diff mbox

[2/2] mmc: sd: Fix sd current limit setting

Message ID 20120718062223.GA2711@aarontestpc.amd.com (mailing list archive)
State New, archived
Headers show

Commit Message

aaron lu July 18, 2012, 6:22 a.m. UTC 
Hi Chris,

On Wed, Jul 18, 2012 at 01:28:40AM -0400, Chris Ball wrote:
> Hi Aaron,
> 
> On Wed, Jul 18 2012, Aaron Lu wrote:
> > Is the following patch OK? This is based on top of current mmc-next with
> > the previous one in tree. Not sure if this is what you want though.
> 
> Yes, that's perfect; squashed into the original patch and pushed out
> to mmc-next.  Thanks!
> 
> Having there be so many MAX_CURRENT defines -- and having them be
> split in the middle between CAP_ and CAP2_ -- is starting to feel
> a bit awkward.

I agree.

> Does anyone have ideas on how that might be tidied up,
> since we have an opportunity to come up with a better plan
> before this gets merged soon?

What about we add three fields in mmc_host to store the max current
value for 3.3v/3.0v/1.8v and use that when needed instead of the cap
setting of the host?

I've prepared the following code, please check if this is better than
the current one:



Thanks,
Aaron

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Comments

Chris Ball July 19, 2012, 2:41 a.m. UTC | #1 
Hi,

On Wed, Jul 18 2012, Aaron Lu wrote:
> I've prepared the following code, please check if this is better than
> the current one:

I think the diffstat speaks for itself.  :-)

 drivers/mmc/core/sd.c    |   77 ++++++++++++++++++++++++++--------------------
 drivers/mmc/host/sdhci.c |   51 ++----------------------------
 include/linux/mmc/host.h |   22 +++----------
 3 files changed, 51 insertions(+), 99 deletions(-)

Girish/Philip, does this look good to you too?  If so, I'll squash it
into the original patch.

Thanks!

- Chris.
Philip Rakity July 19, 2012, 3:47 a.m. UTC | #2 
It is much cleaner solution then before !  I like it.

Reviewed-by: Philip Rakity <prakity@marvell.com>

On Jul 18, 2012, at 7:41 PM, Chris Ball wrote:

> Hi,
> 
> On Wed, Jul 18 2012, Aaron Lu wrote:
>> I've prepared the following code, please check if this is better than
>> the current one:
> 
> I think the diffstat speaks for itself.  :-)
> 
> drivers/mmc/core/sd.c    |   77 ++++++++++++++++++++++++++--------------------
> drivers/mmc/host/sdhci.c |   51 ++----------------------------
> include/linux/mmc/host.h |   22 +++----------
> 3 files changed, 51 insertions(+), 99 deletions(-)
> 
> Girish/Philip, does this look good to you too?  If so, I'll squash it
> into the original patch.
> 
> Thanks!
> 
> - Chris.
> -- 
> Chris Ball   <cjb@laptop.org>   <http://printf.net/>
> One Laptop Per Child

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Girish K S July 19, 2012, 4:47 a.m. UTC | #3 
On 18 July 2012 11:52, Aaron Lu <aaron.lu@amd.com> wrote:
> Hi Chris,
>
> On Wed, Jul 18, 2012 at 01:28:40AM -0400, Chris Ball wrote:
>> Hi Aaron,
>>
>> On Wed, Jul 18 2012, Aaron Lu wrote:
>> > Is the following patch OK? This is based on top of current mmc-next with
>> > the previous one in tree. Not sure if this is what you want though.
>>
>> Yes, that's perfect; squashed into the original patch and pushed out
>> to mmc-next.  Thanks!
>>
>> Having there be so many MAX_CURRENT defines -- and having them be
>> split in the middle between CAP_ and CAP2_ -- is starting to feel
>> a bit awkward.
>
> I agree.
>
>> Does anyone have ideas on how that might be tidied up,
>> since we have an opportunity to come up with a better plan
>> before this gets merged soon?
>
> What about we add three fields in mmc_host to store the max current
> value for 3.3v/3.0v/1.8v and use that when needed instead of the cap
> setting of the host?
>
> I've prepared the following code, please check if this is better than
> the current one:
>
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
> index 312b78d..2232004 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -517,11 +517,36 @@ static int sd_set_bus_speed_mode(struct mmc_card *card, u8 *status)
>         return 0;
>  }
>
> +/* Get host's max current setting at its current voltage */
> +static u32 sd_get_host_max_current(struct mmc_host *host)
> +{
> +       u32 voltage, max_current;
> +
> +       voltage = 1 << host->ios.vdd;
> +       switch (voltage) {
> +       case MMC_VDD_165_195:
> +               max_current = host->max_current_180;
> +               break;
> +       case MMC_VDD_29_30:
> +       case MMC_VDD_30_31:
> +               max_current = host->max_current_300;
> +               break;
> +       case MMC_VDD_32_33:
> +       case MMC_VDD_33_34:
> +               max_current = host->max_current_330;
> +               break;
> +       default:
> +               max_current = 0;
> +       }
> +
> +       return max_current;
> +}
> +
>  static int sd_set_current_limit(struct mmc_card *card, u8 *status)
>  {
>         int current_limit = SD_SET_CURRENT_NO_CHANGE;
>         int err;
> -       u32 voltage;
> +       u32 max_current;
>
>         /*
>          * Current limit switch is only defined for SDR50, SDR104, and DDR50
> @@ -535,9 +560,9 @@ static int sd_set_current_limit(struct mmc_card *card, u8 *status)
>
>         /*
>          * Host has different current capabilities when operating at
> -        * different voltages, so find out the current voltage first.
> +        * different voltages, so find out its max current first.
>          */
> -       voltage = 1 << card->host->ios.vdd;
> +       max_current = sd_get_host_max_current(card->host);
>
>         /*
>          * We only check host's capability here, if we set a limit that is
> @@ -547,34 +572,15 @@ static int sd_set_current_limit(struct mmc_card *card, u8 *status)
>          * when we set current limit to 400/600/800ma, the card will draw its
>          * maximum 300ma from the host.
>          */
> -       if (voltage == MMC_VDD_165_195) {
> -               if (card->host->caps & MMC_CAP_MAX_CURRENT_800_180)
> -                       current_limit = SD_SET_CURRENT_LIMIT_800;
> -               else if (card->host->caps & MMC_CAP_MAX_CURRENT_600_180)
> -                       current_limit = SD_SET_CURRENT_LIMIT_600;
> -               else if (card->host->caps & MMC_CAP_MAX_CURRENT_400_180)
> -                       current_limit = SD_SET_CURRENT_LIMIT_400;
> -               else if (card->host->caps & MMC_CAP_MAX_CURRENT_200_180)
> -                       current_limit = SD_SET_CURRENT_LIMIT_200;
> -       } else if (voltage & (MMC_VDD_29_30 | MMC_VDD_30_31)) {
> -               if (card->host->caps & MMC_CAP_MAX_CURRENT_800_300)
> -                       current_limit = SD_SET_CURRENT_LIMIT_800;
> -               else if (card->host->caps & MMC_CAP_MAX_CURRENT_600_300)
> -                       current_limit = SD_SET_CURRENT_LIMIT_600;
> -               else if (card->host->caps & MMC_CAP_MAX_CURRENT_400_300)
> -                       current_limit = SD_SET_CURRENT_LIMIT_400;
> -               else if (card->host->caps & MMC_CAP_MAX_CURRENT_200_300)
> -                       current_limit = SD_SET_CURRENT_LIMIT_200;
> -       } else if (voltage & (MMC_VDD_32_33 | MMC_VDD_33_34)) {
> -               if (card->host->caps & MMC_CAP_MAX_CURRENT_800_330)
> -                       current_limit = SD_SET_CURRENT_LIMIT_800;
> -               else if (card->host->caps & MMC_CAP_MAX_CURRENT_600_330)
> -                       current_limit = SD_SET_CURRENT_LIMIT_600;
> -               else if (card->host->caps & MMC_CAP_MAX_CURRENT_400_330)
> -                       current_limit = SD_SET_CURRENT_LIMIT_400;
> -               else if (card->host->caps & MMC_CAP_MAX_CURRENT_200_330)
> -                       current_limit = SD_SET_CURRENT_LIMIT_200;
> -       }
> +
> +       if (max_current >= 800)
> +               current_limit = SD_SET_CURRENT_LIMIT_800;
> +       else if (max_current >= 600)
> +               current_limit = SD_SET_CURRENT_LIMIT_600;
> +       else if (max_current >= 400)
> +               current_limit = SD_SET_CURRENT_LIMIT_400;
> +       else if (max_current >= 200)
> +               current_limit = SD_SET_CURRENT_LIMIT_200;
>
>         if (current_limit != SD_SET_CURRENT_NO_CHANGE) {
>                 err = mmc_sd_switch(card, 1, 3, current_limit, status);
> @@ -707,6 +713,7 @@ struct device_type sd_type = {
>  int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid, u32 *rocr)
>  {
>         int err;
> +       u32 max_current;
>
>         /*
>          * Since we're changing the OCR value, we seem to
> @@ -734,9 +741,12 @@ int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid, u32 *rocr)
>             MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_DDR50))
>                 ocr |= SD_OCR_S18R;
>
> -       /* If the host can supply more than 150mA, XPC should be set to 1. */
> -       if (host->caps & (MMC_CAP_SET_XPC_330 | MMC_CAP_SET_XPC_300 |
> -           MMC_CAP_SET_XPC_180))
> +       /*
> +        * If the host can supply more than 150mA at current voltage,
> +        * XPC should be set to 1.
> +        */
> +       max_current = sd_get_host_max_current(host);
> +       if (max_current > 150)
>                 ocr |= SD_OCR_XPC;
>
>  try_again:
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 455a093..a72ad30 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2906,73 +2906,30 @@ int sdhci_add_host(struct sdhci_host *host)
>         }
>
>         if (caps[0] & SDHCI_CAN_VDD_330) {
> -               int max_current_330;
> -
>                 ocr_avail |= MMC_VDD_32_33 | MMC_VDD_33_34;
>
> -               max_current_330 = ((max_current_caps &
> +               mmc->max_current_330 = ((max_current_caps &
>                                    SDHCI_MAX_CURRENT_330_MASK) >>
>                                    SDHCI_MAX_CURRENT_330_SHIFT) *
>                                    SDHCI_MAX_CURRENT_MULTIPLIER;
>
> -               if (max_current_330 > 150)
> -                       mmc->caps |= MMC_CAP_SET_XPC_330;
> -
> -               /* Maximum current capabilities of the host at 3.3V */
> -               if (max_current_330 >= 800)
> -                       mmc->caps |= MMC_CAP_MAX_CURRENT_800_330;
> -               else if (max_current_330 >= 600)
> -                       mmc->caps |= MMC_CAP_MAX_CURRENT_600_330;
> -               else if (max_current_330 >= 400)
> -                       mmc->caps |= MMC_CAP_MAX_CURRENT_400_330;
> -               else if (max_current_330 >= 200)
> -                       mmc->caps |= MMC_CAP_MAX_CURRENT_200_330;
>         }
>         if (caps[0] & SDHCI_CAN_VDD_300) {
> -               int max_current_300;
> -
>                 ocr_avail |= MMC_VDD_29_30 | MMC_VDD_30_31;
>
> -               max_current_300 = ((max_current_caps &
> +               mmc->max_current_300 = ((max_current_caps &
>                                    SDHCI_MAX_CURRENT_300_MASK) >>
>                                    SDHCI_MAX_CURRENT_300_SHIFT) *
>                                    SDHCI_MAX_CURRENT_MULTIPLIER;
>
> -               if (max_current_300 > 150)
> -                       mmc->caps |= MMC_CAP_SET_XPC_300;
> -
> -               /* Maximum current capabilities of the host at 3.0V */
> -               if (max_current_300 >= 800)
> -                       mmc->caps |= MMC_CAP_MAX_CURRENT_800_300;
> -               else if (max_current_300 >= 600)
> -                       mmc->caps |= MMC_CAP_MAX_CURRENT_600_300;
> -               else if (max_current_300 >= 400)
> -                       mmc->caps |= MMC_CAP_MAX_CURRENT_400_300;
> -               else if (max_current_300 >= 200)
> -                       mmc->caps |= MMC_CAP_MAX_CURRENT_200_300;
>         }
>         if (caps[0] & SDHCI_CAN_VDD_180) {
> -               int max_current_180;
> -
>                 ocr_avail |= MMC_VDD_165_195;
>
> -               max_current_180 = ((max_current_caps &
> +               mmc->max_current_180 = ((max_current_caps &
>                                    SDHCI_MAX_CURRENT_180_MASK) >>
>                                    SDHCI_MAX_CURRENT_180_SHIFT) *
>                                    SDHCI_MAX_CURRENT_MULTIPLIER;
> -
> -               if (max_current_180 > 150)
> -                       mmc->caps |= MMC_CAP_SET_XPC_180;
> -
> -               /* Maximum current capabilities of the host at 1.8V */
> -               if (max_current_180 >= 800)
> -                       mmc->caps |= MMC_CAP_MAX_CURRENT_800_180;
> -               else if (max_current_180 >= 600)
> -                       mmc->caps |= MMC_CAP_MAX_CURRENT_600_180;
> -               else if (max_current_180 >= 400)
> -                       mmc->caps |= MMC_CAP_MAX_CURRENT_400_180;
> -               else if (max_current_180 >= 200)
> -                       mmc->caps |= MMC_CAP_MAX_CURRENT_200_180;
>         }
>
>         mmc->ocr_avail = ocr_avail;
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 79d8921..8d2c052 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -189,6 +189,9 @@ struct mmc_host {
>         u32                     ocr_avail_sd;   /* SD-specific OCR */
>         u32                     ocr_avail_mmc;  /* MMC-specific OCR */
>         struct notifier_block   pm_notify;
> +       u32                     max_current_330;
> +       u32                     max_current_300;
> +       u32                     max_current_180;
>
>  #define MMC_VDD_165_195                0x00000080      /* VDD voltage 1.65 - 1.95 */
>  #define MMC_VDD_20_21          0x00000100      /* VDD voltage 2.0 ~ 2.1 */
> @@ -232,16 +235,9 @@ struct mmc_host {
>  #define MMC_CAP_UHS_SDR50      (1 << 17)       /* Host supports UHS SDR50 mode */
>  #define MMC_CAP_UHS_SDR104     (1 << 18)       /* Host supports UHS SDR104 mode */
>  #define MMC_CAP_UHS_DDR50      (1 << 19)       /* Host supports UHS DDR50 mode */
> -#define MMC_CAP_SET_XPC_330    (1 << 20)       /* Host supports >150mA current at 3.3V */
> -#define MMC_CAP_SET_XPC_300    (1 << 21)       /* Host supports >150mA current at 3.0V */
> -#define MMC_CAP_SET_XPC_180    (1 << 22)       /* Host supports >150mA current at 1.8V */
>  #define MMC_CAP_DRIVER_TYPE_A  (1 << 23)       /* Host supports Driver Type A */
>  #define MMC_CAP_DRIVER_TYPE_C  (1 << 24)       /* Host supports Driver Type C */
>  #define MMC_CAP_DRIVER_TYPE_D  (1 << 25)       /* Host supports Driver Type D */
> -#define MMC_CAP_MAX_CURRENT_200_180 (1 << 26)  /* Host max current limit is 200mA at 1.8V */
> -#define MMC_CAP_MAX_CURRENT_400_180 (1 << 27)  /* Host max current limit is 400mA at 1.8V */
> -#define MMC_CAP_MAX_CURRENT_600_180 (1 << 28)  /* Host max current limit is 600mA at 1.8V */
> -#define MMC_CAP_MAX_CURRENT_800_180 (1 << 29)  /* Host max current limit is 800mA at 1.8V */
>  #define MMC_CAP_CMD23          (1 << 30)       /* CMD23 supported. */
>  #define MMC_CAP_HW_RESET       (1 << 31)       /* Hardware reset */
>
> @@ -261,14 +257,6 @@ struct mmc_host {
>  #define MMC_CAP2_HC_ERASE_SZ   (1 << 9)        /* High-capacity erase size */
>  #define MMC_CAP2_CD_ACTIVE_HIGH        (1 << 10)       /* Card-detect signal active high */
>  #define MMC_CAP2_RO_ACTIVE_HIGH        (1 << 11)       /* Write-protect signal active high */
> -#define MMC_CAP_MAX_CURRENT_200_300 (1 << 12)  /* Host max current limit is 200mA at 3.0V */
> -#define MMC_CAP_MAX_CURRENT_400_300 (1 << 13)  /* Host max current limit is 400mA at 3.0V */
> -#define MMC_CAP_MAX_CURRENT_600_300 (1 << 14)  /* Host max current limit is 600mA at 3.0V */
> -#define MMC_CAP_MAX_CURRENT_800_300 (1 << 15)  /* Host max current limit is 800mA at 3.0V */
> -#define MMC_CAP_MAX_CURRENT_200_330 (1 << 16)  /* Host max current limit is 200mA at 3.3V */
> -#define MMC_CAP_MAX_CURRENT_400_330 (1 << 17)  /* Host max current limit is 400mA at 3.3V */
> -#define MMC_CAP_MAX_CURRENT_600_330 (1 << 18)  /* Host max current limit is 600mA at 3.3V */
> -#define MMC_CAP_MAX_CURRENT_800_330 (1 << 19)  /* Host max current limit is 800mA at 3.3V */
>  #define MMC_CAP2_PACKED_RD         (1 << 20)   /* Allow packed read */
>  #define MMC_CAP2_PACKED_WR         (1 << 21)   /* Allow packed write */
>  #define MMC_CAP2_PACKED_CMD    (MMC_CAP2_PACKED_RD | \
>
Looks like a better solution than earlier one.
Reviewed By: Girish K S <girish.shivananjappa@linaro.org>

Chris,
How about the holes created by removal of caps2 macros. Will they be
adjusted to follow the sequence or left as it is for future use.
>
> Thanks,
> Aaron
>
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Chris Ball July 19, 2012, 5:03 a.m. UTC | #4 
Hi,

On Thu, Jul 19 2012, Girish K S wrote:
> Looks like a better solution than earlier one.
> Reviewed By: Girish K S <girish.shivananjappa@linaro.org>

Thanks.

> Chris,
> How about the holes created by removal of caps2 macros. Will they be
> adjusted to follow the sequence or left as it is for future use.

There actually isn't a hole in caps2, since yesterday I told Seungwon
and Maya that I think the packed-write patches are not ready for 3.6 and
probably should wait another cycle:

http://marc.info/?l=linux-mmc&m=134259666416161&w=2

I'll be removing them from mmc-next, unless something changes.
There aren't any other caps creating a hole in caps2.

There's a hole in caps1, though.  I think we'll just wait for the next
patches that want caps to take the place of the hole in caps1 without
renumbering any extant caps.  Let me know if you disagree.

Thanks,

- Chris.
Chris Ball July 19, 2012, 6:25 a.m. UTC | #5 
Hi,

On Wed, Jul 18 2012, Chris Ball wrote:
> Girish/Philip, does this look good to you too?  If so, I'll squash it
> into the original patch.

Thanks, everyone -- squashed in and pushed out to mmc-next.

- Chris.
diff mbox

Patch

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 312b78d..2232004 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -517,11 +517,36 @@  static int sd_set_bus_speed_mode(struct mmc_card *card, u8 *status)
 	return 0;
 }
 
+/* Get host's max current setting at its current voltage */
+static u32 sd_get_host_max_current(struct mmc_host *host)
+{
+	u32 voltage, max_current;
+
+	voltage = 1 << host->ios.vdd;
+	switch (voltage) {
+	case MMC_VDD_165_195:
+		max_current = host->max_current_180;
+		break;
+	case MMC_VDD_29_30:
+	case MMC_VDD_30_31:
+		max_current = host->max_current_300;
+		break;
+	case MMC_VDD_32_33:
+	case MMC_VDD_33_34:
+		max_current = host->max_current_330;
+		break;
+	default:
+		max_current = 0;
+	}
+
+	return max_current;
+}
+
 static int sd_set_current_limit(struct mmc_card *card, u8 *status)
 {
 	int current_limit = SD_SET_CURRENT_NO_CHANGE;
 	int err;
-	u32 voltage;
+	u32 max_current;
 
 	/*
 	 * Current limit switch is only defined for SDR50, SDR104, and DDR50
@@ -535,9 +560,9 @@  static int sd_set_current_limit(struct mmc_card *card, u8 *status)
 
 	/*
 	 * Host has different current capabilities when operating at
-	 * different voltages, so find out the current voltage first.
+	 * different voltages, so find out its max current first.
 	 */
-	voltage = 1 << card->host->ios.vdd;
+	max_current = sd_get_host_max_current(card->host);
 
 	/*
 	 * We only check host's capability here, if we set a limit that is
@@ -547,34 +572,15 @@  static int sd_set_current_limit(struct mmc_card *card, u8 *status)
 	 * when we set current limit to 400/600/800ma, the card will draw its
 	 * maximum 300ma from the host.
 	 */
-	if (voltage == MMC_VDD_165_195) {
-		if (card->host->caps & MMC_CAP_MAX_CURRENT_800_180)
-			current_limit = SD_SET_CURRENT_LIMIT_800;
-		else if (card->host->caps & MMC_CAP_MAX_CURRENT_600_180)
-			current_limit = SD_SET_CURRENT_LIMIT_600;
-		else if (card->host->caps & MMC_CAP_MAX_CURRENT_400_180)
-			current_limit = SD_SET_CURRENT_LIMIT_400;
-		else if (card->host->caps & MMC_CAP_MAX_CURRENT_200_180)
-			current_limit = SD_SET_CURRENT_LIMIT_200;
-	} else if (voltage & (MMC_VDD_29_30 | MMC_VDD_30_31)) {
-		if (card->host->caps & MMC_CAP_MAX_CURRENT_800_300)
-			current_limit = SD_SET_CURRENT_LIMIT_800;
-		else if (card->host->caps & MMC_CAP_MAX_CURRENT_600_300)
-			current_limit = SD_SET_CURRENT_LIMIT_600;
-		else if (card->host->caps & MMC_CAP_MAX_CURRENT_400_300)
-			current_limit = SD_SET_CURRENT_LIMIT_400;
-		else if (card->host->caps & MMC_CAP_MAX_CURRENT_200_300)
-			current_limit = SD_SET_CURRENT_LIMIT_200;
-	} else if (voltage & (MMC_VDD_32_33 | MMC_VDD_33_34)) {
-		if (card->host->caps & MMC_CAP_MAX_CURRENT_800_330)
-			current_limit = SD_SET_CURRENT_LIMIT_800;
-		else if (card->host->caps & MMC_CAP_MAX_CURRENT_600_330)
-			current_limit = SD_SET_CURRENT_LIMIT_600;
-		else if (card->host->caps & MMC_CAP_MAX_CURRENT_400_330)
-			current_limit = SD_SET_CURRENT_LIMIT_400;
-		else if (card->host->caps & MMC_CAP_MAX_CURRENT_200_330)
-			current_limit = SD_SET_CURRENT_LIMIT_200;
-	}
+
+	if (max_current >= 800)
+		current_limit = SD_SET_CURRENT_LIMIT_800;
+	else if (max_current >= 600)
+		current_limit = SD_SET_CURRENT_LIMIT_600;
+	else if (max_current >= 400)
+		current_limit = SD_SET_CURRENT_LIMIT_400;
+	else if (max_current >= 200)
+		current_limit = SD_SET_CURRENT_LIMIT_200;
 
 	if (current_limit != SD_SET_CURRENT_NO_CHANGE) {
 		err = mmc_sd_switch(card, 1, 3, current_limit, status);
@@ -707,6 +713,7 @@  struct device_type sd_type = {
 int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid, u32 *rocr)
 {
 	int err;
+	u32 max_current;
 
 	/*
 	 * Since we're changing the OCR value, we seem to
@@ -734,9 +741,12 @@  int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid, u32 *rocr)
 	    MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_DDR50))
 		ocr |= SD_OCR_S18R;
 
-	/* If the host can supply more than 150mA, XPC should be set to 1. */
-	if (host->caps & (MMC_CAP_SET_XPC_330 | MMC_CAP_SET_XPC_300 |
-	    MMC_CAP_SET_XPC_180))
+	/*
+	 * If the host can supply more than 150mA at current voltage,
+	 * XPC should be set to 1.
+	 */
+	max_current = sd_get_host_max_current(host);
+	if (max_current > 150)
 		ocr |= SD_OCR_XPC;
 
 try_again:
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 455a093..a72ad30 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2906,73 +2906,30 @@  int sdhci_add_host(struct sdhci_host *host)
 	}
 
 	if (caps[0] & SDHCI_CAN_VDD_330) {
-		int max_current_330;
-
 		ocr_avail |= MMC_VDD_32_33 | MMC_VDD_33_34;
 
-		max_current_330 = ((max_current_caps &
+		mmc->max_current_330 = ((max_current_caps &
 				   SDHCI_MAX_CURRENT_330_MASK) >>
 				   SDHCI_MAX_CURRENT_330_SHIFT) *
 				   SDHCI_MAX_CURRENT_MULTIPLIER;
 
-		if (max_current_330 > 150)
-			mmc->caps |= MMC_CAP_SET_XPC_330;
-
-		/* Maximum current capabilities of the host at 3.3V */
-		if (max_current_330 >= 800)
-			mmc->caps |= MMC_CAP_MAX_CURRENT_800_330;
-		else if (max_current_330 >= 600)
-			mmc->caps |= MMC_CAP_MAX_CURRENT_600_330;
-		else if (max_current_330 >= 400)
-			mmc->caps |= MMC_CAP_MAX_CURRENT_400_330;
-		else if (max_current_330 >= 200)
-			mmc->caps |= MMC_CAP_MAX_CURRENT_200_330;
 	}
 	if (caps[0] & SDHCI_CAN_VDD_300) {
-		int max_current_300;
-
 		ocr_avail |= MMC_VDD_29_30 | MMC_VDD_30_31;
 
-		max_current_300 = ((max_current_caps &
+		mmc->max_current_300 = ((max_current_caps &
 				   SDHCI_MAX_CURRENT_300_MASK) >>
 				   SDHCI_MAX_CURRENT_300_SHIFT) *
 				   SDHCI_MAX_CURRENT_MULTIPLIER;
 
-		if (max_current_300 > 150)
-			mmc->caps |= MMC_CAP_SET_XPC_300;
-
-		/* Maximum current capabilities of the host at 3.0V */
-		if (max_current_300 >= 800)
-			mmc->caps |= MMC_CAP_MAX_CURRENT_800_300;
-		else if (max_current_300 >= 600)
-			mmc->caps |= MMC_CAP_MAX_CURRENT_600_300;
-		else if (max_current_300 >= 400)
-			mmc->caps |= MMC_CAP_MAX_CURRENT_400_300;
-		else if (max_current_300 >= 200)
-			mmc->caps |= MMC_CAP_MAX_CURRENT_200_300;
 	}
 	if (caps[0] & SDHCI_CAN_VDD_180) {
-		int max_current_180;
-
 		ocr_avail |= MMC_VDD_165_195;
 
-		max_current_180 = ((max_current_caps &
+		mmc->max_current_180 = ((max_current_caps &
 				   SDHCI_MAX_CURRENT_180_MASK) >>
 				   SDHCI_MAX_CURRENT_180_SHIFT) *
 				   SDHCI_MAX_CURRENT_MULTIPLIER;
-
-		if (max_current_180 > 150)
-			mmc->caps |= MMC_CAP_SET_XPC_180;
-
-		/* Maximum current capabilities of the host at 1.8V */
-		if (max_current_180 >= 800)
-			mmc->caps |= MMC_CAP_MAX_CURRENT_800_180;
-		else if (max_current_180 >= 600)
-			mmc->caps |= MMC_CAP_MAX_CURRENT_600_180;
-		else if (max_current_180 >= 400)
-			mmc->caps |= MMC_CAP_MAX_CURRENT_400_180;
-		else if (max_current_180 >= 200)
-			mmc->caps |= MMC_CAP_MAX_CURRENT_200_180;
 	}
 
 	mmc->ocr_avail = ocr_avail;
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 79d8921..8d2c052 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -189,6 +189,9 @@  struct mmc_host {
 	u32			ocr_avail_sd;	/* SD-specific OCR */
 	u32			ocr_avail_mmc;	/* MMC-specific OCR */
 	struct notifier_block	pm_notify;
+	u32			max_current_330;
+	u32			max_current_300;
+	u32			max_current_180;
 
 #define MMC_VDD_165_195		0x00000080	/* VDD voltage 1.65 - 1.95 */
 #define MMC_VDD_20_21		0x00000100	/* VDD voltage 2.0 ~ 2.1 */
@@ -232,16 +235,9 @@  struct mmc_host {
 #define MMC_CAP_UHS_SDR50	(1 << 17)	/* Host supports UHS SDR50 mode */
 #define MMC_CAP_UHS_SDR104	(1 << 18)	/* Host supports UHS SDR104 mode */
 #define MMC_CAP_UHS_DDR50	(1 << 19)	/* Host supports UHS DDR50 mode */
-#define MMC_CAP_SET_XPC_330	(1 << 20)	/* Host supports >150mA current at 3.3V */
-#define MMC_CAP_SET_XPC_300	(1 << 21)	/* Host supports >150mA current at 3.0V */
-#define MMC_CAP_SET_XPC_180	(1 << 22)	/* Host supports >150mA current at 1.8V */
 #define MMC_CAP_DRIVER_TYPE_A	(1 << 23)	/* Host supports Driver Type A */
 #define MMC_CAP_DRIVER_TYPE_C	(1 << 24)	/* Host supports Driver Type C */
 #define MMC_CAP_DRIVER_TYPE_D	(1 << 25)	/* Host supports Driver Type D */
-#define MMC_CAP_MAX_CURRENT_200_180 (1 << 26)	/* Host max current limit is 200mA at 1.8V */
-#define MMC_CAP_MAX_CURRENT_400_180 (1 << 27)	/* Host max current limit is 400mA at 1.8V */
-#define MMC_CAP_MAX_CURRENT_600_180 (1 << 28)	/* Host max current limit is 600mA at 1.8V */
-#define MMC_CAP_MAX_CURRENT_800_180 (1 << 29)	/* Host max current limit is 800mA at 1.8V */
 #define MMC_CAP_CMD23		(1 << 30)	/* CMD23 supported. */
 #define MMC_CAP_HW_RESET	(1 << 31)	/* Hardware reset */
 
@@ -261,14 +257,6 @@  struct mmc_host {
 #define MMC_CAP2_HC_ERASE_SZ	(1 << 9)	/* High-capacity erase size */
 #define MMC_CAP2_CD_ACTIVE_HIGH	(1 << 10)	/* Card-detect signal active high */
 #define MMC_CAP2_RO_ACTIVE_HIGH	(1 << 11)	/* Write-protect signal active high */
-#define MMC_CAP_MAX_CURRENT_200_300 (1 << 12)	/* Host max current limit is 200mA at 3.0V */
-#define MMC_CAP_MAX_CURRENT_400_300 (1 << 13)	/* Host max current limit is 400mA at 3.0V */
-#define MMC_CAP_MAX_CURRENT_600_300 (1 << 14)	/* Host max current limit is 600mA at 3.0V */
-#define MMC_CAP_MAX_CURRENT_800_300 (1 << 15)	/* Host max current limit is 800mA at 3.0V */
-#define MMC_CAP_MAX_CURRENT_200_330 (1 << 16)	/* Host max current limit is 200mA at 3.3V */
-#define MMC_CAP_MAX_CURRENT_400_330 (1 << 17)	/* Host max current limit is 400mA at 3.3V */
-#define MMC_CAP_MAX_CURRENT_600_330 (1 << 18)	/* Host max current limit is 600mA at 3.3V */
-#define MMC_CAP_MAX_CURRENT_800_330 (1 << 19)	/* Host max current limit is 800mA at 3.3V */
 #define MMC_CAP2_PACKED_RD	    (1 << 20)	/* Allow packed read */
 #define MMC_CAP2_PACKED_WR	    (1 << 21)	/* Allow packed write */
 #define MMC_CAP2_PACKED_CMD	(MMC_CAP2_PACKED_RD | \