Merge branch 'can/at91_can-for-net-2.6' of git://git.pengutronix.de/git/mkl/linux-2.6
This commit is contained in:
25
Documentation/ABI/testing/sysfs-platform-at91
Normal file
25
Documentation/ABI/testing/sysfs-platform-at91
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@@ -0,0 +1,25 @@
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What: /sys/devices/platform/at91_can/net/<iface>/mb0_id
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Date: January 2011
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KernelVersion: 2.6.38
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Contact: Marc Kleine-Budde <kernel@pengutronix.de>
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Description:
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Value representing the can_id of mailbox 0.
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Default: 0x7ff (standard frame)
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Due to a chip bug (errata 50.2.6.3 & 50.3.5.3 in
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"AT91SAM9263 Preliminary 6249H-ATARM-27-Jul-09") the
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contents of mailbox 0 may be send under certain
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conditions (even if disabled or in rx mode).
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The workaround in the errata suggests not to use the
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mailbox and load it with an unused identifier.
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In order to use an extended can_id add the
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CAN_EFF_FLAG (0x80000000U) to the can_id. Example:
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- standard id 0x7ff:
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echo 0x7ff > /sys/class/net/can0/mb0_id
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- extended id 0x1fffffff:
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echo 0x9fffffff > /sys/class/net/can0/mb0_id
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@@ -2,7 +2,7 @@
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* at91_can.c - CAN network driver for AT91 SoC CAN controller
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* at91_can.c - CAN network driver for AT91 SoC CAN controller
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*
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*
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* (C) 2007 by Hans J. Koch <hjk@hansjkoch.de>
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* (C) 2007 by Hans J. Koch <hjk@hansjkoch.de>
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* (C) 2008, 2009, 2010 by Marc Kleine-Budde <kernel@pengutronix.de>
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* (C) 2008, 2009, 2010, 2011 by Marc Kleine-Budde <kernel@pengutronix.de>
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*
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*
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* This software may be distributed under the terms of the GNU General
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* This software may be distributed under the terms of the GNU General
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* Public License ("GPL") version 2 as distributed in the 'COPYING'
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* Public License ("GPL") version 2 as distributed in the 'COPYING'
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@@ -30,6 +30,7 @@
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#include <linux/module.h>
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#include <linux/module.h>
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#include <linux/netdevice.h>
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#include <linux/netdevice.h>
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#include <linux/platform_device.h>
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#include <linux/platform_device.h>
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#include <linux/rtnetlink.h>
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#include <linux/skbuff.h>
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#include <linux/skbuff.h>
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#include <linux/spinlock.h>
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#include <linux/spinlock.h>
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#include <linux/string.h>
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#include <linux/string.h>
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@@ -40,22 +41,23 @@
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#include <mach/board.h>
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#include <mach/board.h>
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#define AT91_NAPI_WEIGHT 12
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#define AT91_NAPI_WEIGHT 11
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/*
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/*
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* RX/TX Mailbox split
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* RX/TX Mailbox split
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* don't dare to touch
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* don't dare to touch
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*/
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*/
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#define AT91_MB_RX_NUM 12
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#define AT91_MB_RX_NUM 11
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#define AT91_MB_TX_SHIFT 2
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#define AT91_MB_TX_SHIFT 2
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#define AT91_MB_RX_FIRST 0
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#define AT91_MB_RX_FIRST 1
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#define AT91_MB_RX_LAST (AT91_MB_RX_FIRST + AT91_MB_RX_NUM - 1)
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#define AT91_MB_RX_LAST (AT91_MB_RX_FIRST + AT91_MB_RX_NUM - 1)
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#define AT91_MB_RX_MASK(i) ((1 << (i)) - 1)
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#define AT91_MB_RX_MASK(i) ((1 << (i)) - 1)
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#define AT91_MB_RX_SPLIT 8
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#define AT91_MB_RX_SPLIT 8
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#define AT91_MB_RX_LOW_LAST (AT91_MB_RX_SPLIT - 1)
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#define AT91_MB_RX_LOW_LAST (AT91_MB_RX_SPLIT - 1)
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#define AT91_MB_RX_LOW_MASK (AT91_MB_RX_MASK(AT91_MB_RX_SPLIT))
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#define AT91_MB_RX_LOW_MASK (AT91_MB_RX_MASK(AT91_MB_RX_SPLIT) & \
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~AT91_MB_RX_MASK(AT91_MB_RX_FIRST))
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#define AT91_MB_TX_NUM (1 << AT91_MB_TX_SHIFT)
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#define AT91_MB_TX_NUM (1 << AT91_MB_TX_SHIFT)
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#define AT91_MB_TX_FIRST (AT91_MB_RX_LAST + 1)
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#define AT91_MB_TX_FIRST (AT91_MB_RX_LAST + 1)
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@@ -168,6 +170,8 @@ struct at91_priv {
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struct clk *clk;
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struct clk *clk;
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struct at91_can_data *pdata;
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struct at91_can_data *pdata;
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canid_t mb0_id;
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};
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};
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static struct can_bittiming_const at91_bittiming_const = {
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static struct can_bittiming_const at91_bittiming_const = {
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@@ -220,6 +224,18 @@ static inline void set_mb_mode(const struct at91_priv *priv, unsigned int mb,
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set_mb_mode_prio(priv, mb, mode, 0);
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set_mb_mode_prio(priv, mb, mode, 0);
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}
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}
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static inline u32 at91_can_id_to_reg_mid(canid_t can_id)
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{
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u32 reg_mid;
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if (can_id & CAN_EFF_FLAG)
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reg_mid = (can_id & CAN_EFF_MASK) | AT91_MID_MIDE;
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else
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reg_mid = (can_id & CAN_SFF_MASK) << 18;
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return reg_mid;
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}
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/*
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/*
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* Swtich transceiver on or off
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* Swtich transceiver on or off
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*/
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*/
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@@ -233,12 +249,22 @@ static void at91_setup_mailboxes(struct net_device *dev)
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{
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{
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struct at91_priv *priv = netdev_priv(dev);
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struct at91_priv *priv = netdev_priv(dev);
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unsigned int i;
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unsigned int i;
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u32 reg_mid;
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/*
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/*
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* The first 12 mailboxes are used as a reception FIFO. The
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* Due to a chip bug (errata 50.2.6.3 & 50.3.5.3) the first
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* last mailbox is configured with overwrite option. The
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* mailbox is disabled. The next 11 mailboxes are used as a
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* overwrite flag indicates a FIFO overflow.
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* reception FIFO. The last mailbox is configured with
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* overwrite option. The overwrite flag indicates a FIFO
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* overflow.
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*/
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*/
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reg_mid = at91_can_id_to_reg_mid(priv->mb0_id);
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for (i = 0; i < AT91_MB_RX_FIRST; i++) {
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set_mb_mode(priv, i, AT91_MB_MODE_DISABLED);
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at91_write(priv, AT91_MID(i), reg_mid);
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at91_write(priv, AT91_MCR(i), 0x0); /* clear dlc */
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}
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for (i = AT91_MB_RX_FIRST; i < AT91_MB_RX_LAST; i++)
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for (i = AT91_MB_RX_FIRST; i < AT91_MB_RX_LAST; i++)
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set_mb_mode(priv, i, AT91_MB_MODE_RX);
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set_mb_mode(priv, i, AT91_MB_MODE_RX);
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set_mb_mode(priv, AT91_MB_RX_LAST, AT91_MB_MODE_RX_OVRWR);
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set_mb_mode(priv, AT91_MB_RX_LAST, AT91_MB_MODE_RX_OVRWR);
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@@ -254,7 +280,8 @@ static void at91_setup_mailboxes(struct net_device *dev)
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set_mb_mode_prio(priv, i, AT91_MB_MODE_TX, 0);
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set_mb_mode_prio(priv, i, AT91_MB_MODE_TX, 0);
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/* Reset tx and rx helper pointers */
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/* Reset tx and rx helper pointers */
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priv->tx_next = priv->tx_echo = priv->rx_next = 0;
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priv->tx_next = priv->tx_echo = 0;
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priv->rx_next = AT91_MB_RX_FIRST;
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}
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}
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static int at91_set_bittiming(struct net_device *dev)
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static int at91_set_bittiming(struct net_device *dev)
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@@ -372,12 +399,7 @@ static netdev_tx_t at91_start_xmit(struct sk_buff *skb, struct net_device *dev)
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netdev_err(dev, "BUG! TX buffer full when queue awake!\n");
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netdev_err(dev, "BUG! TX buffer full when queue awake!\n");
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return NETDEV_TX_BUSY;
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return NETDEV_TX_BUSY;
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}
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}
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reg_mid = at91_can_id_to_reg_mid(cf->can_id);
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if (cf->can_id & CAN_EFF_FLAG)
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reg_mid = (cf->can_id & CAN_EFF_MASK) | AT91_MID_MIDE;
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else
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reg_mid = (cf->can_id & CAN_SFF_MASK) << 18;
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reg_mcr = ((cf->can_id & CAN_RTR_FLAG) ? AT91_MCR_MRTR : 0) |
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reg_mcr = ((cf->can_id & CAN_RTR_FLAG) ? AT91_MCR_MRTR : 0) |
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(cf->can_dlc << 16) | AT91_MCR_MTCR;
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(cf->can_dlc << 16) | AT91_MCR_MTCR;
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@@ -539,27 +561,31 @@ static void at91_read_msg(struct net_device *dev, unsigned int mb)
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*
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*
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* Theory of Operation:
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* Theory of Operation:
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*
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*
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* 12 of the 16 mailboxes on the chip are reserved for RX. we split
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* 11 of the 16 mailboxes on the chip are reserved for RX. we split
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* them into 2 groups. The lower group holds 8 and upper 4 mailboxes.
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* them into 2 groups. The lower group holds 7 and upper 4 mailboxes.
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*
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*
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* Like it or not, but the chip always saves a received CAN message
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* Like it or not, but the chip always saves a received CAN message
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* into the first free mailbox it finds (starting with the
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* into the first free mailbox it finds (starting with the
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* lowest). This makes it very difficult to read the messages in the
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* lowest). This makes it very difficult to read the messages in the
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* right order from the chip. This is how we work around that problem:
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* right order from the chip. This is how we work around that problem:
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*
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*
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* The first message goes into mb nr. 0 and issues an interrupt. All
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* The first message goes into mb nr. 1 and issues an interrupt. All
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* rx ints are disabled in the interrupt handler and a napi poll is
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* rx ints are disabled in the interrupt handler and a napi poll is
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* scheduled. We read the mailbox, but do _not_ reenable the mb (to
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* scheduled. We read the mailbox, but do _not_ reenable the mb (to
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* receive another message).
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* receive another message).
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*
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*
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* lower mbxs upper
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* lower mbxs upper
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* ______^______ __^__
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* ____^______ __^__
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* / \ / \
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* / \ / \
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* +-+-+-+-+-+-+-+-++-+-+-+-+
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* +-+-+-+-+-+-+-+-++-+-+-+-+
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* |x|x|x|x|x|x|x|x|| | | | |
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* | |x|x|x|x|x|x|x|| | | | |
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* +-+-+-+-+-+-+-+-++-+-+-+-+
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* +-+-+-+-+-+-+-+-++-+-+-+-+
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* 0 0 0 0 0 0 0 0 0 0 1 1 \ mail
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* 0 0 0 0 0 0 0 0 0 0 1 1 \ mail
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* 0 1 2 3 4 5 6 7 8 9 0 1 / box
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* 0 1 2 3 4 5 6 7 8 9 0 1 / box
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* ^
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* |
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* \
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* unused, due to chip bug
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*
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*
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* The variable priv->rx_next points to the next mailbox to read a
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* The variable priv->rx_next points to the next mailbox to read a
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* message from. As long we're in the lower mailboxes we just read the
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* message from. As long we're in the lower mailboxes we just read the
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@@ -590,10 +616,10 @@ static int at91_poll_rx(struct net_device *dev, int quota)
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"order of incoming frames cannot be guaranteed\n");
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"order of incoming frames cannot be guaranteed\n");
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again:
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again:
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for (mb = find_next_bit(addr, AT91_MB_RX_NUM, priv->rx_next);
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for (mb = find_next_bit(addr, AT91_MB_RX_LAST + 1, priv->rx_next);
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mb < AT91_MB_RX_NUM && quota > 0;
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mb < AT91_MB_RX_LAST + 1 && quota > 0;
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reg_sr = at91_read(priv, AT91_SR),
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reg_sr = at91_read(priv, AT91_SR),
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mb = find_next_bit(addr, AT91_MB_RX_NUM, ++priv->rx_next)) {
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mb = find_next_bit(addr, AT91_MB_RX_LAST + 1, ++priv->rx_next)) {
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at91_read_msg(dev, mb);
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at91_read_msg(dev, mb);
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/* reactivate mailboxes */
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/* reactivate mailboxes */
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@@ -610,8 +636,8 @@ static int at91_poll_rx(struct net_device *dev, int quota)
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/* upper group completed, look again in lower */
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/* upper group completed, look again in lower */
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if (priv->rx_next > AT91_MB_RX_LOW_LAST &&
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if (priv->rx_next > AT91_MB_RX_LOW_LAST &&
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quota > 0 && mb >= AT91_MB_RX_NUM) {
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quota > 0 && mb > AT91_MB_RX_LAST) {
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priv->rx_next = 0;
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priv->rx_next = AT91_MB_RX_FIRST;
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goto again;
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goto again;
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}
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}
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@@ -1037,6 +1063,64 @@ static const struct net_device_ops at91_netdev_ops = {
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.ndo_start_xmit = at91_start_xmit,
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.ndo_start_xmit = at91_start_xmit,
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};
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};
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static ssize_t at91_sysfs_show_mb0_id(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct at91_priv *priv = netdev_priv(to_net_dev(dev));
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if (priv->mb0_id & CAN_EFF_FLAG)
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return snprintf(buf, PAGE_SIZE, "0x%08x\n", priv->mb0_id);
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else
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return snprintf(buf, PAGE_SIZE, "0x%03x\n", priv->mb0_id);
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}
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static ssize_t at91_sysfs_set_mb0_id(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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struct net_device *ndev = to_net_dev(dev);
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struct at91_priv *priv = netdev_priv(ndev);
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unsigned long can_id;
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ssize_t ret;
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int err;
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rtnl_lock();
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if (ndev->flags & IFF_UP) {
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ret = -EBUSY;
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goto out;
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}
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err = strict_strtoul(buf, 0, &can_id);
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if (err) {
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ret = err;
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goto out;
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}
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if (can_id & CAN_EFF_FLAG)
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can_id &= CAN_EFF_MASK | CAN_EFF_FLAG;
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else
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can_id &= CAN_SFF_MASK;
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priv->mb0_id = can_id;
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ret = count;
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out:
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rtnl_unlock();
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return ret;
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}
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static DEVICE_ATTR(mb0_id, S_IWUGO | S_IRUGO,
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at91_sysfs_show_mb0_id, at91_sysfs_set_mb0_id);
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static struct attribute *at91_sysfs_attrs[] = {
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&dev_attr_mb0_id.attr,
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NULL,
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};
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static struct attribute_group at91_sysfs_attr_group = {
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.attrs = at91_sysfs_attrs,
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};
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static int __devinit at91_can_probe(struct platform_device *pdev)
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static int __devinit at91_can_probe(struct platform_device *pdev)
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{
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{
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struct net_device *dev;
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struct net_device *dev;
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@@ -1082,6 +1166,7 @@ static int __devinit at91_can_probe(struct platform_device *pdev)
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dev->netdev_ops = &at91_netdev_ops;
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dev->netdev_ops = &at91_netdev_ops;
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dev->irq = irq;
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dev->irq = irq;
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dev->flags |= IFF_ECHO;
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dev->flags |= IFF_ECHO;
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dev->sysfs_groups[0] = &at91_sysfs_attr_group;
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priv = netdev_priv(dev);
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priv = netdev_priv(dev);
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priv->can.clock.freq = clk_get_rate(clk);
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priv->can.clock.freq = clk_get_rate(clk);
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@@ -1093,6 +1178,7 @@ static int __devinit at91_can_probe(struct platform_device *pdev)
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priv->dev = dev;
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priv->dev = dev;
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priv->clk = clk;
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priv->clk = clk;
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priv->pdata = pdev->dev.platform_data;
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priv->pdata = pdev->dev.platform_data;
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priv->mb0_id = 0x7ff;
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netif_napi_add(dev, &priv->napi, at91_poll, AT91_NAPI_WEIGHT);
|
netif_napi_add(dev, &priv->napi, at91_poll, AT91_NAPI_WEIGHT);
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||||||
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|
||||||
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Reference in New Issue
Block a user