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_module.h> 24 #include <drm/drm_probe_helper.h> 25 #include <drm/drm_simple_kms_helper.h> 26 #include <drm/drm_vblank.h> 27 #include <drm/drm_drv.h> 28 29 #include "aspeed_gfx.h" 30 31 /** 32 * DOC: ASPEED GFX Driver 33 * 34 * This driver is for the ASPEED BMC SoC's 'GFX' display hardware, also called 35 * the 'SOC Display Controller' in the datasheet. This driver runs on the ARM 36 * based BMC systems, unlike the ast driver which runs on a host CPU and is for 37 * a PCIe graphics device. 38 * 39 * The AST2500 supports a total of 3 output paths: 40 * 41 * 1. VGA output, the output target can choose either or both to the DAC 42 * or DVO interface. 43 * 44 * 2. Graphics CRT output, the output target can choose either or both to 45 * the DAC or DVO interface. 46 * 47 * 3. Video input from DVO, the video input can be used for video engine 48 * capture or DAC display output. 49 * 50 * Output options are selected in SCU2C. 51 * 52 * The "VGA mode" device is the PCI attached controller. The "Graphics CRT" 53 * is the ARM's internal display controller. 54 * 55 * The driver only supports a simple configuration consisting of a 40MHz 56 * pixel clock, fixed by hardware limitations, and the VGA output path. 57 * 58 * The driver was written with the 'AST2500 Software Programming Guide' v17, 59 * which is available under NDA from ASPEED. 60 */ 61 62 struct aspeed_gfx_config { 63 u32 dac_reg; /* DAC register in SCU */ 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 .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 .vga_scratch_reg = 0x50, 79 .throd_val = CRT_THROD_LOW(0x24) | CRT_THROD_HIGH(0x3c), 80 .scan_line_max = 128, 81 }; 82 83 static const struct of_device_id aspeed_gfx_match[] = { 84 { .compatible = "aspeed,ast2400-gfx", .data = &ast2400_config }, 85 { .compatible = "aspeed,ast2500-gfx", .data = &ast2500_config }, 86 { }, 87 }; 88 MODULE_DEVICE_TABLE(of, aspeed_gfx_match); 89 90 static const struct drm_mode_config_funcs aspeed_gfx_mode_config_funcs = { 91 .fb_create = drm_gem_fb_create, 92 .atomic_check = drm_atomic_helper_check, 93 .atomic_commit = drm_atomic_helper_commit, 94 }; 95 96 static int aspeed_gfx_setup_mode_config(struct drm_device *drm) 97 { 98 int ret; 99 100 ret = drmm_mode_config_init(drm); 101 if (ret) 102 return ret; 103 104 drm->mode_config.min_width = 0; 105 drm->mode_config.min_height = 0; 106 drm->mode_config.max_width = 800; 107 drm->mode_config.max_height = 600; 108 drm->mode_config.funcs = &aspeed_gfx_mode_config_funcs; 109 110 return ret; 111 } 112 113 static irqreturn_t aspeed_gfx_irq_handler(int irq, void *data) 114 { 115 struct drm_device *drm = data; 116 struct aspeed_gfx *priv = to_aspeed_gfx(drm); 117 u32 reg; 118 119 reg = readl(priv->base + CRT_CTRL1); 120 121 if (reg & CRT_CTRL_VERTICAL_INTR_STS) { 122 drm_crtc_handle_vblank(&priv->pipe.crtc); 123 writel(reg, priv->base + CRT_CTRL1); 124 return IRQ_HANDLED; 125 } 126 127 return IRQ_NONE; 128 } 129 130 static int aspeed_gfx_load(struct drm_device *drm) 131 { 132 struct platform_device *pdev = to_platform_device(drm->dev); 133 struct aspeed_gfx *priv = to_aspeed_gfx(drm); 134 struct device_node *np = pdev->dev.of_node; 135 const struct aspeed_gfx_config *config; 136 const struct of_device_id *match; 137 struct resource *res; 138 int ret; 139 140 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 141 priv->base = devm_ioremap_resource(drm->dev, res); 142 if (IS_ERR(priv->base)) 143 return PTR_ERR(priv->base); 144 145 match = of_match_device(aspeed_gfx_match, &pdev->dev); 146 if (!match) 147 return -EINVAL; 148 config = match->data; 149 150 priv->dac_reg = config->dac_reg; 151 priv->vga_scratch_reg = config->vga_scratch_reg; 152 priv->throd_val = config->throd_val; 153 priv->scan_line_max = config->scan_line_max; 154 155 priv->scu = syscon_regmap_lookup_by_phandle(np, "syscon"); 156 if (IS_ERR(priv->scu)) { 157 priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu"); 158 if (IS_ERR(priv->scu)) { 159 dev_err(&pdev->dev, "failed to find SCU regmap\n"); 160 return PTR_ERR(priv->scu); 161 } 162 } 163 164 ret = of_reserved_mem_device_init(drm->dev); 165 if (ret) { 166 dev_err(&pdev->dev, 167 "failed to initialize reserved mem: %d\n", ret); 168 return ret; 169 } 170 171 ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32)); 172 if (ret) { 173 dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret); 174 return ret; 175 } 176 177 priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); 178 if (IS_ERR(priv->rst)) { 179 dev_err(&pdev->dev, 180 "missing or invalid reset controller device tree entry"); 181 return PTR_ERR(priv->rst); 182 } 183 reset_control_deassert(priv->rst); 184 185 priv->clk = devm_clk_get(drm->dev, NULL); 186 if (IS_ERR(priv->clk)) { 187 dev_err(&pdev->dev, 188 "missing or invalid clk device tree entry"); 189 return PTR_ERR(priv->clk); 190 } 191 clk_prepare_enable(priv->clk); 192 193 /* Sanitize control registers */ 194 writel(0, priv->base + CRT_CTRL1); 195 writel(0, priv->base + CRT_CTRL2); 196 197 ret = aspeed_gfx_setup_mode_config(drm); 198 if (ret < 0) 199 return ret; 200 201 ret = drm_vblank_init(drm, 1); 202 if (ret < 0) { 203 dev_err(drm->dev, "Failed to initialise vblank\n"); 204 return ret; 205 } 206 207 ret = aspeed_gfx_create_output(drm); 208 if (ret < 0) { 209 dev_err(drm->dev, "Failed to create outputs\n"); 210 return ret; 211 } 212 213 ret = aspeed_gfx_create_pipe(drm); 214 if (ret < 0) { 215 dev_err(drm->dev, "Cannot setup simple display pipe\n"); 216 return ret; 217 } 218 219 ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0), 220 aspeed_gfx_irq_handler, 0, "aspeed gfx", drm); 221 if (ret < 0) { 222 dev_err(drm->dev, "Failed to install IRQ handler\n"); 223 return ret; 224 } 225 226 drm_mode_config_reset(drm); 227 228 return 0; 229 } 230 231 static void aspeed_gfx_unload(struct drm_device *drm) 232 { 233 drm_kms_helper_poll_fini(drm); 234 } 235 236 DEFINE_DRM_GEM_CMA_FOPS(fops); 237 238 static const struct drm_driver aspeed_gfx_driver = { 239 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 240 DRM_GEM_CMA_DRIVER_OPS, 241 .fops = &fops, 242 .name = "aspeed-gfx-drm", 243 .desc = "ASPEED GFX DRM", 244 .date = "20180319", 245 .major = 1, 246 .minor = 0, 247 }; 248 249 static ssize_t dac_mux_store(struct device *dev, struct device_attribute *attr, 250 const char *buf, size_t count) 251 { 252 struct aspeed_gfx *priv = dev_get_drvdata(dev); 253 u32 val; 254 int rc; 255 256 rc = kstrtou32(buf, 0, &val); 257 if (rc) 258 return rc; 259 260 if (val > 3) 261 return -EINVAL; 262 263 rc = regmap_update_bits(priv->scu, priv->dac_reg, 0x30000, val << 16); 264 if (rc < 0) 265 return 0; 266 267 return count; 268 } 269 270 static ssize_t dac_mux_show(struct device *dev, struct device_attribute *attr, char *buf) 271 { 272 struct aspeed_gfx *priv = dev_get_drvdata(dev); 273 u32 reg; 274 int rc; 275 276 rc = regmap_read(priv->scu, priv->dac_reg, ®); 277 if (rc) 278 return rc; 279 280 return sprintf(buf, "%u\n", (reg >> 16) & 0x3); 281 } 282 static DEVICE_ATTR_RW(dac_mux); 283 284 static ssize_t 285 vga_pw_show(struct device *dev, struct device_attribute *attr, char *buf) 286 { 287 struct aspeed_gfx *priv = dev_get_drvdata(dev); 288 u32 reg; 289 int rc; 290 291 rc = regmap_read(priv->scu, priv->vga_scratch_reg, ®); 292 if (rc) 293 return rc; 294 295 return sprintf(buf, "%u\n", reg); 296 } 297 static DEVICE_ATTR_RO(vga_pw); 298 299 static struct attribute *aspeed_sysfs_entries[] = { 300 &dev_attr_vga_pw.attr, 301 &dev_attr_dac_mux.attr, 302 NULL, 303 }; 304 305 static struct attribute_group aspeed_sysfs_attr_group = { 306 .attrs = aspeed_sysfs_entries, 307 }; 308 309 static int aspeed_gfx_probe(struct platform_device *pdev) 310 { 311 struct aspeed_gfx *priv; 312 int ret; 313 314 priv = devm_drm_dev_alloc(&pdev->dev, &aspeed_gfx_driver, 315 struct aspeed_gfx, drm); 316 if (IS_ERR(priv)) 317 return PTR_ERR(priv); 318 319 ret = aspeed_gfx_load(&priv->drm); 320 if (ret) 321 return ret; 322 323 platform_set_drvdata(pdev, priv); 324 325 ret = sysfs_create_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 326 if (ret) 327 return ret; 328 329 ret = drm_dev_register(&priv->drm, 0); 330 if (ret) 331 goto err_unload; 332 333 drm_fbdev_generic_setup(&priv->drm, 32); 334 return 0; 335 336 err_unload: 337 sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 338 aspeed_gfx_unload(&priv->drm); 339 340 return ret; 341 } 342 343 static int aspeed_gfx_remove(struct platform_device *pdev) 344 { 345 struct drm_device *drm = platform_get_drvdata(pdev); 346 347 sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 348 drm_dev_unregister(drm); 349 aspeed_gfx_unload(drm); 350 351 return 0; 352 } 353 354 static struct platform_driver aspeed_gfx_platform_driver = { 355 .probe = aspeed_gfx_probe, 356 .remove = aspeed_gfx_remove, 357 .driver = { 358 .name = "aspeed_gfx", 359 .of_match_table = aspeed_gfx_match, 360 }, 361 }; 362 363 drm_module_platform_driver(aspeed_gfx_platform_driver); 364 365 MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>"); 366 MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver"); 367 MODULE_LICENSE("GPL"); 368