net: stmmac: mmc_core: Add GMAC LPI statistics

XGMAC MMC has already added LPI statistics. GMAC MMC lack of these
statistics. Add register definition and reading the LPI statistics
from registers.

Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: mindachen1987

drivers/net/ethernet/stmicro/stmmac/mmc_core.c

@@ -79,6 +79,12 @@
 #define MMC_RX_FIFO_OVERFLOW		0xd4
 #define MMC_RX_VLAN_FRAMES_GB		0xd8
 #define MMC_RX_WATCHDOG_ERROR		0xdc
+
+#define MMC_TX_LPI_USEC			0xec
+#define MMC_TX_LPI_TRAN			0xf0
+#define MMC_RX_LPI_USEC			0xf4
+#define MMC_RX_LPI_TRAN			0xf8
+
 /* IPC*/
 #define MMC_RX_IPC_INTR_MASK		0x100
 #define MMC_RX_IPC_INTR			0x108
@@ -283,6 +289,8 @@ static void dwmac_mmc_read(void __iomem *mmcaddr, struct stmmac_counters *mmc)
 	mmc->mmc_tx_excessdef += readl(mmcaddr + MMC_TX_EXCESSDEF);
 	mmc->mmc_tx_pause_frame += readl(mmcaddr + MMC_TX_PAUSE_FRAME);
 	mmc->mmc_tx_vlan_frame_g += readl(mmcaddr + MMC_TX_VLAN_FRAME_G);
+	mmc->mmc_tx_lpi_usec += readl(mmcaddr + MMC_TX_LPI_USEC);
+	mmc->mmc_tx_lpi_tran += readl(mmcaddr + MMC_TX_LPI_TRAN);
 
 	/* MMC RX counter registers */
 	mmc->mmc_rx_framecount_gb += readl(mmcaddr + MMC_RX_FRAMECOUNT_GB);
@@ -316,6 +324,9 @@ static void dwmac_mmc_read(void __iomem *mmcaddr, struct stmmac_counters *mmc)
 	mmc->mmc_rx_fifo_overflow += readl(mmcaddr + MMC_RX_FIFO_OVERFLOW);
 	mmc->mmc_rx_vlan_frames_gb += readl(mmcaddr + MMC_RX_VLAN_FRAMES_GB);
 	mmc->mmc_rx_watchdog_error += readl(mmcaddr + MMC_RX_WATCHDOG_ERROR);
+	mmc->mmc_rx_lpi_usec += readl(mmcaddr + MMC_RX_LPI_USEC);
+	mmc->mmc_rx_lpi_tran += readl(mmcaddr + MMC_RX_LPI_TRAN);
+
 	/* IPv4 */
 	mmc->mmc_rx_ipv4_gd += readl(mmcaddr + MMC_RX_IPV4_GD);
 	mmc->mmc_rx_ipv4_hderr += readl(mmcaddr + MMC_RX_IPV4_HDERR);