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mcan-linux-driver/drivers/net/can/m_can/m_can.c
Mario Huettel 1f6deec3fb can: m_can: Enable TX FIFO Handling for M_CAN IP version >= v3.1.x 
* Added defines for TX Event FIFO Element
* Adapted ndo_start_xmit function.
  For versions >= v3.1.x it uses the TX FIFO to optimize the data
  throughput. It stores the echo skb at the same index as in the
  M_CAN's TX FIFO. The frame's message marker is set to this index.
  This message marker is received in the TX Event FIFO after
  the message was successfully transmitted. It is used to echo the
  correct echo skb back to the network stack.
* Added m_can_echo_tx_event function. It reads all received
  message markers in the TX Event FIFO and loops back the
  corresponding echo skbs.
* ISR checks for new TX Event Entry interrupt for version >= 3.1.x.

Signed-off-by: Mario Huettel <mario.huettel@gmx.net>
2017-04-26 13:13:46 +02:00

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/*
* 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/iopoll.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_DBTP = 0xc,
M_CAN_TEST = 0x10,
M_CAN_RWD = 0x14,
M_CAN_CCCR = 0x18,
M_CAN_NBTP = 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,
/* TDCR Register only available for version >=3.1.x */
M_CAN_TDCR = 0x48,
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,
};
/* Core Release Register (CREL) */
#define CREL_REL_SHIFT 28
#define CREL_REL_MASK (0xF << CREL_REL_SHIFT)
#define CREL_STEP_SHIFT 24
#define CREL_STEP_MASK (0xF << CREL_STEP_SHIFT)
#define CREL_SUBSTEP_SHIFT 20
#define CREL_SUBSTEP_MASK (0xF << CREL_SUBSTEP_SHIFT)
/* Data Bit Timing & Prescaler Register (DBTP) */
#define DBTP_TDC BIT(23)
#define DBTP_DBRP_SHIFT 16
#define DBTP_DBRP_MASK (0x1f << DBTP_DBRP_SHIFT)
#define DBTP_DTSEG1_SHIFT 8
#define DBTP_DTSEG1_MASK (0x1f << DBTP_DTSEG1_SHIFT)
#define DBTP_DTSEG2_SHIFT 4
#define DBTP_DTSEG2_MASK (0xf << DBTP_DTSEG2_SHIFT)
#define DBTP_DSJW_SHIFT 0
#define DBTP_DSJW_MASK (0xf << DBTP_DSJW_SHIFT)
/* Test Register (TEST) */
#define TEST_LBCK BIT(4)
/* CC Control Register(CCCR) */
#define CCCR_CMR_MASK 0x3
#define CCCR_CMR_SHIFT 10
#define CCCR_CMR_CANFD 0x1
#define CCCR_CMR_CANFD_BRS 0x2
#define CCCR_CMR_CAN 0x3
#define CCCR_CME_MASK 0x3
#define CCCR_CME_SHIFT 8
#define CCCR_CME_CAN 0
#define CCCR_CME_CANFD 0x1
#define CCCR_CME_CANFD_BRS 0x2
#define CCCR_TXP BIT(14)
#define CCCR_TEST BIT(7)
#define CCCR_MON BIT(5)
#define CCCR_CSR BIT(4)
#define CCCR_CSA BIT(3)
#define CCCR_ASM BIT(2)
#define CCCR_CCE BIT(1)
#define CCCR_INIT BIT(0)
#define CCCR_CANFD 0x10
/* for version >=3.1.x */
#define CCCR_EFBI BIT(13)
#define CCCR_PXHD BIT(12)
#define CCCR_BRSE BIT(9)
#define CCCR_FDOE BIT(8)
/* only for version >=3.2.x */
#define CCCR_NISO BIT(15)
/* Nominal Bit Timing & Prescaler Register (NBTP) */
#define NBTP_NSJW_SHIFT 25
#define NBTP_NSJW_MASK (0x7f << NBTP_NSJW_SHIFT)
#define NBTP_NBRP_SHIFT 16
#define NBTP_NBRP_MASK (0x1ff << NBTP_NBRP_SHIFT)
#define NBTP_NTSEG1_SHIFT 8
#define NBTP_NTSEG1_MASK (0xff << NBTP_NTSEG1_SHIFT)
#define NBTP_NTSEG2_SHIFT 0
#define NBTP_NTSEG2_MASK (0x7f << NBTP_NTSEG2_SHIFT)
/* 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
/* Renamed bits for versions > 3.1.x */
#define IR_ARA BIT(29)
#define IR_PED BIT(28)
#define IR_PEA BIT(27)
/* Bits for version 3.0.x */
#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)
/* Interrupts for version 3.0.x */
#define IR_ERR_LEC_30X (IR_STE | IR_FOE | IR_ACKE | IR_BE | IR_CRCE)
#define IR_ERR_BUS_30X (IR_ERR_LEC_30X | IR_WDI | IR_ELO | IR_BEU | \
IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | \
IR_RF1L | IR_RF0L)
#define IR_ERR_ALL_30X (IR_ERR_STATE | IR_ERR_BUS_30X)
/* Interrupts for version >= 3.1.x */
#define IR_ERR_LEC_31X (IR_PED | IR_PEA)
#define IR_ERR_BUS_31X (IR_ERR_LEC_31X | IR_WDI | IR_ELO | IR_BEU | \
IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | \
IR_RF1L | IR_RF0L)
#define IR_ERR_ALL_31X (IR_ERR_STATE | IR_ERR_BUS_31X)
/* Interrupt Line Select (ILS) */
#define ILS_ALL_INT0 0x0
#define ILS_ALL_INT1 0xFFFFFFFF
/* Interrupt Line Enable (ILE) */
#define ILE_EINT1 BIT(1)
#define ILE_EINT0 BIT(0)
/* Rx FIFO 0/1 Configuration (RXF0C/RXF1C) */
#define RXFC_FWM_SHIFT 24
#define RXFC_FWM_MASK (0x7f < RXFC_FWM_SHIFT)
#define RXFC_FS_SHIFT 16
#define RXFC_FS_MASK (0x7f << RXFC_FS_SHIFT)
/* Rx FIFO 0/1 Status (RXF0S/RXF1S) */
#define RXFS_RFL BIT(25)
#define RXFS_FF BIT(24)
#define RXFS_FPI_SHIFT 16
#define RXFS_FPI_MASK 0x3f0000
#define RXFS_FGI_SHIFT 8
#define RXFS_FGI_MASK 0x3f00
#define RXFS_FFL_MASK 0x7f
/* Rx Buffer / FIFO Element Size Configuration (RXESC) */
#define M_CAN_RXESC_8BYTES 0x0
#define M_CAN_RXESC_64BYTES 0x777
/* Tx Buffer Configuration(TXBC) */
#define TXBC_NDTB_SHIFT 16
#define TXBC_NDTB_MASK (0x3f << TXBC_NDTB_SHIFT)
#define TXBC_TFQS_SHIFT 24
#define TXBC_TFQS_MASK (0x3f << TXBC_TFQS_SHIFT)
/* Tx FIFO/Queue Status (TXFQS) */
#define TXFQS_TFQF BIT(21)
#define TXFQS_TFQPI_SHIFT 16
#define TXFQS_TFQPI_MASK (0x1f << TXFQS_TFQPI_SHIFT)
#define TXFQS_TFGI_SHIFT 8
#define TXFQS_TFGI_MASK (0x1f << TXFQS_TFGI_SHIFT)
#define TXFQS_TFFL_SHIFT 0
#define TXFQS_TFFL_MASK (0x3f << TXFQS_TFFL_SHIFT)
/* Tx Buffer Element Size Configuration(TXESC) */
#define TXESC_TBDS_8BYTES 0x0
#define TXESC_TBDS_64BYTES 0x7
/* Tx Event FIFO Configuration (TXEFC) */
#define TXEFC_EFS_SHIFT 16
#define TXEFC_EFS_MASK (0x3f << TXEFC_EFS_SHIFT)
/* Tx Event FIFO Status (TXEFS) */
#define TXEFS_TEFL BIT(25)
#define TXEFS_EFF BIT(24)
#define TXEFS_EFGI_SHIFT 8
#define TXEFS_EFGI_MASK (0x1f << TXEFS_EFGI_SHIFT)
#define TXEFS_EFFL_SHIFT 0
#define TXEFS_EFFL_MASK (0x3f << TXEFS_EFFL_SHIFT)
/* Tx Event FIFO Acknowledge (TXEFA) */
#define TXEFA_EFAI_SHIFT 0
#define TXEFA_EFAI_MASK (0x1f << TXEFA_EFAI_SHIFT)
/* Message RAM Configuration (in bytes) */
#define SIDF_ELEMENT_SIZE 4
#define XIDF_ELEMENT_SIZE 8
#define RXF0_ELEMENT_SIZE 72
#define RXF1_ELEMENT_SIZE 72
#define RXB_ELEMENT_SIZE 72
#define TXE_ELEMENT_SIZE 8
#define TXB_ELEMENT_SIZE 72
/* 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 */
/* R0 */
#define RX_BUF_ESI BIT(31)
#define RX_BUF_XTD BIT(30)
#define RX_BUF_RTR BIT(29)
/* R1 */
#define RX_BUF_ANMF BIT(31)
#define RX_BUF_FDF BIT(21)
#define RX_BUF_BRS BIT(20)
/* Tx Buffer Element */
/* T0 */
#define TX_BUF_ESI BIT(31)
#define TX_BUF_XTD BIT(30)
#define TX_BUF_RTR BIT(29)
/* T1 */
#define TX_BUF_EFC BIT(23)
#define TX_BUF_FDF BIT(21)
#define TX_BUF_BRS BIT(20)
#define TX_BUF_MM_SHIFT 24
#define TX_BUF_MM_MASK (0xff << TX_BUF_MM_SHIFT)
/* Tx event FIFO Element */
/* E1 */
#define TX_EVENT_MM_SHIFT TX_BUF_MM_SHIFT
#define TX_EVENT_MM_MASK (0xff << TX_EVENT_MM_SHIFT)
/* 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;
int version;
/* 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)
{
writel(val, priv->mram_base + priv->mcfg[MRAM_TXB].off +
fpi * TXB_ELEMENT_SIZE + offset);
}
static inline u32 m_can_txe_fifo_read(const struct m_can_priv *priv,
u32 fgi,
u32 offset) {
return readl(priv->mram_base + priv->mcfg[MRAM_TXE].off +
fgi * TXE_ELEMENT_SIZE + offset);
}
static inline bool m_can_tx_fifo_full(const struct m_can_priv *priv)
{
return !!(m_can_read(priv, M_CAN_TXFQS) & TXFQS_TFQF);
}
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)
{
/* Only interrupt line 0 is used in this driver */
m_can_write(priv, M_CAN_ILE, ILE_EINT0);
}
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(struct net_device *dev, u32 rxfs)
{
struct net_device_stats *stats = &dev->stats;
struct m_can_priv *priv = netdev_priv(dev);
struct canfd_frame *cf;
struct sk_buff *skb;
u32 id, fgi, dlc;
int i;
/* calculate the fifo get index for where to read data */
fgi = (rxfs & RXFS_FGI_MASK) >> RXFS_FGI_SHIFT;
dlc = m_can_fifo_read(priv, fgi, M_CAN_FIFO_DLC);
if (dlc & RX_BUF_FDF)
skb = alloc_canfd_skb(dev, &cf);
else
skb = alloc_can_skb(dev, (struct can_frame **)&cf);
if (!skb) {
stats->rx_dropped++;
return;
}
if (dlc & RX_BUF_FDF)
cf->len = can_dlc2len((dlc >> 16) & 0x0F);
else
cf->len = get_can_dlc((dlc >> 16) & 0x0F);
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;
if (id & RX_BUF_ESI) {
cf->flags |= CANFD_ESI;
netdev_dbg(dev, "ESI Error\n");
}
if (!(dlc & RX_BUF_FDF) && (id & RX_BUF_RTR)) {
cf->can_id |= CAN_RTR_FLAG;
} else {
if (dlc & RX_BUF_BRS)
cf->flags |= CANFD_BRS;
for (i = 0; i < cf->len; i += 4)
*(u32 *)(cf->data + i) =
m_can_fifo_read(priv, fgi,
M_CAN_FIFO_DATA(i / 4));
}
/* acknowledge rx fifo 0 */
m_can_write(priv, M_CAN_RXF0A, fgi);
stats->rx_packets++;
stats->rx_bytes += cf->len;
netif_receive_skb(skb);
}
static int m_can_do_rx_poll(struct net_device *dev, int quota)
{
struct m_can_priv *priv = netdev_priv(dev);
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");
m_can_read_fifo(dev, rxfs);
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;
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;
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;
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) >> ECR_TEC_SHIFT;
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);
priv->can.can_stats.bus_off++;
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 passive 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 bus off 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_ELO)
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_30X)
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_done(napi, work_done);
m_can_enable_all_interrupts(priv);
}
end:
return work_done;
}
static void m_can_echo_tx_event(struct net_device *dev)
{
u32 txe_count = 0;
u32 m_can_txefs;
u32 fgi = 0;
int i = 0;
unsigned int msg_mark;
struct m_can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
/* read tx event fifo status */
m_can_txefs = m_can_read(priv, M_CAN_TXEFS);
/* Get Tx Event fifo element count */
txe_count = (m_can_txefs & TXEFS_EFFL_MASK)
>> TXEFS_EFFL_SHIFT;
/* Get and process all sent elements */
for (i = 0; i < txe_count; i++) {
/* retrieve get index */
fgi = (m_can_read(priv, M_CAN_TXEFS) & TXEFS_EFGI_MASK)
>> TXEFS_EFGI_SHIFT;
/* get message marker */
msg_mark = (m_can_txe_fifo_read(priv, fgi, 4) &
TX_EVENT_MM_MASK) >> TX_EVENT_MM_SHIFT;
/* ack txe element */
m_can_write(priv, M_CAN_TXEFA, (TXEFA_EFAI_MASK &
(fgi << TXEFA_EFAI_SHIFT)));
/* update stats */
stats->tx_bytes += can_get_echo_skb(dev, msg_mark);
stats->tx_packets++;
}
}
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_30X)) {
priv->irqstatus = ir;
m_can_disable_all_interrupts(priv);
napi_schedule(&priv->napi);
}
if (priv->version == 30) {
if (ir & IR_TC) {
/* Transmission Complete Interrupt*/
stats->tx_bytes += can_get_echo_skb(dev, 0);
stats->tx_packets++;
can_led_event(dev, CAN_LED_EVENT_TX);
netif_wake_queue(dev);
}
} else {
if (ir & IR_TEFN) {
/* New TX FIFO Element arrived */
m_can_echo_tx_event(dev);
can_led_event(dev, CAN_LED_EVENT_TX);
if (netif_queue_stopped(dev) &&
!m_can_tx_fifo_full(priv))
netif_wake_queue(dev);
}
}
return IRQ_HANDLED;
}
static const struct can_bittiming_const m_can_bittiming_const_30X = {
.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 const struct can_bittiming_const m_can_data_bittiming_const_30X = {
.name = KBUILD_MODNAME,
.tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */
.tseg1_max = 16,
.tseg2_min = 1, /* Time segment 2 = phase_seg2 */
.tseg2_max = 8,
.sjw_max = 4,
.brp_min = 1,
.brp_max = 32,
.brp_inc = 1,
};
static const struct can_bittiming_const m_can_bittiming_const_31X = {
.name = KBUILD_MODNAME,
.tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */
.tseg1_max = 256,
.tseg2_min = 1, /* Time segment 2 = phase_seg2 */
.tseg2_max = 128,
.sjw_max = 128,
.brp_min = 1,
.brp_max = 512,
.brp_inc = 1,
};
static const struct can_bittiming_const m_can_data_bittiming_const_31X = {
.name = KBUILD_MODNAME,
.tseg1_min = 1, /* Time segment 1 = prop_seg + phase_seg1 */
.tseg1_max = 32,
.tseg2_min = 1, /* Time segment 2 = phase_seg2 */
.tseg2_max = 16,
.sjw_max = 16,
.brp_min = 1,
.brp_max = 32,
.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;
const struct can_bittiming *dbt = &priv->can.data_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 << NBTP_NBRP_SHIFT) | (sjw << NBTP_NSJW_SHIFT) |
(tseg1 << NBTP_NTSEG1_SHIFT) | (tseg2 << NBTP_NTSEG2_SHIFT);
m_can_write(priv, M_CAN_NBTP, reg_btp);
if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
brp = dbt->brp - 1;
sjw = dbt->sjw - 1;
tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
tseg2 = dbt->phase_seg2 - 1;
reg_btp = (brp << DBTP_DBRP_SHIFT) | (sjw << DBTP_DSJW_SHIFT) |
(tseg1 << DBTP_DTSEG1_SHIFT) |
(tseg2 << DBTP_DTSEG2_SHIFT);
m_can_write(priv, M_CAN_DBTP, 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
* - >= v3.1.x: TX FIFO is used
* - 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 64 bytes data field */
m_can_write(priv, M_CAN_RXESC, M_CAN_RXESC_64BYTES);
/* Accept Non-matching Frames Into FIFO 0 */
m_can_write(priv, M_CAN_GFC, 0x0);
if (priv->version == 30) {
/* only support one Tx Buffer currently */
m_can_write(priv, M_CAN_TXBC, (1 << TXBC_NDTB_SHIFT) |
priv->mcfg[MRAM_TXB].off);
} else {
/* TX FIFO is used for newer IP Core versions */
m_can_write(priv, M_CAN_TXBC,
(priv->mcfg[MRAM_TXB].num << TXBC_TFQS_SHIFT) |
(priv->mcfg[MRAM_TXB].off));
}
/* support 64 bytes payload */
m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_64BYTES);
/* TX Event FIFO */
if (priv->version == 30) {
m_can_write(priv, M_CAN_TXEFC, (1 << TXEFC_EFS_SHIFT) |
priv->mcfg[MRAM_TXE].off);
} else {
/* Full TX Event FIFO is used */
m_can_write(priv, M_CAN_TXEFC,
((priv->mcfg[MRAM_TXE].num << TXEFC_EFS_SHIFT)
& TXEFC_EFS_MASK) |
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_SHIFT) |
priv->mcfg[MRAM_RXF0].off);
m_can_write(priv, M_CAN_RXF1C,
(priv->mcfg[MRAM_RXF1].num << RXFC_FS_SHIFT) |
priv->mcfg[MRAM_RXF1].off);
cccr = m_can_read(priv, M_CAN_CCCR);
test = m_can_read(priv, M_CAN_TEST);
test &= ~TEST_LBCK;
if (priv->version == 30) {
/* Version 3.0.x */
cccr &= ~(CCCR_TEST | CCCR_MON |
(CCCR_CMR_MASK << CCCR_CMR_SHIFT) |
(CCCR_CME_MASK << CCCR_CME_SHIFT));
if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
cccr |= CCCR_CME_CANFD_BRS << CCCR_CME_SHIFT;
} else {
/* Version 3.1.x or 3.2.x */
cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_BRSE | CCCR_FDOE);
/* Only 3.2.x has NISO Bit implemented */
if (priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
cccr |= CCCR_NISO;
if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
cccr |= (CCCR_BRSE | CCCR_FDOE);
}
/* Loopback Mode */
if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
cccr |= CCCR_TEST | CCCR_MON;
test |= TEST_LBCK;
}
/* Enable Monitoring (all versions) */
if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
cccr |= CCCR_MON;
/* Write config */
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))
if (priv->version == 30)
m_can_write(priv, M_CAN_IE, IR_ALL_INT &
~(IR_ERR_LEC_30X));
else
m_can_write(priv, M_CAN_IE, IR_ALL_INT &
~(IR_ERR_LEC_31X));
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);
}
/* Checks core release number of M_CAN
* returns 0 if an unsupported device is detected
* else it returns the release and step coded as:
* return value = 10 * <release> + 1 * <step>
*/
static int m_can_check_core_release(void * __iomem m_can_base)
{
u32 crel_reg;
u8 rel;
u8 step;
int res;
struct m_can_priv temp_priv = {
.base = m_can_base
};
/* Read Core Release Version and split into version number
* Example: Version 3.2.1 => rel = 3; step = 2; substep = 1;
*/
crel_reg = m_can_read(&temp_priv, M_CAN_CREL);
rel = (u8)((crel_reg & CREL_REL_MASK) >> CREL_REL_SHIFT);
step = (u8)((crel_reg & CREL_STEP_MASK) >> CREL_STEP_SHIFT);
if (rel == 3) {
/* M_CAN v3.x.y: create return value */
res = 30 + step;
} else {
/* Unsupported M_CAN version */
res = 0;
}
return res;
}
/* Selectable Non ISO support only in version 3.2.x
* This function checks if the bit is writable.
*/
static bool m_can_niso_supported(const struct m_can_priv *priv)
{
u32 cccr_reg, cccr_poll;
int niso_timeout;
m_can_config_endisable(priv, true);
cccr_reg = m_can_read(priv, M_CAN_CCCR);
cccr_reg |= CCCR_NISO;
m_can_write(priv, M_CAN_CCCR, cccr_reg);
niso_timeout = readl_poll_timeout((priv->base + M_CAN_CCCR), cccr_poll,
(cccr_poll == cccr_reg), 0, 10);
/* Clear NISO */
cccr_reg &= ~(CCCR_NISO);
m_can_write(priv, M_CAN_CCCR, cccr_reg);
m_can_config_endisable(priv, false);
/* return false if time out (-ETIMEDOUT), else return true */
return !niso_timeout;
}
static struct net_device *alloc_m_can_dev(struct platform_device *pdev,
void __iomem *addr, u32 tx_fifo_size)
{
struct net_device *dev;
struct m_can_priv *priv;
int m_can_version;
unsigned int echo_buffer_count;
m_can_version = m_can_check_core_release(addr);
/* return if unsupported version */
if (!m_can_version) {
dev = NULL;
goto return_dev;
}
/* If version < 3.1.x, then only one echo buffer is used */
echo_buffer_count = ((m_can_version == 30)
? 1U
: (unsigned int)tx_fifo_size);
dev = alloc_candev(sizeof(*priv), echo_buffer_count);
if (!dev) {
dev = NULL;
goto return_dev;
}
priv = netdev_priv(dev);
netif_napi_add(dev, &priv->napi, m_can_poll, M_CAN_NAPI_WEIGHT);
/* Shared properties of all M_CAN versions */
priv->version = m_can_version;
priv->dev = dev;
priv->base = addr;
priv->can.do_set_mode = m_can_set_mode;
priv->can.do_get_berr_counter = m_can_get_berr_counter;
/* Set M_CAN supported operations */
priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
CAN_CTRLMODE_LISTENONLY |
CAN_CTRLMODE_BERR_REPORTING |
CAN_CTRLMODE_FD;
/* Set properties depending on M_CAN version */
switch (priv->version) {
case 30:
/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */
can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
priv->can.bittiming_const = &m_can_bittiming_const_30X;
priv->can.data_bittiming_const =
&m_can_data_bittiming_const_30X;
break;
case 31:
/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */
can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
priv->can.bittiming_const = &m_can_bittiming_const_31X;
priv->can.data_bittiming_const =
&m_can_data_bittiming_const_31X;
break;
case 32:
priv->can.bittiming_const = &m_can_bittiming_const_31X;
priv->can.data_bittiming_const =
&m_can_data_bittiming_const_31X;
priv->can.ctrlmode_supported |= (m_can_niso_supported(priv)
? CAN_CTRLMODE_FD_NON_ISO
: 0);
break;
default:
/* Unsupported device: free candev */
free_m_can_dev(dev);
dev_err(&pdev->dev, "Unsupported version number: %2d",
priv->version);
dev = NULL;
break;
}
return_dev:
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 int m_can_next_echo_skb_occupied(struct net_device *dev, int putidx)
{
struct m_can_priv *priv = netdev_priv(dev);
/*get wrap around for loopback skb index */
unsigned int wrap = priv->can.echo_skb_max;
int next_idx;
/* calculate next index */
next_idx = (++putidx >= wrap ? 0 : putidx);
/* check if occupied */
return !!priv->can.echo_skb[next_idx];
}
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 canfd_frame *cf = (struct canfd_frame *)skb->data;
u32 id, cccr, fdflags;
int i;
int putidx;
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
/* Generate ID field for TX buffer Element */
/* Common to all supported M_CAN versions */
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;
if (priv->version == 30) {
netif_stop_queue(dev);
/* message ram configuration */
m_can_fifo_write(priv, 0, M_CAN_FIFO_ID, id);
m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC,
can_len2dlc(cf->len) << 16);
for (i = 0; i < cf->len; i += 4)
m_can_fifo_write(priv, 0,
M_CAN_FIFO_DATA(i / 4),
*(u32 *)(cf->data + i));
can_put_echo_skb(skb, dev, 0);
if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
cccr = m_can_read(priv, M_CAN_CCCR);
cccr &= ~(CCCR_CMR_MASK << CCCR_CMR_SHIFT);
if (can_is_canfd_skb(skb)) {
if (cf->flags & CANFD_BRS)
cccr |= CCCR_CMR_CANFD_BRS <<
CCCR_CMR_SHIFT;
else
cccr |= CCCR_CMR_CANFD <<
CCCR_CMR_SHIFT;
} else {
cccr |= CCCR_CMR_CAN << CCCR_CMR_SHIFT;
}
m_can_write(priv, M_CAN_CCCR, cccr);
}
m_can_write(priv, M_CAN_TXBTIE, 0x1);
m_can_write(priv, M_CAN_TXBAR, 0x1);
/* End of xmit function for version 3.0.x */
} else {
/* Transmit routine for version >= v3.1.x */
/* Check if FIFO full */
if (m_can_tx_fifo_full(priv)) {
/* This shouldn't happen */
netif_stop_queue(dev);
netdev_warn(dev,
"TX queue active although FIFO is full.");
return NETDEV_TX_BUSY;
}
/* get put index for frame */
putidx = ((m_can_read(priv, M_CAN_TXFQS) & TXFQS_TFQPI_MASK)
>> TXFQS_TFQPI_SHIFT);
/* Write ID Field to FIFO Element */
m_can_fifo_write(priv, putidx, M_CAN_FIFO_ID, id);
/* get CAN FD configuration of frame */
fdflags = 0;
if (can_is_canfd_skb(skb)) {
fdflags |= TX_BUF_FDF;
if (cf->flags & CANFD_BRS)
fdflags |= TX_BUF_BRS;
}
/* Construct DLC Field. Also contains CAN-FD configuration
* use put index of fifo as message marker
* it is used in TX interrupt for
* sending the correct echo frame
*/
m_can_fifo_write(priv, putidx, M_CAN_FIFO_DLC,
((putidx << TX_BUF_MM_SHIFT) &
TX_BUF_MM_MASK) |
(can_len2dlc(cf->len) << 16) |
fdflags | TX_BUF_EFC);
for (i = 0; i < cf->len; i += 4)
m_can_fifo_write(priv, putidx, M_CAN_FIFO_DATA(i / 4),
*(u32 *)(cf->data + i));
/* Push loopback echo.
* Will be looped back on TX interrupt based on message marker
*/
can_put_echo_skb(skb, dev, putidx);
/* Enable TX FIFO element to start transfer */
m_can_write(priv, M_CAN_TXBAR, (1 << putidx));
/* stop network queue if fifo full */
if (m_can_tx_fifo_full(priv) ||
m_can_next_echo_skb_occupied(dev, putidx))
netif_stop_queue(dev);
}
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 void m_can_of_parse_mram(struct m_can_priv *priv,
const u32 *mram_config_vals)
{
int i, start, end;
priv->mcfg[MRAM_SIDF].off = mram_config_vals[0];
priv->mcfg[MRAM_SIDF].num = mram_config_vals[1];
priv->mcfg[MRAM_XIDF].off = priv->mcfg[MRAM_SIDF].off +
priv->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE;
priv->mcfg[MRAM_XIDF].num = mram_config_vals[2];
priv->mcfg[MRAM_RXF0].off = priv->mcfg[MRAM_XIDF].off +
priv->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE;
priv->mcfg[MRAM_RXF0].num = mram_config_vals[3] &
(RXFC_FS_MASK >> RXFC_FS_SHIFT);
priv->mcfg[MRAM_RXF1].off = priv->mcfg[MRAM_RXF0].off +
priv->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE;
priv->mcfg[MRAM_RXF1].num = mram_config_vals[4] &
(RXFC_FS_MASK >> RXFC_FS_SHIFT);
priv->mcfg[MRAM_RXB].off = priv->mcfg[MRAM_RXF1].off +
priv->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE;
priv->mcfg[MRAM_RXB].num = mram_config_vals[5];
priv->mcfg[MRAM_TXE].off = priv->mcfg[MRAM_RXB].off +
priv->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE;
priv->mcfg[MRAM_TXE].num = mram_config_vals[6];
priv->mcfg[MRAM_TXB].off = priv->mcfg[MRAM_TXE].off +
priv->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE;
priv->mcfg[MRAM_TXB].num = mram_config_vals[7] &
(TXBC_NDTB_MASK >> TXBC_NDTB_SHIFT);
dev_dbg(priv->device,
"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);
}
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;
void __iomem *mram_addr;
struct clk *hclk, *cclk;
int irq, ret;
struct device_node *np;
u32 mram_config_vals[MRAM_CFG_LEN];
u32 tx_fifo_size;
np = pdev->dev.of_node;
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 found\n");
ret = -ENODEV;
goto failed_ret;
}
/* Enable clocks. Necessary to read Core Release in order to determine
* M_CAN version
*/
ret = clk_prepare_enable(hclk);
if (ret)
goto disable_hclk_ret;
ret = clk_prepare_enable(cclk);
if (ret)
goto disable_cclk_ret;
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) {
ret = -EINVAL;
goto disable_cclk_ret;
}
/* message ram could be shared */
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
if (!res) {
ret = -ENODEV;
goto disable_cclk_ret;
}
mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
if (!mram_addr) {
ret = -ENOMEM;
goto disable_cclk_ret;
}
/* get message ram configuration */
ret = of_property_read_u32_array(np, "bosch,mram-cfg",
mram_config_vals,
sizeof(mram_config_vals) / 4);
if (ret) {
dev_err(&pdev->dev, "Could not get Message RAM configuration.");
goto disable_cclk_ret;
}
/* Get TX FIFO size
* Defines the total amount of echo buffers for loopback
*/
tx_fifo_size = mram_config_vals[7];
/* allocate the m_can device */
dev = alloc_m_can_dev(pdev, addr, tx_fifo_size);
if (!dev) {
ret = -ENOMEM;
goto disable_cclk_ret;
}
priv = netdev_priv(dev);
dev->irq = irq;
priv->device = &pdev->dev;
priv->hclk = hclk;
priv->cclk = cclk;
priv->can.clock.freq = clk_get_rate(cclk);
priv->mram_base = mram_addr;
m_can_of_parse_mram(priv, mram_config_vals);
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 (irq=%d, version=%d)\n",
KBUILD_MODNAME, dev->irq, priv->version);
/* Probe finished
* Stop clocks. They will be reactivated once the M_CAN device is opened
*/
goto disable_cclk_ret;
failed_free_dev:
free_m_can_dev(dev);
disable_cclk_ret:
clk_disable_unprepare(cclk);
disable_hclk_ret:
clk_disable_unprepare(hclk);
failed_ret:
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");
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