From 247cfe53557524a94dd1001d19e5aa50bd5aca81 Mon Sep 17 00:00:00 2001 From: Kyle Roeschley Date: Fri, 13 Apr 2018 16:54:57 -0500 Subject: [PATCH] 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: Kyle Roeschley Signed-off-by: Jennifer Dahm Signed-off-by: Ulf Hansson --- drivers/mmc/core/mmc.c | 8 ++++++++ drivers/mmc/core/sd.c | 8 ++++++++ drivers/mmc/core/sdio.c | 8 ++++++++ include/linux/mmc/host.h | 1 + 4 files changed, 25 insertions(+) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 6f8ebd6caa4c..915b58f9bfc5 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -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; diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index baf3d5da4ccb..7f87a5354f9f 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -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; diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c index 24b510b743da..87e53a721a10 100644 --- a/drivers/mmc/core/sdio.c +++ b/drivers/mmc/core/sdio.c @@ -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; diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 85146235231e..7c6eaf63f5ce 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -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 */