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 = to_aspeed_gfx(drm); 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 = to_aspeed_gfx(drm); 100 struct resource *res; 101 int ret; 102 103 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 104 priv->base = devm_ioremap_resource(drm->dev, res); 105 if (IS_ERR(priv->base)) 106 return PTR_ERR(priv->base); 107 108 priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu"); 109 if (IS_ERR(priv->scu)) { 110 dev_err(&pdev->dev, "failed to find SCU regmap\n"); 111 return PTR_ERR(priv->scu); 112 } 113 114 ret = of_reserved_mem_device_init(drm->dev); 115 if (ret) { 116 dev_err(&pdev->dev, 117 "failed to initialize reserved mem: %d\n", ret); 118 return ret; 119 } 120 121 ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32)); 122 if (ret) { 123 dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret); 124 return ret; 125 } 126 127 priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); 128 if (IS_ERR(priv->rst)) { 129 dev_err(&pdev->dev, 130 "missing or invalid reset controller device tree entry"); 131 return PTR_ERR(priv->rst); 132 } 133 reset_control_deassert(priv->rst); 134 135 priv->clk = devm_clk_get(drm->dev, NULL); 136 if (IS_ERR(priv->clk)) { 137 dev_err(&pdev->dev, 138 "missing or invalid clk device tree entry"); 139 return PTR_ERR(priv->clk); 140 } 141 clk_prepare_enable(priv->clk); 142 143 /* Sanitize control registers */ 144 writel(0, priv->base + CRT_CTRL1); 145 writel(0, priv->base + CRT_CTRL2); 146 147 aspeed_gfx_setup_mode_config(drm); 148 149 ret = drm_vblank_init(drm, 1); 150 if (ret < 0) { 151 dev_err(drm->dev, "Failed to initialise vblank\n"); 152 return ret; 153 } 154 155 ret = aspeed_gfx_create_output(drm); 156 if (ret < 0) { 157 dev_err(drm->dev, "Failed to create outputs\n"); 158 return ret; 159 } 160 161 ret = aspeed_gfx_create_pipe(drm); 162 if (ret < 0) { 163 dev_err(drm->dev, "Cannot setup simple display pipe\n"); 164 return ret; 165 } 166 167 ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0), 168 aspeed_gfx_irq_handler, 0, "aspeed gfx", drm); 169 if (ret < 0) { 170 dev_err(drm->dev, "Failed to install IRQ handler\n"); 171 return ret; 172 } 173 174 drm_mode_config_reset(drm); 175 176 drm_fbdev_generic_setup(drm, 32); 177 178 return 0; 179 } 180 181 static void aspeed_gfx_unload(struct drm_device *drm) 182 { 183 drm_kms_helper_poll_fini(drm); 184 drm_mode_config_cleanup(drm); 185 } 186 187 DEFINE_DRM_GEM_CMA_FOPS(fops); 188 189 static struct drm_driver aspeed_gfx_driver = { 190 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 191 .gem_create_object = drm_cma_gem_create_object_default_funcs, 192 .dumb_create = drm_gem_cma_dumb_create, 193 .prime_handle_to_fd = drm_gem_prime_handle_to_fd, 194 .prime_fd_to_handle = drm_gem_prime_fd_to_handle, 195 .gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table, 196 .gem_prime_mmap = drm_gem_prime_mmap, 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 static int aspeed_gfx_probe(struct platform_device *pdev) 211 { 212 struct aspeed_gfx *priv; 213 int ret; 214 215 priv = devm_drm_dev_alloc(&pdev->dev, &aspeed_gfx_driver, 216 struct aspeed_gfx, drm); 217 if (IS_ERR(priv)) 218 return PTR_ERR(priv); 219 220 ret = aspeed_gfx_load(&priv->drm); 221 if (ret) 222 return ret; 223 224 ret = drm_dev_register(&priv->drm, 0); 225 if (ret) 226 goto err_unload; 227 228 return 0; 229 230 err_unload: 231 aspeed_gfx_unload(&priv->drm); 232 233 return ret; 234 } 235 236 static int aspeed_gfx_remove(struct platform_device *pdev) 237 { 238 struct drm_device *drm = platform_get_drvdata(pdev); 239 240 drm_dev_unregister(drm); 241 aspeed_gfx_unload(drm); 242 243 return 0; 244 } 245 246 static struct platform_driver aspeed_gfx_platform_driver = { 247 .probe = aspeed_gfx_probe, 248 .remove = aspeed_gfx_remove, 249 .driver = { 250 .name = "aspeed_gfx", 251 .of_match_table = aspeed_gfx_match, 252 }, 253 }; 254 255 module_platform_driver(aspeed_gfx_platform_driver); 256 257 MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>"); 258 MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver"); 259 MODULE_LICENSE("GPL"); 260