[PATCH v5 02/10] PCI: imx6: Add ref clock for i.MX95 PCIe

[Richard Zhu <hongxing.zhu@xxxxxxx>]

Add "ref" clock to enable reference clock. To avoid the DT
compatibility, i.MX95 REF clock might be optional. Replace the
devm_clk_bulk_get() by devm_clk_bulk_get_optional() to fetch
i.MX95 PCIe clocks in driver.

If use external clock, ref clock should point to external reference.

If use internal clock, CREF_EN in LAST_TO_REG controls reference output,
which implement in drivers/clk/imx/clk-imx95-blk-ctl.c.

Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
---
 drivers/pci/controller/dwc/pci-imx6.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 808d1f105417..73cb69ba8933 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -82,6 +82,7 @@ enum imx_pcie_variants {
 #define IMX_PCIE_FLAG_HAS_SERDES		BIT(6)
 #define IMX_PCIE_FLAG_SUPPORT_64BIT		BIT(7)
 #define IMX_PCIE_FLAG_CPU_ADDR_FIXUP		BIT(8)
+#define IMX_PCIE_FLAG_CLOCKS_OPTIONAL		BIT(9)
 
 #define imx_check_flag(pci, val)	(pci->drvdata->flags & val)
 
@@ -1330,7 +1331,12 @@ static int imx_pcie_probe(struct platform_device *pdev)
 		imx_pcie->clks[i].id = imx_pcie->drvdata->clk_names[i];
 
 	/* Fetch clocks */
-	ret = devm_clk_bulk_get(dev, imx_pcie->drvdata->clks_cnt, imx_pcie->clks);
+	if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_CLOCKS_OPTIONAL))
+		ret = devm_clk_bulk_get_optional(dev, imx_pcie->drvdata->clks_cnt,
+						 imx_pcie->clks);
+	else
+		ret = devm_clk_bulk_get(dev, imx_pcie->drvdata->clks_cnt,
+					imx_pcie->clks);
 	if (ret)
 		return ret;
 
@@ -1480,6 +1486,8 @@ static const char * const imx8mm_clks[] = {"pcie_bus", "pcie", "pcie_aux"};
 static const char * const imx8mq_clks[] = {"pcie_bus", "pcie", "pcie_phy", "pcie_aux"};
 static const char * const imx6sx_clks[] = {"pcie_bus", "pcie", "pcie_phy", "pcie_inbound_axi"};
 static const char * const imx8q_clks[] = {"mstr", "slv", "dbi"};
+static const char * const imx95_clks[] = {"pcie_bus", "pcie", "pcie_phy", "pcie_aux", "ref"};
+static const char * const imx95_ext_osc_clks[] = {"pcie_bus", "pcie", "pcie_phy", "pcie_aux"};
 
 static const struct imx_pcie_drvdata drvdata[] = {
 	[IMX6Q] = {
@@ -1592,9 +1600,10 @@ static const struct imx_pcie_drvdata drvdata[] = {
 	},
 	[IMX95] = {
 		.variant = IMX95,
-		.flags = IMX_PCIE_FLAG_HAS_SERDES,
-		.clk_names = imx8mq_clks,
-		.clks_cnt = ARRAY_SIZE(imx8mq_clks),
+		.flags = IMX_PCIE_FLAG_HAS_SERDES |
+			 IMX_PCIE_FLAG_CLOCKS_OPTIONAL,
+		.clk_names = imx95_clks,
+		.clks_cnt = ARRAY_SIZE(imx95_clks),
 		.ltssm_off = IMX95_PE0_GEN_CTRL_3,
 		.ltssm_mask = IMX95_PCIE_LTSSM_EN,
 		.mode_off[0]  = IMX95_PE0_GEN_CTRL_1,
-- 
2.37.1