diff mbox

[v2,2/7] mmc: sdhci-pxav3: Fix Armada 38x controller's caps according to erratum ERR-7878951

Message ID 1422010594-1735-3-git-send-email-gregory.clement@free-electrons.com (mailing list archive)
State New, archived
Headers show

Commit Message

Gregory CLEMENT Jan. 23, 2015, 10:56 a.m. UTC
From: Marcin Wojtas <mw@semihalf.com>

According to erratum 'ERR-7878951' Armada 38x SDHCI controller has
different capabilities than the ones shown in its registers:

- it doesn't support the voltage switching: it can work either with
  3.3V or 1.8V supply
- it doesn't support the SDR104 mode
- SDR50 mode doesn't need tuning

The SDHCI_QUIRK_MISSING_CAPS quirk is used for updating the
capabilities accordingly.

[gregory.clement@free-electrons.com: port from 3.10]

Fixes: 5491ce3f79ee ("mmc: sdhci-pxav3: add support for the Armada 38x SDHCI controller")
Cc: <stable@vger.kernel.org> # v3.15+

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
 drivers/mmc/host/sdhci-pxav3.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

Comments

Mark Rutland Jan. 23, 2015, 11:03 a.m. UTC | #1
[...]

> +	/*
> +	 * According to erratum 'ERR-7878951' Armada 38x SDHCI
> +	 * controller has different capabilities than the ones shown
> +	 * in its registers
> +	 */
> +	host->caps = sdhci_readl(host, SDHCI_CAPABILITIES);
> +	if (of_get_property(np, "no-1-8-v", NULL)) {

Please use of_property_read_bool(np, "no-1-8-v")

> +		host->caps &= ~SDHCI_CAN_VDD_180;
> +		host->mmc->caps &= ~MMC_CAP_1_8V_DDR;

Is SDHCI_CAN_VDD_330 always set elsewhere in this case?

> +	} else
> +		host->caps &= ~SDHCI_CAN_VDD_330;

If one branch in an if-else pair is braced, both sides should be (as
Documentation/CodingStyle says). Please brace the else case.

Thanks,
Mark.
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Marcin Wojtas Jan. 23, 2015, 11:12 a.m. UTC | #2
Hi Mark

2015-01-23 12:03 GMT+01:00 Mark Rutland <mark.rutland@arm.com>:
> [...]
>
>> +     /*
>> +      * According to erratum 'ERR-7878951' Armada 38x SDHCI
>> +      * controller has different capabilities than the ones shown
>> +      * in its registers
>> +      */
>> +     host->caps = sdhci_readl(host, SDHCI_CAPABILITIES);
>> +     if (of_get_property(np, "no-1-8-v", NULL)) {
>
> Please use of_property_read_bool(np, "no-1-8-v")
>
>> +             host->caps &= ~SDHCI_CAN_VDD_180;
>> +             host->mmc->caps &= ~MMC_CAP_1_8V_DDR;
>
> Is SDHCI_CAN_VDD_330 always set elsewhere in this case?

Yes, it's always set in SDHCI_CAPABILITIES register of Armada 38x
(assigned to host->caps few lines above), as well as
SDHCI_CAN_VDD_180. The point is, that in reality they can't be used
simultaneously for this device, i.e. voltage switching is impossible.

Thanks,
Marcin

>
>> +     } else
>> +             host->caps &= ~SDHCI_CAN_VDD_330;
>
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Marcin Wojtas Jan. 23, 2015, 11:33 a.m. UTC | #3
Dear Gregory,


> @@ -118,8 +118,11 @@ static int mv_conf_mbus_windows(struct platform_device *pdev,
>         return 0;
>  }
>
> -static int armada_38x_quirks(struct sdhci_host *host)
> +static int armada_38x_quirks(struct platform_device *pdev,
> +                            struct sdhci_host *host)
>  {
> +       struct device_node *np = pdev->dev.of_node;
> +
>         host->quirks |= SDHCI_QUIRK_MISSING_CAPS;
>         /*
>          * According to erratum 'FE-2946959' both SDR50 and DDR50
> @@ -129,6 +132,20 @@ static int armada_38x_quirks(struct sdhci_host *host)
>          */
>         host->caps1 = sdhci_readl(host, SDHCI_CAPABILITIES_1);
>         host->caps1 &= ~(SDHCI_SUPPORT_SDR50 | SDHCI_SUPPORT_DDR50);
> +
> +       /*
> +        * According to erratum 'ERR-7878951' Armada 38x SDHCI
> +        * controller has different capabilities than the ones shown
> +        * in its registers
> +        */
> +       host->caps = sdhci_readl(host, SDHCI_CAPABILITIES);
> +       if (of_get_property(np, "no-1-8-v", NULL)) {
> +               host->caps &= ~SDHCI_CAN_VDD_180;
> +               host->mmc->caps &= ~MMC_CAP_1_8V_DDR;
> +       } else
> +               host->caps &= ~SDHCI_CAN_VDD_330;

In this "else" there is one thing missing
host->mmc->caps |= MMC_CAP_1_8V_DDR;
because it's not set by default, however it's not a must - please see
my remark below.

> +       host->caps1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_USE_SDR50_TUNING);
> +
>         return 0;
>  }
>
> @@ -333,7 +350,7 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
>                 clk_prepare_enable(pxa->clk_core);
>
>         if (of_device_is_compatible(np, "marvell,armada-380-sdhci")) {
> -               ret = armada_38x_quirks(host);
> +               ret = armada_38x_quirks(pdev, host);
>                 if (ret < 0)
>                         goto err_quirks;
>                 ret = mv_conf_mbus_windows(pdev, mv_mbus_dram_info());
> @@ -341,9 +358,6 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
>                         goto err_mbus_win;
>         }
>
> -       /* enable 1/8V DDR capable */
> -       host->mmc->caps |= MMC_CAP_1_8V_DDR;
> -

Now, with this change MMC_CAP_1_8V_DDR is disabled for devices other
than Armada 38x, that use sdhci-pxav3. There are two options:
1. Move those lines above the place where armada_38x_quirks is called
(IMO the easiest option - 'else' in this function would not need to be
supplemented, as I pointed above)
2. Leave it "as is" here, but a condition below is needed (+
supplementation of 'else' in armada_38x_quirks)
 if (!of_device_is_compatible(np, "marvell,armada-380-sdhci"))

Best regards,
Marcin
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Gregory CLEMENT Jan. 23, 2015, 2:18 p.m. UTC | #4
Hi Marcin,

On 23/01/2015 12:33, Marcin Wojtas wrote:
> Dear Gregory,
> 
> 
>> @@ -118,8 +118,11 @@ static int mv_conf_mbus_windows(struct platform_device *pdev,
>>         return 0;
>>  }
>>
>> -static int armada_38x_quirks(struct sdhci_host *host)
>> +static int armada_38x_quirks(struct platform_device *pdev,
>> +                            struct sdhci_host *host)
>>  {
>> +       struct device_node *np = pdev->dev.of_node;
>> +
>>         host->quirks |= SDHCI_QUIRK_MISSING_CAPS;
>>         /*
>>          * According to erratum 'FE-2946959' both SDR50 and DDR50
>> @@ -129,6 +132,20 @@ static int armada_38x_quirks(struct sdhci_host *host)
>>          */
>>         host->caps1 = sdhci_readl(host, SDHCI_CAPABILITIES_1);
>>         host->caps1 &= ~(SDHCI_SUPPORT_SDR50 | SDHCI_SUPPORT_DDR50);
>> +
>> +       /*
>> +        * According to erratum 'ERR-7878951' Armada 38x SDHCI
>> +        * controller has different capabilities than the ones shown
>> +        * in its registers
>> +        */
>> +       host->caps = sdhci_readl(host, SDHCI_CAPABILITIES);
>> +       if (of_get_property(np, "no-1-8-v", NULL)) {
>> +               host->caps &= ~SDHCI_CAN_VDD_180;
>> +               host->mmc->caps &= ~MMC_CAP_1_8V_DDR;
>> +       } else
>> +               host->caps &= ~SDHCI_CAN_VDD_330;
> 
> In this "else" there is one thing missing
> host->mmc->caps |= MMC_CAP_1_8V_DDR;
> because it's not set by default, however it's not a must - please see
> my remark below.
> 
>> +       host->caps1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_USE_SDR50_TUNING);
>> +
>>         return 0;
>>  }
>>
>> @@ -333,7 +350,7 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
>>                 clk_prepare_enable(pxa->clk_core);
>>
>>         if (of_device_is_compatible(np, "marvell,armada-380-sdhci")) {
>> -               ret = armada_38x_quirks(host);
>> +               ret = armada_38x_quirks(pdev, host);
>>                 if (ret < 0)
>>                         goto err_quirks;
>>                 ret = mv_conf_mbus_windows(pdev, mv_mbus_dram_info());
>> @@ -341,9 +358,6 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
>>                         goto err_mbus_win;
>>         }
>>
>> -       /* enable 1/8V DDR capable */
>> -       host->mmc->caps |= MMC_CAP_1_8V_DDR;
>> -
> 
> Now, with this change MMC_CAP_1_8V_DDR is disabled for devices other
> than Armada 38x, that use sdhci-pxav3. There are two options:
> 1. Move those lines above the place where armada_38x_quirks is called
> (IMO the easiest option - 'else' in this function would not need to be
> supplemented, as I pointed above)
> 2. Leave it "as is" here, but a condition below is needed (+
> supplementation of 'else' in armada_38x_quirks)
>  if (!of_device_is_compatible(np, "marvell,armada-380-sdhci"))
> 

I will take the first option.

A third version is coming soon addressing also Mark's comments.

Thanks,

Gregory
diff mbox

Patch

diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c
index 7b07325b4fba..a53968010991 100644
--- a/drivers/mmc/host/sdhci-pxav3.c
+++ b/drivers/mmc/host/sdhci-pxav3.c
@@ -118,8 +118,11 @@  static int mv_conf_mbus_windows(struct platform_device *pdev,
 	return 0;
 }
 
-static int armada_38x_quirks(struct sdhci_host *host)
+static int armada_38x_quirks(struct platform_device *pdev,
+			     struct sdhci_host *host)
 {
+	struct device_node *np = pdev->dev.of_node;
+
 	host->quirks |= SDHCI_QUIRK_MISSING_CAPS;
 	/*
 	 * According to erratum 'FE-2946959' both SDR50 and DDR50
@@ -129,6 +132,20 @@  static int armada_38x_quirks(struct sdhci_host *host)
 	 */
 	host->caps1 = sdhci_readl(host, SDHCI_CAPABILITIES_1);
 	host->caps1 &= ~(SDHCI_SUPPORT_SDR50 | SDHCI_SUPPORT_DDR50);
+
+	/*
+	 * According to erratum 'ERR-7878951' Armada 38x SDHCI
+	 * controller has different capabilities than the ones shown
+	 * in its registers
+	 */
+	host->caps = sdhci_readl(host, SDHCI_CAPABILITIES);
+	if (of_get_property(np, "no-1-8-v", NULL)) {
+		host->caps &= ~SDHCI_CAN_VDD_180;
+		host->mmc->caps &= ~MMC_CAP_1_8V_DDR;
+	} else
+		host->caps &= ~SDHCI_CAN_VDD_330;
+	host->caps1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_USE_SDR50_TUNING);
+
 	return 0;
 }
 
@@ -333,7 +350,7 @@  static int sdhci_pxav3_probe(struct platform_device *pdev)
 		clk_prepare_enable(pxa->clk_core);
 
 	if (of_device_is_compatible(np, "marvell,armada-380-sdhci")) {
-		ret = armada_38x_quirks(host);
+		ret = armada_38x_quirks(pdev, host);
 		if (ret < 0)
 			goto err_quirks;
 		ret = mv_conf_mbus_windows(pdev, mv_mbus_dram_info());
@@ -341,9 +358,6 @@  static int sdhci_pxav3_probe(struct platform_device *pdev)
 			goto err_mbus_win;
 	}
 
-	/* enable 1/8V DDR capable */
-	host->mmc->caps |= MMC_CAP_1_8V_DDR;
-
 	match = of_match_device(of_match_ptr(sdhci_pxav3_of_match), &pdev->dev);
 	if (match) {
 		ret = mmc_of_parse(host->mmc);