drivers/gpu/drm/vc4/vc4_hvs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2015 Broadcom
   4  */
   5
   6 /**
   7  * DOC: VC4 HVS module.
   8  *
   9  * The Hardware Video Scaler (HVS) is the piece of hardware that does
  10  * translation, scaling, colorspace conversion, and compositing of
  11  * pixels stored in framebuffers into a FIFO of pixels going out to
  12  * the Pixel Valve (CRTC).  It operates at the system clock rate (the
  13  * system audio clock gate, specifically), which is much higher than
  14  * the pixel clock rate.
  15  *
  16  * There is a single global HVS, with multiple output FIFOs that can
  17  * be consumed by the PVs.  This file just manages the resources for
  18  * the HVS, while the vc4_crtc.c code actually drives HVS setup for
  19  * each CRTC.
  20  */
  21
  22 #include <linux/component.h>
  23 #include <linux/platform_device.h>
  24
  25 #include <drm/drm_atomic_helper.h>
  26
  27 #include "vc4_drv.h"
  28 #include "vc4_regs.h"
  29
  30 static const struct debugfs_reg32 hvs_regs[] = {
  31         VC4_REG32(SCALER_DISPCTRL),
  32         VC4_REG32(SCALER_DISPSTAT),
  33         VC4_REG32(SCALER_DISPID),
  34         VC4_REG32(SCALER_DISPECTRL),
  35         VC4_REG32(SCALER_DISPPROF),
  36         VC4_REG32(SCALER_DISPDITHER),
  37         VC4_REG32(SCALER_DISPEOLN),
  38         VC4_REG32(SCALER_DISPLIST0),
  39         VC4_REG32(SCALER_DISPLIST1),
  40         VC4_REG32(SCALER_DISPLIST2),
  41         VC4_REG32(SCALER_DISPLSTAT),
  42         VC4_REG32(SCALER_DISPLACT0),
  43         VC4_REG32(SCALER_DISPLACT1),
  44         VC4_REG32(SCALER_DISPLACT2),
  45         VC4_REG32(SCALER_DISPCTRL0),
  46         VC4_REG32(SCALER_DISPBKGND0),
  47         VC4_REG32(SCALER_DISPSTAT0),
  48         VC4_REG32(SCALER_DISPBASE0),
  49         VC4_REG32(SCALER_DISPCTRL1),
  50         VC4_REG32(SCALER_DISPBKGND1),
  51         VC4_REG32(SCALER_DISPSTAT1),
  52         VC4_REG32(SCALER_DISPBASE1),
  53         VC4_REG32(SCALER_DISPCTRL2),
  54         VC4_REG32(SCALER_DISPBKGND2),
  55         VC4_REG32(SCALER_DISPSTAT2),
  56         VC4_REG32(SCALER_DISPBASE2),
  57         VC4_REG32(SCALER_DISPALPHA2),
  58         VC4_REG32(SCALER_OLEDOFFS),
  59         VC4_REG32(SCALER_OLEDCOEF0),
  60         VC4_REG32(SCALER_OLEDCOEF1),
  61         VC4_REG32(SCALER_OLEDCOEF2),
  62 };
  63
  64 void vc4_hvs_dump_state(struct drm_device *dev)
  65 {
  66         struct vc4_dev *vc4 = to_vc4_dev(dev);
  67         struct drm_printer p = drm_info_printer(&vc4->hvs->pdev->dev);
  68         int i;
  69
  70         drm_print_regset32(&p, &vc4->hvs->regset);
  71
  72         DRM_INFO("HVS ctx:\n");
  73         for (i = 0; i < 64; i += 4) {
  74                 DRM_INFO("0x%08x (%s): 0x%08x 0x%08x 0x%08x 0x%08x\n",
  75                          i * 4, i < HVS_BOOTLOADER_DLIST_END ? "B" : "D",
  76                          readl((u32 __iomem *)vc4->hvs->dlist + i + 0),
  77                          readl((u32 __iomem *)vc4->hvs->dlist + i + 1),
  78                          readl((u32 __iomem *)vc4->hvs->dlist + i + 2),
  79                          readl((u32 __iomem *)vc4->hvs->dlist + i + 3));
  80         }
  81 }
  82
  83 static int vc4_hvs_debugfs_underrun(struct seq_file *m, void *data)
  84 {
  85         struct drm_info_node *node = m->private;
  86         struct drm_device *dev = node->minor->dev;
  87         struct vc4_dev *vc4 = to_vc4_dev(dev);
  88         struct drm_printer p = drm_seq_file_printer(m);
  89
  90         drm_printf(&p, "%d\n", atomic_read(&vc4->underrun));
  91
  92         return 0;
  93 }
  94
  95 /* The filter kernel is composed of dwords each containing 3 9-bit
  96  * signed integers packed next to each other.
  97  */
  98 #define VC4_INT_TO_COEFF(coeff) (coeff & 0x1ff)
  99 #define VC4_PPF_FILTER_WORD(c0, c1, c2)                         \
 100         ((((c0) & 0x1ff) << 0) |                                \
 101          (((c1) & 0x1ff) << 9) |                                \
 102          (((c2) & 0x1ff) << 18))
 103
 104 /* The whole filter kernel is arranged as the coefficients 0-16 going
 105  * up, then a pad, then 17-31 going down and reversed within the
 106  * dwords.  This means that a linear phase kernel (where it's
 107  * symmetrical at the boundary between 15 and 16) has the last 5
 108  * dwords matching the first 5, but reversed.
 109  */
 110 #define VC4_LINEAR_PHASE_KERNEL(c0, c1, c2, c3, c4, c5, c6, c7, c8,     \
 111                                 c9, c10, c11, c12, c13, c14, c15)       \
 112         {VC4_PPF_FILTER_WORD(c0, c1, c2),                               \
 113          VC4_PPF_FILTER_WORD(c3, c4, c5),                               \
 114          VC4_PPF_FILTER_WORD(c6, c7, c8),                               \
 115          VC4_PPF_FILTER_WORD(c9, c10, c11),                             \
 116          VC4_PPF_FILTER_WORD(c12, c13, c14),                            \
 117          VC4_PPF_FILTER_WORD(c15, c15, 0)}
 118
 119 #define VC4_LINEAR_PHASE_KERNEL_DWORDS 6
 120 #define VC4_KERNEL_DWORDS (VC4_LINEAR_PHASE_KERNEL_DWORDS * 2 - 1)
 121
 122 /* Recommended B=1/3, C=1/3 filter choice from Mitchell/Netravali.
 123  * http://www.cs.utexas.edu/~fussell/courses/cs384g/lectures/mitchell/Mitchell.pdf
 124  */
 125 static const u32 mitchell_netravali_1_3_1_3_kernel[] =
 126         VC4_LINEAR_PHASE_KERNEL(0, -2, -6, -8, -10, -8, -3, 2, 18,
 127                                 50, 82, 119, 155, 187, 213, 227);
 128
 129 static int vc4_hvs_upload_linear_kernel(struct vc4_hvs *hvs,
 130                                         struct drm_mm_node *space,
 131                                         const u32 *kernel)
 132 {
 133         int ret, i;
 134         u32 __iomem *dst_kernel;
 135
 136         ret = drm_mm_insert_node(&hvs->dlist_mm, space, VC4_KERNEL_DWORDS);
 137         if (ret) {
 138                 DRM_ERROR("Failed to allocate space for filter kernel: %d\n",
 139                           ret);
 140                 return ret;
 141         }
 142
 143         dst_kernel = hvs->dlist + space->start;
 144
 145         for (i = 0; i < VC4_KERNEL_DWORDS; i++) {
 146                 if (i < VC4_LINEAR_PHASE_KERNEL_DWORDS)
 147                         writel(kernel[i], &dst_kernel[i]);
 148                 else {
 149                         writel(kernel[VC4_KERNEL_DWORDS - i - 1],
 150                                &dst_kernel[i]);
 151                 }
 152         }
 153
 154         return 0;
 155 }
 156
 157 void vc4_hvs_mask_underrun(struct drm_device *dev, int channel)
 158 {
 159         struct vc4_dev *vc4 = to_vc4_dev(dev);
 160         u32 dispctrl = HVS_READ(SCALER_DISPCTRL);
 161
 162         dispctrl &= ~SCALER_DISPCTRL_DSPEISLUR(channel);
 163
 164         HVS_WRITE(SCALER_DISPCTRL, dispctrl);
 165 }
 166
 167 void vc4_hvs_unmask_underrun(struct drm_device *dev, int channel)
 168 {
 169         struct vc4_dev *vc4 = to_vc4_dev(dev);
 170         u32 dispctrl = HVS_READ(SCALER_DISPCTRL);
 171
 172         dispctrl |= SCALER_DISPCTRL_DSPEISLUR(channel);
 173
 174         HVS_WRITE(SCALER_DISPSTAT,
 175                   SCALER_DISPSTAT_EUFLOW(channel));
 176         HVS_WRITE(SCALER_DISPCTRL, dispctrl);
 177 }
 178
 179 static void vc4_hvs_report_underrun(struct drm_device *dev)
 180 {
 181         struct vc4_dev *vc4 = to_vc4_dev(dev);
 182
 183         atomic_inc(&vc4->underrun);
 184         DRM_DEV_ERROR(dev->dev, "HVS underrun\n");
 185 }
 186
 187 static irqreturn_t vc4_hvs_irq_handler(int irq, void *data)
 188 {
 189         struct drm_device *dev = data;
 190         struct vc4_dev *vc4 = to_vc4_dev(dev);
 191         irqreturn_t irqret = IRQ_NONE;
 192         int channel;
 193         u32 control;
 194         u32 status;
 195
 196         status = HVS_READ(SCALER_DISPSTAT);
 197         control = HVS_READ(SCALER_DISPCTRL);
 198
 199         for (channel = 0; channel < SCALER_CHANNELS_COUNT; channel++) {
 200                 /* Interrupt masking is not always honored, so check it here. */
 201                 if (status & SCALER_DISPSTAT_EUFLOW(channel) &&
 202                     control & SCALER_DISPCTRL_DSPEISLUR(channel)) {
 203                         vc4_hvs_mask_underrun(dev, channel);
 204                         vc4_hvs_report_underrun(dev);
 205
 206                         irqret = IRQ_HANDLED;
 207                 }
 208         }
 209
 210         /* Clear every per-channel interrupt flag. */
 211         HVS_WRITE(SCALER_DISPSTAT, SCALER_DISPSTAT_IRQMASK(0) |
 212                                    SCALER_DISPSTAT_IRQMASK(1) |
 213                                    SCALER_DISPSTAT_IRQMASK(2));
 214
 215         return irqret;
 216 }
 217
 218 static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
 219 {
 220         struct platform_device *pdev = to_platform_device(dev);
 221         struct drm_device *drm = dev_get_drvdata(master);
 222         struct vc4_dev *vc4 = drm->dev_private;
 223         struct vc4_hvs *hvs = NULL;
 224         int ret;
 225         u32 dispctrl;
 226
 227         hvs = devm_kzalloc(&pdev->dev, sizeof(*hvs), GFP_KERNEL);
 228         if (!hvs)
 229                 return -ENOMEM;
 230
 231         hvs->pdev = pdev;
 232
 233         hvs->regs = vc4_ioremap_regs(pdev, 0);
 234         if (IS_ERR(hvs->regs))
 235                 return PTR_ERR(hvs->regs);
 236
 237         hvs->regset.base = hvs->regs;
 238         hvs->regset.regs = hvs_regs;
 239         hvs->regset.nregs = ARRAY_SIZE(hvs_regs);
 240
 241         hvs->dlist = hvs->regs + SCALER_DLIST_START;
 242
 243         spin_lock_init(&hvs->mm_lock);
 244
 245         /* Set up the HVS display list memory manager.  We never
 246          * overwrite the setup from the bootloader (just 128b out of
 247          * our 16K), since we don't want to scramble the screen when
 248          * transitioning from the firmware's boot setup to runtime.
 249          */
 250         drm_mm_init(&hvs->dlist_mm,
 251                     HVS_BOOTLOADER_DLIST_END,
 252                     (SCALER_DLIST_SIZE >> 2) - HVS_BOOTLOADER_DLIST_END);
 253
 254         /* Set up the HVS LBM memory manager.  We could have some more
 255          * complicated data structure that allowed reuse of LBM areas
 256          * between planes when they don't overlap on the screen, but
 257          * for now we just allocate globally.
 258          */
 259         drm_mm_init(&hvs->lbm_mm, 0, 96 * 1024);
 260
 261         /* Upload filter kernels.  We only have the one for now, so we
 262          * keep it around for the lifetime of the driver.
 263          */
 264         ret = vc4_hvs_upload_linear_kernel(hvs,
 265                                            &hvs->mitchell_netravali_filter,
 266                                            mitchell_netravali_1_3_1_3_kernel);
 267         if (ret)
 268                 return ret;
 269
 270         vc4->hvs = hvs;
 271
 272         dispctrl = HVS_READ(SCALER_DISPCTRL);
 273
 274         dispctrl |= SCALER_DISPCTRL_ENABLE;
 275         dispctrl |= SCALER_DISPCTRL_DISPEIRQ(0) |
 276                     SCALER_DISPCTRL_DISPEIRQ(1) |
 277                     SCALER_DISPCTRL_DISPEIRQ(2);
 278
 279         /* Set DSP3 (PV1) to use HVS channel 2, which would otherwise
 280          * be unused.
 281          */
 282         dispctrl &= ~SCALER_DISPCTRL_DSP3_MUX_MASK;
 283         dispctrl &= ~(SCALER_DISPCTRL_DMAEIRQ |
 284                       SCALER_DISPCTRL_SLVWREIRQ |
 285                       SCALER_DISPCTRL_SLVRDEIRQ |
 286                       SCALER_DISPCTRL_DSPEIEOF(0) |
 287                       SCALER_DISPCTRL_DSPEIEOF(1) |
 288                       SCALER_DISPCTRL_DSPEIEOF(2) |
 289                       SCALER_DISPCTRL_DSPEIEOLN(0) |
 290                       SCALER_DISPCTRL_DSPEIEOLN(1) |
 291                       SCALER_DISPCTRL_DSPEIEOLN(2) |
 292                       SCALER_DISPCTRL_DSPEISLUR(0) |
 293                       SCALER_DISPCTRL_DSPEISLUR(1) |
 294                       SCALER_DISPCTRL_DSPEISLUR(2) |
 295                       SCALER_DISPCTRL_SCLEIRQ);
 296         dispctrl |= VC4_SET_FIELD(2, SCALER_DISPCTRL_DSP3_MUX);
 297
 298         HVS_WRITE(SCALER_DISPCTRL, dispctrl);
 299
 300         ret = devm_request_irq(dev, platform_get_irq(pdev, 0),
 301                                vc4_hvs_irq_handler, 0, "vc4 hvs", drm);
 302         if (ret)
 303                 return ret;
 304
 305         vc4_debugfs_add_regset32(drm, "hvs_regs", &hvs->regset);
 306         vc4_debugfs_add_file(drm, "hvs_underrun", vc4_hvs_debugfs_underrun,
 307                              NULL);
 308
 309         return 0;
 310 }
 311
 312 static void vc4_hvs_unbind(struct device *dev, struct device *master,
 313                            void *data)
 314 {
 315         struct drm_device *drm = dev_get_drvdata(master);
 316         struct vc4_dev *vc4 = drm->dev_private;
 317
 318         if (drm_mm_node_allocated(&vc4->hvs->mitchell_netravali_filter))
 319                 drm_mm_remove_node(&vc4->hvs->mitchell_netravali_filter);
 320
 321         drm_mm_takedown(&vc4->hvs->dlist_mm);
 322         drm_mm_takedown(&vc4->hvs->lbm_mm);
 323
 324         vc4->hvs = NULL;
 325 }
 326
 327 static const struct component_ops vc4_hvs_ops = {
 328         .bind   = vc4_hvs_bind,
 329         .unbind = vc4_hvs_unbind,
 330 };
 331
 332 static int vc4_hvs_dev_probe(struct platform_device *pdev)
 333 {
 334         return component_add(&pdev->dev, &vc4_hvs_ops);
 335 }
 336
 337 static int vc4_hvs_dev_remove(struct platform_device *pdev)
 338 {
 339         component_del(&pdev->dev, &vc4_hvs_ops);
 340         return 0;
 341 }
 342
 343 static const struct of_device_id vc4_hvs_dt_match[] = {
 344         { .compatible = "brcm,bcm2835-hvs" },
 345         {}
 346 };
 347
 348 struct platform_driver vc4_hvs_driver = {
 349         .probe = vc4_hvs_dev_probe,
 350         .remove = vc4_hvs_dev_remove,
 351         .driver = {
 352                 .name = "vc4_hvs",
 353                 .of_match_table = vc4_hvs_dt_match,
 354         },
 355 };