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mmc: sdhci-xenon: fix PHY init clock stability

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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: 06c8b667ff ("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>
This commit is contained in:
Elad Nachman 2024-02-22 22:09:30 +02:00 committed by Greg Kroah-Hartman
parent d3c703c22b
commit 36b02df0a6
1 changed files with 19 additions and 0 deletions
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19
drivers/mmc/host/sdhci-xenon-phy.c
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@ -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);