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Subject[PATCH] sdhci: Specific quirk vor VIA SDHCI controller in VX855ES
The SDHCI controller found in the VX855ES requires 10ms
delay between applying power and applying clock.

This issue has been discovered and documented by the OLPC XO1.5 team.

Signed-off-by: Harald Welte <HaraldWelte@viatech.com>
---
drivers/mmc/host/sdhci-pci.c | 20 ++++++++++++++++++++
drivers/mmc/host/sdhci.c | 7 +++++++
drivers/mmc/host/sdhci.h | 2 ++
3 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index 65be279..2f15cc1 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.c
@@ -284,6 +284,18 @@ static const struct sdhci_pci_fixes sdhci_jmicron = {
.resume = jmicron_resume,
};

+static int via_probe(struct sdhci_pci_chip *chip)
+{
+ if (chip->pdev->revision == 0x10)
+ chip->quirks |= SDHCI_QUIRK_DELAY_AFTER_POWER;
+
+ return 0;
+}
+
+static const struct sdhci_pci_fixes sdhci_via = {
+ .probe = via_probe,
+};
+
static const struct pci_device_id pci_ids[] __devinitdata = {
{
.vendor = PCI_VENDOR_ID_RICOH,
@@ -349,6 +361,14 @@ static const struct pci_device_id pci_ids[] __devinitdata = {
.driver_data = (kernel_ulong_t)&sdhci_jmicron,
},

+ {
+ .vendor = PCI_VENDOR_ID_VIA,
+ .device = 0x95d0,
+ .subvendor = PCI_ANY_ID,
+ .subdevice = PCI_ANY_ID,
+ .driver_data = (kernel_ulong_t)&sdhci_via,
+ },
+
{ /* Generic SD host controller */
PCI_DEVICE_CLASS((PCI_CLASS_SYSTEM_SDHCI << 8), 0xFFFF00)
},
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 35789c6..62e2a63 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1057,6 +1057,13 @@ static void sdhci_set_power(struct sdhci_host *host, unsigned short power)
pwr |= SDHCI_POWER_ON;

sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
+
+ /*
+ * Some controllers need an extra 10ms delay of 10ms before they
+ * can apply clock after applying power
+ */
+ if ((host->quirks & SDHCI_QUIRK_DELAY_AFTER_POWER))
+ mdelay(10);
}

/*****************************************************************************\
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 2de0834..9832a5f 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -226,6 +226,8 @@ struct sdhci_host {
#define SDHCI_QUIRK_RESTORE_IRQS_AFTER_RESET (1<<19)
/* Controller has to be forced to use block size of 2048 bytes */
#define SDHCI_QUIRK_FORCE_BLK_SZ_2048 (1<<20)
+/* Controller needs 10ms delay between applying power and clock */
+#define SDHCI_QUIRK_DELAY_AFTER_POWER (1<<21)

int irq; /* Device IRQ */
void __iomem * ioaddr; /* Mapped address */
--
1.6.3.1

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