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 void aspeed_gfx_setup_mode_config(struct drm_device *drm) 67 { 68 drm_mode_config_init(drm); 69 70 drm->mode_config.min_width = 0; 71 drm->mode_config.min_height = 0; 72 drm->mode_config.max_width = 800; 73 drm->mode_config.max_height = 600; 74 drm->mode_config.funcs = &aspeed_gfx_mode_config_funcs; 75 } 76 77 static irqreturn_t aspeed_gfx_irq_handler(int irq, void *data) 78 { 79 struct drm_device *drm = data; 80 struct aspeed_gfx *priv = drm->dev_private; 81 u32 reg; 82 83 reg = readl(priv->base + CRT_CTRL1); 84 85 if (reg & CRT_CTRL_VERTICAL_INTR_STS) { 86 drm_crtc_handle_vblank(&priv->pipe.crtc); 87 writel(reg, priv->base + CRT_CTRL1); 88 return IRQ_HANDLED; 89 } 90 91 return IRQ_NONE; 92 } 93 94 95 96 static int aspeed_gfx_load(struct drm_device *drm) 97 { 98 struct platform_device *pdev = to_platform_device(drm->dev); 99 struct aspeed_gfx *priv; 100 struct resource *res; 101 int ret; 102 103 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); 104 if (!priv) 105 return -ENOMEM; 106 drm->dev_private = priv; 107 108 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 109 priv->base = devm_ioremap_resource(drm->dev, res); 110 if (IS_ERR(priv->base)) 111 return PTR_ERR(priv->base); 112 113 priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu"); 114 if (IS_ERR(priv->scu)) { 115 dev_err(&pdev->dev, "failed to find SCU regmap\n"); 116 return PTR_ERR(priv->scu); 117 } 118 119 ret = of_reserved_mem_device_init(drm->dev); 120 if (ret) { 121 dev_err(&pdev->dev, 122 "failed to initialize reserved mem: %d\n", ret); 123 return ret; 124 } 125 126 ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32)); 127 if (ret) { 128 dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret); 129 return ret; 130 } 131 132 priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); 133 if (IS_ERR(priv->rst)) { 134 dev_err(&pdev->dev, 135 "missing or invalid reset controller device tree entry"); 136 return PTR_ERR(priv->rst); 137 } 138 reset_control_deassert(priv->rst); 139 140 priv->clk = devm_clk_get(drm->dev, NULL); 141 if (IS_ERR(priv->clk)) { 142 dev_err(&pdev->dev, 143 "missing or invalid clk device tree entry"); 144 return PTR_ERR(priv->clk); 145 } 146 clk_prepare_enable(priv->clk); 147 148 /* Sanitize control registers */ 149 writel(0, priv->base + CRT_CTRL1); 150 writel(0, priv->base + CRT_CTRL2); 151 152 aspeed_gfx_setup_mode_config(drm); 153 154 ret = drm_vblank_init(drm, 1); 155 if (ret < 0) { 156 dev_err(drm->dev, "Failed to initialise vblank\n"); 157 return ret; 158 } 159 160 ret = aspeed_gfx_create_output(drm); 161 if (ret < 0) { 162 dev_err(drm->dev, "Failed to create outputs\n"); 163 return ret; 164 } 165 166 ret = aspeed_gfx_create_pipe(drm); 167 if (ret < 0) { 168 dev_err(drm->dev, "Cannot setup simple display pipe\n"); 169 return ret; 170 } 171 172 ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0), 173 aspeed_gfx_irq_handler, 0, "aspeed gfx", drm); 174 if (ret < 0) { 175 dev_err(drm->dev, "Failed to install IRQ handler\n"); 176 return ret; 177 } 178 179 drm_mode_config_reset(drm); 180 181 drm_fbdev_generic_setup(drm, 32); 182 183 return 0; 184 } 185 186 static void aspeed_gfx_unload(struct drm_device *drm) 187 { 188 drm_kms_helper_poll_fini(drm); 189 drm_mode_config_cleanup(drm); 190 191 drm->dev_private = NULL; 192 } 193 194 DEFINE_DRM_GEM_CMA_FOPS(fops); 195 196 static struct drm_driver aspeed_gfx_driver = { 197 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 198 .gem_create_object = drm_cma_gem_create_object_default_funcs, 199 .dumb_create = drm_gem_cma_dumb_create, 200 .prime_handle_to_fd = drm_gem_prime_handle_to_fd, 201 .prime_fd_to_handle = drm_gem_prime_fd_to_handle, 202 .gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table, 203 .gem_prime_mmap = drm_gem_prime_mmap, 204 .fops = &fops, 205 .name = "aspeed-gfx-drm", 206 .desc = "ASPEED GFX DRM", 207 .date = "20180319", 208 .major = 1, 209 .minor = 0, 210 }; 211 212 static const struct of_device_id aspeed_gfx_match[] = { 213 { .compatible = "aspeed,ast2500-gfx" }, 214 { } 215 }; 216 217 static int aspeed_gfx_probe(struct platform_device *pdev) 218 { 219 struct drm_device *drm; 220 int ret; 221 222 drm = drm_dev_alloc(&aspeed_gfx_driver, &pdev->dev); 223 if (IS_ERR(drm)) 224 return PTR_ERR(drm); 225 226 ret = aspeed_gfx_load(drm); 227 if (ret) 228 goto err_free; 229 230 ret = drm_dev_register(drm, 0); 231 if (ret) 232 goto err_unload; 233 234 return 0; 235 236 err_unload: 237 aspeed_gfx_unload(drm); 238 err_free: 239 drm_dev_put(drm); 240 241 return ret; 242 } 243 244 static int aspeed_gfx_remove(struct platform_device *pdev) 245 { 246 struct drm_device *drm = platform_get_drvdata(pdev); 247 248 drm_dev_unregister(drm); 249 aspeed_gfx_unload(drm); 250 drm_dev_put(drm); 251 252 return 0; 253 } 254 255 static struct platform_driver aspeed_gfx_platform_driver = { 256 .probe = aspeed_gfx_probe, 257 .remove = aspeed_gfx_remove, 258 .driver = { 259 .name = "aspeed_gfx", 260 .of_match_table = aspeed_gfx_match, 261 }, 262 }; 263 264 module_platform_driver(aspeed_gfx_platform_driver); 265 266 MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>"); 267 MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver"); 268 MODULE_LICENSE("GPL"); 269