[PATCH v2] mmc: mxs-mmc: Introduce regulator support

[PATCH v2] mmc: mxs-mmc: Introduce regulator support

[Martin Kepplinger]

From: Martin Kepplinger <martin.kepplinger@ginzinger.com>

This adds support for explicitly switching the mmc's power on and off
which is needed for example for WL1837 wifi controllers. ip link set wlan0 down
doesn't turn off the VMMC regulator which leads to hangs when loading firmware.

Tested on i.MX28.

Signed-off-by: Martin Kepplinger <martin.kepplinger@ginzinger.com>
---

again, this isn't new. it's (rebased and simplified)
https://patchwork.kernel.org/patch/4365751/

Thanks Robin for your input!

revision history
----------------
v1: was just a question why this hasn't gone in earlier.


 drivers/mmc/host/mxs-mmc.c | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c
index add1e70195ea..fdaca0fcec99 100644
--- a/drivers/mmc/host/mxs-mmc.c
+++ b/drivers/mmc/host/mxs-mmc.c
@@ -66,11 +66,13 @@ struct mxs_mmc_host {
 	struct mmc_request		*mrq;
 	struct mmc_command		*cmd;
 	struct mmc_data			*data;
+	struct regulator		*vmmc;
 
 	unsigned char			bus_width;
 	spinlock_t			lock;
 	int				sdio_irq_en;
 	bool				broken_cd;
+	unsigned char			power_mode;
 };
 
 static int mxs_mmc_get_cd(struct mmc_host *mmc)
@@ -517,6 +519,24 @@ static void mxs_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 	else
 		host->bus_width = 0;
 
+	if (host->vmmc && ios->power_mode != host->power_mode) {
+		switch (ios->power_mode) {
+		case MMC_POWER_OFF:
+			if (regulator_disable(host->vmmc))
+				dev_err(mmc_dev(host->mmc),
+					"Failed to disable vmmc regulator\n");
+			break;
+		case MMC_POWER_UP:
+			if (regulator_enable(host->vmmc))
+				dev_err(mmc_dev(host->mmc),
+					"Failed to enable vmmc regulator\n");
+			break;
+		default:
+			break;
+		}
+		host->power_mode = ios->power_mode;
+	}
+
 	if (ios->clock)
 		mxs_ssp_set_clk_rate(&host->ssp, ios->clock);
 }
@@ -613,16 +633,11 @@ static int mxs_mmc_probe(struct platform_device *pdev)
 
 	host->mmc = mmc;
 	host->sdio_irq_en = 0;
+	host->power_mode = MMC_POWER_OFF;
 
 	reg_vmmc = devm_regulator_get(&pdev->dev, "vmmc");
-	if (!IS_ERR(reg_vmmc)) {
-		ret = regulator_enable(reg_vmmc);
-		if (ret) {
-			dev_err(&pdev->dev,
-				"Failed to enable vmmc regulator: %d\n", ret);
-			goto out_mmc_free;
-		}
-	}
+	if (!IS_ERR(reg_vmmc))
+		host->vmmc = reg_vmmc;
 
 	ssp->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(ssp->clk)) {
-- 
2.20.1


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Re: [PATCH v2] mmc: mxs-mmc: Introduce regulator support

[Robin van der Gracht]

Hi Martin,

On Mon, 28 Jan 2019 11:20:22 +0100
Martin Kepplinger <martink@posteo.de> wrote:

> From: Martin Kepplinger <martin.kepplinger@ginzinger.com>
> 
> This adds support for explicitly switching the mmc's power on and off
> which is needed for example for WL1837 wifi controllers. ip link set wlan0 down
> doesn't turn off the VMMC regulator which leads to hangs when loading firmware.
> 
> Tested on i.MX28.
> 
> Signed-off-by: Martin Kepplinger <martin.kepplinger@ginzinger.com>
> ---
> 
> again, this isn't new. it's (rebased and simplified)
> https://patchwork.kernel.org/patch/4365751/
> 
> Thanks Robin for your input!
> 
> revision history
> ----------------
> v1: was just a question why this hasn't gone in earlier.

Not sure why it never made it. I created it for use with a wl1271 which
wan't properly reset in case of a fault. Also combined with imx28.

Regards,
Robin van der Gracht

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Re: [PATCH v2] mmc: mxs-mmc: Introduce regulator support

[Ulf Hansson]

On Mon, 28 Jan 2019 at 11:20, Martin Kepplinger <martink@posteo.de> wrote:
>
> From: Martin Kepplinger <martin.kepplinger@ginzinger.com>
>
> This adds support for explicitly switching the mmc's power on and off
> which is needed for example for WL1837 wifi controllers. ip link set wlan0 down
> doesn't turn off the VMMC regulator which leads to hangs when loading firmware.

Isn't there a GPIO that needs to be toggled and separate clk for the
WiFi chip that needs to be enabled as well?

>
> Tested on i.MX28.
>
> Signed-off-by: Martin Kepplinger <martin.kepplinger@ginzinger.com>
> ---
>
> again, this isn't new. it's (rebased and simplified)
> https://patchwork.kernel.org/patch/4365751/
>
> Thanks Robin for your input!
>
> revision history
> ----------------
> v1: was just a question why this hasn't gone in earlier.
>
>
>  drivers/mmc/host/mxs-mmc.c | 31 +++++++++++++++++++++++--------
>  1 file changed, 23 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c
> index add1e70195ea..fdaca0fcec99 100644
> --- a/drivers/mmc/host/mxs-mmc.c
> +++ b/drivers/mmc/host/mxs-mmc.c
> @@ -66,11 +66,13 @@ struct mxs_mmc_host {
>         struct mmc_request              *mrq;
>         struct mmc_command              *cmd;
>         struct mmc_data                 *data;
> +       struct regulator                *vmmc;

You don't need this here as this is already part of the generic struct
mmc_host (via the struct mmc_supply).

>
>         unsigned char                   bus_width;
>         spinlock_t                      lock;
>         int                             sdio_irq_en;
>         bool                            broken_cd;
> +       unsigned char                   power_mode;

Ditto.

>  };
>
>  static int mxs_mmc_get_cd(struct mmc_host *mmc)
> @@ -517,6 +519,24 @@ static void mxs_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>         else
>                 host->bus_width = 0;
>
> +       if (host->vmmc && ios->power_mode != host->power_mode) {
> +               switch (ios->power_mode) {
> +               case MMC_POWER_OFF:
> +                       if (regulator_disable(host->vmmc))
> +                               dev_err(mmc_dev(host->mmc),
> +                                       "Failed to disable vmmc regulator\n");

You should use mmc_regulator_set_ocr() instead.

> +                       break;
> +               case MMC_POWER_UP:
> +                       if (regulator_enable(host->vmmc))

Ditto.

> +                               dev_err(mmc_dev(host->mmc),
> +                                       "Failed to enable vmmc regulator\n");
> +                       break;
> +               default:
> +                       break;
> +               }
> +               host->power_mode = ios->power_mode;
> +       }
> +
>         if (ios->clock)
>                 mxs_ssp_set_clk_rate(&host->ssp, ios->clock);
>  }
> @@ -613,16 +633,11 @@ static int mxs_mmc_probe(struct platform_device *pdev)
>
>         host->mmc = mmc;
>         host->sdio_irq_en = 0;
> +       host->power_mode = MMC_POWER_OFF;

This isn't needed. The state is already controlled by the mmc core.

>
>         reg_vmmc = devm_regulator_get(&pdev->dev, "vmmc");

You should use mmc_regulator_get_supply() instead.

> -       if (!IS_ERR(reg_vmmc)) {
> -               ret = regulator_enable(reg_vmmc);
> -               if (ret) {
> -                       dev_err(&pdev->dev,
> -                               "Failed to enable vmmc regulator: %d\n", ret);
> -                       goto out_mmc_free;
> -               }
> -       }
> +       if (!IS_ERR(reg_vmmc))
> +               host->vmmc = reg_vmmc;
>
>         ssp->clk = devm_clk_get(&pdev->dev, NULL);
>         if (IS_ERR(ssp->clk)) {
> --
> 2.20.1
>

Kind regards
Uffe

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