Re: [PATCH] BLACKFIN MEDIA DRIVER: rewrite the blackfin style of read/write into common style

From: Steven Miao
Date: Tue Jan 20 2015 - 04:42:32 EST

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In reply to: Hans Verkuil: "Re: [PATCH] BLACKFIN MEDIA DRIVER: rewrite the blackfin style of read/write into common style"
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Hi Hans,

On Mon, Jan 19, 2015 at 5:45 PM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
> On 01/19/2015 04:13 AM, Hao Liang wrote:
>> Hi Hans,
>>
>> Thank you for your reply.
>> This change comes largely from a non-blackfin architecture dsp processor of ADI want to reuse this driver.
>> And i have tested common read/write function on blackfin board to ensure usability and stability.
>
> Well, looking at arch/blackfin/include/asm/def_LPBlackfin.h it seems that for certain
> blackfin variants the bfin_read/write functions insert an extra nop, so unless you
> test on one of those variants you wouldn't see any problems relating to this change
> (and possibly not even then if this is a rare race condition).
>
> You will have to check this with the blackfin architecture maintainer, Steven Miao
> (added to the CC list). Without the OK of someone who actually understands that
> architecture and the 'ANOMALY_05000198' issues I am not going to merge this.
the ANOMALY_05000198 only exists in blackfin bf533 and bf561 old
silicon revision, and this ppi driver mostly will be used on bf609 and
later platform.
>
> If the bfin_read/write functions are really needed for the blackfin architecture,
we will sync the __raw_read/write macros with bfin_read/write, and
test it on most of the blackfin bf5xx and bf6xx platform.
> then you can always make ppi_read/write functions that check the architecture and use
> bfin_read/write if it is a blackfin and readw/writew otherwise.
>
> That should be safe.
>
> Regards,
>
> Hans
>
>>
>> BR
>> Hao
>>
>> 2015-01-16 19:34 GMT+08:00 Hans Verkuil <hverkuil@xxxxxxxxx <mailto:hverkuil@xxxxxxxxx>>:
>>
>> Hi Hao,
>>
>> Why would you do this? read/writew() is AFAICT not the same as bfin_read/write16
>> (defined in arch/blackfin/include/asm/def_LPBlackfin.h). And all other blackfin
>> sources I've seen all use bfin_read/write.
>>
>> So unless there is a good reason for this change I am not going to accept this.
>>
>> Regards,
>>
>> Hans
>>
>> On 01/14/2015 07:57 AM, Hao Liang wrote:
>> > Signed-off-by: Hao Liang <hliang1025@xxxxxxxxx <mailto:hliang1025@xxxxxxxxx>>
>> > ---
>> > drivers/media/platform/blackfin/ppi.c | 72 ++++++++++++++++-----------------
>> > 1 file changed, 35 insertions(+), 37 deletions(-)
>> >
>> > diff --git a/drivers/media/platform/blackfin/ppi.c b/drivers/media/platform/blackfin/ppi.c
>> > index cff63e5..de4b5c7 100644
>> > --- a/drivers/media/platform/blackfin/ppi.c
>> > +++ b/drivers/media/platform/blackfin/ppi.c
>> > @@ -20,6 +20,7 @@
>> > #include <linux/module.h>
>> > #include <linux/slab.h>
>> > #include <linux/platform_device.h>
>> > +#include <linux/io.h>
>> >
>> > #include <asm/bfin_ppi.h>
>> > #include <asm/blackfin.h>
>> > @@ -59,10 +60,10 @@ static irqreturn_t ppi_irq_err(int irq, void *dev_id)
>> > /* register on bf561 is cleared when read
>> > * others are W1C
>> > */
>> > - status = bfin_read16(&reg->status);
>> > + status = readw(&reg->status);
>> > if (status & 0x3000)
>> > ppi->err = true;
>> > - bfin_write16(&reg->status, 0xff00);
>> > + writew(0xff00, &reg->status);
>> > break;
>> > }
>> > case PPI_TYPE_EPPI:
>> > @@ -70,10 +71,10 @@ static irqreturn_t ppi_irq_err(int irq, void *dev_id)
>> > struct bfin_eppi_regs *reg = info->base;
>> > unsigned short status;
>> >
>> > - status = bfin_read16(&reg->status);
>> > + status = readw(&reg->status);
>> > if (status & 0x2)
>> > ppi->err = true;
>> > - bfin_write16(&reg->status, 0xffff);
>> > + writew(0xffff, &reg->status);
>> > break;
>> > }
>> > case PPI_TYPE_EPPI3:
>> > @@ -81,10 +82,10 @@ static irqreturn_t ppi_irq_err(int irq, void *dev_id)
>> > struct bfin_eppi3_regs *reg = info->base;
>> > unsigned long stat;
>> >
>> > - stat = bfin_read32(&reg->stat);
>> > + stat = readl(&reg->stat);
>> > if (stat & 0x2)
>> > ppi->err = true;
>> > - bfin_write32(&reg->stat, 0xc0ff);
>> > + writel(0xc0ff, &reg->stat);
>> > break;
>> > }
>> > default:
>> > @@ -139,26 +140,25 @@ static int ppi_start(struct ppi_if *ppi)
>> > case PPI_TYPE_PPI:
>> > {
>> > struct bfin_ppi_regs *reg = info->base;
>> > - bfin_write16(&reg->control, ppi->ppi_control);
>> > + writew(ppi->ppi_control, &reg->control);
>> > break;
>> > }
>> > case PPI_TYPE_EPPI:
>> > {
>> > struct bfin_eppi_regs *reg = info->base;
>> > - bfin_write32(&reg->control, ppi->ppi_control);
>> > + writel(ppi->ppi_control, &reg->control);
>> > break;
>> > }
>> > case PPI_TYPE_EPPI3:
>> > {
>> > struct bfin_eppi3_regs *reg = info->base;
>> > - bfin_write32(&reg->ctl, ppi->ppi_control);
>> > + writel(ppi->ppi_control, &reg->ctl);
>> > break;
>> > }
>> > default:
>> > return -EINVAL;
>> > }
>> >
>> > - SSYNC();
>> > return 0;
>> > }
>> >
>> > @@ -172,19 +172,19 @@ static int ppi_stop(struct ppi_if *ppi)
>> > case PPI_TYPE_PPI:
>> > {
>> > struct bfin_ppi_regs *reg = info->base;
>> > - bfin_write16(&reg->control, ppi->ppi_control);
>> > + writew(ppi->ppi_control, &reg->control);
>> > break;
>> > }
>> > case PPI_TYPE_EPPI:
>> > {
>> > struct bfin_eppi_regs *reg = info->base;
>> > - bfin_write32(&reg->control, ppi->ppi_control);
>> > + writel(ppi->ppi_control, &reg->control);
>> > break;
>> > }
>> > case PPI_TYPE_EPPI3:
>> > {
>> > struct bfin_eppi3_regs *reg = info->base;
>> > - bfin_write32(&reg->ctl, ppi->ppi_control);
>> > + writel(ppi->ppi_control, &reg->ctl);
>> > break;
>> > }
>> > default:
>> > @@ -195,7 +195,6 @@ static int ppi_stop(struct ppi_if *ppi)
>> > clear_dma_irqstat(info->dma_ch);
>> > disable_dma(info->dma_ch);
>> >
>> > - SSYNC();
>> > return 0;
>> > }
>> >
>> > @@ -242,9 +241,9 @@ static int ppi_set_params(struct ppi_if *ppi, struct ppi_params *params)
>> > if (params->ppi_control & DMA32)
>> > dma32 = 1;
>> >
>> > - bfin_write16(&reg->control, ppi->ppi_control);
>> > - bfin_write16(&reg->count, samples_per_line - 1);
>> > - bfin_write16(&reg->frame, params->frame);
>> > + writew(ppi->ppi_control, &reg->control);
>> > + writew(samples_per_line - 1, &reg->count);
>> > + writew(params->frame, &reg->frame);
>> > break;
>> > }
>> > case PPI_TYPE_EPPI:
>> > @@ -255,13 +254,13 @@ static int ppi_set_params(struct ppi_if *ppi, struct ppi_params *params)
>> > || (params->ppi_control & 0x38000) > DLEN_16)
>> > dma32 = 1;
>> >
>> > - bfin_write32(&reg->control, ppi->ppi_control);
>> > - bfin_write16(&reg->line, samples_per_line);
>> > - bfin_write16(&reg->frame, params->frame);
>> > - bfin_write16(&reg->hdelay, hdelay);
>> > - bfin_write16(&reg->vdelay, params->vdelay);
>> > - bfin_write16(&reg->hcount, hcount);
>> > - bfin_write16(&reg->vcount, params->height);
>> > + writel(ppi->ppi_control, &reg->control);
>> > + writew(samples_per_line, &reg->line);
>> > + writew(params->frame, &reg->frame);
>> > + writew(hdelay, &reg->hdelay);
>> > + writew(params->vdelay, &reg->vdelay);
>> > + writew(hcount, &reg->hcount);
>> > + writew(params->height, &reg->vcount);
>> > break;
>> > }
>> > case PPI_TYPE_EPPI3:
>> > @@ -272,15 +271,15 @@ static int ppi_set_params(struct ppi_if *ppi, struct ppi_params *params)
>> > || (params->ppi_control & 0x70000) > DLEN_16)
>> > dma32 = 1;
>> >
>> > - bfin_write32(&reg->ctl, ppi->ppi_control);
>> > - bfin_write32(&reg->line, samples_per_line);
>> > - bfin_write32(&reg->frame, params->frame);
>> > - bfin_write32(&reg->hdly, hdelay);
>> > - bfin_write32(&reg->vdly, params->vdelay);
>> > - bfin_write32(&reg->hcnt, hcount);
>> > - bfin_write32(&reg->vcnt, params->height);
>> > + writel(ppi->ppi_control, &reg->ctl);
>> > + writel(samples_per_line, &reg->line);
>> > + writel(params->frame, &reg->frame);
>> > + writel(hdelay, &reg->hdly);
>> > + writel(params->vdelay, &reg->vdly);
>> > + writel(hcount, &reg->hcnt);
>> > + writel(params->height, &reg->vcnt);
>> > if (params->int_mask)
>> > - bfin_write32(&reg->imsk, params->int_mask & 0xFF);
>> > + writel(params->int_mask & 0xFF, &reg->imsk);
>> > if (ppi->ppi_control & PORT_DIR) {
>> > u32 hsync_width, vsync_width, vsync_period;
>> >
>> > @@ -288,10 +287,10 @@ static int ppi_set_params(struct ppi_if *ppi, struct ppi_params *params)
>> > * params->bpp / params->dlen;
>> > vsync_width = params->vsync * samples_per_line;
>> > vsync_period = samples_per_line * params->frame;
>> > - bfin_write32(&reg->fs1_wlhb, hsync_width);
>> > - bfin_write32(&reg->fs1_paspl, samples_per_line);
>> > - bfin_write32(&reg->fs2_wlvb, vsync_width);
>> > - bfin_write32(&reg->fs2_palpf, vsync_period);
>> > + writel(hsync_width, &reg->fs1_wlhb);
>> > + writel(samples_per_line, &reg->fs1_paspl);
>> > + writel(vsync_width, &reg->fs2_wlvb);
>> > + writel(vsync_period, &reg->fs2_palpf);
>> > }
>> > break;
>> > }
>> > @@ -313,7 +312,6 @@ static int ppi_set_params(struct ppi_if *ppi, struct ppi_params *params)
>> > set_dma_y_count(info->dma_ch, params->height);
>> > set_dma_config(info->dma_ch, dma_config);
>> >
>> > - SSYNC();
>> > return 0;
>> > }
>> >
>> >
>>
>>
>
-steven
--
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Next message: Vitaly Kuznetsov: "Re: [PATCH v2 1/3] Drivers: hv: check vmbus_device_create() return value in vmbus_process_offer()"
Previous message: Krzysztof Kozlowski: "Bisected BUG: using smp_processor_id() in preemptible"
In reply to: Hans Verkuil: "Re: [PATCH] BLACKFIN MEDIA DRIVER: rewrite the blackfin style of read/write into common style"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]