[PATCH 2/3] mmc: sdhci: add quirk to prevent higher speed modes

Stefan Agner
2018-06-28T08:13:30Z

Some hosts are capable of running higher speed modes but do not
have the board support for it. Introduce a quirk which prevents
the stack from using modes running at 100MHz or faster.

Signed-off-by: Stefan Agner <stefan@agner.ch>
---
drivers/mmc/host/sdhci.c | 8 ++++++++
drivers/mmc/host/sdhci.h | 2 ++
2 files changed, 10 insertions(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 1c828e0e9905..8ac257dfaab3 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3749,6 +3749,14 @@ int sdhci_setup_host(struct sdhci_host *host)
}
}

+ if (host->quirks2 & SDHCI_QUIRK2_NO_UHS_HS200_HS400) {
+ host->caps1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
+ SDHCI_SUPPORT_DDR50);
+
+ mmc->caps2 &= ~(MMC_CAP2_HSX00_1_8V | MMC_CAP2_HSX00_1_2V |
+ MMC_CAP2_HS400_ES);
+ }
+
if (host->quirks2 & SDHCI_QUIRK2_NO_1_8_V) {
host->caps1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
SDHCI_SUPPORT_DDR50);
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 23966f887da6..cb2433d6d61f 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -450,6 +450,8 @@ struct sdhci_host {
* obtainable timeout.
*/
#define SDHCI_QUIRK2_DISABLE_HW_TIMEOUT (1<<17)
+/* Do not support any higher speeds (>50MHz) */
+#define SDHCI_QUIRK2_NO_UHS_HS200_HS400 (1<<18)

int irq; /* Device IRQ */
void __iomem *ioaddr; /* Mapped address */
--
2.18.0