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From:   Renius Chen <reniuschengl@gmail.com>
To:     ulf.hansson@linaro.org, adrian.hunter@intel.com
Cc:     linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
        ben.chuang@genesyslogic.com.tw, greg.tu@genesyslogic.com.tw,
        Renius Chen <reniuschengl@gmail.com>
Subject: [PATCH] mmc: sdhci-pci-gli: Enable short circuit protection mechanism of GL9755
Date:   Thu, 25 Feb 2021 19:13:07 +0800
Message-Id: <20210225111307.62975-1-reniuschengl@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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Short circuit protection mechanism of GL9755 is disabled by HW default
setting. Enable short circuit protection to prevent GL9755 from being
damaged by short circuit or over current.

Signed-off-by: Renius Chen <reniuschengl@gmail.com>
---
 drivers/mmc/host/sdhci-pci-gli.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c
index 5606bdc08a96..7ba0fd601696 100644
--- a/drivers/mmc/host/sdhci-pci-gli.c
+++ b/drivers/mmc/host/sdhci-pci-gli.c
@@ -123,6 +123,9 @@
 #define PCI_GLI_9755_PLLSSC        0x68
 #define   PCI_GLI_9755_PLLSSC_PPM    GENMASK(15, 0)
 
+#define PCI_GLI_9755_SerDes  0x70
+#define PCI_GLI_9755_SCP_DIS   BIT(19)
+
 #define GLI_MAX_TUNING_LOOP 40
 
 /* Genesys Logic chipset */
@@ -547,6 +550,11 @@ static void gl9755_hw_setting(struct sdhci_pci_slot *slot)
 	value &= ~PCI_GLI_9755_DMACLK;
 	pci_write_config_dword(pdev, PCI_GLI_9755_PECONF, value);
 
+	/* enable short circuit protection */
+	pci_read_config_dword(pdev, PCI_GLI_9755_SerDes, &value);
+	value &= ~PCI_GLI_9755_SCP_DIS;
+	pci_write_config_dword(pdev, PCI_GLI_9755_SerDes, value);
+
 	gl9755_wt_off(pdev);
 }
 
-- 
2.27.0