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_reserved_mem.h> 10 #include <linux/platform_device.h> 11 #include <linux/property.h> 12 #include <linux/regmap.h> 13 #include <linux/reset.h> 14 15 #include <drm/clients/drm_client_setup.h> 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 int ret; 147 148 priv->base = devm_platform_ioremap_resource(pdev, 0); 149 if (IS_ERR(priv->base)) 150 return PTR_ERR(priv->base); 151 152 config = device_get_match_data(&pdev->dev); 153 if (!config) 154 return -EINVAL; 155 156 priv->dac_reg = config->dac_reg; 157 priv->int_clr_reg = config->int_clear_reg; 158 priv->vga_scratch_reg = config->vga_scratch_reg; 159 priv->throd_val = config->throd_val; 160 priv->scan_line_max = config->scan_line_max; 161 162 priv->scu = syscon_regmap_lookup_by_phandle(np, "syscon"); 163 if (IS_ERR(priv->scu)) { 164 priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu"); 165 if (IS_ERR(priv->scu)) { 166 dev_err(&pdev->dev, "failed to find SCU regmap\n"); 167 return PTR_ERR(priv->scu); 168 } 169 } 170 171 ret = of_reserved_mem_device_init(drm->dev); 172 if (ret) { 173 dev_err(&pdev->dev, 174 "failed to initialize reserved mem: %d\n", ret); 175 return ret; 176 } 177 178 ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32)); 179 if (ret) { 180 dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret); 181 return ret; 182 } 183 184 priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); 185 if (IS_ERR(priv->rst)) { 186 dev_err(&pdev->dev, 187 "missing or invalid reset controller device tree entry"); 188 return PTR_ERR(priv->rst); 189 } 190 reset_control_deassert(priv->rst); 191 192 priv->clk = devm_clk_get_enabled(drm->dev, NULL); 193 if (IS_ERR(priv->clk)) { 194 dev_err(&pdev->dev, 195 "failed to get and enable clock\n"); 196 return PTR_ERR(priv->clk); 197 } 198 199 /* Sanitize control registers */ 200 writel(0, priv->base + CRT_CTRL1); 201 writel(0, priv->base + CRT_CTRL2); 202 203 ret = aspeed_gfx_setup_mode_config(drm); 204 if (ret < 0) 205 return ret; 206 207 ret = drm_vblank_init(drm, 1); 208 if (ret < 0) { 209 dev_err(drm->dev, "Failed to initialise vblank\n"); 210 return ret; 211 } 212 213 ret = aspeed_gfx_create_output(drm); 214 if (ret < 0) { 215 dev_err(drm->dev, "Failed to create outputs\n"); 216 return ret; 217 } 218 219 ret = aspeed_gfx_create_pipe(drm); 220 if (ret < 0) { 221 dev_err(drm->dev, "Cannot setup simple display pipe\n"); 222 return ret; 223 } 224 225 ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0), 226 aspeed_gfx_irq_handler, 0, "aspeed gfx", drm); 227 if (ret < 0) { 228 dev_err(drm->dev, "Failed to install IRQ handler\n"); 229 return ret; 230 } 231 232 drm_mode_config_reset(drm); 233 234 return 0; 235 } 236 237 static void aspeed_gfx_unload(struct drm_device *drm) 238 { 239 drm_kms_helper_poll_fini(drm); 240 } 241 242 DEFINE_DRM_GEM_DMA_FOPS(fops); 243 244 static const struct drm_driver aspeed_gfx_driver = { 245 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 246 DRM_GEM_DMA_DRIVER_OPS, 247 DRM_FBDEV_DMA_DRIVER_OPS, 248 .fops = &fops, 249 .name = "aspeed-gfx-drm", 250 .desc = "ASPEED GFX DRM", 251 .major = 1, 252 .minor = 0, 253 }; 254 255 static ssize_t dac_mux_store(struct device *dev, struct device_attribute *attr, 256 const char *buf, size_t count) 257 { 258 struct aspeed_gfx *priv = dev_get_drvdata(dev); 259 u32 val; 260 int rc; 261 262 rc = kstrtou32(buf, 0, &val); 263 if (rc) 264 return rc; 265 266 if (val > 3) 267 return -EINVAL; 268 269 rc = regmap_update_bits(priv->scu, priv->dac_reg, 0x30000, val << 16); 270 if (rc < 0) 271 return 0; 272 273 return count; 274 } 275 276 static ssize_t dac_mux_show(struct device *dev, struct device_attribute *attr, char *buf) 277 { 278 struct aspeed_gfx *priv = dev_get_drvdata(dev); 279 u32 reg; 280 int rc; 281 282 rc = regmap_read(priv->scu, priv->dac_reg, ®); 283 if (rc) 284 return rc; 285 286 return sprintf(buf, "%u\n", (reg >> 16) & 0x3); 287 } 288 static DEVICE_ATTR_RW(dac_mux); 289 290 static ssize_t 291 vga_pw_show(struct device *dev, struct device_attribute *attr, char *buf) 292 { 293 struct aspeed_gfx *priv = dev_get_drvdata(dev); 294 u32 reg; 295 int rc; 296 297 rc = regmap_read(priv->scu, priv->vga_scratch_reg, ®); 298 if (rc) 299 return rc; 300 301 return sprintf(buf, "%u\n", reg); 302 } 303 static DEVICE_ATTR_RO(vga_pw); 304 305 static struct attribute *aspeed_sysfs_entries[] = { 306 &dev_attr_vga_pw.attr, 307 &dev_attr_dac_mux.attr, 308 NULL, 309 }; 310 311 static struct attribute_group aspeed_sysfs_attr_group = { 312 .attrs = aspeed_sysfs_entries, 313 }; 314 315 static int aspeed_gfx_probe(struct platform_device *pdev) 316 { 317 struct aspeed_gfx *priv; 318 int ret; 319 320 priv = devm_drm_dev_alloc(&pdev->dev, &aspeed_gfx_driver, 321 struct aspeed_gfx, drm); 322 if (IS_ERR(priv)) 323 return PTR_ERR(priv); 324 325 ret = aspeed_gfx_load(&priv->drm); 326 if (ret) 327 return ret; 328 329 platform_set_drvdata(pdev, priv); 330 331 ret = sysfs_create_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 332 if (ret) 333 return ret; 334 335 ret = drm_dev_register(&priv->drm, 0); 336 if (ret) 337 goto err_unload; 338 339 drm_client_setup(&priv->drm, NULL); 340 return 0; 341 342 err_unload: 343 sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 344 aspeed_gfx_unload(&priv->drm); 345 346 return ret; 347 } 348 349 static void aspeed_gfx_remove(struct platform_device *pdev) 350 { 351 struct drm_device *drm = platform_get_drvdata(pdev); 352 353 sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 354 drm_dev_unregister(drm); 355 aspeed_gfx_unload(drm); 356 drm_atomic_helper_shutdown(drm); 357 } 358 359 static void aspeed_gfx_shutdown(struct platform_device *pdev) 360 { 361 drm_atomic_helper_shutdown(platform_get_drvdata(pdev)); 362 } 363 364 static struct platform_driver aspeed_gfx_platform_driver = { 365 .probe = aspeed_gfx_probe, 366 .remove = aspeed_gfx_remove, 367 .shutdown = aspeed_gfx_shutdown, 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"); 379