When switching card voltage to UHS voltage the mmc framework tries to
check that the card is driving pins CMD, and DAT[0-3] low before the
switch is made. Drivers that does not implement the card_busy function
will manage to do the switch anyway, but the framework will print a
warning about not being able to verify the voltage signal.
Implement card_busy function. Renesas host interface only exposes pins
DAT[0] and DAT[3] for reading the busy state, which is why only these
two pins are checked.
Signed-off-by: Mårten Lindahl <marten.lindahl@xxxxxxxx>
---
drivers/mmc/host/usdhi6rol0.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/drivers/mmc/host/usdhi6rol0.c b/drivers/mmc/host/usdhi6rol0.c
index b9b79b1089a0..e400a646e675 100644
--- a/drivers/mmc/host/usdhi6rol0.c
+++ b/drivers/mmc/host/usdhi6rol0.c
@@ -77,6 +77,7 @@
#define USDHI6_SD_INFO1_WP BIT(7)
#define USDHI6_SD_INFO1_D3_CARD_OUT BIT(8)
#define USDHI6_SD_INFO1_D3_CARD_IN BIT(9)
+#define USDHI6_SD_INFO1_SDDAT3 BIT(10)
#define USDHI6_SD_INFO2_CMD_ERR BIT(0)
#define USDHI6_SD_INFO2_CRC_ERR BIT(1)
@@ -1186,6 +1187,21 @@ static int usdhi6_sig_volt_switch(struct mmc_host *mmc, struct mmc_ios *ios)
return ret;
}
+static int usdhi6_card_busy(struct mmc_host *mmc)
+{
+ struct usdhi6_host *host = mmc_priv(mmc);
+ u32 info1 = usdhi6_read(host, USDHI6_SD_INFO1);
+ u32 info2 = usdhi6_read(host, USDHI6_SD_INFO2);
+
+ /* Check if the SD bus is processing a command */
+ if (!(info2 & USDHI6_SD_INFO2_SCLKDIVEN))
+ return 0;
+
+ /* Card is busy if it is pulling dat[0] & dat[3] low */
+ return !(info2 & USDHI6_SD_INFO2_SDDAT0 ||
+ info1 & USDHI6_SD_INFO1_SDDAT3);
+}
+
static const struct mmc_host_ops usdhi6_ops = {
.request = usdhi6_request,
.set_ios = usdhi6_set_ios,
@@ -1193,6 +1209,7 @@ static const struct mmc_host_ops usdhi6_ops = {
.get_ro = usdhi6_get_ro,
.enable_sdio_irq = usdhi6_enable_sdio_irq,
.start_signal_voltage_switch = usdhi6_sig_volt_switch,
+ .card_busy = usdhi6_card_busy,
};
/* State machine handlers */
--
2.20.1
