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/* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface
*
* Copyright(C) Timesys Corporation 2016
*
* Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver
* Copyright 2009 Christian Pellegrin EVOL S.r.l.
* Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
* Copyright 2006 Arcom Control Systems Ltd.
*
* Based on CAN bus driver for the CCAN controller written by
* - Sascha Hauer, Marc Kleine-Budde, Pengutronix
* - Simon Kallweit, intefo AG
* Copyright 2007
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/can/core.h>
#include <linux/can/dev.h>
#include <linux/can/led.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/freezer.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/uaccess.h>
#define HI3110_MASTER_RESET 0x56
#define HI3110_READ_CTRL0 0xD2
#define HI3110_READ_CTRL1 0xD4
#define HI3110_READ_STATF 0xE2
#define HI3110_WRITE_CTRL0 0x14
#define HI3110_WRITE_CTRL1 0x16
#define HI3110_WRITE_INTE 0x1C
#define HI3110_WRITE_BTR0 0x18
#define HI3110_WRITE_BTR1 0x1A
#define HI3110_READ_BTR0 0xD6
#define HI3110_READ_BTR1 0xD8
#define HI3110_READ_INTF 0xDE
#define HI3110_READ_ERR 0xDC
#define HI3110_READ_FIFO_WOTIME 0x48
#define HI3110_WRITE_FIFO 0x12
#define HI3110_READ_MESSTAT 0xDA
#define HI3110_READ_REC 0xEA
#define HI3110_READ_TEC 0xEC
#define HI3110_CTRL0_MODE_MASK (7 << 5)
#define HI3110_CTRL0_NORMAL_MODE (0 << 5)
#define HI3110_CTRL0_LOOPBACK_MODE (1 << 5)
#define HI3110_CTRL0_MONITOR_MODE (2 << 5)
#define HI3110_CTRL0_SLEEP_MODE (3 << 5)
#define HI3110_CTRL0_INIT_MODE (4 << 5)
#define HI3110_CTRL1_TXEN BIT(7)
#define HI3110_INT_RXTMP BIT(7)
#define HI3110_INT_RXFIFO BIT(6)
#define HI3110_INT_TXCPLT BIT(5)
#define HI3110_INT_BUSERR BIT(4)
#define HI3110_INT_MCHG BIT(3)
#define HI3110_INT_WAKEUP BIT(2)
#define HI3110_INT_F1MESS BIT(1)
#define HI3110_INT_F0MESS BIT(0)
#define HI3110_ERR_BUSOFF BIT(7)
#define HI3110_ERR_TXERRP BIT(6)
#define HI3110_ERR_RXERRP BIT(5)
#define HI3110_ERR_BITERR BIT(4)
#define HI3110_ERR_FRMERR BIT(3)
#define HI3110_ERR_CRCERR BIT(2)
#define HI3110_ERR_ACKERR BIT(1)
#define HI3110_ERR_STUFERR BIT(0)
#define HI3110_ERR_PROTOCOL_MASK (0x1F)
#define HI3110_ERR_PASSIVE_MASK (0x60)
#define HI3110_STAT_RXFMTY BIT(1)
#define HI3110_STAT_BUSOFF BIT(2)
#define HI3110_STAT_ERRP BIT(3)
#define HI3110_STAT_ERRW BIT(4)
#define HI3110_STAT_TXMTY BIT(7)
#define HI3110_BTR0_SJW_SHIFT 6
#define HI3110_BTR0_BRP_SHIFT 0
#define HI3110_BTR1_SAMP_3PERBIT (1 << 7)
#define HI3110_BTR1_SAMP_1PERBIT (0 << 7)
#define HI3110_BTR1_TSEG2_SHIFT 4
#define HI3110_BTR1_TSEG1_SHIFT 0
#define HI3110_FIFO_WOTIME_TAG_OFF 0
#define HI3110_FIFO_WOTIME_ID_OFF 1
#define HI3110_FIFO_WOTIME_DLC_OFF 5
#define HI3110_FIFO_WOTIME_DAT_OFF 6
#define HI3110_FIFO_WOTIME_TAG_IDE BIT(7)
#define HI3110_FIFO_WOTIME_ID_RTR BIT(0)
#define HI3110_FIFO_TAG_OFF 0
#define HI3110_FIFO_ID_OFF 1
#define HI3110_FIFO_STD_DLC_OFF 3
#define HI3110_FIFO_STD_DATA_OFF 4
#define HI3110_FIFO_EXT_DLC_OFF 5
#define HI3110_FIFO_EXT_DATA_OFF 6
#define HI3110_CAN_MAX_DATA_LEN 8
#define HI3110_RX_BUF_LEN 15
#define HI3110_TX_STD_BUF_LEN 12
#define HI3110_TX_EXT_BUF_LEN 14
#define HI3110_CAN_FRAME_MAX_BITS 128
#define HI3110_EFF_FLAGS 0x18 /* IDE + SRR */
#define HI3110_TX_ECHO_SKB_MAX 1
#define HI3110_OST_DELAY_MS (10)
#define DEVICE_NAME "hi3110"
static int hi3110_enable_dma = 1; /* Enable SPI DMA. Default: 1 (On) */
module_param(hi3110_enable_dma, int, 0444);
MODULE_PARM_DESC(hi3110_enable_dma, "Enable SPI DMA. Default: 1 (On)");
static const struct can_bittiming_const hi3110_bittiming_const = {
.name = DEVICE_NAME,
.tseg1_min = 2,
.tseg1_max = 16,
.tseg2_min = 2,
.tseg2_max = 8,
.sjw_max = 4,
.brp_min = 1,
.brp_max = 64,
.brp_inc = 1,
};
enum hi3110_model {
CAN_HI3110_HI3110 = 0x3110,
};
struct hi3110_priv {
struct can_priv can;
struct net_device *net;
struct spi_device *spi;
enum hi3110_model model;
struct mutex hi3110_lock; /* SPI device lock */
u8 *spi_tx_buf;
u8 *spi_rx_buf;
dma_addr_t spi_tx_dma;
dma_addr_t spi_rx_dma;
struct sk_buff *tx_skb;
int tx_len;
struct workqueue_struct *wq;
struct work_struct tx_work;
struct work_struct restart_work;
int force_quit;
int after_suspend;
#define HI3110_AFTER_SUSPEND_UP 1
#define HI3110_AFTER_SUSPEND_DOWN 2
#define HI3110_AFTER_SUSPEND_POWER 4
#define HI3110_AFTER_SUSPEND_RESTART 8
int restart_tx;
struct regulator *power;
struct regulator *transceiver;
struct clk *clk;
};
static void hi3110_clean(struct net_device *net)
{
struct hi3110_priv *priv = netdev_priv(net);
if (priv->tx_skb || priv->tx_len)
net->stats.tx_errors++;
if (priv->tx_skb)
dev_kfree_skb(priv->tx_skb);
if (priv->tx_len)
can_free_echo_skb(priv->net, 0);
priv->tx_skb = NULL;
priv->tx_len = 0;
}
/* Note about handling of error return of hi3110_spi_trans: accessing
* registers via SPI is not really different conceptually than using
* normal I/O assembler instructions, although it's much more
* complicated from a practical POV. So it's not advisable to always
* check the return value of this function. Imagine that every
* read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
* error();", it would be a great mess (well there are some situation
* when exception handling C++ like could be useful after all). So we
* just check that transfers are OK at the beginning of our
* conversation with the chip and to avoid doing really nasty things
* (like injecting bogus packets in the network stack).
*/
static int hi3110_spi_trans(struct spi_device *spi, int len)
{
struct hi3110_priv *priv = spi_get_drvdata(spi);
struct spi_transfer t = {
.tx_buf = priv->spi_tx_buf,
.rx_buf = priv->spi_rx_buf,
.len = len,
.cs_change = 0,
};
struct spi_message m;
int ret;
spi_message_init(&m);
if (hi3110_enable_dma) {
t.tx_dma = priv->spi_tx_dma;
t.rx_dma = priv->spi_rx_dma;
m.is_dma_mapped = 1;
}
spi_message_add_tail(&t, &m);
ret = spi_sync(spi, &m);
if (ret)
dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
return ret;
}
static u8 hi3110_cmd(struct spi_device *spi, u8 command)
{
struct hi3110_priv *priv = spi_get_drvdata(spi);
priv->spi_tx_buf[0] = command;
dev_dbg(&spi->dev, "hi3110_cmd: %02X\n", command);
return hi3110_spi_trans(spi, 1);
}
static u8 hi3110_read(struct spi_device *spi, u8 command)
{
struct hi3110_priv *priv = spi_get_drvdata(spi);
u8 val = 0;
priv->spi_tx_buf[0] = command;
hi3110_spi_trans(spi, 2);
val = priv->spi_rx_buf[1];
return val;
}
static void hi3110_write(struct spi_device *spi, u8 reg, u8 val)
{
struct hi3110_priv *priv = spi_get_drvdata(spi);
priv->spi_tx_buf[0] = reg;
priv->spi_tx_buf[1] = val;
hi3110_spi_trans(spi, 2);
}
static void hi3110_hw_tx_frame(struct spi_device *spi, u8 *buf, int len)
{
struct hi3110_priv *priv = spi_get_drvdata(spi);
priv->spi_tx_buf[0] = HI3110_WRITE_FIFO;
memcpy(priv->spi_tx_buf + 1, buf, len);
hi3110_spi_trans(spi, len + 1);
}
static void hi3110_hw_tx(struct spi_device *spi, struct can_frame *frame)
{
u8 buf[HI3110_TX_EXT_BUF_LEN];
buf[HI3110_FIFO_TAG_OFF] = 0;
if (frame->can_id & CAN_EFF_FLAG) {
/* Extended frame */
buf[HI3110_FIFO_ID_OFF] = (frame->can_id & CAN_EFF_MASK) >> 21;
buf[HI3110_FIFO_ID_OFF + 1] =
(((frame->can_id & CAN_EFF_MASK) >> 13) & 0xe0) |
HI3110_EFF_FLAGS |
(((frame->can_id & CAN_EFF_MASK) >> 15) & 0x07);
buf[HI3110_FIFO_ID_OFF + 2] =
(frame->can_id & CAN_EFF_MASK) >> 7;
buf[HI3110_FIFO_ID_OFF + 3] =
((frame->can_id & CAN_EFF_MASK) << 1) |
((frame->can_id & CAN_RTR_FLAG) ? 1 : 0);
buf[HI3110_FIFO_EXT_DLC_OFF] = frame->can_dlc;
memcpy(buf + HI3110_FIFO_EXT_DATA_OFF,
frame->data, frame->can_dlc);
hi3110_hw_tx_frame(spi, buf, HI3110_TX_EXT_BUF_LEN -
(HI3110_CAN_MAX_DATA_LEN - frame->can_dlc));
} else {
/* Standard frame */
buf[HI3110_FIFO_ID_OFF] = (frame->can_id & CAN_SFF_MASK) >> 3;
buf[HI3110_FIFO_ID_OFF + 1] =
((frame->can_id & CAN_SFF_MASK) << 5) |
((frame->can_id & CAN_RTR_FLAG) ? (1 << 4) : 0);
buf[HI3110_FIFO_STD_DLC_OFF] = frame->can_dlc;
memcpy(buf + HI3110_FIFO_STD_DATA_OFF,
frame->data, frame->can_dlc);
hi3110_hw_tx_frame(spi, buf, HI3110_TX_STD_BUF_LEN -
(HI3110_CAN_MAX_DATA_LEN - frame->can_dlc));
}
}
static void hi3110_hw_rx_frame(struct spi_device *spi, u8 *buf)
{
struct hi3110_priv *priv = spi_get_drvdata(spi);
priv->spi_tx_buf[0] = HI3110_READ_FIFO_WOTIME;
hi3110_spi_trans(spi, HI3110_RX_BUF_LEN);
memcpy(buf, priv->spi_rx_buf + 1, HI3110_RX_BUF_LEN - 1);
}
static void hi3110_hw_rx(struct spi_device *spi)
{
struct hi3110_priv *priv = spi_get_drvdata(spi);
struct sk_buff *skb;
struct can_frame *frame;
u8 buf[HI3110_RX_BUF_LEN - 1];
skb = alloc_can_skb(priv->net, &frame);
if (!skb) {
priv->net->stats.rx_dropped++;
return;
}
hi3110_hw_rx_frame(spi, buf);
if (buf[HI3110_FIFO_WOTIME_TAG_OFF] & HI3110_FIFO_WOTIME_TAG_IDE) {
/* IDE is recessive (1), indicating extended 29-bit frame */
frame->can_id = CAN_EFF_FLAG;
frame->can_id |=
(buf[HI3110_FIFO_WOTIME_ID_OFF] << 21) |
(((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5) << 18) |
((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0x07) << 15) |
(buf[HI3110_FIFO_WOTIME_ID_OFF + 2] << 7) |
(buf[HI3110_FIFO_WOTIME_ID_OFF + 3] >> 1);
} else {
/* IDE is dominant (0), frame indicating standard 11-bit */
frame->can_id =
(buf[HI3110_FIFO_WOTIME_ID_OFF] << 3) |
((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5);
}
/* Data length */
frame->can_dlc = get_can_dlc(buf[HI3110_FIFO_WOTIME_DLC_OFF] & 0x0F);
if (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] & HI3110_FIFO_WOTIME_ID_RTR)
frame->can_id |= CAN_RTR_FLAG;
else
memcpy(frame->data, buf + HI3110_FIFO_WOTIME_DAT_OFF,
frame->can_dlc);
priv->net->stats.rx_packets++;
priv->net->stats.rx_bytes += frame->can_dlc;
can_led_event(priv->net, CAN_LED_EVENT_RX);
netif_rx_ni(skb);
}
static void hi3110_hw_sleep(struct spi_device *spi)
{
hi3110_write(spi, HI3110_WRITE_CTRL0, HI3110_CTRL0_SLEEP_MODE);
}
static netdev_tx_t hi3110_hard_start_xmit(struct sk_buff *skb,
struct net_device *net)
{
struct hi3110_priv *priv = netdev_priv(net);
struct spi_device *spi = priv->spi;
if (priv->tx_skb || priv->tx_len) {
dev_err(&spi->dev, "hard_xmit called while tx busy\n");
return NETDEV_TX_BUSY;
}
if (can_dropped_invalid_skb(net, skb))
return NETDEV_TX_OK;
netif_stop_queue(net);
priv->tx_skb = skb;
queue_work(priv->wq, &priv->tx_work);
return NETDEV_TX_OK;
}
static int hi3110_do_set_mode(struct net_device *net, enum can_mode mode)
{
struct hi3110_priv *priv = netdev_priv(net);
switch (mode) {
case CAN_MODE_START:
hi3110_clean(net);
/* We have to delay work since SPI I/O may sleep */
priv->can.state = CAN_STATE_ERROR_ACTIVE;
priv->restart_tx = 1;
if (priv->can.restart_ms == 0)
priv->after_suspend = HI3110_AFTER_SUSPEND_RESTART;
queue_work(priv->wq, &priv->restart_work);
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static int hi3110_get_berr_counter(const struct net_device *net,
struct can_berr_counter *bec)
{
struct hi3110_priv *priv = netdev_priv(net);
struct spi_device *spi = priv->spi;
mutex_lock(&priv->hi3110_lock);
bec->txerr = hi3110_read(spi, HI3110_READ_TEC);
bec->rxerr = hi3110_read(spi, HI3110_READ_REC);
mutex_unlock(&priv->hi3110_lock);
return 0;
}
static int hi3110_set_normal_mode(struct spi_device *spi)
{
struct hi3110_priv *priv = spi_get_drvdata(spi);
u8 reg = 0;
hi3110_write(spi, HI3110_WRITE_INTE, HI3110_INT_BUSERR |
HI3110_INT_RXFIFO | HI3110_INT_TXCPLT);
/* Enable TX */
hi3110_write(spi, HI3110_WRITE_CTRL1, HI3110_CTRL1_TXEN);
if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
reg = HI3110_CTRL0_LOOPBACK_MODE;
else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
reg = HI3110_CTRL0_MONITOR_MODE;
else
reg = HI3110_CTRL0_NORMAL_MODE;
hi3110_write(spi, HI3110_WRITE_CTRL0, reg);
/* Wait for the device to enter the mode */
mdelay(HI3110_OST_DELAY_MS);
reg = hi3110_read(spi, HI3110_READ_CTRL0);
if ((reg & HI3110_CTRL0_MODE_MASK) != reg)
return -EBUSY;
priv->can.state = CAN_STATE_ERROR_ACTIVE;
return 0;
}
static int hi3110_do_set_bittiming(struct net_device *net)
{
struct hi3110_priv *priv = netdev_priv(net);
struct can_bittiming *bt = &priv->can.bittiming;
struct spi_device *spi = priv->spi;
hi3110_write(spi, HI3110_WRITE_BTR0,
((bt->sjw - 1) << HI3110_BTR0_SJW_SHIFT) |
((bt->brp - 1) << HI3110_BTR0_BRP_SHIFT));
hi3110_write(spi, HI3110_WRITE_BTR1,
(priv->can.ctrlmode &
CAN_CTRLMODE_3_SAMPLES ?
HI3110_BTR1_SAMP_3PERBIT : HI3110_BTR1_SAMP_1PERBIT) |
((bt->phase_seg1 + bt->prop_seg - 1)
<< HI3110_BTR1_TSEG1_SHIFT) |
((bt->phase_seg2 - 1) << HI3110_BTR1_TSEG2_SHIFT));
dev_dbg(&spi->dev, "BT: 0x%02x 0x%02x\n",
hi3110_read(spi, HI3110_READ_BTR0),
hi3110_read(spi, HI3110_READ_BTR1));
return 0;
}
static int hi3110_setup(struct net_device *net)
{
hi3110_do_set_bittiming(net);
return 0;
}
static int hi3110_hw_reset(struct spi_device *spi)
{
u8 reg;
int ret;
/* Wait for oscillator startup timer after power up */
mdelay(HI3110_OST_DELAY_MS);
ret = hi3110_cmd(spi, HI3110_MASTER_RESET);
if (ret)
return ret;
/* Wait for oscillator startup timer after reset */
mdelay(HI3110_OST_DELAY_MS);
reg = hi3110_read(spi, HI3110_READ_CTRL0);
if ((reg & HI3110_CTRL0_MODE_MASK) != HI3110_CTRL0_INIT_MODE)
return -ENODEV;
/* As per the datasheet it appears the error flags are
* not cleared on reset. Explicitly clear them by performing a read
*/
hi3110_read(spi, HI3110_READ_ERR);
return 0;
}
static int hi3110_hw_probe(struct spi_device *spi)
{
u8 statf;
hi3110_hw_reset(spi);
/* Confirm correct operation by checking against reset values
* in datasheet
*/
statf = hi3110_read(spi, HI3110_READ_STATF);
dev_dbg(&spi->dev, "statf: %02X\n", statf);
if (statf != 0x82)
return -ENODEV;
return 0;
}
static int hi3110_power_enable(struct regulator *reg, int enable)
{
if (IS_ERR_OR_NULL(reg))
return 0;
if (enable)
return regulator_enable(reg);
else
return regulator_disable(reg);
}
static int hi3110_stop(struct net_device *net)
{
struct hi3110_priv *priv = netdev_priv(net);
struct spi_device *spi = priv->spi;
close_candev(net);
priv->force_quit = 1;
free_irq(spi->irq, priv);
destroy_workqueue(priv->wq);
priv->wq = NULL;
mutex_lock(&priv->hi3110_lock);
/* Disable transmit, interrupts and clear flags */
hi3110_write(spi, HI3110_WRITE_CTRL1, 0x0);
hi3110_write(spi, HI3110_WRITE_INTE, 0x0);
hi3110_read(spi, HI3110_READ_INTF);
hi3110_clean(net);
hi3110_hw_sleep(spi);
hi3110_power_enable(priv->transceiver, 0);
priv->can.state = CAN_STATE_STOPPED;
mutex_unlock(&priv->hi3110_lock);
can_led_event(net, CAN_LED_EVENT_STOP);
return 0;
}
static void hi3110_tx_work_handler(struct work_struct *ws)
{
struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
tx_work);
struct spi_device *spi = priv->spi;
struct net_device *net = priv->net;
struct can_frame *frame;
mutex_lock(&priv->hi3110_lock);
if (priv->tx_skb) {
if (priv->can.state == CAN_STATE_BUS_OFF) {
hi3110_clean(net);
} else {
frame = (struct can_frame *)priv->tx_skb->data;
hi3110_hw_tx(spi, frame);
priv->tx_len = 1 + frame->can_dlc;
can_put_echo_skb(priv->tx_skb, net, 0);
priv->tx_skb = NULL;
}
}
mutex_unlock(&priv->hi3110_lock);
}
static void hi3110_restart_work_handler(struct work_struct *ws)
{
struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
restart_work);
struct spi_device *spi = priv->spi;
struct net_device *net = priv->net;
mutex_lock(&priv->hi3110_lock);
if (priv->after_suspend) {
hi3110_hw_reset(spi);
hi3110_setup(net);
if (priv->after_suspend & HI3110_AFTER_SUSPEND_RESTART) {
hi3110_set_normal_mode(spi);
} else if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {
netif_device_attach(net);
hi3110_clean(net);
hi3110_set_normal_mode(spi);
netif_wake_queue(net);
} else {
hi3110_hw_sleep(spi);
}
priv->after_suspend = 0;
priv->force_quit = 0;
}
if (priv->restart_tx) {
priv->restart_tx = 0;
hi3110_hw_reset(spi);
hi3110_setup(net);
hi3110_clean(net);
hi3110_set_normal_mode(spi);
netif_wake_queue(net);
}
mutex_unlock(&priv->hi3110_lock);
}
static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
{
struct hi3110_priv *priv = dev_id;
struct spi_device *spi = priv->spi;
struct net_device *net = priv->net;
mutex_lock(&priv->hi3110_lock);
while (!priv->force_quit) {
enum can_state new_state;
u8 intf, eflag, statf;
while (!(HI3110_STAT_RXFMTY &
(statf = hi3110_read(spi, HI3110_READ_STATF)))) {
hi3110_hw_rx(spi);
}
intf = hi3110_read(spi, HI3110_READ_INTF);
eflag = hi3110_read(spi, HI3110_READ_ERR);
/* Update can state */
if (eflag & HI3110_ERR_BUSOFF)
new_state = CAN_STATE_BUS_OFF;
else if (eflag & HI3110_ERR_PASSIVE_MASK)
new_state = CAN_STATE_ERROR_PASSIVE;
else if (statf & HI3110_STAT_ERRW)
new_state = CAN_STATE_ERROR_WARNING;
else
new_state = CAN_STATE_ERROR_ACTIVE;
if (new_state != priv->can.state) {
struct can_frame *cf;
struct sk_buff *skb;
enum can_state rx_state, tx_state;
u8 rxerr, txerr;
skb = alloc_can_err_skb(net, &cf);
if (!skb)
break;
txerr = hi3110_read(spi, HI3110_READ_TEC);
rxerr = hi3110_read(spi, HI3110_READ_REC);
cf->data[6] = txerr;
cf->data[7] = rxerr;
tx_state = txerr >= rxerr ? new_state : 0;
rx_state = txerr <= rxerr ? new_state : 0;
can_change_state(net, cf, tx_state, rx_state);
netif_rx_ni(skb);
if (new_state == CAN_STATE_BUS_OFF) {
can_bus_off(net);
if (priv->can.restart_ms == 0) {
priv->force_quit = 1;
hi3110_hw_sleep(spi);
break;
}
}
}
/* Update bus errors */
if ((intf & HI3110_INT_BUSERR) &&
(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
struct can_frame *cf;
struct sk_buff *skb;
/* Check for protocol errors */
if (eflag & HI3110_ERR_PROTOCOL_MASK) {
skb = alloc_can_err_skb(net, &cf);
if (!skb)
break;
cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
priv->can.can_stats.bus_error++;
priv->net->stats.rx_errors++;
if (eflag & HI3110_ERR_BITERR)
cf->data[2] |= CAN_ERR_PROT_BIT;
else if (eflag & HI3110_ERR_FRMERR)
cf->data[2] |= CAN_ERR_PROT_FORM;
else if (eflag & HI3110_ERR_STUFERR)
cf->data[2] |= CAN_ERR_PROT_STUFF;
else if (eflag & HI3110_ERR_CRCERR)
cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
else if (eflag & HI3110_ERR_ACKERR)
cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
cf->data[6] = hi3110_read(spi, HI3110_READ_TEC);
cf->data[7] = hi3110_read(spi, HI3110_READ_REC);
netdev_dbg(priv->net, "Bus Error\n");
netif_rx_ni(skb);
}
}
if (priv->tx_len && statf & HI3110_STAT_TXMTY) {
net->stats.tx_packets++;
net->stats.tx_bytes += priv->tx_len - 1;
can_led_event(net, CAN_LED_EVENT_TX);
if (priv->tx_len) {
can_get_echo_skb(net, 0);
priv->tx_len = 0;
}
netif_wake_queue(net);
}
if (intf == 0)
break;
}
mutex_unlock(&priv->hi3110_lock);
return IRQ_HANDLED;
}
static int hi3110_open(struct net_device *net)
{
struct hi3110_priv *priv = netdev_priv(net);
struct spi_device *spi = priv->spi;
unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_RISING;
int ret;
ret = open_candev(net);
if (ret)
return ret;
mutex_lock(&priv->hi3110_lock);
hi3110_power_enable(priv->transceiver, 1);
priv->force_quit = 0;
priv->tx_skb = NULL;
priv->tx_len = 0;
ret = request_threaded_irq(spi->irq, NULL, hi3110_can_ist,
flags, DEVICE_NAME, priv);
if (ret) {
dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
goto out_close;
}
priv->wq = alloc_workqueue("hi3110_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
0);
if (!priv->wq) {
ret = -ENOMEM;
goto out_free_irq;
}
INIT_WORK(&priv->tx_work, hi3110_tx_work_handler);
INIT_WORK(&priv->restart_work, hi3110_restart_work_handler);
ret = hi3110_hw_reset(spi);
if (ret)
goto out_free_wq;
ret = hi3110_setup(net);
if (ret)
goto out_free_wq;
ret = hi3110_set_normal_mode(spi);
if (ret)
goto out_free_wq;
can_led_event(net, CAN_LED_EVENT_OPEN);
netif_wake_queue(net);
mutex_unlock(&priv->hi3110_lock);
return 0;
out_free_wq:
destroy_workqueue(priv->wq);
out_free_irq:
free_irq(spi->irq, priv);
hi3110_hw_sleep(spi);
out_close:
hi3110_power_enable(priv->transceiver, 0);
close_candev(net);
mutex_unlock(&priv->hi3110_lock);
return ret;
}
static const struct net_device_ops hi3110_netdev_ops = {
.ndo_open = hi3110_open,
.ndo_stop = hi3110_stop,
.ndo_start_xmit = hi3110_hard_start_xmit,
};
static const struct of_device_id hi3110_of_match[] = {
{
.compatible = "holt,hi3110",
.data = (void *)CAN_HI3110_HI3110,
},
{ }
};
MODULE_DEVICE_TABLE(of, hi3110_of_match);
static const struct spi_device_id hi3110_id_table[] = {
{
.name = "hi3110",
.driver_data = (kernel_ulong_t)CAN_HI3110_HI3110,
},
{ }
};
MODULE_DEVICE_TABLE(spi, hi3110_id_table);
static int hi3110_can_probe(struct spi_device *spi)
{
const struct of_device_id *of_id = of_match_device(hi3110_of_match,
&spi->dev);
struct net_device *net;
struct hi3110_priv *priv;
struct clk *clk;
int freq, ret;
clk = devm_clk_get(&spi->dev, NULL);
if (IS_ERR(clk)) {
dev_err(&spi->dev, "no CAN clock source defined\n");
return PTR_ERR(clk);
}
freq = clk_get_rate(clk);
/* Sanity check */
if (freq > 40000000)
return -ERANGE;
/* Allocate can/net device */
net = alloc_candev(sizeof(struct hi3110_priv), HI3110_TX_ECHO_SKB_MAX);
if (!net)
return -ENOMEM;
if (!IS_ERR(clk)) {
ret = clk_prepare_enable(clk);
if (ret)
goto out_free;
}
net->netdev_ops = &hi3110_netdev_ops;
net->flags |= IFF_ECHO;
priv = netdev_priv(net);
priv->can.bittiming_const = &hi3110_bittiming_const;
priv->can.do_set_mode = hi3110_do_set_mode;
priv->can.do_get_berr_counter = hi3110_get_berr_counter;
priv->can.clock.freq = freq / 2;
priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
CAN_CTRLMODE_LOOPBACK |
CAN_CTRLMODE_LISTENONLY |
CAN_CTRLMODE_BERR_REPORTING;
if (of_id)
priv->model = (enum hi3110_model)of_id->data;
else
priv->model = spi_get_device_id(spi)->driver_data;
priv->net = net;
priv->clk = clk;
spi_set_drvdata(spi, priv);
/* Configure the SPI bus */
spi->bits_per_word = 8;
ret = spi_setup(spi);
if (ret)
goto out_clk;
priv->power = devm_regulator_get_optional(&spi->dev, "vdd");
priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
(PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
ret = -EPROBE_DEFER;
goto out_clk;
}
ret = hi3110_power_enable(priv->power, 1);
if (ret)
goto out_clk;
priv->spi = spi;
mutex_init(&priv->hi3110_lock);
/* If requested, allocate DMA buffers */
if (hi3110_enable_dma) {
spi->dev.coherent_dma_mask = ~0;
/* Minimum coherent DMA allocation is PAGE_SIZE, so allocate
* that much and share it between Tx and Rx DMA buffers.
*/
priv->spi_tx_buf = dmam_alloc_coherent(&spi->dev,
PAGE_SIZE,
&priv->spi_tx_dma,
GFP_DMA);
if (priv->spi_tx_buf) {
priv->spi_rx_buf = (priv->spi_tx_buf + (PAGE_SIZE / 2));
priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma +
(PAGE_SIZE / 2));
} else {
/* Fall back to non-DMA */
hi3110_enable_dma = 0;
}
}
/* Allocate non-DMA buffers */
if (!hi3110_enable_dma) {
priv->spi_tx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,
GFP_KERNEL);
if (!priv->spi_tx_buf) {
ret = -ENOMEM;
goto error_probe;
}
priv->spi_rx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,
GFP_KERNEL);
if (!priv->spi_rx_buf) {
ret = -ENOMEM;
goto error_probe;
}
}
SET_NETDEV_DEV(net, &spi->dev);
ret = hi3110_hw_probe(spi);
if (ret) {
if (ret == -ENODEV)
dev_err(&spi->dev, "Cannot initialize %x. Wrong wiring?\n",
priv->model);
goto error_probe;
}
hi3110_hw_sleep(spi);
ret = register_candev(net);
if (ret)
goto error_probe;
devm_can_led_init(net);
netdev_info(net, "%x successfully initialized.\n", priv->model);
return 0;
error_probe:
hi3110_power_enable(priv->power, 0);
out_clk:
if (!IS_ERR(clk))
clk_disable_unprepare(clk);
out_free:
free_candev(net);
dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);
return ret;
}
static int hi3110_can_remove(struct spi_device *spi)
{
struct hi3110_priv *priv = spi_get_drvdata(spi);
struct net_device *net = priv->net;
unregister_candev(net);
hi3110_power_enable(priv->power, 0);
if (!IS_ERR(priv->clk))
clk_disable_unprepare(priv->clk);
free_candev(net);
return 0;
}
static int __maybe_unused hi3110_can_suspend(struct device *dev)
{
struct spi_device *spi = to_spi_device(dev);
struct hi3110_priv *priv = spi_get_drvdata(spi);
struct net_device *net = priv->net;
priv->force_quit = 1;
disable_irq(spi->irq);
/* Note: at this point neither IST nor workqueues are running.
* open/stop cannot be called anyway so locking is not needed
*/
if (netif_running(net)) {
netif_device_detach(net);
hi3110_hw_sleep(spi);
hi3110_power_enable(priv->transceiver, 0);
priv->after_suspend = HI3110_AFTER_SUSPEND_UP;
} else {
priv->after_suspend = HI3110_AFTER_SUSPEND_DOWN;
}
if (!IS_ERR_OR_NULL(priv->power)) {
regulator_disable(priv->power);
priv->after_suspend |= HI3110_AFTER_SUSPEND_POWER;
}
return 0;
}
static int __maybe_unused hi3110_can_resume(struct device *dev)
{
struct spi_device *spi = to_spi_device(dev);
struct hi3110_priv *priv = spi_get_drvdata(spi);
if (priv->after_suspend & HI3110_AFTER_SUSPEND_POWER)
hi3110_power_enable(priv->power, 1);
if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {
hi3110_power_enable(priv->transceiver, 1);
queue_work(priv->wq, &priv->restart_work);
} else {
priv->after_suspend = 0;
}
priv->force_quit = 0;
enable_irq(spi->irq);
return 0;
}
static SIMPLE_DEV_PM_OPS(hi3110_can_pm_ops, hi3110_can_suspend, hi3110_can_resume);
static struct spi_driver hi3110_can_driver = {
.driver = {
.name = DEVICE_NAME,
.of_match_table = hi3110_of_match,
.pm = &hi3110_can_pm_ops,
},
.id_table = hi3110_id_table,
.probe = hi3110_can_probe,
.remove = hi3110_can_remove,
};
module_spi_driver(hi3110_can_driver);
MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");
MODULE_AUTHOR("Casey Fitzpatrick <casey.fitzpatrick@timesys.com>");
MODULE_DESCRIPTION("Holt HI-3110 CAN driver");
MODULE_LICENSE("GPL v2");