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_client_setup.h> 18 #include <drm/drm_device.h> 19 #include <drm/drm_fbdev_dma.h> 20 #include <drm/drm_gem_dma_helper.h> 21 #include <drm/drm_gem_framebuffer_helper.h> 22 #include <drm/drm_module.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 int_clear_reg; /* Interrupt clear register */ 64 u32 vga_scratch_reg; /* VGA scratch register in SCU */ 65 u32 throd_val; /* Default Threshold Seting */ 66 u32 scan_line_max; /* Max memory size of one scan line */ 67 }; 68 69 static const struct aspeed_gfx_config ast2400_config = { 70 .dac_reg = 0x2c, 71 .int_clear_reg = 0x60, 72 .vga_scratch_reg = 0x50, 73 .throd_val = CRT_THROD_LOW(0x1e) | CRT_THROD_HIGH(0x12), 74 .scan_line_max = 64, 75 }; 76 77 static const struct aspeed_gfx_config ast2500_config = { 78 .dac_reg = 0x2c, 79 .int_clear_reg = 0x60, 80 .vga_scratch_reg = 0x50, 81 .throd_val = CRT_THROD_LOW(0x24) | CRT_THROD_HIGH(0x3c), 82 .scan_line_max = 128, 83 }; 84 85 static const struct aspeed_gfx_config ast2600_config = { 86 .dac_reg = 0xc0, 87 .int_clear_reg = 0x68, 88 .vga_scratch_reg = 0x50, 89 .throd_val = CRT_THROD_LOW(0x50) | CRT_THROD_HIGH(0x70), 90 .scan_line_max = 128, 91 }; 92 93 static const struct of_device_id aspeed_gfx_match[] = { 94 { .compatible = "aspeed,ast2400-gfx", .data = &ast2400_config }, 95 { .compatible = "aspeed,ast2500-gfx", .data = &ast2500_config }, 96 { .compatible = "aspeed,ast2600-gfx", .data = &ast2600_config }, 97 { }, 98 }; 99 MODULE_DEVICE_TABLE(of, aspeed_gfx_match); 100 101 static const struct drm_mode_config_funcs aspeed_gfx_mode_config_funcs = { 102 .fb_create = drm_gem_fb_create, 103 .atomic_check = drm_atomic_helper_check, 104 .atomic_commit = drm_atomic_helper_commit, 105 }; 106 107 static int aspeed_gfx_setup_mode_config(struct drm_device *drm) 108 { 109 int ret; 110 111 ret = drmm_mode_config_init(drm); 112 if (ret) 113 return ret; 114 115 drm->mode_config.min_width = 0; 116 drm->mode_config.min_height = 0; 117 drm->mode_config.max_width = 800; 118 drm->mode_config.max_height = 600; 119 drm->mode_config.funcs = &aspeed_gfx_mode_config_funcs; 120 121 return ret; 122 } 123 124 static irqreturn_t aspeed_gfx_irq_handler(int irq, void *data) 125 { 126 struct drm_device *drm = data; 127 struct aspeed_gfx *priv = to_aspeed_gfx(drm); 128 u32 reg; 129 130 reg = readl(priv->base + CRT_CTRL1); 131 132 if (reg & CRT_CTRL_VERTICAL_INTR_STS) { 133 drm_crtc_handle_vblank(&priv->pipe.crtc); 134 writel(reg, priv->base + priv->int_clr_reg); 135 return IRQ_HANDLED; 136 } 137 138 return IRQ_NONE; 139 } 140 141 static int aspeed_gfx_load(struct drm_device *drm) 142 { 143 struct platform_device *pdev = to_platform_device(drm->dev); 144 struct aspeed_gfx *priv = to_aspeed_gfx(drm); 145 struct device_node *np = pdev->dev.of_node; 146 const struct aspeed_gfx_config *config; 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 config = device_get_match_data(&pdev->dev); 156 if (!config) 157 return -EINVAL; 158 159 priv->dac_reg = config->dac_reg; 160 priv->int_clr_reg = config->int_clear_reg; 161 priv->vga_scratch_reg = config->vga_scratch_reg; 162 priv->throd_val = config->throd_val; 163 priv->scan_line_max = config->scan_line_max; 164 165 priv->scu = syscon_regmap_lookup_by_phandle(np, "syscon"); 166 if (IS_ERR(priv->scu)) { 167 priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu"); 168 if (IS_ERR(priv->scu)) { 169 dev_err(&pdev->dev, "failed to find SCU regmap\n"); 170 return PTR_ERR(priv->scu); 171 } 172 } 173 174 ret = of_reserved_mem_device_init(drm->dev); 175 if (ret) { 176 dev_err(&pdev->dev, 177 "failed to initialize reserved mem: %d\n", ret); 178 return ret; 179 } 180 181 ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32)); 182 if (ret) { 183 dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret); 184 return ret; 185 } 186 187 priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); 188 if (IS_ERR(priv->rst)) { 189 dev_err(&pdev->dev, 190 "missing or invalid reset controller device tree entry"); 191 return PTR_ERR(priv->rst); 192 } 193 reset_control_deassert(priv->rst); 194 195 priv->clk = devm_clk_get(drm->dev, NULL); 196 if (IS_ERR(priv->clk)) { 197 dev_err(&pdev->dev, 198 "missing or invalid clk device tree entry"); 199 return PTR_ERR(priv->clk); 200 } 201 clk_prepare_enable(priv->clk); 202 203 /* Sanitize control registers */ 204 writel(0, priv->base + CRT_CTRL1); 205 writel(0, priv->base + CRT_CTRL2); 206 207 ret = aspeed_gfx_setup_mode_config(drm); 208 if (ret < 0) 209 return ret; 210 211 ret = drm_vblank_init(drm, 1); 212 if (ret < 0) { 213 dev_err(drm->dev, "Failed to initialise vblank\n"); 214 return ret; 215 } 216 217 ret = aspeed_gfx_create_output(drm); 218 if (ret < 0) { 219 dev_err(drm->dev, "Failed to create outputs\n"); 220 return ret; 221 } 222 223 ret = aspeed_gfx_create_pipe(drm); 224 if (ret < 0) { 225 dev_err(drm->dev, "Cannot setup simple display pipe\n"); 226 return ret; 227 } 228 229 ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0), 230 aspeed_gfx_irq_handler, 0, "aspeed gfx", drm); 231 if (ret < 0) { 232 dev_err(drm->dev, "Failed to install IRQ handler\n"); 233 return ret; 234 } 235 236 drm_mode_config_reset(drm); 237 238 return 0; 239 } 240 241 static void aspeed_gfx_unload(struct drm_device *drm) 242 { 243 drm_kms_helper_poll_fini(drm); 244 } 245 246 DEFINE_DRM_GEM_DMA_FOPS(fops); 247 248 static const struct drm_driver aspeed_gfx_driver = { 249 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 250 DRM_GEM_DMA_DRIVER_OPS, 251 DRM_FBDEV_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, ®); 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, ®); 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_client_setup(&priv->drm, NULL); 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 void 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 drm_atomic_helper_shutdown(drm); 362 } 363 364 static void aspeed_gfx_shutdown(struct platform_device *pdev) 365 { 366 drm_atomic_helper_shutdown(platform_get_drvdata(pdev)); 367 } 368 369 static struct platform_driver aspeed_gfx_platform_driver = { 370 .probe = aspeed_gfx_probe, 371 .remove = aspeed_gfx_remove, 372 .shutdown = aspeed_gfx_shutdown, 373 .driver = { 374 .name = "aspeed_gfx", 375 .of_match_table = aspeed_gfx_match, 376 }, 377 }; 378 379 drm_module_platform_driver(aspeed_gfx_platform_driver); 380 381 MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>"); 382 MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver"); 383 MODULE_LICENSE("GPL"); 384