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From:   Luo Jie <quic_luoj@quicinc.com>
To:     <agross@kernel.org>, <andersson@kernel.org>,
        <konrad.dybcio@linaro.org>, <davem@davemloft.net>,
        <edumazet@google.com>, <kuba@kernel.org>, <pabeni@redhat.com>,
        <robh+dt@kernel.org>, <krzysztof.kozlowski+dt@linaro.org>,
        <conor+dt@kernel.org>, <andrew@lunn.ch>, <hkallweit1@gmail.com>,
        <linux@armlinux.org.uk>, <robert.marko@sartura.hr>
CC:     <linux-arm-msm@vger.kernel.org>, <netdev@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <quic_srichara@quicinc.com>
Subject: [PATCH v3 3/5] net: mdio: ipq4019: configure CMN PLL clock for ipq5332
Date:   Thu, 14 Dec 2023 17:03:02 +0800
Message-ID: <20231214090304.16884-4-quic_luoj@quicinc.com>
In-Reply-To: <20231214090304.16884-1-quic_luoj@quicinc.com>
References: <20231214090304.16884-1-quic_luoj@quicinc.com>
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The reference clock of CMN PLL block is selectable, the internal
48MHZ is used by default.

The output clock of CMN PLL block is for providing the clock
source of ethernet device(such as qca8084), there are 1 * 25MHZ
and 3 * 50MHZ output clocks available for the ethernet devices.

Signed-off-by: Luo Jie <quic_luoj@quicinc.com>
---
 drivers/net/mdio/mdio-ipq4019.c | 137 +++++++++++++++++++++++++++++++-
 1 file changed, 136 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mdio/mdio-ipq4019.c b/drivers/net/mdio/mdio-ipq4019.c
index e24b0e688b10..3568ce7f48c6 100644
--- a/drivers/net/mdio/mdio-ipq4019.c
+++ b/drivers/net/mdio/mdio-ipq4019.c
@@ -44,6 +44,25 @@
 /* Maximum SOC PCS(uniphy) number on IPQ platform */
 #define ETH_LDO_RDY_CNT				3
 
+#define CMN_PLL_REFERENCE_SOURCE_SEL		0x28
+#define CMN_PLL_REFCLK_SOURCE_DIV		GENMASK(9, 8)
+
+#define CMN_PLL_REFERENCE_CLOCK			0x784
+#define CMN_PLL_REFCLK_EXTERNAL			BIT(9)
+#define CMN_PLL_REFCLK_DIV			GENMASK(8, 4)
+#define CMN_PLL_REFCLK_INDEX			GENMASK(3, 0)
+
+#define CMN_PLL_POWER_ON_AND_RESET		0x780
+#define CMN_ANA_EN_SW_RSTN			BIT(6)
+
+#define CMN_REFCLK_INTERNAL_48MHZ		0
+#define CMN_REFCLK_EXTERNAL_25MHZ		1
+#define CMN_REFCLK_EXTERNAL_31250KHZ		2
+#define CMN_REFCLK_EXTERNAL_40MHZ		3
+#define CMN_REFCLK_EXTERNAL_48MHZ		4
+#define CMN_REFCLK_EXTERNAL_50MHZ		5
+#define CMN_REFCLK_INTERNAL_96MHZ		6
+
 enum mdio_clk_id {
 	MDIO_CLK_MDIO_AHB,
 	MDIO_CLK_UNIPHY0_AHB,
@@ -55,6 +74,7 @@ enum mdio_clk_id {
 
 struct ipq4019_mdio_data {
 	void __iomem *membase;
+	void __iomem *cmn_membase;
 	void __iomem *eth_ldo_rdy[ETH_LDO_RDY_CNT];
 	struct clk *clk[MDIO_CLK_CNT];
 };
@@ -227,12 +247,116 @@ static int ipq4019_mdio_write_c22(struct mii_bus *bus, int mii_id, int regnum,
 	return 0;
 }
 
+/* For the CMN PLL block, the reference clock can be configured according to
+ * the device tree property "cmn-reference-clock", the internal 48MHZ is used
+ * by default on the ipq533 platform.
+ *
+ * The output clock of CMN PLL block is provided to the ethernet devices,
+ * threre are 4 CMN PLL output clocks (1*25MHZ + 3*50MHZ) enabled by default.
+ *
+ * Such as the output 50M clock for the qca8084 ethernet PHY.
+ */
+static int ipq_cmn_clock_config(struct mii_bus *bus)
+{
+	struct ipq4019_mdio_data *priv;
+	u32 reg_val, src_sel, ref_clk;
+	int ret;
+
+	priv = bus->priv;
+	if (priv->cmn_membase) {
+		reg_val = readl(priv->cmn_membase + CMN_PLL_REFERENCE_CLOCK);
+
+		/* Select reference clock source */
+		ret = of_property_read_u32(bus->parent->of_node,
+					   "cmn-reference-clock",
+					   &ref_clk);
+		if (!ret) {
+			switch (ref_clk) {
+			case CMN_REFCLK_INTERNAL_48MHZ:
+				reg_val &= ~(CMN_PLL_REFCLK_EXTERNAL |
+					     CMN_PLL_REFCLK_INDEX);
+				reg_val |= FIELD_PREP(CMN_PLL_REFCLK_INDEX, 7);
+				break;
+			case CMN_REFCLK_EXTERNAL_25MHZ:
+				reg_val &= ~(CMN_PLL_REFCLK_EXTERNAL |
+					     CMN_PLL_REFCLK_INDEX);
+				reg_val |= (CMN_PLL_REFCLK_EXTERNAL |
+					    FIELD_PREP(CMN_PLL_REFCLK_INDEX, 3));
+				break;
+			case CMN_REFCLK_EXTERNAL_31250KHZ:
+				reg_val &= ~(CMN_PLL_REFCLK_EXTERNAL |
+					     CMN_PLL_REFCLK_INDEX);
+				reg_val |= (CMN_PLL_REFCLK_EXTERNAL |
+					    FIELD_PREP(CMN_PLL_REFCLK_INDEX, 4));
+				break;
+			case CMN_REFCLK_EXTERNAL_40MHZ:
+				reg_val &= ~(CMN_PLL_REFCLK_EXTERNAL |
+					     CMN_PLL_REFCLK_INDEX);
+				reg_val |= (CMN_PLL_REFCLK_EXTERNAL |
+					    FIELD_PREP(CMN_PLL_REFCLK_INDEX, 6));
+				break;
+			case CMN_REFCLK_EXTERNAL_48MHZ:
+				reg_val &= ~(CMN_PLL_REFCLK_EXTERNAL |
+					     CMN_PLL_REFCLK_INDEX);
+				reg_val |= (CMN_PLL_REFCLK_EXTERNAL |
+					    FIELD_PREP(CMN_PLL_REFCLK_INDEX, 7));
+				break;
+			case CMN_REFCLK_EXTERNAL_50MHZ:
+				reg_val &= ~(CMN_PLL_REFCLK_EXTERNAL |
+					     CMN_PLL_REFCLK_INDEX);
+				reg_val |= (CMN_PLL_REFCLK_EXTERNAL |
+					    FIELD_PREP(CMN_PLL_REFCLK_INDEX, 8));
+				break;
+			case CMN_REFCLK_INTERNAL_96MHZ:
+				src_sel = readl(priv->cmn_membase +
+						CMN_PLL_REFERENCE_SOURCE_SEL);
+				src_sel &= ~CMN_PLL_REFCLK_SOURCE_DIV;
+				src_sel |= FIELD_PREP(CMN_PLL_REFCLK_SOURCE_DIV, 0);
+				writel(src_sel, priv->cmn_membase +
+				       CMN_PLL_REFERENCE_SOURCE_SEL);
+
+				reg_val &= ~CMN_PLL_REFCLK_DIV;
+				reg_val |= FIELD_PREP(CMN_PLL_REFCLK_DIV, 2);
+				break;
+			default:
+				return -EINVAL;
+			}
+		} else if (ret == -EINVAL) {
+			/* If the cmn-reference-clock is not specified,
+			 * the internal 48MHZ is selected by default.
+			 */
+			reg_val |= FIELD_PREP(CMN_PLL_REFCLK_INDEX, 7);
+		} else {
+			return ret;
+		}
+
+		writel(reg_val, priv->cmn_membase + CMN_PLL_REFERENCE_CLOCK);
+
+		/* assert CMN PLL */
+		reg_val = readl(priv->cmn_membase + CMN_PLL_POWER_ON_AND_RESET);
+		reg_val &= ~CMN_ANA_EN_SW_RSTN;
+		writel(reg_val, priv->cmn_membase);
+		fsleep(IPQ_PHY_SET_DELAY_US);
+
+		/* deassert CMN PLL */
+		reg_val |= CMN_ANA_EN_SW_RSTN;
+		writel(reg_val, priv->cmn_membase + CMN_PLL_POWER_ON_AND_RESET);
+		fsleep(IPQ_PHY_SET_DELAY_US);
+	}
+
+	return 0;
+}
+
 static int ipq_mdio_reset(struct mii_bus *bus)
 {
 	struct ipq4019_mdio_data *priv = bus->priv;
 	unsigned long rate;
 	int ret, index;
 
+	ret = ipq_cmn_clock_config(bus);
+	if (ret)
+		return ret;
+
 	/* For the platform ipq5332, there are two SoC uniphies available
 	 * for connecting with ethernet PHY, the SoC uniphy gcc clock
 	 * should be enabled for resetting the connected device such
@@ -296,7 +420,7 @@ static int ipq4019_mdio_probe(struct platform_device *pdev)
 	/* This resource are optional */
 	for (index = 0; index < ETH_LDO_RDY_CNT; index++) {
 		res = platform_get_resource(pdev, IORESOURCE_MEM, index + 1);
-		if (res) {
+		if (res && strcmp(res->name, "cmn_blk")) {
 			priv->eth_ldo_rdy[index] = devm_ioremap(&pdev->dev,
 								res->start,
 								resource_size(res));
@@ -317,6 +441,17 @@ static int ipq4019_mdio_probe(struct platform_device *pdev)
 		}
 	}
 
+	/* The CMN block resource is for providing clock source to ethernet,
+	 * which can be optionally configured on the platform ipq9574 and
+	 * ipq5332.
+	 */
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cmn_blk");
+	if (res) {
+		priv->cmn_membase = devm_ioremap_resource(&pdev->dev, res);
+		if (IS_ERR(priv->cmn_membase))
+			return PTR_ERR(priv->cmn_membase);
+	}
+
 	for (index = 0; index < MDIO_CLK_CNT; index++) {
 		priv->clk[index] = devm_clk_get_optional(&pdev->dev,
 							 mdio_clk_name[index]);
-- 
2.42.0