@@ -13,6 +13,7 @@
#include <linux/component.h>
#include <linux/delay.h>
#include <linux/i2c.h>
+#include <linux/interconnect.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
@@ -73,6 +74,7 @@ enum mixer_flag_bits {
MXR_BIT_INTERLACE,
MXR_BIT_VP_ENABLED,
MXR_BIT_HAS_SCLK,
+ MXR_BIT_REQUEST_BW,
};
static const uint32_t mixer_formats[] = {
@@ -99,6 +101,13 @@ struct mixer_context {
struct exynos_drm_plane planes[MIXER_WIN_NR];
unsigned long flags;
+ struct icc_path *icc_path;
+ /* memory bandwidth on the interconnect bus in B/s */
+ unsigned long icc_bandwidth;
+ /* mutex protecting @icc_bandwidth */
+ struct mutex icc_lock;
+ struct work_struct work;
+
int irq;
void __iomem *mixer_regs;
void __iomem *vp_regs;
@@ -754,6 +763,9 @@ static irqreturn_t mixer_irq_handler(int irq, void *arg)
val |= MXR_INT_CLEAR_VSYNC;
val &= ~MXR_INT_STATUS_VSYNC;
+ if (test_and_clear_bit(MXR_BIT_REQUEST_BW, &ctx->flags))
+ schedule_work(&ctx->work);
+
/* interlace scan need to check shadow register */
if (test_bit(MXR_BIT_INTERLACE, &ctx->flags)
&& !mixer_is_synced(ctx))
@@ -934,6 +946,76 @@ static void mixer_disable_vblank(struct exynos_drm_crtc *crtc)
mixer_reg_writemask(mixer_ctx, MXR_INT_EN, 0, MXR_INT_EN_VSYNC);
}
+/**
+ * mixer_get_memory_bandwidth - calculate memory bandwidth for current crtc mode
+ * @crtc: a crtc with DRM mode to calculate the bandwidth for
+ *
+ * Return: memory bandwidth in B/s
+ *
+ * This function returns memory bandwidth calculated as a sum of amount of data
+ * per second for each plane. The calculation is based on maximum possible pixel
+ * resolution for a plane so as to avoid different bandwidth request per each
+ * video frame. The formula used for calculation for each plane is:
+ *
+ * bw = width * height * frame_rate / interlace / (hor_subs * vert_subs)
+ *
+ * where:
+ * - width, height - (DRM mode) video frame width and height in pixels,
+ * - frame_rate - DRM mode frame refresh rate,
+ * - interlace: 1 - in case of progressive and 2 in case of interlaced video,
+ * - hor_subs, vert_subs - accordingly horizontal and vertical pixel
+ * subsampling for a plane.
+ */
+static unsigned int mixer_get_memory_bandwidth(struct exynos_drm_crtc *crtc)
+{
+ struct drm_display_mode *mode = &crtc->base.state->adjusted_mode;
+ struct mixer_context *ctx = crtc->ctx;
+ unsigned long bw, bandwidth = 0;
+ int i, j, sub;
+
+ for (i = 0; i < MIXER_WIN_NR; i++) {
+ struct drm_plane *plane = &ctx->planes[i].base;
+ const struct drm_format_info *format;
+
+ if (plane->state && plane->state->crtc && plane->state->fb) {
+ format = plane->state->fb->format;
+ bw = mode->hdisplay * mode->vdisplay *
+ drm_mode_vrefresh(mode);
+ if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+ bw /= 2;
+ for (j = 0; j < format->num_planes; j++) {
+ sub = j ? (format->vsub * format->hsub) : 1;
+ bandwidth += format->cpp[j] * bw / sub;
+ }
+ }
+ }
+
+ return bandwidth;
+}
+
+static void mixer_set_icc_bandwidth(struct mixer_context *ctx,
+ unsigned long bandwidth)
+{
+ u32 avg_bw, peak_bw;
+
+ /* add 20% safety margin */
+ bandwidth = bandwidth / 4 * 5;
+
+ avg_bw = peak_bw = Bps_to_icc(bandwidth);
+ icc_set_bw(ctx->icc_path, avg_bw, peak_bw);
+
+ dev_dbg(ctx->dev, "safe bandwidth %lu Bps\n", bandwidth);
+}
+
+static void mixer_icc_request_fn(struct work_struct *work)
+{
+ struct mixer_context *ctx = container_of(work, struct mixer_context,
+ work);
+ mutex_lock(&ctx->icc_lock);
+ mixer_set_icc_bandwidth(ctx, ctx->icc_bandwidth);
+ mutex_unlock(&ctx->icc_lock);
+}
+
static void mixer_atomic_begin(struct exynos_drm_crtc *crtc)
{
struct mixer_context *ctx = crtc->ctx;
@@ -980,12 +1062,35 @@ static void mixer_disable_plane(struct exynos_drm_crtc *crtc,
static void mixer_atomic_flush(struct exynos_drm_crtc *crtc)
{
- struct mixer_context *mixer_ctx = crtc->ctx;
+ struct mixer_context *ctx = crtc->ctx;
+ int bw, prev_bw;
- if (!test_bit(MXR_BIT_POWERED, &mixer_ctx->flags))
+ if (!test_bit(MXR_BIT_POWERED, &ctx->flags))
return;
- mixer_enable_sync(mixer_ctx);
+ /*
+ * Request necessary bandwidth on the interconnects. If new
+ * bandwidth is greater than current value set the new value
+ * immediately. Otherwise request lower bandwidth only after
+ * VSYNC, after the HW has actually switched to new video
+ * frame settings.
+ */
+ if (ctx->icc_path) {
+ bw = mixer_get_memory_bandwidth(crtc);
+
+ mutex_lock(&ctx->icc_lock);
+ prev_bw = ctx->icc_bandwidth;
+ ctx->icc_bandwidth = bw;
+
+ if (bw > prev_bw)
+ mixer_set_icc_bandwidth(ctx, bw);
+ else if (bw < prev_bw)
+ set_bit(MXR_BIT_REQUEST_BW, &ctx->flags);
+
+ mutex_unlock(&ctx->icc_lock);
+ }
+
+ mixer_enable_sync(ctx);
exynos_crtc_handle_event(crtc);
}
@@ -1036,6 +1141,8 @@ static void mixer_atomic_disable(struct exynos_drm_crtc *crtc)
pm_runtime_put(ctx->dev);
+ mixer_set_icc_bandwidth(ctx, 0);
+
clear_bit(MXR_BIT_POWERED, &ctx->flags);
}
@@ -1223,19 +1330,33 @@ static int mixer_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
const struct mixer_drv_data *drv;
struct mixer_context *ctx;
+ struct icc_path *path;
int ret;
+ /*
+ * Returns NULL if CONFIG_INTERCONNECT is disabled.
+ * May return ERR_PTR(-EPROBE_DEFER).
+ */
+ path = of_icc_get(dev, NULL);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+
ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
if (!ctx) {
DRM_DEV_ERROR(dev, "failed to alloc mixer context.\n");
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto err;
}
drv = of_device_get_match_data(dev);
+ INIT_WORK(&ctx->work, mixer_icc_request_fn);
+ mutex_init(&ctx->icc_lock);
+
ctx->pdev = pdev;
ctx->dev = dev;
ctx->mxr_ver = drv->version;
+ ctx->icc_path = path;
if (drv->is_vp_enabled)
__set_bit(MXR_BIT_VP_ENABLED, &ctx->flags);
@@ -1247,17 +1368,26 @@ static int mixer_probe(struct platform_device *pdev)
pm_runtime_enable(dev);
ret = component_add(&pdev->dev, &mixer_component_ops);
- if (ret)
+ if (ret) {
pm_runtime_disable(dev);
-
+ goto err;
+ }
+ return 0;
+err:
+ icc_put(path);
return ret;
}
static int mixer_remove(struct platform_device *pdev)
{
- pm_runtime_disable(&pdev->dev);
+ struct device *dev = &pdev->dev;
+ struct mixer_context *ctx = dev_get_drvdata(dev);
+
+ pm_runtime_disable(dev);
+
+ component_del(dev, &mixer_component_ops);
- component_del(&pdev->dev, &mixer_component_ops);
+ icc_put(ctx->icc_path);
return 0;
}