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Message-Id: <20210923085750.71968-1-zhang.lyra@gmail.com>
Date: Thu, 23 Sep 2021 16:57:50 +0800
From: Chunyan Zhang <zhang.lyra@...il.com>
To: Ulf Hansson <ulf.hansson@...aro.org>,
Adrian Hunter <adrian.hunter@...el.com>
Cc: linux-mmc@...r.kernel.org, Baolin Wang <baolin.wang7@...il.com>,
Orson Zhai <orsonzhai@...il.com>,
Chunyan Zhang <zhang.lyra@...il.com>,
Chunyan Zhang <chunyan.zhang@...soc.com>,
zhenxiong.lai@...soc.com, yuelin.tang@...soc.com,
LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH] mmc: sdhci-sprd: Wait until DLL locked after being configured
From: Zhenxiong Lai <zhenxiong.lai@...soc.com>
According to the specification, DLL status has to be locked before using it.
Signed-off-by: Zhenxiong Lai <zhenxiong.lai@...soc.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@...soc.com>
---
drivers/mmc/host/sdhci-sprd.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
index 11e375579cfb..83749c7a6db4 100644
--- a/drivers/mmc/host/sdhci-sprd.c
+++ b/drivers/mmc/host/sdhci-sprd.c
@@ -39,6 +39,9 @@
#define SDHCI_SPRD_BIT_POSRD_DLY_INV BIT(21)
#define SDHCI_SPRD_BIT_NEGRD_DLY_INV BIT(29)
+#define SDHCI_SPRD_REG_32_DLL_STS0 0x210
+#define SDHCI_SPRD_DLL_LOCKED BIT(18)
+
#define SDHCI_SPRD_REG_32_BUSY_POSI 0x250
#define SDHCI_SPRD_BIT_OUTR_CLK_AUTO_EN BIT(25)
#define SDHCI_SPRD_BIT_INNR_CLK_AUTO_EN BIT(24)
@@ -236,7 +239,7 @@ static inline void _sdhci_sprd_set_clock(struct sdhci_host *host,
static void sdhci_sprd_enable_phy_dll(struct sdhci_host *host)
{
- u32 tmp;
+ u32 tmp, timeout = 1000;
tmp = sdhci_readl(host, SDHCI_SPRD_REG_32_DLL_CFG);
tmp &= ~(SDHCI_SPRD_DLL_EN | SDHCI_SPRD_DLL_ALL_CPST_EN);
@@ -256,6 +259,21 @@ static void sdhci_sprd_enable_phy_dll(struct sdhci_host *host)
sdhci_writel(host, tmp, SDHCI_SPRD_REG_32_DLL_CFG);
/* wait 1ms */
usleep_range(1000, 1250);
+
+ while (--timeout) {
+ if ((sdhci_readl(host, SDHCI_SPRD_REG_32_DLL_STS0) &
+ SDHCI_SPRD_DLL_LOCKED))
+ break;
+ usleep_range(1000, 1250);
+ }
+
+ if (!timeout) {
+ pr_err("%s: DLL locked fail!\n", mmc_hostname(host->mmc));
+ pr_info("%s: DLL_STS0 : 0x%x, DLL_CFG : 0x%x\n",
+ mmc_hostname(host->mmc),
+ sdhci_readl(host, SDHCI_SPRD_REG_32_DLL_STS0),
+ sdhci_readl(host, SDHCI_SPRD_REG_32_DLL_CFG));
+ }
}
static void sdhci_sprd_set_clock(struct sdhci_host *host, unsigned int clock)
--
2.25.1
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