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From patchwork Thu Jun 28 08:13:30 2018
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Content-Type: text/plain; charset="utf-8"
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Subject: [2/3] mmc: sdhci: add quirk to prevent higher speed modes
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From: Stefan Agner <stefan@agner.ch>
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X-Patchwork-Id: 10493273
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Message-Id: <20180628081331.13051-3-stefan@agner.ch>
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To: adrian.hunter@intel.com, ulf.hansson@linaro.org
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Cc: fabio.estevam@nxp.com, haibo.chen@nxp.com, aisheng.dong@nxp.com,
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 michael@amarulasolutions.com, rmk+kernel@armlinux.org.uk,
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 linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
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 Stefan Agner <stefan@agner.ch>
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Date: Thu, 28 Jun 2018 10:13:30 +0200
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Some hosts are capable of running higher speed modes but do not
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have the board support for it. Introduce a quirk which prevents
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the stack from using modes running at 100MHz or faster.
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Signed-off-by: Stefan Agner <stefan@agner.ch>
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---
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 drivers/mmc/host/sdhci.c | 8 ++++++++
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 drivers/mmc/host/sdhci.h | 2 ++
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 2 files changed, 10 insertions(+)
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diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
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index 1c828e0e9905..8ac257dfaab3 100644
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--- a/drivers/mmc/host/sdhci.c
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+++ b/drivers/mmc/host/sdhci.c
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@@ -3749,6 +3749,14 @@ int sdhci_setup_host(struct sdhci_host *host)
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 		}
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 	}
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+	if (host->quirks2 & SDHCI_QUIRK2_NO_UHS_HS200_HS400) {
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+		host->caps1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
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+				 SDHCI_SUPPORT_DDR50);
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+
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+		mmc->caps2 &= ~(MMC_CAP2_HSX00_1_8V | MMC_CAP2_HSX00_1_2V |
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+				MMC_CAP2_HS400_ES);
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+	}
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+
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 	if (host->quirks2 & SDHCI_QUIRK2_NO_1_8_V) {
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 		host->caps1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
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 				 SDHCI_SUPPORT_DDR50);
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diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
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index 23966f887da6..cb2433d6d61f 100644
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--- a/drivers/mmc/host/sdhci.h
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+++ b/drivers/mmc/host/sdhci.h
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@@ -450,6 +450,8 @@ struct sdhci_host {
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  * obtainable timeout.
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  */
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 #define SDHCI_QUIRK2_DISABLE_HW_TIMEOUT			(1<<17)
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+/* Do not support any higher speeds (>50MHz) */
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+#define SDHCI_QUIRK2_NO_UHS_HS200_HS400			(1<<18)
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 	int irq;		/* Device IRQ */
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 	void __iomem *ioaddr;	/* Mapped address */