* 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'
#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>
#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)
struct clk *clk;
struct at91_can_data *pdata;
+
+ canid_t mb0_id;
};
static struct can_bittiming_const at91_bittiming_const = {
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
*/
{
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);
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)
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;
*
* 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
"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 */
/* 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;
}
.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_IWUSR | 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;
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);
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);
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