[RFC v2 0/2] mmc: sdhci-pci: Use ACPI to set max frequency of sdio host controller

[RFC v2 0/2] mmc: sdhci-pci: Use ACPI to set max frequency of sdio host controller

[Zach Brown]

On some boards, max SDIO frequency is limited by trace lengths and other layout
choices. We would like a way to specify this limitation so the driver can
behave accordingly.

This patch set assumes that the limitation has been reported in an ACPI table
which the driver can check to get the max frequency.

The first patch creates a PCI ID and support for the Intel byt sdio where NI is
the subvendor.

The second patch uses the ACPI table to set f_max during the new
ni_byt_sdio_probe_slot.

v2:
  * Use acpi_evaluate_integer() instead of
    acpi_get_handle()/acpi_evaluate_object()


Zach Brown (2):
  mmc: sdhci-pci: Add PCI ID for Intel byt sdio host controller
    sub-vended by NI
  mmc: sdhci-pci: Use ACPI to get max frequency for Intel byt sdio    
    controller sub-vended by NI

 drivers/mmc/host/sdhci-pci-core.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

-- 
2.7.4

[RFC v2 1/2] mmc: sdhci-pci: Add PCI ID for Intel byt sdio host controller sub-vended by NI

[Zach Brown]

Add PCI ID for Intel byt sdio host controller sub-vended by NI.

The controller has different behavior because of the board layout NI
puts it on.

Signed-off-by: Zach Brown <zach.brown@ni.com>
---
 drivers/mmc/host/sdhci-pci-core.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index 1d9e00a..9741505 100644
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -375,6 +375,13 @@ static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot)
 	return 0;
 }
 
+static int ni_byt_sdio_probe_slot(struct sdhci_pci_slot *slot)
+{
+	slot->host->mmc->caps |= MMC_CAP_POWER_OFF_CARD | MMC_CAP_NONREMOVABLE |
+				 MMC_CAP_WAIT_WHILE_BUSY;
+	return 0;
+}
+
 static int byt_sdio_probe_slot(struct sdhci_pci_slot *slot)
 {
 	slot->host->mmc->caps |= MMC_CAP_POWER_OFF_CARD | MMC_CAP_NONREMOVABLE |
@@ -447,6 +454,15 @@ static const struct sdhci_pci_fixes sdhci_intel_byt_emmc = {
 	.ops		= &sdhci_intel_byt_ops,
 };
 
+static const struct sdhci_pci_fixes sdhci_ni_byt_sdio = {
+	.quirks		= SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
+	.quirks2	= SDHCI_QUIRK2_HOST_OFF_CARD_ON |
+			  SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
+	.allow_runtime_pm = true,
+	.probe_slot	= ni_byt_sdio_probe_slot,
+	.ops		= &sdhci_intel_byt_ops,
+};
+
 static const struct sdhci_pci_fixes sdhci_intel_byt_sdio = {
 	.quirks		= SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
 	.quirks2	= SDHCI_QUIRK2_HOST_OFF_CARD_ON |
@@ -1079,6 +1095,14 @@ static const struct pci_device_id pci_ids[] = {
 	{
 		.vendor		= PCI_VENDOR_ID_INTEL,
 		.device		= PCI_DEVICE_ID_INTEL_BYT_SDIO,
+		.subvendor	= PCI_VENDOR_ID_NI,
+		.subdevice	= 0x7884,
+		.driver_data	= (kernel_ulong_t)&sdhci_ni_byt_sdio,
+	},
+
+	{
+		.vendor		= PCI_VENDOR_ID_INTEL,
+		.device		= PCI_DEVICE_ID_INTEL_BYT_SDIO,
 		.subvendor	= PCI_ANY_ID,
 		.subdevice	= PCI_ANY_ID,
 		.driver_data	= (kernel_ulong_t)&sdhci_intel_byt_sdio,
-- 
2.7.4

[RFC v2 2/2] mmc: sdhci-pci: Use ACPI to get max frequency for Intel byt sdio controller sub-vended by NI

[Zach Brown]

On NI 9037 boards the max SDIO frequency is limited by trace lengths
and other layout choices. The max SDIO frequency is stored in an ACPI
table.

The driver reads the ACPI entry MXFQ during sdio_probe_slot and sets the
f_max field of the host.

Signed-off-by: Nathan Sullivan <nathan.sullivan@ni.com>
Reviewed-by: Jaeden Amero <jaeden.amero@ni.com>
Reviewed-by: Josh Cartwright <joshc@ni.com>
Signed-off-by: Zach Brown <zach.brown@ni.com>
---
 drivers/mmc/host/sdhci-pci-core.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index 9741505..4c31d16 100644
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -27,6 +27,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/mmc/slot-gpio.h>
 #include <linux/mmc/sdhci-pci-data.h>
+#include <linux/acpi.h>
 
 #include "sdhci.h"
 #include "sdhci-pci.h"
@@ -377,6 +378,18 @@ static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot)
 
 static int ni_byt_sdio_probe_slot(struct sdhci_pci_slot *slot)
 {
+#ifdef CONFIG_ACPI
+	/* Get max freq from ACPI for NI hardware */
+	acpi_status status;
+	unsigned long long max_freq;
+
+	status = acpi_evaluate_integer(ACPI_HANDLE(&slot->chip->pdev->dev),
+				       "MXFQ", NULL, &max_freq);
+	if (ACPI_FAILURE(status))
+		return -EINVAL;
+
+	slot->host->mmc->f_max = max_freq * 1000000;
+#endif
 	slot->host->mmc->caps |= MMC_CAP_POWER_OFF_CARD | MMC_CAP_NONREMOVABLE |
 				 MMC_CAP_WAIT_WHILE_BUSY;
 	return 0;
-- 
2.7.4

Re: [RFC v2 2/2] mmc: sdhci-pci: Use ACPI to get max frequency for Intel byt sdio controller sub-vended by NI

[Adrian Hunter]

On 15/11/16 18:32, Zach Brown wrote:
> On NI 9037 boards the max SDIO frequency is limited by trace lengths
> and other layout choices. The max SDIO frequency is stored in an ACPI
> table.
> 
> The driver reads the ACPI entry MXFQ during sdio_probe_slot and sets the
> f_max field of the host.
> 
> Signed-off-by: Nathan Sullivan <nathan.sullivan@ni.com>
> Reviewed-by: Jaeden Amero <jaeden.amero@ni.com>
> Reviewed-by: Josh Cartwright <joshc@ni.com>
> Signed-off-by: Zach Brown <zach.brown@ni.com>
> ---
>  drivers/mmc/host/sdhci-pci-core.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
> index 9741505..4c31d16 100644
> --- a/drivers/mmc/host/sdhci-pci-core.c
> +++ b/drivers/mmc/host/sdhci-pci-core.c
> @@ -27,6 +27,7 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/mmc/slot-gpio.h>
>  #include <linux/mmc/sdhci-pci-data.h>
> +#include <linux/acpi.h>
>  
>  #include "sdhci.h"
>  #include "sdhci-pci.h"
> @@ -377,6 +378,18 @@ static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot)
>  
>  static int ni_byt_sdio_probe_slot(struct sdhci_pci_slot *slot)
>  {
> +#ifdef CONFIG_ACPI
> +	/* Get max freq from ACPI for NI hardware */

The comment seems a little redundant.

> +	acpi_status status;
> +	unsigned long long max_freq;
> +
> +	status = acpi_evaluate_integer(ACPI_HANDLE(&slot->chip->pdev->dev),
> +				       "MXFQ", NULL, &max_freq);
> +	if (ACPI_FAILURE(status))
> +		return -EINVAL;

I wonder if you should print an error message to let the user know why the
driver failed to probe.

> +
> +	slot->host->mmc->f_max = max_freq * 1000000;
> +#endif
>  	slot->host->mmc->caps |= MMC_CAP_POWER_OFF_CARD | MMC_CAP_NONREMOVABLE |
>  				 MMC_CAP_WAIT_WHILE_BUSY;
>  	return 0;
>