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tegrakernel/kernel/kernel-4.9/drivers/net/ethernet/xilinx/xilinx_emaclite.c

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initial commit tegra kernel 32.6.1
2022-02-16 09:13:02 -06:00
/*
* Xilinx EmacLite Linux driver for the Xilinx Ethernet MAC Lite device.
*
* This is a new flat driver which is based on the original emac_lite
* driver from John Williams <john.williams@xilinx.com>.
*
* 2007 - 2013 (c) Xilinx, Inc.
*
* 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.
*/
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/phy.h>
#include <linux/interrupt.h>
#define DRIVER_NAME "xilinx_emaclite"
/* Register offsets for the EmacLite Core */
#define XEL_TXBUFF_OFFSET 0x0 /* Transmit Buffer */
#define XEL_MDIOADDR_OFFSET 0x07E4 /* MDIO Address Register */
#define XEL_MDIOWR_OFFSET 0x07E8 /* MDIO Write Data Register */
#define XEL_MDIORD_OFFSET 0x07EC /* MDIO Read Data Register */
#define XEL_MDIOCTRL_OFFSET 0x07F0 /* MDIO Control Register */
#define XEL_GIER_OFFSET 0x07F8 /* GIE Register */
#define XEL_TSR_OFFSET 0x07FC /* Tx status */
#define XEL_TPLR_OFFSET 0x07F4 /* Tx packet length */
#define XEL_RXBUFF_OFFSET 0x1000 /* Receive Buffer */
#define XEL_RPLR_OFFSET 0x100C /* Rx packet length */
#define XEL_RSR_OFFSET 0x17FC /* Rx status */
#define XEL_BUFFER_OFFSET 0x0800 /* Next Tx/Rx buffer's offset */
/* MDIO Address Register Bit Masks */
#define XEL_MDIOADDR_REGADR_MASK 0x0000001F /* Register Address */
#define XEL_MDIOADDR_PHYADR_MASK 0x000003E0 /* PHY Address */
#define XEL_MDIOADDR_PHYADR_SHIFT 5
#define XEL_MDIOADDR_OP_MASK 0x00000400 /* RD/WR Operation */
/* MDIO Write Data Register Bit Masks */
#define XEL_MDIOWR_WRDATA_MASK 0x0000FFFF /* Data to be Written */
/* MDIO Read Data Register Bit Masks */
#define XEL_MDIORD_RDDATA_MASK 0x0000FFFF /* Data to be Read */
/* MDIO Control Register Bit Masks */
#define XEL_MDIOCTRL_MDIOSTS_MASK 0x00000001 /* MDIO Status Mask */
#define XEL_MDIOCTRL_MDIOEN_MASK 0x00000008 /* MDIO Enable */
/* Global Interrupt Enable Register (GIER) Bit Masks */
#define XEL_GIER_GIE_MASK 0x80000000 /* Global Enable */
/* Transmit Status Register (TSR) Bit Masks */
#define XEL_TSR_XMIT_BUSY_MASK 0x00000001 /* Tx complete */
#define XEL_TSR_PROGRAM_MASK 0x00000002 /* Program the MAC address */
#define XEL_TSR_XMIT_IE_MASK 0x00000008 /* Tx interrupt enable bit */
#define XEL_TSR_XMIT_ACTIVE_MASK 0x80000000 /* Buffer is active, SW bit
* only. This is not documented
* in the HW spec */
/* Define for programming the MAC address into the EmacLite */
#define XEL_TSR_PROG_MAC_ADDR (XEL_TSR_XMIT_BUSY_MASK | XEL_TSR_PROGRAM_MASK)
/* Receive Status Register (RSR) */
#define XEL_RSR_RECV_DONE_MASK 0x00000001 /* Rx complete */
#define XEL_RSR_RECV_IE_MASK 0x00000008 /* Rx interrupt enable bit */
/* Transmit Packet Length Register (TPLR) */
#define XEL_TPLR_LENGTH_MASK 0x0000FFFF /* Tx packet length */
/* Receive Packet Length Register (RPLR) */
#define XEL_RPLR_LENGTH_MASK 0x0000FFFF /* Rx packet length */
#define XEL_HEADER_OFFSET 12 /* Offset to length field */
#define XEL_HEADER_SHIFT 16 /* Shift value for length */
/* General Ethernet Definitions */
#define XEL_ARP_PACKET_SIZE 28 /* Max ARP packet size */
#define XEL_HEADER_IP_LENGTH_OFFSET 16 /* IP Length Offset */
#define TX_TIMEOUT (60*HZ) /* Tx timeout is 60 seconds. */
#define ALIGNMENT 4
/* BUFFER_ALIGN(adr) calculates the number of bytes to the next alignment. */
#define BUFFER_ALIGN(adr) ((ALIGNMENT - ((u32) adr)) % ALIGNMENT)
#ifdef __BIG_ENDIAN
#define xemaclite_readl ioread32be
#define xemaclite_writel iowrite32be
#else
#define xemaclite_readl ioread32
#define xemaclite_writel iowrite32
#endif
/**
* struct net_local - Our private per device data
* @ndev: instance of the network device
* @tx_ping_pong: indicates whether Tx Pong buffer is configured in HW
* @rx_ping_pong: indicates whether Rx Pong buffer is configured in HW
* @next_tx_buf_to_use: next Tx buffer to write to
* @next_rx_buf_to_use: next Rx buffer to read from
* @base_addr: base address of the Emaclite device
* @reset_lock: lock used for synchronization
* @deferred_skb: holds an skb (for transmission at a later time) when the
* Tx buffer is not free
* @phy_dev: pointer to the PHY device
* @phy_node: pointer to the PHY device node
* @mii_bus: pointer to the MII bus
* @last_link: last link status
* @has_mdio: indicates whether MDIO is included in the HW
*/
struct net_local {
struct net_device *ndev;
bool tx_ping_pong;
bool rx_ping_pong;
u32 next_tx_buf_to_use;
u32 next_rx_buf_to_use;
void __iomem *base_addr;
spinlock_t reset_lock;
struct sk_buff *deferred_skb;
struct phy_device *phy_dev;
struct device_node *phy_node;
struct mii_bus *mii_bus;
int last_link;
bool has_mdio;
};
/*************************/
/* EmacLite driver calls */
/*************************/
/**
* xemaclite_enable_interrupts - Enable the interrupts for the EmacLite device
* @drvdata: Pointer to the Emaclite device private data
*
* This function enables the Tx and Rx interrupts for the Emaclite device along
* with the Global Interrupt Enable.
*/
static void xemaclite_enable_interrupts(struct net_local *drvdata)
{
u32 reg_data;
/* Enable the Tx interrupts for the first Buffer */
reg_data = xemaclite_readl(drvdata->base_addr + XEL_TSR_OFFSET);
xemaclite_writel(reg_data | XEL_TSR_XMIT_IE_MASK,
drvdata->base_addr + XEL_TSR_OFFSET);
/* Enable the Rx interrupts for the first buffer */
xemaclite_writel(XEL_RSR_RECV_IE_MASK, drvdata->base_addr + XEL_RSR_OFFSET);
/* Enable the Global Interrupt Enable */
xemaclite_writel(XEL_GIER_GIE_MASK, drvdata->base_addr + XEL_GIER_OFFSET);
}
/**
* xemaclite_disable_interrupts - Disable the interrupts for the EmacLite device
* @drvdata: Pointer to the Emaclite device private data
*
* This function disables the Tx and Rx interrupts for the Emaclite device,
* along with the Global Interrupt Enable.
*/
static void xemaclite_disable_interrupts(struct net_local *drvdata)
{
u32 reg_data;
/* Disable the Global Interrupt Enable */
xemaclite_writel(XEL_GIER_GIE_MASK, drvdata->base_addr + XEL_GIER_OFFSET);
/* Disable the Tx interrupts for the first buffer */
reg_data = xemaclite_readl(drvdata->base_addr + XEL_TSR_OFFSET);
xemaclite_writel(reg_data & (~XEL_TSR_XMIT_IE_MASK),
drvdata->base_addr + XEL_TSR_OFFSET);
/* Disable the Rx interrupts for the first buffer */
reg_data = xemaclite_readl(drvdata->base_addr + XEL_RSR_OFFSET);
xemaclite_writel(reg_data & (~XEL_RSR_RECV_IE_MASK),
drvdata->base_addr + XEL_RSR_OFFSET);
}
/**
* xemaclite_aligned_write - Write from 16-bit aligned to 32-bit aligned address
* @src_ptr: Void pointer to the 16-bit aligned source address
* @dest_ptr: Pointer to the 32-bit aligned destination address
* @length: Number bytes to write from source to destination
*
* This function writes data from a 16-bit aligned buffer to a 32-bit aligned
* address in the EmacLite device.
*/
static void xemaclite_aligned_write(void *src_ptr, u32 *dest_ptr,
unsigned length)
{
u32 align_buffer;
u32 *to_u32_ptr;
u16 *from_u16_ptr, *to_u16_ptr;
to_u32_ptr = dest_ptr;
from_u16_ptr = src_ptr;
align_buffer = 0;
for (; length > 3; length -= 4) {
to_u16_ptr = (u16 *)&align_buffer;
*to_u16_ptr++ = *from_u16_ptr++;
*to_u16_ptr++ = *from_u16_ptr++;
/* This barrier resolves occasional issues seen around
* cases where the data is not properly flushed out
* from the processor store buffers to the destination
* memory locations.
*/
wmb();
/* Output a word */
*to_u32_ptr++ = align_buffer;
}
if (length) {
u8 *from_u8_ptr, *to_u8_ptr;
/* Set up to output the remaining data */
align_buffer = 0;
to_u8_ptr = (u8 *) &align_buffer;
from_u8_ptr = (u8 *) from_u16_ptr;
/* Output the remaining data */
for (; length > 0; length--)
*to_u8_ptr++ = *from_u8_ptr++;
/* This barrier resolves occasional issues seen around
* cases where the data is not properly flushed out
* from the processor store buffers to the destination
* memory locations.
*/
wmb();
*to_u32_ptr = align_buffer;
}
}
/**
* xemaclite_aligned_read - Read from 32-bit aligned to 16-bit aligned buffer
* @src_ptr: Pointer to the 32-bit aligned source address
* @dest_ptr: Pointer to the 16-bit aligned destination address
* @length: Number bytes to read from source to destination
*
* This function reads data from a 32-bit aligned address in the EmacLite device
* to a 16-bit aligned buffer.
*/
static void xemaclite_aligned_read(u32 *src_ptr, u8 *dest_ptr,
unsigned length)
{
u16 *to_u16_ptr, *from_u16_ptr;
u32 *from_u32_ptr;
u32 align_buffer;
from_u32_ptr = src_ptr;
to_u16_ptr = (u16 *) dest_ptr;
for (; length > 3; length -= 4) {
/* Copy each word into the temporary buffer */
align_buffer = *from_u32_ptr++;
from_u16_ptr = (u16 *)&align_buffer;
/* Read data from source */
*to_u16_ptr++ = *from_u16_ptr++;
*to_u16_ptr++ = *from_u16_ptr++;
}
if (length) {
u8 *to_u8_ptr, *from_u8_ptr;
/* Set up to read the remaining data */
to_u8_ptr = (u8 *) to_u16_ptr;
align_buffer = *from_u32_ptr++;
from_u8_ptr = (u8 *) &align_buffer;
/* Read the remaining data */
for (; length > 0; length--)
*to_u8_ptr = *from_u8_ptr;
}
}
/**
* xemaclite_send_data - Send an Ethernet frame
* @drvdata: Pointer to the Emaclite device private data
* @data: Pointer to the data to be sent
* @byte_count: Total frame size, including header
*
* This function checks if the Tx buffer of the Emaclite device is free to send
* data. If so, it fills the Tx buffer with data for transmission. Otherwise, it
* returns an error.
*
* Return: 0 upon success or -1 if the buffer(s) are full.
*
* Note: The maximum Tx packet size can not be more than Ethernet header
* (14 Bytes) + Maximum MTU (1500 bytes). This is excluding FCS.
*/
static int xemaclite_send_data(struct net_local *drvdata, u8 *data,
unsigned int byte_count)
{
u32 reg_data;
void __iomem *addr;
/* Determine the expected Tx buffer address */
addr = drvdata->base_addr + drvdata->next_tx_buf_to_use;
/* If the length is too large, truncate it */
if (byte_count > ETH_FRAME_LEN)
byte_count = ETH_FRAME_LEN;
/* Check if the expected buffer is available */
reg_data = xemaclite_readl(addr + XEL_TSR_OFFSET);
if ((reg_data & (XEL_TSR_XMIT_BUSY_MASK |
XEL_TSR_XMIT_ACTIVE_MASK)) == 0) {
/* Switch to next buffer if configured */
if (drvdata->tx_ping_pong != 0)
drvdata->next_tx_buf_to_use ^= XEL_BUFFER_OFFSET;
} else if (drvdata->tx_ping_pong != 0) {
/* If the expected buffer is full, try the other buffer,
* if it is configured in HW */
addr = (void __iomem __force *)((u32 __force)addr ^
XEL_BUFFER_OFFSET);
reg_data = xemaclite_readl(addr + XEL_TSR_OFFSET);
if ((reg_data & (XEL_TSR_XMIT_BUSY_MASK |
XEL_TSR_XMIT_ACTIVE_MASK)) != 0)
return -1; /* Buffers were full, return failure */
} else
return -1; /* Buffer was full, return failure */
/* Write the frame to the buffer */
xemaclite_aligned_write(data, (u32 __force *) addr, byte_count);
xemaclite_writel((byte_count & XEL_TPLR_LENGTH_MASK),
addr + XEL_TPLR_OFFSET);
/* Update the Tx Status Register to indicate that there is a
* frame to send. Set the XEL_TSR_XMIT_ACTIVE_MASK flag which
* is used by the interrupt handler to check whether a frame
* has been transmitted */
reg_data = xemaclite_readl(addr + XEL_TSR_OFFSET);
reg_data |= (XEL_TSR_XMIT_BUSY_MASK | XEL_TSR_XMIT_ACTIVE_MASK);
xemaclite_writel(reg_data, addr + XEL_TSR_OFFSET);
return 0;
}
/**
* xemaclite_recv_data - Receive a frame
* @drvdata: Pointer to the Emaclite device private data
* @data: Address where the data is to be received
*
* This function is intended to be called from the interrupt context or
* with a wrapper which waits for the receive frame to be available.
*
* Return: Total number of bytes received
*/
static u16 xemaclite_recv_data(struct net_local *drvdata, u8 *data, int maxlen)
{
void __iomem *addr;
u16 length, proto_type;
u32 reg_data;
/* Determine the expected buffer address */
addr = (drvdata->base_addr + drvdata->next_rx_buf_to_use);
/* Verify which buffer has valid data */
reg_data = xemaclite_readl(addr + XEL_RSR_OFFSET);
if ((reg_data & XEL_RSR_RECV_DONE_MASK) == XEL_RSR_RECV_DONE_MASK) {
if (drvdata->rx_ping_pong != 0)
drvdata->next_rx_buf_to_use ^= XEL_BUFFER_OFFSET;
} else {
/* The instance is out of sync, try other buffer if other
* buffer is configured, return 0 otherwise. If the instance is
* out of sync, do not update the 'next_rx_buf_to_use' since it
* will correct on subsequent calls */
if (drvdata->rx_ping_pong != 0)
addr = (void __iomem __force *)((u32 __force)addr ^
XEL_BUFFER_OFFSET);
else
return 0; /* No data was available */
/* Verify that buffer has valid data */
reg_data = xemaclite_readl(addr + XEL_RSR_OFFSET);
if ((reg_data & XEL_RSR_RECV_DONE_MASK) !=
XEL_RSR_RECV_DONE_MASK)
return 0; /* No data was available */
}
/* Get the protocol type of the ethernet frame that arrived */
proto_type = ((ntohl(xemaclite_readl(addr + XEL_HEADER_OFFSET +
XEL_RXBUFF_OFFSET)) >> XEL_HEADER_SHIFT) &
XEL_RPLR_LENGTH_MASK);
/* Check if received ethernet frame is a raw ethernet frame
* or an IP packet or an ARP packet */
if (proto_type > ETH_DATA_LEN) {
if (proto_type == ETH_P_IP) {
length = ((ntohl(xemaclite_readl(addr +
XEL_HEADER_IP_LENGTH_OFFSET +
XEL_RXBUFF_OFFSET)) >>
XEL_HEADER_SHIFT) &
XEL_RPLR_LENGTH_MASK);
length = min_t(u16, length, ETH_DATA_LEN);
length += ETH_HLEN + ETH_FCS_LEN;
} else if (proto_type == ETH_P_ARP)
length = XEL_ARP_PACKET_SIZE + ETH_HLEN + ETH_FCS_LEN;
else
/* Field contains type other than IP or ARP, use max
* frame size and let user parse it */
length = ETH_FRAME_LEN + ETH_FCS_LEN;
} else
/* Use the length in the frame, plus the header and trailer */
length = proto_type + ETH_HLEN + ETH_FCS_LEN;
if (WARN_ON(length > maxlen))
length = maxlen;
/* Read from the EmacLite device */
xemaclite_aligned_read((u32 __force *) (addr + XEL_RXBUFF_OFFSET),
data, length);
/* Acknowledge the frame */
reg_data = xemaclite_readl(addr + XEL_RSR_OFFSET);
reg_data &= ~XEL_RSR_RECV_DONE_MASK;
xemaclite_writel(reg_data, addr + XEL_RSR_OFFSET);
return length;
}
/**
* xemaclite_update_address - Update the MAC address in the device
* @drvdata: Pointer to the Emaclite device private data
* @address_ptr:Pointer to the MAC address (MAC address is a 48-bit value)
*
* Tx must be idle and Rx should be idle for deterministic results.
* It is recommended that this function should be called after the
* initialization and before transmission of any packets from the device.
* The MAC address can be programmed using any of the two transmit
* buffers (if configured).
*/
static void xemaclite_update_address(struct net_local *drvdata,
u8 *address_ptr)
{
void __iomem *addr;
u32 reg_data;
/* Determine the expected Tx buffer address */
addr = drvdata->base_addr + drvdata->next_tx_buf_to_use;
xemaclite_aligned_write(address_ptr, (u32 __force *) addr, ETH_ALEN);
xemaclite_writel(ETH_ALEN, addr + XEL_TPLR_OFFSET);
/* Update the MAC address in the EmacLite */
reg_data = xemaclite_readl(addr + XEL_TSR_OFFSET);
xemaclite_writel(reg_data | XEL_TSR_PROG_MAC_ADDR, addr + XEL_TSR_OFFSET);
/* Wait for EmacLite to finish with the MAC address update */
while ((xemaclite_readl(addr + XEL_TSR_OFFSET) &
XEL_TSR_PROG_MAC_ADDR) != 0)
;
}
/**
* xemaclite_set_mac_address - Set the MAC address for this device
* @dev: Pointer to the network device instance
* @addr: Void pointer to the sockaddr structure
*
* This function copies the HW address from the sockaddr strucutre to the
* net_device structure and updates the address in HW.
*
* Return: Error if the net device is busy or 0 if the addr is set
* successfully
*/
static int xemaclite_set_mac_address(struct net_device *dev, void *address)
{
struct net_local *lp = netdev_priv(dev);
struct sockaddr *addr = address;
if (netif_running(dev))
return -EBUSY;
memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
xemaclite_update_address(lp, dev->dev_addr);
return 0;
}
/**
* xemaclite_tx_timeout - Callback for Tx Timeout
* @dev: Pointer to the network device
*
* This function is called when Tx time out occurs for Emaclite device.
*/
static void xemaclite_tx_timeout(struct net_device *dev)
{
struct net_local *lp = netdev_priv(dev);
unsigned long flags;
dev_err(&lp->ndev->dev, "Exceeded transmit timeout of %lu ms\n",
TX_TIMEOUT * 1000UL / HZ);
dev->stats.tx_errors++;
/* Reset the device */
spin_lock_irqsave(&lp->reset_lock, flags);
/* Shouldn't really be necessary, but shouldn't hurt */
netif_stop_queue(dev);
xemaclite_disable_interrupts(lp);
xemaclite_enable_interrupts(lp);
if (lp->deferred_skb) {
dev_kfree_skb(lp->deferred_skb);
lp->deferred_skb = NULL;
dev->stats.tx_errors++;
}
/* To exclude tx timeout */
netif_trans_update(dev); /* prevent tx timeout */
/* We're all ready to go. Start the queue */
netif_wake_queue(dev);
spin_unlock_irqrestore(&lp->reset_lock, flags);
}
/**********************/
/* Interrupt Handlers */
/**********************/
/**
* xemaclite_tx_handler - Interrupt handler for frames sent
* @dev: Pointer to the network device
*
* This function updates the number of packets transmitted and handles the
* deferred skb, if there is one.
*/
static void xemaclite_tx_handler(struct net_device *dev)
{
struct net_local *lp = netdev_priv(dev);
dev->stats.tx_packets++;
if (lp->deferred_skb) {
if (xemaclite_send_data(lp,
(u8 *) lp->deferred_skb->data,
lp->deferred_skb->len) != 0)
return;
else {
dev->stats.tx_bytes += lp->deferred_skb->len;
dev_kfree_skb_irq(lp->deferred_skb);
lp->deferred_skb = NULL;
netif_trans_update(dev); /* prevent tx timeout */
netif_wake_queue(dev);
}
}
}
/**
* xemaclite_rx_handler- Interrupt handler for frames received
* @dev: Pointer to the network device
*
* This function allocates memory for a socket buffer, fills it with data
* received and hands it over to the TCP/IP stack.
*/
static void xemaclite_rx_handler(struct net_device *dev)
{
struct net_local *lp = netdev_priv(dev);
struct sk_buff *skb;
unsigned int align;
u32 len;
len = ETH_FRAME_LEN + ETH_FCS_LEN;
skb = netdev_alloc_skb(dev, len + ALIGNMENT);
if (!skb) {
/* Couldn't get memory. */
dev->stats.rx_dropped++;
dev_err(&lp->ndev->dev, "Could not allocate receive buffer\n");
return;
}
/*
* A new skb should have the data halfword aligned, but this code is
* here just in case that isn't true. Calculate how many
* bytes we should reserve to get the data to start on a word
* boundary */
align = BUFFER_ALIGN(skb->data);
if (align)
skb_reserve(skb, align);
skb_reserve(skb, 2);
len = xemaclite_recv_data(lp, (u8 *) skb->data, len);
if (!len) {
dev->stats.rx_errors++;
dev_kfree_skb_irq(skb);
return;
}
skb_put(skb, len); /* Tell the skb how much data we got */
skb->protocol = eth_type_trans(skb, dev);
skb_checksum_none_assert(skb);
dev->stats.rx_packets++;
dev->stats.rx_bytes += len;
if (!skb_defer_rx_timestamp(skb))
netif_rx(skb); /* Send the packet upstream */
}
/**
* xemaclite_interrupt - Interrupt handler for this driver
* @irq: Irq of the Emaclite device
* @dev_id: Void pointer to the network device instance used as callback
* reference
*
* This function handles the Tx and Rx interrupts of the EmacLite device.
*/
static irqreturn_t xemaclite_interrupt(int irq, void *dev_id)
{
bool tx_complete = false;
struct net_device *dev = dev_id;
struct net_local *lp = netdev_priv(dev);
void __iomem *base_addr = lp->base_addr;
u32 tx_status;
/* Check if there is Rx Data available */
if ((xemaclite_readl(base_addr + XEL_RSR_OFFSET) &
XEL_RSR_RECV_DONE_MASK) ||
(xemaclite_readl(base_addr + XEL_BUFFER_OFFSET + XEL_RSR_OFFSET)
& XEL_RSR_RECV_DONE_MASK))
xemaclite_rx_handler(dev);
/* Check if the Transmission for the first buffer is completed */
tx_status = xemaclite_readl(base_addr + XEL_TSR_OFFSET);
if (((tx_status & XEL_TSR_XMIT_BUSY_MASK) == 0) &&
(tx_status & XEL_TSR_XMIT_ACTIVE_MASK) != 0) {
tx_status &= ~XEL_TSR_XMIT_ACTIVE_MASK;
xemaclite_writel(tx_status, base_addr + XEL_TSR_OFFSET);
tx_complete = true;
}
/* Check if the Transmission for the second buffer is completed */
tx_status = xemaclite_readl(base_addr + XEL_BUFFER_OFFSET + XEL_TSR_OFFSET);
if (((tx_status & XEL_TSR_XMIT_BUSY_MASK) == 0) &&
(tx_status & XEL_TSR_XMIT_ACTIVE_MASK) != 0) {
tx_status &= ~XEL_TSR_XMIT_ACTIVE_MASK;
xemaclite_writel(tx_status, base_addr + XEL_BUFFER_OFFSET +
XEL_TSR_OFFSET);
tx_complete = true;
}
/* If there was a Tx interrupt, call the Tx Handler */
if (tx_complete != 0)
xemaclite_tx_handler(dev);
return IRQ_HANDLED;
}
/**********************/
/* MDIO Bus functions */
/**********************/
/**
* xemaclite_mdio_wait - Wait for the MDIO to be ready to use
* @lp: Pointer to the Emaclite device private data
*
* This function waits till the device is ready to accept a new MDIO
* request.
*
* Return: 0 for success or ETIMEDOUT for a timeout
*/
static int xemaclite_mdio_wait(struct net_local *lp)
{
unsigned long end = jiffies + 2;
/* wait for the MDIO interface to not be busy or timeout
after some time.
*/
while (xemaclite_readl(lp->base_addr + XEL_MDIOCTRL_OFFSET) &
XEL_MDIOCTRL_MDIOSTS_MASK) {
if (time_before_eq(end, jiffies)) {
WARN_ON(1);
return -ETIMEDOUT;
}
msleep(1);
}
return 0;
}
/**
* xemaclite_mdio_read - Read from a given MII management register
* @bus: the mii_bus struct
* @phy_id: the phy address
* @reg: register number to read from
*
* This function waits till the device is ready to accept a new MDIO
* request and then writes the phy address to the MDIO Address register
* and reads data from MDIO Read Data register, when its available.
*
* Return: Value read from the MII management register
*/
static int xemaclite_mdio_read(struct mii_bus *bus, int phy_id, int reg)
{
struct net_local *lp = bus->priv;
u32 ctrl_reg;
u32 rc;
if (xemaclite_mdio_wait(lp))
return -ETIMEDOUT;
/* Write the PHY address, register number and set the OP bit in the
* MDIO Address register. Set the Status bit in the MDIO Control
* register to start a MDIO read transaction.
*/
ctrl_reg = xemaclite_readl(lp->base_addr + XEL_MDIOCTRL_OFFSET);
xemaclite_writel(XEL_MDIOADDR_OP_MASK |
((phy_id << XEL_MDIOADDR_PHYADR_SHIFT) | reg),
lp->base_addr + XEL_MDIOADDR_OFFSET);
xemaclite_writel(ctrl_reg | XEL_MDIOCTRL_MDIOSTS_MASK,
lp->base_addr + XEL_MDIOCTRL_OFFSET);
if (xemaclite_mdio_wait(lp))
return -ETIMEDOUT;
rc = xemaclite_readl(lp->base_addr + XEL_MDIORD_OFFSET);
dev_dbg(&lp->ndev->dev,
"xemaclite_mdio_read(phy_id=%i, reg=%x) == %x\n",
phy_id, reg, rc);
return rc;
}
/**
* xemaclite_mdio_write - Write to a given MII management register
* @bus: the mii_bus struct
* @phy_id: the phy address
* @reg: register number to write to
* @val: value to write to the register number specified by reg
*
* This function waits till the device is ready to accept a new MDIO
* request and then writes the val to the MDIO Write Data register.
*/
static int xemaclite_mdio_write(struct mii_bus *bus, int phy_id, int reg,
u16 val)
{
struct net_local *lp = bus->priv;
u32 ctrl_reg;
dev_dbg(&lp->ndev->dev,
"xemaclite_mdio_write(phy_id=%i, reg=%x, val=%x)\n",
phy_id, reg, val);
if (xemaclite_mdio_wait(lp))
return -ETIMEDOUT;
/* Write the PHY address, register number and clear the OP bit in the
* MDIO Address register and then write the value into the MDIO Write
* Data register. Finally, set the Status bit in the MDIO Control
* register to start a MDIO write transaction.
*/
ctrl_reg = xemaclite_readl(lp->base_addr + XEL_MDIOCTRL_OFFSET);
xemaclite_writel(~XEL_MDIOADDR_OP_MASK &
((phy_id << XEL_MDIOADDR_PHYADR_SHIFT) | reg),
lp->base_addr + XEL_MDIOADDR_OFFSET);
xemaclite_writel(val, lp->base_addr + XEL_MDIOWR_OFFSET);
xemaclite_writel(ctrl_reg | XEL_MDIOCTRL_MDIOSTS_MASK,
lp->base_addr + XEL_MDIOCTRL_OFFSET);
return 0;
}
/**
* xemaclite_mdio_setup - Register mii_bus for the Emaclite device
* @lp: Pointer to the Emaclite device private data
* @ofdev: Pointer to OF device structure
*
* This function enables MDIO bus in the Emaclite device and registers a
* mii_bus.
*
* Return: 0 upon success or a negative error upon failure
*/
static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
{
struct mii_bus *bus;
int rc;
struct resource res;
struct device_node *np = of_get_parent(lp->phy_node);
struct device_node *npp;
/* Don't register the MDIO bus if the phy_node or its parent node
* can't be found.
*/
if (!np) {
dev_err(dev, "Failed to register mdio bus.\n");
return -ENODEV;
}
npp = of_get_parent(np);
of_address_to_resource(npp, 0, &res);
if (lp->ndev->mem_start != res.start) {
struct phy_device *phydev;
phydev = of_phy_find_device(lp->phy_node);
if (!phydev)
dev_info(dev,
"MDIO of the phy is not registered yet\n");
else
put_device(&phydev->mdio.dev);
return 0;
}
/* Enable the MDIO bus by asserting the enable bit in MDIO Control
* register.
*/
xemaclite_writel(XEL_MDIOCTRL_MDIOEN_MASK,
lp->base_addr + XEL_MDIOCTRL_OFFSET);
bus = mdiobus_alloc();
if (!bus) {
dev_err(dev, "Failed to allocate mdiobus\n");
return -ENOMEM;
}
snprintf(bus->id, MII_BUS_ID_SIZE, "%.8llx",
(unsigned long long)res.start);
bus->priv = lp;
bus->name = "Xilinx Emaclite MDIO";
bus->read = xemaclite_mdio_read;
bus->write = xemaclite_mdio_write;
bus->parent = dev;
lp->mii_bus = bus;
rc = of_mdiobus_register(bus, np);
if (rc) {
dev_err(dev, "Failed to register mdio bus.\n");
goto err_register;
}
return 0;
err_register:
mdiobus_free(bus);
return rc;
}
/**
* xemaclite_adjust_link - Link state callback for the Emaclite device
* @ndev: pointer to net_device struct
*
* There's nothing in the Emaclite device to be configured when the link
* state changes. We just print the status.
*/
static void xemaclite_adjust_link(struct net_device *ndev)
{
struct net_local *lp = netdev_priv(ndev);
struct phy_device *phy = lp->phy_dev;
int link_state;
/* hash together the state values to decide if something has changed */
link_state = phy->speed | (phy->duplex << 1) | phy->link;
if (lp->last_link != link_state) {
lp->last_link = link_state;
phy_print_status(phy);
}
}
/**
* xemaclite_open - Open the network device
* @dev: Pointer to the network device
*
* This function sets the MAC address, requests an IRQ and enables interrupts
* for the Emaclite device and starts the Tx queue.
* It also connects to the phy device, if MDIO is included in Emaclite device.
*/
static int xemaclite_open(struct net_device *dev)
{
struct net_local *lp = netdev_priv(dev);
int retval;
/* Just to be safe, stop the device first */
xemaclite_disable_interrupts(lp);
if (lp->phy_node) {
u32 bmcr;
lp->phy_dev = of_phy_connect(lp->ndev, lp->phy_node,
xemaclite_adjust_link, 0,
PHY_INTERFACE_MODE_MII);
if (!lp->phy_dev) {
dev_err(&lp->ndev->dev, "of_phy_connect() failed\n");
return -ENODEV;
}
/* EmacLite doesn't support giga-bit speeds */
lp->phy_dev->supported &= (PHY_BASIC_FEATURES);
lp->phy_dev->advertising = lp->phy_dev->supported;
/* Don't advertise 1000BASE-T Full/Half duplex speeds */
phy_write(lp->phy_dev, MII_CTRL1000, 0);
/* Advertise only 10 and 100mbps full/half duplex speeds */
phy_write(lp->phy_dev, MII_ADVERTISE, ADVERTISE_ALL |
ADVERTISE_CSMA);
/* Restart auto negotiation */
bmcr = phy_read(lp->phy_dev, MII_BMCR);
bmcr |= (BMCR_ANENABLE | BMCR_ANRESTART);
phy_write(lp->phy_dev, MII_BMCR, bmcr);
phy_start(lp->phy_dev);
}
/* Set the MAC address each time opened */
xemaclite_update_address(lp, dev->dev_addr);
/* Grab the IRQ */
retval = request_irq(dev->irq, xemaclite_interrupt, 0, dev->name, dev);
if (retval) {
dev_err(&lp->ndev->dev, "Could not allocate interrupt %d\n",
dev->irq);
if (lp->phy_dev)
phy_disconnect(lp->phy_dev);
lp->phy_dev = NULL;
return retval;
}
/* Enable Interrupts */
xemaclite_enable_interrupts(lp);
/* We're ready to go */
netif_start_queue(dev);
return 0;
}
/**
* xemaclite_close - Close the network device
* @dev: Pointer to the network device
*
* This function stops the Tx queue, disables interrupts and frees the IRQ for
* the Emaclite device.
* It also disconnects the phy device associated with the Emaclite device.
*/
static int xemaclite_close(struct net_device *dev)
{
struct net_local *lp = netdev_priv(dev);
netif_stop_queue(dev);
xemaclite_disable_interrupts(lp);
free_irq(dev->irq, dev);
if (lp->phy_dev)
phy_disconnect(lp->phy_dev);
lp->phy_dev = NULL;
return 0;
}
/**
* xemaclite_send - Transmit a frame
* @orig_skb: Pointer to the socket buffer to be transmitted
* @dev: Pointer to the network device
*
* This function checks if the Tx buffer of the Emaclite device is free to send
* data. If so, it fills the Tx buffer with data from socket buffer data,
* updates the stats and frees the socket buffer. The Tx completion is signaled
* by an interrupt. If the Tx buffer isn't free, then the socket buffer is
* deferred and the Tx queue is stopped so that the deferred socket buffer can
* be transmitted when the Emaclite device is free to transmit data.
*
* Return: NETDEV_TX_OK, always.
*/
static netdev_tx_t
xemaclite_send(struct sk_buff *orig_skb, struct net_device *dev)
{
struct net_local *lp = netdev_priv(dev);
struct sk_buff *new_skb;
unsigned int len;
unsigned long flags;
len = orig_skb->len;
new_skb = orig_skb;
spin_lock_irqsave(&lp->reset_lock, flags);
if (xemaclite_send_data(lp, (u8 *) new_skb->data, len) != 0) {
/* If the Emaclite Tx buffer is busy, stop the Tx queue and
* defer the skb for transmission during the ISR, after the
* current transmission is complete */
netif_stop_queue(dev);
lp->deferred_skb = new_skb;
/* Take the time stamp now, since we can't do this in an ISR. */
skb_tx_timestamp(new_skb);
spin_unlock_irqrestore(&lp->reset_lock, flags);
return NETDEV_TX_OK;
}
spin_unlock_irqrestore(&lp->reset_lock, flags);
skb_tx_timestamp(new_skb);
dev->stats.tx_bytes += len;
dev_consume_skb_any(new_skb);
return NETDEV_TX_OK;
}
/**
* xemaclite_remove_ndev - Free the network device
* @ndev: Pointer to the network device to be freed
*
* This function un maps the IO region of the Emaclite device and frees the net
* device.
*/
static void xemaclite_remove_ndev(struct net_device *ndev)
{
if (ndev) {
free_netdev(ndev);
}
}
/**
* get_bool - Get a parameter from the OF device
* @ofdev: Pointer to OF device structure
* @s: Property to be retrieved
*
* This function looks for a property in the device node and returns the value
* of the property if its found or 0 if the property is not found.
*
* Return: Value of the parameter if the parameter is found, or 0 otherwise
*/
static bool get_bool(struct platform_device *ofdev, const char *s)
{
u32 *p = (u32 *)of_get_property(ofdev->dev.of_node, s, NULL);
if (p) {
return (bool)*p;
} else {
dev_warn(&ofdev->dev, "Parameter %s not found,"
"defaulting to false\n", s);
return false;
}
}
static struct net_device_ops xemaclite_netdev_ops;
/**
* xemaclite_of_probe - Probe method for the Emaclite device.
* @ofdev: Pointer to OF device structure
* @match: Pointer to the structure used for matching a device
*
* This function probes for the Emaclite device in the device tree.
* It initializes the driver data structure and the hardware, sets the MAC
* address and registers the network device.
* It also registers a mii_bus for the Emaclite device, if MDIO is included
* in the device.
*
* Return: 0, if the driver is bound to the Emaclite device, or
* a negative error if there is failure.
*/
static int xemaclite_of_probe(struct platform_device *ofdev)
{
struct resource *res;
struct net_device *ndev = NULL;
struct net_local *lp = NULL;
struct device *dev = &ofdev->dev;
const void *mac_address;
int rc = 0;
dev_info(dev, "Device Tree Probing\n");
/* Create an ethernet device instance */
ndev = alloc_etherdev(sizeof(struct net_local));
if (!ndev)
return -ENOMEM;
dev_set_drvdata(dev, ndev);
SET_NETDEV_DEV(ndev, &ofdev->dev);
lp = netdev_priv(ndev);
lp->ndev = ndev;
/* Get IRQ for the device */
res = platform_get_resource(ofdev, IORESOURCE_IRQ, 0);
if (!res) {
dev_err(dev, "no IRQ found\n");
rc = -ENXIO;
goto error;
}
ndev->irq = res->start;
res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
lp->base_addr = devm_ioremap_resource(&ofdev->dev, res);
if (IS_ERR(lp->base_addr)) {
rc = PTR_ERR(lp->base_addr);
goto error;
}
ndev->mem_start = res->start;
ndev->mem_end = res->end;
spin_lock_init(&lp->reset_lock);
lp->next_tx_buf_to_use = 0x0;
lp->next_rx_buf_to_use = 0x0;
lp->tx_ping_pong = get_bool(ofdev, "xlnx,tx-ping-pong");
lp->rx_ping_pong = get_bool(ofdev, "xlnx,rx-ping-pong");
mac_address = of_get_mac_address(ofdev->dev.of_node);
if (mac_address) {
/* Set the MAC address. */
memcpy(ndev->dev_addr, mac_address, ETH_ALEN);
} else {
dev_warn(dev, "No MAC address found, using random\n");
eth_hw_addr_random(ndev);
}
/* Clear the Tx CSR's in case this is a restart */
xemaclite_writel(0, lp->base_addr + XEL_TSR_OFFSET);
xemaclite_writel(0, lp->base_addr + XEL_BUFFER_OFFSET + XEL_TSR_OFFSET);
/* Set the MAC address in the EmacLite device */
xemaclite_update_address(lp, ndev->dev_addr);
lp->phy_node = of_parse_phandle(ofdev->dev.of_node, "phy-handle", 0);
rc = xemaclite_mdio_setup(lp, &ofdev->dev);
if (rc)
dev_warn(&ofdev->dev, "error registering MDIO bus\n");
dev_info(dev, "MAC address is now %pM\n", ndev->dev_addr);
ndev->netdev_ops = &xemaclite_netdev_ops;
ndev->flags &= ~IFF_MULTICAST;
ndev->watchdog_timeo = TX_TIMEOUT;
/* Finally, register the device */
rc = register_netdev(ndev);
if (rc) {
dev_err(dev,
"Cannot register network device, aborting\n");
goto error;
}
dev_info(dev,
"Xilinx EmacLite at 0x%08X mapped to 0x%08X, irq=%d\n",
(unsigned int __force)ndev->mem_start,
(unsigned int __force)lp->base_addr, ndev->irq);
return 0;
error:
xemaclite_remove_ndev(ndev);
return rc;
}
/**
* xemaclite_of_remove - Unbind the driver from the Emaclite device.
* @of_dev: Pointer to OF device structure
*
* This function is called if a device is physically removed from the system or
* if the driver module is being unloaded. It frees any resources allocated to
* the device.
*
* Return: 0, always.
*/
static int xemaclite_of_remove(struct platform_device *of_dev)
{
struct net_device *ndev = platform_get_drvdata(of_dev);
struct net_local *lp = netdev_priv(ndev);
/* Un-register the mii_bus, if configured */
if (lp->has_mdio) {
mdiobus_unregister(lp->mii_bus);
mdiobus_free(lp->mii_bus);
lp->mii_bus = NULL;
}
unregister_netdev(ndev);
of_node_put(lp->phy_node);
lp->phy_node = NULL;
xemaclite_remove_ndev(ndev);
return 0;
}
#ifdef CONFIG_NET_POLL_CONTROLLER
static void
xemaclite_poll_controller(struct net_device *ndev)
{
disable_irq(ndev->irq);
xemaclite_interrupt(ndev->irq, ndev);
enable_irq(ndev->irq);
}
#endif
static struct net_device_ops xemaclite_netdev_ops = {
.ndo_open = xemaclite_open,
.ndo_stop = xemaclite_close,
.ndo_start_xmit = xemaclite_send,
.ndo_set_mac_address = xemaclite_set_mac_address,
.ndo_tx_timeout = xemaclite_tx_timeout,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = xemaclite_poll_controller,
#endif
};
/* Match table for OF platform binding */
static const struct of_device_id xemaclite_of_match[] = {
{ .compatible = "xlnx,opb-ethernetlite-1.01.a", },
{ .compatible = "xlnx,opb-ethernetlite-1.01.b", },
{ .compatible = "xlnx,xps-ethernetlite-1.00.a", },
{ .compatible = "xlnx,xps-ethernetlite-2.00.a", },
{ .compatible = "xlnx,xps-ethernetlite-2.01.a", },
{ .compatible = "xlnx,xps-ethernetlite-3.00.a", },
{ /* end of list */ },
};
MODULE_DEVICE_TABLE(of, xemaclite_of_match);
static struct platform_driver xemaclite_of_driver = {
.driver = {
.name = DRIVER_NAME,
.of_match_table = xemaclite_of_match,
},
.probe = xemaclite_of_probe,
.remove = xemaclite_of_remove,
};
module_platform_driver(xemaclite_of_driver);
MODULE_AUTHOR("Xilinx, Inc.");
MODULE_DESCRIPTION("Xilinx Ethernet MAC Lite driver");
MODULE_LICENSE("GPL");