[U-Boot] [PATCH] pci: tegra: correctly program PADS_REFCLK registers

[Stephen Warren]

From: Stephen Warren <swarren at nvidia.com>

The value that should be programmed into the PADS_REFCLK register varies
per SoC. Fix the Tegra PCIe driver to program the correct values. Future
SoCs will require different values in cfg0/1, so the two values are stored
separately in the per-SoC data structures.

For reference, the values are all documented in NV bug 1771116 comment 20.
The Tegra210 value doesn't match the current TRM, but I've filed a bug to
get the TRM fixed. Earlier TRMs don't document the value this register
should contain, but the ASIC team has validated all these values, except
for the Tegra20 value which is simply left unchanged in this patch.

Signed-off-by: Stephen Warren <swarren at nvidia.com>
---
 drivers/pci/pci_tegra.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/pci/pci_tegra.c b/drivers/pci/pci_tegra.c
index c5b04daffa65..1aa56fc93739 100644
--- a/drivers/pci/pci_tegra.c
+++ b/drivers/pci/pci_tegra.c
@@ -154,15 +154,6 @@ DECLARE_GLOBAL_DATA_PTR;
 #define PADS_REFCLK_CFG_PREDI_SHIFT		8  /* 11:8 */
 #define PADS_REFCLK_CFG_DRVI_SHIFT		12 /* 15:12 */
 
-/* Default value provided by HW engineering is 0xfa5c */
-#define PADS_REFCLK_CFG_VALUE \
-	( \
-		(0x17 << PADS_REFCLK_CFG_TERM_SHIFT)   | \
-		(0    << PADS_REFCLK_CFG_E_TERM_SHIFT) | \
-		(0xa  << PADS_REFCLK_CFG_PREDI_SHIFT)  | \
-		(0xf  << PADS_REFCLK_CFG_DRVI_SHIFT)     \
-	)
-
 #define RP_VEND_XP	0x00000F00
 #define  RP_VEND_XP_DL_UP	(1 << 30)
 
@@ -198,6 +189,8 @@ struct tegra_pcie_soc {
 	unsigned int num_ports;
 	unsigned long pads_pll_ctl;
 	unsigned long tx_ref_sel;
+	u32 pads_refclk_cfg0;
+	u32 pads_refclk_cfg1;
 	bool has_pex_clkreq_en;
 	bool has_pex_bias_ctrl;
 	bool has_cml_clk;
@@ -628,11 +621,9 @@ static int tegra_pcie_phy_enable(struct tegra_pcie *pcie)
 	pads_writel(pcie, value, soc->pads_pll_ctl);
 
 	/* configure the reference clock driver */
-	value = PADS_REFCLK_CFG_VALUE | (PADS_REFCLK_CFG_VALUE << 16);
-	pads_writel(pcie, value, PADS_REFCLK_CFG0);
-
+	pads_writel(pcie, soc->pads_refclk_cfg0, PADS_REFCLK_CFG0);
 	if (soc->num_ports > 2)
-		pads_writel(pcie, PADS_REFCLK_CFG_VALUE, PADS_REFCLK_CFG1);
+		pads_writel(pcie, soc->pads_refclk_cfg1, PADS_REFCLK_CFG1);
 
 	/* wait for the PLL to lock */
 	err = tegra_pcie_pll_wait(pcie, 500);
@@ -943,6 +934,7 @@ static const struct tegra_pcie_soc pci_tegra_soc[] = {
 		.num_ports = 2,
 		.pads_pll_ctl = PADS_PLL_CTL_TEGRA20,
 		.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_DIV10,
+		.pads_refclk_cfg0 = 0xfa5cfa5c,
 		.has_pex_clkreq_en = false,
 		.has_pex_bias_ctrl = false,
 		.has_cml_clk = false,
@@ -952,6 +944,8 @@ static const struct tegra_pcie_soc pci_tegra_soc[] = {
 		.num_ports = 3,
 		.pads_pll_ctl = PADS_PLL_CTL_TEGRA30,
 		.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_BUF_EN,
+		.pads_refclk_cfg0 = 0xfa5cfa5c,
+		.pads_refclk_cfg1 = 0xfa5cfa5c,
 		.has_pex_clkreq_en = true,
 		.has_pex_bias_ctrl = true,
 		.has_cml_clk = true,
@@ -961,6 +955,7 @@ static const struct tegra_pcie_soc pci_tegra_soc[] = {
 		.num_ports = 2,
 		.pads_pll_ctl = PADS_PLL_CTL_TEGRA30,
 		.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_BUF_EN,
+		.pads_refclk_cfg0 = 0x44ac44ac,
 		.has_pex_clkreq_en = true,
 		.has_pex_bias_ctrl = true,
 		.has_cml_clk = true,
@@ -970,6 +965,7 @@ static const struct tegra_pcie_soc pci_tegra_soc[] = {
 		.num_ports = 2,
 		.pads_pll_ctl = PADS_PLL_CTL_TEGRA30,
 		.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_BUF_EN,
+		.pads_refclk_cfg0 = 0x90b890b8,
 		.has_pex_clkreq_en = true,
 		.has_pex_bias_ctrl = true,
 		.has_cml_clk = true,
-- 
2.9.0