[net-next 1/2] dt-bindings: phy: Add `tx-p2p-microvolt` property binding

[net-next 1/2] dt-bindings: phy: Add `tx-p2p-microvolt` property binding

[Holger Brunck]

From: Marek Behún <kabel@kernel.org>

Common PHYs and network PCSes often have the possibility to specify
peak-to-peak voltage on the differential pair - the default voltage
sometimes needs to be changed for a particular board.

Add properties `tx-p2p-microvolt` and `tx-p2p-microvolt-names` for this
purpose. The second property is needed to specify the mode for the
corresponding voltage in the `tx-p2p-microvolt` property, if the voltage
is to be used only for speficic mode. More voltage-mode pairs can be
specified.

Example usage with only one voltage (it will be used for all supported
PHY modes, the `tx-p2p-microvolt-names` property is not needed in this
case):

  tx-p2p-microvolt = <915000>;

Example usage with voltages for multiple modes:

  tx-p2p-microvolt = <915000>, <1100000>, <1200000>;
  tx-p2p-microvolt-names = "2500base-x", "usb", "pcie";

Add these properties into a separate file phy/transmit-amplitude.yaml,
which should be referenced by any binding that uses it.

Signed-off-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/phy/transmit-amplitude.yaml           | 103 +++++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/phy/transmit-amplitude.yaml

diff --git a/Documentation/devicetree/bindings/phy/transmit-amplitude.yaml b/Documentation/devicetree/bindings/phy/transmit-amplitude.yaml
new file mode 100644
index 00000000..51492fe
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/transmit-amplitude.yaml
@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/transmit-amplitude.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common PHY and network PCS transmit amplitude property binding
+
+description:
+  Binding describing the peak-to-peak transmit amplitude for common PHYs
+  and network PCSes.
+
+maintainers:
+  - Marek Behún <kabel@kernel.org>
+
+properties:
+  tx-p2p-microvolt:
+    description:
+      Transmit amplitude voltages in microvolts, peak-to-peak. If this property
+      contains multiple values for various PHY modes, the
+      'tx-p2p-microvolt-names' property must be provided and contain
+      corresponding mode names.
+
+  tx-p2p-microvolt-names:
+    description: |
+      Names of the modes corresponding to voltages in the 'tx-p2p-microvolt'
+      property. Required only if multiple voltages are provided.
+
+      If a value of 'default' is provided, the system should use it for any PHY
+      mode that is otherwise not defined here. If 'default' is not provided, the
+      system should use manufacturer default value.
+    minItems: 1
+    maxItems: 16
+    items:
+      enum:
+        - default
+
+        # ethernet modes
+        - sgmii
+        - qsgmii
+        - xgmii
+        - 1000base-x
+        - 2500base-x
+        - 5gbase-r
+        - rxaui
+        - xaui
+        - 10gbase-kr
+        - usxgmii
+        - 10gbase-r
+        - 25gbase-r
+
+        # PCIe modes
+        - pcie
+        - pcie1
+        - pcie2
+        - pcie3
+        - pcie4
+        - pcie5
+        - pcie6
+
+        # USB modes
+        - usb
+        - usb-ls
+        - usb-fs
+        - usb-hs
+        - usb-ss
+        - usb-ss+
+        - usb-4
+
+        # storage modes
+        - sata
+        - ufs-hs
+        - ufs-hs-a
+        - ufs-hs-b
+
+        # display modes
+        - lvds
+        - dp
+        - dp-rbr
+        - dp-hbr
+        - dp-hbr2
+        - dp-hbr3
+        - dp-uhbr-10
+        - dp-uhbr-13.5
+        - dp-uhbr-20
+
+        # camera modes
+        - mipi-dphy
+        - mipi-dphy-univ
+        - mipi-dphy-v2.5-univ
+
+dependencies:
+  tx-p2p-microvolt-names: [ tx-p2p-microvolt ]
+
+additionalProperties: true
+
+examples:
+  - |
+    phy: phy {
+      #phy-cells = <1>;
+      tx-p2p-microvolt = <915000>, <1100000>, <1200000>;
+      tx-p2p-microvolt-names = "2500base-x", "usb-hs", "usb-ss";
+    };
-- 
1.8.3.1

[net-next 2/2] dsa: mv88e6xxx: make serdes SGMII/Fiber tx amplitude configurable

[Holger Brunck]

The mv88e6352, mv88e6240 and mv88e6176  have a serdes interface. This patch
allows to configure the output swing to a desired value in the
phy-handle of the port. The value which is peak to peak has to be
specified in microvolts. As the chips only supports eight dedicated
values we return EINVAL if the value in the DTS does not match one of
these values.

Signed-off-by: Holger Brunck <holger.brunck@hitachienergy.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Marek Behún <kabel@kernel.org>
---
 drivers/net/dsa/mv88e6xxx/chip.c   | 23 +++++++++++++++++++++++
 drivers/net/dsa/mv88e6xxx/chip.h   |  4 ++++
 drivers/net/dsa/mv88e6xxx/serdes.c | 38 ++++++++++++++++++++++++++++++++++++++
 drivers/net/dsa/mv88e6xxx/serdes.h |  5 +++++
 4 files changed, 70 insertions(+)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index c54649c..4dd5cef 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -2987,7 +2987,10 @@ static int mv88e6xxx_setup_upstream_port(struct mv88e6xxx_chip *chip, int port)
 
 static int mv88e6xxx_setup_port(struct mv88e6xxx_chip *chip, int port)
 {
+	struct device_node *phy_handle = NULL;
 	struct dsa_switch *ds = chip->ds;
+	struct dsa_port *dp;
+	int tx_amp;
 	int err;
 	u16 reg;
 
@@ -3178,6 +3181,23 @@ static int mv88e6xxx_setup_port(struct mv88e6xxx_chip *chip, int port)
 			return err;
 	}
 
+	if (chip->info->ops->serdes_set_tx_amplitude) {
+		dp = dsa_to_port(ds, port);
+		if (dp)
+			phy_handle = of_parse_phandle(dp->dn, "phy-handle", 0);
+
+		if (phy_handle && !of_property_read_u32(phy_handle,
+							"tx-p2p-microvolt",
+							&tx_amp))
+			err = chip->info->ops->serdes_set_tx_amplitude(chip,
+								port, tx_amp);
+		if (phy_handle) {
+			of_node_put(phy_handle);
+			if (err)
+				return err;
+		}
+	}
+
 	/* Port based VLAN map: give each port the same default address
 	 * database, and allow bidirectional communication between the
 	 * CPU and DSA port(s), and the other ports.
@@ -4241,6 +4261,7 @@ static int mv88e6xxx_set_eeprom(struct dsa_switch *ds,
 	.serdes_irq_status = mv88e6352_serdes_irq_status,
 	.serdes_get_regs_len = mv88e6352_serdes_get_regs_len,
 	.serdes_get_regs = mv88e6352_serdes_get_regs,
+	.serdes_set_tx_amplitude = mv88e6352_serdes_set_tx_amplitude,
 	.gpio_ops = &mv88e6352_gpio_ops,
 	.phylink_get_caps = mv88e6352_phylink_get_caps,
 };
@@ -4521,6 +4542,7 @@ static int mv88e6xxx_set_eeprom(struct dsa_switch *ds,
 	.serdes_irq_status = mv88e6352_serdes_irq_status,
 	.serdes_get_regs_len = mv88e6352_serdes_get_regs_len,
 	.serdes_get_regs = mv88e6352_serdes_get_regs,
+	.serdes_set_tx_amplitude = mv88e6352_serdes_set_tx_amplitude,
 	.gpio_ops = &mv88e6352_gpio_ops,
 	.avb_ops = &mv88e6352_avb_ops,
 	.ptp_ops = &mv88e6352_ptp_ops,
@@ -4927,6 +4949,7 @@ static int mv88e6xxx_set_eeprom(struct dsa_switch *ds,
 	.serdes_get_stats = mv88e6352_serdes_get_stats,
 	.serdes_get_regs_len = mv88e6352_serdes_get_regs_len,
 	.serdes_get_regs = mv88e6352_serdes_get_regs,
+	.serdes_set_tx_amplitude = mv88e6352_serdes_set_tx_amplitude,
 	.phylink_get_caps = mv88e6352_phylink_get_caps,
 };
 
diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
index 12aa637..30b92a2 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.h
+++ b/drivers/net/dsa/mv88e6xxx/chip.h
@@ -588,6 +588,10 @@ struct mv88e6xxx_ops {
 	void (*serdes_get_regs)(struct mv88e6xxx_chip *chip, int port,
 				void *_p);
 
+	/* SERDES SGMII/Fiber Output Amplitude */
+	int (*serdes_set_tx_amplitude)(struct mv88e6xxx_chip *chip, int port,
+				       int val);
+
 	/* Address Translation Unit operations */
 	int (*atu_get_hash)(struct mv88e6xxx_chip *chip, u8 *hash);
 	int (*atu_set_hash)(struct mv88e6xxx_chip *chip, u8 hash);
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index 6a177bf..7b37d45 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -1313,6 +1313,44 @@ void mv88e6390_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p)
 	}
 }
 
+static const int mv88e6352_serdes_p2p_to_reg[] = {
+	/* Index of value in microvolts corresponds to the register value */
+	14000, 112000, 210000, 308000, 406000, 504000, 602000, 700000,
+};
+
+int mv88e6352_serdes_set_tx_amplitude(struct mv88e6xxx_chip *chip, int port,
+				      int val)
+{
+	bool found = false;
+	u16 ctrl, reg;
+	int err;
+	int i;
+
+	err = mv88e6352_g2_scratch_port_has_serdes(chip, port);
+	if (err <= 0)
+		return err;
+
+	for (i = 0; i < ARRAY_SIZE(mv88e6352_serdes_p2p_to_reg); ++i) {
+		if (mv88e6352_serdes_p2p_to_reg[i] == val) {
+			reg = i;
+			found = true;
+			break;
+		}
+	}
+
+	if (!found)
+		return -EINVAL;
+
+	err = mv88e6352_serdes_read(chip, MV88E6352_SERDES_SPEC_CTRL2, &ctrl);
+	if (err)
+		return err;
+
+	ctrl &= ~MV88E6352_SERDES_OUT_AMP_MASK;
+	ctrl |= reg;
+
+	return mv88e6352_serdes_write(chip, MV88E6352_SERDES_SPEC_CTRL2, ctrl);
+}
+
 static int mv88e6393x_serdes_power_lane(struct mv88e6xxx_chip *chip, int lane,
 					bool on)
 {
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.h b/drivers/net/dsa/mv88e6xxx/serdes.h
index 8dd8ed2..29bb4e9 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.h
+++ b/drivers/net/dsa/mv88e6xxx/serdes.h
@@ -27,6 +27,8 @@
 #define MV88E6352_SERDES_INT_FIBRE_ENERGY	BIT(4)
 #define MV88E6352_SERDES_INT_STATUS	0x13
 
+#define MV88E6352_SERDES_SPEC_CTRL2	0x1a
+#define MV88E6352_SERDES_OUT_AMP_MASK		0x0007
 
 #define MV88E6341_PORT5_LANE		0x15
 
@@ -176,6 +178,9 @@ int mv88e6390_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
 int mv88e6390_serdes_get_regs_len(struct mv88e6xxx_chip *chip, int port);
 void mv88e6390_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p);
 
+int mv88e6352_serdes_set_tx_amplitude(struct mv88e6xxx_chip *chip, int port,
+				      int val);
+
 /* Return the (first) SERDES lane address a port is using, -errno otherwise. */
 static inline int mv88e6xxx_serdes_get_lane(struct mv88e6xxx_chip *chip,
 					    int port)
-- 
1.8.3.1

Re: [net-next 1/2] dt-bindings: phy: Add `tx-p2p-microvolt` property binding

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (master)
by David S. Miller <davem@davemloft.net>:

On Thu, 10 Feb 2022 18:48:22 +0100 you wrote:
> From: Marek Behún <kabel@kernel.org>
> 
> Common PHYs and network PCSes often have the possibility to specify
> peak-to-peak voltage on the differential pair - the default voltage
> sometimes needs to be changed for a particular board.
> 
> Add properties `tx-p2p-microvolt` and `tx-p2p-microvolt-names` for this
> purpose. The second property is needed to specify the mode for the
> corresponding voltage in the `tx-p2p-microvolt` property, if the voltage
> is to be used only for speficic mode. More voltage-mode pairs can be
> specified.
> 
> [...]

Here is the summary with links:
  - [net-next,1/2] dt-bindings: phy: Add `tx-p2p-microvolt` property binding
    https://git.kernel.org/netdev/net-next/c/066c4b6ba063
  - [net-next,2/2] dsa: mv88e6xxx: make serdes SGMII/Fiber tx amplitude configurable
    https://git.kernel.org/netdev/net-next/c/926eae604403

You are awesome, thank you!
-- 
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