drivers/gpu/drm/vc4/vc4_hvs.c

   1 /*
   2  * Copyright (C) 2015 Broadcom
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 /**
  10  * DOC: VC4 HVS module.
  11  *
  12  * The Hardware Video Scaler (HVS) is the piece of hardware that does
  13  * translation, scaling, colorspace conversion, and compositing of
  14  * pixels stored in framebuffers into a FIFO of pixels going out to
  15  * the Pixel Valve (CRTC).  It operates at the system clock rate (the
  16  * system audio clock gate, specifically), which is much higher than
  17  * the pixel clock rate.
  18  *
  19  * There is a single global HVS, with multiple output FIFOs that can
  20  * be consumed by the PVs.  This file just manages the resources for
  21  * the HVS, while the vc4_crtc.c code actually drives HVS setup for
  22  * each CRTC.
  23  */
  24
  25 #include <linux/component.h>
  26 #include "vc4_drv.h"
  27 #include "vc4_regs.h"
  28
  29 #define HVS_REG(reg) { reg, #reg }
  30 static const struct {
  31         u32 reg;
  32         const char *name;
  33 } hvs_regs[] = {
  34         HVS_REG(SCALER_DISPCTRL),
  35         HVS_REG(SCALER_DISPSTAT),
  36         HVS_REG(SCALER_DISPID),
  37         HVS_REG(SCALER_DISPECTRL),
  38         HVS_REG(SCALER_DISPPROF),
  39         HVS_REG(SCALER_DISPDITHER),
  40         HVS_REG(SCALER_DISPEOLN),
  41         HVS_REG(SCALER_DISPLIST0),
  42         HVS_REG(SCALER_DISPLIST1),
  43         HVS_REG(SCALER_DISPLIST2),
  44         HVS_REG(SCALER_DISPLSTAT),
  45         HVS_REG(SCALER_DISPLACT0),
  46         HVS_REG(SCALER_DISPLACT1),
  47         HVS_REG(SCALER_DISPLACT2),
  48         HVS_REG(SCALER_DISPCTRL0),
  49         HVS_REG(SCALER_DISPBKGND0),
  50         HVS_REG(SCALER_DISPSTAT0),
  51         HVS_REG(SCALER_DISPBASE0),
  52         HVS_REG(SCALER_DISPCTRL1),
  53         HVS_REG(SCALER_DISPBKGND1),
  54         HVS_REG(SCALER_DISPSTAT1),
  55         HVS_REG(SCALER_DISPBASE1),
  56         HVS_REG(SCALER_DISPCTRL2),
  57         HVS_REG(SCALER_DISPBKGND2),
  58         HVS_REG(SCALER_DISPSTAT2),
  59         HVS_REG(SCALER_DISPBASE2),
  60         HVS_REG(SCALER_DISPALPHA2),
  61 };
  62
  63 void vc4_hvs_dump_state(struct drm_device *dev)
  64 {
  65         struct vc4_dev *vc4 = to_vc4_dev(dev);
  66         int i;
  67
  68         for (i = 0; i < ARRAY_SIZE(hvs_regs); i++) {
  69                 DRM_INFO("0x%04x (%s): 0x%08x\n",
  70                          hvs_regs[i].reg, hvs_regs[i].name,
  71                          HVS_READ(hvs_regs[i].reg));
  72         }
  73
  74         DRM_INFO("HVS ctx:\n");
  75         for (i = 0; i < 64; i += 4) {
  76                 DRM_INFO("0x%08x (%s): 0x%08x 0x%08x 0x%08x 0x%08x\n",
  77                          i * 4, i < HVS_BOOTLOADER_DLIST_END ? "B" : "D",
  78                          readl((u32 __iomem *)vc4->hvs->dlist + i + 0),
  79                          readl((u32 __iomem *)vc4->hvs->dlist + i + 1),
  80                          readl((u32 __iomem *)vc4->hvs->dlist + i + 2),
  81                          readl((u32 __iomem *)vc4->hvs->dlist + i + 3));
  82         }
  83 }
  84
  85 #ifdef CONFIG_DEBUG_FS
  86 int vc4_hvs_debugfs_regs(struct seq_file *m, void *unused)
  87 {
  88         struct drm_info_node *node = (struct drm_info_node *)m->private;
  89         struct drm_device *dev = node->minor->dev;
  90         struct vc4_dev *vc4 = to_vc4_dev(dev);
  91         int i;
  92
  93         for (i = 0; i < ARRAY_SIZE(hvs_regs); i++) {
  94                 seq_printf(m, "%s (0x%04x): 0x%08x\n",
  95                            hvs_regs[i].name, hvs_regs[i].reg,
  96                            HVS_READ(hvs_regs[i].reg));
  97         }
  98
  99         return 0;
 100 }
 101 #endif
 102
 103 /* The filter kernel is composed of dwords each containing 3 9-bit
 104  * signed integers packed next to each other.
 105  */
 106 #define VC4_INT_TO_COEFF(coeff) (coeff & 0x1ff)
 107 #define VC4_PPF_FILTER_WORD(c0, c1, c2)                         \
 108         ((((c0) & 0x1ff) << 0) |                                \
 109          (((c1) & 0x1ff) << 9) |                                \
 110          (((c2) & 0x1ff) << 18))
 111
 112 /* The whole filter kernel is arranged as the coefficients 0-16 going
 113  * up, then a pad, then 17-31 going down and reversed within the
 114  * dwords.  This means that a linear phase kernel (where it's
 115  * symmetrical at the boundary between 15 and 16) has the last 5
 116  * dwords matching the first 5, but reversed.
 117  */
 118 #define VC4_LINEAR_PHASE_KERNEL(c0, c1, c2, c3, c4, c5, c6, c7, c8,     \
 119                                 c9, c10, c11, c12, c13, c14, c15)       \
 120         {VC4_PPF_FILTER_WORD(c0, c1, c2),                               \
 121          VC4_PPF_FILTER_WORD(c3, c4, c5),                               \
 122          VC4_PPF_FILTER_WORD(c6, c7, c8),                               \
 123          VC4_PPF_FILTER_WORD(c9, c10, c11),                             \
 124          VC4_PPF_FILTER_WORD(c12, c13, c14),                            \
 125          VC4_PPF_FILTER_WORD(c15, c15, 0)}
 126
 127 #define VC4_LINEAR_PHASE_KERNEL_DWORDS 6
 128 #define VC4_KERNEL_DWORDS (VC4_LINEAR_PHASE_KERNEL_DWORDS * 2 - 1)
 129
 130 /* Recommended B=1/3, C=1/3 filter choice from Mitchell/Netravali.
 131  * http://www.cs.utexas.edu/~fussell/courses/cs384g/lectures/mitchell/Mitchell.pdf
 132  */
 133 static const u32 mitchell_netravali_1_3_1_3_kernel[] =
 134         VC4_LINEAR_PHASE_KERNEL(0, -2, -6, -8, -10, -8, -3, 2, 18,
 135                                 50, 82, 119, 155, 187, 213, 227);
 136
 137 static int vc4_hvs_upload_linear_kernel(struct vc4_hvs *hvs,
 138                                         struct drm_mm_node *space,
 139                                         const u32 *kernel)
 140 {
 141         int ret, i;
 142         u32 __iomem *dst_kernel;
 143
 144         ret = drm_mm_insert_node(&hvs->dlist_mm, space, VC4_KERNEL_DWORDS);
 145         if (ret) {
 146                 DRM_ERROR("Failed to allocate space for filter kernel: %d\n",
 147                           ret);
 148                 return ret;
 149         }
 150
 151         dst_kernel = hvs->dlist + space->start;
 152
 153         for (i = 0; i < VC4_KERNEL_DWORDS; i++) {
 154                 if (i < VC4_LINEAR_PHASE_KERNEL_DWORDS)
 155                         writel(kernel[i], &dst_kernel[i]);
 156                 else {
 157                         writel(kernel[VC4_KERNEL_DWORDS - i - 1],
 158                                &dst_kernel[i]);
 159                 }
 160         }
 161
 162         return 0;
 163 }
 164
 165 static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
 166 {
 167         struct platform_device *pdev = to_platform_device(dev);
 168         struct drm_device *drm = dev_get_drvdata(master);
 169         struct vc4_dev *vc4 = drm->dev_private;
 170         struct vc4_hvs *hvs = NULL;
 171         int ret;
 172         u32 dispctrl;
 173
 174         hvs = devm_kzalloc(&pdev->dev, sizeof(*hvs), GFP_KERNEL);
 175         if (!hvs)
 176                 return -ENOMEM;
 177
 178         hvs->pdev = pdev;
 179
 180         hvs->regs = vc4_ioremap_regs(pdev, 0);
 181         if (IS_ERR(hvs->regs))
 182                 return PTR_ERR(hvs->regs);
 183
 184         hvs->dlist = hvs->regs + SCALER_DLIST_START;
 185
 186         spin_lock_init(&hvs->mm_lock);
 187
 188         /* Set up the HVS display list memory manager.  We never
 189          * overwrite the setup from the bootloader (just 128b out of
 190          * our 16K), since we don't want to scramble the screen when
 191          * transitioning from the firmware's boot setup to runtime.
 192          */
 193         drm_mm_init(&hvs->dlist_mm,
 194                     HVS_BOOTLOADER_DLIST_END,
 195                     (SCALER_DLIST_SIZE >> 2) - HVS_BOOTLOADER_DLIST_END);
 196
 197         /* Set up the HVS LBM memory manager.  We could have some more
 198          * complicated data structure that allowed reuse of LBM areas
 199          * between planes when they don't overlap on the screen, but
 200          * for now we just allocate globally.
 201          */
 202         drm_mm_init(&hvs->lbm_mm, 0, 96 * 1024);
 203
 204         /* Upload filter kernels.  We only have the one for now, so we
 205          * keep it around for the lifetime of the driver.
 206          */
 207         ret = vc4_hvs_upload_linear_kernel(hvs,
 208                                            &hvs->mitchell_netravali_filter,
 209                                            mitchell_netravali_1_3_1_3_kernel);
 210         if (ret)
 211                 return ret;
 212
 213         vc4->hvs = hvs;
 214
 215         dispctrl = HVS_READ(SCALER_DISPCTRL);
 216
 217         dispctrl |= SCALER_DISPCTRL_ENABLE;
 218
 219         /* Set DSP3 (PV1) to use HVS channel 2, which would otherwise
 220          * be unused.
 221          */
 222         dispctrl &= ~SCALER_DISPCTRL_DSP3_MUX_MASK;
 223         dispctrl |= VC4_SET_FIELD(2, SCALER_DISPCTRL_DSP3_MUX);
 224
 225         HVS_WRITE(SCALER_DISPCTRL, dispctrl);
 226
 227         return 0;
 228 }
 229
 230 static void vc4_hvs_unbind(struct device *dev, struct device *master,
 231                            void *data)
 232 {
 233         struct drm_device *drm = dev_get_drvdata(master);
 234         struct vc4_dev *vc4 = drm->dev_private;
 235
 236         if (vc4->hvs->mitchell_netravali_filter.allocated)
 237                 drm_mm_remove_node(&vc4->hvs->mitchell_netravali_filter);
 238
 239         drm_mm_takedown(&vc4->hvs->dlist_mm);
 240         drm_mm_takedown(&vc4->hvs->lbm_mm);
 241
 242         vc4->hvs = NULL;
 243 }
 244
 245 static const struct component_ops vc4_hvs_ops = {
 246         .bind   = vc4_hvs_bind,
 247         .unbind = vc4_hvs_unbind,
 248 };
 249
 250 static int vc4_hvs_dev_probe(struct platform_device *pdev)
 251 {
 252         return component_add(&pdev->dev, &vc4_hvs_ops);
 253 }
 254
 255 static int vc4_hvs_dev_remove(struct platform_device *pdev)
 256 {
 257         component_del(&pdev->dev, &vc4_hvs_ops);
 258         return 0;
 259 }
 260
 261 static const struct of_device_id vc4_hvs_dt_match[] = {
 262         { .compatible = "brcm,bcm2835-hvs" },
 263         {}
 264 };
 265
 266 struct platform_driver vc4_hvs_driver = {
 267         .probe = vc4_hvs_dev_probe,
 268         .remove = vc4_hvs_dev_remove,
 269         .driver = {
 270                 .name = "vc4_hvs",
 271                 .of_match_table = vc4_hvs_dt_match,
 272         },
 273 };