Hello Philipp,
On 13/06/14 18:08, Philipp Zabel wrote:
> This patch allows to use the runtime pm and generic pm domain frameworks
> to completely gate power to the VPU if it is unused. This functionality
> is available on i.MX6.
>
> Signed-off-by: Philipp Zabel <p.za...@pengutronix.de>
> ---
> drivers/media/platform/coda.c | 65
> +++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 60 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/media/platform/coda.c b/drivers/media/platform/coda.c
> index 8321243..f39f693 100644
> --- a/drivers/media/platform/coda.c
> +++ b/drivers/media/platform/coda.c
> @@ -22,6 +22,7 @@
> #include <linux/module.h>
> #include <linux/of_device.h>
> #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> #include <linux/slab.h>
> #include <linux/videodev2.h>
> #include <linux/of.h>
> @@ -2820,6 +2821,13 @@ static int coda_open(struct file *file)
> ctx->reg_idx = idx;
> }
>
> + /* Power up and upload firmware if necessary */
> + ret = pm_runtime_get_sync(&dev->plat_dev->dev);
> + if (ret < 0) {
> + v4l2_err(&dev->v4l2_dev, "failed to power up: %d\n", ret);
> + goto err_pm_get;
> + }
> +
> ret = clk_prepare_enable(dev->clk_per);
> if (ret)
> goto err_clk_per;
> @@ -2889,6 +2897,8 @@ err_ctx_init:
> err_clk_ahb:
> clk_disable_unprepare(dev->clk_per);
> err_clk_per:
> + pm_runtime_put_sync(&dev->plat_dev->dev);
> +err_pm_get:
> v4l2_fh_del(&ctx->fh);
> v4l2_fh_exit(&ctx->fh);
> clear_bit(ctx->idx, &dev->instance_mask);
> @@ -2930,6 +2940,7 @@ static int coda_release(struct file *file)
> v4l2_ctrl_handler_free(&ctx->ctrls);
> clk_disable_unprepare(dev->clk_ahb);
> clk_disable_unprepare(dev->clk_per);
> + pm_runtime_put_sync(&dev->plat_dev->dev);
> v4l2_fh_del(&ctx->fh);
> v4l2_fh_exit(&ctx->fh);
> clear_bit(ctx->idx, &dev->instance_mask);
> @@ -3243,7 +3254,7 @@ static int coda_hw_init(struct coda_dev *dev)
>
> ret = clk_prepare_enable(dev->clk_per);
> if (ret)
> - return ret;
> + goto err_clk_per;
>
> ret = clk_prepare_enable(dev->clk_ahb);
> if (ret)
> @@ -3369,6 +3380,7 @@ static int coda_hw_init(struct coda_dev *dev)
>
> err_clk_ahb:
> clk_disable_unprepare(dev->clk_per);
> +err_clk_per:
> return ret;
> }
>
> @@ -3394,10 +3406,29 @@ static void coda_fw_callback(const struct firmware
> *fw, void *context)
> memcpy(dev->codebuf.vaddr, fw->data, fw->size);
> release_firmware(fw);
>
> - ret = coda_hw_init(dev);
> - if (ret) {
> - v4l2_err(&dev->v4l2_dev, "HW initialization failed\n");
> - return;
> + if (IS_ENABLED(CONFIG_PM_RUNTIME) && pdev->dev.pm_domain) {
How about using the pm_runtime_enabled() helper ? Also why do you need to
be checking dev.pm_domain here and in the resume() callback ? Couldn't it
be done unconditionally ? Why the driver needs to care about the PM domain
existence ?
> + /*
> + * Enabling power temporarily will cause coda_hw_init to be
> + * called via coda_runtime_resume by the pm domain.
> + */
> + ret = pm_runtime_get_sync(&dev->plat_dev->dev);
> + if (ret < 0) {
> + v4l2_err(&dev->v4l2_dev, "failed to power on: %d\n",
> + ret);
> + return;
> + }
> +
> + pm_runtime_put_sync(&dev->plat_dev->dev);
> + } else {
> + /*
> + * If runtime pm is disabled or pm_domain is not set,
> + * initialize once manually.
> + */
> + ret = coda_hw_init(dev);
> + if (ret < 0) {
> + v4l2_err(&dev->v4l2_dev, "HW initialization failed\n");
> + return;
> + }
> }
>
> dev->vfd.fops = &coda_fops,
> @@ -3635,6 +3666,8 @@ static int coda_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, dev);
>
> + pm_runtime_enable(&pdev->dev);
> +
> return coda_firmware_request(dev);
> }
>
> @@ -3645,6 +3678,7 @@ static int coda_remove(struct platform_device *pdev)
> video_unregister_device(&dev->vfd);
> if (dev->m2m_dev)
> v4l2_m2m_release(dev->m2m_dev);
> + pm_runtime_disable(&pdev->dev);
> if (dev->alloc_ctx)
> vb2_dma_contig_cleanup_ctx(dev->alloc_ctx);
> v4l2_device_unregister(&dev->v4l2_dev);
> @@ -3658,6 +3692,26 @@ static int coda_remove(struct platform_device *pdev)
> return 0;
> }
>
> +#ifdef CONFIG_PM_RUNTIME
> +static int coda_runtime_resume(struct device *dev)
> +{
> + struct coda_dev *cdev = dev_get_drvdata(dev);
> + int ret = 0;
> +
> + if (dev->pm_domain) {
> + ret = coda_hw_init(cdev);
> + if (ret)
> + v4l2_err(&cdev->v4l2_dev, "HW initialization failed\n");
> + }
> +
> + return ret;
> +}
> +#endif
--
Regards,
Sylwester
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