[PATCH v4 3/5] media: atmel-isc: Enable the clocks during probe

[Wenyou Yang]

To meet the relationship, enable the HCLOCK and ispck during the
device probe, "isc_pck frequency is less than or equal to isc_ispck,
and isc_ispck is greater than or equal to HCLOCK."
Meanwhile, call the pm_runtime_enable() in the right place.

Signed-off-by: Wenyou Yang <wenyou.y...@microchip.com>
---

Changes in v4:
 - Move pm_runtime_enable() call from the complete callback to the
   end of probe.
 - Call pm_runtime_get_sync() and pm_runtime_put_sync() in
   ->is_enabled() callbacks.
 - Call clk_disable_unprepare() in ->remove callback.

Changes in v3: None
Changes in v2: None

 drivers/media/platform/atmel/atmel-isc.c | 34 ++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/drivers/media/platform/atmel/atmel-isc.c 
b/drivers/media/platform/atmel/atmel-isc.c
index 5f8228fc9c8d..a44a66ad2c02 100644
--- a/drivers/media/platform/atmel/atmel-isc.c
+++ b/drivers/media/platform/atmel/atmel-isc.c
@@ -389,8 +389,14 @@ static int isc_clk_is_enabled(struct clk_hw *hw)
        struct isc_clk *isc_clk = to_isc_clk(hw);
        u32 status;
 
+       if (isc_clk->id == ISC_MCK)
+               pm_runtime_get_sync(isc_clk->dev);
+
        regmap_read(isc_clk->regmap, ISC_CLKSR, &status);
 
+       if (isc_clk->id == ISC_MCK)
+               pm_runtime_put_sync(isc_clk->dev);
+
        return status & ISC_CLK(isc_clk->id) ? 1 : 0;
 }
 
@@ -1866,25 +1872,37 @@ static int atmel_isc_probe(struct platform_device *pdev)
                return ret;
        }
 
+       ret = clk_prepare_enable(isc->hclock);
+       if (ret) {
+               dev_err(dev, "failed to enable hclock: %d\n", ret);
+               return ret;
+       }
+
        ret = isc_clk_init(isc);
        if (ret) {
                dev_err(dev, "failed to init isc clock: %d\n", ret);
-               goto clean_isc_clk;
+               goto unprepare_hclk;
        }
 
        isc->ispck = isc->isc_clks[ISC_ISPCK].clk;
 
+       ret = clk_prepare_enable(isc->ispck);
+       if (ret) {
+               dev_err(dev, "failed to enable ispck: %d\n", ret);
+               goto unprepare_hclk;
+       }
+
        /* ispck should be greater or equal to hclock */
        ret = clk_set_rate(isc->ispck, clk_get_rate(isc->hclock));
        if (ret) {
                dev_err(dev, "failed to set ispck rate: %d\n", ret);
-               goto clean_isc_clk;
+               goto unprepare_clk;
        }
 
        ret = v4l2_device_register(dev, &isc->v4l2_dev);
        if (ret) {
                dev_err(dev, "unable to register v4l2 device.\n");
-               goto clean_isc_clk;
+               goto unprepare_clk;
        }
 
        ret = isc_parse_dt(dev, isc);
@@ -1917,7 +1935,9 @@ static int atmel_isc_probe(struct platform_device *pdev)
                        break;
        }
 
+       pm_runtime_set_active(dev);
        pm_runtime_enable(dev);
+       pm_request_idle(dev);
 
        return 0;
 
@@ -1927,7 +1947,11 @@ static int atmel_isc_probe(struct platform_device *pdev)
 unregister_v4l2_device:
        v4l2_device_unregister(&isc->v4l2_dev);
 
-clean_isc_clk:
+unprepare_clk:
+       clk_disable_unprepare(isc->ispck);
+unprepare_hclk:
+       clk_disable_unprepare(isc->hclock);
+
        isc_clk_cleanup(isc);
 
        return ret;
@@ -1938,6 +1962,8 @@ static int atmel_isc_remove(struct platform_device *pdev)
        struct isc_device *isc = platform_get_drvdata(pdev);
 
        pm_runtime_disable(&pdev->dev);
+       clk_disable_unprepare(isc->ispck);
+       clk_disable_unprepare(isc->hclock);
 
        isc_subdev_cleanup(isc);
 
-- 
2.13.0