[PATCH 0/2] Add SDHCI support for APM X-Gene SoC using ARASAN SDHCI controller.

[PATCH 0/2] Add SDHCI support for APM X-Gene SoC using ARASAN SDHCI controller.

[Suman Tripathi]

Due to the fact that the existing of-arasan driver works with 32-bit platforms.
This patch tweaks existing of-arasan driver to work with 64-bit X-Gene
platform using IOMMU translation.

Signed-off-by: Suman Tripathi <stripathi@apm.com>
---

Suman Tripathi (2):
  mmc: host: arasan: Add addition of-arasan quirks and add IOMMU
    support.
  arm64: dts: Add  APM X-Gene SDHCI DTS node.

 arch/arm64/boot/dts/apm-storm.dtsi | 43 ++++++++++++++++++++++++++++++
 drivers/mmc/host/Kconfig           |  1 +
 drivers/mmc/host/sdhci-of-arasan.c | 54 ++++++++++++++++++++++++++++++++++++++
 drivers/mmc/host/sdhci-pltfm.c     | 12 +++++++++
 4 files changed, 110 insertions(+)

--
1.8.2.1

[PATCH 1/2] mmc: host: arasan: Add addition of-arasan quirks and add IOMMU support.

[Suman Tripathi]

Due to the fact that the existing of-arasan driver works with 32-bit platforms.
This patch tweaks existing of-arasan driver to work with 64-bit platform using
IOMMU translation.

In addition it adds support for more quirks and quirks2 obtained from device tree
inside the generic sdhci-platform(sdhci-pltfm.c) driver.

Signed-off-by: Suman Tripathi <stripathi@apm.com>
---
 drivers/mmc/host/Kconfig           |  1 +
 drivers/mmc/host/sdhci-of-arasan.c | 54 ++++++++++++++++++++++++++++++++++++++
 drivers/mmc/host/sdhci-pltfm.c     | 12 +++++++++
 3 files changed, 67 insertions(+)

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 4511358..0c6dc47 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -108,6 +108,7 @@ config MMC_SDHCI_OF_ARASAN
 	tristate "SDHCI OF support for the Arasan SDHCI controllers"
 	depends on MMC_SDHCI_PLTFM
 	depends on OF
+	select MMC_SDHCI_IO_ACCESSORS
 	help
 	  This selects the Arasan Secure Digital Host Controller Interface
 	  (SDHCI). This hardware is found e.g. in Xilinx' Zynq SoC.
diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index 5bd1092..c0e0c9b 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -20,6 +20,10 @@
  */

 #include <linux/module.h>
+#if defined(CONFIG_IOMMU_SUPPORT)
+#include <linux/amba/bus.h>
+#include <linux/iommu.h>
+#endif
 #include "sdhci-pltfm.h"

 #define SDHCI_ARASAN_CLK_CTRL_OFFSET	0x2c
@@ -34,8 +38,46 @@
  */
 struct sdhci_arasan_data {
 	struct clk	*clk_ahb;
+#if defined(CONFIG_IOMMU_SUPPORT)
+	struct iommu_domain *domain;
+#endif
 };

+static void sdhci_arasan_write_l(struct sdhci_host *host, u32 val, int reg)
+{
+#if defined(CONFIG_IOMMU_SUPPORT)
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
+	/*
+	 * This allows the arasan IP to integrate with 64-bit platform.
+	 * As the AHB dma masters generates 32-bit address so it needs
+	 * IO translation of 32-bit to 42-bit AXI address with help of IOMMU.
+	 */
+	if (reg == SDHCI_DMA_ADDRESS) {
+	        phys_addr_t dma_addr = sg_dma_address(host->data->sg);
+		sdhci_arasan->domain->ops->map(sdhci_arasan->domain, 0,
+					       dma_addr, 0, 0);
+	}
+#endif
+	writel(val, host->ioaddr + reg);
+}
+
+static  u32 xgene_sdhci_readl(struct sdhci_host *host, int reg)
+{
+#if defined(CONFIG_IOMMU_SUPPORT)
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
+
+	if (reg == SDHCI_INT_STATUS ) {
+		if ((readl(host->ioaddr + reg) & SDHCI_INT_DATA_MASK) ==
+		     SDHCI_INT_DMA_END)
+			sdhci_arasan->domain->ops->unmap(sdhci_arasan->domain,
+							 0, 0);
+	}
+#endif
+	return readl(host->ioaddr + reg);
+}
+
 static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
 {
 	u32 div;
@@ -58,6 +100,8 @@ static struct sdhci_ops sdhci_arasan_ops = {
 	.set_bus_width = sdhci_set_bus_width,
 	.reset = sdhci_reset,
 	.set_uhs_signaling = sdhci_set_uhs_signaling,
+	.write_l = sdhci_arasan_write_l,
+	.read_l = xgene_sdhci_readl,
 };

 static struct sdhci_pltfm_data sdhci_arasan_pdata = {
@@ -162,6 +206,16 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
 		goto clk_dis_ahb;
 	}

+#if defined(CONFIG_IOMMU_SUPPORT)
+	sdhci_arasan->domain = iommu_domain_alloc(&amba_bustype);
+	if (!sdhci_arasan->domain) {
+		dev_err(&pdev->dev, "Unable to allocate iommu domain\n");
+		return PTR_ERR(sdhci_arasan->domain);
+	}
+
+	iommu_attach_device(sdhci_arasan->domain, &pdev->dev);
+#endif
+
 	host = sdhci_pltfm_init(pdev, &sdhci_arasan_pdata, 0);
 	if (IS_ERR(host)) {
 		ret = PTR_ERR(host);
diff --git a/drivers/mmc/host/sdhci-pltfm.c b/drivers/mmc/host/sdhci-pltfm.c
index 7e834fb..08a97dc 100644
--- a/drivers/mmc/host/sdhci-pltfm.c
+++ b/drivers/mmc/host/sdhci-pltfm.c
@@ -90,6 +90,18 @@ void sdhci_get_of_property(struct platform_device *pdev)
 		if (of_get_property(np, "broken-cd", NULL))
 			host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;

+		if (of_get_property(np, "delay-after-power", NULL))
+			host->quirks |= SDHCI_QUIRK_DELAY_AFTER_POWER;
+
+		if (of_get_property(np, "no-hispd", NULL))
+			host->quirks |= SDHCI_QUIRK_NO_HISPD_BIT;
+
+		if (of_get_property(np, "broken-adma", NULL))
+			host->quirks |= SDHCI_QUIRK_BROKEN_ADMA;
+
+		if (of_get_property(np, "no-cmd23", NULL))
+			host->quirks2 |= SDHCI_QUIRK2_HOST_NO_CMD23;
+
 		if (of_get_property(np, "no-1-8-v", NULL))
 			host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V;

--
1.8.2.1

Re: [PATCH 1/2] mmc: host: arasan: Add addition of-arasan quirks and add IOMMU support.

[Arnd Bergmann]

On Monday 15 December 2014 22:31:06 Suman Tripathi wrote:
> @@ -162,6 +206,16 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>                 goto clk_dis_ahb;
>         }
> 
> +#if defined(CONFIG_IOMMU_SUPPORT)
> +       sdhci_arasan->domain = iommu_domain_alloc(&amba_bustype);
> +       if (!sdhci_arasan->domain) {
> +               dev_err(&pdev->dev, "Unable to allocate iommu domain\n");
> +               return PTR_ERR(sdhci_arasan->domain);
> +       }
> +
> +       iommu_attach_device(sdhci_arasan->domain, &pdev->dev);
> +#endif
> +
> 

Device drivers should never care about the implementation details
of the iommu. Please change the code to use the regular dma_map_*
interfaces that will work both with and without IOMMU.

	Arnd

Re: [PATCH 1/2] mmc: host: arasan: Add addition of-arasan quirks and add IOMMU support.

[Suman Tripathi]

Hi Arnd,

On Monday 15 December 2014 22:31:06 Suman Tripathi wrote:
> @@ -162,6 +206,16 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>                 goto clk_dis_ahb;
>         }
>
> +#if defined(CONFIG_IOMMU_SUPPORT)
> +       sdhci_arasan->domain = iommu_domain_alloc(&amba_bustype);
> +       if (!sdhci_arasan->domain) {
> +               dev_err(&pdev->dev, "Unable to allocate iommu domain\n");
> +               return PTR_ERR(sdhci_arasan->domain);
> +       }
> +
> +       iommu_attach_device(sdhci_arasan->domain, &pdev->dev);
> +#endif
> +
>

Device drivers should never care about the implementation details
of the iommu. Please change the code to use the regular dma_map_*
interfaces that will work both with and without IOMMU.

After refer to iommu binding , there is a service that allows "Remap
address space to allow devices to access physical memory ranges that
they otherwise wouldn't be capable of accessing." eg : 32-bit to 64
bit DMA .

So do we have any existing driver that uses this service ? Just asking
for suggestions.

On Tue, Dec 16, 2014 at 2:57 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Monday 15 December 2014 22:31:06 Suman Tripathi wrote:
>> @@ -162,6 +206,16 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>>                 goto clk_dis_ahb;
>>         }
>>
>> +#if defined(CONFIG_IOMMU_SUPPORT)
>> +       sdhci_arasan->domain = iommu_domain_alloc(&amba_bustype);
>> +       if (!sdhci_arasan->domain) {
>> +               dev_err(&pdev->dev, "Unable to allocate iommu domain\n");
>> +               return PTR_ERR(sdhci_arasan->domain);
>> +       }
>> +
>> +       iommu_attach_device(sdhci_arasan->domain, &pdev->dev);
>> +#endif
>> +
>>
>
> Device drivers should never care about the implementation details
> of the iommu. Please change the code to use the regular dma_map_*
> interfaces that will work both with and without IOMMU.
>
>         Arnd



-- 
Thanks,
with regards,
Suman Tripathi
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Re: [PATCH 1/2] mmc: host: arasan: Add addition of-arasan quirks and add IOMMU support.

[Arnd Bergmann]

On Tuesday 06 January 2015 17:10:29 Suman Tripathi wrote:
> Hi Arnd,
> > On Monday 15 December 2014 22:31:06 Suman Tripathi wrote:
> > > @@ -162,6 +206,16 @@ static int sdhci_arasan_probe(struct
> > > platform_device *pdev)> > > 
> > >                 goto clk_dis_ahb;
> > >         
> > >         }
> > > 
> > > +#if defined(CONFIG_IOMMU_SUPPORT)
> > > +       sdhci_arasan->domain = iommu_domain_alloc(&amba_bustype);
> > > +       if (!sdhci_arasan->domain) {
> > > +               dev_err(&pdev->dev, "Unable to allocate iommu
> > > domain\n");
> > > +               return PTR_ERR(sdhci_arasan->domain);
> > > +       }
> > > +
> > > +       iommu_attach_device(sdhci_arasan->domain, &pdev->dev);
> > > +#endif
> > > +
> > 
> > Device drivers should never care about the implementation details
> > of the iommu. Please change the code to use the regular dma_map_*
> > interfaces that will work both with and without IOMMU.
>
> After refer to iommu binding , there is a service that allows "Remap
> address space to allow devices to access physical memory ranges that
> they otherwise wouldn't be capable of accessing." eg : 32-bit to 64
> bit DMA .
> 
> So do we have any existing driver that uses this service ? Just asking
> for suggestions.

The interface is completely transparent to device drivers, it is
implemented as a separate 'struct dma_map_ops' that is normally
architecture independent, and that handles all sorts of DMA remapping
issues for the driver, including

- address space limits
- offsets between CPU and device addresses for the same memory
- cache flushes
- bus-level synchronization

On arm32, we currently support six sets of dma_map_ops including
two for IOMMU (coherent and noncoherent). On arm64, we currently
always use swiotlb, which solves your problem by copying memory to
bounce buffers. This is rather inefficient, and a new implementation
is being worked on, based on the arm32 implementation to support
IOMMUs in a generic way.

	Arnd

[PATCH 2/2] arm64: dts: Add APM X-Gene SDHCI DTS node.

[Suman Tripathi]

This patch adds the ahbclk and sdhciclk clock nodes and
the sdhci device tree nodes of APM X-Gene SDHCI controller.

Signed-off-by: Suman Tripathi <stripathi@apm.com>
---
 arch/arm64/boot/dts/apm-storm.dtsi | 43 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/arch/arm64/boot/dts/apm-storm.dtsi b/arch/arm64/boot/dts/apm-storm.dtsi
index c0aceef..18e291b 100644
--- a/arch/arm64/boot/dts/apm-storm.dtsi
+++ b/arch/arm64/boot/dts/apm-storm.dtsi
@@ -144,6 +144,40 @@
 				clock-output-names = "socplldiv2";
 			};

+			ahbclk: ahbclk@1f2ac000 {
+				compatible = "apm,xgene-device-clock";
+				#clock-cells = <1>;
+				clocks = <&socplldiv2 0>;
+				reg = <0x0 0x1f2ac000 0x0 0x1000
+					0x0 0x17000000 0x0 0x2000>;
+				reg-names = "csr-reg", "div-reg";
+				csr-offset = <0x0>;
+				csr-mask = <0x1>;
+				enable-offset = <0x8>;
+				enable-mask = <0x1>;
+				divider-offset = <0x164>;
+				divider-width = <0x5>;
+				divider-shift = <0x0>;
+				clock-output-names = "ahbclk";
+			};
+
+			sdioclk: sdioclk@1f2ac000 {
+				compatible = "apm,xgene-device-clock";
+				#clock-cells = <1>;
+				clocks = <&socplldiv2 0>;
+				reg = <0x0 0x1f2ac000 0x0 0x1000
+					0x0 0x17000000 0x0 0x2000>;
+				reg-names = "csr-reg", "div-reg";
+				csr-offset = <0x0>;
+				csr-mask = <0x2>;
+				enable-offset = <0x8>;
+				enable-mask = <0x2>;
+				divider-offset = <0x178>;
+				divider-width = <0x8>;
+				divider-shift = <0x0>;
+				clock-output-names = "sdioclk";
+			};
+
 			qmlclk: qmlclk {
 				compatible = "apm,xgene-device-clock";
 				#clock-cells = <1>;
@@ -397,6 +431,15 @@
 			clocks = <&rtcclk 0>;
 		};

+		sdhc0: sdhc@1c000000 {
+			device_type = "sdhc";
+			compatible = "arasan,sdhci-8.9a";
+			reg = <0x0 0x1c000000 0x0 0x100>;
+			interrupts = <0x0 0x49 0x4>;
+			clock-names = "clk_xin", "clk_ahb";
+			clocks = <&sdioclk 0>, <&ahbclk 0>;
+		};
+
 		menet: ethernet@17020000 {
 			compatible = "apm,xgene-enet";
 			status = "disabled";
--
1.8.2.1