stmmac: add the Energy Efficient Ethernet support

This patch adds the Energy Efficient Ethernet support to the stmmac.

Please see the driver's documentation for further details about this support
in the driver.

Thanks also goes to Rayagond Kokatanur for his first implementation.

Note:
 to clearly manage and expose the lpi interrupt status and eee ethtool
 stats I've had to do some modifications to the driver's design and I
 found really useful to move other parts of the code (e.g. mmc irq stat)
 in the main directly. So this means that some core has been reworked
 to introduce the EEE.

v1: initial patch
v2: fixed some sparse issues (typos)
v3: erroneously sent the v2 renamed as v3
v4:
	o Fixed the return value of the stmmac_eee_init as suggested by D.Miller
	o Totally reviewed the ethtool support for EEE
	o Added a new internal parameter to tune the SW timer for TX LPI.
v5: do not change any eee setting in case of the stmmac_ethtool_op_set_eee fails
    (it has to return -EOPNOTSUPP in that case).

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 93 insertions, 8 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
index b5e4d02f15c9..bfe022605498 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
@@ -194,26 +194,107 @@ static void dwmac1000_pmt(void __iomem *ioaddr, unsigned long mode)
 }
 
 
-static void dwmac1000_irq_status(void __iomem *ioaddr)
+static int dwmac1000_irq_status(void __iomem *ioaddr)
 {
 	u32 intr_status = readl(ioaddr + GMAC_INT_STATUS);
+	int status = 0;
 
 	/* Not used events (e.g. MMC interrupts) are not handled. */
-	if ((intr_status & mmc_tx_irq))
-		CHIP_DBG(KERN_DEBUG "GMAC: MMC tx interrupt: 0x%08x\n",
+	if ((intr_status & mmc_tx_irq)) {
+		CHIP_DBG(KERN_INFO "GMAC: MMC tx interrupt: 0x%08x\n",
 		    readl(ioaddr + GMAC_MMC_TX_INTR));
-	if (unlikely(intr_status & mmc_rx_irq))
-		CHIP_DBG(KERN_DEBUG "GMAC: MMC rx interrupt: 0x%08x\n",
+		status |= core_mmc_tx_irq;
+	}
+	if (unlikely(intr_status & mmc_rx_irq)) {
+		CHIP_DBG(KERN_INFO "GMAC: MMC rx interrupt: 0x%08x\n",
 		    readl(ioaddr + GMAC_MMC_RX_INTR));
-	if (unlikely(intr_status & mmc_rx_csum_offload_irq))
-		CHIP_DBG(KERN_DEBUG "GMAC: MMC rx csum offload: 0x%08x\n",
+		status |= core_mmc_rx_irq;
+	}
+	if (unlikely(intr_status & mmc_rx_csum_offload_irq)) {
+		CHIP_DBG(KERN_INFO "GMAC: MMC rx csum offload: 0x%08x\n",
 		    readl(ioaddr + GMAC_MMC_RX_CSUM_OFFLOAD));
+		status |= core_mmc_rx_csum_offload_irq;
+	}
 	if (unlikely(intr_status & pmt_irq)) {
-		CHIP_DBG(KERN_DEBUG "GMAC: received Magic frame\n");
+		CHIP_DBG(KERN_INFO "GMAC: received Magic frame\n");
 		/* clear the PMT bits 5 and 6 by reading the PMT
 		 * status register. */
 		readl(ioaddr + GMAC_PMT);
+		status |= core_irq_receive_pmt_irq;
 	}
+	/* MAC trx/rx EEE LPI entry/exit interrupts */
+	if (intr_status & lpiis_irq) {
+		/* Clean LPI interrupt by reading the Reg 12 */
+		u32 lpi_status = readl(ioaddr + LPI_CTRL_STATUS);
+
+		if (lpi_status & LPI_CTRL_STATUS_TLPIEN) {
+			CHIP_DBG(KERN_INFO "GMAC TX entered in LPI\n");
+			status |= core_irq_tx_path_in_lpi_mode;
+		}
+		if (lpi_status & LPI_CTRL_STATUS_TLPIEX) {
+			CHIP_DBG(KERN_INFO "GMAC TX exit from LPI\n");
+			status |= core_irq_tx_path_exit_lpi_mode;
+		}
+		if (lpi_status & LPI_CTRL_STATUS_RLPIEN) {
+			CHIP_DBG(KERN_INFO "GMAC RX entered in LPI\n");
+			status |= core_irq_rx_path_in_lpi_mode;
+		}
+		if (lpi_status & LPI_CTRL_STATUS_RLPIEX) {
+			CHIP_DBG(KERN_INFO "GMAC RX exit from LPI\n");
+			status |= core_irq_rx_path_exit_lpi_mode;
+		}
+	}
+
+	return status;
+}
+
+static void  dwmac1000_set_eee_mode(void __iomem *ioaddr)
+{
+	u32 value;
+
+	/* Enable the link status receive on RGMII, SGMII ore SMII
+	 * receive path and instruct the transmit to enter in LPI
+	 * state. */
+	value = readl(ioaddr + LPI_CTRL_STATUS);
+	value |= LPI_CTRL_STATUS_LPIEN | LPI_CTRL_STATUS_LPITXA;
+	writel(value, ioaddr + LPI_CTRL_STATUS);
+}
+
+static void  dwmac1000_reset_eee_mode(void __iomem *ioaddr)
+{
+	u32 value;
+
+	value = readl(ioaddr + LPI_CTRL_STATUS);
+	value &= ~(LPI_CTRL_STATUS_LPIEN | LPI_CTRL_STATUS_LPITXA);
+	writel(value, ioaddr + LPI_CTRL_STATUS);
+}
+
+static void  dwmac1000_set_eee_pls(void __iomem *ioaddr, int link)
+{
+	u32 value;
+
+	value = readl(ioaddr + LPI_CTRL_STATUS);
+
+	if (link)
+		value |= LPI_CTRL_STATUS_PLS;
+	else
+		value &= ~LPI_CTRL_STATUS_PLS;
+
+	writel(value, ioaddr + LPI_CTRL_STATUS);
+}
+
+static void  dwmac1000_set_eee_timer(void __iomem *ioaddr, int ls, 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 + LPI_TIMER_CTRL);
 }
 
 static const struct stmmac_ops dwmac1000_ops = {
@@ -226,6 +307,10 @@ static const struct stmmac_ops dwmac1000_ops = {
 	.pmt = dwmac1000_pmt,
 	.set_umac_addr = dwmac1000_set_umac_addr,
 	.get_umac_addr = dwmac1000_get_umac_addr,
+	.set_eee_mode =  dwmac1000_set_eee_mode,
+	.reset_eee_mode =  dwmac1000_reset_eee_mode,
+	.set_eee_timer =  dwmac1000_set_eee_timer,
+	.set_eee_pls =  dwmac1000_set_eee_pls,
 };
 
 struct mac_device_info *dwmac1000_setup(void __iomem *ioaddr)