[PATCH v2 2/6] mmc: core: add mmc-hs400-enhanced-strobe support

From: Shawn Lin
Date: Thu Apr 28 2016 - 22:47:29 EST


This patch introduce mmc-hs400-enhanced-strobe for platforms
which want to enable enhanced strobe function from DT if the
mmc host controller claims to support enhanced strobe.

Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>

---

Changes in v2:
- switch to HS400ES from Highspeed mode directly

drivers/mmc/core/host.c | 2 ++
include/linux/mmc/host.h | 6 ++++++
2 files changed, 8 insertions(+)

diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index e0a3ee1..eb1530a 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -289,6 +289,8 @@ int mmc_of_parse(struct mmc_host *host)
host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
if (of_property_read_bool(np, "mmc-hs400-1_2v"))
host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
+ if (of_property_read_bool(np, "mmc-hs400-enhanced-strobe"))
+ host->caps2 |= MMC_CAP2_HS400_ENHANCED_STROBE;

host->dsr_req = !of_property_read_u32(np, "dsr", &host->dsr);
if (host->dsr_req && (host->dsr & ~0xffff)) {
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 85800b4..11e89d3 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -302,6 +302,7 @@ struct mmc_host {
#define MMC_CAP2_SDIO_IRQ_NOTHREAD (1 << 17)
#define MMC_CAP2_NO_WRITE_PROTECT (1 << 18) /* No physical write protect pin, assume that card is always read-write */
#define MMC_CAP2_NO_SDIO (1 << 19) /* Do not send SDIO commands during initialization */
+#define MMC_CAP2_HS400_ENHANCED_STROBE (1 << 20) /* Host supports enhanced strobe */

mmc_pm_flag_t pm_caps; /* supported pm features */

@@ -480,6 +481,11 @@ static inline int mmc_host_uhs(struct mmc_host *host)
MMC_CAP_UHS_DDR50);
}

+static inline int mmc_host_hs400_enhanced_strobe(struct mmc_host *host)
+{
+ return host->caps2 & MMC_CAP2_HS400_ENHANCED_STROBE;
+}
+
static inline int mmc_host_packed_wr(struct mmc_host *host)
{
return host->caps2 & MMC_CAP2_PACKED_WR;
--
2.3.7