         priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 134         if (IS_ERR(priv->rst)) {
 135                 dev_err(&pdev->dev,
 136                         "missing or invalid reset controller device tree entry");
 137                 return PTR_ERR(priv->rst);
 138         }
 139         reset_control_deassert(priv->rst);
 140
 141         priv->clk = devm_clk_get(drm->dev, NULL);
 142         if (IS_ERR(priv->clk)) {
 143                 dev_err(&pdev->dev,
 144                         "missing or invalid clk device tree entry");
 145                 return PTR_ERR(priv->clk);
 146         }
 147         clk_prepare_enable(priv->clk);
 148
 149         /* Sanitize control registers */
 150         writel(0, priv->base + CRT_CTRL1);
 151         writel(0, priv->base + CRT_CTRL2);
 152
 153         ret = aspeed_gfx_setup_mode_config(drm);
 154         if (ret < 0)
 155                 return ret;
 156
 157         ret = drm_vblank_init(drm, 1);
 158         if (ret < 0) {
 159                 dev_err(drm->dev, "Failed to initialise vblank\n");
 160                 return ret;
 161         }
 162
 163         ret = aspeed_gfx_create_output(drm);
 164         if (ret < 0) {
 165                 dev_err(drm->dev, "Failed to create outputs\n");
 166                 return ret;
 167         }
 168
 169         ret = aspeed_gfx_create_pipe(drm);
 170         if (ret < 0) {
 171                 dev_err(drm->dev, "Cannot setup simple display pipe\n");
 172                 return ret;
 173         }
 174
 175         ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0),
 176                                aspeed_gfx_irq_handler, 0, "aspeed gfx", drm);
 177         if (ret < 0) {
 178                 dev_err(drm->dev, "Failed to install IRQ handler\n");
 179                 return ret;
 180         }
 181
 182         drm_mode_config_reset(drm);
 183
 184         return 0;
 185 }
 186
 187 static void aspeed_gfx_unload(struct drm_device *drm)
 188 {
 189         drm_kms_helper_poll_fini(drm);
 190 }
 191
 192 DEFINE_DRM_GEM_CMA_FOPS(fops);
 193
 194 static const struct drm_driver aspeed_gfx_driver = {
 195         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
 196         DRM_GEM_CMA_DRIVER_OPS,
 197         .fops = &fops,
 198         .name = "aspeed-gfx-drm",
 199         .desc = "ASPEED GFX DRM",
 200         .date = "20180319",
 201         .major = 1,
 202         .minor = 0,
 203 };
 204
 205 static const struct of_device_id aspeed_gfx_match[] = {
 206         { .compatible = "aspeed,ast2500-gfx" },
 207         { }
 208 };
 209
 210 #define ASPEED_SCU_VGA0         0x50
 211 #define ASPEED_SCU_MISC_CTRL    0x2c
 212
 213 static ssize_t dac_mux_store(struct device *dev, struct device_attribute *attr,
 214                              const char *buf, size_t count)
 215 {
 216         struct aspeed_gfx *priv = dev_get_drvdata(dev);
 217         u32 val;
 218         int rc;
 219
 220         rc = kstrtou32(buf, 0, &val);
 221         if (rc)
 222                 return rc;
 223
 224         if (val > 3)
 225                 return -EINVAL;
 226
 227         rc = regmap_update_bits(priv->scu, ASPEED_SCU_MISC_CTRL, 0x30000, val << 16);
 228         if (rc < 0)
 229                 return 0;
 230
 231         return count;
 232 }
 233
 234 static ssize_t dac_mux_show(struct device *dev, struct device_attribute *attr, char *buf)
 235 {
 236         struct aspeed_gfx *priv = dev_get_drvdata(dev);
 237         u32 reg;
 238         int rc;
 239
 240         rc = regmap_read(priv->scu, ASPEED_SCU_MISC_CTRL, &reg);
 241         if (rc)
 242                 return rc;
 243
 244         return sprintf(buf, "%u\n", (reg >> 16) & 0x3);
 245 }
 246 static DEVICE_ATTR_RW(dac_mux);
 247
 248 static ssize_t
 249 vga_pw_show(struct device *dev, struct device_attribute *attr, char *buf)
 250 {
 251         struct aspeed_gfx *priv = dev_get_drvdata(dev);
 252         u32 reg;
 253         int rc;
 254
 255         rc = regmap_read(priv->scu, ASPEED_SCU_VGA0, &reg);
 256         if (rc)
 257                 return rc;
 258
 259         return sprintf(buf, "%u\n", reg & 1);
 260 }
 261 static DEVICE_ATTR_RO(vga_pw);
 262
 263 static struct attribute *aspeed_sysfs_entries[] = {
 264         &dev_attr_vga_pw.attr,
 265         &dev_attr_dac_mux.attr,
 266         NULL,
 267 };
 268
 269 static struct attribute_group aspeed_sysfs_attr_group = {
 270         .attrs = aspeed_sysfs_entries,
 271 };
 272
 273 static int aspeed_gfx_probe(struct platform_device *pdev)
 274 {
 275         struct aspeed_gfx *priv;
 276         int ret;
 277
 278         priv = devm_drm_dev_alloc(&pdev->dev, &aspeed_gfx_driver,
 279                                   struct aspeed_gfx, drm);
 280         if (IS_ERR(priv))
 281                 return PTR_ERR(priv);
 282
 283         ret = aspeed_gfx_load(&priv->drm);
 284         if (ret)
 285                 return ret;
 286
 287         dev_set_drvdata(&pdev->dev, priv);
 288
 289         ret = sysfs_create_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
 290         if (ret)
 291                 return ret;
 292
 293         ret = drm_dev_register(&priv->drm, 0);
 294         if (ret)
 295                 goto err_unload;
 296
 297         drm_fbdev_generic_setup(&priv->drm, 32);
 298         return 0;
 299
 300 err_unload:
 301         sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
 302         aspeed_gfx_unload(&priv->drm);
 303
 304         return ret;
 305 }
 306
 307 static int aspeed_gfx_remove(struct platform_device *pdev)
 308 {
 309         struct drm_device *drm = platform_get_drvdata(pdev);
 310
 311         sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
 312         drm_dev_unregister(drm);
 313         aspeed_gfx_unload(drm);
 314
 315         return 0;
 316 }
 317
 318 static struct platform_driver aspeed_gfx_platform_driver = {
 319         .probe          = aspeed_gfx_probe,
 320         .remove         = aspeed_gfx_remove,
 321         .driver = {
 322                 .name = "aspeed_gfx",
 323                 .of_match_table = aspeed_gfx_match,
 324         },
 325 };
 326
 327 module_platform_driver(aspeed_gfx_platform_driver);
 328
 329 MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");
 330 MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver");
 331 MODULE_LICENSE("GPL");