From 3f23df72dc351e9ffe5eb577fcc38876dacba305 Mon Sep 17 00:00:00 2001 From: Zach Brown Date: Mon, 28 Nov 2016 13:16:39 -0600 Subject: [PATCH] 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 Reviewed-by: Jaeden Amero Reviewed-by: Josh Cartwright Signed-off-by: Zach Brown Acked-by: Adrian Hunter Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci-pci-core.c | 32 +++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c index e6010f4dd9a8..1a72d32af07f 100644 --- a/drivers/mmc/host/sdhci-pci-core.c +++ b/drivers/mmc/host/sdhci-pci-core.c @@ -27,6 +27,7 @@ #include #include #include +#include #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; -- 2.20.1