/*
* CAN bus driver for Bosch M_CAN controller
*
* Copyright (C) 2014 Freescale Semiconductor, Inc.
* Dong Aisheng <b29396@freescale.com>
*
* Bosch M_CAN user manual can be obtained from:
* http://www.bosch-semiconductors.de/media/pdf_1/ipmodules_1/m_can/
* mcan_users_manual_v302.pdf
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/clk.h>
#include <linux/delay.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/can/dev.h>
/* napi related */
#define M_CAN_NAPI_WEIGHT 64
/* message ram configuration data length */
#define MRAM_CFG_LEN 8
/* registers definition */
enum m_can_reg {
M_CAN_CREL = 0x0,
M_CAN_ENDN = 0x4,
M_CAN_CUST = 0x8,
M_CAN_FBTP = 0xc,
M_CAN_TEST = 0x10,
M_CAN_RWD = 0x14,
M_CAN_CCCR = 0x18,
M_CAN_BTP = 0x1c,
M_CAN_TSCC = 0x20,
M_CAN_TSCV = 0x24,
M_CAN_TOCC = 0x28,
M_CAN_TOCV = 0x2c,
M_CAN_ECR = 0x40,
M_CAN_PSR = 0x44,
M_CAN_IR = 0x50,
M_CAN_IE = 0x54,
M_CAN_ILS = 0x58,
M_CAN_ILE = 0x5c,
M_CAN_GFC = 0x80,
M_CAN_SIDFC = 0x84,
M_CAN_XIDFC = 0x88,
M_CAN_XIDAM = 0x90,
M_CAN_HPMS = 0x94,
M_CAN_NDAT1 = 0x98,
M_CAN_NDAT2 = 0x9c,
M_CAN_RXF0C = 0xa0,
M_CAN_RXF0S = 0xa4,
M_CAN_RXF0A = 0xa8,
M_CAN_RXBC = 0xac,
M_CAN_RXF1C = 0xb0,
M_CAN_RXF1S = 0xb4,
M_CAN_RXF1A = 0xb8,
M_CAN_RXESC = 0xbc,
M_CAN_TXBC = 0xc0,
M_CAN_TXFQS = 0xc4,
M_CAN_TXESC = 0xc8,
M_CAN_TXBRP = 0xcc,
M_CAN_TXBAR = 0xd0,
M_CAN_TXBCR = 0xd4,
M_CAN_TXBTO = 0xd8,
M_CAN_TXBCF = 0xdc,
M_CAN_TXBTIE = 0xe0,
M_CAN_TXBCIE = 0xe4,
M_CAN_TXEFC = 0xf0,
M_CAN_TXEFS = 0xf4,
M_CAN_TXEFA = 0xf8,
};
/* m_can lec values */
enum m_can_lec_type {
LEC_NO_ERROR = 0,
LEC_STUFF_ERROR,
LEC_FORM_ERROR,
LEC_ACK_ERROR,
LEC_BIT1_ERROR,
LEC_BIT0_ERROR,
LEC_CRC_ERROR,
LEC_UNUSED,
};
enum m_can_mram_cfg {
MRAM_SIDF = 0,
MRAM_XIDF,
MRAM_RXF0,
MRAM_RXF1,
MRAM_RXB,
MRAM_TXE,
MRAM_TXB,
MRAM_CFG_NUM,
};
/* Test Register (TEST) */
#define TEST_LBCK BIT(4)
/* CC Control Register(CCCR) */
#define CCCR_TEST BIT(7)
#define CCCR_MON BIT(5)
#define CCCR_CCE BIT(1)
#define CCCR_INIT BIT(0)
/* Bit Timing & Prescaler Register (BTP) */
#define BTR_BRP_MASK 0x3ff
#define BTR_BRP_SHIFT 16
#define BTR_TSEG1_SHIFT 8
#define BTR_TSEG1_MASK (0x3f << BTR_TSEG1_SHIFT)
#define BTR_TSEG2_SHIFT 4
#define BTR_TSEG2_MASK (0xf << BTR_TSEG2_SHIFT)
#define BTR_SJW_SHIFT 0
#define BTR_SJW_MASK 0xf
/* Error Counter Register(ECR) */
#define ECR_RP BIT(15)
#define ECR_REC_SHIFT 8
#define ECR_REC_MASK (0x7f << ECR_REC_SHIFT)
#define ECR_TEC_SHIFT 0
#define ECR_TEC_MASK 0xff
/* Protocol Status Register(PSR) */
#define PSR_BO BIT(7)
#define PSR_EW BIT(6)
#define PSR_EP BIT(5)
#define PSR_LEC_MASK 0x7
/* Interrupt Register(IR) */
#define IR_ALL_INT 0xffffffff
#define IR_STE BIT(31)
#define IR_FOE BIT(30)
#define IR_ACKE BIT(29)
#define IR_BE BIT(28)
#define IR_CRCE BIT(27)
#define IR_WDI BIT(26)
#define IR_BO BIT(25)
#define IR_EW BIT(24)
#define IR_EP BIT(23)
#define IR_ELO BIT(22)
#define IR_BEU BIT(21)
#define IR_BEC BIT(20)
#define IR_DRX BIT(19)
#define IR_TOO BIT(18)
#define IR_MRAF BIT(17)
#define IR_TSW BIT(16)
#define IR_TEFL BIT(15)
#define IR_TEFF BIT(14)
#define IR_TEFW BIT(13)
#define IR_TEFN BIT(12)
#define IR_TFE BIT(11)
#define IR_TCF BIT(10)
#define IR_TC BIT(9)
#define IR_HPM BIT(8)
#define IR_RF1L BIT(7)
#define IR_RF1F BIT(6)
#define IR_RF1W BIT(5)
#define IR_RF1N BIT(4)
#define IR_RF0L BIT(3)
#define IR_RF0F BIT(2)
#define IR_RF0W BIT(1)
#define IR_RF0N BIT(0)
#define IR_ERR_STATE (IR_BO | IR_EW | IR_EP)
#define IR_ERR_LEC (IR_STE | IR_FOE | IR_ACKE | IR_BE | IR_CRCE)
#define IR_ERR_BUS (IR_ERR_LEC | IR_WDI | IR_ELO | IR_BEU | \
IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | \
IR_RF1L | IR_RF0L)
#define IR_ERR_ALL (IR_ERR_STATE | IR_ERR_BUS)
/* Interrupt Line Select (ILS) */
#define ILS_ALL_INT0 0x0
#define ILS_ALL_INT1 0xFFFFFFFF
/* Interrupt Line Enable (ILE) */
#define ILE_EINT0 BIT(0)
#define ILE_EINT1 BIT(1)
/* Rx FIFO 0/1 Configuration (RXF0C/RXF1C) */
#define RXFC_FWM_OFF 24
#define RXFC_FWM_MASK 0x7f
#define RXFC_FWM_1 (1 << RXFC_FWM_OFF)
#define RXFC_FS_OFF 16
#define RXFC_FS_MASK 0x7f
/* Rx FIFO 0/1 Status (RXF0S/RXF1S) */
#define RXFS_RFL BIT(25)
#define RXFS_FF BIT(24)
#define RXFS_FPI_OFF 16
#define RXFS_FPI_MASK 0x3f0000
#define RXFS_FGI_OFF 8
#define RXFS_FGI_MASK 0x3f00
#define RXFS_FFL_MASK 0x7f
/* Rx Buffer / FIFO Element Size Configuration (RXESC) */
#define M_CAN_RXESC_8BYTES 0x0
/* Tx Buffer Configuration(TXBC) */
#define TXBC_NDTB_OFF 16
#define TXBC_NDTB_MASK 0x3f
/* Tx Buffer Element Size Configuration(TXESC) */
#define TXESC_TBDS_8BYTES 0x0
/* Tx Event FIFO Con.guration (TXEFC) */
#define TXEFC_EFS_OFF 16
#define TXEFC_EFS_MASK 0x3f
/* Message RAM Configuration (in bytes) */
#define SIDF_ELEMENT_SIZE 4
#define XIDF_ELEMENT_SIZE 8
#define RXF0_ELEMENT_SIZE 16
#define RXF1_ELEMENT_SIZE 16
#define RXB_ELEMENT_SIZE 16
#define TXE_ELEMENT_SIZE 8
#define TXB_ELEMENT_SIZE 16
/* Message RAM Elements */
#define M_CAN_FIFO_ID 0x0
#define M_CAN_FIFO_DLC 0x4
#define M_CAN_FIFO_DATA(n) (0x8 + ((n) << 2))
/* Rx Buffer Element */
#define RX_BUF_ESI BIT(31)
#define RX_BUF_XTD BIT(30)
#define RX_BUF_RTR BIT(29)
/* Tx Buffer Element */
#define TX_BUF_XTD BIT(30)
#define TX_BUF_RTR BIT(29)
/* address offset and element number for each FIFO/Buffer in the Message RAM */
struct mram_cfg {
u16 off;
u8 num;
};
/* m_can private data structure */
struct m_can_priv {
struct can_priv can; /* must be the first member */
struct napi_struct napi;
struct net_device *dev;
struct device *device;
struct clk *hclk;
struct clk *cclk;
void __iomem *base;
u32 irqstatus;
/* message ram configuration */
void __iomem *mram_base;
struct mram_cfg mcfg[MRAM_CFG_NUM];
};
static inline u32 m_can_read(const struct m_can_priv *priv, enum m_can_reg reg)
{
return readl(priv->base + reg);
}
static inline void m_can_write(const struct m_can_priv *priv,
enum m_can_reg reg, u32 val)
{
writel(val, priv->base + reg);
}
static inline u32 m_can_fifo_read(const struct m_can_priv *priv,
u32 fgi, unsigned int offset)
{
return readl(priv->mram_base + priv->mcfg[MRAM_RXF0].off +
fgi * RXF0_ELEMENT_SIZE + offset);
}
static inline void m_can_fifo_write(const struct m_can_priv *priv,
u32 fpi, unsigned int offset, u32 val)
{
return writel(val, priv->mram_base + priv->mcfg[MRAM_TXB].off +
fpi * TXB_ELEMENT_SIZE + offset);
}
static inline void m_can_config_endisable(const struct m_can_priv *priv,
bool enable)
{
u32 cccr = m_can_read(priv, M_CAN_CCCR);
u32 timeout = 10;
u32 val = 0;
if (enable) {
/* enable m_can configuration */
m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT);
udelay(5);
/* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */
m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE);
} else {
m_can_write(priv, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE));
}
/* there's a delay for module initialization */
if (enable)
val = CCCR_INIT | CCCR_CCE;
while ((m_can_read(priv, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) {
if (timeout == 0) {
netdev_warn(priv->dev, "Failed to init module\n");
return;
}
timeout--;
udelay(1);
}
}
static inline void m_can_enable_all_interrupts(const struct m_can_priv *priv)
{
m_can_write(priv, M_CAN_ILE, ILE_EINT0 | ILE_EINT1);
}
static inline void m_can_disable_all_interrupts(const struct m_can_priv *priv)
{
m_can_write(priv, M_CAN_ILE, 0x0);
}
static void m_can_read_fifo(const struct net_device *dev, struct can_frame *cf,
u32 rxfs)
{
struct m_can_priv *priv = netdev_priv(dev);
u32 id, fgi, dlc;
/* calculate the fifo get index for where to read data */
fgi = (rxfs & RXFS_FGI_MASK) >> RXFS_FGI_OFF;
id = m_can_fifo_read(priv, fgi, M_CAN_FIFO_ID);
if (id & RX_BUF_XTD)
cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG;
else
cf->can_id = (id >> 18) & CAN_SFF_MASK;
dlc = m_can_fifo_read(priv, fgi, M_CAN_FIFO_DLC);
cf->can_dlc = get_can_dlc((dlc >> 16) & 0x0F);
if (id & RX_BUF_RTR) {
cf->can_id |= CAN_RTR_FLAG;
} else {
*(u32 *)(cf->data + 0) = m_can_fifo_read(priv, fgi,
M_CAN_FIFO_DATA(0));
*(u32 *)(cf->data + 4) = m_can_fifo_read(priv, fgi,
M_CAN_FIFO_DATA(1));
}
/* acknowledge rx fifo 0 */
m_can_write(priv, M_CAN_RXF0A, fgi);
}
static int m_can_do_rx_poll(struct net_device *dev, int quota)
{
struct m_can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
struct sk_buff *skb;
struct can_frame *frame;
u32 pkts = 0;
u32 rxfs;
rxfs = m_can_read(priv, M_CAN_RXF0S);
if (!(rxfs & RXFS_FFL_MASK)) {
netdev_dbg(dev, "no messages in fifo0\n");
return 0;
}
while ((rxfs & RXFS_FFL_MASK) && (quota > 0)) {
if (rxfs & RXFS_RFL)
netdev_warn(dev, "Rx FIFO 0 Message Lost\n");
skb = alloc_can_skb(dev, &frame);
if (!skb) {
stats->rx_dropped++;
return pkts;
}
m_can_read_fifo(dev, frame, rxfs);
stats->rx_packets++;
stats->rx_bytes += frame->can_dlc;
netif_receive_skb(skb);
quota--;
pkts++;
rxfs = m_can_read(priv, M_CAN_RXF0S);
}
if (pkts)
can_led_event(dev, CAN_LED_EVENT_RX);
return pkts;
}
static int m_can_handle_lost_msg(struct net_device *dev)
{
struct net_device_stats *stats = &dev->stats;
struct sk_buff *skb;
struct can_frame *frame;
netdev_err(dev, "msg lost in rxf0\n");
stats->rx_errors++;
stats->rx_over_errors++;
skb = alloc_can_err_skb(dev, &frame);
if (unlikely(!skb))
return 0;
frame->can_id |= CAN_ERR_CRTL;
frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
netif_receive_skb(skb);
return 1;
}
static int m_can_handle_lec_err(struct net_device *dev,
enum m_can_lec_type lec_type)
{
struct m_can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
struct can_frame *cf;
struct sk_buff *skb;
priv->can.can_stats.bus_error++;
stats->rx_errors++;
/* propagate the error condition to the CAN stack */
skb = alloc_can_err_skb(dev, &cf);
if (unlikely(!skb))
return 0;
/* check for 'last error code' which tells us the
* type of the last error to occur on the CAN bus
*/
cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
cf->data[2] |= CAN_ERR_PROT_UNSPEC;
switch (lec_type) {
case LEC_STUFF_ERROR:
netdev_dbg(dev, "stuff error\n");
cf->data[2] |= CAN_ERR_PROT_STUFF;
break;
case LEC_FORM_ERROR:
netdev_dbg(dev, "form error\n");
cf->data[2] |= CAN_ERR_PROT_FORM;
break;
case LEC_ACK_ERROR:
netdev_dbg(dev, "ack error\n");
cf->data[3] |= (CAN_ERR_PROT_LOC_ACK |
CAN_ERR_PROT_LOC_ACK_DEL);
break;
case LEC_BIT1_ERROR:
netdev_dbg(dev, "bit1 error\n");
cf->data[2] |= CAN_ERR_PROT_BIT1;
break;
case LEC_BIT0_ERROR:
netdev_dbg(dev, "bit0 error\n");
cf->data[2] |= CAN_ERR_PROT_BIT0;
break;
case LEC_CRC_ERROR:
netdev_dbg(dev, "CRC error\n");
cf->data[3] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
CAN_ERR_PROT_LOC_CRC_DEL);
break;
default:
break;
}
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
netif_receive_skb(skb);
return 1;
}
static int __m_can_get_berr_counter(const struct net_device *dev,
struct can_berr_counter *bec)
{
struct m_can_priv *priv = netdev_priv(dev);
unsigned int ecr;
ecr = m_can_read(priv, M_CAN_ECR);
bec->rxerr = (ecr & ECR_REC_MASK) >> ECR_REC_SHIFT;
bec->txerr = ecr & ECR_TEC_MASK;
return 0;
}
static int m_can_get_berr_counter(const struct net_device *dev,
struct can_berr_counter *bec)
{
struct m_can_priv *priv = netdev_priv(dev);
int err;
err = clk_prepare_enable(priv->hclk);
if (err)
return err;
err = clk_prepare_enable(priv->cclk);
if (err) {
clk_disable_unprepare(priv->hclk);
return err;
}
__m_can_get_berr_counter(dev, bec);
clk_disable_unprepare(priv->cclk);
clk_disable_unprepare(priv->hclk);
return 0;
}
static int m_can_handle_state_change(struct net_device *dev,
enum can_state new_state)
{
struct m_can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
struct can_frame *cf;
struct sk_buff *skb;
struct can_berr_counter bec;
unsigned int ecr;
switch (new_state) {
case CAN_STATE_ERROR_ACTIVE:
/* error warning state */
priv->can.can_stats.error_warning++;
priv->can.state = CAN_STATE_ERROR_WARNING;
break;
case CAN_STATE_ERROR_PASSIVE:
/* error passive state */
priv->can.can_stats.error_passive++;
priv->can.state = CAN_STATE_ERROR_PASSIVE;
break;
case CAN_STATE_BUS_OFF:
/* bus-off state */
priv->can.state = CAN_STATE_BUS_OFF;
m_can_disable_all_interrupts(priv);
can_bus_off(dev);
break;
default:
break;
}
/* propagate the error condition to the CAN stack */
skb = alloc_can_err_skb(dev, &cf);
if (unlikely(!skb))
return 0;
__m_can_get_berr_counter(dev, &bec);
switch (new_state) {
case CAN_STATE_ERROR_ACTIVE:
/* error warning state */
cf->can_id |= CAN_ERR_CRTL;
cf->data[1] = (bec.txerr > bec.rxerr) ?
CAN_ERR_CRTL_TX_WARNING :
CAN_ERR_CRTL_RX_WARNING;
cf->data[6] = bec.txerr;
cf->data[7] = bec.rxerr;
break;
case CAN_STATE_ERROR_PASSIVE:
/* error passive state */
cf->can_id |= CAN_ERR_CRTL;
ecr = m_can_read(priv, M_CAN_ECR);
if (ecr & ECR_RP)
cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
if (bec.txerr > 127)
cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
cf->data[6] = bec.txerr;
cf->data[7] = bec.rxerr;
break;
case CAN_STATE_BUS_OFF:
/* bus-off state */
cf->can_id |= CAN_ERR_BUSOFF;
break;
default:
break;
}
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
netif_receive_skb(skb);
return 1;
}
static int m_can_handle_state_errors(struct net_device *dev, u32 psr)
{
struct m_can_priv *priv = netdev_priv(dev);
int work_done = 0;
if ((psr & PSR_EW) &&
(priv->can.state != CAN_STATE_ERROR_WARNING)) {
netdev_dbg(dev, "entered error warning state\n");
work_done += m_can_handle_state_change(dev,
CAN_STATE_ERROR_WARNING);
}
if ((psr & PSR_EP) &&
(priv->can.state != CAN_STATE_ERROR_PASSIVE)) {
netdev_dbg(dev, "entered error warning state\n");
work_done += m_can_handle_state_change(dev,
CAN_STATE_ERROR_PASSIVE);
}
if ((psr & PSR_BO) &&
(priv->can.state != CAN_STATE_BUS_OFF)) {
netdev_dbg(dev, "entered error warning state\n");
work_done += m_can_handle_state_change(dev,
CAN_STATE_BUS_OFF);
}
return work_done;
}
static void m_can_handle_other_err(struct net_device *dev, u32 irqstatus)
{
if (irqstatus & IR_WDI)
netdev_err(dev, "Message RAM Watchdog event due to missing READY\n");
if (irqstatus & IR_BEU)
netdev_err(dev, "Error Logging Overflow\n");
if (irqstatus & IR_BEU)
netdev_err(dev, "Bit Error Uncorrected\n");
if (irqstatus & IR_BEC)
netdev_err(dev, "Bit Error Corrected\n");
if (irqstatus & IR_TOO)
netdev_err(dev, "Timeout reached\n");
if (irqstatus & IR_MRAF)
netdev_err(dev, "Message RAM access failure occurred\n");
}
static inline bool is_lec_err(u32 psr)
{
psr &= LEC_UNUSED;
return psr && (psr != LEC_UNUSED);
}
static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
u32 psr)
{
struct m_can_priv *priv = netdev_priv(dev);
int work_done = 0;
if (irqstatus & IR_RF0L)
work_done += m_can_handle_lost_msg(dev);
/* handle lec errors on the bus */
if ((priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
is_lec_err(psr))
work_done += m_can_handle_lec_err(dev, psr & LEC_UNUSED);
/* other unproccessed error interrupts */
m_can_handle_other_err(dev, irqstatus);
return work_done;
}
static int m_can_poll(struct napi_struct *napi, int quota)
{
struct net_device *dev = napi->dev;
struct m_can_priv *priv = netdev_priv(dev);
int work_done = 0;
u32 irqstatus, psr;
irqstatus = priv->irqstatus | m_can_read(priv, M_CAN_IR);
if (!irqstatus)
goto end;
psr = m_can_read(priv, M_CAN_PSR);
if (irqstatus & IR_ERR_STATE)
work_done += m_can_handle_state_errors(dev, psr);
if (irqstatus & IR_ERR_BUS)
work_done += m_can_handle_bus_errors(dev, irqstatus, psr);
if (irqstatus & IR_RF0N)
work_done += m_can_do_rx_poll(dev, (quota - work_done));
if (work_done < quota) {
napi_complete(napi);
m_can_enable_all_interrupts(priv);
}
end:
return work_done;
}
static irqreturn_t m_can_isr(int irq, void *dev_id)
{
struct net_device *dev = (struct net_device *)dev_id;
struct m_can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
u32 ir;
ir = m_can_read(priv, M_CAN_IR);
if (!ir)
return IRQ_NONE;
/* ACK all irqs */
if (ir & IR_ALL_INT)
m_can_write(priv, M_CAN_IR, ir);
/* schedule NAPI in case of
* - rx IRQ
* - state change IRQ
* - bus error IRQ and bus error reporting
*/
if ((ir & IR_RF0N) || (ir & IR_ERR_ALL)) {
priv->irqstatus = ir;
m_can_disable_all_interrupts(priv);
napi_schedule(&priv->napi);
}
/* transmission complete interrupt */
if (ir & IR_TC) {
stats->tx_bytes += can_get_echo_skb(dev, 0);
stats->tx_packets++;
can_led_event(dev, CAN_LED_EVENT_TX);
netif_wake_queue(dev);
}
return IRQ_HANDLED;
}
static const struct can_bittiming_const m_can_bittiming_const = {
.name = KBUILD_MODNAME,
.tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */
.tseg1_max = 64,
.tseg2_min = 1, /* Time segment 2 = phase_seg2 */
.tseg2_max = 16,
.sjw_max = 16,
.brp_min = 1,
.brp_max = 1024,
.brp_inc = 1,
};
static int m_can_set_bittiming(struct net_device *dev)
{
struct m_can_priv *priv = netdev_priv(dev);
const struct can_bittiming *bt = &priv->can.bittiming;
u16 brp, sjw, tseg1, tseg2;
u32 reg_btp;
brp = bt->brp - 1;
sjw = bt->sjw - 1;
tseg1 = bt->prop_seg + bt->phase_seg1 - 1;
tseg2 = bt->phase_seg2 - 1;
reg_btp = (brp << BTR_BRP_SHIFT) | (sjw << BTR_SJW_SHIFT) |
(tseg1 << BTR_TSEG1_SHIFT) | (tseg2 << BTR_TSEG2_SHIFT);
m_can_write(priv, M_CAN_BTP, reg_btp);
netdev_dbg(dev, "setting BTP 0x%x\n", reg_btp);
return 0;
}
/* Configure M_CAN chip:
* - set rx buffer/fifo element size
* - configure rx fifo
* - accept non-matching frame into fifo 0
* - configure tx buffer
* - configure mode
* - setup bittiming
*/
static void m_can_chip_config(struct net_device *dev)
{
struct m_can_priv *priv = netdev_priv(dev);
u32 cccr, test;
m_can_config_endisable(priv, true);
/* RX Buffer/FIFO Element Size 8 bytes data field */
m_can_write(priv, M_CAN_RXESC, M_CAN_RXESC_8BYTES);
/* Accept Non-matching Frames Into FIFO 0 */
m_can_write(priv, M_CAN_GFC, 0x0);
/* only support one Tx Buffer currently */
m_can_write(priv, M_CAN_TXBC, (1 << TXBC_NDTB_OFF) |
priv->mcfg[MRAM_TXB].off);
/* only support 8 bytes firstly */
m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_8BYTES);
m_can_write(priv, M_CAN_TXEFC, (1 << TXEFC_EFS_OFF) |
priv->mcfg[MRAM_TXE].off);
/* rx fifo configuration, blocking mode, fifo size 1 */
m_can_write(priv, M_CAN_RXF0C,
(priv->mcfg[MRAM_RXF0].num << RXFC_FS_OFF) |
RXFC_FWM_1 | priv->mcfg[MRAM_RXF0].off);
m_can_write(priv, M_CAN_RXF1C,
(priv->mcfg[MRAM_RXF1].num << RXFC_FS_OFF) |
RXFC_FWM_1 | priv->mcfg[MRAM_RXF1].off);
cccr = m_can_read(priv, M_CAN_CCCR);
cccr &= ~(CCCR_TEST | CCCR_MON);
test = m_can_read(priv, M_CAN_TEST);
test &= ~TEST_LBCK;
if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
cccr |= CCCR_MON;
if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
cccr |= CCCR_TEST;
test |= TEST_LBCK;
}
m_can_write(priv, M_CAN_CCCR, cccr);
m_can_write(priv, M_CAN_TEST, test);
/* enable interrupts */
m_can_write(priv, M_CAN_IR, IR_ALL_INT);
if (!(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
m_can_write(priv, M_CAN_IE, IR_ALL_INT & ~IR_ERR_LEC);
else
m_can_write(priv, M_CAN_IE, IR_ALL_INT);
/* route all interrupts to INT0 */
m_can_write(priv, M_CAN_ILS, ILS_ALL_INT0);
/* set bittiming params */
m_can_set_bittiming(dev);
m_can_config_endisable(priv, false);
}
static void m_can_start(struct net_device *dev)
{
struct m_can_priv *priv = netdev_priv(dev);
/* basic m_can configuration */
m_can_chip_config(dev);
priv->can.state = CAN_STATE_ERROR_ACTIVE;
m_can_enable_all_interrupts(priv);
}
static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
{
switch (mode) {
case CAN_MODE_START:
m_can_start(dev);
netif_wake_queue(dev);
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static void free_m_can_dev(struct net_device *dev)
{
free_candev(dev);
}
static struct net_device *alloc_m_can_dev(void)
{
struct net_device *dev;
struct m_can_priv *priv;
dev = alloc_candev(sizeof(*priv), 1);
if (!dev)
return NULL;
priv = netdev_priv(dev);
netif_napi_add(dev, &priv->napi, m_can_poll, M_CAN_NAPI_WEIGHT);
priv->dev = dev;
priv->can.bittiming_const = &m_can_bittiming_const;
priv->can.do_set_mode = m_can_set_mode;
priv->can.do_get_berr_counter = m_can_get_berr_counter;
priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
CAN_CTRLMODE_LISTENONLY |
CAN_CTRLMODE_BERR_REPORTING;
return dev;
}
static int m_can_open(struct net_device *dev)
{
struct m_can_priv *priv = netdev_priv(dev);
int err;
err = clk_prepare_enable(priv->hclk);
if (err)
return err;
err = clk_prepare_enable(priv->cclk);
if (err)
goto exit_disable_hclk;
/* open the can device */
err = open_candev(dev);
if (err) {
netdev_err(dev, "failed to open can device\n");
goto exit_disable_cclk;
}
/* register interrupt handler */
err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name,
dev);
if (err < 0) {
netdev_err(dev, "failed to request interrupt\n");
goto exit_irq_fail;
}
/* start the m_can controller */
m_can_start(dev);
can_led_event(dev, CAN_LED_EVENT_OPEN);
napi_enable(&priv->napi);
netif_start_queue(dev);
return 0;
exit_irq_fail:
close_candev(dev);
exit_disable_cclk:
clk_disable_unprepare(priv->cclk);
exit_disable_hclk:
clk_disable_unprepare(priv->hclk);
return err;
}
static void m_can_stop(struct net_device *dev)
{
struct m_can_priv *priv = netdev_priv(dev);
/* disable all interrupts */
m_can_disable_all_interrupts(priv);
clk_disable_unprepare(priv->hclk);
clk_disable_unprepare(priv->cclk);
/* set the state as STOPPED */
priv->can.state = CAN_STATE_STOPPED;
}
static int m_can_close(struct net_device *dev)
{
struct m_can_priv *priv = netdev_priv(dev);
netif_stop_queue(dev);
napi_disable(&priv->napi);
m_can_stop(dev);
free_irq(dev->irq, dev);
close_candev(dev);
can_led_event(dev, CAN_LED_EVENT_STOP);
return 0;
}
static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct m_can_priv *priv = netdev_priv(dev);
struct can_frame *cf = (struct can_frame *)skb->data;
u32 id;
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
netif_stop_queue(dev);
if (cf->can_id & CAN_EFF_FLAG) {
id = cf->can_id & CAN_EFF_MASK;
id |= TX_BUF_XTD;
} else {
id = ((cf->can_id & CAN_SFF_MASK) << 18);
}
if (cf->can_id & CAN_RTR_FLAG)
id |= TX_BUF_RTR;
/* message ram configuration */
m_can_fifo_write(priv, 0, M_CAN_FIFO_ID, id);
m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, cf->can_dlc << 16);
m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(0), *(u32 *)(cf->data + 0));
m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(1), *(u32 *)(cf->data + 4));
can_put_echo_skb(skb, dev, 0);
/* enable first TX buffer to start transfer */
m_can_write(priv, M_CAN_TXBTIE, 0x1);
m_can_write(priv, M_CAN_TXBAR, 0x1);
return NETDEV_TX_OK;
}
static const struct net_device_ops m_can_netdev_ops = {
.ndo_open = m_can_open,
.ndo_stop = m_can_close,
.ndo_start_xmit = m_can_start_xmit,
.ndo_change_mtu = can_change_mtu,
};
static int register_m_can_dev(struct net_device *dev)
{
dev->flags |= IFF_ECHO; /* we support local echo */
dev->netdev_ops = &m_can_netdev_ops;
return register_candev(dev);
}
static int m_can_of_parse_mram(struct platform_device *pdev,
struct m_can_priv *priv)
{
struct device_node *np = pdev->dev.of_node;
struct resource *res;
void __iomem *addr;
u32 out_val[MRAM_CFG_LEN];
int i, start, end, ret;
/* message ram could be shared */
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
if (!res)
return -ENODEV;
addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
if (!addr)
return -ENOMEM;
/* get message ram configuration */
ret = of_property_read_u32_array(np, "bosch,mram-cfg",
out_val, sizeof(out_val) / 4);
if (ret) {
dev_err(&pdev->dev, "can not get message ram configuration\n");
return -ENODEV;
}
priv->mram_base = addr;
priv->mcfg[MRAM_SIDF].off = out_val[0];
priv->mcfg[MRAM_SIDF].num = out_val[1];
priv->mcfg[MRAM_XIDF].off = priv->mcfg[MRAM_SIDF].off +
priv->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE;
priv->mcfg[MRAM_XIDF].num = out_val[2];
priv->mcfg[MRAM_RXF0].off = priv->mcfg[MRAM_XIDF].off +
priv->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE;
priv->mcfg[MRAM_RXF0].num = out_val[3] & RXFC_FS_MASK;
priv->mcfg[MRAM_RXF1].off = priv->mcfg[MRAM_RXF0].off +
priv->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE;
priv->mcfg[MRAM_RXF1].num = out_val[4] & RXFC_FS_MASK;
priv->mcfg[MRAM_RXB].off = priv->mcfg[MRAM_RXF1].off +
priv->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE;
priv->mcfg[MRAM_RXB].num = out_val[5];
priv->mcfg[MRAM_TXE].off = priv->mcfg[MRAM_RXB].off +
priv->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE;
priv->mcfg[MRAM_TXE].num = out_val[6];
priv->mcfg[MRAM_TXB].off = priv->mcfg[MRAM_TXE].off +
priv->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE;
priv->mcfg[MRAM_TXB].num = out_val[7] & TXBC_NDTB_MASK;
dev_dbg(&pdev->dev, "mram_base %p sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",
priv->mram_base,
priv->mcfg[MRAM_SIDF].off, priv->mcfg[MRAM_SIDF].num,
priv->mcfg[MRAM_XIDF].off, priv->mcfg[MRAM_XIDF].num,
priv->mcfg[MRAM_RXF0].off, priv->mcfg[MRAM_RXF0].num,
priv->mcfg[MRAM_RXF1].off, priv->mcfg[MRAM_RXF1].num,
priv->mcfg[MRAM_RXB].off, priv->mcfg[MRAM_RXB].num,
priv->mcfg[MRAM_TXE].off, priv->mcfg[MRAM_TXE].num,
priv->mcfg[MRAM_TXB].off, priv->mcfg[MRAM_TXB].num);
/* initialize the entire Message RAM in use to avoid possible
* ECC/parity checksum errors when reading an uninitialized buffer
*/
start = priv->mcfg[MRAM_SIDF].off;
end = priv->mcfg[MRAM_TXB].off +
priv->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
for (i = start; i < end; i += 4)
writel(0x0, priv->mram_base + i);
return 0;
}
static int m_can_plat_probe(struct platform_device *pdev)
{
struct net_device *dev;
struct m_can_priv *priv;
struct resource *res;
void __iomem *addr;
struct clk *hclk, *cclk;
int irq, ret;
hclk = devm_clk_get(&pdev->dev, "hclk");
cclk = devm_clk_get(&pdev->dev, "cclk");
if (IS_ERR(hclk) || IS_ERR(cclk)) {
dev_err(&pdev->dev, "no clock find\n");
return -ENODEV;
}
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");
addr = devm_ioremap_resource(&pdev->dev, res);
irq = platform_get_irq_byname(pdev, "int0");
if (IS_ERR(addr) || irq < 0)
return -EINVAL;
/* allocate the m_can device */
dev = alloc_m_can_dev();
if (!dev)
return -ENOMEM;
priv = netdev_priv(dev);
dev->irq = irq;
priv->base = addr;
priv->device = &pdev->dev;
priv->hclk = hclk;
priv->cclk = cclk;
priv->can.clock.freq = clk_get_rate(cclk);
ret = m_can_of_parse_mram(pdev, priv);
if (ret)
goto failed_free_dev;
platform_set_drvdata(pdev, dev);
SET_NETDEV_DEV(dev, &pdev->dev);
ret = register_m_can_dev(dev);
if (ret) {
dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
KBUILD_MODNAME, ret);
goto failed_free_dev;
}
devm_can_led_init(dev);
dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
KBUILD_MODNAME, priv->base, dev->irq);
return 0;
failed_free_dev:
free_m_can_dev(dev);
return ret;
}
static __maybe_unused int m_can_suspend(struct device *dev)
{
struct net_device *ndev = dev_get_drvdata(dev);
struct m_can_priv *priv = netdev_priv(ndev);
if (netif_running(ndev)) {
netif_stop_queue(ndev);
netif_device_detach(ndev);
}
/* TODO: enter low power */
priv->can.state = CAN_STATE_SLEEPING;
return 0;
}
static __maybe_unused int m_can_resume(struct device *dev)
{
struct net_device *ndev = dev_get_drvdata(dev);
struct m_can_priv *priv = netdev_priv(ndev);
/* TODO: exit low power */
priv->can.state = CAN_STATE_ERROR_ACTIVE;
if (netif_running(ndev)) {
netif_device_attach(ndev);
netif_start_queue(ndev);
}
return 0;
}
static void unregister_m_can_dev(struct net_device *dev)
{
unregister_candev(dev);
}
static int m_can_plat_remove(struct platform_device *pdev)
{
struct net_device *dev = platform_get_drvdata(pdev);
unregister_m_can_dev(dev);
platform_set_drvdata(pdev, NULL);
free_m_can_dev(dev);
return 0;
}
static const struct dev_pm_ops m_can_pmops = {
SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
};
static const struct of_device_id m_can_of_table[] = {
{ .compatible = "bosch,m_can", .data = NULL },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, m_can_of_table);
static struct platform_driver m_can_plat_driver = {
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = m_can_of_table,
.pm = &m_can_pmops,
},
.probe = m_can_plat_probe,
.remove = m_can_plat_remove,
};
module_platform_driver(m_can_plat_driver);
MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");
