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linux/drivers/net/can/cc770/cc770.c
Vincent Mailhol cc4b08c31b can: do not increase tx_bytes statistics for RTR frames 
The actual payload length of the CAN Remote Transmission Request (RTR)
frames is always 0, i.e. no payload is transmitted on the wire.
However, those RTR frames still use the DLC to indicate the length of
the requested frame.

As such, net_device_stats::tx_bytes should not be increased when
sending RTR frames.

The function can_get_echo_skb() already returns the correct length,
even for RTR frames (c.f. [1]). However, for historical reasons, the
drivers do not use can_get_echo_skb()'s return value and instead, most
of them store a temporary length (or dlc) in some local structure or
array. Using the return value of can_get_echo_skb() solves the
issue. After doing this, such length/dlc fields become unused and so
this patch does the adequate cleaning when needed.

This patch fixes all the CAN drivers.

Finally, can_get_echo_skb() is decorated with the __must_check
attribute in order to force future drivers to correctly use its return
value (else the compiler would emit a warning).

[1] commit ed3320cec279 ("can: dev: __can_get_echo_skb():
fix real payload length return value for RTR frames")

Link: https://lore.kernel.org/all/20211207121531.42941-6-mailhol.vincent@wanadoo.fr
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: Yasushi SHOJI <yashi@spacecubics.com>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Stephane Grosjean <s.grosjean@peak-system.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Tested-by: Jimmy Assarsson <extja@kvaser.com> # kvaser
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2
Tested-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2
[mkl: add conversion for grcan]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-01-05 12:09:05 +01:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Core driver for the CC770 and AN82527 CAN controllers
*
* Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/delay.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/can/platform/cc770.h>
#include "cc770.h"
MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION(KBUILD_MODNAME "CAN netdevice driver");
/*
* The CC770 is a CAN controller from Bosch, which is 100% compatible
* with the AN82527 from Intel, but with "bugs" being fixed and some
* additional functionality, mainly:
*
* 1. RX and TX error counters are readable.
* 2. Support of silent (listen-only) mode.
* 3. Message object 15 can receive all types of frames, also RTR and EFF.
*
* Details are available from Bosch's "CC770_Product_Info_2007-01.pdf",
* which explains in detail the compatibility between the CC770 and the
* 82527. This driver use the additional functionality 3. on real CC770
* devices. Unfortunately, the CC770 does still not store the message
* identifier of received remote transmission request frames and
* therefore it's set to 0.
*
* The message objects 1..14 can be used for TX and RX while the message
* objects 15 is optimized for RX. It has a shadow register for reliable
* data reception under heavy bus load. Therefore it makes sense to use
* this message object for the needed use case. The frame type (EFF/SFF)
* for the message object 15 can be defined via kernel module parameter
* "msgobj15_eff". If not equal 0, it will receive 29-bit EFF frames,
* otherwise 11 bit SFF messages.
*/
static int msgobj15_eff;
module_param(msgobj15_eff, int, 0444);
MODULE_PARM_DESC(msgobj15_eff, "Extended 29-bit frames for message object 15 "
"(default: 11-bit standard frames)");
static int i82527_compat;
module_param(i82527_compat, int, 0444);
MODULE_PARM_DESC(i82527_compat, "Strict Intel 82527 compatibility mode "
"without using additional functions");
/*
* This driver uses the last 5 message objects 11..15. The definitions
* and structure below allows to configure and assign them to the real
* message object.
*/
static unsigned char cc770_obj_flags[CC770_OBJ_MAX] = {
[CC770_OBJ_RX0] = CC770_OBJ_FLAG_RX,
[CC770_OBJ_RX1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_EFF,
[CC770_OBJ_RX_RTR0] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR,
[CC770_OBJ_RX_RTR1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR |
CC770_OBJ_FLAG_EFF,
[CC770_OBJ_TX] = 0,
};
static const struct can_bittiming_const cc770_bittiming_const = {
.name = KBUILD_MODNAME,
.tseg1_min = 1,
.tseg1_max = 16,
.tseg2_min = 1,
.tseg2_max = 8,
.sjw_max = 4,
.brp_min = 1,
.brp_max = 64,
.brp_inc = 1,
};
static inline int intid2obj(unsigned int intid)
{
if (intid == 2)
return 0;
else
return MSGOBJ_LAST + 2 - intid;
}
static void enable_all_objs(const struct net_device *dev)
{
struct cc770_priv *priv = netdev_priv(dev);
u8 msgcfg;
unsigned char obj_flags;
unsigned int o, mo;
for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
obj_flags = priv->obj_flags[o];
mo = obj2msgobj(o);
if (obj_flags & CC770_OBJ_FLAG_RX) {
/*
* We don't need extra objects for RTR and EFF if
* the additional CC770 functions are enabled.
*/
if (priv->control_normal_mode & CTRL_EAF) {
if (o > 0)
continue;
netdev_dbg(dev, "Message object %d for "
"RX data, RTR, SFF and EFF\n", mo);
} else {
netdev_dbg(dev,
"Message object %d for RX %s %s\n",
mo, obj_flags & CC770_OBJ_FLAG_RTR ?
"RTR" : "data",
obj_flags & CC770_OBJ_FLAG_EFF ?
"EFF" : "SFF");
}
if (obj_flags & CC770_OBJ_FLAG_EFF)
msgcfg = MSGCFG_XTD;
else
msgcfg = 0;
if (obj_flags & CC770_OBJ_FLAG_RTR)
msgcfg |= MSGCFG_DIR;
cc770_write_reg(priv, msgobj[mo].config, msgcfg);
cc770_write_reg(priv, msgobj[mo].ctrl0,
MSGVAL_SET | TXIE_RES |
RXIE_SET | INTPND_RES);
if (obj_flags & CC770_OBJ_FLAG_RTR)
cc770_write_reg(priv, msgobj[mo].ctrl1,
NEWDAT_RES | CPUUPD_SET |
TXRQST_RES | RMTPND_RES);
else
cc770_write_reg(priv, msgobj[mo].ctrl1,
NEWDAT_RES | MSGLST_RES |
TXRQST_RES | RMTPND_RES);
} else {
netdev_dbg(dev, "Message object %d for "
"TX data, RTR, SFF and EFF\n", mo);
cc770_write_reg(priv, msgobj[mo].ctrl1,
RMTPND_RES | TXRQST_RES |
CPUUPD_RES | NEWDAT_RES);
cc770_write_reg(priv, msgobj[mo].ctrl0,
MSGVAL_RES | TXIE_RES |
RXIE_RES | INTPND_RES);
}
}
}
static void disable_all_objs(const struct cc770_priv *priv)
{
int o, mo;
for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
mo = obj2msgobj(o);
if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX) {
if (o > 0 && priv->control_normal_mode & CTRL_EAF)
continue;
cc770_write_reg(priv, msgobj[mo].ctrl1,
NEWDAT_RES | MSGLST_RES |
TXRQST_RES | RMTPND_RES);
cc770_write_reg(priv, msgobj[mo].ctrl0,
MSGVAL_RES | TXIE_RES |
RXIE_RES | INTPND_RES);
} else {
/* Clear message object for send */
cc770_write_reg(priv, msgobj[mo].ctrl1,
RMTPND_RES | TXRQST_RES |
CPUUPD_RES | NEWDAT_RES);
cc770_write_reg(priv, msgobj[mo].ctrl0,
MSGVAL_RES | TXIE_RES |
RXIE_RES | INTPND_RES);
}
}
}
static void set_reset_mode(struct net_device *dev)
{
struct cc770_priv *priv = netdev_priv(dev);
/* Enable configuration and puts chip in bus-off, disable interrupts */
cc770_write_reg(priv, control, CTRL_CCE | CTRL_INI);
priv->can.state = CAN_STATE_STOPPED;
/* Clear interrupts */
cc770_read_reg(priv, interrupt);
/* Clear status register */
cc770_write_reg(priv, status, 0);
/* Disable all used message objects */
disable_all_objs(priv);
}
static void set_normal_mode(struct net_device *dev)
{
struct cc770_priv *priv = netdev_priv(dev);
/* Clear interrupts */
cc770_read_reg(priv, interrupt);
/* Clear status register and pre-set last error code */
cc770_write_reg(priv, status, STAT_LEC_MASK);
/* Enable all used message objects*/
enable_all_objs(dev);
/*
* Clear bus-off, interrupts only for errors,
* not for status change
*/
cc770_write_reg(priv, control, priv->control_normal_mode);
priv->can.state = CAN_STATE_ERROR_ACTIVE;
}
static void chipset_init(struct cc770_priv *priv)
{
int mo, id, data;
/* Enable configuration and put chip in bus-off, disable interrupts */
cc770_write_reg(priv, control, (CTRL_CCE | CTRL_INI));
/* Set CLKOUT divider and slew rates */
cc770_write_reg(priv, clkout, priv->clkout);
/* Configure CPU interface / CLKOUT enable */
cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
/* Set bus configuration */
cc770_write_reg(priv, bus_config, priv->bus_config);
/* Clear interrupts */
cc770_read_reg(priv, interrupt);
/* Clear status register */
cc770_write_reg(priv, status, 0);
/* Clear and invalidate message objects */
for (mo = MSGOBJ_FIRST; mo <= MSGOBJ_LAST; mo++) {
cc770_write_reg(priv, msgobj[mo].ctrl0,
INTPND_UNC | RXIE_RES |
TXIE_RES | MSGVAL_RES);
cc770_write_reg(priv, msgobj[mo].ctrl0,
INTPND_RES | RXIE_RES |
TXIE_RES | MSGVAL_RES);
cc770_write_reg(priv, msgobj[mo].ctrl1,
NEWDAT_RES | MSGLST_RES |
TXRQST_RES | RMTPND_RES);
for (data = 0; data < 8; data++)
cc770_write_reg(priv, msgobj[mo].data[data], 0);
for (id = 0; id < 4; id++)
cc770_write_reg(priv, msgobj[mo].id[id], 0);
cc770_write_reg(priv, msgobj[mo].config, 0);
}
/* Set all global ID masks to "don't care" */
cc770_write_reg(priv, global_mask_std[0], 0);
cc770_write_reg(priv, global_mask_std[1], 0);
cc770_write_reg(priv, global_mask_ext[0], 0);
cc770_write_reg(priv, global_mask_ext[1], 0);
cc770_write_reg(priv, global_mask_ext[2], 0);
cc770_write_reg(priv, global_mask_ext[3], 0);
}
static int cc770_probe_chip(struct net_device *dev)
{
struct cc770_priv *priv = netdev_priv(dev);
/* Enable configuration, put chip in bus-off, disable ints */
cc770_write_reg(priv, control, CTRL_CCE | CTRL_EAF | CTRL_INI);
/* Configure cpu interface / CLKOUT disable */
cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
/*
* Check if hardware reset is still inactive or maybe there
* is no chip in this address space
*/
if (cc770_read_reg(priv, cpu_interface) & CPUIF_RST) {
netdev_info(dev, "probing @0x%p failed (reset)\n",
priv->reg_base);
return -ENODEV;
}
/* Write and read back test pattern (some arbitrary values) */
cc770_write_reg(priv, msgobj[1].data[1], 0x25);
cc770_write_reg(priv, msgobj[2].data[3], 0x52);
cc770_write_reg(priv, msgobj[10].data[6], 0xc3);
if ((cc770_read_reg(priv, msgobj[1].data[1]) != 0x25) ||
(cc770_read_reg(priv, msgobj[2].data[3]) != 0x52) ||
(cc770_read_reg(priv, msgobj[10].data[6]) != 0xc3)) {
netdev_info(dev, "probing @0x%p failed (pattern)\n",
priv->reg_base);
return -ENODEV;
}
/* Check if this chip is a CC770 supporting additional functions */
if (cc770_read_reg(priv, control) & CTRL_EAF)
priv->control_normal_mode |= CTRL_EAF;
return 0;
}
static void cc770_start(struct net_device *dev)
{
struct cc770_priv *priv = netdev_priv(dev);
/* leave reset mode */
if (priv->can.state != CAN_STATE_STOPPED)
set_reset_mode(dev);
/* leave reset mode */
set_normal_mode(dev);
}
static int cc770_set_mode(struct net_device *dev, enum can_mode mode)
{
switch (mode) {
case CAN_MODE_START:
cc770_start(dev);
netif_wake_queue(dev);
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static int cc770_set_bittiming(struct net_device *dev)
{
struct cc770_priv *priv = netdev_priv(dev);
struct can_bittiming *bt = &priv->can.bittiming;
u8 btr0, btr1;
btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
(((bt->phase_seg2 - 1) & 0x7) << 4);
if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
btr1 |= 0x80;
netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
cc770_write_reg(priv, bit_timing_0, btr0);
cc770_write_reg(priv, bit_timing_1, btr1);
return 0;
}
static int cc770_get_berr_counter(const struct net_device *dev,
struct can_berr_counter *bec)
{
struct cc770_priv *priv = netdev_priv(dev);
bec->txerr = cc770_read_reg(priv, tx_error_counter);
bec->rxerr = cc770_read_reg(priv, rx_error_counter);
return 0;
}
static void cc770_tx(struct net_device *dev, int mo)
{
struct cc770_priv *priv = netdev_priv(dev);
struct can_frame *cf = (struct can_frame *)priv->tx_skb->data;
u8 dlc, rtr;
u32 id;
int i;
dlc = cf->len;
id = cf->can_id;
rtr = cf->can_id & CAN_RTR_FLAG ? 0 : MSGCFG_DIR;
cc770_write_reg(priv, msgobj[mo].ctrl0,
MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
cc770_write_reg(priv, msgobj[mo].ctrl1,
RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
if (id & CAN_EFF_FLAG) {
id &= CAN_EFF_MASK;
cc770_write_reg(priv, msgobj[mo].config,
(dlc << 4) | rtr | MSGCFG_XTD);
cc770_write_reg(priv, msgobj[mo].id[3], id << 3);
cc770_write_reg(priv, msgobj[mo].id[2], id >> 5);
cc770_write_reg(priv, msgobj[mo].id[1], id >> 13);
cc770_write_reg(priv, msgobj[mo].id[0], id >> 21);
} else {
id &= CAN_SFF_MASK;
cc770_write_reg(priv, msgobj[mo].config, (dlc << 4) | rtr);
cc770_write_reg(priv, msgobj[mo].id[0], id >> 3);
cc770_write_reg(priv, msgobj[mo].id[1], id << 5);
}
for (i = 0; i < dlc; i++)
cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]);
cc770_write_reg(priv, msgobj[mo].ctrl1,
RMTPND_UNC | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);
cc770_write_reg(priv, msgobj[mo].ctrl0,
MSGVAL_SET | TXIE_SET | RXIE_SET | INTPND_UNC);
}
static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct cc770_priv *priv = netdev_priv(dev);
unsigned int mo = obj2msgobj(CC770_OBJ_TX);
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
netif_stop_queue(dev);
if ((cc770_read_reg(priv,
msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
netdev_err(dev, "TX register is still occupied!\n");
return NETDEV_TX_BUSY;
}
priv->tx_skb = skb;
cc770_tx(dev, mo);
return NETDEV_TX_OK;
}
static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1)
{
struct cc770_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
struct can_frame *cf;
struct sk_buff *skb;
u8 config;
u32 id;
int i;
skb = alloc_can_skb(dev, &cf);
if (!skb)
return;
config = cc770_read_reg(priv, msgobj[mo].config);
if (ctrl1 & RMTPND_SET) {
/*
* Unfortunately, the chip does not store the real message
* identifier of the received remote transmission request
* frame. Therefore we set it to 0.
*/
cf->can_id = CAN_RTR_FLAG;
if (config & MSGCFG_XTD)
cf->can_id |= CAN_EFF_FLAG;
cf->len = 0;
} else {
if (config & MSGCFG_XTD) {
id = cc770_read_reg(priv, msgobj[mo].id[3]);
id |= cc770_read_reg(priv, msgobj[mo].id[2]) << 8;
id |= cc770_read_reg(priv, msgobj[mo].id[1]) << 16;
id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 24;
id >>= 3;
id |= CAN_EFF_FLAG;
} else {
id = cc770_read_reg(priv, msgobj[mo].id[1]);
id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 8;
id >>= 5;
}
cf->can_id = id;
cf->len = can_cc_dlc2len((config & 0xf0) >> 4);
for (i = 0; i < cf->len; i++)
cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]);
stats->rx_bytes += cf->len;
}
stats->rx_packets++;
netif_rx(skb);
}
static int cc770_err(struct net_device *dev, u8 status)
{
struct cc770_priv *priv = netdev_priv(dev);
struct can_frame *cf;
struct sk_buff *skb;
u8 lec;
netdev_dbg(dev, "status interrupt (%#x)\n", status);
skb = alloc_can_err_skb(dev, &cf);
if (!skb)
return -ENOMEM;
/* Use extended functions of the CC770 */
if (priv->control_normal_mode & CTRL_EAF) {
cf->data[6] = cc770_read_reg(priv, tx_error_counter);
cf->data[7] = cc770_read_reg(priv, rx_error_counter);
}
if (status & STAT_BOFF) {
/* Disable interrupts */
cc770_write_reg(priv, control, CTRL_INI);
cf->can_id |= CAN_ERR_BUSOFF;
priv->can.state = CAN_STATE_BUS_OFF;
priv->can.can_stats.bus_off++;
can_bus_off(dev);
} else if (status & STAT_WARN) {
cf->can_id |= CAN_ERR_CRTL;
/* Only the CC770 does show error passive */
if (cf->data[7] > 127) {
cf->data[1] = CAN_ERR_CRTL_RX_PASSIVE |
CAN_ERR_CRTL_TX_PASSIVE;
priv->can.state = CAN_STATE_ERROR_PASSIVE;
priv->can.can_stats.error_passive++;
} else {
cf->data[1] = CAN_ERR_CRTL_RX_WARNING |
CAN_ERR_CRTL_TX_WARNING;
priv->can.state = CAN_STATE_ERROR_WARNING;
priv->can.can_stats.error_warning++;
}
} else {
/* Back to error active */
cf->can_id |= CAN_ERR_PROT;
cf->data[2] = CAN_ERR_PROT_ACTIVE;
priv->can.state = CAN_STATE_ERROR_ACTIVE;
}
lec = status & STAT_LEC_MASK;
if (lec < 7 && lec > 0) {
if (lec == STAT_LEC_ACK) {
cf->can_id |= CAN_ERR_ACK;
} else {
cf->can_id |= CAN_ERR_PROT;
switch (lec) {
case STAT_LEC_STUFF:
cf->data[2] |= CAN_ERR_PROT_STUFF;
break;
case STAT_LEC_FORM:
cf->data[2] |= CAN_ERR_PROT_FORM;
break;
case STAT_LEC_BIT1:
cf->data[2] |= CAN_ERR_PROT_BIT1;
break;
case STAT_LEC_BIT0:
cf->data[2] |= CAN_ERR_PROT_BIT0;
break;
case STAT_LEC_CRC:
cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
break;
}
}
}
netif_rx(skb);
return 0;
}
static int cc770_status_interrupt(struct net_device *dev)
{
struct cc770_priv *priv = netdev_priv(dev);
u8 status;
status = cc770_read_reg(priv, status);
/* Reset the status register including RXOK and TXOK */
cc770_write_reg(priv, status, STAT_LEC_MASK);
if (status & (STAT_WARN | STAT_BOFF) ||
(status & STAT_LEC_MASK) != STAT_LEC_MASK) {
cc770_err(dev, status);
return status & STAT_BOFF;
}
return 0;
}
static void cc770_rx_interrupt(struct net_device *dev, unsigned int o)
{
struct cc770_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
unsigned int mo = obj2msgobj(o);
u8 ctrl1;
int n = CC770_MAX_MSG;
while (n--) {
ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
if (!(ctrl1 & NEWDAT_SET)) {
/* Check for RTR if additional functions are enabled */
if (priv->control_normal_mode & CTRL_EAF) {
if (!(cc770_read_reg(priv, msgobj[mo].ctrl0) &
INTPND_SET))
break;
} else {
break;
}
}
if (ctrl1 & MSGLST_SET) {
stats->rx_over_errors++;
stats->rx_errors++;
}
if (mo < MSGOBJ_LAST)
cc770_write_reg(priv, msgobj[mo].ctrl1,
NEWDAT_RES | MSGLST_RES |
TXRQST_UNC | RMTPND_UNC);
cc770_rx(dev, mo, ctrl1);
cc770_write_reg(priv, msgobj[mo].ctrl0,
MSGVAL_SET | TXIE_RES |
RXIE_SET | INTPND_RES);
cc770_write_reg(priv, msgobj[mo].ctrl1,
NEWDAT_RES | MSGLST_RES |
TXRQST_RES | RMTPND_RES);
}
}
static void cc770_rtr_interrupt(struct net_device *dev, unsigned int o)
{
struct cc770_priv *priv = netdev_priv(dev);
unsigned int mo = obj2msgobj(o);
u8 ctrl0, ctrl1;
int n = CC770_MAX_MSG;
while (n--) {
ctrl0 = cc770_read_reg(priv, msgobj[mo].ctrl0);
if (!(ctrl0 & INTPND_SET))
break;
ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
cc770_rx(dev, mo, ctrl1);
cc770_write_reg(priv, msgobj[mo].ctrl0,
MSGVAL_SET | TXIE_RES |
RXIE_SET | INTPND_RES);
cc770_write_reg(priv, msgobj[mo].ctrl1,
NEWDAT_RES | CPUUPD_SET |
TXRQST_RES | RMTPND_RES);
}
}
static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
{
struct cc770_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
unsigned int mo = obj2msgobj(o);
u8 ctrl1;
ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
cc770_write_reg(priv, msgobj[mo].ctrl0,
MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
cc770_write_reg(priv, msgobj[mo].ctrl1,
RMTPND_RES | TXRQST_RES | MSGLST_RES | NEWDAT_RES);
if (unlikely(!priv->tx_skb)) {
netdev_err(dev, "missing tx skb in tx interrupt\n");
return;
}
if (unlikely(ctrl1 & MSGLST_SET)) {
stats->rx_over_errors++;
stats->rx_errors++;
}
/* When the CC770 is sending an RTR message and it receives a regular
* message that matches the id of the RTR message, it will overwrite the
* outgoing message in the TX register. When this happens we must
* process the received message and try to transmit the outgoing skb
* again.
*/
if (unlikely(ctrl1 & NEWDAT_SET)) {
cc770_rx(dev, mo, ctrl1);
cc770_tx(dev, mo);
return;
}
can_put_echo_skb(priv->tx_skb, dev, 0, 0);
stats->tx_bytes += can_get_echo_skb(dev, 0, NULL);
stats->tx_packets++;
priv->tx_skb = NULL;
netif_wake_queue(dev);
}
static irqreturn_t cc770_interrupt(int irq, void *dev_id)
{
struct net_device *dev = (struct net_device *)dev_id;
struct cc770_priv *priv = netdev_priv(dev);
u8 intid;
int o, n = 0;
/* Shared interrupts and IRQ off? */
if (priv->can.state == CAN_STATE_STOPPED)
return IRQ_NONE;
if (priv->pre_irq)
priv->pre_irq(priv);
while (n < CC770_MAX_IRQ) {
/* Read the highest pending interrupt request */
intid = cc770_read_reg(priv, interrupt);
if (!intid)
break;
n++;
if (intid == 1) {
/* Exit in case of bus-off */
if (cc770_status_interrupt(dev))
break;
} else {
o = intid2obj(intid);
if (o >= CC770_OBJ_MAX) {
netdev_err(dev, "Unexpected interrupt id %d\n",
intid);
continue;
}
if (priv->obj_flags[o] & CC770_OBJ_FLAG_RTR)
cc770_rtr_interrupt(dev, o);
else if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX)
cc770_rx_interrupt(dev, o);
else
cc770_tx_interrupt(dev, o);
}
}
if (priv->post_irq)
priv->post_irq(priv);
if (n >= CC770_MAX_IRQ)
netdev_dbg(dev, "%d messages handled in ISR", n);
return (n) ? IRQ_HANDLED : IRQ_NONE;
}
static int cc770_open(struct net_device *dev)
{
struct cc770_priv *priv = netdev_priv(dev);
int err;
/* set chip into reset mode */
set_reset_mode(dev);
/* common open */
err = open_candev(dev);
if (err)
return err;
err = request_irq(dev->irq, &cc770_interrupt, priv->irq_flags,
dev->name, dev);
if (err) {
close_candev(dev);
return -EAGAIN;
}
/* init and start chip */
cc770_start(dev);
netif_start_queue(dev);
return 0;
}
static int cc770_close(struct net_device *dev)
{
netif_stop_queue(dev);
set_reset_mode(dev);
free_irq(dev->irq, dev);
close_candev(dev);
return 0;
}
struct net_device *alloc_cc770dev(int sizeof_priv)
{
struct net_device *dev;
struct cc770_priv *priv;
dev = alloc_candev(sizeof(struct cc770_priv) + sizeof_priv,
CC770_ECHO_SKB_MAX);
if (!dev)
return NULL;
priv = netdev_priv(dev);
priv->dev = dev;
priv->can.bittiming_const = &cc770_bittiming_const;
priv->can.do_set_bittiming = cc770_set_bittiming;
priv->can.do_set_mode = cc770_set_mode;
priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
priv->tx_skb = NULL;
memcpy(priv->obj_flags, cc770_obj_flags, sizeof(cc770_obj_flags));
if (sizeof_priv)
priv->priv = (void *)priv + sizeof(struct cc770_priv);
return dev;
}
EXPORT_SYMBOL_GPL(alloc_cc770dev);
void free_cc770dev(struct net_device *dev)
{
free_candev(dev);
}
EXPORT_SYMBOL_GPL(free_cc770dev);
static const struct net_device_ops cc770_netdev_ops = {
.ndo_open = cc770_open,
.ndo_stop = cc770_close,
.ndo_start_xmit = cc770_start_xmit,
.ndo_change_mtu = can_change_mtu,
};
int register_cc770dev(struct net_device *dev)
{
struct cc770_priv *priv = netdev_priv(dev);
int err;
err = cc770_probe_chip(dev);
if (err)
return err;
dev->netdev_ops = &cc770_netdev_ops;
dev->flags |= IFF_ECHO; /* we support local echo */
/* Should we use additional functions? */
if (!i82527_compat && priv->control_normal_mode & CTRL_EAF) {
priv->can.do_get_berr_counter = cc770_get_berr_counter;
priv->control_normal_mode = CTRL_IE | CTRL_EAF | CTRL_EIE;
netdev_dbg(dev, "i82527 mode with additional functions\n");
} else {
priv->control_normal_mode = CTRL_IE | CTRL_EIE;
netdev_dbg(dev, "strict i82527 compatibility mode\n");
}
chipset_init(priv);
set_reset_mode(dev);
return register_candev(dev);
}
EXPORT_SYMBOL_GPL(register_cc770dev);
void unregister_cc770dev(struct net_device *dev)
{
set_reset_mode(dev);
unregister_candev(dev);
}
EXPORT_SYMBOL_GPL(unregister_cc770dev);
static __init int cc770_init(void)
{
if (msgobj15_eff) {
cc770_obj_flags[CC770_OBJ_RX0] |= CC770_OBJ_FLAG_EFF;
cc770_obj_flags[CC770_OBJ_RX1] &= ~CC770_OBJ_FLAG_EFF;
}
pr_info("CAN netdevice driver\n");
return 0;
}
module_init(cc770_init);
static __exit void cc770_exit(void)
{
pr_info("driver removed\n");
}
module_exit(cc770_exit);
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