From: Stephen Warren <swarren@xxxxxxxxxx>
The registers PADS_REFCLK_CFG are an array of 16-bit data, one entry per
PCIe root port. For Tegra30, we therefore need to write a 3rd entry in
this array. Doing so mays the mini-PCIe slot on Beaver operate correctly.
While we're at it, add some #defines to partially document the fields
within these 16-bit values.
Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx>
---
This is for Thierry to squash into his Tegra PCIe driver staging branch.
drivers/pci/host/pci-tegra.c | 30 +++++++++++++++++++++++++-----
1 file changed, 25 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 2888307..cb069f5 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -195,6 +195,26 @@
#define PADS_REFCLK_CFG0 0x000000C8
#define PADS_REFCLK_CFG1 0x000000CC
+/*
+ * Fields in PADS_REFCLK_CFG*. Those registers form an array of 16-bit
+ * entries, one entry per PCIe port. These field definitions and desired
+ * values aren't in the TRM, but do come from NVIDIA.
+ */
+
+#define PADS_REFCLK_CFG_REFCLK2_TERM 2 /* 6:2 */
+#define PADS_REFCLK_CFG_REFCLK2_E_TERM 7
+#define PADS_REFCLK_CFG_REFCLK2_PREDI 8 /* 11:8 */
+#define PADS_REFCLK_CFG_REFCLK2_DRVI 12 /* 15:12 */
+
+/* 0xfa5c */
+#define PADS_REFCLK_CFG_VALUE \
+ ( \
+ (0x17 << PADS_REFCLK_CFG_REFCLK2_TERM) | \
+ (0 << PADS_REFCLK_CFG_REFCLK2_E_TERM) | \
+ (0xa << PADS_REFCLK_CFG_REFCLK2_PREDI) | \
+ (0xf << PADS_REFCLK_CFG_REFCLK2_DRVI) \
+ )
+
struct tegra_msi {
struct msi_chip chip;
DECLARE_BITMAP(used, INT_PCI_MSI_NR);
@@ -814,11 +834,11 @@ static int tegra_pcie_enable_controller(struct tegra_pcie *pcie)
value |= PADS_PLL_CTL_RST_B4SM;
pads_writel(pcie, value, soc->pads_pll_ctl);
- /*
- * Hack, set the clock voltage to the DEFAULT provided by hw folks.
- * This doesn't exist in the documentation.
- */
- pads_writel(pcie, 0xfa5cfa5c, PADS_REFCLK_CFG0);
+ /* Configure the reference clock driver */
+ pads_writel(pcie,
+ PADS_REFCLK_CFG_VALUE | (PADS_REFCLK_CFG_VALUE << 16),
+ PADS_REFCLK_CFG0);
+ pads_writel(pcie, PADS_REFCLK_CFG_VALUE, PADS_REFCLK_CFG1);
/* wait for the PLL to lock */
timeout = 300;
--
1.8.1.5
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