[PATCHv4 2/6] dmaengine: mv_xor: add suspend/resume support

[vinod.koul@intel.com (Vinod Koul)]

On Wed, Jul 08, 2015 at 04:28:15PM +0200, Thomas Petazzoni wrote:
> This commit adds suspend/resume support to the mv_xor driver. The
> config and interrupt mask registers must be saved and restored, and
> upon resume, the MBus windows configuration must also be done again.
> 
> Tested on Armada 388 GP, with a RAID 5 array, accessed before and
> after a suspend to RAM cycle.
> 
> Based on work from Ofer Heifetz and Lior Amsalem.
> 
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> ---
>  drivers/dma/mv_xor.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/dma/mv_xor.h |  1 +
>  2 files changed, 48 insertions(+)
> 
> diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
> index f1325f6..0a3ddc2 100644
> --- a/drivers/dma/mv_xor.c
> +++ b/drivers/dma/mv_xor.c
> @@ -1121,6 +1121,51 @@ mv_xor_conf_mbus_windows(struct mv_xor_device *xordev,
>  	writel(0, base + WINDOW_OVERRIDE_CTRL(1));
>  }
>  
> +static int mv_xor_suspend(struct platform_device *pdev, pm_message_t state)
> +{
> +	struct mv_xor_device *xordev = platform_get_drvdata(pdev);
> +	int i;
> +
> +	for (i = 0; i < MV_XOR_MAX_CHANNELS; i++) {
> +		struct mv_xor_chan *mv_chan = xordev->channels[i];
> +
> +		if (!mv_chan)
> +			continue;
> +
> +		mv_chan->saved_config_reg =
> +			readl_relaxed(XOR_CONFIG(mv_chan));
> +		mv_chan->saved_int_mask_reg =
> +			readl_relaxed(XOR_INTR_MASK(mv_chan));
this sound fine, but I am missing the suspension of the channel. If a
transfer was active while suspend was invoked then how would this work?

-- 
~Vinod

> +	}
> +
> +	return 0;
> +}
> +
> +static int mv_xor_resume(struct platform_device *dev)
> +{
> +	struct mv_xor_device *xordev = platform_get_drvdata(dev);
> +	const struct mbus_dram_target_info *dram;
> +	int i;
> +
> +	for (i = 0; i < MV_XOR_MAX_CHANNELS; i++) {
> +		struct mv_xor_chan *mv_chan = xordev->channels[i];
> +
> +		if (!mv_chan)
> +			continue;
> +
> +		writel_relaxed(mv_chan->saved_config_reg,
> +			       XOR_CONFIG(mv_chan));
> +		writel_relaxed(mv_chan->saved_int_mask_reg,
> +			       XOR_INTR_MASK(mv_chan));
> +	}
> +
> +	dram = mv_mbus_dram_info();
> +	if (dram)
> +		mv_xor_conf_mbus_windows(xordev, dram);
> +
> +	return 0;
> +}
> +
>  static const struct of_device_id mv_xor_dt_ids[] = {
>  	{ .compatible = "marvell,orion-xor", .data = (void *)XOR_MODE_IN_REG },
>  	{ .compatible = "marvell,armada-380-xor", .data = (void *)XOR_MODE_IN_DESC },
> @@ -1284,6 +1329,8 @@ static int mv_xor_remove(struct platform_device *pdev)
>  static struct platform_driver mv_xor_driver = {
>  	.probe		= mv_xor_probe,
>  	.remove		= mv_xor_remove,
> +	.suspend        = mv_xor_suspend,
> +	.resume         = mv_xor_resume,
>  	.driver		= {
>  		.name	        = MV_XOR_NAME,
>  		.of_match_table = of_match_ptr(mv_xor_dt_ids),
> diff --git a/drivers/dma/mv_xor.h b/drivers/dma/mv_xor.h
> index b7455b4..41a2e8d 100644
> --- a/drivers/dma/mv_xor.h
> +++ b/drivers/dma/mv_xor.h
> @@ -126,6 +126,7 @@ struct mv_xor_chan {
>  	char			dummy_src[MV_XOR_MIN_BYTE_COUNT];
>  	char			dummy_dst[MV_XOR_MIN_BYTE_COUNT];
>  	dma_addr_t		dummy_src_addr, dummy_dst_addr;
> +	u32                     saved_config_reg, saved_int_mask_reg;
>  };
>  
>  /**
> -- 
> 2.4.5
> 

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