[PATCH] media: cedrus: Implement runtime PM

Samuel Holland
2020-04-08T01:00:07Z

This allows the VE clocks and PLL_VE to be disabled most of the time.

Since the device is stateless, each frame gets a separate runtime PM
reference. Enable autosuspend so the PM callbacks are not run before and
after every frame.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

I tested this with v4l2-request-test. I don't have the setup to do
anything more complicated at the moment.

---
drivers/staging/media/sunxi/cedrus/cedrus.c | 7 ++
.../staging/media/sunxi/cedrus/cedrus_hw.c | 115 ++++++++++++------
.../staging/media/sunxi/cedrus/cedrus_hw.h | 3 +
3 files changed, 88 insertions(+), 37 deletions(-)

diff --git a/drivers/staging/media/sunxi/cedrus/cedrus.c b/drivers/staging/media/sunxi/cedrus/cedrus.c
index 3fad5edccd17..9aa1fc8a6c26 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>
@@ -474,6 +475,11 @@ static int cedrus_remove(struct platform_device *pdev)
return 0;
}

+static const struct dev_pm_ops cedrus_dev_pm_ops = {
+ SET_RUNTIME_PM_OPS(cedrus_hw_suspend,
+ cedrus_hw_resume, NULL)
+};
+
static const struct cedrus_variant sun4i_a10_cedrus_variant = {
.mod_rate = 320000000,
};
@@ -559,6 +565,7 @@ static struct platform_driver cedrus_driver = {
.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..b84814d5afe4 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>
@@ -63,6 +64,8 @@ int cedrus_engine_enable(struct cedrus_ctx *ctx, enum cedrus_codec codec)
if (ctx->src_fmt.width > 2048)
reg |= VE_MODE_PIC_WIDTH_MORE_2048;

+ pm_runtime_get_sync(ctx->dev->dev);
+
cedrus_write(ctx->dev, VE_MODE, reg);

return 0;
@@ -71,6 +74,9 @@ int cedrus_engine_enable(struct cedrus_ctx *ctx, enum cedrus_codec codec)
void cedrus_engine_disable(struct cedrus_dev *dev)
{
cedrus_write(dev, VE_MODE, VE_MODE_DISABLED);
+
+ pm_runtime_mark_last_busy(dev->dev);
+ pm_runtime_put_autosuspend(dev->dev);
}

void cedrus_dst_format_set(struct cedrus_dev *dev,
@@ -134,12 +140,72 @@ static irqreturn_t cedrus_irq(int irq, void *data)
else
state = VB2_BUF_STATE_DONE;

+ cedrus_engine_disable(dev);
+
v4l2_m2m_buf_done_and_job_finish(ctx->dev->m2m_dev, ctx->fh.m2m_ctx,
state);

return IRQ_HANDLED;
}

+int cedrus_hw_resume(struct device *d)
+{
+ struct cedrus_dev *dev = dev_get_drvdata(d);
+ 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_suspend(struct device *d)
+{
+ struct cedrus_dev *dev = dev_get_drvdata(d);
+
+ 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_probe(struct cedrus_dev *dev)
{
const struct cedrus_variant *variant;
@@ -236,42 +302,19 @@ 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_set_autosuspend_delay(dev->dev, 1000);
+ pm_runtime_use_autosuspend(dev->dev);
+ 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 +325,9 @@ 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..17822b470a1e 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_resume(struct device *dev);
+int cedrus_hw_suspend(struct device *dev);
+
int cedrus_hw_probe(struct cedrus_dev *dev);
void cedrus_hw_remove(struct cedrus_dev *dev);

--
2.24.1