* [PATCH 1/2] dt-bindings: mmc: ingenic: Support using bi-directional DMA channel
2021-12-20 19:08 [PATCH 0/2] mmc: ingenic: Support bi-directional DMA channel Paul Cercueil
@ 2021-12-20 19:08 ` Paul Cercueil
2021-12-20 19:08 ` [PATCH 2/2] mmc: jz4740: Support using a " Paul Cercueil
2021-12-21 13:03 ` [PATCH 0/2] mmc: ingenic: Support " Ulf Hansson
2 siblings, 0 replies; 4+ messages in thread
From: Paul Cercueil @ 2021-12-20 19:08 UTC (permalink / raw)
To: Ulf Hansson, Rob Herring
Cc: list, linux-mmc, devicetree, linux-kernel, linux-mips, Paul Cercueil
Update the binding documentation and the examples to support
bi-directional DMA channels.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
.../devicetree/bindings/mmc/ingenic,mmc.yaml | 37 ++++++++++++++++---
1 file changed, 31 insertions(+), 6 deletions(-)
diff --git a/Documentation/devicetree/bindings/mmc/ingenic,mmc.yaml b/Documentation/devicetree/bindings/mmc/ingenic,mmc.yaml
index 01d5c6da0eeb..2d10aedf2e00 100644
--- a/Documentation/devicetree/bindings/mmc/ingenic,mmc.yaml
+++ b/Documentation/devicetree/bindings/mmc/ingenic,mmc.yaml
@@ -39,14 +39,15 @@ properties:
const: mmc
dmas:
- items:
- - description: DMA controller phandle and request line for RX
- - description: DMA controller phandle and request line for TX
+ minItems: 1
+ maxItems: 2
dma-names:
- items:
- - const: rx
- - const: tx
+ oneOf:
+ - items:
+ - const: rx
+ - const: tx
+ - const: tx-rx
required:
- compatible
@@ -80,3 +81,27 @@ examples:
<&dma JZ4780_DMA_MSC0_TX 0xffffffff>;
dma-names = "rx", "tx";
};
+ - |
+ #include <dt-bindings/clock/ingenic,jz4780-cgu.h>
+ #include <dt-bindings/dma/jz4780-dma.h>
+ /*
+ * Alternative version of the example above,
+ * but using one single DMA channel for both
+ * TX and RX.
+ */
+ mmc1: mmc@13460000 {
+ compatible = "ingenic,jz4780-mmc";
+ reg = <0x13460000 0x1000>;
+
+ interrupt-parent = <&intc>;
+ interrupts = <36>;
+
+ clocks = <&cgu JZ4780_CLK_MSC1>;
+ clock-names = "mmc";
+
+ cap-sd-highspeed;
+ cap-mmc-highspeed;
+ cap-sdio-irq;
+ dmas = <&dma JZ4780_DMA_MSC1_TX JZ4780_DMA_MSC1_RX 0xffffffff>;
+ dma-names = "tx-rx";
+ };
--
2.34.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/2] mmc: jz4740: Support using a bi-directional DMA channel
2021-12-20 19:08 [PATCH 0/2] mmc: ingenic: Support bi-directional DMA channel Paul Cercueil
2021-12-20 19:08 ` [PATCH 1/2] dt-bindings: mmc: ingenic: Support using " Paul Cercueil
@ 2021-12-20 19:08 ` Paul Cercueil
2021-12-21 13:03 ` [PATCH 0/2] mmc: ingenic: Support " Ulf Hansson
2 siblings, 0 replies; 4+ messages in thread
From: Paul Cercueil @ 2021-12-20 19:08 UTC (permalink / raw)
To: Ulf Hansson, Rob Herring
Cc: list, linux-mmc, devicetree, linux-kernel, linux-mips, Paul Cercueil
Since the MMC/SD controller in Ingenic SoCs work in half-duplex, it is
possible to use one single DMA channel for both TX and RX operations,
instead of using separate channels.
As some older Ingenic SoCs offer only a handful of DMA channels,
supporting bi-directional channels allow more hardware to use the
channels that would otherwise be used for the MMC/SD operation.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
drivers/mmc/host/jz4740_mmc.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/jz4740_mmc.c b/drivers/mmc/host/jz4740_mmc.c
index 80a2c270d502..a0b94f61ddcf 100644
--- a/drivers/mmc/host/jz4740_mmc.c
+++ b/drivers/mmc/host/jz4740_mmc.c
@@ -217,11 +217,23 @@ static void jz4740_mmc_release_dma_channels(struct jz4740_mmc_host *host)
return;
dma_release_channel(host->dma_tx);
- dma_release_channel(host->dma_rx);
+ if (host->dma_rx)
+ dma_release_channel(host->dma_rx);
}
static int jz4740_mmc_acquire_dma_channels(struct jz4740_mmc_host *host)
{
+ struct device *dev = mmc_dev(host->mmc);
+
+ host->dma_tx = dma_request_chan(dev, "tx-rx");
+ if (!IS_ERR(host->dma_tx))
+ return 0;
+
+ if (PTR_ERR(host->dma_tx) != -ENODEV) {
+ dev_err(dev, "Failed to get dma tx-rx channel\n");
+ return PTR_ERR(host->dma_tx);
+ }
+
host->dma_tx = dma_request_chan(mmc_dev(host->mmc), "tx");
if (IS_ERR(host->dma_tx)) {
dev_err(mmc_dev(host->mmc), "Failed to get dma_tx channel\n");
@@ -241,7 +253,10 @@ static int jz4740_mmc_acquire_dma_channels(struct jz4740_mmc_host *host)
static inline struct dma_chan *jz4740_mmc_get_dma_chan(struct jz4740_mmc_host *host,
struct mmc_data *data)
{
- return (data->flags & MMC_DATA_READ) ? host->dma_rx : host->dma_tx;
+ if ((data->flags & MMC_DATA_READ) && host->dma_rx)
+ return host->dma_rx;
+ else
+ return host->dma_tx;
}
static void jz4740_mmc_dma_unmap(struct jz4740_mmc_host *host,
--
2.34.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH 0/2] mmc: ingenic: Support bi-directional DMA channel
2021-12-20 19:08 [PATCH 0/2] mmc: ingenic: Support bi-directional DMA channel Paul Cercueil
2021-12-20 19:08 ` [PATCH 1/2] dt-bindings: mmc: ingenic: Support using " Paul Cercueil
2021-12-20 19:08 ` [PATCH 2/2] mmc: jz4740: Support using a " Paul Cercueil
@ 2021-12-21 13:03 ` Ulf Hansson
2 siblings, 0 replies; 4+ messages in thread
From: Ulf Hansson @ 2021-12-21 13:03 UTC (permalink / raw)
To: Paul Cercueil
Cc: Rob Herring, list, linux-mmc, devicetree, linux-kernel, linux-mips
On Mon, 20 Dec 2021 at 20:08, Paul Cercueil <paul@crapouillou.net> wrote:
>
> Hi Ulf,
>
> This patchset adds support for using a single DMA channel for both RX
> and TX operations, instead of using separate DMA channels for each
> operation.
>
> As some older Ingenic SoCs offer only a handful of DMA channels,
> supporting bi-directional channels allow more hardware to use the
> channels that would otherwise be used for the MMC/SD operation.
>
> Note that the Device Tree binding for the DMA controller has been
> updated in a (already merged) patchset, so that it accepts a 3 cells
> (#dma-cells == 3) instead of just 2. It was merged in the DMA tree, so I
> am not sure the autobuilders will like this YAML - but it was checked
> without errors.
>
> I also removed the descriptions of the "dmas" property in the YAML, as
> they really weren't adding anything and were getting in my way.
>
> There are patches touching the driver file merged in the PM tree (the
> ones that use the new PM macros) but I expect no problem here, they
> touch different parts of the file.
>
> Cheers,
> -Paul
>
> Paul Cercueil (2):
> dt-bindings: mmc: ingenic: Support using bi-directional DMA channel
> mmc: jz4740: Support using a bi-directional DMA channel
>
> .../devicetree/bindings/mmc/ingenic,mmc.yaml | 37 ++++++++++++++++---
> drivers/mmc/host/jz4740_mmc.c | 19 +++++++++-
> 2 files changed, 48 insertions(+), 8 deletions(-)
>
Applied for next, thanks!
Let's see how this goes when the changes hit linux-next. I will have
to drop them, if we encounter any problems.
Kind regards
Uffe
^ permalink raw reply [flat|nested] 4+ messages in thread