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authorElad Nachman <enachman@marvell.com>2024-02-22 22:09:30 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-03-06 14:45:11 +0000
commit4974d928d5e3909bd8cfe4b0bca2509636a8ebf2 (patch)
tree03514271b9022c09cdb1a4dfd0f6af2d87727f57
parentc65c475560851291ad64272d4b85b55e70c4adbb (diff)
downloadlinux-4974d928d5e3909bd8cfe4b0bca2509636a8ebf2.tar.gz
mmc: sdhci-xenon: fix PHY init clock stability
commit 8e9f25a290ae0016353c9ea13314c95fb3207812 upstream. Each time SD/mmc phy is initialized, at times, in some of the attempts, phy fails to completes its initialization which results into timeout error. Per the HW spec, it is a pre-requisite to ensure a stable SD clock before a phy initialization is attempted. Fixes: 06c8b667ff5b ("mmc: sdhci-xenon: Add support to PHYs of Marvell Xenon SDHC") Acked-by: Adrian Hunter <adrian.hunter@intel.com> Cc: stable@vger.kernel.org Signed-off-by: Elad Nachman <enachman@marvell.com> Link: https://lore.kernel.org/r/20240222200930.1277665-1-enachman@marvell.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/mmc/host/sdhci-xenon-phy.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-xenon-phy.c b/drivers/mmc/host/sdhci-xenon-phy.c
index 52a8e1217124a..cc9d28b75eb91 100644
--- a/drivers/mmc/host/sdhci-xenon-phy.c
+++ b/drivers/mmc/host/sdhci-xenon-phy.c
@@ -11,6 +11,7 @@
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/ktime.h>
+#include <linux/iopoll.h>
#include <linux/of_address.h>
#include "sdhci-pltfm.h"
@@ -218,6 +219,19 @@ static int xenon_alloc_emmc_phy(struct sdhci_host *host)
return 0;
}
+static int xenon_check_stability_internal_clk(struct sdhci_host *host)
+{
+ u32 reg;
+ int err;
+
+ err = read_poll_timeout(sdhci_readw, reg, reg & SDHCI_CLOCK_INT_STABLE,
+ 1100, 20000, false, host, SDHCI_CLOCK_CONTROL);
+ if (err)
+ dev_err(mmc_dev(host->mmc), "phy_init: Internal clock never stabilized.\n");
+
+ return err;
+}
+
/*
* eMMC 5.0/5.1 PHY init/re-init.
* eMMC PHY init should be executed after:
@@ -234,6 +248,11 @@ static int xenon_emmc_phy_init(struct sdhci_host *host)
struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
struct xenon_emmc_phy_regs *phy_regs = priv->emmc_phy_regs;
+ int ret = xenon_check_stability_internal_clk(host);
+
+ if (ret)
+ return ret;
+
reg = sdhci_readl(host, phy_regs->timing_adj);
reg |= XENON_PHY_INITIALIZAION;
sdhci_writel(host, reg, phy_regs->timing_adj);