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_reserved_mem.h> 11 #include <linux/platform_device.h> 12 #include <linux/regmap.h> 13 #include <linux/reset.h> 14 15 #include <drm/drm_atomic_helper.h> 16 #include <drm/drm_crtc_helper.h> 17 #include <drm/drm_device.h> 18 #include <drm/drm_fb_cma_helper.h> 19 #include <drm/drm_fb_helper.h> 20 #include <drm/drm_gem_cma_helper.h> 21 #include <drm/drm_gem_framebuffer_helper.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 static const struct drm_mode_config_funcs aspeed_gfx_mode_config_funcs = { 61 .fb_create = drm_gem_fb_create, 62 .atomic_check = drm_atomic_helper_check, 63 .atomic_commit = drm_atomic_helper_commit, 64 }; 65 66 static int aspeed_gfx_setup_mode_config(struct drm_device *drm) 67 { 68 int ret; 69 70 ret = drmm_mode_config_init(drm); 71 if (ret) 72 return ret; 73 74 drm->mode_config.min_width = 0; 75 drm->mode_config.min_height = 0; 76 drm->mode_config.max_width = 800; 77 drm->mode_config.max_height = 600; 78 drm->mode_config.funcs = &aspeed_gfx_mode_config_funcs; 79 80 return ret; 81 } 82 83 static irqreturn_t aspeed_gfx_irq_handler(int irq, void *data) 84 { 85 struct drm_device *drm = data; 86 struct aspeed_gfx *priv = to_aspeed_gfx(drm); 87 u32 reg; 88 89 reg = readl(priv->base + CRT_CTRL1); 90 91 if (reg & CRT_CTRL_VERTICAL_INTR_STS) { 92 drm_crtc_handle_vblank(&priv->pipe.crtc); 93 writel(reg, priv->base + CRT_CTRL1); 94 return IRQ_HANDLED; 95 } 96 97 return IRQ_NONE; 98 } 99 100 101 102 static int aspeed_gfx_load(struct drm_device *drm) 103 { 104 struct platform_device *pdev = to_platform_device(drm->dev); 105 struct aspeed_gfx *priv = to_aspeed_gfx(drm); 106 struct resource *res; 107 int ret; 108 109 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 110 priv->base = devm_ioremap_resource(drm->dev, res); 111 if (IS_ERR(priv->base)) 112 return PTR_ERR(priv->base); 113 114 priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu"); 115 if (IS_ERR(priv->scu)) { 116 dev_err(&pdev->dev, "failed to find SCU regmap\n"); 117 return PTR_ERR(priv->scu); 118 } 119 120 ret = of_reserved_mem_device_init(drm->dev); 121 if (ret) { 122 dev_err(&pdev->dev, 123 "failed to initialize reserved mem: %d\n", ret); 124 return ret; 125 } 126 127 ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32)); 128 if (ret) { 129 dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret); 130 return ret; 131 } 132 133 priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); 134 if (IS_ERR(priv->rst)) { 135 dev_err(&pdev->dev, 136 "missing or invalid reset controller device tree entry"); 137 return PTR_ERR(priv->rst); 138 } 139 reset_control_deassert(priv->rst); 140 141 priv->clk = devm_clk_get(drm->dev, NULL); 142 if (IS_ERR(priv->clk)) { 143 dev_err(&pdev->dev, 144 "missing or invalid clk device tree entry"); 145 return PTR_ERR(priv->clk); 146 } 147 clk_prepare_enable(priv->clk); 148 149 /* Sanitize control registers */ 150 writel(0, priv->base + CRT_CTRL1); 151 writel(0, priv->base + CRT_CTRL2); 152 153 ret = aspeed_gfx_setup_mode_config(drm); 154 if (ret < 0) 155 return ret; 156 157 ret = drm_vblank_init(drm, 1); 158 if (ret < 0) { 159 dev_err(drm->dev, "Failed to initialise vblank\n"); 160 return ret; 161 } 162 163 ret = aspeed_gfx_create_output(drm); 164 if (ret < 0) { 165 dev_err(drm->dev, "Failed to create outputs\n"); 166 return ret; 167 } 168 169 ret = aspeed_gfx_create_pipe(drm); 170 if (ret < 0) { 171 dev_err(drm->dev, "Cannot setup simple display pipe\n"); 172 return ret; 173 } 174 175 ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0), 176 aspeed_gfx_irq_handler, 0, "aspeed gfx", drm); 177 if (ret < 0) { 178 dev_err(drm->dev, "Failed to install IRQ handler\n"); 179 return ret; 180 } 181 182 drm_mode_config_reset(drm); 183 184 return 0; 185 } 186 187 static void aspeed_gfx_unload(struct drm_device *drm) 188 { 189 drm_kms_helper_poll_fini(drm); 190 } 191 192 DEFINE_DRM_GEM_CMA_FOPS(fops); 193 194 static const struct drm_driver aspeed_gfx_driver = { 195 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 196 DRM_GEM_CMA_DRIVER_OPS, 197 .fops = &fops, 198 .name = "aspeed-gfx-drm", 199 .desc = "ASPEED GFX DRM", 200 .date = "20180319", 201 .major = 1, 202 .minor = 0, 203 }; 204 205 static const struct of_device_id aspeed_gfx_match[] = { 206 { .compatible = "aspeed,ast2500-gfx" }, 207 { } 208 }; 209 210 #define ASPEED_SCU_VGA0 0x50 211 #define ASPEED_SCU_MISC_CTRL 0x2c 212 213 static ssize_t dac_mux_store(struct device *dev, struct device_attribute *attr, 214 const char *buf, size_t count) 215 { 216 struct aspeed_gfx *priv = dev_get_drvdata(dev); 217 u32 val; 218 int rc; 219 220 rc = kstrtou32(buf, 0, &val); 221 if (rc) 222 return rc; 223 224 if (val > 3) 225 return -EINVAL; 226 227 rc = regmap_update_bits(priv->scu, ASPEED_SCU_MISC_CTRL, 0x30000, val << 16); 228 if (rc < 0) 229 return 0; 230 231 return count; 232 } 233 234 static ssize_t dac_mux_show(struct device *dev, struct device_attribute *attr, char *buf) 235 { 236 struct aspeed_gfx *priv = dev_get_drvdata(dev); 237 u32 reg; 238 int rc; 239 240 rc = regmap_read(priv->scu, ASPEED_SCU_MISC_CTRL, ®); 241 if (rc) 242 return rc; 243 244 return sprintf(buf, "%u\n", (reg >> 16) & 0x3); 245 } 246 static DEVICE_ATTR_RW(dac_mux); 247 248 static ssize_t 249 vga_pw_show(struct device *dev, struct device_attribute *attr, char *buf) 250 { 251 struct aspeed_gfx *priv = dev_get_drvdata(dev); 252 u32 reg; 253 int rc; 254 255 rc = regmap_read(priv->scu, ASPEED_SCU_VGA0, ®); 256 if (rc) 257 return rc; 258 259 return sprintf(buf, "%u\n", reg & 1); 260 } 261 static DEVICE_ATTR_RO(vga_pw); 262 263 static struct attribute *aspeed_sysfs_entries[] = { 264 &dev_attr_vga_pw.attr, 265 &dev_attr_dac_mux.attr, 266 NULL, 267 }; 268 269 static struct attribute_group aspeed_sysfs_attr_group = { 270 .attrs = aspeed_sysfs_entries, 271 }; 272 273 static int aspeed_gfx_probe(struct platform_device *pdev) 274 { 275 struct aspeed_gfx *priv; 276 int ret; 277 278 priv = devm_drm_dev_alloc(&pdev->dev, &aspeed_gfx_driver, 279 struct aspeed_gfx, drm); 280 if (IS_ERR(priv)) 281 return PTR_ERR(priv); 282 283 ret = aspeed_gfx_load(&priv->drm); 284 if (ret) 285 return ret; 286 287 dev_set_drvdata(&pdev->dev, priv); 288 289 ret = sysfs_create_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 290 if (ret) 291 return ret; 292 293 ret = drm_dev_register(&priv->drm, 0); 294 if (ret) 295 goto err_unload; 296 297 drm_fbdev_generic_setup(&priv->drm, 32); 298 return 0; 299 300 err_unload: 301 sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 302 aspeed_gfx_unload(&priv->drm); 303 304 return ret; 305 } 306 307 static int aspeed_gfx_remove(struct platform_device *pdev) 308 { 309 struct drm_device *drm = platform_get_drvdata(pdev); 310 311 sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group); 312 drm_dev_unregister(drm); 313 aspeed_gfx_unload(drm); 314 315 return 0; 316 } 317 318 static struct platform_driver aspeed_gfx_platform_driver = { 319 .probe = aspeed_gfx_probe, 320 .remove = aspeed_gfx_remove, 321 .driver = { 322 .name = "aspeed_gfx", 323 .of_match_table = aspeed_gfx_match, 324 }, 325 }; 326 327 module_platform_driver(aspeed_gfx_platform_driver); 328 329 MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>"); 330 MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver"); 331 MODULE_LICENSE("GPL"); 332