[PATCH v4 3/6] ata: ahci_imx: AHB clock rate setting is not required on i.MX8QM AHCI SATA

[Richard Zhu <hongxing.zhu@xxxxxxx>]

i.MX8QM AHCI SATA doesn't need AHB clock rate to set the vendor
specified TIMER1MS register.
Do the AHB clock rate setting for i.MX53 and i.MX6Q AHCI SATA only.

Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
---
 drivers/ata/ahci_imx.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/ata/ahci_imx.c b/drivers/ata/ahci_imx.c
index 75258ed42d2ee..4dd98368f8562 100644
--- a/drivers/ata/ahci_imx.c
+++ b/drivers/ata/ahci_imx.c
@@ -872,12 +872,6 @@ static int imx_ahci_probe(struct platform_device *pdev)
 		return PTR_ERR(imxpriv->sata_ref_clk);
 	}
 
-	imxpriv->ahb_clk = devm_clk_get(dev, "ahb");
-	if (IS_ERR(imxpriv->ahb_clk)) {
-		dev_err(dev, "can't get ahb clock.\n");
-		return PTR_ERR(imxpriv->ahb_clk);
-	}
-
 	if (imxpriv->type == AHCI_IMX6Q || imxpriv->type == AHCI_IMX6QP) {
 		u32 reg_value;
 
@@ -937,11 +931,8 @@ static int imx_ahci_probe(struct platform_device *pdev)
 		goto disable_clk;
 
 	/*
-	 * Configure the HWINIT bits of the HOST_CAP and HOST_PORTS_IMPL,
-	 * and IP vendor specific register IMX_TIMER1MS.
-	 * Configure CAP_SSS (support stagered spin up).
-	 * Implement the port0.
-	 * Get the ahb clock rate, and configure the TIMER1MS register.
+	 * Configure the HWINIT bits of the HOST_CAP and HOST_PORTS_IMPL.
+	 * Set CAP_SSS (support stagered spin up) and Implement the port0.
 	 */
 	reg_val = readl(hpriv->mmio + HOST_CAP);
 	if (!(reg_val & HOST_CAP_SSS)) {
@@ -954,8 +945,19 @@ static int imx_ahci_probe(struct platform_device *pdev)
 		writel(reg_val, hpriv->mmio + HOST_PORTS_IMPL);
 	}
 
-	reg_val = clk_get_rate(imxpriv->ahb_clk) / 1000;
-	writel(reg_val, hpriv->mmio + IMX_TIMER1MS);
+	if (imxpriv->type != AHCI_IMX8QM) {
+		/*
+		 * Get AHB clock rate and configure the vendor specified
+		 * TIMER1MS register on i.MX53, i.MX6Q and i.MX6QP only.
+		 */
+		imxpriv->ahb_clk = devm_clk_get(dev, "ahb");
+		if (IS_ERR(imxpriv->ahb_clk)) {
+			dev_err(dev, "Failed to get ahb clock\n");
+			goto disable_sata;
+		}
+		reg_val = clk_get_rate(imxpriv->ahb_clk) / 1000;
+		writel(reg_val, hpriv->mmio + IMX_TIMER1MS);
+	}
 
 	ret = ahci_platform_init_host(pdev, hpriv, &ahci_imx_port_info,
 				      &ahci_platform_sht);
-- 
2.37.1