[RFC net-next v3 1/3] net: dsa: microchip: ksz8: move BMCR specific code to separate function

From: Oleksij Rempel
Date: Fri Jan 12 2024 - 09:08:26 EST


Isolate the Basic Mode Control Register (BMCR) operations in the ksz8795
driver by moving the BMCR-related code segments from the ksz8_r_phy()
and ksz8_w_phy() functions to newly created ksz8_r_phy_bmcr() and
ksz8_w_phy_bmcr() functions.

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Reviewed-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Acked-by: Arun Ramadoss <arun.ramadoss@xxxxxxxxxxxxx>
---
drivers/net/dsa/microchip/ksz8795.c | 366 ++++++++++++++++++----------
1 file changed, 240 insertions(+), 126 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 61b71bcfe396..1269dde832bd 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -676,59 +676,118 @@ static int ksz8_r_phy_ctrl(struct ksz_device *dev, int port, u16 *val)
return 0;
}

+/**
+ * ksz8_r_phy_bmcr - Translates and reads from the SMI interface to a MIIM PHY
+ * Basic mode control register (Reg. 0).
+ * @dev: The KSZ device instance.
+ * @port: The port number to be read.
+ * @val: The value read from the SMI interface.
+ *
+ * This function reads the SMI interface and translates the hardware register
+ * bit values into their corresponding control settings for a MIIM PHY Basic
+ * mode control register.
+ *
+ * MIIM Bit Mapping Comparison between KSZ8794 and KSZ8873
+ * -------------------------------------------------------------------
+ * MIIM Bit | KSZ8794 Reg/Bit | KSZ8873 Reg/Bit
+ * ----------------------------+-----------------------------+----------------
+ * Bit 15 - Soft Reset | 0xF/4 | Not supported
+ * Bit 14 - Loopback | 0xD/0 (MAC), 0xF/7 (PHY) ~ 0xD/0 (PHY)
+ * Bit 13 - Force 100 | 0xC/6 = 0xC/6
+ * Bit 12 - AN Enable | 0xC/7 (reverse logic) ~ 0xC/7
+ * Bit 11 - Power Down | 0xD/3 = 0xD/3
+ * Bit 10 - PHY Isolate | 0xF/5 | Not supported
+ * Bit 9 - Restart AN | 0xD/5 = 0xD/5
+ * Bit 8 - Force Full-Duplex | 0xC/5 = 0xC/5
+ * Bit 7 - Collision Test/Res. | Not supported | Not supported
+ * Bit 6 - Reserved | Not supported | Not supported
+ * Bit 5 - Hp_mdix | 0x9/7 ~ 0xF/7
+ * Bit 4 - Force MDI | 0xD/1 = 0xD/1
+ * Bit 3 - Disable MDIX | 0xD/2 = 0xD/2
+ * Bit 2 - Disable Far-End F. | ???? | 0xD/4
+ * Bit 1 - Disable Transmit | 0xD/6 = 0xD/6
+ * Bit 0 - Disable LED | 0xD/7 = 0xD/7
+ * -------------------------------------------------------------------
+ *
+ * Return: 0 on success, error code on failure.
+ */
+static int ksz8_r_phy_bmcr(struct ksz_device *dev, u16 port, u16 *val)
+{
+ const u16 *regs = dev->info->regs;
+ u8 restart, speed, ctrl;
+ int ret;
+
+ *val = 0;
+
+ ret = ksz_pread8(dev, port, regs[P_NEG_RESTART_CTRL], &restart);
+ if (ret)
+ return ret;
+
+ ret = ksz_pread8(dev, port, regs[P_SPEED_STATUS], &speed);
+ if (ret)
+ return ret;
+
+ ret = ksz_pread8(dev, port, regs[P_FORCE_CTRL], &ctrl);
+ if (ret)
+ return ret;
+
+ if (restart & PORT_PHY_LOOPBACK)
+ *val |= BMCR_LOOPBACK;
+
+ if (ctrl & PORT_FORCE_100_MBIT)
+ *val |= BMCR_SPEED100;
+
+ if (ksz_is_ksz88x3(dev)) {
+ if ((ctrl & PORT_AUTO_NEG_ENABLE))
+ *val |= BMCR_ANENABLE;
+ } else {
+ if (!(ctrl & PORT_AUTO_NEG_DISABLE))
+ *val |= BMCR_ANENABLE;
+ }
+
+ if (restart & PORT_POWER_DOWN)
+ *val |= BMCR_PDOWN;
+
+ if (restart & PORT_AUTO_NEG_RESTART)
+ *val |= BMCR_ANRESTART;
+
+ if (ctrl & PORT_FORCE_FULL_DUPLEX)
+ *val |= BMCR_FULLDPLX;
+
+ if (speed & PORT_HP_MDIX)
+ *val |= KSZ886X_BMCR_HP_MDIX;
+
+ if (restart & PORT_FORCE_MDIX)
+ *val |= KSZ886X_BMCR_FORCE_MDI;
+
+ if (restart & PORT_AUTO_MDIX_DISABLE)
+ *val |= KSZ886X_BMCR_DISABLE_AUTO_MDIX;
+
+ if (restart & PORT_TX_DISABLE)
+ *val |= KSZ886X_BMCR_DISABLE_TRANSMIT;
+
+ if (restart & PORT_LED_OFF)
+ *val |= KSZ886X_BMCR_DISABLE_LED;
+
+ return 0;
+}
+
int ksz8_r_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 *val)
{
- u8 restart, speed, ctrl, link;
+ u8 ctrl, link, val1, val2;
int processed = true;
const u16 *regs;
- u8 val1, val2;
u16 data = 0;
- u8 p = phy;
+ u16 p = phy;
int ret;

regs = dev->info->regs;

switch (reg) {
case MII_BMCR:
- ret = ksz_pread8(dev, p, regs[P_NEG_RESTART_CTRL], &restart);
+ ret = ksz8_r_phy_bmcr(dev, p, &data);
if (ret)
return ret;
-
- ret = ksz_pread8(dev, p, regs[P_SPEED_STATUS], &speed);
- if (ret)
- return ret;
-
- ret = ksz_pread8(dev, p, regs[P_FORCE_CTRL], &ctrl);
- if (ret)
- return ret;
-
- if (restart & PORT_PHY_LOOPBACK)
- data |= BMCR_LOOPBACK;
- if (ctrl & PORT_FORCE_100_MBIT)
- data |= BMCR_SPEED100;
- if (ksz_is_ksz88x3(dev)) {
- if ((ctrl & PORT_AUTO_NEG_ENABLE))
- data |= BMCR_ANENABLE;
- } else {
- if (!(ctrl & PORT_AUTO_NEG_DISABLE))
- data |= BMCR_ANENABLE;
- }
- if (restart & PORT_POWER_DOWN)
- data |= BMCR_PDOWN;
- if (restart & PORT_AUTO_NEG_RESTART)
- data |= BMCR_ANRESTART;
- if (ctrl & PORT_FORCE_FULL_DUPLEX)
- data |= BMCR_FULLDPLX;
- if (speed & PORT_HP_MDIX)
- data |= KSZ886X_BMCR_HP_MDIX;
- if (restart & PORT_FORCE_MDIX)
- data |= KSZ886X_BMCR_FORCE_MDI;
- if (restart & PORT_AUTO_MDIX_DISABLE)
- data |= KSZ886X_BMCR_DISABLE_AUTO_MDIX;
- if (restart & PORT_TX_DISABLE)
- data |= KSZ886X_BMCR_DISABLE_TRANSMIT;
- if (restart & PORT_LED_OFF)
- data |= KSZ886X_BMCR_DISABLE_LED;
break;
case MII_BMSR:
ret = ksz_pread8(dev, p, regs[P_LINK_STATUS], &link);
@@ -860,113 +919,168 @@ static int ksz8_w_phy_ctrl(struct ksz_device *dev, int port, u16 val)
return ret;
}

-int ksz8_w_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 val)
+/**
+ * ksz8_w_phy_bmcr - Translates and writes to the SMI interface from a MIIM PHY
+ * Basic mode control register (Reg. 0).
+ * @dev: The KSZ device instance.
+ * @port: The port number to be configured.
+ * @val: The register value to be written.
+ *
+ * This function translates control settings from a MIIM PHY Basic mode control
+ * register into their corresponding hardware register bit values for the SMI
+ * interface.
+ *
+ * MIIM Bit Mapping Comparison between KSZ8794 and KSZ8873
+ * -------------------------------------------------------------------
+ * MIIM Bit | KSZ8794 Reg/Bit | KSZ8873 Reg/Bit
+ * ----------------------------+-----------------------------+----------------
+ * Bit 15 - Soft Reset | 0xF/4 | Not supported
+ * Bit 14 - Loopback | 0xD/0 (MAC), 0xF/7 (PHY) ~ 0xD/0 (PHY)
+ * Bit 13 - Force 100 | 0xC/6 = 0xC/6
+ * Bit 12 - AN Enable | 0xC/7 (reverse logic) ~ 0xC/7
+ * Bit 11 - Power Down | 0xD/3 = 0xD/3
+ * Bit 10 - PHY Isolate | 0xF/5 | Not supported
+ * Bit 9 - Restart AN | 0xD/5 = 0xD/5
+ * Bit 8 - Force Full-Duplex | 0xC/5 = 0xC/5
+ * Bit 7 - Collision Test/Res. | Not supported | Not supported
+ * Bit 6 - Reserved | Not supported | Not supported
+ * Bit 5 - Hp_mdix | 0x9/7 ~ 0xF/7
+ * Bit 4 - Force MDI | 0xD/1 = 0xD/1
+ * Bit 3 - Disable MDIX | 0xD/2 = 0xD/2
+ * Bit 2 - Disable Far-End F. | ???? | 0xD/4
+ * Bit 1 - Disable Transmit | 0xD/6 = 0xD/6
+ * Bit 0 - Disable LED | 0xD/7 = 0xD/7
+ * -------------------------------------------------------------------
+ *
+ * Return: 0 on success, error code on failure.
+ */
+static int ksz8_w_phy_bmcr(struct ksz_device *dev, u16 port, u16 val)
{
- u8 restart, speed, ctrl, data;
- const u16 *regs;
- u8 p = phy;
+ const u16 *regs = dev->info->regs;
+ u8 restart, ctrl, speed, data;
int ret;

- regs = dev->info->regs;
+ /* Do not support PHY reset function. */
+ if (val & BMCR_RESET)
+ return 0;

- switch (reg) {
- case MII_BMCR:
+ ret = ksz_pread8(dev, port, regs[P_SPEED_STATUS], &speed);
+ if (ret)
+ return ret;

- /* Do not support PHY reset function. */
- if (val & BMCR_RESET)
- break;
- ret = ksz_pread8(dev, p, regs[P_SPEED_STATUS], &speed);
+ data = speed;
+ if (val & KSZ886X_BMCR_HP_MDIX)
+ data |= PORT_HP_MDIX;
+ else
+ data &= ~PORT_HP_MDIX;
+
+ if (data != speed) {
+ ret = ksz_pwrite8(dev, port, regs[P_SPEED_STATUS], data);
if (ret)
return ret;
+ }
+
+ ret = ksz_pread8(dev, port, regs[P_FORCE_CTRL], &ctrl);
+ if (ret)
+ return ret;

- data = speed;
- if (val & KSZ886X_BMCR_HP_MDIX)
- data |= PORT_HP_MDIX;
+ data = ctrl;
+ if (ksz_is_ksz88x3(dev)) {
+ if ((val & BMCR_ANENABLE))
+ data |= PORT_AUTO_NEG_ENABLE;
+ else
+ data &= ~PORT_AUTO_NEG_ENABLE;
+ } else {
+ if (!(val & BMCR_ANENABLE))
+ data |= PORT_AUTO_NEG_DISABLE;
else
- data &= ~PORT_HP_MDIX;
+ data &= ~PORT_AUTO_NEG_DISABLE;

- if (data != speed) {
- ret = ksz_pwrite8(dev, p, regs[P_SPEED_STATUS], data);
- if (ret)
- return ret;
- }
+ /* Fiber port does not support auto-negotiation. */
+ if (dev->ports[port].fiber)
+ data |= PORT_AUTO_NEG_DISABLE;
+ }
+
+ if (val & BMCR_SPEED100)
+ data |= PORT_FORCE_100_MBIT;
+ else
+ data &= ~PORT_FORCE_100_MBIT;
+
+ if (val & BMCR_FULLDPLX)
+ data |= PORT_FORCE_FULL_DUPLEX;
+ else
+ data &= ~PORT_FORCE_FULL_DUPLEX;

- ret = ksz_pread8(dev, p, regs[P_FORCE_CTRL], &ctrl);
+ if (data != ctrl) {
+ ret = ksz_pwrite8(dev, port, regs[P_FORCE_CTRL], data);
if (ret)
return ret;
+ }

- data = ctrl;
- if (ksz_is_ksz88x3(dev)) {
- if ((val & BMCR_ANENABLE))
- data |= PORT_AUTO_NEG_ENABLE;
- else
- data &= ~PORT_AUTO_NEG_ENABLE;
- } else {
- if (!(val & BMCR_ANENABLE))
- data |= PORT_AUTO_NEG_DISABLE;
- else
- data &= ~PORT_AUTO_NEG_DISABLE;
-
- /* Fiber port does not support auto-negotiation. */
- if (dev->ports[p].fiber)
- data |= PORT_AUTO_NEG_DISABLE;
- }
+ ret = ksz_pread8(dev, port, regs[P_NEG_RESTART_CTRL], &restart);
+ if (ret)
+ return ret;

- if (val & BMCR_SPEED100)
- data |= PORT_FORCE_100_MBIT;
- else
- data &= ~PORT_FORCE_100_MBIT;
- if (val & BMCR_FULLDPLX)
- data |= PORT_FORCE_FULL_DUPLEX;
- else
- data &= ~PORT_FORCE_FULL_DUPLEX;
+ data = restart;
+ if (val & KSZ886X_BMCR_DISABLE_LED)
+ data |= PORT_LED_OFF;
+ else
+ data &= ~PORT_LED_OFF;

- if (data != ctrl) {
- ret = ksz_pwrite8(dev, p, regs[P_FORCE_CTRL], data);
- if (ret)
- return ret;
- }
+ if (val & KSZ886X_BMCR_DISABLE_TRANSMIT)
+ data |= PORT_TX_DISABLE;
+ else
+ data &= ~PORT_TX_DISABLE;

- ret = ksz_pread8(dev, p, regs[P_NEG_RESTART_CTRL], &restart);
+ if (val & BMCR_ANRESTART)
+ data |= PORT_AUTO_NEG_RESTART;
+ else
+ data &= ~(PORT_AUTO_NEG_RESTART);
+
+ if (val & BMCR_PDOWN)
+ data |= PORT_POWER_DOWN;
+ else
+ data &= ~PORT_POWER_DOWN;
+
+ if (val & KSZ886X_BMCR_DISABLE_AUTO_MDIX)
+ data |= PORT_AUTO_MDIX_DISABLE;
+ else
+ data &= ~PORT_AUTO_MDIX_DISABLE;
+
+ if (val & KSZ886X_BMCR_FORCE_MDI)
+ data |= PORT_FORCE_MDIX;
+ else
+ data &= ~PORT_FORCE_MDIX;
+
+ if (val & BMCR_LOOPBACK)
+ data |= PORT_PHY_LOOPBACK;
+ else
+ data &= ~PORT_PHY_LOOPBACK;
+
+ if (data != restart) {
+ ret = ksz_pwrite8(dev, port, regs[P_NEG_RESTART_CTRL],
+ data);
if (ret)
return ret;
+ }

- data = restart;
- if (val & KSZ886X_BMCR_DISABLE_LED)
- data |= PORT_LED_OFF;
- else
- data &= ~PORT_LED_OFF;
- if (val & KSZ886X_BMCR_DISABLE_TRANSMIT)
- data |= PORT_TX_DISABLE;
- else
- data &= ~PORT_TX_DISABLE;
- if (val & BMCR_ANRESTART)
- data |= PORT_AUTO_NEG_RESTART;
- else
- data &= ~(PORT_AUTO_NEG_RESTART);
- if (val & BMCR_PDOWN)
- data |= PORT_POWER_DOWN;
- else
- data &= ~PORT_POWER_DOWN;
- if (val & KSZ886X_BMCR_DISABLE_AUTO_MDIX)
- data |= PORT_AUTO_MDIX_DISABLE;
- else
- data &= ~PORT_AUTO_MDIX_DISABLE;
- if (val & KSZ886X_BMCR_FORCE_MDI)
- data |= PORT_FORCE_MDIX;
- else
- data &= ~PORT_FORCE_MDIX;
- if (val & BMCR_LOOPBACK)
- data |= PORT_PHY_LOOPBACK;
- else
- data &= ~PORT_PHY_LOOPBACK;
+ return 0;
+}

- if (data != restart) {
- ret = ksz_pwrite8(dev, p, regs[P_NEG_RESTART_CTRL],
- data);
- if (ret)
- return ret;
- }
+int ksz8_w_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 val)
+{
+ const u16 *regs;
+ u8 ctrl, data;
+ u16 p = phy;
+ int ret;
+
+ regs = dev->info->regs;
+
+ switch (reg) {
+ case MII_BMCR:
+ ret = ksz8_w_phy_bmcr(dev, p, val);
+ if (ret)
+ return ret;
break;
case MII_ADVERTISE:
ret = ksz_pread8(dev, p, regs[P_LOCAL_CTRL], &ctrl);
--
2.39.2