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_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 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 .vga_scratch_reg = 0x50, 71 .throd_val = CRT_THROD_LOW(0x1e) | CRT_THROD_HIGH(0x12), 72 .scan_line_max = 64, 73 }; 74 75 static const struct aspeed_gfx_config ast2500_config = { 76 .dac_reg = 0x2c, 77 .vga_scratch_reg = 0x50, 78 .throd_val = CRT_THROD_LOW(0x24) | CRT_THROD_HIGH(0x3c), 79 .scan_line_max = 128, 80 }; 81 82 static const struct of_device_id aspeed_gfx_match[] = { 83 { .compatible = "aspeed,ast2400-gfx", .data = &ast2400_config }, 84 { .compatible = "aspeed,ast2500-gfx", .data = &ast2500_config }, 85 { }, 86 }; 87 MODULE_DEVICE_TABLE(of, aspeed_gfx_match); 88 89 static const struct drm_mode_config_funcs aspeed_gfx_mode_config_funcs = { 90 .fb_create = drm_gem_fb_create, 91 .atomic_check = drm_atomic_helper_check, 92 .atomic_commit = drm_atomic_helper_commit, 93 }; 94 95 static int aspeed_gfx_setup_mode_config(struct drm_device *drm) 96 { 97 int ret; 98 99 ret = drmm_mode_config_init(drm); 100 if (ret) 101 return ret; 102 103 drm->mode_config.min_width = 0; 104 drm->mode_config.min_height = 0; 105 drm->mode_config.max_width = 800; 106 drm->mode_config.max_height = 600; 107 drm->mode_config.funcs = &aspeed_gfx_mode_config_funcs; 108 109 return ret; 110 } 111 112 static irqreturn_t aspeed_gfx_irq_handler(int irq, void *data) 113 { 114 struct drm_device *drm = data; 115 struct aspeed_gfx *priv = to_aspeed_gfx(drm); 116 u32 reg; 117 118 reg = readl(priv->base + CRT_CTRL1); 119 120 if (reg & CRT_CTRL_VERTICAL_INTR_STS) { 121 drm_crtc_handle_vblank(&priv->pipe.crtc); 122 writel(reg, priv->base + CRT_CTRL1); 123 return IRQ_HANDLED; 124 } 125 126 return IRQ_NONE; 127 } 128 129 static int aspeed_gfx_load(struct drm_device *drm) 130 { 131 struct platform_device *pdev = to_platform_device(drm->dev); 132 struct aspeed_gfx *priv = to_aspeed_gfx(drm); 133 struct device_node *np = pdev->dev.of_node; 134 const struct aspeed_gfx_config *config; 135 const struct of_device_id *match; 136 struct resource *res; 137 int ret; 138 139 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 140 priv->base = devm_ioremap_resource(drm->dev, res); 141 if (IS_ERR(priv->base)) 142 return PTR_ERR(priv->base); 143 144 match = of_match_device(aspeed_gfx_match, &pdev->dev); 145 if (!match) 146 return -EINVAL; 147 config = match->data; 148 149 priv->dac_reg = config->dac_reg; 150 priv->vga_scratch_reg = config->vga_scratch_reg; 151 priv->throd_val = config->throd_val; 152 priv->scan_line_max = config->scan_line_max; 153 154 priv->scu = syscon_regmap_lookup_by_phandle(np, "syscon"); 155 if (IS_ERR(priv->scu)) { 156 priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu"); 157 if (IS_ERR(priv->scu)) { 158 dev_err(&pdev->dev, "failed to find SCU regmap\n"); 159 return PTR_ERR(priv->scu); 160 } 161 } 162 163 ret = of_reserved_mem_device_init(drm->dev); 164 if (ret) { 165 dev_err(&pdev->dev, 166 "failed to initialize reserved mem: %d\n", ret); 167 return ret; 168 } 169 170 ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32)); 171 if (ret) { 172 dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret); 173 return ret; 174 } 175 176 priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); 177 if (IS_ERR(priv->rst)) { 178 dev_err(&pdev->dev, 179 "missing or invalid reset controller device tree entry"); 180 return PTR_ERR(priv->rst); 181 } 182 reset_control_deassert(priv->rst); 183 184 priv->clk = devm_clk_get(drm->dev, NULL); 185 if (IS_ERR(priv->clk)) { 186 dev_err(&pdev->dev, 187 "missing or invalid clk device tree entry"); 188 return PTR_ERR(priv->clk); 189 } 190 clk_prepare_enable(priv->clk); 191 192 /* Sanitize control registers */ 193 writel(0, priv->base + CRT_CTRL1); 194 writel(0, priv->base + CRT_CTRL2); 195 196 ret = aspeed_gfx_setup_mode_config(drm); 197 if (ret < 0) 198 return ret; 199 200 ret = drm_vblank_init(drm, 1); 201 if (ret < 0) { 202 dev_err(drm->dev, "Failed to initialise vblank\n"); 203 return ret; 204 } 205 206 ret = aspeed_gfx_create_output(drm); 207 if (ret < 0) { 208 dev_err(drm->dev, "Failed to create outputs\n"); 209 return ret; 210 } 211 212 ret = aspeed_gfx_create_pipe(drm); 213 if (ret < 0) { 214 dev_err(drm->dev, "Cannot setup simple display pipe\n"); 215 return ret; 216 } 217 218 ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0), 219 aspeed_gfx_irq_handler, 0, "aspeed gfx", drm); 220 if (ret < 0) { 221 dev_err(drm->dev, "Failed to install IRQ handler\n"); 222 return ret; 223 } 224 225 drm_mode_config_reset(drm); 226 227 return 0; 228 } 229 230 static void aspeed_gfx_unload(struct drm_device *drm) 231 { 232 drm_kms_helper_poll_fini(drm); 233 } 234 235 DEFINE_DRM_GEM_CMA_FOPS(fops); 236 237 static const struct drm_driver aspeed_gfx_driver = { 238 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 239 DRM_GEM_CMA_DRIVER_OPS, 240 .fops = &fops, 241 .name = "aspeed-gfx-drm", 242 .desc = "ASPEED GFX DRM", 243 .date = "20180319", 244 .major = 1, 245 .minor = 0, 246 }; 247 248 static ssize_t dac_mux_store(struct device *dev, struct device_attribute *attr, 249 const char *buf, size_t count) 250 { 251 struct aspeed_gfx *priv = dev_get_drvdata(dev); 252 u32 val; 253 int rc; 254 255 rc = kstrtou32(buf, 0, &val); 256 if (rc) 257 return rc; 258 259 if (val > 3) 260 return -EINVAL; 261 262 rc = regmap_update_bits(priv->scu, priv->dac_reg, 0x30000, val << 16); 263 if (rc < 0) 264 return 0; 265 266 return count; 267 } 268 269 static ssize_t dac_mux_show(struct device *dev, struct device_attribute *attr, char *buf) 270 { 271 struct aspeed_gfx *priv = dev_get_drvdata(dev); 272 u32 reg; 273 int rc; 274 275 rc = regmap_read(priv->scu, priv->dac_reg, ®); 276 if (rc) 277 return rc; 278 279 return sprintf(buf, "%u\n", (reg >> 16) & 0x3); 280 } 281 static DEVICE_ATTR_RW(dac_mux); 282 283 static ssize_t 284 vga_pw_show(struct device *dev, struct device_attribute *attr, char *buf) 285 { 286 struct aspeed_gfx *priv = dev_get_drvdata(dev); 287 u32 reg; 288 int rc; 289 290 rc = regmap_read(priv->scu, priv->vga_scratch_reg, ®); 291 if (rc) 292 return rc; 293 294 return sprintf(buf, "%u\n", reg & 1); 295 } 296 static DEVICE_ATTR_RO(vga_pw); 297 298 static struct attribute *aspeed_sysfs_entries[] = { 299 &dev_attr_vga_pw.attr, 300 &dev_attr_dac_mux.attr, 301 NULL, 302 }; 303 304 static struct attribute_group aspeed_sysfs_attr_group = { 305 .attrs = aspeed_sysfs_entries, 306 }; 307 308 static int aspeed_gfx_probe(struct platform_device *pdev) 309 { 310 struct aspeed_gfx *priv; 311 int ret; 312 313 priv = devm_drm_dev_alloc(&pdev->dev, &aspeed_gfx_driver, 314 struct aspeed_gfx, drm); 315 if (IS_ERR(priv)) 316 return PTR_ERR(priv); 317 318 ret = aspeed_gfx_load(&priv->drm); 319 if (ret) 320 return ret; 321 322 platform_set_drvdata(pdev, priv); 323 324 ret = sysfs_create_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 325 if (ret) 326 return ret; 327 328 ret = drm_dev_register(&priv->drm, 0); 329 if (ret) 330 goto err_unload; 331 332 drm_fbdev_generic_setup(&priv->drm, 32); 333 return 0; 334 335 err_unload: 336 sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 337 aspeed_gfx_unload(&priv->drm); 338 339 return ret; 340 } 341 342 static int aspeed_gfx_remove(struct platform_device *pdev) 343 { 344 struct drm_device *drm = platform_get_drvdata(pdev); 345 346 sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 347 drm_dev_unregister(drm); 348 aspeed_gfx_unload(drm); 349 350 return 0; 351 } 352 353 static struct platform_driver aspeed_gfx_platform_driver = { 354 .probe = aspeed_gfx_probe, 355 .remove = aspeed_gfx_remove, 356 .driver = { 357 .name = "aspeed_gfx", 358 .of_match_table = aspeed_gfx_match, 359 }, 360 }; 361 362 module_platform_driver(aspeed_gfx_platform_driver); 363 364 MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>"); 365 MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver"); 366 MODULE_LICENSE("GPL"); 367