Hello Martin,
On Wed, May 08, 2024 at 03:44:53PM +0200, Martin Kaiser wrote:
> Thus wrote Uwe Kleine-König (u.kleine-koenig@xxxxxxxxxxxxxx):
> > While in commit 2dd33f9cec90 ("spi: imx: support DMA for imx35") it was
> > claimed that DMA works on i.MX25, i.MX31 and i.MX35 the respective
> > device trees don't add DMA channels. The Reference manuals of i.MX31 and
> > i.MX25 also don't mention the CSPI core being DMA capable. (I didn't
> > check the others.)
>
> If I'm not mistaken, the imx25 reference manual
>
> https://www.nxp.com/docs/en/reference-manual/IMX25RM.pdf
>
> does say that CSPI has DMA support. Section 18.1.1 (Features) lists DMA as one
> of the features. There's also DMA events (section 3) for CSPI-1/2/3 RX, TX.
Oh indeed. I don't know what made me claim that DMA isn't mentioned in
the reference manual. Maybe I looked at the i2c chapter.
I now did:
diff --git a/arch/arm/boot/dts/nxp/imx/imx25.dtsi b/arch/arm/boot/dts/nxp/imx/imx25.dtsi
index 4a85684deff8..710b28a41bae 100644
--- a/arch/arm/boot/dts/nxp/imx/imx25.dtsi
+++ b/arch/arm/boot/dts/nxp/imx/imx25.dtsi
@@ -190,6 +190,8 @@ spi1: spi@43fa4000 {
reg = <0x43fa4000 0x4000>;
clocks = <&clks 78>, <&clks 78>;
clock-names = "ipg", "per";
+ dmas = <&sdma 8 1 0>, <&sdma 9 1 0>;
+ dma-names = "rx", "tx";
interrupts = <14>;
status = "disabled";
};
@@ -229,6 +231,8 @@ spi3: spi@50004000 {
interrupts = <0>;
clocks = <&clks 80>, <&clks 80>;
clock-names = "ipg", "per";
+ dmas = <&sdma 34 1 0>, <&sdma 35 1 0>;
+ dma-names = "rx", "tx";
status = "disabled";
};
@@ -257,6 +261,8 @@ spi2: spi@50010000 {
reg = <0x50010000 0x4000>;
clocks = <&clks 79>, <&clks 79>;
clock-names = "ipg", "per";
+ dmas = <&sdma 6 1 0>, <&sdma 7 1 0>;
+ dma-names = "rx", "tx";
interrupts = <13>;
status = "disabled";
};
And spi still works. I see an issue, but I think that's orthogonal to
adding DMA. Will send a formal patch when I debugged that.
Thanks for your feedback,
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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