Messages in this thread Patch in this message | | | From | Krzysztof Kozlowski <> | Subject | [PATCH v11 5/6] dmaengine: pl330: Add PM sleep support | Date | Wed, 12 Nov 2014 15:32:27 +0100 |
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Add system suspend/resume capabilities to the pl330 driver so the amba bus clock could be also unprepared to conserve energy.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> --- drivers/dma/pl330.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+)
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index c3bd3584f261..fd71777fc565 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2627,6 +2627,42 @@ static int pl330_dma_device_slave_caps(struct dma_chan *dchan, return 0; } +/* + * Runtime PM callbacks are provided by amba/bus.c driver. + * + * It is assumed here that IRQ safe runtime PM is chosen in probe and amba + * bus driver will only disable/enable the clock in runtime PM callbacks. + */ +static int __maybe_unused pl330_suspend(struct device *dev) +{ + struct amba_device *pcdev = to_amba_device(dev); + + if (!pm_runtime_status_suspended(dev)) { + /* amba did not disable the clock */ + amba_pclk_disable(pcdev); + } + amba_pclk_unprepare(pcdev); + + return 0; +} + +static int __maybe_unused pl330_resume(struct device *dev) +{ + struct amba_device *pcdev = to_amba_device(dev); + int ret; + + ret = amba_pclk_prepare(pcdev); + if (ret) + return ret; + + if (!pm_runtime_status_suspended(dev)) + ret = amba_pclk_enable(pcdev); + + return ret; +} + +static SIMPLE_DEV_PM_OPS(pl330_pm, pl330_suspend, pl330_resume); + static int pl330_probe(struct amba_device *adev, const struct amba_id *id) { @@ -2853,6 +2889,7 @@ static struct amba_driver pl330_driver = { .drv = { .owner = THIS_MODULE, .name = "dma-pl330", + .pm = &pl330_pm, }, .id_table = pl330_ids, .probe = pl330_probe, -- 1.9.1
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