/*
* TI HECC (CAN) device driver
*
* This driver supports TI's HECC (High End CAN Controller module) and the
* specs for the same is available at <http://www.ti.com>
*
* Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed as is WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
/*
* Your platform definitions should specify module ram offsets and interrupt
* number to use as follows:
*
* static struct ti_hecc_platform_data am3517_evm_hecc_pdata = {
* .scc_hecc_offset = 0,
* .scc_ram_offset = 0x3000,
* .hecc_ram_offset = 0x3000,
* .mbx_offset = 0x2000,
* .int_line = 0,
* .revision = 1,
* .transceiver_switch = hecc_phy_control,
* };
*
* Please see include/linux/can/platform/ti_hecc.h for description of
* above fields.
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/can/led.h>
#include <linux/can/platform/ti_hecc.h>
#define DRV_NAME "ti_hecc"
#define HECC_MODULE_VERSION "0.7"
MODULE_VERSION(HECC_MODULE_VERSION);
#define DRV_DESC "TI High End CAN Controller Driver " HECC_MODULE_VERSION
/* TX / RX Mailbox Configuration */
#define HECC_MAX_MAILBOXES 32 /* hardware mailboxes - do not change */
#define MAX_TX_PRIO 0x3F /* hardware value - do not change */
/*
* Important Note: TX mailbox configuration
* TX mailboxes should be restricted to the number of SKB buffers to avoid
* maintaining SKB buffers separately. TX mailboxes should be a power of 2
* for the mailbox logic to work. Top mailbox numbers are reserved for RX
* and lower mailboxes for TX.
*
* HECC_MAX_TX_MBOX HECC_MB_TX_SHIFT
* 4 (default) 2
* 8 3
* 16 4
*/
#define HECC_MB_TX_SHIFT 2 /* as per table above */
#define HECC_MAX_TX_MBOX BIT(HECC_MB_TX_SHIFT)
#define HECC_TX_PRIO_SHIFT (HECC_MB_TX_SHIFT)
#define HECC_TX_PRIO_MASK (MAX_TX_PRIO << HECC_MB_TX_SHIFT)
#define HECC_TX_MB_MASK (HECC_MAX_TX_MBOX - 1)
#define HECC_TX_MASK ((HECC_MAX_TX_MBOX - 1) | HECC_TX_PRIO_MASK)
#define HECC_TX_MBOX_MASK (~(BIT(HECC_MAX_TX_MBOX) - 1))
#define HECC_DEF_NAPI_WEIGHT HECC_MAX_RX_MBOX
/*
* Important Note: RX mailbox configuration
* RX mailboxes are further logically split into two - main and buffer
* mailboxes. The goal is to get all packets into main mailboxes as
* driven by mailbox number and receive priority (higher to lower) and
* buffer mailboxes are used to receive pkts while main mailboxes are being
* processed. This ensures in-order packet reception.
*
* Here are the recommended values for buffer mailbox. Note that RX mailboxes
* start after TX mailboxes:
*
* HECC_MAX_RX_MBOX HECC_RX_BUFFER_MBOX No of buffer mailboxes
* 28 12 8
* 16 20 4
*/
#define HECC_MAX_RX_MBOX (HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX)
#define HECC_RX_BUFFER_MBOX 12 /* as per table above */
#define HECC_RX_FIRST_MBOX (HECC_MAX_MAILBOXES - 1)
#define HECC_RX_HIGH_MBOX_MASK (~(BIT(HECC_RX_BUFFER_MBOX) - 1))
/* TI HECC module registers */
#define HECC_CANME 0x0 /* Mailbox enable */
#define HECC_CANMD 0x4 /* Mailbox direction */
#define HECC_CANTRS 0x8 /* Transmit request set */
#define HECC_CANTRR 0xC /* Transmit request */
#define HECC_CANTA 0x10 /* Transmission acknowledge */
#define HECC_CANAA 0x14 /* Abort acknowledge */
#define HECC_CANRMP 0x18 /* Receive message pending */
#define HECC_CANRML 0x1C /* Remote message lost */
#define HECC_CANRFP 0x20 /* Remote frame pending */
#define HECC_CANGAM 0x24 /* SECC only:Global acceptance mask */
#define HECC_CANMC 0x28 /* Master control */
#define HECC_CANBTC 0x2C /* Bit timing configuration */
#define HECC_CANES 0x30 /* Error and status */
#define HECC_CANTEC 0x34 /* Transmit error counter */
#define HECC_CANREC 0x38 /* Receive error counter */
#define HECC_CANGIF0 0x3C /* Global interrupt flag 0 */
#define HECC_CANGIM 0x40 /* Global interrupt mask */
#define HECC_CANGIF1 0x44 /* Global interrupt flag 1 */
#define HECC_CANMIM 0x48 /* Mailbox interrupt mask */
#define HECC_CANMIL 0x4C /* Mailbox interrupt level */
#define HECC_CANOPC 0x50 /* Overwrite protection control */
#define HECC_CANTIOC 0x54 /* Transmit I/O control */
#define HECC_CANRIOC 0x58 /* Receive I/O control */
#define HECC_CANLNT 0x5C /* HECC only: Local network time */
#define HECC_CANTOC 0x60 /* HECC only: Time-out control */
#define HECC_CANTOS 0x64 /* HECC only: Time-out status */
#define HECC_CANTIOCE 0x68 /* SCC only:Enhanced TX I/O control */
#define HECC_CANRIOCE 0x6C /* SCC only:Enhanced RX I/O control */
/* Mailbox registers */
#define HECC_CANMID 0x0
#define HECC_CANMCF 0x4
#define HECC_CANMDL 0x8
#define HECC_CANMDH 0xC
#define HECC_SET_REG 0xFFFFFFFF
#define HECC_CANID_MASK 0x3FF /* 18 bits mask for extended id's */
#define HECC_CCE_WAIT_COUNT 100 /* Wait for ~1 sec for CCE bit */
#define HECC_CANMC_SCM BIT(13) /* SCC compat mode */
#define HECC_CANMC_CCR BIT(12) /* Change config request */
#define HECC_CANMC_PDR BIT(11) /* Local Power down - for sleep mode */
#define HECC_CANMC_ABO BIT(7) /* Auto Bus On */
#define HECC_CANMC_STM BIT(6) /* Self test mode - loopback */
#define HECC_CANMC_SRES BIT(5) /* Software reset */
#define HECC_CANTIOC_EN BIT(3) /* Enable CAN TX I/O pin */
#define HECC_CANRIOC_EN BIT(3) /* Enable CAN RX I/O pin */
#define HECC_CANMID_IDE BIT(31) /* Extended frame format */
#define HECC_CANMID_AME BIT(30) /* Acceptance mask enable */
#define HECC_CANMID_AAM BIT(29) /* Auto answer mode */
#define HECC_CANES_FE BIT(24) /* form error */
#define HECC_CANES_BE BIT(23) /* bit error */
#define HECC_CANES_SA1 BIT(22) /* stuck at dominant error */
#define HECC_CANES_CRCE BIT(21) /* CRC error */
#define HECC_CANES_SE BIT(20) /* stuff bit error */
#define HECC_CANES_ACKE BIT(19) /* ack error */
#define HECC_CANES_BO BIT(18) /* Bus off status */
#define HECC_CANES_EP BIT(17) /* Error passive status */
#define HECC_CANES_EW BIT(16) /* Error warning status */
#define HECC_CANES_SMA BIT(5) /* suspend mode ack */
#define HECC_CANES_CCE BIT(4) /* Change config enabled */
#define HECC_CANES_PDA BIT(3) /* Power down mode ack */
#define HECC_CANBTC_SAM BIT(7) /* sample points */
#define HECC_BUS_ERROR (HECC_CANES_FE | HECC_CANES_BE |\
HECC_CANES_CRCE | HECC_CANES_SE |\
HECC_CANES_ACKE)
#define HECC_CANMCF_RTR BIT(4) /* Remote transmit request */
#define HECC_CANGIF_MAIF BIT(17) /* Message alarm interrupt */
#define HECC_CANGIF_TCOIF BIT(16) /* Timer counter overflow int */
#define HECC_CANGIF_GMIF BIT(15) /* Global mailbox interrupt */
#define HECC_CANGIF_AAIF BIT(14) /* Abort ack interrupt */
#define HECC_CANGIF_WDIF BIT(13) /* Write denied interrupt */
#define HECC_CANGIF_WUIF BIT(12) /* Wake up interrupt */
#define HECC_CANGIF_RMLIF BIT(11) /* Receive message lost interrupt */
#define HECC_CANGIF_BOIF BIT(10) /* Bus off interrupt */
#define HECC_CANGIF_EPIF BIT(9) /* Error passive interrupt */
#define HECC_CANGIF_WLIF BIT(8) /* Warning level interrupt */
#define HECC_CANGIF_MBOX_MASK 0x1F /* Mailbox number mask */
#define HECC_CANGIM_I1EN BIT(1) /* Int line 1 enable */
#define HECC_CANGIM_I0EN BIT(0) /* Int line 0 enable */
#define HECC_CANGIM_DEF_MASK 0x700 /* only busoff/warning/passive */
#define HECC_CANGIM_SIL BIT(2) /* system interrupts to int line 1 */
/* CAN Bittiming constants as per HECC specs */
static const struct can_bittiming_const ti_hecc_bittiming_const = {
.name = DRV_NAME,
.tseg1_min = 1,
.tseg1_max = 16,
.tseg2_min = 1,
.tseg2_max = 8,
.sjw_max = 4,
.brp_min = 1,
.brp_max = 256,
.brp_inc = 1,
};
struct ti_hecc_priv {
struct can_priv can; /* MUST be first member/field */
struct napi_struct napi;
struct net_device *ndev;
struct clk *clk;
void __iomem *base;
u32 scc_ram_offset;
u32 hecc_ram_offset;
u32 mbx_offset;
u32 int_line;
spinlock_t mbx_lock; /* CANME register needs protection */
u32 tx_head;
u32 tx_tail;
u32 rx_next;
void (*transceiver_switch)(int);
};
static inline int get_tx_head_mb(struct ti_hecc_priv *priv)
{
return priv->tx_head & HECC_TX_MB_MASK;
}
static inline int get_tx_tail_mb(struct ti_hecc_priv *priv)
{
return priv->tx_tail & HECC_TX_MB_MASK;
}
static inline int get_tx_head_prio(struct ti_hecc_priv *priv)
{
return (priv->tx_head >> HECC_TX_PRIO_SHIFT) & MAX_TX_PRIO;
}
static inline void hecc_write_lam(struct ti_hecc_priv *priv, u32 mbxno, u32 val)
{
__raw_writel(val, priv->base + priv->hecc_ram_offset + mbxno * 4);
}
static inline void hecc_write_mbx(struct ti_hecc_priv *priv, u32 mbxno,
u32 reg, u32 val)
{
__raw_writel(val, priv->base + priv->mbx_offset + mbxno * 0x10 +
reg);
}
static inline u32 hecc_read_mbx(struct ti_hecc_priv *priv, u32 mbxno, u32 reg)
{
return __raw_readl(priv->base + priv->mbx_offset + mbxno * 0x10 +
reg);
}
static inline void hecc_write(struct ti_hecc_priv *priv, u32 reg, u32 val)
{
__raw_writel(val, priv->base + reg);
}
static inline u32 hecc_read(struct ti_hecc_priv *priv, int reg)
{
return __raw_readl(priv->base + reg);
}
static inline void hecc_set_bit(struct ti_hecc_priv *priv, int reg,
u32 bit_mask)
{
hecc_write(priv, reg, hecc_read(priv, reg) | bit_mask);
}
static inline void hecc_clear_bit(struct ti_hecc_priv *priv, int reg,
u32 bit_mask)
{
hecc_write(priv, reg, hecc_read(priv, reg) & ~bit_mask);
}
static inline u32 hecc_get_bit(struct ti_hecc_priv *priv, int reg, u32 bit_mask)
{
return (hecc_read(priv, reg) & bit_mask) ? 1 : 0;
}
static int ti_hecc_set_btc(struct ti_hecc_priv *priv)
{
struct can_bittiming *bit_timing = &priv->can.bittiming;
u32 can_btc;
can_btc = (bit_timing->phase_seg2 - 1) & 0x7;
can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1)
& 0xF) << 3;
if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) {
if (bit_timing->brp > 4)
can_btc |= HECC_CANBTC_SAM;
else
netdev_warn(priv->ndev, "WARN: Triple"
"sampling not set due to h/w limitations");
}
can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8;
can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16;
/* ERM being set to 0 by default meaning resync at falling edge */
hecc_write(priv, HECC_CANBTC, can_btc);
netdev_info(priv->ndev, "setting CANBTC=%#x\n", can_btc);
return 0;
}
static void ti_hecc_transceiver_switch(const struct ti_hecc_priv *priv,
int on)
{
if (priv->transceiver_switch)
priv->transceiver_switch(on);
}
static void ti_hecc_reset(struct net_device *ndev)
{
u32 cnt;
struct ti_hecc_priv *priv = netdev_priv(ndev);
netdev_dbg(ndev, "resetting hecc ...\n");
hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES);
/* Set change control request and wait till enabled */
hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
/*
* INFO: It has been observed that at times CCE bit may not be
* set and hw seems to be ok even if this bit is not set so
* timing out with a timing of 1ms to respect the specs
*/
cnt = HECC_CCE_WAIT_COUNT;
while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
--cnt;
udelay(10);
}
/*
* Note: On HECC, BTC can be programmed only in initialization mode, so
* it is expected that the can bittiming parameters are set via ip
* utility before the device is opened
*/
ti_hecc_set_btc(priv);
/* Clear CCR (and CANMC register) and wait for CCE = 0 enable */
hecc_write(priv, HECC_CANMC, 0);
/*
* INFO: CAN net stack handles bus off and hence disabling auto-bus-on
* hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO);
*/
/*
* INFO: It has been observed that at times CCE bit may not be
* set and hw seems to be ok even if this bit is not set so
*/
cnt = HECC_CCE_WAIT_COUNT;
while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
--cnt;
udelay(10);
}
/* Enable TX and RX I/O Control pins */
hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN);
hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN);
/* Clear registers for clean operation */
hecc_write(priv, HECC_CANTA, HECC_SET_REG);
hecc_write(priv, HECC_CANRMP, HECC_SET_REG);
hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
hecc_write(priv, HECC_CANME, 0);
hecc_write(priv, HECC_CANMD, 0);
/* SCC compat mode NOT supported (and not needed too) */
hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM);
}
static void ti_hecc_start(struct net_device *ndev)
{
struct ti_hecc_priv *priv = netdev_priv(ndev);
u32 cnt, mbxno, mbx_mask;
/* put HECC in initialization mode and set btc */
ti_hecc_reset(ndev);
priv->tx_head = priv->tx_tail = HECC_TX_MASK;
priv->rx_next = HECC_RX_FIRST_MBOX;
/* Enable local and global acceptance mask registers */
hecc_write(priv, HECC_CANGAM, HECC_SET_REG);
/* Prepare configured mailboxes to receive messages */
for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) {
mbxno = HECC_MAX_MAILBOXES - 1 - cnt;
mbx_mask = BIT(mbxno);
hecc_clear_bit(priv, HECC_CANME, mbx_mask);
hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME);
hecc_write_lam(priv, mbxno, HECC_SET_REG);
hecc_set_bit(priv, HECC_CANMD, mbx_mask);
hecc_set_bit(priv, HECC_CANME, mbx_mask);
hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
}
/* Prevent message over-write & Enable interrupts */
hecc_write(priv, HECC_CANOPC, HECC_SET_REG);
if (priv->int_line) {
hecc_write(priv, HECC_CANMIL, HECC_SET_REG);
hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK |
HECC_CANGIM_I1EN | HECC_CANGIM_SIL);
} else {
hecc_write(priv, HECC_CANMIL, 0);
hecc_write(priv, HECC_CANGIM,
HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN);
}
priv->can.state = CAN_STATE_ERROR_ACTIVE;
}
static void ti_hecc_stop(struct net_device *ndev)
{
struct ti_hecc_priv *priv = netdev_priv(ndev);
/* Disable interrupts and disable mailboxes */
hecc_write(priv, HECC_CANGIM, 0);
hecc_write(priv, HECC_CANMIM, 0);
hecc_write(priv, HECC_CANME, 0);
priv->can.state = CAN_STATE_STOPPED;
}
static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode)
{
int ret = 0;
switch (mode) {
case CAN_MODE_START:
ti_hecc_start(ndev);
netif_wake_queue(ndev);
break;
default:
ret = -EOPNOTSUPP;
break;
}
return ret;
}
static int ti_hecc_get_berr_counter(const struct net_device *ndev,
struct can_berr_counter *bec)
{
struct ti_hecc_priv *priv = netdev_priv(ndev);
bec->txerr = hecc_read(priv, HECC_CANTEC);
bec->rxerr = hecc_read(priv, HECC_CANREC);
return 0;
}
/*
* ti_hecc_xmit: HECC Transmit
*
* The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the
* priority of the mailbox for tranmission is dependent upon priority setting
* field in mailbox registers. The mailbox with highest value in priority field
* is transmitted first. Only when two mailboxes have the same value in
* priority field the highest numbered mailbox is transmitted first.
*
* To utilize the HECC priority feature as described above we start with the
* highest numbered mailbox with highest priority level and move on to the next
* mailbox with the same priority level and so on. Once we loop through all the
* transmit mailboxes we choose the next priority level (lower) and so on
* until we reach the lowest priority level on the lowest numbered mailbox
* when we stop transmission until all mailboxes are transmitted and then
* restart at highest numbered mailbox with highest priority.
*
* Two counters (head and tail) are used to track the next mailbox to transmit
* and to track the echo buffer for already transmitted mailbox. The queue
* is stopped when all the mailboxes are busy or when there is a priority
* value roll-over happens.
*/
static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
{
struct ti_hecc_priv *priv = netdev_priv(ndev);
struct can_frame *cf = (struct can_frame *)skb->data;
u32 mbxno, mbx_mask, data;
unsigned long flags;
if (can_dropped_invalid_skb(ndev, skb))
return NETDEV_TX_OK;
mbxno = get_tx_head_mb(priv);
mbx_mask = BIT(mbxno);
spin_lock_irqsave(&priv->mbx_lock, flags);
if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) {
spin_unlock_irqrestore(&priv->mbx_lock, flags);
netif_stop_queue(ndev);
netdev_err(priv->ndev,
"BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n",
priv->tx_head, priv->tx_tail);
return NETDEV_TX_BUSY;
}
spin_unlock_irqrestore(&priv->mbx_lock, flags);
/* Prepare mailbox for transmission */
data = cf->can_dlc | (get_tx_head_prio(priv) << 8);
if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */
data |= HECC_CANMCF_RTR;
hecc_write_mbx(priv, mbxno, HECC_CANMCF, data);
if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE;
else /* Standard frame format */
data = (cf->can_id & CAN_SFF_MASK) << 18;
hecc_write_mbx(priv, mbxno, HECC_CANMID, data);
hecc_write_mbx(priv, mbxno, HECC_CANMDL,
be32_to_cpu(*(u32 *)(cf->data)));
if (cf->can_dlc > 4)
hecc_write_mbx(priv, mbxno, HECC_CANMDH,
be32_to_cpu(*(u32 *)(cf->data + 4)));
else
*(u32 *)(cf->data + 4) = 0;
can_put_echo_skb(skb, ndev, mbxno);
spin_lock_irqsave(&priv->mbx_lock, flags);
--priv->tx_head;
if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) ||
(priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) {
netif_stop_queue(ndev);
}
hecc_set_bit(priv, HECC_CANME, mbx_mask);
spin_unlock_irqrestore(&priv->mbx_lock, flags);
hecc_clear_bit(priv, HECC_CANMD, mbx_mask);
hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
hecc_write(priv, HECC_CANTRS, mbx_mask);
return NETDEV_TX_OK;
}
static int ti_hecc_rx_pkt(struct ti_hecc_priv *priv, int mbxno)
{
struct net_device_stats *stats = &priv->ndev->stats;
struct can_frame *cf;
struct sk_buff *skb;
u32 data, mbx_mask;
unsigned long flags;
skb = alloc_can_skb(priv->ndev, &cf);
if (!skb) {
if (printk_ratelimit())
netdev_err(priv->ndev,
"ti_hecc_rx_pkt: alloc_can_skb() failed\n");
return -ENOMEM;
}
mbx_mask = BIT(mbxno);
data = hecc_read_mbx(priv, mbxno, HECC_CANMID);
if (data & HECC_CANMID_IDE)
cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
else
cf->can_id = (data >> 18) & CAN_SFF_MASK;
data = hecc_read_mbx(priv, mbxno, HECC_CANMCF);
if (data & HECC_CANMCF_RTR)
cf->can_id |= CAN_RTR_FLAG;
cf->can_dlc = get_can_dlc(data & 0xF);
data = hecc_read_mbx(priv, mbxno, HECC_CANMDL);
*(u32 *)(cf->data) = cpu_to_be32(data);
if (cf->can_dlc > 4) {
data = hecc_read_mbx(priv, mbxno, HECC_CANMDH);
*(u32 *)(cf->data + 4) = cpu_to_be32(data);
} else {
*(u32 *)(cf->data + 4) = 0;
}
spin_lock_irqsave(&priv->mbx_lock, flags);
hecc_clear_bit(priv, HECC_CANME, mbx_mask);
hecc_write(priv, HECC_CANRMP, mbx_mask);
/* enable mailbox only if it is part of rx buffer mailboxes */
if (priv->rx_next < HECC_RX_BUFFER_MBOX)
hecc_set_bit(priv, HECC_CANME, mbx_mask);
spin_unlock_irqrestore(&priv->mbx_lock, flags);
stats->rx_bytes += cf->can_dlc;
can_led_event(priv->ndev, CAN_LED_EVENT_RX);
netif_receive_skb(skb);
stats->rx_packets++;
return 0;
}
/*
* ti_hecc_rx_poll - HECC receive pkts
*
* The receive mailboxes start from highest numbered mailbox till last xmit
* mailbox. On CAN frame reception the hardware places the data into highest
* numbered mailbox that matches the CAN ID filter. Since all receive mailboxes
* have same filtering (ALL CAN frames) packets will arrive in the highest
* available RX mailbox and we need to ensure in-order packet reception.
*
* To ensure the packets are received in the right order we logically divide
* the RX mailboxes into main and buffer mailboxes. Packets are received as per
* mailbox priotity (higher to lower) in the main bank and once it is full we
* disable further reception into main mailboxes. While the main mailboxes are
* processed in NAPI, further packets are received in buffer mailboxes.
*
* We maintain a RX next mailbox counter to process packets and once all main
* mailboxe packets are passed to the upper stack we enable all of them but
* continue to process packets received in buffer mailboxes. With each packet
* received from buffer mailbox we enable it immediately so as to handle the
* overflow from higher mailboxes.
*/
static int ti_hecc_rx_poll(struct napi_struct *napi, int quota)
{
struct net_device *ndev = napi->dev;
struct ti_hecc_priv *priv = netdev_priv(ndev);
u32 num_pkts = 0;
u32 mbx_mask;
unsigned long pending_pkts, flags;
if (!netif_running(ndev))
return 0;
while ((pending_pkts = hecc_read(priv, HECC_CANRMP)) &&
num_pkts < quota) {
mbx_mask = BIT(priv->rx_next); /* next rx mailbox to process */
if (mbx_mask & pending_pkts) {
if (ti_hecc_rx_pkt(priv, priv->rx_next) < 0)
return num_pkts;
++num_pkts;
} else if (priv->rx_next > HECC_RX_BUFFER_MBOX) {
break; /* pkt not received yet */
}
--priv->rx_next;
if (priv->rx_next == HECC_RX_BUFFER_MBOX) {
/* enable high bank mailboxes */
spin_lock_irqsave(&priv->mbx_lock, flags);
mbx_mask = hecc_read(priv, HECC_CANME);
mbx_mask |= HECC_RX_HIGH_MBOX_MASK;
hecc_write(priv, HECC_CANME, mbx_mask);
spin_unlock_irqrestore(&priv->mbx_lock, flags);
} else if (priv->rx_next == HECC_MAX_TX_MBOX - 1) {
priv->rx_next = HECC_RX_FIRST_MBOX;
break;
}
}
/* Enable packet interrupt if all pkts are handled */
if (hecc_read(priv, HECC_CANRMP) == 0) {
napi_complete(napi);
/* Re-enable RX mailbox interrupts */
mbx_mask = hecc_read(priv, HECC_CANMIM);
mbx_mask |= HECC_TX_MBOX_MASK;
hecc_write(priv, HECC_CANMIM, mbx_mask);
}
return num_pkts;
}
static int ti_hecc_error(struct net_device *ndev, int int_status,
int err_status)
{
struct ti_hecc_priv *priv = netdev_priv(ndev);
struct net_device_stats *stats = &ndev->stats;
struct can_frame *cf;
struct sk_buff *skb;
/* propagate the error condition to the can stack */
skb = alloc_can_err_skb(ndev, &cf);
if (!skb) {
if (printk_ratelimit())
netdev_err(priv->ndev,
"ti_hecc_error: alloc_can_err_skb() failed\n");
return -ENOMEM;
}
if (int_status & HECC_CANGIF_WLIF) { /* warning level int */
if ((int_status & HECC_CANGIF_BOIF) == 0) {
priv->can.state = CAN_STATE_ERROR_WARNING;
++priv->can.can_stats.error_warning;
cf->can_id |= CAN_ERR_CRTL;
if (hecc_read(priv, HECC_CANTEC) > 96)
cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
if (hecc_read(priv, HECC_CANREC) > 96)
cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
}
hecc_set_bit(priv, HECC_CANES, HECC_CANES_EW);
netdev_dbg(priv->ndev, "Error Warning interrupt\n");
hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
}
if (int_status & HECC_CANGIF_EPIF) { /* error passive int */
if ((int_status & HECC_CANGIF_BOIF) == 0) {
priv->can.state = CAN_STATE_ERROR_PASSIVE;
++priv->can.can_stats.error_passive;
cf->can_id |= CAN_ERR_CRTL;
if (hecc_read(priv, HECC_CANTEC) > 127)
cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
if (hecc_read(priv, HECC_CANREC) > 127)
cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
}
hecc_set_bit(priv, HECC_CANES, HECC_CANES_EP);
netdev_dbg(priv->ndev, "Error passive interrupt\n");
hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
}
/*
* Need to check busoff condition in error status register too to
* ensure warning interrupts don't hog the system
*/
if ((int_status & HECC_CANGIF_BOIF) || (err_status & HECC_CANES_BO)) {
priv->can.state = CAN_STATE_BUS_OFF;
cf->can_id |= CAN_ERR_BUSOFF;
hecc_set_bit(priv, HECC_CANES, HECC_CANES_BO);
hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
/* Disable all interrupts in bus-off to avoid int hog */
hecc_write(priv, HECC_CANGIM, 0);
can_bus_off(ndev);
}
if (err_status & HECC_BUS_ERROR) {
++priv->can.can_stats.bus_error;
cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
cf->data[2] |= CAN_ERR_PROT_UNSPEC;
if (err_status & HECC_CANES_FE) {
hecc_set_bit(priv, HECC_CANES, HECC_CANES_FE);
cf->data[2] |= CAN_ERR_PROT_FORM;
}
if (err_status & HECC_CANES_BE) {
hecc_set_bit(priv, HECC_CANES, HECC_CANES_BE);
cf->data[2] |= CAN_ERR_PROT_BIT;
}
if (err_status & HECC_CANES_SE) {
hecc_set_bit(priv, HECC_CANES, HECC_CANES_SE);
cf->data[2] |= CAN_ERR_PROT_STUFF;
}
if (err_status & HECC_CANES_CRCE) {
hecc_set_bit(priv, HECC_CANES, HECC_CANES_CRCE);
cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ |
CAN_ERR_PROT_LOC_CRC_DEL;
}
if (err_status & HECC_CANES_ACKE) {
hecc_set_bit(priv, HECC_CANES, HECC_CANES_ACKE);
cf->data[3] |= CAN_ERR_PROT_LOC_ACK |
CAN_ERR_PROT_LOC_ACK_DEL;
}
}
netif_rx(skb);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
return 0;
}
static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
{
struct net_device *ndev = (struct net_device *)dev_id;
struct ti_hecc_priv *priv = netdev_priv(ndev);
struct net_device_stats *stats = &ndev->stats;
u32 mbxno, mbx_mask, int_status, err_status;
unsigned long ack, flags;
int_status = hecc_read(priv,
(priv->int_line) ? HECC_CANGIF1 : HECC_CANGIF0);
if (!int_status)
return IRQ_NONE;
err_status = hecc_read(priv, HECC_CANES);
if (err_status & (HECC_BUS_ERROR | HECC_CANES_BO |
HECC_CANES_EP | HECC_CANES_EW))
ti_hecc_error(ndev, int_status, err_status);
if (int_status & HECC_CANGIF_GMIF) {
while (priv->tx_tail - priv->tx_head > 0) {
mbxno = get_tx_tail_mb(priv);
mbx_mask = BIT(mbxno);
if (!(mbx_mask & hecc_read(priv, HECC_CANTA)))
break;
hecc_clear_bit(priv, HECC_CANMIM, mbx_mask);
hecc_write(priv, HECC_CANTA, mbx_mask);
spin_lock_irqsave(&priv->mbx_lock, flags);
hecc_clear_bit(priv, HECC_CANME, mbx_mask);
spin_unlock_irqrestore(&priv->mbx_lock, flags);
stats->tx_bytes += hecc_read_mbx(priv, mbxno,
HECC_CANMCF) & 0xF;
stats->tx_packets++;
can_led_event(ndev, CAN_LED_EVENT_TX);
can_get_echo_skb(ndev, mbxno);
--priv->tx_tail;
}
/* restart queue if wrap-up or if queue stalled on last pkt */
if (((priv->tx_head == priv->tx_tail) &&
((priv->tx_head & HECC_TX_MASK) != HECC_TX_MASK)) ||
(((priv->tx_tail & HECC_TX_MASK) == HECC_TX_MASK) &&
((priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK)))
netif_wake_queue(ndev);
/* Disable RX mailbox interrupts and let NAPI reenable them */
if (hecc_read(priv, HECC_CANRMP)) {
ack = hecc_read(priv, HECC_CANMIM);
ack &= BIT(HECC_MAX_TX_MBOX) - 1;
hecc_write(priv, HECC_CANMIM, ack);
napi_schedule(&priv->napi);
}
}
/* clear all interrupt conditions - read back to avoid spurious ints */
if (priv->int_line) {
hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
int_status = hecc_read(priv, HECC_CANGIF1);
} else {
hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
int_status = hecc_read(priv, HECC_CANGIF0);
}
return IRQ_HANDLED;
}
static int ti_hecc_open(struct net_device *ndev)
{
struct ti_hecc_priv *priv = netdev_priv(ndev);
int err;
err = request_irq(ndev->irq, ti_hecc_interrupt, IRQF_SHARED,
ndev->name, ndev);
if (err) {
netdev_err(ndev, "error requesting interrupt\n");
return err;
}
ti_hecc_transceiver_switch(priv, 1);
/* Open common can device */
err = open_candev(ndev);
if (err) {
netdev_err(ndev, "open_candev() failed %d\n", err);
ti_hecc_transceiver_switch(priv, 0);
free_irq(ndev->irq, ndev);
return err;
}
can_led_event(ndev, CAN_LED_EVENT_OPEN);
ti_hecc_start(ndev);
napi_enable(&priv->napi);
netif_start_queue(ndev);
return 0;
}
static int ti_hecc_close(struct net_device *ndev)
{
struct ti_hecc_priv *priv = netdev_priv(ndev);
netif_stop_queue(ndev);
napi_disable(&priv->napi);
ti_hecc_stop(ndev);
free_irq(ndev->irq, ndev);
close_candev(ndev);
ti_hecc_transceiver_switch(priv, 0);
can_led_event(ndev, CAN_LED_EVENT_STOP);
return 0;
}
static const struct net_device_ops ti_hecc_netdev_ops = {
.ndo_open = ti_hecc_open,
.ndo_stop = ti_hecc_close,
.ndo_start_xmit = ti_hecc_xmit,
};
static int ti_hecc_probe(struct platform_device *pdev)
{
struct net_device *ndev = (struct net_device *)0;
struct ti_hecc_priv *priv;
struct ti_hecc_platform_data *pdata;
struct resource *mem, *irq;
void __iomem *addr;
int err = -ENODEV;
pdata = dev_get_platdata(&pdev->dev);
if (!pdata) {
dev_err(&pdev->dev, "No platform data\n");
goto probe_exit;
}
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!mem) {
dev_err(&pdev->dev, "No mem resources\n");
goto probe_exit;
}
irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!irq) {
dev_err(&pdev->dev, "No irq resource\n");
goto probe_exit;
}
if (!request_mem_region(mem->start, resource_size(mem), pdev->name)) {
dev_err(&pdev->dev, "HECC region already claimed\n");
err = -EBUSY;
goto probe_exit;
}
addr = ioremap(mem->start, resource_size(mem));
if (!addr) {
dev_err(&pdev->dev, "ioremap failed\n");
err = -ENOMEM;
goto probe_exit_free_region;
}
ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX);
if (!ndev) {
dev_err(&pdev->dev, "alloc_candev failed\n");
err = -ENOMEM;
goto probe_exit_iounmap;
}
priv = netdev_priv(ndev);
priv->ndev = ndev;
priv->base = addr;
priv->scc_ram_offset = pdata->scc_ram_offset;
priv->hecc_ram_offset = pdata->hecc_ram_offset;
priv->mbx_offset = pdata->mbx_offset;
priv->int_line = pdata->int_line;
priv->transceiver_switch = pdata->transceiver_switch;
priv->can.bittiming_const = &ti_hecc_bittiming_const;
priv->can.do_set_mode = ti_hecc_do_set_mode;
priv->can.do_get_berr_counter = ti_hecc_get_berr_counter;
priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
spin_lock_init(&priv->mbx_lock);
ndev->irq = irq->start;
ndev->flags |= IFF_ECHO;
platform_set_drvdata(pdev, ndev);
SET_NETDEV_DEV(ndev, &pdev->dev);
ndev->netdev_ops = &ti_hecc_netdev_ops;
priv->clk = clk_get(&pdev->dev, "hecc_ck");
if (IS_ERR(priv->clk)) {
dev_err(&pdev->dev, "No clock available\n");
err = PTR_ERR(priv->clk);
priv->clk = NULL;
goto probe_exit_candev;
}
priv->can.clock.freq = clk_get_rate(priv->clk);
netif_napi_add(ndev, &priv->napi, ti_hecc_rx_poll,
HECC_DEF_NAPI_WEIGHT);
clk_enable(priv->clk);
err = register_candev(ndev);
if (err) {
dev_err(&pdev->dev, "register_candev() failed\n");
goto probe_exit_clk;
}
devm_can_led_init(ndev);
dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n",
priv->base, (u32) ndev->irq);
return 0;
probe_exit_clk:
clk_put(priv->clk);
probe_exit_candev:
free_candev(ndev);
probe_exit_iounmap:
iounmap(addr);
probe_exit_free_region:
release_mem_region(mem->start, resource_size(mem));
probe_exit:
return err;
}
static int ti_hecc_remove(struct platform_device *pdev)
{
struct resource *res;
struct net_device *ndev = platform_get_drvdata(pdev);
struct ti_hecc_priv *priv = netdev_priv(ndev);
unregister_candev(ndev);
clk_disable(priv->clk);
clk_put(priv->clk);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
iounmap(priv->base);
release_mem_region(res->start, resource_size(res));
free_candev(ndev);
return 0;
}
#ifdef CONFIG_PM
static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state)
{
struct net_device *dev = platform_get_drvdata(pdev);
struct ti_hecc_priv *priv = netdev_priv(dev);
if (netif_running(dev)) {
netif_stop_queue(dev);
netif_device_detach(dev);
}
hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
priv->can.state = CAN_STATE_SLEEPING;
clk_disable(priv->clk);
return 0;
}
static int ti_hecc_resume(struct platform_device *pdev)
{
struct net_device *dev = platform_get_drvdata(pdev);
struct ti_hecc_priv *priv = netdev_priv(dev);
clk_enable(priv->clk);
hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
priv->can.state = CAN_STATE_ERROR_ACTIVE;
if (netif_running(dev)) {
netif_device_attach(dev);
netif_start_queue(dev);
}
return 0;
}
#else
#define ti_hecc_suspend NULL
#define ti_hecc_resume NULL
#endif
/* TI HECC netdevice driver: platform driver structure */
static struct platform_driver ti_hecc_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
.probe = ti_hecc_probe,
.remove = ti_hecc_remove,
.suspend = ti_hecc_suspend,
.resume = ti_hecc_resume,
};
module_platform_driver(ti_hecc_driver);
MODULE_AUTHOR("Anant Gole <anantgole@ti.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION(DRV_DESC);
MODULE_ALIAS("platform:" DRV_NAME);
