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_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 struct resource *res; 147 int ret; 148 149 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 150 priv->base = devm_ioremap_resource(drm->dev, res); 151 if (IS_ERR(priv->base)) 152 return PTR_ERR(priv->base); 153 154 config = device_get_match_data(&pdev->dev); 155 if (!config) 156 return -EINVAL; 157 158 priv->dac_reg = config->dac_reg; 159 priv->int_clr_reg = config->int_clear_reg; 160 priv->vga_scratch_reg = config->vga_scratch_reg; 161 priv->throd_val = config->throd_val; 162 priv->scan_line_max = config->scan_line_max; 163 164 priv->scu = syscon_regmap_lookup_by_phandle(np, "syscon"); 165 if (IS_ERR(priv->scu)) { 166 priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu"); 167 if (IS_ERR(priv->scu)) { 168 dev_err(&pdev->dev, "failed to find SCU regmap\n"); 169 return PTR_ERR(priv->scu); 170 } 171 } 172 173 ret = of_reserved_mem_device_init(drm->dev); 174 if (ret) { 175 dev_err(&pdev->dev, 176 "failed to initialize reserved mem: %d\n", ret); 177 return ret; 178 } 179 180 ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32)); 181 if (ret) { 182 dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret); 183 return ret; 184 } 185 186 priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); 187 if (IS_ERR(priv->rst)) { 188 dev_err(&pdev->dev, 189 "missing or invalid reset controller device tree entry"); 190 return PTR_ERR(priv->rst); 191 } 192 reset_control_deassert(priv->rst); 193 194 priv->clk = devm_clk_get(drm->dev, NULL); 195 if (IS_ERR(priv->clk)) { 196 dev_err(&pdev->dev, 197 "missing or invalid clk device tree entry"); 198 return PTR_ERR(priv->clk); 199 } 200 clk_prepare_enable(priv->clk); 201 202 /* Sanitize control registers */ 203 writel(0, priv->base + CRT_CTRL1); 204 writel(0, priv->base + CRT_CTRL2); 205 206 ret = aspeed_gfx_setup_mode_config(drm); 207 if (ret < 0) 208 return ret; 209 210 ret = drm_vblank_init(drm, 1); 211 if (ret < 0) { 212 dev_err(drm->dev, "Failed to initialise vblank\n"); 213 return ret; 214 } 215 216 ret = aspeed_gfx_create_output(drm); 217 if (ret < 0) { 218 dev_err(drm->dev, "Failed to create outputs\n"); 219 return ret; 220 } 221 222 ret = aspeed_gfx_create_pipe(drm); 223 if (ret < 0) { 224 dev_err(drm->dev, "Cannot setup simple display pipe\n"); 225 return ret; 226 } 227 228 ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0), 229 aspeed_gfx_irq_handler, 0, "aspeed gfx", drm); 230 if (ret < 0) { 231 dev_err(drm->dev, "Failed to install IRQ handler\n"); 232 return ret; 233 } 234 235 drm_mode_config_reset(drm); 236 237 return 0; 238 } 239 240 static void aspeed_gfx_unload(struct drm_device *drm) 241 { 242 drm_kms_helper_poll_fini(drm); 243 } 244 245 DEFINE_DRM_GEM_DMA_FOPS(fops); 246 247 static const struct drm_driver aspeed_gfx_driver = { 248 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 249 DRM_GEM_DMA_DRIVER_OPS, 250 .fops = &fops, 251 .name = "aspeed-gfx-drm", 252 .desc = "ASPEED GFX DRM", 253 .date = "20180319", 254 .major = 1, 255 .minor = 0, 256 }; 257 258 static ssize_t dac_mux_store(struct device *dev, struct device_attribute *attr, 259 const char *buf, size_t count) 260 { 261 struct aspeed_gfx *priv = dev_get_drvdata(dev); 262 u32 val; 263 int rc; 264 265 rc = kstrtou32(buf, 0, &val); 266 if (rc) 267 return rc; 268 269 if (val > 3) 270 return -EINVAL; 271 272 rc = regmap_update_bits(priv->scu, priv->dac_reg, 0x30000, val << 16); 273 if (rc < 0) 274 return 0; 275 276 return count; 277 } 278 279 static ssize_t dac_mux_show(struct device *dev, struct device_attribute *attr, char *buf) 280 { 281 struct aspeed_gfx *priv = dev_get_drvdata(dev); 282 u32 reg; 283 int rc; 284 285 rc = regmap_read(priv->scu, priv->dac_reg, ®); 286 if (rc) 287 return rc; 288 289 return sprintf(buf, "%u\n", (reg >> 16) & 0x3); 290 } 291 static DEVICE_ATTR_RW(dac_mux); 292 293 static ssize_t 294 vga_pw_show(struct device *dev, struct device_attribute *attr, char *buf) 295 { 296 struct aspeed_gfx *priv = dev_get_drvdata(dev); 297 u32 reg; 298 int rc; 299 300 rc = regmap_read(priv->scu, priv->vga_scratch_reg, ®); 301 if (rc) 302 return rc; 303 304 return sprintf(buf, "%u\n", reg); 305 } 306 static DEVICE_ATTR_RO(vga_pw); 307 308 static struct attribute *aspeed_sysfs_entries[] = { 309 &dev_attr_vga_pw.attr, 310 &dev_attr_dac_mux.attr, 311 NULL, 312 }; 313 314 static struct attribute_group aspeed_sysfs_attr_group = { 315 .attrs = aspeed_sysfs_entries, 316 }; 317 318 static int aspeed_gfx_probe(struct platform_device *pdev) 319 { 320 struct aspeed_gfx *priv; 321 int ret; 322 323 priv = devm_drm_dev_alloc(&pdev->dev, &aspeed_gfx_driver, 324 struct aspeed_gfx, drm); 325 if (IS_ERR(priv)) 326 return PTR_ERR(priv); 327 328 ret = aspeed_gfx_load(&priv->drm); 329 if (ret) 330 return ret; 331 332 platform_set_drvdata(pdev, priv); 333 334 ret = sysfs_create_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 335 if (ret) 336 return ret; 337 338 ret = drm_dev_register(&priv->drm, 0); 339 if (ret) 340 goto err_unload; 341 342 drm_fbdev_dma_setup(&priv->drm, 32); 343 return 0; 344 345 err_unload: 346 sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 347 aspeed_gfx_unload(&priv->drm); 348 349 return ret; 350 } 351 352 static void aspeed_gfx_remove(struct platform_device *pdev) 353 { 354 struct drm_device *drm = platform_get_drvdata(pdev); 355 356 sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 357 drm_dev_unregister(drm); 358 aspeed_gfx_unload(drm); 359 drm_atomic_helper_shutdown(drm); 360 } 361 362 static void aspeed_gfx_shutdown(struct platform_device *pdev) 363 { 364 drm_atomic_helper_shutdown(platform_get_drvdata(pdev)); 365 } 366 367 static struct platform_driver aspeed_gfx_platform_driver = { 368 .probe = aspeed_gfx_probe, 369 .remove_new = aspeed_gfx_remove, 370 .shutdown = aspeed_gfx_shutdown, 371 .driver = { 372 .name = "aspeed_gfx", 373 .of_match_table = aspeed_gfx_match, 374 }, 375 }; 376 377 drm_module_platform_driver(aspeed_gfx_platform_driver); 378 379 MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>"); 380 MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver"); 381 MODULE_LICENSE("GPL"); 382