[PATCH v4] lpc32xx: Added ethernet driver

[PATCH v4] lpc32xx: Added ethernet driver

[Roland Stigge]

This patch adds an ethernet driver for the LPC32xx ARM SoC.

Signed-off-by: Roland Stigge <stigge@antcom.de>

---

Applies to v3.3-rc6

Changes since v3:
 * Jiffies wraparound fix via msecs_to_jiffies() and time_after()
 * Introduces symbolic names for status and control bits of descriptors
 * Tx_errors counting only once at one event
 * Use of_get_mac_address() and dev_hw_addr_random() to get/generate mac
   address
 * Merged lpc_eth.h into lpc_eth.c since it didn't share defs with other
   C files
 * Added interrupt handling via NAPI
 * Removed net_region_start and net_region_size from struct netdata_local
 * Removed (actually unused) platform_data
 * Put LPC32XX_IRAM_* into another resource
 * Use PAGE_ALIGN() for DMA size alignment
 * Define suspend/resume conditionally
 * Use module_platform_driver()
 * Use correct pointer types (pointers, dma_addr_t, phys_addr_t) instead
   of casts

 Thanks to Arnd Bergmann, Ben Hutchings, David Miller, Kevin Wells,
 Russell King and Joe Perches for reviewing!

 drivers/net/ethernet/Kconfig       |    1 
 drivers/net/ethernet/Makefile      |    1 
 drivers/net/ethernet/nxp/Kconfig   |    8 
 drivers/net/ethernet/nxp/Makefile  |    1 
 drivers/net/ethernet/nxp/lpc_eth.c | 1642 +++++++++++++++++++++++++++++++++++++
 5 files changed, 1653 insertions(+)

--- linux-2.6.orig/drivers/net/ethernet/Kconfig
+++ linux-2.6/drivers/net/ethernet/Kconfig
@@ -126,6 +126,7 @@ config NET_NETX
 
 source "drivers/net/ethernet/nuvoton/Kconfig"
 source "drivers/net/ethernet/nvidia/Kconfig"
+source "drivers/net/ethernet/nxp/Kconfig"
 source "drivers/net/ethernet/octeon/Kconfig"
 source "drivers/net/ethernet/oki-semi/Kconfig"
 
--- linux-2.6.orig/drivers/net/ethernet/Makefile
+++ linux-2.6/drivers/net/ethernet/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_NET_VENDOR_NATSEMI) += nats
 obj-$(CONFIG_NET_NETX) += netx-eth.o
 obj-$(CONFIG_NET_VENDOR_NUVOTON) += nuvoton/
 obj-$(CONFIG_NET_VENDOR_NVIDIA) += nvidia/
+obj-$(CONFIG_LPC_ENET) += nxp/
 obj-$(CONFIG_OCTEON_MGMT_ETHERNET) += octeon/
 obj-$(CONFIG_NET_VENDOR_OKI) += oki-semi/
 obj-$(CONFIG_ETHOC) += ethoc.o
--- /dev/null
+++ linux-2.6/drivers/net/ethernet/nxp/Kconfig
@@ -0,0 +1,8 @@
+config LPC_ENET
+        tristate "NXP ethernet MAC on LPC devices"
+        depends on ARCH_LPC32XX
+        select PHYLIB
+        help
+	  Say Y or M here if you want to use the NXP ethernet MAC included on
+	  some NXP LPC devices. You can safely enable this option for LPC32xx
+	  SoC. Also available as a module.
--- /dev/null
+++ linux-2.6/drivers/net/ethernet/nxp/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_LPC_ENET) += lpc_eth.o
--- /dev/null
+++ linux-2.6/drivers/net/ethernet/nxp/lpc_eth.c
@@ -0,0 +1,1642 @@
+/*
+ * drivers/net/ethernet/nxp/lpc_eth.c
+ *
+ * Author: Kevin Wells <kevin.wells@nxp.com>
+ *
+ * Copyright (C) 2010 NXP Semiconductors
+ * Copyright (C) 2012 Roland Stigge <stigge@antcom.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/crc32.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/ethtool.h>
+#include <linux/mii.h>
+#include <linux/clk.h>
+#include <linux/workqueue.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/phy.h>
+#include <linux/dma-mapping.h>
+#include <linux/of_net.h>
+#include <linux/types.h>
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <mach/board.h>
+#include <mach/platform.h>
+#include <mach/hardware.h>
+
+#define MODNAME "lpc-eth"
+#define DRV_VERSION "1.00"
+#define PHYDEF_ADDR 0x00
+
+#define ENET_MAXF_SIZE 1536
+#define ENET_RX_DESC 48
+#define ENET_TX_DESC 16
+
+#define NAPI_WEIGHT 16
+
+/*
+ * Ethernet MAC controller Register offsets
+ */
+#define LPC_ENET_MAC1(x)			(x + 0x000)
+#define LPC_ENET_MAC2(x)			(x + 0x004)
+#define LPC_ENET_IPGT(x)			(x + 0x008)
+#define LPC_ENET_IPGR(x)			(x + 0x00C)
+#define LPC_ENET_CLRT(x)			(x + 0x010)
+#define LPC_ENET_MAXF(x)			(x + 0x014)
+#define LPC_ENET_SUPP(x)			(x + 0x018)
+#define LPC_ENET_TEST(x)			(x + 0x01C)
+#define LPC_ENET_MCFG(x)			(x + 0x020)
+#define LPC_ENET_MCMD(x)			(x + 0x024)
+#define LPC_ENET_MADR(x)			(x + 0x028)
+#define LPC_ENET_MWTD(x)			(x + 0x02C)
+#define LPC_ENET_MRDD(x)			(x + 0x030)
+#define LPC_ENET_MIND(x)			(x + 0x034)
+#define LPC_ENET_SA0(x)				(x + 0x040)
+#define LPC_ENET_SA1(x)				(x + 0x044)
+#define LPC_ENET_SA2(x)				(x + 0x048)
+#define LPC_ENET_COMMAND(x)			(x + 0x100)
+#define LPC_ENET_STATUS(x)			(x + 0x104)
+#define LPC_ENET_RXDESCRIPTOR(x)		(x + 0x108)
+#define LPC_ENET_RXSTATUS(x)			(x + 0x10C)
+#define LPC_ENET_RXDESCRIPTORNUMBER(x)		(x + 0x110)
+#define LPC_ENET_RXPRODUCEINDEX(x)		(x + 0x114)
+#define LPC_ENET_RXCONSUMEINDEX(x)		(x + 0x118)
+#define LPC_ENET_TXDESCRIPTOR(x)		(x + 0x11C)
+#define LPC_ENET_TXSTATUS(x)			(x + 0x120)
+#define LPC_ENET_TXDESCRIPTORNUMBER(x)		(x + 0x124)
+#define LPC_ENET_TXPRODUCEINDEX(x)		(x + 0x128)
+#define LPC_ENET_TXCONSUMEINDEX(x)		(x + 0x12C)
+#define LPC_ENET_TSV0(x)			(x + 0x158)
+#define LPC_ENET_TSV1(x)			(x + 0x15C)
+#define LPC_ENET_RSV(x)				(x + 0x160)
+#define LPC_ENET_FLOWCONTROLCOUNTER(x)		(x + 0x170)
+#define LPC_ENET_FLOWCONTROLSTATUS(x)		(x + 0x174)
+#define LPC_ENET_RXFILTER_CTRL(x)		(x + 0x200)
+#define LPC_ENET_RXFILTERWOLSTATUS(x)		(x + 0x204)
+#define LPC_ENET_RXFILTERWOLCLEAR(x)		(x + 0x208)
+#define LPC_ENET_HASHFILTERL(x)			(x + 0x210)
+#define LPC_ENET_HASHFILTERH(x)			(x + 0x214)
+#define LPC_ENET_INTSTATUS(x)			(x + 0xFE0)
+#define LPC_ENET_INTENABLE(x)			(x + 0xFE4)
+#define LPC_ENET_INTCLEAR(x)			(x + 0xFE8)
+#define LPC_ENET_INTSET(x)			(x + 0xFEC)
+#define LPC_ENET_POWERDOWN(x)			(x + 0xFF4)
+
+/*
+ * mac1 register definitions
+ */
+#define LPC_MAC1_RECV_ENABLE			(1 << 0)
+#define LPC_MAC1_PASS_ALL_RX_FRAMES		(1 << 1)
+#define LPC_MAC1_RX_FLOW_CONTROL		(1 << 2)
+#define LPC_MAC1_TX_FLOW_CONTROL		(1 << 3)
+#define LPC_MAC1_LOOPBACK			(1 << 4)
+#define LPC_MAC1_RESET_TX			(1 << 8)
+#define LPC_MAC1_RESET_MCS_TX			(1 << 9)
+#define LPC_MAC1_RESET_RX			(1 << 10)
+#define LPC_MAC1_RESET_MCS_RX			(1 << 11)
+#define LPC_MAC1_SIMULATION_RESET		(1 << 14)
+#define LPC_MAC1_SOFT_RESET			(1 << 15)
+
+/*
+ * mac2 register definitions
+ */
+#define LPC_MAC2_FULL_DUPLEX			(1 << 0)
+#define LPC_MAC2_FRAME_LENGTH_CHECKING		(1 << 1)
+#define LPC_MAC2_HUGH_LENGTH_CHECKING		(1 << 2)
+#define LPC_MAC2_DELAYED_CRC			(1 << 3)
+#define LPC_MAC2_CRC_ENABLE			(1 << 4)
+#define LPC_MAC2_PAD_CRC_ENABLE			(1 << 5)
+#define LPC_MAC2_VLAN_PAD_ENABLE		(1 << 6)
+#define LPC_MAC2_AUTO_DETECT_PAD_ENABLE		(1 << 7)
+#define LPC_MAC2_PURE_PREAMBLE_ENFORCEMENT	(1 << 8)
+#define LPC_MAC2_LONG_PREAMBLE_ENFORCEMENT	(1 << 9)
+#define LPC_MAC2_NO_BACKOFF			(1 << 12)
+#define LPC_MAC2_BACK_PRESSURE			(1 << 13)
+#define LPC_MAC2_EXCESS_DEFER			(1 << 14)
+
+/*
+ * ipgt register definitions
+ */
+#define LPC_IPGT_LOAD(n)			((n) & 0x7F)
+
+/*
+ * ipgr register definitions
+ */
+#define LPC_IPGR_LOAD_PART2(n)			((n) & 0x7F)
+#define LPC_IPGR_LOAD_PART1(n)			(((n) & 0x7F) << 8)
+
+/*
+ * clrt register definitions
+ */
+#define LPC_CLRT_LOAD_RETRY_MAX(n)		((n) & 0xF)
+#define LPC_CLRT_LOAD_COLLISION_WINDOW(n)	(((n) & 0x3F) << 8)
+
+/*
+ * maxf register definitions
+ */
+#define LPC_MAXF_LOAD_MAX_FRAME_LEN(n)		((n) & 0xFFFF)
+
+/*
+ * supp register definitions
+ */
+#define LPC_SUPP_SPEED				(1 << 8)
+#define LPC_SUPP_RESET_RMII			(1 << 11)
+
+/*
+ * test register definitions
+ */
+#define LPC_TEST_SHORTCUT_PAUSE_QUANTA		(1 << 0)
+#define LPC_TEST_PAUSE				(1 << 1)
+#define LPC_TEST_BACKPRESSURE			(1 << 2)
+
+/*
+ * mcfg register definitions
+ */
+#define LPC_MCFG_SCAN_INCREMENT			(1 << 0)
+#define LPC_MCFG_SUPPRESS_PREAMBLE		(1 << 1)
+#define LPC_MCFG_CLOCK_SELECT(n)		(((n) & 0x7) << 2)
+#define LPC_MCFG_CLOCK_HOST_DIV_4		0
+#define LPC_MCFG_CLOCK_HOST_DIV_6		2
+#define LPC_MCFG_CLOCK_HOST_DIV_8		3
+#define LPC_MCFG_CLOCK_HOST_DIV_10		4
+#define LPC_MCFG_CLOCK_HOST_DIV_14		5
+#define LPC_MCFG_CLOCK_HOST_DIV_20		6
+#define LPC_MCFG_CLOCK_HOST_DIV_28		7
+#define LPC_MCFG_RESET_MII_MGMT			(1 << 15)
+
+/*
+ * mcmd register definitions
+ */
+#define LPC_MCMD_READ				(1 << 0)
+#define LPC_MCMD_SCAN				(1 << 1)
+
+/*
+ * madr register definitions
+ */
+#define LPC_MADR_REGISTER_ADDRESS(n)		((n) & 0x1F)
+#define LPC_MADR_PHY_0ADDRESS(n)		(((n) & 0x1F) << 8)
+
+/*
+ * mwtd register definitions
+ */
+#define LPC_MWDT_WRITE(n)			((n) & 0xFFFF)
+
+/*
+ * mrdd register definitions
+ */
+#define LPC_MRDD_READ_MASK			0xFFFF
+
+/*
+ * mind register definitions
+ */
+#define LPC_MIND_BUSY				(1 << 0)
+#define LPC_MIND_SCANNING			(1 << 1)
+#define LPC_MIND_NOT_VALID			(1 << 2)
+#define LPC_MIND_MII_LINK_FAIL			(1 << 3)
+
+/*
+ * command register definitions
+ */
+#define LPC_COMMAND_RXENABLE			(1 << 0)
+#define LPC_COMMAND_TXENABLE			(1 << 1)
+#define LPC_COMMAND_REG_RESET			(1 << 3)
+#define LPC_COMMAND_TXRESET			(1 << 4)
+#define LPC_COMMAND_RXRESET			(1 << 5)
+#define LPC_COMMAND_PASSRUNTFRAME		(1 << 6)
+#define LPC_COMMAND_PASSRXFILTER		(1 << 7)
+#define LPC_COMMAND_TXFLOWCONTROL		(1 << 8)
+#define LPC_COMMAND_RMII			(1 << 9)
+#define LPC_COMMAND_FULLDUPLEX			(1 << 10)
+
+/*
+ * status register definitions
+ */
+#define LPC_STATUS_RXACTIVE			(1 << 0)
+#define LPC_STATUS_TXACTIVE			(1 << 1)
+
+/*
+ * tsv0 register definitions
+ */
+#define LPC_TSV0_CRC_ERROR			(1 << 0)
+#define LPC_TSV0_LENGTH_CHECK_ERROR		(1 << 1)
+#define LPC_TSV0_LENGTH_OUT_OF_RANGE		(1 << 2)
+#define LPC_TSV0_DONE				(1 << 3)
+#define LPC_TSV0_MULTICAST			(1 << 4)
+#define LPC_TSV0_BROADCAST			(1 << 5)
+#define LPC_TSV0_PACKET_DEFER			(1 << 6)
+#define LPC_TSV0_ESCESSIVE_DEFER		(1 << 7)
+#define LPC_TSV0_ESCESSIVE_COLLISION		(1 << 8)
+#define LPC_TSV0_LATE_COLLISION			(1 << 9)
+#define LPC_TSV0_GIANT				(1 << 10)
+#define LPC_TSV0_UNDERRUN			(1 << 11)
+#define LPC_TSV0_TOTAL_BYTES(n)			(((n) >> 12) & 0xFFFF)
+#define LPC_TSV0_CONTROL_FRAME			(1 << 28)
+#define LPC_TSV0_PAUSE				(1 << 29)
+#define LPC_TSV0_BACKPRESSURE			(1 << 30)
+#define LPC_TSV0_VLAN				(1 << 31)
+
+/*
+ * tsv1 register definitions
+ */
+#define LPC_TSV1_TRANSMIT_BYTE_COUNT(n)		((n) & 0xFFFF)
+#define LPC_TSV1_COLLISION_COUNT(n)		(((n) >> 16) & 0xF)
+
+/*
+ * rsv register definitions
+ */
+#define LPC_RSV_RECEIVED_BYTE_COUNT(n)		((n) & 0xFFFF)
+#define LPC_RSV_RXDV_EVENT_IGNORED		(1 << 16)
+#define LPC_RSV_RXDV_EVENT_PREVIOUSLY_SEEN	(1 << 17)
+#define LPC_RSV_CARRIER_EVNT_PREVIOUS_SEEN	(1 << 18)
+#define LPC_RSV_RECEIVE_CODE_VIOLATION		(1 << 19)
+#define LPC_RSV_CRC_ERROR			(1 << 20)
+#define LPC_RSV_LENGTH_CHECK_ERROR		(1 << 21)
+#define LPC_RSV_LENGTH_OUT_OF_RANGE		(1 << 22)
+#define LPC_RSV_RECEIVE_OK			(1 << 23)
+#define LPC_RSV_MULTICAST			(1 << 24)
+#define LPC_RSV_BROADCAST			(1 << 25)
+#define LPC_RSV_DRIBBLE_NIBBLE			(1 << 26)
+#define LPC_RSV_CONTROL_FRAME			(1 << 27)
+#define LPC_RSV_PAUSE				(1 << 28)
+#define LPC_RSV_UNSUPPORTED_OPCODE		(1 << 29)
+#define LPC_RSV_VLAN				(1 << 30)
+
+/*
+ * flowcontrolcounter register definitions
+ */
+#define LPC_FCCR_MIRRORCOUNTER(n)		((n) & 0xFFFF)
+#define LPC_FCCR_PAUSETIMER(n)			(((n) >> 16) & 0xFFFF)
+
+/*
+ * flowcontrolstatus register definitions
+ */
+#define LPC_FCCR_MIRRORCOUNTERCURRENT(n)	((n) & 0xFFFF)
+
+/*
+ * rxfliterctrl, rxfilterwolstatus, and rxfilterwolclear shared
+ * register definitions
+ */
+#define LPC_RXFLTRW_ACCEPTUNICAST		(1 << 0)
+#define LPC_RXFLTRW_ACCEPTUBROADCAST		(1 << 1)
+#define LPC_RXFLTRW_ACCEPTUMULTICAST		(1 << 2)
+#define LPC_RXFLTRW_ACCEPTUNICASTHASH		(1 << 3)
+#define LPC_RXFLTRW_ACCEPTUMULTICASTHASH	(1 << 4)
+#define LPC_RXFLTRW_ACCEPTPERFECT		(1 << 5)
+
+/*
+ * rxfliterctrl register definitions
+ */
+#define LPC_RXFLTRWSTS_MAGICPACKETENWOL		(1 << 12)
+#define LPC_RXFLTRWSTS_RXFILTERENWOL		(1 << 13)
+
+/*
+ * rxfilterwolstatus/rxfilterwolclear register definitions
+ */
+#define LPC_RXFLTRWSTS_RXFILTERWOL		(1 << 7)
+#define LPC_RXFLTRWSTS_MAGICPACKETWOL		(1 << 8)
+
+/*
+ * intstatus, intenable, intclear, and Intset shared register
+ * definitions
+ */
+#define LPC_MACINT_RXOVERRUNINTEN		(1 << 0)
+#define LPC_MACINT_RXERRORONINT			(1 << 1)
+#define LPC_MACINT_RXFINISHEDINTEN		(1 << 2)
+#define LPC_MACINT_RXDONEINTEN			(1 << 3)
+#define LPC_MACINT_TXUNDERRUNINTEN		(1 << 4)
+#define LPC_MACINT_TXERRORINTEN			(1 << 5)
+#define LPC_MACINT_TXFINISHEDINTEN		(1 << 6)
+#define LPC_MACINT_TXDONEINTEN			(1 << 7)
+#define LPC_MACINT_SOFTINTEN			(1 << 12)
+#define LPC_MACINT_WAKEUPINTEN			(1 << 13)
+
+/*
+ * powerdown register definitions
+ */
+#define LPC_POWERDOWN_MACAHB			(1 << 31)
+
+static inline phy_interface_t lpc_phy_interface_mode(void)
+{
+#ifdef CONFIG_ARCH_LPC32XX_MII_SUPPORT
+	return PHY_INTERFACE_MODE_MII;
+#else
+	return PHY_INTERFACE_MODE_RMII;
+#endif
+}
+
+static inline int use_iram_for_net(void)
+{
+#ifdef CONFIG_ARCH_LPC32XX_IRAM_FOR_NET
+	return 1;
+#else
+	return 0;
+#endif
+}
+
+/* Receive Status information word */
+#define RXSTATUS_SIZE			0x000007FF
+#define RXSTATUS_CONTROL		(1 << 18)
+#define RXSTATUS_VLAN			(1 << 19)
+#define RXSTATUS_FILTER			(1 << 20)
+#define RXSTATUS_MULTICAST		(1 << 21)
+#define RXSTATUS_BROADCAST		(1 << 22)
+#define RXSTATUS_CRC			(1 << 23)
+#define RXSTATUS_SYMBOL			(1 << 24)
+#define RXSTATUS_LENGTH			(1 << 25)
+#define RXSTATUS_RANGE			(1 << 26)
+#define RXSTATUS_ALIGN			(1 << 27)
+#define RXSTATUS_OVERRUN		(1 << 28)
+#define RXSTATUS_NODESC			(1 << 29)
+#define RXSTATUS_LAST			(1 << 30)
+#define RXSTATUS_ERROR			(1 << 31)
+
+#define RXSTATUS_STATUS_ERROR \
+	(RXSTATUS_NODESC | RXSTATUS_OVERRUN | RXSTATUS_ALIGN | RXSTATUS_RANGE \
+	 | RXSTATUS_LENGTH | RXSTATUS_SYMBOL | RXSTATUS_CRC)
+
+/* Receive Descriptor control word */
+#define RXDESC_CONTROL_SIZE		0x000007FF
+#define RXDESC_CONTROL_INT		(1 << 31)
+
+/* Transmit Status information word */
+#define TXSTATUS_COLLISIONS_GET(x)	(((x) >> 21) & 0xF)
+#define TXSTATUS_DEFER			(1 << 25)
+#define TXSTATUS_EXCESSDEFER		(1 << 26)
+#define TXSTATUS_EXCESSCOLL		(1 << 27)
+#define TXSTATUS_LATECOLL		(1 << 28)
+#define TXSTATUS_UNDERRUN		(1 << 29)
+#define TXSTATUS_NODESC			(1 << 30)
+#define TXSTATUS_ERROR			(1 << 31)
+
+/* Transmit Descriptor control word */
+#define TXDESC_CONTROL_SIZE		0x000007FF
+#define TXDESC_CONTROL_OVERRIDE		(1 << 26)
+#define TXDESC_CONTROL_HUGE		(1 << 27)
+#define TXDESC_CONTROL_PAD		(1 << 28)
+#define TXDESC_CONTROL_CRC		(1 << 29)
+#define TXDESC_CONTROL_LAST		(1 << 30)
+#define TXDESC_CONTROL_INT		(1 << 31)
+
+static int lpc_eth_hard_start_xmit(struct sk_buff *skb,
+	struct net_device *ndev);
+
+/*
+ * Transmit timeout, default 2.5 seconds.
+ */
+static int watchdog = 2500;
+module_param(watchdog, int, 0400);
+MODULE_PARM_DESC(watchdog, "transmit timeout in milliseconds");
+
+/*
+ * Structure of a TX/RX descriptors and RX status
+ */
+struct txrx_desc_t {
+	volatile u32 packet;
+	volatile u32 control;
+};
+struct rx_status_t {
+	volatile u32 statusinfo;
+	volatile u32 statushashcrc;
+};
+
+/*
+ * Device driver data structure
+ */
+struct netdata_local {
+	struct platform_device	*pdev;
+	struct net_device	*ndev;
+	spinlock_t		lock;
+	void __iomem		*net_base;
+	u32			msg_enable;
+	struct sk_buff		*skb[ENET_TX_DESC];
+	unsigned int		last_tx_idx;
+	unsigned int		num_used_tx_buffs;
+	struct mii_bus		*mii_bus;
+	struct phy_device	*phy_dev;
+	struct clk		*clk;
+	dma_addr_t		dma_buff_base_p;
+	void			*dma_buff_base_v;
+	size_t			dma_buff_size;
+	struct txrx_desc_t	*tx_desc_v[ENET_TX_DESC];
+	u32			*tx_stat_v[ENET_TX_DESC];
+	void			*tx_buff_v[ENET_TX_DESC];
+	struct txrx_desc_t	*rx_desc_v[ENET_RX_DESC];
+	struct rx_status_t	*rx_stat_v[ENET_RX_DESC];
+	void			*rx_buff_v[ENET_RX_DESC];
+	int			link;
+	int			speed;
+	int			duplex;
+	struct napi_struct	napi;
+};
+
+/*
+ * MAC support functions
+ */
+static void __lpc_set_mac(struct netdata_local *pldat, u8 *mac)
+{
+	u32 tmp;
+
+	/* Set station address */
+	tmp = mac[0] | ((u32)mac[1] << 8);
+	writel(tmp, LPC_ENET_SA2(pldat->net_base));
+	tmp = mac[2] | ((u32)mac[3] << 8);
+	writel(tmp, LPC_ENET_SA1(pldat->net_base));
+	tmp = mac[4] | ((u32)mac[5] << 8);
+	writel(tmp, LPC_ENET_SA0(pldat->net_base));
+
+	netdev_dbg(pldat->ndev, "Ethernet MAC address %pM\n", mac);
+}
+
+static void __lpc_get_mac(struct netdata_local *pldat, u8 *mac)
+{
+	u32 tmp;
+
+	/* Get station address */
+	tmp = readl(LPC_ENET_SA2(pldat->net_base));
+	mac[0] = tmp & 0xFF;
+	mac[1] = tmp >> 8;
+	tmp = readl(LPC_ENET_SA1(pldat->net_base));
+	mac[2] = tmp & 0xFF;
+	mac[3] = tmp >> 8;
+	tmp = readl(LPC_ENET_SA0(pldat->net_base));
+	mac[4] = tmp & 0xFF;
+	mac[5] = tmp >> 8;
+}
+
+static void __lpc_eth_clock_enable(struct netdata_local *pldat,
+	int enable)
+{
+	if (enable)
+		clk_enable(pldat->clk);
+	else
+		clk_disable(pldat->clk);
+}
+
+static void __lpc_params_setup(struct netdata_local *pldat)
+{
+	u32 tmp;
+
+	if (pldat->duplex == DUPLEX_FULL) {
+		tmp = readl(LPC_ENET_MAC2(pldat->net_base));
+		tmp |= LPC_MAC2_FULL_DUPLEX;
+		writel(tmp, LPC_ENET_MAC2(pldat->net_base));
+		tmp = readl(LPC_ENET_COMMAND(pldat->net_base));
+		tmp |= LPC_COMMAND_FULLDUPLEX;
+		writel(tmp, LPC_ENET_COMMAND(pldat->net_base));
+		writel(LPC_IPGT_LOAD(0x15), LPC_ENET_IPGT(pldat->net_base));
+	} else {
+		tmp = readl(LPC_ENET_MAC2(pldat->net_base));
+		tmp &= ~LPC_MAC2_FULL_DUPLEX;
+		writel(tmp, LPC_ENET_MAC2(pldat->net_base));
+		tmp = readl(LPC_ENET_COMMAND(pldat->net_base));
+		tmp &= ~LPC_COMMAND_FULLDUPLEX;
+		writel(tmp, LPC_ENET_COMMAND(pldat->net_base));
+		writel(LPC_IPGT_LOAD(0x12), LPC_ENET_IPGT(pldat->net_base));
+	}
+
+	if (pldat->speed == SPEED_100)
+		writel(LPC_SUPP_SPEED, LPC_ENET_SUPP(pldat->net_base));
+	else
+		writel(0, LPC_ENET_SUPP(pldat->net_base));
+}
+
+static void __lpc_eth_reset(struct netdata_local *pldat)
+{
+	/* Reset all MAC logic */
+	writel((LPC_MAC1_RESET_TX | LPC_MAC1_RESET_MCS_TX | LPC_MAC1_RESET_RX |
+		LPC_MAC1_RESET_MCS_RX | LPC_MAC1_SIMULATION_RESET |
+		LPC_MAC1_SOFT_RESET), LPC_ENET_MAC1(pldat->net_base));
+	writel((LPC_COMMAND_REG_RESET | LPC_COMMAND_TXRESET |
+		LPC_COMMAND_RXRESET), LPC_ENET_COMMAND(pldat->net_base));
+}
+
+static int __lpc_mii_mngt_reset(struct netdata_local *pldat)
+{
+	/* Reset MII management hardware */
+	writel(LPC_MCFG_RESET_MII_MGMT, LPC_ENET_MCFG(pldat->net_base));
+
+	/* Setup MII clock to slowest rate with a /28 divider */
+	writel(LPC_MCFG_CLOCK_SELECT(LPC_MCFG_CLOCK_HOST_DIV_28),
+		LPC_ENET_MCFG(pldat->net_base));
+
+	return 0;
+}
+
+static inline phys_addr_t __va_to_pa(void *addr, struct netdata_local *pldat)
+{
+	phys_addr_t phaddr;
+
+	phaddr = addr - pldat->dma_buff_base_v;
+	phaddr += pldat->dma_buff_base_p;
+
+	return phaddr;
+}
+
+static void lpc_eth_enable_int(void __iomem *regbase)
+{
+	writel((LPC_MACINT_RXDONEINTEN | LPC_MACINT_TXDONEINTEN),
+		LPC_ENET_INTENABLE(regbase));
+}
+
+static void lpc_eth_disable_int(void __iomem *regbase)
+{
+	writel(0, LPC_ENET_INTENABLE(regbase));
+}
+
+/* Setup TX/RX descriptors */
+static void __lpc_txrx_desc_setup(struct netdata_local *pldat)
+{
+	u32 *ptxstat;
+	void *tbuff;
+	int i;
+	struct txrx_desc_t *ptxrxdesc;
+	struct rx_status_t *prxstat;
+
+	tbuff = PTR_ALIGN(pldat->dma_buff_base_v, 4);
+
+	/* Setup TX descriptors, status, and buffers */
+	for (i = 0; i < ENET_TX_DESC; i++) {
+		pldat->tx_desc_v[i] = tbuff;
+		tbuff += sizeof(struct txrx_desc_t);
+	}
+	for (i = 0; i < ENET_TX_DESC; i++) {
+		pldat->tx_stat_v[i] = tbuff;
+		tbuff += sizeof(u32);
+	}
+	tbuff = PTR_ALIGN(tbuff, 4);
+	for (i = 0; i < ENET_TX_DESC; i++) {
+		pldat->tx_buff_v[i] = tbuff;
+		tbuff += ENET_MAXF_SIZE;
+	}
+
+	/* Setup RX descriptors, status, and buffers */
+	for (i = 0; i < ENET_RX_DESC; i++) {
+		pldat->rx_desc_v[i] = tbuff;
+		tbuff += sizeof(struct txrx_desc_t);
+	}
+	tbuff = PTR_ALIGN(tbuff, 4);
+	for (i = 0; i < ENET_RX_DESC; i++) {
+		pldat->rx_stat_v[i] = tbuff;
+		tbuff += sizeof(struct rx_status_t);
+	}
+	tbuff = PTR_ALIGN(tbuff, 4);
+	for (i = 0; i < ENET_RX_DESC; i++) {
+		pldat->rx_buff_v[i] = tbuff;
+		tbuff += ENET_MAXF_SIZE;
+	}
+
+	/* Map the TX descriptors to the TX buffers in hardware */
+	for (i = 0; i < ENET_TX_DESC; i++) {
+		ptxstat = pldat->tx_stat_v[i];
+		ptxrxdesc = pldat->tx_desc_v[i];
+
+		ptxrxdesc->packet = __va_to_pa(pldat->tx_buff_v[i], pldat);
+		ptxrxdesc->control = 0;
+		*ptxstat = 0;
+	}
+
+	/* Map the RX descriptors to the RX buffers in hardware */
+	for (i = 0; i < ENET_RX_DESC; i++) {
+		prxstat = pldat->rx_stat_v[i];
+		ptxrxdesc = pldat->rx_desc_v[i];
+
+		ptxrxdesc->packet = __va_to_pa(pldat->rx_buff_v[i], pldat);
+		ptxrxdesc->control = RXDESC_CONTROL_INT | (ENET_MAXF_SIZE - 1);
+		prxstat->statusinfo = 0;
+		prxstat->statushashcrc = 0;
+	}
+
+	/* Setup base addresses in hardware to point to buffers and
+	   descriptors */
+	writel((ENET_TX_DESC - 1),
+		LPC_ENET_TXDESCRIPTORNUMBER(pldat->net_base));
+	writel(__va_to_pa(pldat->tx_desc_v[0], pldat),
+		LPC_ENET_TXDESCRIPTOR(pldat->net_base));
+	writel(__va_to_pa(pldat->tx_stat_v[0], pldat),
+		LPC_ENET_TXSTATUS(pldat->net_base));
+	writel((ENET_RX_DESC - 1),
+		LPC_ENET_RXDESCRIPTORNUMBER(pldat->net_base));
+	writel(__va_to_pa(pldat->rx_desc_v[0], pldat),
+		LPC_ENET_RXDESCRIPTOR(pldat->net_base));
+	writel(__va_to_pa(pldat->rx_stat_v[0], pldat),
+		LPC_ENET_RXSTATUS(pldat->net_base));
+}
+
+static void __lpc_eth_init(struct netdata_local *pldat)
+{
+	u32 tmp;
+
+	/* Disable controller and reset */
+	tmp = readl(LPC_ENET_COMMAND(pldat->net_base));
+	tmp &= ~LPC_COMMAND_RXENABLE | LPC_COMMAND_TXENABLE;
+	writel(tmp, LPC_ENET_COMMAND(pldat->net_base));
+	tmp = readl(LPC_ENET_MAC1(pldat->net_base));
+	tmp &= ~LPC_MAC1_RECV_ENABLE;
+	writel(tmp, LPC_ENET_MAC1(pldat->net_base));
+
+	/* Initial MAC setup */
+	writel(LPC_MAC1_PASS_ALL_RX_FRAMES, LPC_ENET_MAC1(pldat->net_base));
+	writel((LPC_MAC2_PAD_CRC_ENABLE | LPC_MAC2_CRC_ENABLE),
+		LPC_ENET_MAC2(pldat->net_base));
+	writel(ENET_MAXF_SIZE, LPC_ENET_MAXF(pldat->net_base));
+
+	/* Collision window, gap */
+	writel((LPC_CLRT_LOAD_RETRY_MAX(0xF) |
+		LPC_CLRT_LOAD_COLLISION_WINDOW(0x37)),
+		LPC_ENET_CLRT(pldat->net_base));
+	writel(LPC_IPGR_LOAD_PART2(0x12), LPC_ENET_IPGR(pldat->net_base));
+
+	if (lpc_phy_interface_mode() == PHY_INTERFACE_MODE_MII)
+		writel(LPC_COMMAND_PASSRUNTFRAME,
+			LPC_ENET_COMMAND(pldat->net_base));
+	else {
+		writel((LPC_COMMAND_PASSRUNTFRAME | LPC_COMMAND_RMII),
+			LPC_ENET_COMMAND(pldat->net_base));
+		writel(LPC_SUPP_RESET_RMII, LPC_ENET_SUPP(pldat->net_base));
+	}
+
+	__lpc_params_setup(pldat);
+
+	/* Setup TX and RX descriptors */
+	__lpc_txrx_desc_setup(pldat);
+
+	/* Setup packet filtering */
+	writel((LPC_RXFLTRW_ACCEPTUBROADCAST | LPC_RXFLTRW_ACCEPTPERFECT),
+		LPC_ENET_RXFILTER_CTRL(pldat->net_base));
+
+	/* Clear and enable interrupts */
+	writel(0xFFFF, LPC_ENET_INTCLEAR(pldat->net_base));
+	lpc_eth_enable_int(pldat->net_base);
+
+	/* Get the next TX buffer output index */
+	pldat->num_used_tx_buffs = 0;
+	pldat->last_tx_idx =
+		readl(LPC_ENET_TXCONSUMEINDEX(pldat->net_base));
+
+	/* Enable controller */
+	tmp = readl(LPC_ENET_COMMAND(pldat->net_base));
+	tmp |= LPC_COMMAND_RXENABLE | LPC_COMMAND_TXENABLE;
+	writel(tmp, LPC_ENET_COMMAND(pldat->net_base));
+	tmp = readl(LPC_ENET_MAC1(pldat->net_base));
+	tmp |= LPC_MAC1_RECV_ENABLE;
+	writel(tmp, LPC_ENET_MAC1(pldat->net_base));
+}
+
+static void __lpc_eth_shutdown(struct netdata_local *pldat)
+{
+	/* Reset ethernet and power down PHY */
+	__lpc_eth_reset(pldat);
+	writel(0, LPC_ENET_MAC1(pldat->net_base));
+	writel(0, LPC_ENET_MAC2(pldat->net_base));
+}
+
+/*
+ * MAC<--->PHY support functions
+ */
+static int lpc_mdio_read(struct mii_bus *bus, int phy_id, int phyreg)
+{
+	struct netdata_local *pldat = bus->priv;
+	unsigned long timeout = jiffies + msecs_to_jiffies(100);
+	int lps;
+
+	writel(((phy_id << 8) | phyreg), LPC_ENET_MADR(pldat->net_base));
+	writel(LPC_MCMD_READ, LPC_ENET_MCMD(pldat->net_base));
+
+	/* Wait for unbusy status */
+	while (readl(LPC_ENET_MIND(pldat->net_base)) & LPC_MIND_BUSY) {
+		if (time_after(jiffies, timeout))
+			return -EIO;
+		cpu_relax();
+	}
+
+	lps = readl(LPC_ENET_MRDD(pldat->net_base));
+	writel(0, LPC_ENET_MCMD(pldat->net_base));
+
+	return lps;
+}
+
+static int lpc_mdio_write(struct mii_bus *bus, int phy_id, int phyreg,
+			u16 phydata)
+{
+	struct netdata_local *pldat = bus->priv;
+	unsigned long timeout = jiffies + msecs_to_jiffies(100);
+
+	writel(((phy_id << 8) | phyreg), LPC_ENET_MADR(pldat->net_base));
+	writel(phydata, LPC_ENET_MWTD(pldat->net_base));
+
+	/* Wait for completion */
+	while (readl(LPC_ENET_MIND(pldat->net_base)) & LPC_MIND_BUSY) {
+		if (time_after(jiffies, timeout))
+			return -EIO;
+		cpu_relax();
+	}
+
+	return 0;
+}
+
+static int lpc_mdio_reset(struct mii_bus *bus)
+{
+	return __lpc_mii_mngt_reset((struct netdata_local *)bus->priv);
+}
+
+static void lpc_handle_link_change(struct net_device *ndev)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+	struct phy_device *phydev = pldat->phy_dev;
+	unsigned long flags;
+
+	int status_change = 0;
+
+	spin_lock_irqsave(&pldat->lock, flags);
+
+	if (phydev->link) {
+		if ((pldat->speed != phydev->speed) ||
+		    (pldat->duplex != phydev->duplex)) {
+			pldat->speed = phydev->speed;
+			pldat->duplex = phydev->duplex;
+			status_change = 1;
+		}
+	}
+
+	if (phydev->link != pldat->link) {
+		if (!phydev->link) {
+			pldat->speed = 0;
+			pldat->duplex = -1;
+		}
+		pldat->link = phydev->link;
+
+		status_change = 1;
+	}
+
+	spin_unlock_irqrestore(&pldat->lock, flags);
+
+	if (status_change)
+		__lpc_params_setup(pldat);
+}
+
+static int lpc_mii_probe(struct net_device *ndev)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+	struct phy_device *phydev = NULL;
+	int phy_addr;
+
+	/* find the first phy */
+	for (phy_addr = 0; phy_addr < PHY_MAX_ADDR; phy_addr++) {
+		if (pldat->mii_bus->phy_map[phy_addr]) {
+			phydev = pldat->mii_bus->phy_map[phy_addr];
+			break;
+		}
+	}
+
+	if (!phydev) {
+		netdev_err(ndev, "no PHY found\n");
+		return -ENODEV;
+	}
+
+	/* Attach to the PHY */
+	if (lpc_phy_interface_mode() == PHY_INTERFACE_MODE_MII)
+		netdev_info(ndev, "using MII interface\n");
+	else
+		netdev_info(ndev, "using RMII interface\n");
+	phydev = phy_connect(ndev, dev_name(&phydev->dev),
+		&lpc_handle_link_change, 0, lpc_phy_interface_mode());
+
+	if (IS_ERR(phydev)) {
+		netdev_err(ndev, "Could not attach to PHY\n");
+		return PTR_ERR(phydev);
+	}
+
+	/* mask with MAC supported features */
+	phydev->supported &= PHY_BASIC_FEATURES;
+
+	phydev->advertising = phydev->supported;
+
+	pldat->link = 0;
+	pldat->speed = 0;
+	pldat->duplex = -1;
+	pldat->phy_dev = phydev;
+
+	return 0;
+}
+
+static int lpc_mii_init(struct netdata_local *pldat)
+{
+	int err = -ENXIO, i;
+
+	pldat->mii_bus = mdiobus_alloc();
+	if (!pldat->mii_bus) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+
+	/* Setup MII mode */
+	if (lpc_phy_interface_mode() == PHY_INTERFACE_MODE_MII)
+		writel(LPC_COMMAND_PASSRUNTFRAME,
+			LPC_ENET_COMMAND(pldat->net_base));
+	else {
+		writel((LPC_COMMAND_PASSRUNTFRAME | LPC_COMMAND_RMII),
+			LPC_ENET_COMMAND(pldat->net_base));
+		writel(LPC_SUPP_RESET_RMII, LPC_ENET_SUPP(pldat->net_base));
+	}
+
+	pldat->mii_bus->name = "lpc_mii_bus";
+	pldat->mii_bus->read = &lpc_mdio_read;
+	pldat->mii_bus->write = &lpc_mdio_write;
+	pldat->mii_bus->reset = &lpc_mdio_reset;
+	snprintf(pldat->mii_bus->id, MII_BUS_ID_SIZE, "%x", pldat->pdev->id);
+	pldat->mii_bus->priv = pldat;
+	pldat->mii_bus->parent = &pldat->pdev->dev;
+	pldat->mii_bus->phy_mask = 0xFFFFFFF0;
+
+	pldat->mii_bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
+	if (!pldat->mii_bus->irq) {
+		err = -ENOMEM;
+		goto err_out_1;
+	}
+
+	for (i = 0; i < PHY_MAX_ADDR; i++)
+		pldat->mii_bus->irq[i] = PHY_POLL;
+
+	platform_set_drvdata(pldat->pdev, pldat->mii_bus);
+
+	if (mdiobus_register(pldat->mii_bus))
+		goto err_out_free_mdio_irq;
+
+	if (lpc_mii_probe(pldat->ndev) != 0)
+		goto err_out_unregister_bus;
+
+	return 0;
+
+err_out_unregister_bus:
+	mdiobus_unregister(pldat->mii_bus);
+err_out_free_mdio_irq:
+	kfree(pldat->mii_bus->irq);
+err_out_1:
+	mdiobus_free(pldat->mii_bus);
+err_out:
+	return err;
+}
+
+static void __lpc_handle_xmit(struct net_device *ndev)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+	struct sk_buff *skb;
+	u32 txcidx, *ptxstat, txstat;
+
+	txcidx = readl(LPC_ENET_TXCONSUMEINDEX(pldat->net_base));
+	while (pldat->last_tx_idx != txcidx) {
+		skb = pldat->skb[pldat->last_tx_idx];
+
+		/* A buffer is available, get buffer status */
+		ptxstat = pldat->tx_stat_v[pldat->last_tx_idx];
+		txstat = *ptxstat;
+
+		/* Next buffer and decrement used buffer counter */
+		pldat->num_used_tx_buffs--;
+		pldat->last_tx_idx++;
+		if (pldat->last_tx_idx >= ENET_TX_DESC)
+			pldat->last_tx_idx = 0;
+
+		/* Update collision counter */
+		ndev->stats.collisions += TXSTATUS_COLLISIONS_GET(txstat);
+
+		/* Any errors occurred? */
+		if (txstat & TXSTATUS_ERROR) {
+			if (txstat & TXSTATUS_UNDERRUN) {
+				/* FIFO underrun */
+				ndev->stats.tx_fifo_errors++;
+			}
+			if (txstat & TXSTATUS_LATECOLL) {
+				/* Late collision */
+				ndev->stats.tx_aborted_errors++;
+			}
+			if (txstat & TXSTATUS_EXCESSCOLL) {
+				/* Excessive collision */
+				ndev->stats.tx_aborted_errors++;
+			}
+			if (txstat & TXSTATUS_EXCESSDEFER) {
+				/* Defer limit */
+				ndev->stats.tx_aborted_errors++;
+			}
+			ndev->stats.tx_errors++;
+
+			/* Buffer transmit failed, requeue it */
+			lpc_eth_hard_start_xmit(skb, ndev);
+		} else {
+			/* Update stats */
+			ndev->stats.tx_packets++;
+			ndev->stats.tx_bytes += skb->len;
+
+			/* Free buffer */
+			dev_kfree_skb_irq(skb);
+		}
+
+		txcidx = readl(LPC_ENET_TXCONSUMEINDEX(pldat->net_base));
+	}
+
+	if (netif_queue_stopped(ndev))
+		netif_wake_queue(ndev);
+}
+
+static int __lpc_handle_recv(struct net_device *ndev, int budget)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+	struct sk_buff *skb;
+	u32 rxconsidx, len, ethst;
+	struct rx_status_t *prxstat;
+	u8 *prdbuf;
+	int rx_done = 0;
+
+	/* Get the current RX buffer indexes */
+	rxconsidx = readl(LPC_ENET_RXCONSUMEINDEX(pldat->net_base));
+	while (rx_done < budget && rxconsidx !=
+			readl(LPC_ENET_RXPRODUCEINDEX(pldat->net_base))) {
+		/* Get pointer to receive status */
+		prxstat = pldat->rx_stat_v[rxconsidx];
+		len = (prxstat->statusinfo & RXSTATUS_SIZE) + 1;
+
+		/* Status error? */
+		ethst = prxstat->statusinfo;
+		if ((ethst & (RXSTATUS_ERROR | RXSTATUS_STATUS_ERROR)) ==
+				(RXSTATUS_ERROR | RXSTATUS_RANGE))
+			ethst &= ~RXSTATUS_ERROR;
+
+		if (ethst & RXSTATUS_ERROR) {
+			int si = prxstat->statusinfo;
+			/* Check statuses */
+			if (si & RXSTATUS_OVERRUN) {
+				/* Overrun error */
+				ndev->stats.rx_fifo_errors++;
+			} else if (si & RXSTATUS_CRC) {
+				/* CRC error */
+				ndev->stats.rx_crc_errors++;
+			} else if (si & RXSTATUS_LENGTH) {
+				/* Length error */
+				ndev->stats.rx_length_errors++;
+			} else if (si & RXSTATUS_ERROR) {
+				/* Other error */
+				ndev->stats.rx_length_errors++;
+			}
+			ndev->stats.rx_errors++;
+		} else {
+			/* Packet is good */
+			skb = dev_alloc_skb(len + 8);
+			if (!skb)
+				ndev->stats.rx_dropped++;
+			else {
+				skb_reserve(skb, 8);
+				prdbuf = skb_put(skb, (len - 0));
+
+				/* Copy packet from buffer */
+				memcpy(prdbuf,
+					pldat->rx_buff_v[rxconsidx], len);
+
+				/* Pass to upper layer */
+				skb->protocol = eth_type_trans(skb, ndev);
+				netif_rx(skb);
+				ndev->last_rx = jiffies;
+				ndev->stats.rx_packets++;
+				ndev->stats.rx_bytes += len;
+			}
+		}
+
+		/* Increment consume index */
+		rxconsidx = rxconsidx + 1;
+		if (rxconsidx >= ENET_RX_DESC)
+			rxconsidx = 0;
+		writel((u32)rxconsidx,
+				LPC_ENET_RXCONSUMEINDEX(pldat->net_base));
+		rx_done++;
+	}
+
+	return rx_done;
+}
+
+static int lpc_eth_poll(struct napi_struct *napi, int budget)
+{
+	struct netdata_local *pldat = container_of(napi,
+			struct netdata_local, napi);
+	struct net_device *ndev = pldat->ndev;
+	unsigned long flags;
+	int rx_done = 0;
+
+	spin_lock_irqsave(&pldat->lock, flags);
+
+	__lpc_handle_xmit(ndev);
+	rx_done = __lpc_handle_recv(ndev, budget);
+
+	if (rx_done < budget) {
+		napi_complete(napi);
+		lpc_eth_enable_int(pldat->net_base);
+	}
+
+	spin_unlock_irqrestore(&pldat->lock, flags);
+
+	return rx_done;
+}
+
+static irqreturn_t __lpc_eth_interrupt(int irq, void *dev_id)
+{
+	struct net_device *ndev = dev_id;
+	struct netdata_local *pldat = netdev_priv(ndev);
+	u32 tmp;
+
+	spin_lock(&pldat->lock);
+
+	tmp = readl(LPC_ENET_INTSTATUS(pldat->net_base));
+	/* Clear interrupts */
+	writel(tmp, LPC_ENET_INTCLEAR(pldat->net_base));
+
+	if (likely(napi_schedule_prep(&pldat->napi))) {
+		lpc_eth_disable_int(pldat->net_base);
+		__napi_schedule(&pldat->napi);
+	}
+
+	spin_unlock(&pldat->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int lpc_eth_close(struct net_device *ndev)
+{
+	unsigned long flags;
+	struct netdata_local *pldat = netdev_priv(ndev);
+
+	if (netif_msg_ifdown(pldat))
+		dev_dbg(&pldat->pdev->dev, "shutting down %s\n", ndev->name);
+
+	napi_disable(&pldat->napi);
+	netif_stop_queue(ndev);
+
+	if (pldat->phy_dev)
+		phy_stop(pldat->phy_dev);
+
+	spin_lock_irqsave(&pldat->lock, flags);
+	__lpc_eth_reset(pldat);
+	netif_carrier_off(ndev);
+	writel(0, LPC_ENET_MAC1(pldat->net_base));
+	writel(0, LPC_ENET_MAC2(pldat->net_base));
+	spin_unlock_irqrestore(&pldat->lock, flags);
+
+	__lpc_eth_clock_enable(pldat, 0);
+
+	return 0;
+}
+
+static int lpc_eth_hard_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+	u32 len, txidx;
+	u32 *ptxstat;
+	struct txrx_desc_t *ptxrxdesc;
+
+	len = skb->len;
+
+	spin_lock_irq(&pldat->lock);
+
+	if (pldat->num_used_tx_buffs >= (ENET_TX_DESC - 1)) {
+		/* This function should never be called when there are no
+		   buffers, log the error */
+		netif_stop_queue(ndev);
+		spin_unlock_irq(&pldat->lock);
+		dev_err(&pldat->pdev->dev,
+			"BUG! TX request when no free TX buffers!\n");
+		return 1;
+	}
+
+	/* Get the next TX descriptor index */
+	txidx = readl(LPC_ENET_TXPRODUCEINDEX(pldat->net_base));
+
+	/* Setup control for the transfer */
+	ptxstat = pldat->tx_stat_v[txidx];
+	*ptxstat = 0;
+	ptxrxdesc = pldat->tx_desc_v[txidx];
+	ptxrxdesc->control =
+		(len - 1) | TXDESC_CONTROL_LAST | TXDESC_CONTROL_INT;
+
+	/* Copy data to the DMA buffer */
+	memcpy(pldat->tx_buff_v[txidx], skb->data, len);
+
+	/* Save the buffer and increment the buffer counter */
+	pldat->skb[txidx] = skb;
+	pldat->num_used_tx_buffs++;
+
+	/* Start transmit */
+	txidx++;
+	if (txidx >= ENET_TX_DESC)
+		txidx = 0;
+	writel(txidx, LPC_ENET_TXPRODUCEINDEX(pldat->net_base));
+
+	/* Stop queue if no more TX buffers */
+	if (pldat->num_used_tx_buffs >= (ENET_TX_DESC - 1))
+		netif_stop_queue(ndev);
+
+	spin_unlock_irq(&pldat->lock);
+	ndev->trans_start = jiffies;
+
+	return 0;
+}
+
+static void lpc_eth_timeout(struct net_device *ndev)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+
+	/* This should never happen and indicates a problem */
+	dev_err(&pldat->pdev->dev, "BUG! TX timeout occurred!\n");
+}
+
+static int lpc_set_mac_address(struct net_device *ndev, void *p)
+{
+	struct sockaddr *addr = p;
+	struct netdata_local *pldat = netdev_priv(ndev);
+	unsigned long flags;
+
+	if (!is_valid_ether_addr(addr->sa_data))
+		return -EADDRNOTAVAIL;
+	memcpy(ndev->dev_addr, addr->sa_data, ETH_ALEN);
+
+	spin_lock_irqsave(&pldat->lock, flags);
+
+	/* Set station address */
+	__lpc_set_mac(pldat, ndev->dev_addr);
+
+	spin_unlock_irqrestore(&pldat->lock, flags);
+
+	return 0;
+}
+
+static void lpc_eth_set_multicast_list(struct net_device *ndev)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+	struct netdev_hw_addr_list *mcptr = &ndev->mc;
+	struct netdev_hw_addr *ha;
+	u32 tmp32, hash_val, hashlo, hashhi;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pldat->lock, flags);
+
+	/* Set station address */
+	__lpc_set_mac(pldat, ndev->dev_addr);
+
+	tmp32 =  LPC_RXFLTRW_ACCEPTUBROADCAST | LPC_RXFLTRW_ACCEPTPERFECT;
+
+	if (ndev->flags & IFF_PROMISC)
+		tmp32 |= LPC_RXFLTRW_ACCEPTUNICAST |
+			LPC_RXFLTRW_ACCEPTUMULTICAST;
+	if (ndev->flags & IFF_ALLMULTI)
+		tmp32 |= LPC_RXFLTRW_ACCEPTUMULTICAST;
+
+	if (netdev_hw_addr_list_count(mcptr))
+		tmp32 |= LPC_RXFLTRW_ACCEPTUMULTICASTHASH;
+
+	writel(tmp32, LPC_ENET_RXFILTER_CTRL(pldat->net_base));
+
+
+	/* Set initial hash table */
+	hashlo = 0x0;
+	hashhi = 0x0;
+
+	/* 64 bits : multicast address in hash table */
+	netdev_hw_addr_list_for_each(ha, mcptr) {
+		hash_val = (ether_crc(6, ha->addr) >> 23) & 0x3F;
+
+		if (hash_val >= 32)
+			hashhi |= 1 << (hash_val - 32);
+		else
+			hashlo |= 1 << hash_val;
+	}
+
+	writel(hashlo, LPC_ENET_HASHFILTERL(pldat->net_base));
+	writel(hashhi, LPC_ENET_HASHFILTERH(pldat->net_base));
+
+	spin_unlock_irqrestore(&pldat->lock, flags);
+}
+
+static int lpc_eth_ioctl(struct net_device *ndev, struct ifreq *req, int cmd)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+	struct phy_device *phydev = pldat->phy_dev;
+
+	if (!netif_running(ndev))
+		return -EINVAL;
+
+	if (!phydev)
+		return -ENODEV;
+
+	return phy_mii_ioctl(phydev, req, cmd);
+}
+
+static int lpc_eth_open(struct net_device *ndev)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+
+	/* if the phy is not yet registered, retry later*/
+	if (!pldat->phy_dev)
+		return -EAGAIN;
+
+	if (netif_msg_ifup(pldat))
+		dev_dbg(&pldat->pdev->dev, "enabling %s\n", ndev->name);
+
+	if (!is_valid_ether_addr(ndev->dev_addr))
+		return -EADDRNOTAVAIL;
+
+	__lpc_eth_clock_enable(pldat, 1);
+
+	/* Reset and initialize */
+	__lpc_eth_reset(pldat);
+	__lpc_eth_init(pldat);
+
+	/* schedule a link state check */
+	phy_start(pldat->phy_dev);
+	netif_start_queue(ndev);
+	napi_enable(&pldat->napi);
+
+	return 0;
+}
+
+/*
+ * Ethtool ops
+ */
+static void lpc_eth_ethtool_getdrvinfo(struct net_device *ndev,
+	struct ethtool_drvinfo *info)
+{
+	strcpy(info->driver, MODNAME);
+	strcpy(info->version, DRV_VERSION);
+	strcpy(info->bus_info, dev_name(ndev->dev.parent));
+}
+
+static u32 lpc_eth_ethtool_getmsglevel(struct net_device *ndev)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+
+	return pldat->msg_enable;
+}
+
+static void lpc_eth_ethtool_setmsglevel(struct net_device *ndev, u32 level)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+
+	pldat->msg_enable = level;
+}
+
+static int lpc_eth_ethtool_getsettings(struct net_device *ndev,
+	struct ethtool_cmd *cmd)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+	struct phy_device *phydev = pldat->phy_dev;
+
+	if (!phydev)
+		return -ENODEV;
+
+	return phy_ethtool_gset(phydev, cmd);
+}
+
+static int lpc_eth_ethtool_setsettings(struct net_device *ndev,
+	struct ethtool_cmd *cmd)
+{
+	struct netdata_local *pldat = netdev_priv(ndev);
+	struct phy_device *phydev = pldat->phy_dev;
+
+	if (!phydev)
+		return -ENODEV;
+
+	return phy_ethtool_sset(phydev, cmd);
+}
+
+static const struct ethtool_ops lpc_eth_ethtool_ops = {
+	.get_drvinfo	= lpc_eth_ethtool_getdrvinfo,
+	.get_settings	= lpc_eth_ethtool_getsettings,
+	.set_settings	= lpc_eth_ethtool_setsettings,
+	.get_msglevel	= lpc_eth_ethtool_getmsglevel,
+	.set_msglevel	= lpc_eth_ethtool_setmsglevel,
+	.get_link	= ethtool_op_get_link,
+};
+
+static const struct net_device_ops lpc_netdev_ops = {
+	.ndo_open		= lpc_eth_open,
+	.ndo_stop		= lpc_eth_close,
+	.ndo_start_xmit		= lpc_eth_hard_start_xmit,
+	.ndo_set_rx_mode	= lpc_eth_set_multicast_list,
+	.ndo_do_ioctl		= lpc_eth_ioctl,
+	.ndo_tx_timeout		= lpc_eth_timeout,
+	.ndo_set_mac_address	= lpc_set_mac_address,
+};
+
+static int lpc_eth_drv_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct resource *dma_res;
+	struct net_device *ndev;
+	struct netdata_local *pldat;
+	struct phy_device *phydev;
+	dma_addr_t dma_handle;
+	int irq, ret;
+
+	/* Get platform resources */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dma_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	irq = platform_get_irq(pdev, 0);
+	if ((!res) || (!dma_res) || (irq < 0) || (irq >= NR_IRQS)) {
+		dev_err(&pdev->dev, "error getting resources.\n");
+		ret = -ENXIO;
+		goto err_exit;
+	}
+
+	/* Allocate net driver data structure */
+	ndev = alloc_etherdev(sizeof(struct netdata_local));
+	if (!ndev) {
+		dev_err(&pdev->dev, "could not allocate device.\n");
+		ret = -ENOMEM;
+		goto err_exit;
+	}
+
+	SET_NETDEV_DEV(ndev, &pdev->dev);
+
+	pldat = netdev_priv(ndev);
+	pldat->pdev = pdev;
+	pldat->ndev = ndev;
+
+	spin_lock_init(&pldat->lock);
+
+	/* Save resources */
+	ndev->irq = irq;
+
+	/* Get clock for the device */
+	pldat->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(pldat->clk)) {
+		dev_err(&pdev->dev, "error getting clock.\n");
+		ret = PTR_ERR(pldat->clk);
+		goto err_out_free_dev;
+	}
+
+	/* Enable network clock */
+	__lpc_eth_clock_enable(pldat, 1);
+
+	/* Map IO space */
+	pldat->net_base = ioremap(res->start, res->end - res->start + 1);
+	if (!pldat->net_base) {
+		dev_err(&pdev->dev, "failed to map registers\n");
+		ret = -ENOMEM;
+		goto err_out_disable_clocks;
+	}
+	ret = request_irq(ndev->irq, __lpc_eth_interrupt, 0,
+			  ndev->name, ndev);
+	if (ret) {
+		dev_err(&pdev->dev, "error requesting interrupt.\n");
+		goto err_out_iounmap;
+	}
+
+	/* Fill in the fields of the device structure with ethernet values. */
+	ether_setup(ndev);
+
+	/* Setup driver functions */
+	ndev->netdev_ops = &lpc_netdev_ops;
+	ndev->ethtool_ops = &lpc_eth_ethtool_ops;
+	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
+
+	/* Get size of DMA buffers/descriptors region */
+	pldat->dma_buff_size = (ENET_TX_DESC + ENET_RX_DESC) * (ENET_MAXF_SIZE +
+		sizeof(struct txrx_desc_t) + sizeof(struct rx_status_t));
+	pldat->dma_buff_base_v = 0;
+
+	if (use_iram_for_net()) {
+		dma_handle = dma_res->start;
+		if (pldat->dma_buff_size <= lpc32xx_return_iram_size())
+			pldat->dma_buff_base_v =
+				io_p2v(dma_res->start);
+		else
+			netdev_err(ndev,
+				"IRAM not big enough for net buffers, using SDRAM instead.\n");
+	}
+
+	if (pldat->dma_buff_base_v == 0) {
+		pldat->dma_buff_size = PAGE_ALIGN(pldat->dma_buff_size);
+
+		/* Allocate a chunk of memory for the DMA ethernet buffers
+		   and descriptors */
+		pldat->dma_buff_base_v =
+			dma_alloc_coherent(&pldat->pdev->dev,
+						pldat->dma_buff_size,
+						&dma_handle, GFP_KERNEL);
+
+		if (pldat->dma_buff_base_v == NULL) {
+			dev_err(&pdev->dev, "error getting DMA region.\n");
+			ret = -ENOMEM;
+			goto err_out_free_irq;
+		}
+	}
+	pldat->dma_buff_base_p = dma_handle;
+
+	netdev_dbg(ndev, "IO address start     :0x%08x\n",
+			res->start);
+	netdev_dbg(ndev, "IO address size      :%d\n",
+			res->end - res->start + 1);
+	netdev_err(ndev, "IO address (mapped)  :0x%p\n",
+			pldat->net_base);
+	netdev_dbg(ndev, "IRQ number           :%d\n", ndev->irq);
+	netdev_dbg(ndev, "DMA buffer size      :%d\n", pldat->dma_buff_size);
+	netdev_dbg(ndev, "DMA buffer P address :0x%08x\n",
+			pldat->dma_buff_base_p);
+	netdev_dbg(ndev, "DMA buffer V address :0x%p\n",
+			pldat->dma_buff_base_v);
+
+	/* Get MAC address from current HW setting (POR state is all zeros) */
+	__lpc_get_mac(pldat, ndev->dev_addr);
+
+#ifdef CONFIG_OF_NET
+	if (!is_valid_ether_addr(ndev->dev_addr)) {
+		const char *macaddr = of_get_mac_address(pdev->dev.of_node);
+		if (macaddr)
+			memcpy(ndev->dev_addr, macaddr, ETH_ALEN);
+	}
+#endif
+	if (!is_valid_ether_addr(ndev->dev_addr))
+		dev_hw_addr_random(ndev, ndev->dev_addr);
+
+	/* Reset the ethernet controller */
+	__lpc_eth_reset(pldat);
+
+	/* then shut everything down to save power */
+	__lpc_eth_shutdown(pldat);
+
+	/* Set default parameters */
+	pldat->msg_enable = NETIF_MSG_LINK;
+
+	/* Force an MII interface reset and clock setup */
+	__lpc_mii_mngt_reset(pldat);
+
+	/* Force default PHY interface setup in chip, this will probably be
+	   changed by the PHY driver */
+	pldat->link = 0;
+	pldat->speed = 100;
+	pldat->duplex = DUPLEX_FULL;
+	__lpc_params_setup(pldat);
+
+	netif_napi_add(ndev, &pldat->napi, lpc_eth_poll, NAPI_WEIGHT);
+
+	ret = register_netdev(ndev);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot register net device, aborting.\n");
+		goto err_out_dma_unmap;
+	}
+	platform_set_drvdata(pdev, ndev);
+
+	if (lpc_mii_init(pldat) != 0)
+		goto err_out_unregister_netdev;
+
+	netdev_info(ndev, "LPC mac at 0x%08x irq %d\n",
+	       res->start, ndev->irq);
+
+	phydev = pldat->phy_dev;
+	netdev_info(ndev,
+		"attached PHY driver [%s] (mii_bus:phy_addr=%s, irq=%d)\n",
+		phydev->drv->name, dev_name(&phydev->dev), phydev->irq);
+
+	device_init_wakeup(&pdev->dev, 1);
+	device_set_wakeup_enable(&pdev->dev, 0);
+
+	return 0;
+
+err_out_unregister_netdev:
+	platform_set_drvdata(pdev, NULL);
+	unregister_netdev(ndev);
+err_out_dma_unmap:
+	if (!use_iram_for_net() ||
+			pldat->dma_buff_size > lpc32xx_return_iram_size())
+		dma_free_coherent(&pldat->pdev->dev, pldat->dma_buff_size,
+			pldat->dma_buff_base_v,
+			pldat->dma_buff_base_p);
+err_out_free_irq:
+	free_irq(ndev->irq, ndev);
+err_out_iounmap:
+	iounmap(pldat->net_base);
+err_out_disable_clocks:
+	clk_disable(pldat->clk);
+	clk_put(pldat->clk);
+err_out_free_dev:
+	free_netdev(ndev);
+err_exit:
+	pr_err("%s: not found (%d).\n", MODNAME, ret);
+	return ret;
+}
+
+static int lpc_eth_drv_remove(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct netdata_local *pldat = netdev_priv(ndev);
+
+	unregister_netdev(ndev);
+	platform_set_drvdata(pdev, NULL);
+
+	if (!use_iram_for_net() ||
+			pldat->dma_buff_size > lpc32xx_return_iram_size())
+		dma_free_coherent(&pldat->pdev->dev, pldat->dma_buff_size,
+			pldat->dma_buff_base_v,
+			pldat->dma_buff_base_p);
+	free_irq(ndev->irq, ndev);
+	iounmap(pldat->net_base);
+	clk_disable(pldat->clk);
+	clk_put(pldat->clk);
+	free_netdev(ndev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int lpc_eth_drv_suspend(struct platform_device *pdev,
+	pm_message_t state)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct netdata_local *pldat = netdev_priv(ndev);
+
+	if (device_may_wakeup(&pdev->dev))
+		enable_irq_wake(ndev->irq);
+
+	if (ndev) {
+		if (netif_running(ndev)) {
+			netif_device_detach(ndev);
+			__lpc_eth_shutdown(pldat);
+			clk_disable(pldat->clk);
+
+			/*
+			 * Reset again now clock is disable to be sure
+			 * EMC_MDC is down
+			 */
+			__lpc_eth_reset(pldat);
+		}
+	}
+
+	return 0;
+}
+
+static int lpc_eth_drv_resume(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct netdata_local *pldat;
+
+	if (device_may_wakeup(&pdev->dev))
+		disable_irq_wake(ndev->irq);
+
+	if (ndev) {
+		if (netif_running(ndev)) {
+			pldat = netdev_priv(ndev);
+
+			/* Enable interface clock */
+			clk_enable(pldat->clk);
+
+			/* Reset and initialize */
+			__lpc_eth_reset(pldat);
+			__lpc_eth_init(pldat);
+
+			netif_device_attach(ndev);
+		}
+	}
+
+	return 0;
+}
+#endif
+
+static struct platform_driver lpc_eth_driver = {
+	.probe		= lpc_eth_drv_probe,
+	.remove		= __devexit_p(lpc_eth_drv_remove),
+#ifdef CONFIG_PM
+	.suspend	= lpc_eth_drv_suspend,
+	.resume		= lpc_eth_drv_resume,
+#endif
+	.driver		= {
+		.name	= MODNAME,
+	},
+};
+
+module_platform_driver(lpc_eth_driver);
+
+MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
+MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
+MODULE_DESCRIPTION("LPC Ethernet Driver");
+MODULE_LICENSE("GPL");
+

Re: [PATCH v4] lpc32xx: Added ethernet driver

[Ben Hutchings]

On Mon, 2012-03-05 at 22:40 +0100, Roland Stigge wrote:
[...]
> --- /dev/null
> +++ linux-2.6/drivers/net/ethernet/nxp/lpc_eth.c
[...]
> +/*
> + * Transmit timeout, default 2.5 seconds.
> + */
> +static int watchdog = 2500;
> +module_param(watchdog, int, 0400);
> +MODULE_PARM_DESC(watchdog, "transmit timeout in milliseconds");

Why does this need to be a parameter?

> +/*
> + * Structure of a TX/RX descriptors and RX status
> + */
> +struct txrx_desc_t {
> +	volatile u32 packet;
> +	volatile u32 control;
> +};
> +struct rx_status_t {
> +	volatile u32 statusinfo;
> +	volatile u32 statushashcrc;
> +};

Use of volatile here is probably wrong; see
Documentation/volatile-considered-harmful.txt.

> +/*
> + * Device driver data structure
> + */
> +struct netdata_local {
> +	struct platform_device	*pdev;
> +	struct net_device	*ndev;
> +	spinlock_t		lock;
> +	void __iomem		*net_base;
> +	u32			msg_enable;
> +	struct sk_buff		*skb[ENET_TX_DESC];
> +	unsigned int		last_tx_idx;
> +	unsigned int		num_used_tx_buffs;
> +	struct mii_bus		*mii_bus;
> +	struct phy_device	*phy_dev;
> +	struct clk		*clk;
> +	dma_addr_t		dma_buff_base_p;
> +	void			*dma_buff_base_v;
> +	size_t			dma_buff_size;
> +	struct txrx_desc_t	*tx_desc_v[ENET_TX_DESC];
> +	u32			*tx_stat_v[ENET_TX_DESC];
> +	void			*tx_buff_v[ENET_TX_DESC];
> +	struct txrx_desc_t	*rx_desc_v[ENET_RX_DESC];
> +	struct rx_status_t	*rx_stat_v[ENET_RX_DESC];
> +	void			*rx_buff_v[ENET_RX_DESC];

Why are these 6 members defined as arrays of pointers and not single
pointers to arrays?  It appears that each array element is initialised
to point into an array and then never changed; for example
tx_desc_v[i] == tx_desc_v[0] + i.

[...]
> +static void __lpc_eth_init(struct netdata_local *pldat)
> +{
[...]
> +	/* Clear and enable interrupts */
> +	writel(0xFFFF, LPC_ENET_INTCLEAR(pldat->net_base));
> +	lpc_eth_enable_int(pldat->net_base);
> +
> +	/* Get the next TX buffer output index */
> +	pldat->num_used_tx_buffs = 0;
> +	pldat->last_tx_idx =
> +		readl(LPC_ENET_TXCONSUMEINDEX(pldat->net_base));

Doesn't this need to be done *before* enabling interrupts?  Also, I
think you need an smp_wmb() so that the interrupt handler is guaranteed
to see all these writes.

[...]
> +static void lpc_handle_link_change(struct net_device *ndev)
> +{
> +	struct netdata_local *pldat = netdev_priv(ndev);
> +	struct phy_device *phydev = pldat->phy_dev;
> +	unsigned long flags;
> +
> +	int status_change = 0;

This is logically a boolean, so use bool/true/false.

[...]
> +static void __lpc_handle_xmit(struct net_device *ndev)
> +{
[...]
> +		/* Any errors occurred? */
> +		if (txstat & TXSTATUS_ERROR) {
> +			if (txstat & TXSTATUS_UNDERRUN) {
> +				/* FIFO underrun */
> +				ndev->stats.tx_fifo_errors++;
> +			}
> +			if (txstat & TXSTATUS_LATECOLL) {
> +				/* Late collision */
> +				ndev->stats.tx_aborted_errors++;
> +			}
> +			if (txstat & TXSTATUS_EXCESSCOLL) {
> +				/* Excessive collision */
> +				ndev->stats.tx_aborted_errors++;
> +			}
> +			if (txstat & TXSTATUS_EXCESSDEFER) {
> +				/* Defer limit */
> +				ndev->stats.tx_aborted_errors++;
> +			}
> +			ndev->stats.tx_errors++;
> +
> +			/* Buffer transmit failed, requeue it */
> +			lpc_eth_hard_start_xmit(skb, ndev);

It is not the responsibility of an Ethernet network driver to retry
transmission.  Also, this will deadlock on an SMP system since
lpc_eth_hard_start_xmit() will try to acquire pldat->lock which is
already held.  I suggest you test with lockdep in case there any other
such bugs which are being masked by running on a UP system.

[...]
> +static int __lpc_handle_recv(struct net_device *ndev, int budget)
> +{
[...]
> +			/* Packet is good */
> +			skb = dev_alloc_skb(len + 8);
> +			if (!skb)
> +				ndev->stats.rx_dropped++;
> +			else {
> +				skb_reserve(skb, 8);

What are you reserving this space for?

> +				prdbuf = skb_put(skb, (len - 0));

len - 0??

> +				/* Copy packet from buffer */
> +				memcpy(prdbuf,
> +					pldat->rx_buff_v[rxconsidx], len);
> +
> +				/* Pass to upper layer */
> +				skb->protocol = eth_type_trans(skb, ndev);
> +				netif_rx(skb);
> +				ndev->last_rx = jiffies;

Drivers don't need to set last_rx any more.

[...]
> +static int lpc_eth_poll(struct napi_struct *napi, int budget)
> +{
> +	struct netdata_local *pldat = container_of(napi,
> +			struct netdata_local, napi);
> +	struct net_device *ndev = pldat->ndev;
> +	unsigned long flags;
> +	int rx_done = 0;
> +
> +	spin_lock_irqsave(&pldat->lock, flags);
> +
> +	__lpc_handle_xmit(ndev);
> +	rx_done = __lpc_handle_recv(ndev, budget);
> +
> +	if (rx_done < budget) {
> +		napi_complete(napi);
> +		lpc_eth_enable_int(pldat->net_base);
> +	}
> +
> +	spin_unlock_irqrestore(&pldat->lock, flags);

This is really sad.  You implement NAPI but then take away most of the
benefits of that by disabling interrupts.

It looks like you could safely unlock pldat->lock before calling
__lpc_handle_recv - nothing else manipulates RX queue state so no lock
is required.

As for the TX side, you can probably use the TX queue lock
(__netif_tx_lock, __netif_tx_unlock) to serialise with
lpc_eth_hard_start_xmit() and avoid taking pldat->lock in either
__lpc_handle_xmit() or here.

[...]
> +	return rx_done;
> +}
> +
> +static irqreturn_t __lpc_eth_interrupt(int irq, void *dev_id)
> +{
> +	struct net_device *ndev = dev_id;
> +	struct netdata_local *pldat = netdev_priv(ndev);
> +	u32 tmp;
> +
> +	spin_lock(&pldat->lock);
> +
> +	tmp = readl(LPC_ENET_INTSTATUS(pldat->net_base));
> +	/* Clear interrupts */
> +	writel(tmp, LPC_ENET_INTCLEAR(pldat->net_base));
> +
> +	if (likely(napi_schedule_prep(&pldat->napi))) {
> +		lpc_eth_disable_int(pldat->net_base);
> +		__napi_schedule(&pldat->napi);
> +	}

I think you need to mask the interrupt unconditionally here.  See my
next comment.

> +	spin_unlock(&pldat->lock);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int lpc_eth_close(struct net_device *ndev)
> +{
> +	unsigned long flags;
> +	struct netdata_local *pldat = netdev_priv(ndev);
> +
> +	if (netif_msg_ifdown(pldat))
> +		dev_dbg(&pldat->pdev->dev, "shutting down %s\n", ndev->name);
> +
> +	napi_disable(&pldat->napi);

If an interrupt is received after this returns, napi_schedule_prep()
will return false and the interrupt will not be masked.

There is a similar problem in lpc_eth_open() where you enable interrupts
before NAPI.

> +	netif_stop_queue(ndev);
> +
> +	if (pldat->phy_dev)
> +		phy_stop(pldat->phy_dev);
> +
> +	spin_lock_irqsave(&pldat->lock, flags);
> +	__lpc_eth_reset(pldat);
> +	netif_carrier_off(ndev);
> +	writel(0, LPC_ENET_MAC1(pldat->net_base));
> +	writel(0, LPC_ENET_MAC2(pldat->net_base));
> +	spin_unlock_irqrestore(&pldat->lock, flags);
> +
> +	__lpc_eth_clock_enable(pldat, 0);
> +
> +	return 0;
> +}
[...]
> +static int lpc_eth_hard_start_xmit(struct sk_buff *skb, struct net_device *ndev)
> +{
> +	struct netdata_local *pldat = netdev_priv(ndev);
> +	u32 len, txidx;
> +	u32 *ptxstat;
> +	struct txrx_desc_t *ptxrxdesc;
> +
> +	len = skb->len;
> +
> +	spin_lock_irq(&pldat->lock);
> +
> +	if (pldat->num_used_tx_buffs >= (ENET_TX_DESC - 1)) {
> +		/* This function should never be called when there are no
> +		   buffers, log the error */

So use WARN to make the error really obvious.

> +		netif_stop_queue(ndev);
> +		spin_unlock_irq(&pldat->lock);
> +		dev_err(&pldat->pdev->dev,
> +			"BUG! TX request when no free TX buffers!\n");
> +		return 1;

This is not a valid return value; you need to return NETDEV_TX_BUSY.

> +	}
> +
> +	/* Get the next TX descriptor index */
> +	txidx = readl(LPC_ENET_TXPRODUCEINDEX(pldat->net_base));
> +
> +	/* Setup control for the transfer */
> +	ptxstat = pldat->tx_stat_v[txidx];
> +	*ptxstat = 0;
> +	ptxrxdesc = pldat->tx_desc_v[txidx];
> +	ptxrxdesc->control =
> +		(len - 1) | TXDESC_CONTROL_LAST | TXDESC_CONTROL_INT;
> +
> +	/* Copy data to the DMA buffer */
> +	memcpy(pldat->tx_buff_v[txidx], skb->data, len);
> +
> +	/* Save the buffer and increment the buffer counter */
> +	pldat->skb[txidx] = skb;
> +	pldat->num_used_tx_buffs++;
> +
> +	/* Start transmit */
> +	txidx++;
> +	if (txidx >= ENET_TX_DESC)
> +		txidx = 0;
> +	writel(txidx, LPC_ENET_TXPRODUCEINDEX(pldat->net_base));
> +
> +	/* Stop queue if no more TX buffers */
> +	if (pldat->num_used_tx_buffs >= (ENET_TX_DESC - 1))
> +		netif_stop_queue(ndev);
> +
> +	spin_unlock_irq(&pldat->lock);
> +	ndev->trans_start = jiffies;

Drivers don't need to set trans_start any more.

> +	return 0;

NETDEV_TX_OK

> +}
[...]
> +static void lpc_eth_timeout(struct net_device *ndev)
> +{
> +	struct netdata_local *pldat = netdev_priv(ndev);
> +
> +	/* This should never happen and indicates a problem */
> +	dev_err(&pldat->pdev->dev, "BUG! TX timeout occurred!\n");
> +}

The networking core will print a big fat warning before calling this
function, so this message is redundant.  Also, timeout isn't necessarily
a bug; it can be caused by a misconfigured switch.

[...]
> +static int lpc_eth_ethtool_getsettings(struct net_device *ndev,
> +	struct ethtool_cmd *cmd)
> +{
> +	struct netdata_local *pldat = netdev_priv(ndev);
> +	struct phy_device *phydev = pldat->phy_dev;
> +
> +	if (!phydev)
> +		return -ENODEV;

-EOPNOTSUPP

> +	return phy_ethtool_gset(phydev, cmd);
> +}
> +
> +static int lpc_eth_ethtool_setsettings(struct net_device *ndev,
> +	struct ethtool_cmd *cmd)
> +{
> +	struct netdata_local *pldat = netdev_priv(ndev);
> +	struct phy_device *phydev = pldat->phy_dev;
> +
> +	if (!phydev)
> +		return -ENODEV;
[...]

-EOPNOTSUPP

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Re: [PATCH v4] lpc32xx: Added ethernet driver

[Eric Dumazet]

On Mon, 2012-03-05 at 22:45 +0000, Ben Hutchings wrote:
> On Mon, 2012-03-05 at 22:40 +0100, Roland Stigge wrote:
> [...]

...

> > +				/* Copy packet from buffer */
> > +				memcpy(prdbuf,
> > +					pldat->rx_buff_v[rxconsidx], len);
> > +
> > +				/* Pass to upper layer */
> > +				skb->protocol = eth_type_trans(skb, ndev);
> > +				netif_rx(skb);
> > +				ndev->last_rx = jiffies;
> 
> Drivers don't need to set last_rx any more.

Also, a NAPI driver should call netif_receive_skb() instead of
netif_rx()

netif_rx() is more expensive because of additional queue, while
netif_receive_skb() directly calls the upper stacks.

Re: [PATCH v4] lpc32xx: Added ethernet driver

[Ben Hutchings]

On Mon, 2012-03-05 at 16:49 -0800, Eric Dumazet wrote:
> On Mon, 2012-03-05 at 22:45 +0000, Ben Hutchings wrote:
> > On Mon, 2012-03-05 at 22:40 +0100, Roland Stigge wrote:
> > [...]
> 
> ...
> 
> > > +				/* Copy packet from buffer */
> > > +				memcpy(prdbuf,
> > > +					pldat->rx_buff_v[rxconsidx], len);
> > > +
> > > +				/* Pass to upper layer */
> > > +				skb->protocol = eth_type_trans(skb, ndev);
> > > +				netif_rx(skb);
> > > +				ndev->last_rx = jiffies;
> > 
> > Drivers don't need to set last_rx any more.
> 
> Also, a NAPI driver should call netif_receive_skb() instead of
> netif_rx()
> 
> netif_rx() is more expensive because of additional queue, while
> netif_receive_skb() directly calls the upper stacks.

Yes, but not until the poll function is changed to enable IRQs.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Re: [PATCH v4] lpc32xx: Added ethernet driver

[Roland Stigge]

Hi Ben,

thank you for your review!

On 03/05/2012 11:45 PM, Ben Hutchings wrote:
> [...]
>> +static int lpc_eth_poll(struct napi_struct *napi, int budget)
>> +{
>> +	struct netdata_local *pldat = container_of(napi,
>> +			struct netdata_local, napi);
>> +	struct net_device *ndev = pldat->ndev;
>> +	unsigned long flags;
>> +	int rx_done = 0;
>> +
>> +	spin_lock_irqsave(&pldat->lock, flags);
>> +
>> +	__lpc_handle_xmit(ndev);
>> +	rx_done = __lpc_handle_recv(ndev, budget);
>> +
>> +	if (rx_done < budget) {
>> +		napi_complete(napi);
>> +		lpc_eth_enable_int(pldat->net_base);
>> +	}
>> +
>> +	spin_unlock_irqrestore(&pldat->lock, flags);
>
> This is really sad.  You implement NAPI but then take away most of the
> benefits of that by disabling interrupts.
>
> It looks like you could safely unlock pldat->lock before calling
> __lpc_handle_recv - nothing else manipulates RX queue state so no lock
> is required.
>
> As for the TX side, you can probably use the TX queue lock
> (__netif_tx_lock, __netif_tx_unlock) to serialise with
> lpc_eth_hard_start_xmit() and avoid taking pldat->lock in either
> __lpc_handle_xmit() or here.

Sounds reasonable, and will do it.

However, I implemented it from the example of
drivers/net/ethernet/via/via-velocity.c:velocity_poll() - is there a
good reason for doing it that way in the velocity driver or is it done
incorrectly there, also?

Thanks,

Roland

Re: [PATCH v4] lpc32xx: Added ethernet driver

[Eric Dumazet]

Le mardi 06 mars 2012 à 09:53 +0100, Roland Stigge a écrit :

> Sounds reasonable, and will do it.
> 
> However, I implemented it from the example of
> drivers/net/ethernet/via/via-velocity.c:velocity_poll() - is there a
> good reason for doing it that way in the velocity driver or is it done
> incorrectly there, also?
> 

Its done in a non efficient way.

It works as is, but its not the right thing to do.
The NAPI port was very minimal on via-velocity it seems.

A better way is to hold no locks in the RX handler, allowing calls to
netif_receive_skb() [ and potential calls to xmit while handling this
incoming skbs ]

Problem of saying "we dont expect to be SMP anyway", is that this let
reference material for future drivers that will copy/paste the code,
then experience performance problems.

Re: [PATCH v4] lpc32xx: Added ethernet driver: smp_wmb()

[Roland Stigge]

On 03/05/2012 11:45 PM, Ben Hutchings wrote:
>> +	/* Clear and enable interrupts */
>> +	writel(0xFFFF, LPC_ENET_INTCLEAR(pldat->net_base));
>> +	lpc_eth_enable_int(pldat->net_base);
>> +
>> +	/* Get the next TX buffer output index */
>> +	pldat->num_used_tx_buffs = 0;
>> +	pldat->last_tx_idx =
>> +		readl(LPC_ENET_TXCONSUMEINDEX(pldat->net_base));
> 
> Doesn't this need to be done *before* enabling interrupts?  Also, I
> think you need an smp_wmb() so that the interrupt handler is guaranteed
> to see all these writes.

Do you mean _one_ smp_wmb() directly after lpc_eth_enable_int() (which
I'm moving behind the above code?

Note that there is no SMP in LPCs and NXP is not planning to build one
AFAIK. However, I'm fine with including smp_wmb() anyway for completeness.

Thanks in advance,

Roland

Re: [PATCH v4] lpc32xx: Added ethernet driver: smp_wmb()

[Ben Hutchings]

On Tue, 2012-03-06 at 11:43 +0100, Roland Stigge wrote:
> On 03/05/2012 11:45 PM, Ben Hutchings wrote:
> >> +	/* Clear and enable interrupts */
> >> +	writel(0xFFFF, LPC_ENET_INTCLEAR(pldat->net_base));
> >> +	lpc_eth_enable_int(pldat->net_base);
> >> +
> >> +	/* Get the next TX buffer output index */
> >> +	pldat->num_used_tx_buffs = 0;
> >> +	pldat->last_tx_idx =
> >> +		readl(LPC_ENET_TXCONSUMEINDEX(pldat->net_base));
> > 
> > Doesn't this need to be done *before* enabling interrupts?  Also, I
> > think you need an smp_wmb() so that the interrupt handler is guaranteed
> > to see all these writes.
> 
> Do you mean _one_ smp_wmb() directly after lpc_eth_enable_int() (which
> I'm moving behind the above code?

The sequence should be

	pldat->state = values...;
	smp_wmb();
	enable_interrupts();

> Note that there is no SMP in LPCs and NXP is not planning to build one
> AFAIK.

Never say never!

> However, I'm fine with including smp_wmb() anyway for completeness.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Re: [PATCH v4] lpc32xx: Added ethernet driver: smp_wmb()

[Russell King - ARM Linux]

On Tue, Mar 06, 2012 at 02:03:28PM +0000, Ben Hutchings wrote:
> On Tue, 2012-03-06 at 11:43 +0100, Roland Stigge wrote:
> > On 03/05/2012 11:45 PM, Ben Hutchings wrote:
> > >> +	/* Clear and enable interrupts */
> > >> +	writel(0xFFFF, LPC_ENET_INTCLEAR(pldat->net_base));
> > >> +	lpc_eth_enable_int(pldat->net_base);
> > >> +
> > >> +	/* Get the next TX buffer output index */
> > >> +	pldat->num_used_tx_buffs = 0;
> > >> +	pldat->last_tx_idx =
> > >> +		readl(LPC_ENET_TXCONSUMEINDEX(pldat->net_base));
> > > 
> > > Doesn't this need to be done *before* enabling interrupts?  Also, I
> > > think you need an smp_wmb() so that the interrupt handler is guaranteed
> > > to see all these writes.
> > 
> > Do you mean _one_ smp_wmb() directly after lpc_eth_enable_int() (which
> > I'm moving behind the above code?
> 
> The sequence should be
> 
> 	pldat->state = values...;
> 	smp_wmb();
> 	enable_interrupts();

Is this correct?

"SMP BARRIER PAIRING" and "EXAMPLES OF MEMORY BARRIER SEQUENCES" in
Documentation/memory-barriers.txt suggest that there should be some kind
of pairing with smp_wmb() to ensure correctness.

Re: [PATCH v4] lpc32xx: Added ethernet driver: smp_wmb()

[Ben Hutchings]

On Tue, 2012-03-06 at 14:17 +0000, Russell King - ARM Linux wrote:
> On Tue, Mar 06, 2012 at 02:03:28PM +0000, Ben Hutchings wrote:
> > On Tue, 2012-03-06 at 11:43 +0100, Roland Stigge wrote:
> > > On 03/05/2012 11:45 PM, Ben Hutchings wrote:
> > > >> +	/* Clear and enable interrupts */
> > > >> +	writel(0xFFFF, LPC_ENET_INTCLEAR(pldat->net_base));
> > > >> +	lpc_eth_enable_int(pldat->net_base);
> > > >> +
> > > >> +	/* Get the next TX buffer output index */
> > > >> +	pldat->num_used_tx_buffs = 0;
> > > >> +	pldat->last_tx_idx =
> > > >> +		readl(LPC_ENET_TXCONSUMEINDEX(pldat->net_base));
> > > > 
> > > > Doesn't this need to be done *before* enabling interrupts?  Also, I
> > > > think you need an smp_wmb() so that the interrupt handler is guaranteed
> > > > to see all these writes.
> > > 
> > > Do you mean _one_ smp_wmb() directly after lpc_eth_enable_int() (which
> > > I'm moving behind the above code?
> > 
> > The sequence should be
> > 
> > 	pldat->state = values...;
> > 	smp_wmb();
> > 	enable_interrupts();
> 
> Is this correct?
> 
> "SMP BARRIER PAIRING" and "EXAMPLES OF MEMORY BARRIER SEQUENCES" in
> Documentation/memory-barriers.txt suggest that there should be some kind
> of pairing with smp_wmb() to ensure correctness.

The thread we're synchronising with (the interrupt handler) starts
*after* the smp_wmb().  Therefore there is no need for a second barrier.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.