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 <[email protected]> --- drivers/dma/pl330.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index c3bd3584f261..e499bb118f0a 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2627,6 +2627,46 @@ 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); + + pm_runtime_disable(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); + + pm_runtime_enable(dev); + + 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 +2893,7 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
