From 41875e388401ad97c33252d5fa39d52e0b70ee9b Mon Sep 17 00:00:00 2001
From: Sujit Reddy Thumma <sthumma@codeaurora.org>
Date: Tue, 4 Dec 2012 17:06:19 +0530
Subject: [PATCH] mmc: sdio: Fix SDIO 3.0 UHS-I initialization sequence
According to UHS-I initialization sequence for SDIO 3.0 cards,
the host must set bit[24] (S18R) of OCR register during OCR
handshake to know whether the SDIO card is capable of doing
1.8V I/O.
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Johan Rudholm <johan.rudholm@stericsson.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
---
drivers/mmc/core/sdio.c | 22 +++++++++++-----------
include/linux/mmc/host.h | 8 ++++++++
2 files changed, 19 insertions(+), 11 deletions(-)
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 34ad4c877c1ff..9565d38d91a44 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -157,10 +157,7 @@ static int sdio_read_cccr(struct mmc_card *card, u32 ocr)
if (ret)
goto out;
- if (card->host->caps &
- (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
- MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
- MMC_CAP_UHS_DDR50)) {
+ if (mmc_host_uhs(card->host)) {
if (data & SDIO_UHS_DDR50)
card->sw_caps.sd3_bus_mode
|= SD_MODE_UHS_DDR50;
@@ -478,8 +475,7 @@ static int sdio_set_bus_speed_mode(struct mmc_card *card)
* If the host doesn't support any of the UHS-I modes, fallback on
* default speed.
*/
- if (!(card->host->caps & (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
- MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_DDR50)))
+ if (!mmc_host_uhs(card->host))
return 0;
bus_speed = SDIO_SPEED_SDR12;
@@ -645,11 +641,7 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
* systems that claim 1.8v signalling in fact do not support
* it.
*/
- if ((ocr & R4_18V_PRESENT) &&
- (host->caps &
- (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
- MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
- MMC_CAP_UHS_DDR50))) {
+ if ((ocr & R4_18V_PRESENT) && mmc_host_uhs(host)) {
err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180,
true);
if (err) {
@@ -1022,6 +1014,10 @@ static int mmc_sdio_power_restore(struct mmc_host *host)
goto out;
}
+ if (mmc_host_uhs(host))
+ /* to query card if 1.8V signalling is supported */
+ host->ocr |= R4_18V_PRESENT;
+
ret = mmc_sdio_init_card(host, host->ocr, host->card,
mmc_card_keep_power(host));
if (!ret && host->sdio_irqs)
@@ -1087,6 +1083,10 @@ int mmc_attach_sdio(struct mmc_host *host)
/*
* Detect and init the card.
*/
+ if (mmc_host_uhs(host))
+ /* to query card if 1.8V signalling is supported */
+ host->ocr |= R4_18V_PRESENT;
+
err = mmc_sdio_init_card(host, host->ocr, NULL, 0);
if (err) {
if (err == -EAGAIN) {
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 61a10c17aabd9..c89a1bb87fa5b 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -434,6 +434,14 @@ static inline int mmc_boot_partition_access(struct mmc_host *host)
return !(host->caps2 & MMC_CAP2_BOOTPART_NOACC);
}
+static inline int mmc_host_uhs(struct mmc_host *host)
+{
+ return host->caps &
+ (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
+ MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
+ MMC_CAP_UHS_DDR50);
+}
+
#ifdef CONFIG_MMC_CLKGATE
void mmc_host_clk_hold(struct mmc_host *host);
void mmc_host_clk_release(struct mmc_host *host);
--
2.30.2