[PATCH v1] clk: imx95-blk-ctl: Add func_out_en clock for i.MX9x PCIe

[Richard Zhu]

When internal PLL clock is used as PCIe REF clock, the BIT6(CREF_EN) and
BIT2(FUNC_OUTPUT_EN) control the PCIE_REF_OUT_CLK.

If the default value of BIT6(CREF_EN)&BIT2(FUNC_OUTPUT_EN) is 1b'1.
With the typical 100-ohm termination on the board, this results in
approximately 6mA of power consumption.

When PCIe internal PLL clock is not enabled, these two bits should
be cleared to 1b'0 to eliminate this power consumption.

Add a func_out_en clock for i.MX9x PCIe to serve as the parent gate clock
of the CREF_EN (BIT6) gate clock. Both of these two gate clocks enable
the output of the internal 100MHz differential reference clock.

Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
---
 drivers/clk/imx/clk-imx95-blk-ctl.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/imx/clk-imx95-blk-ctl.c b/drivers/clk/imx/clk-imx95-blk-ctl.c
index 56bed4471995..1f9259f45607 100644
--- a/drivers/clk/imx/clk-imx95-blk-ctl.c
+++ b/drivers/clk/imx/clk-imx95-blk-ctl.c
@@ -286,18 +286,28 @@ static const struct imx95_blk_ctl_dev_data netcmix_dev_data = {
 static const struct imx95_blk_ctl_clk_dev_data hsio_blk_ctl_clk_dev_data[] = {
 	[0] = {
 		.name = "hsio_blk_ctl_clk",
-		.parent_names = (const char *[]){ "hsio_pll", },
+		.parent_names = (const char *[]){ "func_out_en", },
 		.num_parents = 1,
 		.reg = 0,
 		.bit_idx = 6,
 		.bit_width = 1,
 		.type = CLK_GATE,
 		.flags = CLK_SET_RATE_PARENT,
+	},
+	[1] = {
+		.name = "func_out_en",
+		.parent_names = (const char *[]){ "hsio_pll", },
+		.num_parents = 1,
+		.reg = 0,
+		.bit_idx = 2,
+		.bit_width = 1,
+		.type = CLK_GATE,
+		.flags = CLK_SET_RATE_PARENT,
 	}
 };
 
 static const struct imx95_blk_ctl_dev_data hsio_blk_ctl_dev_data = {
-	.num_clks = 1,
+	.num_clks = ARRAY_SIZE(hsio_blk_ctl_clk_dev_data),
 	.clk_dev_data = hsio_blk_ctl_clk_dev_data,
 	.clk_reg_offset = 0,
 };
-- 
2.37.1