[PATCH v3 2/2] media: cedrus: Implement runtime PM

From: Samuel Holland
Date: Sat May 09 2020 - 16:12:28 EST


From: Jernej Skrabec <jernej.skrabec@xxxxxxxx>

This allows the VE clocks and PLL_VE to be disabled most of the time.
A runtime PM reference is held while streaming.

Signed-off-by: Jernej Skrabec <jernej.skrabec@xxxxxxxx>
Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
Tested-by: Jernej Skrabec <jernej.skrabec@xxxxxxxx>
Reviewed-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
---

v2: moved PM reference to cedrus_{start,stop}_streaming, based on an
earlier patch by Jernej Skrabec. Removes the need for autosuspend.
I tested this with running 2x v4l2-request-test in parallel.
v3: changed authorship to Jernej, collected tags

---
drivers/staging/media/sunxi/cedrus/cedrus.c | 7 ++
.../staging/media/sunxi/cedrus/cedrus_hw.c | 106 ++++++++++++------
.../staging/media/sunxi/cedrus/cedrus_hw.h | 3 +
.../staging/media/sunxi/cedrus/cedrus_video.c | 33 ++++--
4 files changed, 104 insertions(+), 45 deletions(-)

diff --git a/drivers/staging/media/sunxi/cedrus/cedrus.c b/drivers/staging/media/sunxi/cedrus/cedrus.c
index 05a85517ff60..bc27f9430eeb 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus.c
@@ -16,6 +16,7 @@
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/pm.h>

#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
@@ -551,12 +552,18 @@ static const struct of_device_id cedrus_dt_match[] = {
};
MODULE_DEVICE_TABLE(of, cedrus_dt_match);

+static const struct dev_pm_ops cedrus_dev_pm_ops = {
+ SET_RUNTIME_PM_OPS(cedrus_hw_suspend,
+ cedrus_hw_resume, NULL)
+};
+
static struct platform_driver cedrus_driver = {
.probe = cedrus_probe,
.remove = cedrus_remove,
.driver = {
.name = CEDRUS_NAME,
.of_match_table = of_match_ptr(cedrus_dt_match),
+ .pm = &cedrus_dev_pm_ops,
},
};
module_platform_driver(cedrus_driver);
diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
index daf5f244f93b..1744e6fcc999 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
@@ -19,6 +19,7 @@
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
+#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/soc/sunxi/sunxi_sram.h>
@@ -140,6 +141,64 @@ static irqreturn_t cedrus_irq(int irq, void *data)
return IRQ_HANDLED;
}

+int cedrus_hw_suspend(struct device *device)
+{
+ struct cedrus_dev *dev = dev_get_drvdata(device);
+
+ reset_control_assert(dev->rstc);
+
+ clk_disable_unprepare(dev->ram_clk);
+ clk_disable_unprepare(dev->mod_clk);
+ clk_disable_unprepare(dev->ahb_clk);
+
+ return 0;
+}
+
+int cedrus_hw_resume(struct device *device)
+{
+ struct cedrus_dev *dev = dev_get_drvdata(device);
+ int ret;
+
+ ret = clk_prepare_enable(dev->ahb_clk);
+ if (ret) {
+ dev_err(dev->dev, "Failed to enable AHB clock\n");
+
+ return ret;
+ }
+
+ ret = clk_prepare_enable(dev->mod_clk);
+ if (ret) {
+ dev_err(dev->dev, "Failed to enable MOD clock\n");
+
+ goto err_ahb_clk;
+ }
+
+ ret = clk_prepare_enable(dev->ram_clk);
+ if (ret) {
+ dev_err(dev->dev, "Failed to enable RAM clock\n");
+
+ goto err_mod_clk;
+ }
+
+ ret = reset_control_reset(dev->rstc);
+ if (ret) {
+ dev_err(dev->dev, "Failed to apply reset\n");
+
+ goto err_ram_clk;
+ }
+
+ return 0;
+
+err_ram_clk:
+ clk_disable_unprepare(dev->ram_clk);
+err_mod_clk:
+ clk_disable_unprepare(dev->mod_clk);
+err_ahb_clk:
+ clk_disable_unprepare(dev->ahb_clk);
+
+ return ret;
+}
+
int cedrus_hw_probe(struct cedrus_dev *dev)
{
const struct cedrus_variant *variant;
@@ -236,42 +295,17 @@ int cedrus_hw_probe(struct cedrus_dev *dev)
goto err_sram;
}

- ret = clk_prepare_enable(dev->ahb_clk);
- if (ret) {
- dev_err(dev->dev, "Failed to enable AHB clock\n");
-
- goto err_sram;
- }
-
- ret = clk_prepare_enable(dev->mod_clk);
- if (ret) {
- dev_err(dev->dev, "Failed to enable MOD clock\n");
-
- goto err_ahb_clk;
- }
-
- ret = clk_prepare_enable(dev->ram_clk);
- if (ret) {
- dev_err(dev->dev, "Failed to enable RAM clock\n");
-
- goto err_mod_clk;
- }
-
- ret = reset_control_reset(dev->rstc);
- if (ret) {
- dev_err(dev->dev, "Failed to apply reset\n");
-
- goto err_ram_clk;
+ pm_runtime_enable(dev->dev);
+ if (!pm_runtime_enabled(dev->dev)) {
+ ret = cedrus_hw_resume(dev->dev);
+ if (ret)
+ goto err_pm;
}

return 0;

-err_ram_clk:
- clk_disable_unprepare(dev->ram_clk);
-err_mod_clk:
- clk_disable_unprepare(dev->mod_clk);
-err_ahb_clk:
- clk_disable_unprepare(dev->ahb_clk);
+err_pm:
+ pm_runtime_disable(dev->dev);
err_sram:
sunxi_sram_release(dev->dev);
err_mem:
@@ -282,11 +316,9 @@ int cedrus_hw_probe(struct cedrus_dev *dev)

void cedrus_hw_remove(struct cedrus_dev *dev)
{
- reset_control_assert(dev->rstc);
-
- clk_disable_unprepare(dev->ram_clk);
- clk_disable_unprepare(dev->mod_clk);
- clk_disable_unprepare(dev->ahb_clk);
+ pm_runtime_disable(dev->dev);
+ if (!pm_runtime_status_suspended(dev->dev))
+ cedrus_hw_suspend(dev->dev);

sunxi_sram_release(dev->dev);

diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.h b/drivers/staging/media/sunxi/cedrus/cedrus_hw.h
index 604ff932fbf5..45f641f0bfa2 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus_hw.h
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.h
@@ -22,6 +22,9 @@ void cedrus_engine_disable(struct cedrus_dev *dev);
void cedrus_dst_format_set(struct cedrus_dev *dev,
struct v4l2_pix_format *fmt);

+int cedrus_hw_suspend(struct device *device);
+int cedrus_hw_resume(struct device *device);
+
int cedrus_hw_probe(struct cedrus_dev *dev);
void cedrus_hw_remove(struct cedrus_dev *dev);

diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_video.c b/drivers/staging/media/sunxi/cedrus/cedrus_video.c
index ed3f511f066f..16d82309e7b6 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus_video.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_video.c
@@ -13,6 +13,8 @@
* Marek Szyprowski, <m.szyprowski@xxxxxxxxxxx>
*/

+#include <linux/pm_runtime.h>
+
#include <media/videobuf2-dma-contig.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
@@ -450,12 +452,24 @@ static int cedrus_start_streaming(struct vb2_queue *vq, unsigned int count)
return -EINVAL;
}

- if (V4L2_TYPE_IS_OUTPUT(vq->type) &&
- dev->dec_ops[ctx->current_codec]->start)
- ret = dev->dec_ops[ctx->current_codec]->start(ctx);
+ if (V4L2_TYPE_IS_OUTPUT(vq->type)) {
+ ret = pm_runtime_get_sync(dev->dev);
+ if (ret < 0)
+ goto err_cleanup;

- if (ret)
- cedrus_queue_cleanup(vq, VB2_BUF_STATE_QUEUED);
+ if (dev->dec_ops[ctx->current_codec]->start) {
+ ret = dev->dec_ops[ctx->current_codec]->start(ctx);
+ if (ret)
+ goto err_pm;
+ }
+ }
+
+ return 0;
+
+err_pm:
+ pm_runtime_put(dev->dev);
+err_cleanup:
+ cedrus_queue_cleanup(vq, VB2_BUF_STATE_QUEUED);

return ret;
}
@@ -465,9 +479,12 @@ static void cedrus_stop_streaming(struct vb2_queue *vq)
struct cedrus_ctx *ctx = vb2_get_drv_priv(vq);
struct cedrus_dev *dev = ctx->dev;

- if (V4L2_TYPE_IS_OUTPUT(vq->type) &&
- dev->dec_ops[ctx->current_codec]->stop)
- dev->dec_ops[ctx->current_codec]->stop(ctx);
+ if (V4L2_TYPE_IS_OUTPUT(vq->type)) {
+ if (dev->dec_ops[ctx->current_codec]->stop)
+ dev->dec_ops[ctx->current_codec]->stop(ctx);
+
+ pm_runtime_put(dev->dev);
+ }

cedrus_queue_cleanup(vq, VB2_BUF_STATE_ERROR);
}
--
2.24.1