From: Angus Ainslie <angus@akkea.ca>
To: Lucas Stach <l.stach@pengutronix.de>
Cc: linux-kernel@vger.kernel.org, Vinod Koul <vkoul@kernel.org>,
NXP Linux Team <linux-imx@nxp.com>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 2/3] dma: imx-sdma: add clock ratio 1:1 check
Date: Mon, 21 Jan 2019 07:43:26 -0700 [thread overview]
Message-ID: <141a054976519d22aa195affca633c21@www.akkea.ca> (raw)
In-Reply-To: <1548062262.2465.5.camel@pengutronix.de>
Hi Lucas,
On 2019-01-21 02:17, Lucas Stach wrote:
> Hi Angus,
>
> Am Samstag, den 19.01.2019, 19:31 -0700 schrieb Angus Ainslie (Purism):
>> On i.mx8 mscale B0 chip, AHB/SDMA clock ratio 2:1 can't be supportted,
>> since SDMA clock ratio has to be increased to 250Mhz, AHB can't reach
>> to 500Mhz, so use 1:1 instead.
>>
>> based on NXP commit MLK-16841-1
>>
>> > Signed-off-by: Angus Ainslie (Purism) <angus@akkea.ca>
>> ---
>> .../devicetree/bindings/dma/fsl-imx-sdma.txt | 1 +
>> drivers/dma/imx-sdma.c | 20
>> +++++++++++++++----
>> 2 files changed, 17 insertions(+), 4 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
>> b/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
>> index 3c9a57a8443b..17544c1820b7 100644
>> --- a/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
>> +++ b/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
>> @@ -67,6 +67,7 @@ Optional properties:
>> reg is the GPR register offset.
>> shift is the bit position inside the GPR register.
>> val is the value of the bit (0 or 1).
>> +- fsl,ratio-1-1: AHB/SDMA core clock ration 1:1, 2:1 without this.
>
> Why does this need a separate DT property? Shouldn't the driver be able
> to infer this from the clock rates going into the SDMA hardware?
>
That's probably a better way to do it then setting the property can't
get missed. I'll address it in v3.
Angus
> Regards,
> Lucas
>
>> Examples:
>>
>> diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
>> index 0b3a67ff8e82..65dada21d3c1 100644
>> --- a/drivers/dma/imx-sdma.c
>> +++ b/drivers/dma/imx-sdma.c
>> @@ -440,6 +440,8 @@ struct sdma_engine {
>> > > unsigned int irq;
>> > > dma_addr_t bd0_phys;
>> > > struct sdma_buffer_descriptor *bd0;
>> > + /* clock ratio for AHB:SDMA core. 1:1 is 1, 2:1 is 0*/
>> > > + bool clk_ratio;
>> };
>>
>> static int sdma_config_write(struct dma_chan *chan,
>> @@ -662,8 +664,14 @@ static int sdma_run_channel0(struct sdma_engine
>> *sdma)
>> > dev_err(sdma->dev, "Timeout waiting for CH0 ready\n");
>>
>> > /* Set bits of CONFIG register with dynamic context switching */
>> > - if (readl(sdma->regs + SDMA_H_CONFIG) == 0)
>> > - writel_relaxed(SDMA_H_CONFIG_CSM, sdma->regs + SDMA_H_CONFIG);
>> > + if (readl(sdma->regs + SDMA_H_CONFIG) == 0) {
>> > + if (sdma->clk_ratio)
>> > + reg = SDMA_H_CONFIG_CSM | SDMA_H_CONFIG_ACR;
>> > + else
>> > + reg = SDMA_H_CONFIG_CSM;
>> +
>> > + writel_relaxed(reg, sdma->regs + SDMA_H_CONFIG);
>> > + }
>>
>> > return ret;
>> }
>> @@ -1880,8 +1888,10 @@ static int sdma_init(struct sdma_engine *sdma)
>> > writel_relaxed(0x4050, sdma->regs + SDMA_CHN0ADDR);
>>
>> > /* Set bits of CONFIG register but with static context switching */
>> > - /* FIXME: Check whether to set ACR bit depending on clock ratios */
>> > - writel_relaxed(0, sdma->regs + SDMA_H_CONFIG);
>> > + if (sdma->clk_ratio)
>> > + writel_relaxed(SDMA_H_CONFIG_ACR, sdma->regs + SDMA_H_CONFIG);
>> > + else
>> > + writel_relaxed(0, sdma->regs + SDMA_H_CONFIG);
>>
>> > writel_relaxed(ccb_phys, sdma->regs + SDMA_H_C0PTR);
>>
>> @@ -1975,6 +1985,8 @@ static int sdma_probe(struct platform_device
>> *pdev)
>> > if (!sdma)
>> > return -ENOMEM;
>>
>> > + sdma->clk_ratio = of_property_read_bool(np, "fsl,ratio-1-1");
>> +
>> > spin_lock_init(&sdma->channel_0_lock);
>>
>> > sdma->dev = &pdev->dev;
next prev parent reply other threads:[~2019-01-21 14:43 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-20 2:31 [PATCH v2 0/3] dma: imx-sdma: add the sdma engine to the imx8mq Angus Ainslie (Purism)
2019-01-20 2:31 ` [PATCH v2 1/3] dma: imx-sdma: fix NULL pointer de-reference Angus Ainslie (Purism)
2019-01-20 9:54 ` Daniel Baluta
2019-01-20 15:04 ` Angus Ainslie
2019-01-20 2:31 ` [PATCH v2 2/3] dma: imx-sdma: add clock ratio 1:1 check Angus Ainslie (Purism)
2019-01-20 9:58 ` Daniel Baluta
2019-01-20 14:38 ` Angus Ainslie
2019-01-20 18:00 ` Daniel Baluta
2019-01-21 9:17 ` Lucas Stach
2019-01-21 14:43 ` Angus Ainslie [this message]
2019-01-20 2:31 ` [PATCH v2 3/3] imx8mq.dtsi: add the sdma nodes Angus Ainslie (Purism)
2019-01-23 15:23 ` [PATCH v3 0/5] dma: imx-sdma: add the sdma engine to the imx8mq Angus Ainslie (Purism)
2019-01-23 15:23 ` [PATCH v3 1/5] dma: imx-sdma: add clock ratio 1:1 check Angus Ainslie (Purism)
2019-01-23 15:43 ` Lucas Stach
2019-01-23 15:23 ` [PATCH v3 2/5] dma: imx-sdma: add imx8mq sdma compatible parts Angus Ainslie (Purism)
2019-01-23 15:23 ` [PATCH v3 3/5] dt-bindings: dma: fsl-imx-sdma: add imx8mq compatible string Angus Ainslie (Purism)
2019-01-23 15:23 ` [PATCH v3 4/5] dma: imx-sdma: add an index for imx8mq multi sdma devices Angus Ainslie (Purism)
2019-01-23 15:31 ` Lucas Stach
2019-01-23 15:42 ` Angus Ainslie
2019-01-23 15:55 ` Vinod Koul
2019-01-23 15:23 ` [PATCH v3 5/5] imx8mq.dtsi: add the sdma nodes Angus Ainslie (Purism)
2019-01-23 16:50 ` Lucas Stach
2019-01-25 2:55 ` [PATCH v4 0/5] dmaengine: imx-sdma: add the sdma engine to the imx8mq Angus Ainslie (Purism)
2019-01-25 2:55 ` [PATCH v4 1/5] dmaengine: imx-sdma: add clock ratio 1:1 check Angus Ainslie (Purism)
2019-01-25 9:42 ` Lucas Stach
2019-01-25 2:55 ` [PATCH v4 2/5] dmaengine: imx-sdma: add imx8mq sdma compatible parts Angus Ainslie (Purism)
2019-01-25 9:35 ` Lucas Stach
2019-01-25 2:55 ` [PATCH v4 3/5] dt-bindings: dma: fsl-imx-sdma: add fsl,imx8mq to the accepted compatible node Angus Ainslie (Purism)
2019-01-25 9:39 ` Lucas Stach
2019-01-25 2:55 ` [PATCH v4 4/5] dma: imx-sdma: add a test for imx8mq multi sdma devices Angus Ainslie (Purism)
2019-01-25 9:34 ` Lucas Stach
2019-01-25 2:55 ` [PATCH v4 5/5] imx8mq.dtsi: add the sdma nodes Angus Ainslie (Purism)
2019-01-25 9:38 ` Lucas Stach
2019-01-28 6:08 ` [PATCH v5 0/5] dmaengine: imx-sdma: add the sdma engine to the imx8mq Angus Ainslie (Purism)
2019-01-28 6:08 ` [PATCH v5 1/5] dmaengine: imx-sdma: add clock ratio 1:1 check Angus Ainslie (Purism)
2019-01-28 9:29 ` Lucas Stach
2019-01-28 6:08 ` [PATCH v5 2/5] dmaengine: imx-sdma: add imx8mq sdma compatible parts Angus Ainslie (Purism)
2019-01-28 9:32 ` Lucas Stach
2019-01-28 6:08 ` [PATCH v5 3/5] dt-bindings: dma: fsl-imx-sdma: add fsl,imx8mq to the accepted compatible node Angus Ainslie (Purism)
2019-01-28 6:08 ` [PATCH v5 4/5] dmaengine: imx-sdma: add a test for imx8mq multi sdma devices Angus Ainslie (Purism)
2019-01-28 9:33 ` Lucas Stach
2019-01-28 6:08 ` [PATCH v5 5/5] dmaengine: imx-sdma: fix consistent dma test failures Angus Ainslie (Purism)
2019-01-28 16:03 ` [PATCH v6 0/3] dmaengine: imx-sdma: add the sdma engine to the imx8mq Angus Ainslie (Purism)
2019-01-28 16:03 ` [PATCH v6 1/3] dmaengine: imx-sdma: add clock ratio 1:1 check Angus Ainslie (Purism)
2019-01-28 16:03 ` [PATCH v6 2/3] dmaengine: imx-sdma: add a test for imx8mq multi sdma devices Angus Ainslie (Purism)
2019-02-25 13:31 ` Daniel Baluta
2019-01-28 16:03 ` [PATCH v6 3/3] dmaengine: imx-sdma: fix consistent dma test failures Angus Ainslie (Purism)
2019-02-25 17:56 ` [PATCH v6 0/3] dmaengine: imx-sdma: add the sdma engine to the imx8mq Vinod Koul
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