[PATCH v1 1/2] net: mdio: Add the reset function for IPQ MDIO driver

Luo Jie
2021-08-08T07:21:57Z

1. configure the MDIO clock source frequency.
2. the LDO resource is needed to indicate the ethernet LDO ready for CMN_PLL.

Signed-off-by: Luo Jie <luoj@codeaurora.org>
---
drivers/net/mdio/Kconfig | 1 +
drivers/net/mdio/mdio-ipq4019.c | 47 +++++++++++++++++++++++++++++++++
2 files changed, 48 insertions(+)

diff --git a/drivers/net/mdio/Kconfig b/drivers/net/mdio/Kconfig
index 99a6c13a11af..a94d34cc7dc1 100644
--- a/drivers/net/mdio/Kconfig
+++ b/drivers/net/mdio/Kconfig
@@ -169,6 +169,7 @@ config MDIO_OCTEON
config MDIO_IPQ4019
tristate "Qualcomm IPQ4019 MDIO interface support"
depends on HAS_IOMEM && OF_MDIO
+ depends on COMMON_CLK
help
This driver supports the MDIO interface found in Qualcomm
IPQ40xx series Soc-s.
diff --git a/drivers/net/mdio/mdio-ipq4019.c b/drivers/net/mdio/mdio-ipq4019.c
index 9cd71d896963..b365f13c92ca 100644
--- a/drivers/net/mdio/mdio-ipq4019.c
+++ b/drivers/net/mdio/mdio-ipq4019.c
@@ -11,6 +11,7 @@
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
+#include <linux/clk.h>

#define MDIO_MODE_REG 0x40
#define MDIO_ADDR_REG 0x44
@@ -31,8 +32,15 @@
#define IPQ4019_MDIO_TIMEOUT 10000
#define IPQ4019_MDIO_SLEEP 10

+/* MDIO clock source frequency is fixed to 100M */
+#define IPQ_MDIO_CLK_RATE 100000000
+
+#define IPQ_PHY_SET_DELAY_US 100000
+
struct ipq4019_mdio_data {
void __iomem *membase;
+ void __iomem *eth_ldo_rdy;
+ struct clk *mdio_clk;
};

static int ipq4019_mdio_wait_busy(struct mii_bus *bus)
@@ -171,10 +179,41 @@ static int ipq4019_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
return 0;
}

+static int ipq_mdio_reset(struct mii_bus *bus)
+{
+ struct ipq4019_mdio_data *priv = bus->priv;
+ u32 val;
+ int ret;
+
+ /* To indicate CMN_PLL that ethernet_ldo has been ready if platform resource 1
+ * is specified in the device tree.
+ * */
+ if (!IS_ERR(priv->eth_ldo_rdy)) {
+ val = readl(priv->eth_ldo_rdy);
+ val |= BIT(0);
+ writel(val, priv->eth_ldo_rdy);
+ fsleep(IPQ_PHY_SET_DELAY_US);
+ }
+
+ /* Configure MDIO clock source frequency if clock is specified in the device tree */
+ if (!IS_ERR_OR_NULL(priv->mdio_clk)) {
+ ret = clk_set_rate(priv->mdio_clk, IPQ_MDIO_CLK_RATE);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(priv->mdio_clk);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
static int ipq4019_mdio_probe(struct platform_device *pdev)
{
struct ipq4019_mdio_data *priv;
struct mii_bus *bus;
+ struct resource *res;
int ret;

bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*priv));
@@ -182,14 +221,22 @@ static int ipq4019_mdio_probe(struct platform_device *pdev)
return -ENOMEM;

priv = bus->priv;
+ priv->eth_ldo_rdy = IOMEM_ERR_PTR(-EINVAL);

priv->membase = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->membase))
return PTR_ERR(priv->membase);

+ priv->mdio_clk = devm_clk_get_optional(&pdev->dev, "gcc_mdio_ahb_clk");
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ if (res)
+ priv->eth_ldo_rdy = devm_ioremap_resource(&pdev->dev, res);
+
bus->name = "ipq4019_mdio";
bus->read = ipq4019_mdio_read;
bus->write = ipq4019_mdio_write;
+ bus->reset = ipq_mdio_reset;
bus->parent = &pdev->dev;
snprintf(bus->id, MII_BUS_ID_SIZE, "%s%d", pdev->name, pdev->id);

--
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