Subject: [PATCH] ARM: omap: edma: add suspend suspend/resume hooks

From: [email-masked] (Gururaja Hebbar)
Date: Thu, 3 Oct 2013 12:13:53 +0530

On Tuesday 01 October 2013 07:21 PM, Daniel Mack wrote:
> This patch makes the edma driver resume correctly after suspend. Tested
> on an AM33xx platform with cyclic audio streams.

I believe you have confirmed below are the only registers/fields which
will lose context across suspend/resume

> 
> The code was shamelessly taken from an ancient BSP tree.

Can you pick and merge below commit as well..

http://arago-project.org/git/projects/?p=linux-am33x.git;a=commitdiff;h=b81bf04091986fa3893f31955564594567be3b61

Thanks & regards
Gururaja

> 
> Signed-off-by: Daniel Mack <[email-masked]>
> ---
>  arch/arm/common/edma.c | 133 +++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 133 insertions(+)
> 
> diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
> index 2a72169..d787f14 100644
> --- a/arch/arm/common/edma.c
> +++ b/arch/arm/common/edma.c
> @@ -258,6 +258,20 @@ struct edma {
>  				void *data);
>  		void *data;
>  	} intr_data[EDMA_MAX_DMACH];
> +
> +	struct {
> +		struct edmacc_param *prm_set;
> +		unsigned int *ch_map;               /* 64 registers */
> +		unsigned int *que_num;              /* 8 registers */
> +		unsigned int sh_esr;
> +		unsigned int sh_esrh;
> +		unsigned int sh_eesr;
> +		unsigned int sh_eesrh;
> +		unsigned int sh_iesr;
> +		unsigned int sh_iesrh;
> +		unsigned int que_tc_map;
> +		unsigned int que_pri;
> +	} context;
>  };
>  
>  static struct edma *edma_cc[EDMA_MAX_CC];
> @@ -1655,6 +1669,16 @@ static int edma_probe(struct platform_device *pdev)
>  			memcpy_toio(edmacc_regs_base[j] + PARM_OFFSET(i),
>  					&dummy_paramset, PARM_SIZE);
>  
> +		/* resume context */
> +		edma_cc[j]->context.prm_set =
> +			kzalloc((sizeof(struct edmacc_param) *
> +				 edma_cc[j]->num_slots), GFP_KERNEL);
> +		edma_cc[j]->context.ch_map =
> +			kzalloc((sizeof(unsigned int) *
> +				 edma_cc[j]->num_channels), GFP_KERNEL);
> +		edma_cc[j]->context.que_num =
> +			kzalloc((sizeof(unsigned int) * 8), GFP_KERNEL);
> +
>  		/* Mark all channels as unused */
>  		memset(edma_cc[j]->edma_unused, 0xff,
>  			sizeof(edma_cc[j]->edma_unused));
> @@ -1762,6 +1786,114 @@ static int edma_probe(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +static int edma_pm_suspend(struct device *dev)
> +{
> +	int i, j;
> +
> +	pm_runtime_get_sync(dev);
> +
> +	for (i = 0; i < arch_num_cc; i++) {
> +		struct edma *ecc = edma_cc[i];
> +
> +		/* backup channel data */
> +		for (j = 0; j < ecc->num_channels; j++)
> +			ecc->context.ch_map[j] =
> +				edma_read_array(i, EDMA_DCHMAP, j);
> +
> +		/* backup DMA Queue Number */
> +		for (j = 0; j < 8; j++)
> +			ecc->context.que_num[j] =
> +				edma_read_array(i, EDMA_DMAQNUM, j);
> +
> +		/* backup DMA shadow Event Set data */
> +		ecc->context.sh_esr = edma_shadow0_read_array(i, SH_ESR, 0);
> +		ecc->context.sh_esrh = edma_shadow0_read_array(i, SH_ESR, 1);
> +
> +		/* backup DMA Shadow Event Enable Set data */
> +		ecc->context.sh_eesr =
> +			edma_shadow0_read_array(i, SH_EER, 0);
> +		ecc->context.sh_eesrh =
> +			edma_shadow0_read_array(i, SH_EER, 1);
> +
> +		/* backup DMA Shadow Interrupt Enable Set data */
> +		ecc->context.sh_iesr =
> +			edma_shadow0_read_array(i, SH_IER, 0);
> +		ecc->context.sh_iesrh =
> +			edma_shadow0_read_array(i, SH_IER, 1);
> +
> +		ecc->context.que_tc_map = edma_read(i, EDMA_QUETCMAP);
> +
> +		/* backup DMA Queue Priority data */
> +		ecc->context.que_pri = edma_read(i, EDMA_QUEPRI);
> +
> +		/* backup paramset */
> +		for (j = 0; j < ecc->num_slots; j++)
> +			memcpy_fromio(&ecc->context.prm_set[j],
> +				      edmacc_regs_base[i] + PARM_OFFSET(j),
> +				      PARM_SIZE);
> +	}
> +
> +	pm_runtime_put_sync(dev);
> +
> +	return 0;
> +}
> +
> +static int edma_pm_resume(struct device *dev)
> +{
> +	int i, j;
> +
> +	pm_runtime_get_sync(dev);
> +
> +	for (i = 0; i < arch_num_cc; i++) {
> +		struct edma *ecc = edma_cc[i];
> +
> +		/* restore channel data */
> +		for (j = 0; j < ecc->num_channels; j++) {
> +			edma_write_array(i, EDMA_DCHMAP, j,
> +					 ecc->context.ch_map[j]);
> +		}
> +
> +		/* restore DMA Queue Number */
> +		for (j = 0; j < 8; j++) {
> +			edma_write_array(i, EDMA_DMAQNUM, j,
> +					 ecc->context.que_num[j]);
> +		}
> +
> +		/* restore DMA shadow Event Set data */
> +		edma_shadow0_write_array(i, SH_ESR, 0, ecc->context.sh_esr);
> +		edma_shadow0_write_array(i, SH_ESR, 1, ecc->context.sh_esrh);
> +
> +		/* restore DMA Shadow Event Enable Set data */
> +		edma_shadow0_write_array(i, SH_EESR, 0,
> +					 ecc->context.sh_eesr);
> +		edma_shadow0_write_array(i, SH_EESR, 1,
> +					 ecc->context.sh_eesrh);
> +
> +		/* restore DMA Shadow Interrupt Enable Set data */
> +		edma_shadow0_write_array(i, SH_IESR, 0,
> +					 ecc->context.sh_iesr);
> +		edma_shadow0_write_array(i, SH_IESR, 1,
> +					 ecc->context.sh_iesrh);
> +
> +		edma_write(i, EDMA_QUETCMAP, ecc->context.que_tc_map);
> +
> +		/* restore DMA Queue Priority data */
> +		edma_write(i, EDMA_QUEPRI, ecc->context.que_pri);
> +
> +		/* restore paramset */
> +		for (j = 0; j < ecc->num_slots; j++) {
> +			memcpy_toio(edmacc_regs_base[i] + PARM_OFFSET(j),
> +				    &ecc->context.prm_set[j], PARM_SIZE);
> +		}
> +	}
> +
> +	pm_runtime_put_sync(dev);
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(edma_pm_ops, edma_pm_suspend, edma_pm_resume);
> +
>  static const struct of_device_id edma_of_ids[] = {
>  	{ .compatible = "ti,edma3", },
>  	{}
> @@ -1770,6 +1902,7 @@ static const struct of_device_id edma_of_ids[] = {
>  static struct platform_driver edma_driver = {
>  	.driver = {
>  		.name	= "edma",
> +		.pm	= &edma_pm_ops,
>  		.of_match_table = edma_of_ids,
>  	},
>  	.probe = edma_probe,
>