2021-09-23 09:02:56

by Chunyan Zhang

Subject: [PATCH] mmc: sdhci-sprd: Wait until DLL locked after being configured

From: Zhenxiong Lai <[email protected]>

According to the specification, DLL status has to be locked before using it.

Signed-off-by: Zhenxiong Lai <[email protected]>
Signed-off-by: Chunyan Zhang <[email protected]>
---
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

2021-09-24 17:05:15

by Adrian Hunter

Subject: Re: [PATCH] mmc: sdhci-sprd: Wait until DLL locked after being configured

On 23/09/21 11:57 am, Chunyan Zhang wrote:
> From: Zhenxiong Lai <[email protected]>
>
> According to the specification, DLL status has to be locked before using it.
>
> Signed-off-by: Zhenxiong Lai <[email protected]>
> Signed-off-by: Chunyan Zhang <[email protected]>
> ---
> 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) {

This could use read_poll_timeout() instead e.g.

if (read_poll_timeout(sdhci_readl, tmp, (tmp & SDHCI_SPRD_DLL_LOCKED),
2000, USEC_PER_SEC, false, host, SDHCI_SPRD_REG_32_DLL_STS0)) {




> + 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)
>