[PATCH v4.1 1/4] drm/rockchip: vop: export line flag function

Yakir Yang
2016-07-15T10:55:20Z

VOP have integrated a hardware counter which indicate the exact display
line that vop is scanning. And if we're interested in a specific line,
we can set the line number to vop line_flag register, and then vop would
generate a line_flag interrupt for it.

For example eDP PSR function is interested in the vertical blanking
period, then driver could set the line number to zero.

This patch have exported a symbol that allow other driver to listen the
line flag event with given timeout limit:
- rockchip_drm_wait_line_flag()

Signed-off-by: Yakir Yang <ykk@rock-chips.com>
---
Changes in v4.1:
- Remove the completion_done() check in irq handler (Sean)

Changes in v4:
- Avoid the weird behavior in rockchip_drm_wait_line_flag(). (Sean)
- Make line_flag_num_x to an array. (Sean)
- Remove the unused vop_cfg_done() in vop_line_flag_irq_enable(). (Stephane, reviewed in Google gerrit)
[https://chromium-review.googlesource.com/#/c/349084/33/drivers/gpu/drm/rockchip/rockchip_drm_vop.c@466]

Changes in v3:
- Export the 'rockchip_drm_wait_line_flag' symbol, and document it.
- Add 'line_flag_num_0' for RK3288/RK3036
- Remove the notify for waiting line_flag event (Daniel)

Changes in v2:
- Introduce in v2, split VOP line flag changes out

drivers/gpu/drm/rockchip/rockchip_drm_drv.h | 3 +
drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 117 ++++++++++++++++++++++++++++
drivers/gpu/drm/rockchip/rockchip_drm_vop.h | 2 +
drivers/gpu/drm/rockchip/rockchip_vop_reg.c | 4 +
4 files changed, 126 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.h b/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
index ea39329..239b830 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
@@ -70,4 +70,7 @@ int rockchip_drm_dma_attach_device(struct drm_device *drm_dev,
struct device *dev);
void rockchip_drm_dma_detach_device(struct drm_device *drm_dev,
struct device *dev);
+int rockchip_drm_wait_line_flag(struct drm_crtc *crtc, unsigned int line_num,
+ unsigned int mstimeout);
+
#endif /* _ROCKCHIP_DRM_DRV_H_ */
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index c8a62a8..8a4f36e 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -121,6 +121,8 @@ struct vop {
/* protected by dev->event_lock */
struct drm_pending_vblank_event *event;

+ struct completion line_flag_completion;
+
const struct vop_data *data;

uint32_t *regsbak;
@@ -431,6 +433,71 @@ static void vop_dsp_hold_valid_irq_disable(struct vop *vop)
spin_unlock_irqrestore(&vop->irq_lock, flags);
}

+/*
+ * (1) each frame starts at the start of the Vsync pulse which is signaled by
+ * the "FRAME_SYNC" interrupt.
+ * (2) the active data region of each frame ends at dsp_vact_end
+ * (3) we should program this same number (dsp_vact_end) into dsp_line_frag_num,
+ * to get "LINE_FLAG" interrupt at the end of the active on screen data.
+ *
+ * VOP_INTR_CTRL0.dsp_line_frag_num = VOP_DSP_VACT_ST_END.dsp_vact_end
+ * Interrupts
+ * LINE_FLAG -------------------------------+
+ * FRAME_SYNC ----+ |
+ * | |
+ * v v
+ * | Vsync | Vbp | Vactive | Vfp |
+ * ^ ^ ^ ^
+ * | | | |
+ * | | | |
+ * dsp_vs_end ------------+ | | | VOP_DSP_VTOTAL_VS_END
+ * dsp_vact_start --------------+ | | VOP_DSP_VACT_ST_END
+ * dsp_vact_end ----------------------------+ | VOP_DSP_VACT_ST_END
+ * dsp_total -------------------------------------+ VOP_DSP_VTOTAL_VS_END
+ */
+static bool vop_line_flag_irq_is_enabled(struct vop *vop)
+{
+ uint32_t line_flag_irq;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vop->irq_lock, flags);
+
+ line_flag_irq = VOP_INTR_GET_TYPE(vop, enable, LINE_FLAG_INTR);
+
+ spin_unlock_irqrestore(&vop->irq_lock, flags);
+
+ return !!line_flag_irq;
+}
+
+static void vop_line_flag_irq_enable(struct vop *vop, int line_num)
+{
+ unsigned long flags;
+
+ if (WARN_ON(!vop->is_enabled))
+ return;
+
+ spin_lock_irqsave(&vop->irq_lock, flags);
+
+ VOP_CTRL_SET(vop, line_flag_num[0], line_num);
+ VOP_INTR_SET_TYPE(vop, enable, LINE_FLAG_INTR, 1);
+
+ spin_unlock_irqrestore(&vop->irq_lock, flags);
+}
+
+static void vop_line_flag_irq_disable(struct vop *vop)
+{
+ unsigned long flags;
+
+ if (WARN_ON(!vop->is_enabled))
+ return;
+
+ spin_lock_irqsave(&vop->irq_lock, flags);
+
+ VOP_INTR_SET_TYPE(vop, enable, LINE_FLAG_INTR, 0);
+
+ spin_unlock_irqrestore(&vop->irq_lock, flags);
+}
+
static void vop_enable(struct drm_crtc *crtc)
{
struct vop *vop = to_vop(crtc);
@@ -1157,6 +1224,12 @@ static irqreturn_t vop_isr(int irq, void *data)
ret = IRQ_HANDLED;
}

+ if (active_irqs & LINE_FLAG_INTR) {
+ complete(&vop->line_flag_completion);
+ active_irqs &= ~LINE_FLAG_INTR;
+ ret = IRQ_HANDLED;
+ }
+
if (active_irqs & FS_INTR) {
drm_crtc_handle_vblank(crtc);
vop_handle_vblank(vop);
@@ -1255,6 +1328,7 @@ static int vop_create_crtc(struct vop *vop)

init_completion(&vop->dsp_hold_completion);
init_completion(&vop->wait_update_complete);
+ init_completion(&vop->line_flag_completion);
crtc->port = port;
rockchip_register_crtc_funcs(crtc, &private_crtc_funcs);

@@ -1411,6 +1485,49 @@ static void vop_win_init(struct vop *vop)
}
}

+/**
+ * rockchip_drm_wait_line_flag - acqiure the give line flag event
+ * @crtc: CRTC to enable line flag
+ * @line_num: interested line number
+ * @mstimeout: millisecond for timeout
+ *
+ * Driver would hold here until the interested line flag interrupt have
+ * happened or timeout to wait.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int rockchip_drm_wait_line_flag(struct drm_crtc *crtc, unsigned int line_num,
+ unsigned int mstimeout)
+{
+ struct vop *vop = to_vop(crtc);
+ unsigned long jiffies_left;
+
+ if (!crtc || !vop->is_enabled)
+ return -ENODEV;
+
+ if (line_num > crtc->mode.vtotal || mstimeout <= 0)
+ return -EINVAL;
+
+ if (vop_line_flag_irq_is_enabled(vop))
+ return -EBUSY;
+
+ reinit_completion(&vop->line_flag_completion);
+ vop_line_flag_irq_enable(vop, line_num);
+
+ jiffies_left = wait_for_completion_timeout(&vop->line_flag_completion,
+ msecs_to_jiffies(mstimeout));
+ vop_line_flag_irq_disable(vop);
+
+ if (jiffies_left == 0) {
+ dev_err(vop->dev, "Timeout waiting for IRQ\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(rockchip_drm_wait_line_flag);
+
static int vop_bind(struct device *dev, struct device *master, void *data)
{
struct platform_device *pdev = to_platform_device(dev);
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
index ff4f52e..1dbc526 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
@@ -61,6 +61,8 @@ struct vop_ctrl {
struct vop_reg hpost_st_end;
struct vop_reg vpost_st_end;

+ struct vop_reg line_flag_num[2];
+
struct vop_reg cfg_done;
};

diff --git a/drivers/gpu/drm/rockchip/rockchip_vop_reg.c b/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
index 6f42e56..eea8427 100644
--- a/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
+++ b/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
@@ -122,6 +122,7 @@ static const struct vop_ctrl rk3036_ctrl_data = {
.hact_st_end = VOP_REG(RK3036_DSP_HACT_ST_END, 0x1fff1fff, 0),
.vtotal_pw = VOP_REG(RK3036_DSP_VTOTAL_VS_END, 0x1fff1fff, 0),
.vact_st_end = VOP_REG(RK3036_DSP_VACT_ST_END, 0x1fff1fff, 0),
+ .line_flag_num[0] = VOP_REG(RK3036_INT_STATUS, 0xfff, 12),
.cfg_done = VOP_REG(RK3036_REG_CFG_DONE, 0x1, 0),
};

@@ -221,6 +222,7 @@ static const struct vop_ctrl rk3288_ctrl_data = {
.vact_st_end = VOP_REG(RK3288_DSP_VACT_ST_END, 0x1fff1fff, 0),
.hpost_st_end = VOP_REG(RK3288_POST_DSP_HACT_INFO, 0x1fff1fff, 0),
.vpost_st_end = VOP_REG(RK3288_POST_DSP_VACT_INFO, 0x1fff1fff, 0),
+ .line_flag_num[0] = VOP_REG(RK3288_INTR_CTRL0, 0x1fff, 12),
.cfg_done = VOP_REG(RK3288_REG_CFG_DONE, 0x1, 0),
};

@@ -299,6 +301,8 @@ static const struct vop_ctrl rk3399_ctrl_data = {
.vact_st_end = VOP_REG(RK3399_DSP_VACT_ST_END, 0x1fff1fff, 0),
.hpost_st_end = VOP_REG(RK3399_POST_DSP_HACT_INFO, 0x1fff1fff, 0),
.vpost_st_end = VOP_REG(RK3399_POST_DSP_VACT_INFO, 0x1fff1fff, 0),
+ .line_flag_num[0] = VOP_REG(RK3399_LINE_FLAG, 0xffff, 0),
+ .line_flag_num[1] = VOP_REG(RK3399_LINE_FLAG, 0xffff, 16),
.cfg_done = VOP_REG_MASK(RK3399_REG_CFG_DONE, 0x1, 0),
};

--
1.9.1