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Merge branch 'can/at91_can-for-net-2.6' of git://git.pengutronix.de/git/mkl/linux-2.6

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This commit is contained in:
David S. Miller 2011-01-24 15:16:11 -08:00
commit 5955e75247
2 changed files with 137 additions and 26 deletions
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138
drivers/net/can/at91_can.c
View file

@ -2,7 +2,7 @@
* at91_can.c - CAN network driver for AT91 SoC CAN controller
*
* (C) 2007 by Hans J. Koch <hjk@hansjkoch.de>
* (C) 2008, 2009, 2010 by Marc Kleine-Budde <kernel@pengutronix.de>
* (C) 2008, 2009, 2010, 2011 by Marc Kleine-Budde <kernel@pengutronix.de>
*
* This software may be distributed under the terms of the GNU General
* Public License ("GPL") version 2 as distributed in the 'COPYING'
@ -30,6 +30,7 @@
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/platform_device.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/string.h>
@ -40,22 +41,23 @@
#include <mach/board.h>
#define AT91_NAPI_WEIGHT 12
#define AT91_NAPI_WEIGHT 11
/*
* RX/TX Mailbox split
* don't dare to touch
*/
#define AT91_MB_RX_NUM 12
#define AT91_MB_RX_NUM 11
#define AT91_MB_TX_SHIFT 2
#define AT91_MB_RX_FIRST 0
#define AT91_MB_RX_FIRST 1
#define AT91_MB_RX_LAST (AT91_MB_RX_FIRST + AT91_MB_RX_NUM - 1)
#define AT91_MB_RX_MASK(i) ((1 << (i)) - 1)
#define AT91_MB_RX_SPLIT 8
#define AT91_MB_RX_LOW_LAST (AT91_MB_RX_SPLIT - 1)
#define AT91_MB_RX_LOW_MASK (AT91_MB_RX_MASK(AT91_MB_RX_SPLIT))
#define AT91_MB_RX_LOW_MASK (AT91_MB_RX_MASK(AT91_MB_RX_SPLIT) & \
~AT91_MB_RX_MASK(AT91_MB_RX_FIRST))
#define AT91_MB_TX_NUM (1 << AT91_MB_TX_SHIFT)
#define AT91_MB_TX_FIRST (AT91_MB_RX_LAST + 1)
@ -168,6 +170,8 @@ struct at91_priv {
struct clk *clk;
struct at91_can_data *pdata;
canid_t mb0_id;
};
static struct can_bittiming_const at91_bittiming_const = {
@ -220,6 +224,18 @@ static inline void set_mb_mode(const struct at91_priv *priv, unsigned int mb,
set_mb_mode_prio(priv, mb, mode, 0);
}
static inline u32 at91_can_id_to_reg_mid(canid_t can_id)
{
u32 reg_mid;
if (can_id & CAN_EFF_FLAG)
reg_mid = (can_id & CAN_EFF_MASK) | AT91_MID_MIDE;
else
reg_mid = (can_id & CAN_SFF_MASK) << 18;
return reg_mid;
}
/*
* Swtich transceiver on or off
*/
@ -233,12 +249,22 @@ static void at91_setup_mailboxes(struct net_device *dev)
{
struct at91_priv *priv = netdev_priv(dev);
unsigned int i;
u32 reg_mid;
/*
* The first 12 mailboxes are used as a reception FIFO. The
* last mailbox is configured with overwrite option. The
* overwrite flag indicates a FIFO overflow.
* Due to a chip bug (errata 50.2.6.3 & 50.3.5.3) the first
* mailbox is disabled. The next 11 mailboxes are used as a
* reception FIFO. The last mailbox is configured with
* overwrite option. The overwrite flag indicates a FIFO
* overflow.
*/
reg_mid = at91_can_id_to_reg_mid(priv->mb0_id);
for (i = 0; i < AT91_MB_RX_FIRST; i++) {
set_mb_mode(priv, i, AT91_MB_MODE_DISABLED);
at91_write(priv, AT91_MID(i), reg_mid);
at91_write(priv, AT91_MCR(i), 0x0); /* clear dlc */
}
for (i = AT91_MB_RX_FIRST; i < AT91_MB_RX_LAST; i++)
set_mb_mode(priv, i, AT91_MB_MODE_RX);
set_mb_mode(priv, AT91_MB_RX_LAST, AT91_MB_MODE_RX_OVRWR);
@ -254,7 +280,8 @@ static void at91_setup_mailboxes(struct net_device *dev)
set_mb_mode_prio(priv, i, AT91_MB_MODE_TX, 0);
/* Reset tx and rx helper pointers */
priv->tx_next = priv->tx_echo = priv->rx_next = 0;
priv->tx_next = priv->tx_echo = 0;
priv->rx_next = AT91_MB_RX_FIRST;
}
static int at91_set_bittiming(struct net_device *dev)
@ -372,12 +399,7 @@ static netdev_tx_t at91_start_xmit(struct sk_buff *skb, struct net_device *dev)
netdev_err(dev, "BUG! TX buffer full when queue awake!\n");
return NETDEV_TX_BUSY;
}
if (cf->can_id & CAN_EFF_FLAG)
reg_mid = (cf->can_id & CAN_EFF_MASK) | AT91_MID_MIDE;
else
reg_mid = (cf->can_id & CAN_SFF_MASK) << 18;
reg_mid = at91_can_id_to_reg_mid(cf->can_id);
reg_mcr = ((cf->can_id & CAN_RTR_FLAG) ? AT91_MCR_MRTR : 0) |
(cf->can_dlc << 16) | AT91_MCR_MTCR;
@ -539,27 +561,31 @@ static void at91_read_msg(struct net_device *dev, unsigned int mb)
*
* Theory of Operation:
*
* 12 of the 16 mailboxes on the chip are reserved for RX. we split
* them into 2 groups. The lower group holds 8 and upper 4 mailboxes.
* 11 of the 16 mailboxes on the chip are reserved for RX. we split
* them into 2 groups. The lower group holds 7 and upper 4 mailboxes.
*
* Like it or not, but the chip always saves a received CAN message
* into the first free mailbox it finds (starting with the
* lowest). This makes it very difficult to read the messages in the
* right order from the chip. This is how we work around that problem:
*
* The first message goes into mb nr. 0 and issues an interrupt. All
* The first message goes into mb nr. 1 and issues an interrupt. All
* rx ints are disabled in the interrupt handler and a napi poll is
* scheduled. We read the mailbox, but do _not_ reenable the mb (to
* receive another message).
*
* lower mbxs upper
* ______^______ __^__
* / \ / \
* ____^______ __^__
* / \ / \
* +-+-+-+-+-+-+-+-++-+-+-+-+
* |x|x|x|x|x|x|x|x|| | | | |
* | |x|x|x|x|x|x|x|| | | | |
* +-+-+-+-+-+-+-+-++-+-+-+-+
* 0 0 0 0 0 0 0 0 0 0 1 1 \ mail
* 0 1 2 3 4 5 6 7 8 9 0 1 / box
* ^
* |
* \
* unused, due to chip bug
*
* The variable priv->rx_next points to the next mailbox to read a
* message from. As long we're in the lower mailboxes we just read the
@ -590,10 +616,10 @@ static int at91_poll_rx(struct net_device *dev, int quota)
"order of incoming frames cannot be guaranteed\n");
again:
for (mb = find_next_bit(addr, AT91_MB_RX_NUM, priv->rx_next);
mb < AT91_MB_RX_NUM && quota > 0;
for (mb = find_next_bit(addr, AT91_MB_RX_LAST + 1, priv->rx_next);
mb < AT91_MB_RX_LAST + 1 && quota > 0;
reg_sr = at91_read(priv, AT91_SR),
mb = find_next_bit(addr, AT91_MB_RX_NUM, ++priv->rx_next)) {
mb = find_next_bit(addr, AT91_MB_RX_LAST + 1, ++priv->rx_next)) {
at91_read_msg(dev, mb);
/* reactivate mailboxes */
@ -610,8 +636,8 @@ static int at91_poll_rx(struct net_device *dev, int quota)
/* upper group completed, look again in lower */
if (priv->rx_next > AT91_MB_RX_LOW_LAST &&
quota > 0 && mb >= AT91_MB_RX_NUM) {
priv->rx_next = 0;
quota > 0 && mb > AT91_MB_RX_LAST) {
priv->rx_next = AT91_MB_RX_FIRST;
goto again;
}
@ -1037,6 +1063,64 @@ static const struct net_device_ops at91_netdev_ops = {
.ndo_start_xmit = at91_start_xmit,
};
static ssize_t at91_sysfs_show_mb0_id(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct at91_priv *priv = netdev_priv(to_net_dev(dev));
if (priv->mb0_id & CAN_EFF_FLAG)
return snprintf(buf, PAGE_SIZE, "0x%08x\n", priv->mb0_id);
else
return snprintf(buf, PAGE_SIZE, "0x%03x\n", priv->mb0_id);
}
static ssize_t at91_sysfs_set_mb0_id(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct net_device *ndev = to_net_dev(dev);
struct at91_priv *priv = netdev_priv(ndev);
unsigned long can_id;
ssize_t ret;
int err;
rtnl_lock();
if (ndev->flags & IFF_UP) {
ret = -EBUSY;
goto out;
}
err = strict_strtoul(buf, 0, &can_id);
if (err) {
ret = err;
goto out;
}
if (can_id & CAN_EFF_FLAG)
can_id &= CAN_EFF_MASK | CAN_EFF_FLAG;
else
can_id &= CAN_SFF_MASK;
priv->mb0_id = can_id;
ret = count;
out:
rtnl_unlock();
return ret;
}
static DEVICE_ATTR(mb0_id, S_IWUGO | S_IRUGO,
at91_sysfs_show_mb0_id, at91_sysfs_set_mb0_id);
static struct attribute *at91_sysfs_attrs[] = {
&dev_attr_mb0_id.attr,
NULL,
};
static struct attribute_group at91_sysfs_attr_group = {
.attrs = at91_sysfs_attrs,
};
static int __devinit at91_can_probe(struct platform_device *pdev)
{
struct net_device *dev;
@ -1082,6 +1166,7 @@ static int __devinit at91_can_probe(struct platform_device *pdev)
dev->netdev_ops = &at91_netdev_ops;
dev->irq = irq;
dev->flags |= IFF_ECHO;
dev->sysfs_groups[0] = &at91_sysfs_attr_group;
priv = netdev_priv(dev);
priv->can.clock.freq = clk_get_rate(clk);
@ -1093,6 +1178,7 @@ static int __devinit at91_can_probe(struct platform_device *pdev)
priv->dev = dev;
priv->clk = clk;
priv->pdata = pdev->dev.platform_data;
priv->mb0_id = 0x7ff;
netif_napi_add(dev, &priv->napi, at91_poll, AT91_NAPI_WEIGHT);