Commit 247cfe53 authored by Kyle Roeschley's avatar Kyle Roeschley Committed by Ulf Hansson
Browse files

mmc: core: Add capability to avoid 3.3V signaling 



Some SD host controllers cannot handle extended use of 3.3V signaling.
To accommodate these controllers, add a capability that requires us to
negotiate the voltage down from 3.3V during card initialization.

Signed-off-by: default avatarKyle Roeschley <kyle.roeschley@ni.com>
Signed-off-by: default avatarJennifer Dahm <jennifer.dahm@ni.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 1d6efe08

drivers/mmc/core/mmc.c

+8 −0
Original line number Diff line number Diff line
@@ -1830,6 +1830,14 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, 
		}

	}



	if (host->caps2 & MMC_CAP2_AVOID_3_3V &&

	    host->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_330) {

		pr_err("%s: Host failed to negotiate down from 3.3V\n",

			mmc_hostname(host));

		err = -EINVAL;

		goto free_card;

	}



	if (!oldcard)

		host->card = card;

drivers/mmc/core/sd.c

+8 −0
Original line number Diff line number Diff line
@@ -1058,6 +1058,14 @@ retry: 
			mmc_set_bus_width(host, MMC_BUS_WIDTH_4);

		}

	}



	if (host->caps2 & MMC_CAP2_AVOID_3_3V &&

	    host->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_330) {

		pr_err("%s: Host failed to negotiate down from 3.3V\n",

			mmc_hostname(host));

		err = -EINVAL;

		goto free_card;

	}

done:

	host->card = card;

	return 0;

drivers/mmc/core/sdio.c

+8 −0
Original line number Diff line number Diff line
@@ -792,6 +792,14 @@ try_again: 
		if (err)

			goto remove;

	}



	if (host->caps2 & MMC_CAP2_AVOID_3_3V &&

	    host->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_330) {

		pr_err("%s: Host failed to negotiate down from 3.3V\n",

			mmc_hostname(host));

		err = -EINVAL;

		goto remove;

	}

finish:

	if (!oldcard)

		host->card = card;

include/linux/mmc/host.h

+1 −0
Original line number Diff line number Diff line
@@ -354,6 +354,7 @@ struct mmc_host { 
#define MMC_CAP2_NO_MMC		(1 << 22)	/* Do not send (e)MMC commands during initialization */

#define MMC_CAP2_CQE		(1 << 23)	/* Has eMMC command queue engine */

#define MMC_CAP2_CQE_DCMD	(1 << 24)	/* CQE can issue a direct command */

#define MMC_CAP2_AVOID_3_3V	(1 << 25)	/* Host must negotiate down from 3.3V */



	int			fixed_drv_type;	/* fixed driver type for non-removable media */

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