diff mbox series

[01/10] mmc: tegra: Poll for calibration completion

Message ID 1532442591-5640-2-git-send-email-avienamo@nvidia.com
State New
Headers show
Series Update the pad autocal procedure | expand

Commit Message

Aapo Vienamo July 24, 2018, 2:29 p.m. UTC
Implement polling with 10 ms timeout for automatic pad drive strength
calibration.

Signed-off-by: Aapo Vienamo <avienamo@nvidia.com>
---
 drivers/mmc/host/sdhci-tegra.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

Comments

Mikko Perttunen July 25, 2018, 7:04 a.m. UTC | #1
On 24.07.2018 17:29, Aapo Vienamo wrote:
> Implement polling with 10 ms timeout for automatic pad drive strength
> calibration.
> 
> Signed-off-by: Aapo Vienamo <avienamo@nvidia.com>
> ---
>   drivers/mmc/host/sdhci-tegra.c | 24 +++++++++++++++++++-----
>   1 file changed, 19 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index f108c48..e40ca43 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -49,6 +49,9 @@
>   #define SDHCI_AUTO_CAL_START			BIT(31)
>   #define SDHCI_AUTO_CAL_ENABLE			BIT(29)
>   
> +#define SDHCI_TEGRA_AUTO_CAL_STATUS     0x1ec
> +#define SDHCI_TEGRA_AUTO_CAL_ACTIVE     BIT(31)

Please align the definition value with tabs. Also it looks like the 
alignments for the defines here are all over the place, would be nice to 
fix those up so they line up.

> +
>   #define NVQUIRK_FORCE_SDHCI_SPEC_200	BIT(0)
>   #define NVQUIRK_ENABLE_BLOCK_GAP_DET	BIT(1)
>   #define NVQUIRK_ENABLE_SDHCI_SPEC_300	BIT(2)
> @@ -198,13 +201,24 @@ static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask)
>   
>   static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
>   {
> -	u32 val;
> +	unsigned timeout = 10;

I prefer "unsigned int" instead of just "unsigned", but I guess that's 
just a personal preference..

> +	u32 reg;
>   
> -	mdelay(1);
> +	reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
> +	reg |= SDHCI_AUTO_CAL_ENABLE | SDHCI_AUTO_CAL_START;
> +	sdhci_writel(host, reg, SDHCI_TEGRA_AUTO_CAL_CONFIG);
> +	udelay(1);
> +
> +	do {
> +		reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_STATUS);
> +		if (!(reg & SDHCI_TEGRA_AUTO_CAL_ACTIVE))
> +			break;
> +		mdelay(1);
> +		timeout--;
> +	} while (timeout);

Can we use readl_poll_timeout here? We'll need to calculate the address 
directly but it'd still look nicer.

Cheers,
Mikko

>   
> -	val = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
> -	val |= SDHCI_AUTO_CAL_ENABLE | SDHCI_AUTO_CAL_START;
> -	sdhci_writel(host,val, SDHCI_TEGRA_AUTO_CAL_CONFIG);
> +	if (timeout == 0)
> +		dev_err(mmc_dev(host->mmc), "Pad autocal timed out\n");
>   }
>   
>   static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
> 
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diff mbox series

Patch

diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index f108c48..e40ca43 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -49,6 +49,9 @@ 
 #define SDHCI_AUTO_CAL_START			BIT(31)
 #define SDHCI_AUTO_CAL_ENABLE			BIT(29)
 
+#define SDHCI_TEGRA_AUTO_CAL_STATUS     0x1ec
+#define SDHCI_TEGRA_AUTO_CAL_ACTIVE     BIT(31)
+
 #define NVQUIRK_FORCE_SDHCI_SPEC_200	BIT(0)
 #define NVQUIRK_ENABLE_BLOCK_GAP_DET	BIT(1)
 #define NVQUIRK_ENABLE_SDHCI_SPEC_300	BIT(2)
@@ -198,13 +201,24 @@  static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask)
 
 static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
 {
-	u32 val;
+	unsigned timeout = 10;
+	u32 reg;
 
-	mdelay(1);
+	reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+	reg |= SDHCI_AUTO_CAL_ENABLE | SDHCI_AUTO_CAL_START;
+	sdhci_writel(host, reg, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+	udelay(1);
+
+	do {
+		reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_STATUS);
+		if (!(reg & SDHCI_TEGRA_AUTO_CAL_ACTIVE))
+			break;
+		mdelay(1);
+		timeout--;
+	} while (timeout);
 
-	val = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
-	val |= SDHCI_AUTO_CAL_ENABLE | SDHCI_AUTO_CAL_START;
-	sdhci_writel(host,val, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+	if (timeout == 0)
+		dev_err(mmc_dev(host->mmc), "Pad autocal timed out\n");
 }
 
 static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)