diff mbox series

[v5,3/3] dmaengine: sf-pdma: Get number of channel by device tree

Message ID df6c8d1c701b33fa735dd072de3cb585dc60f2c9.1644215230.git.zong.li@sifive.com (mailing list archive)
State New, archived
Headers show
Series Determine the number of DMA channels by 'dma-channels' property | expand

Commit Message

Zong Li Feb. 7, 2022, 6:30 a.m. UTC
It currently assumes that there are always four channels, it would
cause the error if there is actually less than four channels. Change
that by getting number of channel from device tree.

For backwards-compatibility, it uses the default value (i.e. 4) when
there is no 'dma-channels' information in dts.

Signed-off-by: Zong Li <zong.li@sifive.com>
---
 drivers/dma/sf-pdma/sf-pdma.c | 21 ++++++++++++++-------
 drivers/dma/sf-pdma/sf-pdma.h |  8 ++------
 2 files changed, 16 insertions(+), 13 deletions(-)

Comments

Vinod Koul Feb. 15, 2022, 12:06 p.m. UTC | #1
On 07-02-22, 14:30, Zong Li wrote:
> It currently assumes that there are always four channels, it would
> cause the error if there is actually less than four channels. Change
> that by getting number of channel from device tree.
> 
> For backwards-compatibility, it uses the default value (i.e. 4) when
> there is no 'dma-channels' information in dts.
> 
> Signed-off-by: Zong Li <zong.li@sifive.com>
> ---
>  drivers/dma/sf-pdma/sf-pdma.c | 21 ++++++++++++++-------
>  drivers/dma/sf-pdma/sf-pdma.h |  8 ++------
>  2 files changed, 16 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c
> index f12606aeff87..2ae10b61dfa1 100644
> --- a/drivers/dma/sf-pdma/sf-pdma.c
> +++ b/drivers/dma/sf-pdma/sf-pdma.c
> @@ -482,9 +482,7 @@ static void sf_pdma_setup_chans(struct sf_pdma *pdma)
>  static int sf_pdma_probe(struct platform_device *pdev)
>  {
>  	struct sf_pdma *pdma;
> -	struct sf_pdma_chan *chan;
>  	struct resource *res;
> -	int len, chans;
>  	int ret;
>  	const enum dma_slave_buswidth widths =
>  		DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES |
> @@ -492,13 +490,21 @@ static int sf_pdma_probe(struct platform_device *pdev)
>  		DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES |
>  		DMA_SLAVE_BUSWIDTH_64_BYTES;
>  
> -	chans = PDMA_NR_CH;
> -	len = sizeof(*pdma) + sizeof(*chan) * chans;
> -	pdma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
> +	pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
>  	if (!pdma)
>  		return -ENOMEM;
>  
> -	pdma->n_chans = chans;
> +	ret = of_property_read_u32(pdev->dev.of_node, "dma-channels",
> +				   &pdma->n_chans);
> +	if (ret) {
> +		dev_notice(&pdev->dev, "set number of channels to default value: 4\n");

This is useful for only debug i think, so dev_dbg perhaps

> +		pdma->n_chans = PDMA_MAX_NR_CH;
> +	}
> +
> +	if (pdma->n_chans > PDMA_MAX_NR_CH) {
> +		dev_err(&pdev->dev, "the number of channels exceeds the maximum\n");
> +		return -EINVAL;
> +	}
>  
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	pdma->membase = devm_ioremap_resource(&pdev->dev, res);
> @@ -556,7 +562,7 @@ static int sf_pdma_remove(struct platform_device *pdev)
>  	struct sf_pdma_chan *ch;
>  	int i;
>  
> -	for (i = 0; i < PDMA_NR_CH; i++) {
> +	for (i = 0; i < pdma->n_chans; i++) {
>  		ch = &pdma->chans[i];
>  
>  		devm_free_irq(&pdev->dev, ch->txirq, ch);
> @@ -574,6 +580,7 @@ static int sf_pdma_remove(struct platform_device *pdev)
>  
>  static const struct of_device_id sf_pdma_dt_ids[] = {
>  	{ .compatible = "sifive,fu540-c000-pdma" },
> +	{ .compatible = "sifive,pdma0" },
>  	{},
>  };
>  MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids);
> diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h
> index 0c20167b097d..8127d792f639 100644
> --- a/drivers/dma/sf-pdma/sf-pdma.h
> +++ b/drivers/dma/sf-pdma/sf-pdma.h
> @@ -22,11 +22,7 @@
>  #include "../dmaengine.h"
>  #include "../virt-dma.h"
>  
> -#define PDMA_NR_CH					4
> -
> -#if (PDMA_NR_CH != 4)
> -#error "Please define PDMA_NR_CH to 4"
> -#endif
> +#define PDMA_MAX_NR_CH					4
>  
>  #define PDMA_BASE_ADDR					0x3000000
>  #define PDMA_CHAN_OFFSET				0x1000
> @@ -118,7 +114,7 @@ struct sf_pdma {
>  	void __iomem            *membase;
>  	void __iomem            *mappedbase;
>  	u32			n_chans;
> -	struct sf_pdma_chan	chans[PDMA_NR_CH];
> +	struct sf_pdma_chan	chans[PDMA_MAX_NR_CH];

why waste memory allocating max, we know number of channels in probe,
why not allocate runtime?
Zong Li Feb. 16, 2022, 6:52 a.m. UTC | #2
On Tue, Feb 15, 2022 at 8:06 PM Vinod Koul <vkoul@kernel.org> wrote:
>
> On 07-02-22, 14:30, Zong Li wrote:
> > It currently assumes that there are always four channels, it would
> > cause the error if there is actually less than four channels. Change
> > that by getting number of channel from device tree.
> >
> > For backwards-compatibility, it uses the default value (i.e. 4) when
> > there is no 'dma-channels' information in dts.
> >
> > Signed-off-by: Zong Li <zong.li@sifive.com>
> > ---
> >  drivers/dma/sf-pdma/sf-pdma.c | 21 ++++++++++++++-------
> >  drivers/dma/sf-pdma/sf-pdma.h |  8 ++------
> >  2 files changed, 16 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c
> > index f12606aeff87..2ae10b61dfa1 100644
> > --- a/drivers/dma/sf-pdma/sf-pdma.c
> > +++ b/drivers/dma/sf-pdma/sf-pdma.c
> > @@ -482,9 +482,7 @@ static void sf_pdma_setup_chans(struct sf_pdma *pdma)
> >  static int sf_pdma_probe(struct platform_device *pdev)
> >  {
> >       struct sf_pdma *pdma;
> > -     struct sf_pdma_chan *chan;
> >       struct resource *res;
> > -     int len, chans;
> >       int ret;
> >       const enum dma_slave_buswidth widths =
> >               DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES |
> > @@ -492,13 +490,21 @@ static int sf_pdma_probe(struct platform_device *pdev)
> >               DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES |
> >               DMA_SLAVE_BUSWIDTH_64_BYTES;
> >
> > -     chans = PDMA_NR_CH;
> > -     len = sizeof(*pdma) + sizeof(*chan) * chans;
> > -     pdma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
> > +     pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
> >       if (!pdma)
> >               return -ENOMEM;
> >
> > -     pdma->n_chans = chans;
> > +     ret = of_property_read_u32(pdev->dev.of_node, "dma-channels",
> > +                                &pdma->n_chans);
> > +     if (ret) {
> > +             dev_notice(&pdev->dev, "set number of channels to default value: 4\n");
>
> This is useful for only debug i think, so dev_dbg perhaps
>

Thanks for your suggestion, let me change it in the next version.

> > +             pdma->n_chans = PDMA_MAX_NR_CH;
> > +     }
> > +
> > +     if (pdma->n_chans > PDMA_MAX_NR_CH) {
> > +             dev_err(&pdev->dev, "the number of channels exceeds the maximum\n");
> > +             return -EINVAL;
> > +     }
> >
> >       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >       pdma->membase = devm_ioremap_resource(&pdev->dev, res);
> > @@ -556,7 +562,7 @@ static int sf_pdma_remove(struct platform_device *pdev)
> >       struct sf_pdma_chan *ch;
> >       int i;
> >
> > -     for (i = 0; i < PDMA_NR_CH; i++) {
> > +     for (i = 0; i < pdma->n_chans; i++) {
> >               ch = &pdma->chans[i];
> >
> >               devm_free_irq(&pdev->dev, ch->txirq, ch);
> > @@ -574,6 +580,7 @@ static int sf_pdma_remove(struct platform_device *pdev)
> >
> >  static const struct of_device_id sf_pdma_dt_ids[] = {
> >       { .compatible = "sifive,fu540-c000-pdma" },
> > +     { .compatible = "sifive,pdma0" },
> >       {},
> >  };
> >  MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids);
> > diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h
> > index 0c20167b097d..8127d792f639 100644
> > --- a/drivers/dma/sf-pdma/sf-pdma.h
> > +++ b/drivers/dma/sf-pdma/sf-pdma.h
> > @@ -22,11 +22,7 @@
> >  #include "../dmaengine.h"
> >  #include "../virt-dma.h"
> >
> > -#define PDMA_NR_CH                                   4
> > -
> > -#if (PDMA_NR_CH != 4)
> > -#error "Please define PDMA_NR_CH to 4"
> > -#endif
> > +#define PDMA_MAX_NR_CH                                       4
> >
> >  #define PDMA_BASE_ADDR                                       0x3000000
> >  #define PDMA_CHAN_OFFSET                             0x1000
> > @@ -118,7 +114,7 @@ struct sf_pdma {
> >       void __iomem            *membase;
> >       void __iomem            *mappedbase;
> >       u32                     n_chans;
> > -     struct sf_pdma_chan     chans[PDMA_NR_CH];
> > +     struct sf_pdma_chan     chans[PDMA_MAX_NR_CH];
>
> why waste memory allocating max, we know number of channels in probe,
> why not allocate runtime?
>

I kept it there because I'd like to do minimum change in this patch
set. You're right, let me change it in the next version.

> --
> ~Vinod
Palmer Dabbelt March 3, 2022, 8:43 p.m. UTC | #3
On Tue, 15 Feb 2022 22:52:14 PST (-0800), zong.li@sifive.com wrote:
> On Tue, Feb 15, 2022 at 8:06 PM Vinod Koul <vkoul@kernel.org> wrote:
>>
>> On 07-02-22, 14:30, Zong Li wrote:
>> > It currently assumes that there are always four channels, it would
>> > cause the error if there is actually less than four channels. Change
>> > that by getting number of channel from device tree.
>> >
>> > For backwards-compatibility, it uses the default value (i.e. 4) when
>> > there is no 'dma-channels' information in dts.
>> >
>> > Signed-off-by: Zong Li <zong.li@sifive.com>
>> > ---
>> >  drivers/dma/sf-pdma/sf-pdma.c | 21 ++++++++++++++-------
>> >  drivers/dma/sf-pdma/sf-pdma.h |  8 ++------
>> >  2 files changed, 16 insertions(+), 13 deletions(-)
>> >
>> > diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c
>> > index f12606aeff87..2ae10b61dfa1 100644
>> > --- a/drivers/dma/sf-pdma/sf-pdma.c
>> > +++ b/drivers/dma/sf-pdma/sf-pdma.c
>> > @@ -482,9 +482,7 @@ static void sf_pdma_setup_chans(struct sf_pdma *pdma)
>> >  static int sf_pdma_probe(struct platform_device *pdev)
>> >  {
>> >       struct sf_pdma *pdma;
>> > -     struct sf_pdma_chan *chan;
>> >       struct resource *res;
>> > -     int len, chans;
>> >       int ret;
>> >       const enum dma_slave_buswidth widths =
>> >               DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES |
>> > @@ -492,13 +490,21 @@ static int sf_pdma_probe(struct platform_device *pdev)
>> >               DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES |
>> >               DMA_SLAVE_BUSWIDTH_64_BYTES;
>> >
>> > -     chans = PDMA_NR_CH;
>> > -     len = sizeof(*pdma) + sizeof(*chan) * chans;
>> > -     pdma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
>> > +     pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
>> >       if (!pdma)
>> >               return -ENOMEM;
>> >
>> > -     pdma->n_chans = chans;
>> > +     ret = of_property_read_u32(pdev->dev.of_node, "dma-channels",
>> > +                                &pdma->n_chans);
>> > +     if (ret) {
>> > +             dev_notice(&pdev->dev, "set number of channels to default value: 4\n");
>>
>> This is useful for only debug i think, so dev_dbg perhaps
>>
>
> Thanks for your suggestion, let me change it in the next version.

Not sure if I'm missing something, but I don't see a v6.  I'm going to 
assume that one will be sent, but the suggested changes look minor 
enough so 

Acked-by: Palmer Dabbelt <palmer@rivosinc.com>

LMK if you guys were expecting this to go in via the RISC-V tree, 
otherwise I'll assume this aimed at the dmaengine tree.  Probably best to keep
all three together, so feel free to take the DTS updates as well -- having some
shared tag never hurts, but the DTs don't move that much so any conflicts
should be straight-forward to just fix at merge time.

Thanks!

>> > +             pdma->n_chans = PDMA_MAX_NR_CH;
>> > +     }
>> > +
>> > +     if (pdma->n_chans > PDMA_MAX_NR_CH) {
>> > +             dev_err(&pdev->dev, "the number of channels exceeds the maximum\n");
>> > +             return -EINVAL;
>> > +     }
>> >
>> >       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> >       pdma->membase = devm_ioremap_resource(&pdev->dev, res);
>> > @@ -556,7 +562,7 @@ static int sf_pdma_remove(struct platform_device *pdev)
>> >       struct sf_pdma_chan *ch;
>> >       int i;
>> >
>> > -     for (i = 0; i < PDMA_NR_CH; i++) {
>> > +     for (i = 0; i < pdma->n_chans; i++) {
>> >               ch = &pdma->chans[i];
>> >
>> >               devm_free_irq(&pdev->dev, ch->txirq, ch);
>> > @@ -574,6 +580,7 @@ static int sf_pdma_remove(struct platform_device *pdev)
>> >
>> >  static const struct of_device_id sf_pdma_dt_ids[] = {
>> >       { .compatible = "sifive,fu540-c000-pdma" },
>> > +     { .compatible = "sifive,pdma0" },
>> >       {},
>> >  };
>> >  MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids);
>> > diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h
>> > index 0c20167b097d..8127d792f639 100644
>> > --- a/drivers/dma/sf-pdma/sf-pdma.h
>> > +++ b/drivers/dma/sf-pdma/sf-pdma.h
>> > @@ -22,11 +22,7 @@
>> >  #include "../dmaengine.h"
>> >  #include "../virt-dma.h"
>> >
>> > -#define PDMA_NR_CH                                   4
>> > -
>> > -#if (PDMA_NR_CH != 4)
>> > -#error "Please define PDMA_NR_CH to 4"
>> > -#endif
>> > +#define PDMA_MAX_NR_CH                                       4
>> >
>> >  #define PDMA_BASE_ADDR                                       0x3000000
>> >  #define PDMA_CHAN_OFFSET                             0x1000
>> > @@ -118,7 +114,7 @@ struct sf_pdma {
>> >       void __iomem            *membase;
>> >       void __iomem            *mappedbase;
>> >       u32                     n_chans;
>> > -     struct sf_pdma_chan     chans[PDMA_NR_CH];
>> > +     struct sf_pdma_chan     chans[PDMA_MAX_NR_CH];
>>
>> why waste memory allocating max, we know number of channels in probe,
>> why not allocate runtime?
>>
>
> I kept it there because I'd like to do minimum change in this patch
> set. You're right, let me change it in the next version.
>
>> --
>> ~Vinod
Zong Li March 4, 2022, 8:52 a.m. UTC | #4
On Fri, Mar 4, 2022 at 4:43 AM Palmer Dabbelt <palmer@dabbelt.com> wrote:
>
> On Tue, 15 Feb 2022 22:52:14 PST (-0800), zong.li@sifive.com wrote:
> > On Tue, Feb 15, 2022 at 8:06 PM Vinod Koul <vkoul@kernel.org> wrote:
> >>
> >> On 07-02-22, 14:30, Zong Li wrote:
> >> > It currently assumes that there are always four channels, it would
> >> > cause the error if there is actually less than four channels. Change
> >> > that by getting number of channel from device tree.
> >> >
> >> > For backwards-compatibility, it uses the default value (i.e. 4) when
> >> > there is no 'dma-channels' information in dts.
> >> >
> >> > Signed-off-by: Zong Li <zong.li@sifive.com>
> >> > ---
> >> >  drivers/dma/sf-pdma/sf-pdma.c | 21 ++++++++++++++-------
> >> >  drivers/dma/sf-pdma/sf-pdma.h |  8 ++------
> >> >  2 files changed, 16 insertions(+), 13 deletions(-)
> >> >
> >> > diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c
> >> > index f12606aeff87..2ae10b61dfa1 100644
> >> > --- a/drivers/dma/sf-pdma/sf-pdma.c
> >> > +++ b/drivers/dma/sf-pdma/sf-pdma.c
> >> > @@ -482,9 +482,7 @@ static void sf_pdma_setup_chans(struct sf_pdma *pdma)
> >> >  static int sf_pdma_probe(struct platform_device *pdev)
> >> >  {
> >> >       struct sf_pdma *pdma;
> >> > -     struct sf_pdma_chan *chan;
> >> >       struct resource *res;
> >> > -     int len, chans;
> >> >       int ret;
> >> >       const enum dma_slave_buswidth widths =
> >> >               DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES |
> >> > @@ -492,13 +490,21 @@ static int sf_pdma_probe(struct platform_device *pdev)
> >> >               DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES |
> >> >               DMA_SLAVE_BUSWIDTH_64_BYTES;
> >> >
> >> > -     chans = PDMA_NR_CH;
> >> > -     len = sizeof(*pdma) + sizeof(*chan) * chans;
> >> > -     pdma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
> >> > +     pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
> >> >       if (!pdma)
> >> >               return -ENOMEM;
> >> >
> >> > -     pdma->n_chans = chans;
> >> > +     ret = of_property_read_u32(pdev->dev.of_node, "dma-channels",
> >> > +                                &pdma->n_chans);
> >> > +     if (ret) {
> >> > +             dev_notice(&pdev->dev, "set number of channels to default value: 4\n");
> >>
> >> This is useful for only debug i think, so dev_dbg perhaps
> >>
> >
> > Thanks for your suggestion, let me change it in the next version.
>
> Not sure if I'm missing something, but I don't see a v6.  I'm going to
> assume that one will be sent, but the suggested changes look minor
> enough so
>

I have been sending the v6 patchset, thank you for the review.

> Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
>
> LMK if you guys were expecting this to go in via the RISC-V tree,
> otherwise I'll assume this aimed at the dmaengine tree.  Probably best to keep
> all three together, so feel free to take the DTS updates as well -- having some
> shared tag never hurts, but the DTs don't move that much so any conflicts
> should be straight-forward to just fix at merge time.
>

Yes, if the v6 version is good enough and you could pick them into
RISC-V tree, I'd appreciate that. Thanks!

> Thanks!
>
> >> > +             pdma->n_chans = PDMA_MAX_NR_CH;
> >> > +     }
> >> > +
> >> > +     if (pdma->n_chans > PDMA_MAX_NR_CH) {
> >> > +             dev_err(&pdev->dev, "the number of channels exceeds the maximum\n");
> >> > +             return -EINVAL;
> >> > +     }
> >> >
> >> >       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> >       pdma->membase = devm_ioremap_resource(&pdev->dev, res);
> >> > @@ -556,7 +562,7 @@ static int sf_pdma_remove(struct platform_device *pdev)
> >> >       struct sf_pdma_chan *ch;
> >> >       int i;
> >> >
> >> > -     for (i = 0; i < PDMA_NR_CH; i++) {
> >> > +     for (i = 0; i < pdma->n_chans; i++) {
> >> >               ch = &pdma->chans[i];
> >> >
> >> >               devm_free_irq(&pdev->dev, ch->txirq, ch);
> >> > @@ -574,6 +580,7 @@ static int sf_pdma_remove(struct platform_device *pdev)
> >> >
> >> >  static const struct of_device_id sf_pdma_dt_ids[] = {
> >> >       { .compatible = "sifive,fu540-c000-pdma" },
> >> > +     { .compatible = "sifive,pdma0" },
> >> >       {},
> >> >  };
> >> >  MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids);
> >> > diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h
> >> > index 0c20167b097d..8127d792f639 100644
> >> > --- a/drivers/dma/sf-pdma/sf-pdma.h
> >> > +++ b/drivers/dma/sf-pdma/sf-pdma.h
> >> > @@ -22,11 +22,7 @@
> >> >  #include "../dmaengine.h"
> >> >  #include "../virt-dma.h"
> >> >
> >> > -#define PDMA_NR_CH                                   4
> >> > -
> >> > -#if (PDMA_NR_CH != 4)
> >> > -#error "Please define PDMA_NR_CH to 4"
> >> > -#endif
> >> > +#define PDMA_MAX_NR_CH                                       4
> >> >
> >> >  #define PDMA_BASE_ADDR                                       0x3000000
> >> >  #define PDMA_CHAN_OFFSET                             0x1000
> >> > @@ -118,7 +114,7 @@ struct sf_pdma {
> >> >       void __iomem            *membase;
> >> >       void __iomem            *mappedbase;
> >> >       u32                     n_chans;
> >> > -     struct sf_pdma_chan     chans[PDMA_NR_CH];
> >> > +     struct sf_pdma_chan     chans[PDMA_MAX_NR_CH];
> >>
> >> why waste memory allocating max, we know number of channels in probe,
> >> why not allocate runtime?
> >>
> >
> > I kept it there because I'd like to do minimum change in this patch
> > set. You're right, let me change it in the next version.
> >
> >> --
> >> ~Vinod
diff mbox series

Patch

diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c
index f12606aeff87..2ae10b61dfa1 100644
--- a/drivers/dma/sf-pdma/sf-pdma.c
+++ b/drivers/dma/sf-pdma/sf-pdma.c
@@ -482,9 +482,7 @@  static void sf_pdma_setup_chans(struct sf_pdma *pdma)
 static int sf_pdma_probe(struct platform_device *pdev)
 {
 	struct sf_pdma *pdma;
-	struct sf_pdma_chan *chan;
 	struct resource *res;
-	int len, chans;
 	int ret;
 	const enum dma_slave_buswidth widths =
 		DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES |
@@ -492,13 +490,21 @@  static int sf_pdma_probe(struct platform_device *pdev)
 		DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES |
 		DMA_SLAVE_BUSWIDTH_64_BYTES;
 
-	chans = PDMA_NR_CH;
-	len = sizeof(*pdma) + sizeof(*chan) * chans;
-	pdma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
+	pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
 	if (!pdma)
 		return -ENOMEM;
 
-	pdma->n_chans = chans;
+	ret = of_property_read_u32(pdev->dev.of_node, "dma-channels",
+				   &pdma->n_chans);
+	if (ret) {
+		dev_notice(&pdev->dev, "set number of channels to default value: 4\n");
+		pdma->n_chans = PDMA_MAX_NR_CH;
+	}
+
+	if (pdma->n_chans > PDMA_MAX_NR_CH) {
+		dev_err(&pdev->dev, "the number of channels exceeds the maximum\n");
+		return -EINVAL;
+	}
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	pdma->membase = devm_ioremap_resource(&pdev->dev, res);
@@ -556,7 +562,7 @@  static int sf_pdma_remove(struct platform_device *pdev)
 	struct sf_pdma_chan *ch;
 	int i;
 
-	for (i = 0; i < PDMA_NR_CH; i++) {
+	for (i = 0; i < pdma->n_chans; i++) {
 		ch = &pdma->chans[i];
 
 		devm_free_irq(&pdev->dev, ch->txirq, ch);
@@ -574,6 +580,7 @@  static int sf_pdma_remove(struct platform_device *pdev)
 
 static const struct of_device_id sf_pdma_dt_ids[] = {
 	{ .compatible = "sifive,fu540-c000-pdma" },
+	{ .compatible = "sifive,pdma0" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids);
diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h
index 0c20167b097d..8127d792f639 100644
--- a/drivers/dma/sf-pdma/sf-pdma.h
+++ b/drivers/dma/sf-pdma/sf-pdma.h
@@ -22,11 +22,7 @@ 
 #include "../dmaengine.h"
 #include "../virt-dma.h"
 
-#define PDMA_NR_CH					4
-
-#if (PDMA_NR_CH != 4)
-#error "Please define PDMA_NR_CH to 4"
-#endif
+#define PDMA_MAX_NR_CH					4
 
 #define PDMA_BASE_ADDR					0x3000000
 #define PDMA_CHAN_OFFSET				0x1000
@@ -118,7 +114,7 @@  struct sf_pdma {
 	void __iomem            *membase;
 	void __iomem            *mappedbase;
 	u32			n_chans;
-	struct sf_pdma_chan	chans[PDMA_NR_CH];
+	struct sf_pdma_chan	chans[PDMA_MAX_NR_CH];
 };
 
 #endif /* _SF_PDMA_H */