net: phy: Add LED mode driver for Microsemi PHYs.

LED Mode:
Microsemi PHY support 2 LEDs (LED[0] and LED[1]) to display different
status information that can be selected by setting LED mode.

LED Mode parameter (vsc8531, led-0-mode) and (vsc8531, led-1-mode) get
from Device Tree.

Signed-off-by: Raju Lakkaraju <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

Documentation/devicetree/bindings/net/mscc-phy-vsc8531.txt

···
 			  'vddmac'.
 			  Default value is 0%.
 			  Ref: Table:1 - Edge rate change (below).
+- vsc8531,led-0-mode	: LED mode. Specify how the LED[0] should behave.
+			  Allowed values are define in
+			  "include/dt-bindings/net/mscc-phy-vsc8531.h".
+			  Default value is VSC8531_LINK_1000_ACTIVITY (1).
+- vsc8531,led-1-mode	: LED mode. Specify how the LED[1] should behave.
+			  Allowed values are define in
+			  "include/dt-bindings/net/mscc-phy-vsc8531.h".
+			  Default value is VSC8531_LINK_100_ACTIVITY (2).
 
 Table: 1 - Edge rate change
 ----------------------------------------------------------------|
···
                 compatible = "ethernet-phy-id0007.0570";
                 vsc8531,vddmac		= <3300>;
                 vsc8531,edge-slowdown	= <7>;
+                vsc8531,led-0-mode	= <LINK_1000_ACTIVITY>;
+                vsc8531,led-1-mode	= <LINK_100_ACTIVITY>;
         };

drivers/net/phy/mscc.c

···
 #include <linux/phy.h>
 #include <linux/of.h>
 #include <linux/netdevice.h>
+#include <dt-bindings/net/mscc-phy-vsc8531.h>
 
 enum rgmii_rx_clock_delay {
 	RGMII_RX_CLK_DELAY_0_2_NS = 0,
···
 
 #define MSCC_PHY_DEV_AUX_CNTL		  28
 #define HP_AUTO_MDIX_X_OVER_IND_MASK	  0x2000
+
+#define MSCC_PHY_LED_MODE_SEL		  29
+#define LED_1_MODE_SEL_MASK		  0x00F0
+#define LED_0_MODE_SEL_MASK		  0x000F
+#define LED_1_MODE_SEL_POS		  4
 
 #define MSCC_EXT_PAGE_ACCESS		  31
 #define MSCC_PHY_PAGE_STANDARD		  0x0000 /* Standard registers */
···
 
 struct vsc8531_private {
 	int rate_magic;
+	u8 led_0_mode;
+	u8 led_1_mode;
 };
 
 #ifdef CONFIG_OF_MDIO
···
 	int rc;
 
 	rc = phy_write(phydev, MSCC_EXT_PAGE_ACCESS, page);
+	return rc;
+}
+
+static int vsc85xx_led_cntl_set(struct phy_device *phydev,
+				u8 led_num,
+				u8 mode)
+{
+	int rc;
+	u16 reg_val;
+
+	mutex_lock(&phydev->lock);
+	reg_val = phy_read(phydev, MSCC_PHY_LED_MODE_SEL);
+	if (led_num) {
+		reg_val &= ~LED_1_MODE_SEL_MASK;
+		reg_val |= (((u16)mode << LED_1_MODE_SEL_POS) &
+			    LED_1_MODE_SEL_MASK);
+	} else {
+		reg_val &= ~LED_0_MODE_SEL_MASK;
+		reg_val |= ((u16)mode & LED_0_MODE_SEL_MASK);
+	}
+	rc = phy_write(phydev, MSCC_PHY_LED_MODE_SEL, reg_val);
+	mutex_unlock(&phydev->lock);
+
 	return rc;
 }
 
···
 
 	return -EINVAL;
 }
+
+static int vsc85xx_dt_led_mode_get(struct phy_device *phydev,
+				   char *led,
+				   u8 default_mode)
+{
+	struct device *dev = &phydev->mdio.dev;
+	struct device_node *of_node = dev->of_node;
+	u8 led_mode;
+	int err;
+
+	if (!of_node)
+		return -ENODEV;
+
+	led_mode = default_mode;
+	err = of_property_read_u8(of_node, led, &led_mode);
+	if (!err && (led_mode > 15 || led_mode == 7 || led_mode == 11)) {
+		phydev_err(phydev, "DT %s invalid\n", led);
+		return -EINVAL;
+	}
+
+	return led_mode;
+}
+
 #else
 static int vsc85xx_edge_rate_magic_get(struct phy_device *phydev)
 {
 	return 0;
+}
+
+static int vsc85xx_dt_led_mode_get(struct phy_device *phydev,
+				   char *led,
+				   u8 default_mode)
+{
+	return default_mode;
 }
 #endif /* CONFIG_OF_MDIO */
 
···
 	if (rc)
 		return rc;
 
+	rc = vsc85xx_led_cntl_set(phydev, 1, vsc8531->led_1_mode);
+	if (rc)
+		return rc;
+
+	rc = vsc85xx_led_cntl_set(phydev, 0, vsc8531->led_0_mode);
+	if (rc)
+		return rc;
+
 	rc = genphy_config_init(phydev);
 
 	return rc;
···
 
 static int vsc85xx_probe(struct phy_device *phydev)
 {
-	int rate_magic;
 	struct vsc8531_private *vsc8531;
+	int rate_magic;
+	int led_mode;
 
 	rate_magic = vsc85xx_edge_rate_magic_get(phydev);
 	if (rate_magic < 0)
···
 	phydev->priv = vsc8531;
 
 	vsc8531->rate_magic = rate_magic;
+
+	/* LED[0] and LED[1] mode */
+	led_mode = vsc85xx_dt_led_mode_get(phydev, "vsc8531,led-0-mode",
+					   VSC8531_LINK_1000_ACTIVITY);
+	if (led_mode < 0)
+		return led_mode;
+	vsc8531->led_0_mode = led_mode;
+
+	led_mode = vsc85xx_dt_led_mode_get(phydev, "vsc8531,led-1-mode",
+					   VSC8531_LINK_100_ACTIVITY);
+	if (led_mode < 0)
+		return led_mode;
+	vsc8531->led_1_mode = led_mode;
 
 	return 0;
 }

include/dt-bindings/net/mscc-phy-vsc8531.h

···
+/*
+ * Device Tree constants for Microsemi VSC8531 PHY
+ *
+ * Author: Nagaraju Lakkaraju
+ *
+ * License: Dual MIT/GPL
+ * Copyright (c) 2017 Microsemi Corporation
+ */
+
+#ifndef _DT_BINDINGS_MSCC_VSC8531_H
+#define _DT_BINDINGS_MSCC_VSC8531_H
+
+/* PHY LED Modes */
+#define VSC8531_LINK_ACTIVITY           0
+#define VSC8531_LINK_1000_ACTIVITY      1
+#define VSC8531_LINK_100_ACTIVITY       2
+#define VSC8531_LINK_10_ACTIVITY        3
+#define VSC8531_LINK_100_1000_ACTIVITY  4
+#define VSC8531_LINK_10_1000_ACTIVITY   5
+#define VSC8531_LINK_10_100_ACTIVITY    6
+#define VSC8531_DUPLEX_COLLISION        8
+#define VSC8531_COLLISION               9
+#define VSC8531_ACTIVITY                10
+#define VSC8531_AUTONEG_FAULT           12
+#define VSC8531_SERIAL_MODE             13
+#define VSC8531_FORCE_LED_OFF           14
+#define VSC8531_FORCE_LED_ON            15
+
+#endif