Commit 3f23df72 authored by Zach Brown's avatar Zach Brown Committed by Ulf Hansson

mmc: sdhci-pci: Use ACPI to get max frequency for Intel NI byt sdio

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: default avatarNathan Sullivan <nathan.sullivan@ni.com>
Reviewed-by: default avatarJaeden Amero <jaeden.amero@ni.com>
Reviewed-by: default avatarJosh Cartwright <joshc@ni.com>
Signed-off-by: default avatarZach Brown <zach.brown@ni.com>
Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 42b06496
...@@ -27,6 +27,7 @@ ...@@ -27,6 +27,7 @@
#include <linux/pm_runtime.h> #include <linux/pm_runtime.h>
#include <linux/mmc/slot-gpio.h> #include <linux/mmc/slot-gpio.h>
#include <linux/mmc/sdhci-pci-data.h> #include <linux/mmc/sdhci-pci-data.h>
#include <linux/acpi.h>
#include "sdhci.h" #include "sdhci.h"
#include "sdhci-pci.h" #include "sdhci-pci.h"
...@@ -375,8 +376,39 @@ static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot) ...@@ -375,8 +376,39 @@ static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot)
return 0; return 0;
} }
#ifdef CONFIG_ACPI
static int ni_set_max_freq(struct sdhci_pci_slot *slot)
{
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)) {
dev_err(&slot->chip->pdev->dev,
"MXFQ not found in acpi table\n");
return -EINVAL;
}
slot->host->mmc->f_max = max_freq * 1000000;
return 0;
}
#else
static inline int ni_set_max_freq(struct sdhci_pci_slot *slot)
{
return 0;
}
#endif
static int ni_byt_sdio_probe_slot(struct sdhci_pci_slot *slot) static int ni_byt_sdio_probe_slot(struct sdhci_pci_slot *slot)
{ {
int err;
err = ni_set_max_freq(slot);
if (err)
return err;
slot->host->mmc->caps |= MMC_CAP_POWER_OFF_CARD | MMC_CAP_NONREMOVABLE | slot->host->mmc->caps |= MMC_CAP_POWER_OFF_CARD | MMC_CAP_NONREMOVABLE |
MMC_CAP_WAIT_WHILE_BUSY; MMC_CAP_WAIT_WHILE_BUSY;
return 0; return 0;
......
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