[PATCH v4 01/14] mci: atmel_mci: disable power save mode

[Ahmad Fatoum]

Power saving mode will clock down the MCI clock according to the value
of the PWSDIV (Power Saving Divider) field of the mode register.

No where in Linux or barebox do we set a value for PWSDIV however, so
the safe thing to do is disabling power saving mode.

This aligns barebox with what AT91Bootstrap and the U-Boot driver are
doing and fixes SD-Card block write failures when using barebox as first
stage bootloader on the AT91SAM9263.

Without this change, writing the environment would fail in barebox,
an ext4 fsck in Linux would hang and barebox PBL chainloading of barebox
proper would hang when CONFIG_DEBUG_PBL is disabled.

Fixes: 6cf02124b10d ("mci: add Atmel AT91 MCI driver")
Reviewed-by: Sam Ravnborg <sam at ravnborg.org>
Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 drivers/mci/atmel_mci.c     | 1 +
 drivers/mci/atmel_mci_pbl.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/mci/atmel_mci.c b/drivers/mci/atmel_mci.c
index 431331ddc310..9021dba0f89b 100644
--- a/drivers/mci/atmel_mci.c
+++ b/drivers/mci/atmel_mci.c
@@ -151,6 +151,7 @@ static int atmci_probe(struct device *hw_dev)
 
 	clk_enable(host->clk);
 	atmci_writel(host, ATMCI_CR, ATMCI_CR_SWRST);
+	atmci_writel(host, ATMCI_CR, ATMCI_CR_PWSDIS);
 	atmci_writel(host, ATMCI_IDR, ~0UL);
 	host->bus_hz = clk_get_rate(host->clk);
 	clk_disable(host->clk);
diff --git a/drivers/mci/atmel_mci_pbl.c b/drivers/mci/atmel_mci_pbl.c
index 7483e9375f1d..bd4faa4de5f0 100644
--- a/drivers/mci/atmel_mci_pbl.c
+++ b/drivers/mci/atmel_mci_pbl.c
@@ -106,6 +106,7 @@ int at91_mci_bio_init(struct pbl_bio *bio, void __iomem *base,
 	else
 		host->sdc_reg = ATMCI_SDCSEL_SLOT_A;
 
+	atmci_writel(host, ATMCI_CR, ATMCI_CR_PWSDIS);
 	atmci_writel(host, ATMCI_DTOR, 0x7f);
 
 	atmci_common_set_ios(host, &ios);
-- 
2.39.2