summaryrefslogtreecommitdiffstats
path: root/drivers/mmc
diff options
context:
space:
mode:
authorZach Brown <zach.brown@ni.com>2016-11-28 13:16:39 -0600
committerUlf Hansson <ulf.hansson@linaro.org>2016-12-05 10:31:19 +0100
commit3f23df72dc351e9ffe5eb577fcc38876dacba305 (patch)
tree15e8c19ff44db0c2cb2acb2ea84ce66bd59e376a /drivers/mmc
parent42b06496407c03f4c89e19c5b9d4973446d2f1af (diff)
downloadop-kernel-dev-3f23df72dc351e9ffe5eb577fcc38876dacba305.zip
op-kernel-dev-3f23df72dc351e9ffe5eb577fcc38876dacba305.tar.gz
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: 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> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/sdhci-pci-core.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index e6010f4..1a72d32 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"
@@ -375,8 +376,39 @@ static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot)
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)
{
+ int err;
+
+ err = ni_set_max_freq(slot);
+ if (err)
+ return err;
+
slot->host->mmc->caps |= MMC_CAP_POWER_OFF_CARD | MMC_CAP_NONREMOVABLE |
MMC_CAP_WAIT_WHILE_BUSY;
return 0;
OpenPOWER on IntegriCloud