[PATCH v3 0/4] dmaengine: rcar-dmac: use of_data and add dma-channel-mask support

[PATCH v3 0/4] dmaengine: rcar-dmac: use of_data and add dma-channel-mask support

[Yoshihiro Shimoda]

This patch series is based on the latest slave-dma.git / next branch.

Changes from v2:
 - Rebase the latest slave-dma.git / next branch (In other words,
   this patch series doesn't depend any other branches.
 - Cherry-picked a patch which is contained in v5.3-rc8 to solve any
   dependency. (I'm not sure whether this is a right way or not...)
  https://patchwork.kernel.org/project/linux-renesas-soc/list/?series=169317

Changes from v1:
 - Combine two patch series into this patch series.
https://patchwork.kernel.org/project/linux-renesas-soc/list/?series=166457&state=*
https://patchwork.kernel.org/project/linux-renesas-soc/list/?series=166457&state=*
 - Remove a patch because updated patch is already merged into
   the latest slave-dma.git / fixes branch as described above.
 - Add Reviewed-by tags into all patches.
 - Rename a member of rcar_dmac_of_data.
 - Just ignore the return value of of_property_read_u32() for dma-channel-mask.


Yoshihiro Shimoda (4):
  dmaengine: rcar-dmac: Fix DMACHCLR handling if iommu is mapped
  dmaengine: rcar-dmac: Use of_data values instead of a macro
  dmaengine: rcar-dmac: Use devm_platform_ioremap_resource()
  dmaengine: rcar-dmac: Add dma-channel-mask property support

 drivers/dma/sh/rcar-dmac.c | 71 +++++++++++++++++++++++++++++++++++-----------
 1 file changed, 55 insertions(+), 16 deletions(-)

-- 
2.7.4

[PATCH v3 1/4] dmaengine: rcar-dmac: Fix DMACHCLR handling if iommu is mapped

[Yoshihiro Shimoda]

The commit 20c169aceb45 ("dmaengine: rcar-dmac: clear pertinence
number of channels") forgets to clear the last channel by
DMACHCLR in rcar_dmac_init() (and doesn't need to clear the first
channel) if iommu is mapped to the device. So, this patch fixes it
by using "channels_mask" bitfield.

Note that the hardware and driver don't support more than 32 bits
in DMACHCLR register anyway, so this patch should reject more than
32 channels in rcar_dmac_parse_of().

Fixes: 20c169aceb459575 ("dmaengine: rcar-dmac: clear pertinence number of channels")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/1567424643-26629-1-git-send-email-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
(cherry picked from commit cf24aac38698bfa1d021afd3883df3c4c65143a4)
[just cherry-picked it for slave-dma/next]
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 drivers/dma/sh/rcar-dmac.c | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index eb6f231..3993ab6 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -192,6 +192,7 @@ struct rcar_dmac_chan {
  * @iomem: remapped I/O memory base
  * @n_channels: number of available channels
  * @channels: array of DMAC channels
+ * @channels_mask: bitfield of which DMA channels are managed by this driver
  * @modules: bitmask of client modules in use
  */
 struct rcar_dmac {
@@ -202,6 +203,7 @@ struct rcar_dmac {
 
 	unsigned int n_channels;
 	struct rcar_dmac_chan *channels;
+	unsigned int channels_mask;
 
 	DECLARE_BITMAP(modules, 256);
 };
@@ -438,7 +440,7 @@ static int rcar_dmac_init(struct rcar_dmac *dmac)
 	u16 dmaor;
 
 	/* Clear all channels and enable the DMAC globally. */
-	rcar_dmac_write(dmac, RCAR_DMACHCLR, GENMASK(dmac->n_channels - 1, 0));
+	rcar_dmac_write(dmac, RCAR_DMACHCLR, dmac->channels_mask);
 	rcar_dmac_write(dmac, RCAR_DMAOR,
 			RCAR_DMAOR_PRI_FIXED | RCAR_DMAOR_DME);
 
@@ -814,6 +816,9 @@ static void rcar_dmac_stop_all_chan(struct rcar_dmac *dmac)
 	for (i = 0; i < dmac->n_channels; ++i) {
 		struct rcar_dmac_chan *chan = &dmac->channels[i];
 
+		if (!(dmac->channels_mask & BIT(i)))
+			continue;
+
 		/* Stop and reinitialize the channel. */
 		spin_lock_irq(&chan->lock);
 		rcar_dmac_chan_halt(chan);
@@ -1774,6 +1779,8 @@ static int rcar_dmac_chan_probe(struct rcar_dmac *dmac,
 	return 0;
 }
 
+#define RCAR_DMAC_MAX_CHANNELS	32
+
 static int rcar_dmac_parse_of(struct device *dev, struct rcar_dmac *dmac)
 {
 	struct device_node *np = dev->of_node;
@@ -1785,12 +1792,16 @@ static int rcar_dmac_parse_of(struct device *dev, struct rcar_dmac *dmac)
 		return ret;
 	}
 
-	if (dmac->n_channels <= 0 || dmac->n_channels >= 100) {
+	/* The hardware and driver don't support more than 32 bits in CHCLR */
+	if (dmac->n_channels <= 0 ||
+	    dmac->n_channels >= RCAR_DMAC_MAX_CHANNELS) {
 		dev_err(dev, "invalid number of channels %u\n",
 			dmac->n_channels);
 		return -EINVAL;
 	}
 
+	dmac->channels_mask = GENMASK(dmac->n_channels - 1, 0);
+
 	return 0;
 }
 
@@ -1800,7 +1811,6 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 		DMA_SLAVE_BUSWIDTH_2_BYTES | DMA_SLAVE_BUSWIDTH_4_BYTES |
 		DMA_SLAVE_BUSWIDTH_8_BYTES | DMA_SLAVE_BUSWIDTH_16_BYTES |
 		DMA_SLAVE_BUSWIDTH_32_BYTES | DMA_SLAVE_BUSWIDTH_64_BYTES;
-	unsigned int channels_offset = 0;
 	struct dma_device *engine;
 	struct rcar_dmac *dmac;
 	struct resource *mem;
@@ -1829,10 +1839,8 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 	 * level we can't disable it selectively, so ignore channel 0 for now if
 	 * the device is part of an IOMMU group.
 	 */
-	if (device_iommu_mapped(&pdev->dev)) {
-		dmac->n_channels--;
-		channels_offset = 1;
-	}
+	if (device_iommu_mapped(&pdev->dev))
+		dmac->channels_mask &= ~BIT(0);
 
 	dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels,
 				      sizeof(*dmac->channels), GFP_KERNEL);
@@ -1890,8 +1898,10 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 	INIT_LIST_HEAD(&engine->channels);
 
 	for (i = 0; i < dmac->n_channels; ++i) {
-		ret = rcar_dmac_chan_probe(dmac, &dmac->channels[i],
-					   i + channels_offset);
+		if (!(dmac->channels_mask & BIT(i)))
+			continue;
+
+		ret = rcar_dmac_chan_probe(dmac, &dmac->channels[i], i);
 		if (ret < 0)
 			goto error;
 	}
-- 
2.7.4

[PATCH v3 2/4] dmaengine: rcar-dmac: Use of_data values instead of a macro

[Yoshihiro Shimoda]

Since we will have changed memory mapping of the DMAC in the future,
this patch uses of_data values instead of a macro to calculate
each channel's base offset.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/dma/sh/rcar-dmac.c | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 3993ab6..74996a0 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -210,12 +210,20 @@ struct rcar_dmac {
 
 #define to_rcar_dmac(d)		container_of(d, struct rcar_dmac, engine)
 
+/*
+ * struct rcar_dmac_of_data - This driver's OF data
+ * @chan_offset_base: DMAC channels base offset
+ * @chan_offset_stride: DMAC channels offset stride
+ */
+struct rcar_dmac_of_data {
+	u32 chan_offset_base;
+	u32 chan_offset_stride;
+};
+
 /* -----------------------------------------------------------------------------
  * Registers
  */
 
-#define RCAR_DMAC_CHAN_OFFSET(i)	(0x8000 + 0x80 * (i))
-
 #define RCAR_DMAISTA			0x0020
 #define RCAR_DMASEC			0x0030
 #define RCAR_DMAOR			0x0060
@@ -1726,6 +1734,7 @@ static const struct dev_pm_ops rcar_dmac_pm = {
 
 static int rcar_dmac_chan_probe(struct rcar_dmac *dmac,
 				struct rcar_dmac_chan *rchan,
+				const struct rcar_dmac_of_data *data,
 				unsigned int index)
 {
 	struct platform_device *pdev = to_platform_device(dmac->dev);
@@ -1735,7 +1744,8 @@ static int rcar_dmac_chan_probe(struct rcar_dmac *dmac,
 	int ret;
 
 	rchan->index = index;
-	rchan->iomem = dmac->iomem + RCAR_DMAC_CHAN_OFFSET(index);
+	rchan->iomem = dmac->iomem + data->chan_offset_base +
+		       data->chan_offset_stride * index;
 	rchan->mid_rid = -EINVAL;
 
 	spin_lock_init(&rchan->lock);
@@ -1813,10 +1823,15 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 		DMA_SLAVE_BUSWIDTH_32_BYTES | DMA_SLAVE_BUSWIDTH_64_BYTES;
 	struct dma_device *engine;
 	struct rcar_dmac *dmac;
+	const struct rcar_dmac_of_data *data;
 	struct resource *mem;
 	unsigned int i;
 	int ret;
 
+	data = of_device_get_match_data(&pdev->dev);
+	if (!data)
+		return -EINVAL;
+
 	dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
 	if (!dmac)
 		return -ENOMEM;
@@ -1901,7 +1916,7 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 		if (!(dmac->channels_mask & BIT(i)))
 			continue;
 
-		ret = rcar_dmac_chan_probe(dmac, &dmac->channels[i], i);
+		ret = rcar_dmac_chan_probe(dmac, &dmac->channels[i], data, i);
 		if (ret < 0)
 			goto error;
 	}
@@ -1948,8 +1963,16 @@ static void rcar_dmac_shutdown(struct platform_device *pdev)
 	rcar_dmac_stop_all_chan(dmac);
 }
 
+static const struct rcar_dmac_of_data rcar_dmac_data = {
+	.chan_offset_base = 0x8000,
+	.chan_offset_stride = 0x80,
+};
+
 static const struct of_device_id rcar_dmac_of_ids[] = {
-	{ .compatible = "renesas,rcar-dmac", },
+	{
+		.compatible = "renesas,rcar-dmac",
+		.data = &rcar_dmac_data,
+	},
 	{ /* Sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, rcar_dmac_of_ids);
-- 
2.7.4

[PATCH v3 3/4] dmaengine: rcar-dmac: Use devm_platform_ioremap_resource()

[Yoshihiro Shimoda]

This patch uses devm_platform_ioremap_resource() instead of
using platform_get_resource() and devm_ioremap_resource() together
to simplify.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/dma/sh/rcar-dmac.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 74996a0..542786d 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -1824,7 +1824,6 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 	struct dma_device *engine;
 	struct rcar_dmac *dmac;
 	const struct rcar_dmac_of_data *data;
-	struct resource *mem;
 	unsigned int i;
 	int ret;
 
@@ -1863,8 +1862,7 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	/* Request resources. */
-	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	dmac->iomem = devm_ioremap_resource(&pdev->dev, mem);
+	dmac->iomem = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(dmac->iomem))
 		return PTR_ERR(dmac->iomem);
 
-- 
2.7.4

[PATCH v3 4/4] dmaengine: rcar-dmac: Add dma-channel-mask property support

[Yoshihiro Shimoda]

This patch adds dma-channel-mask property support not to reserve
some DMA channels for some reasons. (for example: a heterogeneous
CPU uses it.)

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/dma/sh/rcar-dmac.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 542786d..f06016d 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -203,7 +203,7 @@ struct rcar_dmac {
 
 	unsigned int n_channels;
 	struct rcar_dmac_chan *channels;
-	unsigned int channels_mask;
+	u32 channels_mask;
 
 	DECLARE_BITMAP(modules, 256);
 };
@@ -1810,7 +1810,15 @@ static int rcar_dmac_parse_of(struct device *dev, struct rcar_dmac *dmac)
 		return -EINVAL;
 	}
 
+	/*
+	 * If the driver is unable to read dma-channel-mask property,
+	 * the driver assumes that it can use all channels.
+	 */
 	dmac->channels_mask = GENMASK(dmac->n_channels - 1, 0);
+	of_property_read_u32(np, "dma-channel-mask", &dmac->channels_mask);
+
+	/* If the property has out-of-channel mask, this driver clears it */
+	dmac->channels_mask &= GENMASK(dmac->n_channels - 1, 0);
 
 	return 0;
 }
-- 
2.7.4

Re: [PATCH v3 3/4] dmaengine: rcar-dmac: Use devm_platform_ioremap_resource()

[Simon Horman]

On Mon, Sep 09, 2019 at 03:34:51PM +0900, Yoshihiro Shimoda wrote:
> This patch uses devm_platform_ioremap_resource() instead of
> using platform_get_resource() and devm_ioremap_resource() together
> to simplify.
> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Reviewed-by: Simon Horman <horms+renesas@verge.net.au>

> ---
>  drivers/dma/sh/rcar-dmac.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
> index 74996a0..542786d 100644
> --- a/drivers/dma/sh/rcar-dmac.c
> +++ b/drivers/dma/sh/rcar-dmac.c
> @@ -1824,7 +1824,6 @@ static int rcar_dmac_probe(struct platform_device *pdev)
>  	struct dma_device *engine;
>  	struct rcar_dmac *dmac;
>  	const struct rcar_dmac_of_data *data;
> -	struct resource *mem;
>  	unsigned int i;
>  	int ret;
>  
> @@ -1863,8 +1862,7 @@ static int rcar_dmac_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  
>  	/* Request resources. */
> -	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	dmac->iomem = devm_ioremap_resource(&pdev->dev, mem);
> +	dmac->iomem = devm_platform_ioremap_resource(pdev, 0);
>  	if (IS_ERR(dmac->iomem))
>  		return PTR_ERR(dmac->iomem);
>  
> -- 
> 2.7.4
> 

Re: [PATCH v3 2/4] dmaengine: rcar-dmac: Use of_data values instead of a macro

[Simon Horman]

On Mon, Sep 09, 2019 at 03:34:50PM +0900, Yoshihiro Shimoda wrote:
> Since we will have changed memory mapping of the DMAC in the future,
> this patch uses of_data values instead of a macro to calculate
> each channel's base offset.
> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Reviewed-by: Simon Horman <horms+renesas@verge.net.au>

Re: [PATCH v3 0/4] dmaengine: rcar-dmac: use of_data and add dma-channel-mask support

[Vinod Koul]

On 09-09-19, 15:34, Yoshihiro Shimoda wrote:
> This patch series is based on the latest slave-dma.git / next branch.
> 
> Changes from v2:
>  - Rebase the latest slave-dma.git / next branch (In other words,
>    this patch series doesn't depend any other branches.
>  - Cherry-picked a patch which is contained in v5.3-rc8 to solve any
>    dependency. (I'm not sure whether this is a right way or not...)
>   https://patchwork.kernel.org/project/linux-renesas-soc/list/?series=169317

Sorry for delay, I was on vacation + conference. Yeah ideally I would
merge fixes and this wouldn't be the case.

patch1 is no longer needed now, I have applied the rest

Thanks
-- 
~Vinod