diff mbox series

mmc: sdhci-pci-gli: Disable slow mode in HS400 mode for GL9763E

Message ID 20201125100004.1288-1-benchuanggli@gmail.com
State New
Headers show
Series mmc: sdhci-pci-gli: Disable slow mode in HS400 mode for GL9763E | expand

Commit Message

Ben Chuang Nov. 25, 2020, 10 a.m. UTC 
From: Ben Chuang <ben.chuang@genesyslogic.com.tw>

The GL9763E uses 150Mhz (slow mode) by default in HS400 mode. In order
to make HS400 mode run at 200Mhz, the slow mode needs to be turned off.

Fixes: 1ae1d2d6e555 ("mmc: sdhci-pci-gli: Add Genesys Logic GL9763E support")
Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
---
 drivers/mmc/host/sdhci-pci-gli.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Ben Chuang Nov. 25, 2020, 10:55 a.m. UTC | #1 
Hi Ulf,

On Wed, Nov 25, 2020 at 6:49 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> On Wed, 25 Nov 2020 at 11:43, Ben Chuang <benchuanggli@gmail.com> wrote:
> >
> > Hi Ulf,
> >
> > On Wed, Nov 25, 2020 at 6:04 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
> > >
> > > On Wed, 25 Nov 2020 at 10:59, Ben Chuang <benchuanggli@gmail.com> wrote:
> > > >
> > > > From: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> > > >
> > > > The GL9763E uses 150Mhz (slow mode) by default in HS400 mode. In order
> > > > to make HS400 mode run at 200Mhz, the slow mode needs to be turned off.
> > > >
> > > > Fixes: 1ae1d2d6e555 ("mmc: sdhci-pci-gli: Add Genesys Logic GL9763E support")
> > >
> > > Why a fixes tag? This patch looks like an improvement and not a fix, right?
> > >
> >
> > Since the specification defines that the HS400 mode must run at 200Mhz,
> > this patch fixes the HS400 mode to 200Mhz.
>
> The spec states that in HS400 mode the clock can be *up to 200MHz* -
> not that it must run at 200MHz. At least at those places I have looked
> at in the spec.
>

You are right. I will resend v2.

Best regards,
Ben

> [...]
>
> Kind regards
> Uffe
diff mbox series

Patch

diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c
index 9887485a4134..d45d7e529150 100644
--- a/drivers/mmc/host/sdhci-pci-gli.c
+++ b/drivers/mmc/host/sdhci-pci-gli.c
@@ -87,6 +87,9 @@ 
 #define PCIE_GLI_9763E_SCR	 0x8E0
 #define   GLI_9763E_SCR_AXI_REQ	   BIT(9)
 
+#define PCIE_GLI_9763E_MMC_CTRL  0x960
+#define   GLI_9763E_HS400_SLOW     BIT(3)
+
 #define SDHCI_GLI_9763E_CQE_BASE_ADDR	 0x200
 #define GLI_9763E_CQE_TRNS_MODE	   (SDHCI_TRNS_MULTI | \
 				    SDHCI_TRNS_BLK_CNT_EN | \
@@ -764,6 +767,10 @@  static void gli_set_gl9763e(struct sdhci_pci_slot *slot)
 	value |= GLI_9763E_SCR_AXI_REQ;
 	pci_write_config_dword(pdev, PCIE_GLI_9763E_SCR, value);
 
+	pci_read_config_dword(pdev, PCIE_GLI_9763E_MMC_CTRL, &value);
+	value &= ~GLI_9763E_HS400_SLOW;
+	pci_write_config_dword(pdev, PCIE_GLI_9763E_MMC_CTRL, value);
+
 	pci_read_config_dword(pdev, PCIE_GLI_9763E_VHS, &value);
 	value &= ~GLI_9763E_VHS_REV;
 	value |= FIELD_PREP(GLI_9763E_VHS_REV, GLI_9763E_VHS_REV_R);