[PATCH v3 2/2] net: mdio-ipq4019: add Clause 45 support

From: Robert Marko
Date: Fri Sep 18 2020 - 16:56:55 EST


While up-streaming the IPQ4019 driver it was thought that the controller had no Clause 45 support,
but it actually does and its activated by writing a bit to the mode register.

So lets add it as newer SoC-s use the same controller and Clause 45 compliant PHY-s.

Signed-off-by: Robert Marko <robert.marko@xxxxxxxxxx>
Cc: Luka Perkov <luka.perkov@xxxxxxxxxx>
---
Changes since v2:
* Fix missed reverse christmas tree

Changes since v1:
* Maintain reverse christmas tree

drivers/net/phy/mdio-ipq4019.c | 103 ++++++++++++++++++++++++++++-----
1 file changed, 89 insertions(+), 14 deletions(-)

diff --git a/drivers/net/phy/mdio-ipq4019.c b/drivers/net/phy/mdio-ipq4019.c
index 64b169e5a699..24fecbf659e8 100644
--- a/drivers/net/phy/mdio-ipq4019.c
+++ b/drivers/net/phy/mdio-ipq4019.c
@@ -12,6 +12,7 @@
#include <linux/phy.h>
#include <linux/platform_device.h>

+#define MDIO_MODE_REG 0x40
#define MDIO_ADDR_REG 0x44
#define MDIO_DATA_WRITE_REG 0x48
#define MDIO_DATA_READ_REG 0x4c
@@ -20,6 +21,12 @@
#define MDIO_CMD_ACCESS_START BIT(8)
#define MDIO_CMD_ACCESS_CODE_READ 0
#define MDIO_CMD_ACCESS_CODE_WRITE 1
+#define MDIO_CMD_ACCESS_CODE_C45_ADDR 0
+#define MDIO_CMD_ACCESS_CODE_C45_WRITE 1
+#define MDIO_CMD_ACCESS_CODE_C45_READ 2
+
+/* 0 = Clause 22, 1 = Clause 45 */
+#define MDIO_MODE_BIT BIT(8)

#define IPQ4019_MDIO_TIMEOUT 10000
#define IPQ4019_MDIO_SLEEP 10
@@ -41,19 +48,44 @@ static int ipq4019_mdio_wait_busy(struct mii_bus *bus)
static int ipq4019_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
{
struct ipq4019_mdio_data *priv = bus->priv;
+ unsigned int data;
unsigned int cmd;

- /* Reject clause 45 */
- if (regnum & MII_ADDR_C45)
- return -EOPNOTSUPP;
-
if (ipq4019_mdio_wait_busy(bus))
return -ETIMEDOUT;

- /* issue the phy address and reg */
- writel((mii_id << 8) | regnum, priv->membase + MDIO_ADDR_REG);
+ /* Clause 45 support */
+ if (regnum & MII_ADDR_C45) {
+ unsigned int mmd = (regnum >> 16) & 0x1F;
+ unsigned int reg = regnum & 0xFFFF;
+
+ /* Enter Clause 45 mode */
+ data = readl(priv->membase + MDIO_MODE_REG);
+
+ data |= MDIO_MODE_BIT;
+
+ writel(data, priv->membase + MDIO_MODE_REG);
+
+ /* issue the phy address and mmd */
+ writel((mii_id << 8) | mmd, priv->membase + MDIO_ADDR_REG);
+
+ /* issue reg */
+ writel(reg, priv->membase + MDIO_DATA_WRITE_REG);
+
+ cmd = MDIO_CMD_ACCESS_START | MDIO_CMD_ACCESS_CODE_C45_ADDR;
+ } else {
+ /* Enter Clause 22 mode */
+ data = readl(priv->membase + MDIO_MODE_REG);

- cmd = MDIO_CMD_ACCESS_START | MDIO_CMD_ACCESS_CODE_READ;
+ data &= ~MDIO_MODE_BIT;
+
+ writel(data, priv->membase + MDIO_MODE_REG);
+
+ /* issue the phy address and reg */
+ writel((mii_id << 8) | regnum, priv->membase + MDIO_ADDR_REG);
+
+ cmd = MDIO_CMD_ACCESS_START | MDIO_CMD_ACCESS_CODE_READ;
+ }

/* issue read command */
writel(cmd, priv->membase + MDIO_CMD_REG);
@@ -62,6 +94,15 @@ static int ipq4019_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
if (ipq4019_mdio_wait_busy(bus))
return -ETIMEDOUT;

+ if (regnum & MII_ADDR_C45) {
+ cmd = MDIO_CMD_ACCESS_START | MDIO_CMD_ACCESS_CODE_C45_READ;
+
+ writel(cmd, priv->membase + MDIO_CMD_REG);
+
+ if (ipq4019_mdio_wait_busy(bus))
+ return -ETIMEDOUT;
+ }
+
/* Read and return data */
return readl(priv->membase + MDIO_DATA_READ_REG);
}
@@ -70,23 +111,57 @@ static int ipq4019_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
u16 value)
{
struct ipq4019_mdio_data *priv = bus->priv;
+ unsigned int data;
unsigned int cmd;

- /* Reject clause 45 */
- if (regnum & MII_ADDR_C45)
- return -EOPNOTSUPP;
-
if (ipq4019_mdio_wait_busy(bus))
return -ETIMEDOUT;

- /* issue the phy address and reg */
- writel((mii_id << 8) | regnum, priv->membase + MDIO_ADDR_REG);
+ /* Clause 45 support */
+ if (regnum & MII_ADDR_C45) {
+ unsigned int mmd = (regnum >> 16) & 0x1F;
+ unsigned int reg = regnum & 0xFFFF;
+
+ /* Enter Clause 45 mode */
+ data = readl(priv->membase + MDIO_MODE_REG);
+
+ data |= MDIO_MODE_BIT;
+
+ writel(data, priv->membase + MDIO_MODE_REG);
+
+ /* issue the phy address and mmd */
+ writel((mii_id << 8) | mmd, priv->membase + MDIO_ADDR_REG);
+
+ /* issue reg */
+ writel(reg, priv->membase + MDIO_DATA_WRITE_REG);
+
+ cmd = MDIO_CMD_ACCESS_START | MDIO_CMD_ACCESS_CODE_C45_ADDR;
+
+ writel(cmd, priv->membase + MDIO_CMD_REG);
+
+ if (ipq4019_mdio_wait_busy(bus))
+ return -ETIMEDOUT;
+ } else {
+ /* Enter Clause 22 mode */
+ data = readl(priv->membase + MDIO_MODE_REG);
+
+ data &= ~MDIO_MODE_BIT;
+
+ writel(data, priv->membase + MDIO_MODE_REG);
+
+ /* issue the phy address and reg */
+ writel((mii_id << 8) | regnum, priv->membase + MDIO_ADDR_REG);
+ }

/* issue write data */
writel(value, priv->membase + MDIO_DATA_WRITE_REG);

- cmd = MDIO_CMD_ACCESS_START | MDIO_CMD_ACCESS_CODE_WRITE;
/* issue write command */
+ if (regnum & MII_ADDR_C45)
+ cmd = MDIO_CMD_ACCESS_START | MDIO_CMD_ACCESS_CODE_C45_WRITE;
+ else
+ cmd = MDIO_CMD_ACCESS_START | MDIO_CMD_ACCESS_CODE_WRITE;
+
writel(cmd, priv->membase + MDIO_CMD_REG);

/* Wait write complete */
--
2.26.2