net: sxgbe: add EEE(Energy Efficient Ethernet) for Samsung sxgbe

Added support for the EEE(Energy Efficient Ethernet) in 10G ethernet driver.

Signed-off-by: Girish K S <ks.giri@samsung.com>
Neatening-by: Joe Perches <joe@perches.com>
Signed-off-by: Byungho An <bh74.an@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/samsung/sxgbe/sxgbe_common.h

@@ -118,6 +118,33 @@ struct sxgbe_mtl_ops;
 #define RX_PTP_SIGNAL		0x0A
 #define RX_PTP_RESV_MSG		0x0F
 
+/* EEE-LPI mode  flags*/
+#define TX_ENTRY_LPI_MODE	0x10
+#define TX_EXIT_LPI_MODE	0x20
+#define RX_ENTRY_LPI_MODE	0x40
+#define RX_EXIT_LPI_MODE	0x80
+
+/* EEE-LPI Interrupt status flag */
+#define LPI_INT_STATUS		BIT(5)
+
+/* EEE-LPI Default timer values */
+#define LPI_LINK_STATUS_TIMER	0x3E8
+#define LPI_MAC_WAIT_TIMER	0x00
+
+/* EEE-LPI Control and status definitions */
+#define LPI_CTRL_STATUS_TXA	BIT(19)
+#define LPI_CTRL_STATUS_PLSDIS	BIT(18)
+#define LPI_CTRL_STATUS_PLS	BIT(17)
+#define LPI_CTRL_STATUS_LPIEN	BIT(16)
+#define LPI_CTRL_STATUS_TXRSTP	BIT(11)
+#define LPI_CTRL_STATUS_RXRSTP	BIT(10)
+#define LPI_CTRL_STATUS_RLPIST	BIT(9)
+#define LPI_CTRL_STATUS_TLPIST	BIT(8)
+#define LPI_CTRL_STATUS_RLPIEX	BIT(3)
+#define LPI_CTRL_STATUS_RLPIEN	BIT(2)
+#define LPI_CTRL_STATUS_TLPIEX	BIT(1)
+#define LPI_CTRL_STATUS_TLPIEN	BIT(0)
+
 enum dma_irq_status {
 	tx_hard_error	= BIT(0),
 	tx_bump_tc	= BIT(1),
@@ -202,6 +229,13 @@ struct sxgbe_extra_stats {
 	unsigned long rx_buffer_access_err;
 	unsigned long rx_data_transfer_err;
 
+	/* EEE-LPI stats */
+	unsigned long tx_lpi_entry_n;
+	unsigned long tx_lpi_exit_n;
+	unsigned long rx_lpi_entry_n;
+	unsigned long rx_lpi_exit_n;
+	unsigned long eee_wakeup_error_n;
+
 	/* RX specific */
 	/* L2 error */
 	unsigned long rx_code_gmii_err;
@@ -299,6 +333,13 @@ struct sxgbe_core_ops {
 				       unsigned char feature_index);
 	/* adjust SXGBE speed */
 	void (*set_speed)(void __iomem *ioaddr, unsigned char speed);
+
+	/* EEE-LPI specific operations */
+	void (*set_eee_mode)(void __iomem *ioaddr);
+	void (*reset_eee_mode)(void __iomem *ioaddr);
+	void (*set_eee_timer)(void __iomem *ioaddr, const int ls,
+			      const int tw);
+	void (*set_eee_pls)(void __iomem *ioaddr, const int link);
 };
 
 const struct sxgbe_core_ops *sxgbe_get_core_ops(void);
@@ -354,6 +395,8 @@ struct sxgbe_hw_features {
 	/* IEEE 1588-2008 */
 	unsigned int atime_stamp;
 
+	unsigned int eee;
+
 	unsigned int tx_csum_offload;
 	unsigned int rx_csum_offload;
 	unsigned int multi_macaddr;
@@ -437,6 +480,13 @@ struct sxgbe_priv_data {
 	/* tc control */
 	int tx_tc;
 	int rx_tc;
+	/* EEE-LPI specific members */
+	struct timer_list eee_ctrl_timer;
+	bool tx_path_in_lpi_mode;
+	int lpi_irq;
+	int eee_enabled;
+	int eee_active;
+	int tx_lpi_timer;
 };
 
 /* Function prototypes */
@@ -459,4 +509,7 @@ int sxgbe_restore(struct net_device *ndev);
 
 const struct sxgbe_mtl_ops *sxgbe_get_mtl_ops(void);
 
+void sxgbe_disable_eee_mode(struct sxgbe_priv_data * const priv);
+bool sxgbe_eee_init(struct sxgbe_priv_data * const priv);
+
 #endif /* __SXGBE_COMMON_H__ */

drivers/net/ethernet/samsung/sxgbe/sxgbe_core.c

@@ -48,11 +48,38 @@ static void sxgbe_core_dump_regs(void __iomem *ioaddr)
 {
 }
 
+static int sxgbe_get_lpi_status(void __iomem *ioaddr, const u32 irq_status)
+{
+	int status = 0;
+	int lpi_status;
+
+	/* Reading this register shall clear all the LPI status bits */
+	lpi_status = readl(ioaddr + SXGBE_CORE_LPI_CTRL_STATUS);
+
+	if (lpi_status & LPI_CTRL_STATUS_TLPIEN)
+		status |= TX_ENTRY_LPI_MODE;
+	if (lpi_status & LPI_CTRL_STATUS_TLPIEX)
+		status |= TX_EXIT_LPI_MODE;
+	if (lpi_status & LPI_CTRL_STATUS_RLPIEN)
+		status |= RX_ENTRY_LPI_MODE;
+	if (lpi_status & LPI_CTRL_STATUS_RLPIEX)
+		status |= RX_EXIT_LPI_MODE;
+
+	return status;
+}
+
 /* Handle extra events on specific interrupts hw dependent */
 static int sxgbe_core_host_irq_status(void __iomem *ioaddr,
 				      struct sxgbe_extra_stats *x)
 {
-	return 0;
+	int irq_status, status = 0;
+
+	irq_status = readl(ioaddr + SXGBE_CORE_INT_STATUS_REG);
+
+	if (unlikely(irq_status & LPI_INT_STATUS))
+		status |= sxgbe_get_lpi_status(ioaddr, irq_status);
+
+	return status;
 }
 
 /* Set power management mode (e.g. magic frame) */
@@ -138,6 +165,59 @@ static void sxgbe_core_set_speed(void __iomem *ioaddr, unsigned char speed)
 	writel(tx_cfg, ioaddr + SXGBE_CORE_TX_CONFIG_REG);
 }
 
+static void  sxgbe_set_eee_mode(void __iomem *ioaddr)
+{
+	u32 ctrl;
+
+	/* Enable the LPI mode for transmit path with Tx automate bit set.
+	 * When Tx Automate bit is set, MAC internally handles the entry
+	 * to LPI mode after all outstanding and pending packets are
+	 * transmitted.
+	 */
+	ctrl = readl(ioaddr + SXGBE_CORE_LPI_CTRL_STATUS);
+	ctrl |= LPI_CTRL_STATUS_LPIEN | LPI_CTRL_STATUS_TXA;
+	writel(ctrl, ioaddr + SXGBE_CORE_LPI_CTRL_STATUS);
+}
+
+static void  sxgbe_reset_eee_mode(void __iomem *ioaddr)
+{
+	u32 ctrl;
+
+	ctrl = readl(ioaddr + SXGBE_CORE_LPI_CTRL_STATUS);
+	ctrl &= ~(LPI_CTRL_STATUS_LPIEN | LPI_CTRL_STATUS_TXA);
+	writel(ctrl, ioaddr + SXGBE_CORE_LPI_CTRL_STATUS);
+}
+
+static void  sxgbe_set_eee_pls(void __iomem *ioaddr, const int link)
+{
+	u32 ctrl;
+
+	ctrl = readl(ioaddr + SXGBE_CORE_LPI_CTRL_STATUS);
+
+	/* If the PHY link status is UP then set PLS */
+	if (link)
+		ctrl |= LPI_CTRL_STATUS_PLS;
+	else
+		ctrl &= ~LPI_CTRL_STATUS_PLS;
+
+	writel(ctrl, ioaddr + SXGBE_CORE_LPI_CTRL_STATUS);
+}
+
+static void  sxgbe_set_eee_timer(void __iomem *ioaddr,
+				 const int ls, const int tw)
+{
+	int value = ((tw & 0xffff)) | ((ls & 0x7ff) << 16);
+
+	/* Program the timers in the LPI timer control register:
+	 * LS: minimum time (ms) for which the link
+	 *  status from PHY should be ok before transmitting
+	 *  the LPI pattern.
+	 * TW: minimum time (us) for which the core waits
+	 *  after it has stopped transmitting the LPI pattern.
+	 */
+	writel(value, ioaddr + SXGBE_CORE_LPI_TIMER_CTRL);
+}
+
 const struct sxgbe_core_ops core_ops = {
 	.core_init		= sxgbe_core_init,
 	.dump_regs		= sxgbe_core_dump_regs,
@@ -150,6 +230,10 @@ const struct sxgbe_core_ops core_ops = {
 	.get_controller_version	= sxgbe_get_controller_version,
 	.get_hw_feature		= sxgbe_get_hw_feature,
 	.set_speed		= sxgbe_core_set_speed,
+	.set_eee_mode		= sxgbe_set_eee_mode,
+	.reset_eee_mode		= sxgbe_reset_eee_mode,
+	.set_eee_timer		= sxgbe_set_eee_timer,
+	.set_eee_pls		= sxgbe_set_eee_pls,
 };
 
 const struct sxgbe_core_ops *sxgbe_get_core_ops(void)

drivers/net/ethernet/samsung/sxgbe/sxgbe_ethtool.c

@@ -32,10 +32,57 @@ struct sxgbe_stats {
 }
 
 static const struct sxgbe_stats sxgbe_gstrings_stats[] = {
+	SXGBE_STAT(tx_lpi_entry_n),
+	SXGBE_STAT(tx_lpi_exit_n),
+	SXGBE_STAT(rx_lpi_entry_n),
+	SXGBE_STAT(rx_lpi_exit_n),
+	SXGBE_STAT(eee_wakeup_error_n),
 };
 #define SXGBE_STATS_LEN ARRAY_SIZE(sxgbe_gstrings_stats)
 
+static int sxgbe_get_eee(struct net_device *dev,
+			 struct ethtool_eee *edata)
+{
+	struct sxgbe_priv_data *priv = netdev_priv(dev);
+
+	if (!priv->hw_cap.eee)
+		return -EOPNOTSUPP;
+
+	edata->eee_enabled = priv->eee_enabled;
+	edata->eee_active = priv->eee_active;
+	edata->tx_lpi_timer = priv->tx_lpi_timer;
+
+	return phy_ethtool_get_eee(priv->phydev, edata);
+}
+
+static int sxgbe_set_eee(struct net_device *dev,
+			 struct ethtool_eee *edata)
+{
+	struct sxgbe_priv_data *priv = netdev_priv(dev);
+
+	priv->eee_enabled = edata->eee_enabled;
+
+	if (!priv->eee_enabled) {
+		sxgbe_disable_eee_mode(priv);
+	} else {
+		/* We are asking for enabling the EEE but it is safe
+		 * to verify all by invoking the eee_init function.
+		 * In case of failure it will return an error.
+		 */
+		priv->eee_enabled = sxgbe_eee_init(priv);
+		if (!priv->eee_enabled)
+			return -EOPNOTSUPP;
+
+		/* Do not change tx_lpi_timer in case of failure */
+		priv->tx_lpi_timer = edata->tx_lpi_timer;
+	}
+
+	return phy_ethtool_set_eee(priv->phydev, edata);
+}
+
 static const struct ethtool_ops sxgbe_ethtool_ops = {
+	.get_eee = sxgbe_get_eee,
+	.set_eee = sxgbe_set_eee,
 };
 
 void sxgbe_set_ethtool_ops(struct net_device *netdev)