clk: imx7ulp: Make sure earlycon's clock is enabled

Earlycon's clock could be disabled during kernel boot up,
if earlycon is enabled and its clock is gated, then kernel
boot up will fail. Make sure earlycon's clock is enabled
during kernel boot up.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

drivers/clk/imx/clk-imx7ulp.c

@@ -42,6 +42,19 @@ static const struct clk_div_table ulp_div_table[] = {
 	{ .val = 7, .div = 64, },
 };
 
+static const int pcc2_uart_clk_ids[] __initconst = {
+	IMX7ULP_CLK_LPUART4,
+	IMX7ULP_CLK_LPUART5,
+};
+
+static const int pcc3_uart_clk_ids[] __initconst = {
+	IMX7ULP_CLK_LPUART6,
+	IMX7ULP_CLK_LPUART7,
+};
+
+static struct clk **pcc2_uart_clks[ARRAY_SIZE(pcc2_uart_clk_ids) + 1] __initdata;
+static struct clk **pcc3_uart_clks[ARRAY_SIZE(pcc3_uart_clk_ids) + 1] __initdata;
+
 static void __init imx7ulp_clk_scg1_init(struct device_node *np)
 {
 	struct clk_hw_onecell_data *clk_data;
@@ -135,6 +148,7 @@ static void __init imx7ulp_clk_pcc2_init(struct device_node *np)
 	struct clk_hw_onecell_data *clk_data;
 	struct clk_hw **clks;
 	void __iomem *base;
+	int i;
 
 	clk_data = kzalloc(struct_size(clk_data, hws, IMX7ULP_CLK_PCC2_END),
 			   GFP_KERNEL);
@@ -173,6 +187,14 @@ static void __init imx7ulp_clk_pcc2_init(struct device_node *np)
 	imx_check_clk_hws(clks, clk_data->num);
 
 	of_clk_add_hw_provider(np, of_clk_hw_onecell_get, clk_data);
+
+	for (i = 0; i < ARRAY_SIZE(pcc2_uart_clk_ids); i++) {
+		int index = pcc2_uart_clk_ids[i];
+
+		pcc2_uart_clks[i] = &clks[index]->clk;
+	}
+
+	imx_register_uart_clocks(pcc2_uart_clks);
 }
 CLK_OF_DECLARE(imx7ulp_clk_pcc2, "fsl,imx7ulp-pcc2", imx7ulp_clk_pcc2_init);
 
@@ -181,6 +203,7 @@ static void __init imx7ulp_clk_pcc3_init(struct device_node *np)
 	struct clk_hw_onecell_data *clk_data;
 	struct clk_hw **clks;
 	void __iomem *base;
+	int i;
 
 	clk_data = kzalloc(struct_size(clk_data, hws, IMX7ULP_CLK_PCC3_END),
 			   GFP_KERNEL);
@@ -218,6 +241,14 @@ static void __init imx7ulp_clk_pcc3_init(struct device_node *np)
 	imx_check_clk_hws(clks, clk_data->num);
 
 	of_clk_add_hw_provider(np, of_clk_hw_onecell_get, clk_data);
+
+	for (i = 0; i < ARRAY_SIZE(pcc3_uart_clk_ids); i++) {
+		int index = pcc3_uart_clk_ids[i];
+
+		pcc3_uart_clks[i] = &clks[index]->clk;
+	}
+
+	imx_register_uart_clocks(pcc3_uart_clks);
 }
 CLK_OF_DECLARE(imx7ulp_clk_pcc3, "fsl,imx7ulp-pcc3", imx7ulp_clk_pcc3_init);