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linux-zen-server/drivers/net/can/m_can/m_can.c

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Initial commit
2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0
// CAN bus driver for Bosch M_CAN controller
// Copyright (C) 2014 Freescale Semiconductor, Inc.
// Dong Aisheng <b29396@freescale.com>
// Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
/* Bosch M_CAN user manual can be obtained from:
* https://github.com/linux-can/can-doc/tree/master/m_can
*/
#include <linux/bitfield.h>
#include <linux/can/dev.h>
#include <linux/ethtool.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/phy/phy.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include "m_can.h"
/* 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,
};
/* message ram configuration data length */
#define MRAM_CFG_LEN 8
/* Core Release Register (CREL) */
#define CREL_REL_MASK GENMASK(31, 28)
#define CREL_STEP_MASK GENMASK(27, 24)
#define CREL_SUBSTEP_MASK GENMASK(23, 20)
/* Data Bit Timing & Prescaler Register (DBTP) */
#define DBTP_TDC BIT(23)
#define DBTP_DBRP_MASK GENMASK(20, 16)
#define DBTP_DTSEG1_MASK GENMASK(12, 8)
#define DBTP_DTSEG2_MASK GENMASK(7, 4)
#define DBTP_DSJW_MASK GENMASK(3, 0)
/* Transmitter Delay Compensation Register (TDCR) */
#define TDCR_TDCO_MASK GENMASK(14, 8)
#define TDCR_TDCF_MASK GENMASK(6, 0)
/* Test Register (TEST) */
#define TEST_LBCK BIT(4)
/* CC Control Register (CCCR) */
#define CCCR_TXP BIT(14)
#define CCCR_TEST BIT(7)
#define CCCR_DAR BIT(6)
#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)
/* for version 3.0.x */
#define CCCR_CMR_MASK GENMASK(11, 10)
#define CCCR_CMR_CANFD 0x1
#define CCCR_CMR_CANFD_BRS 0x2
#define CCCR_CMR_CAN 0x3
#define CCCR_CME_MASK GENMASK(9, 8)
#define CCCR_CME_CAN 0
#define CCCR_CME_CANFD 0x1
#define CCCR_CME_CANFD_BRS 0x2
/* 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)
/* for version >=3.2.x */
#define CCCR_NISO BIT(15)
/* for version >=3.3.x */
#define CCCR_WMM BIT(11)
#define CCCR_UTSU BIT(10)
/* Nominal Bit Timing & Prescaler Register (NBTP) */
#define NBTP_NSJW_MASK GENMASK(31, 25)
#define NBTP_NBRP_MASK GENMASK(24, 16)
#define NBTP_NTSEG1_MASK GENMASK(15, 8)
#define NBTP_NTSEG2_MASK GENMASK(6, 0)
/* Timestamp Counter Configuration Register (TSCC) */
#define TSCC_TCP_MASK GENMASK(19, 16)
#define TSCC_TSS_MASK GENMASK(1, 0)
#define TSCC_TSS_DISABLE 0x0
#define TSCC_TSS_INTERNAL 0x1
#define TSCC_TSS_EXTERNAL 0x2
/* Timestamp Counter Value Register (TSCV) */
#define TSCV_TSC_MASK GENMASK(15, 0)
/* Error Counter Register (ECR) */
#define ECR_RP BIT(15)
#define ECR_REC_MASK GENMASK(14, 8)
#define ECR_TEC_MASK GENMASK(7, 0)
/* Protocol Status Register (PSR) */
#define PSR_BO BIT(7)
#define PSR_EW BIT(6)
#define PSR_EP BIT(5)
#define PSR_LEC_MASK GENMASK(2, 0)
#define PSR_DLEC_MASK GENMASK(10, 8)
/* 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_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_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_MASK GENMASK(30, 24)
#define RXFC_FS_MASK GENMASK(22, 16)
/* Rx FIFO 0/1 Status (RXF0S/RXF1S) */
#define RXFS_RFL BIT(25)
#define RXFS_FF BIT(24)
#define RXFS_FPI_MASK GENMASK(21, 16)
#define RXFS_FGI_MASK GENMASK(13, 8)
#define RXFS_FFL_MASK GENMASK(6, 0)
/* Rx Buffer / FIFO Element Size Configuration (RXESC) */
#define RXESC_RBDS_MASK GENMASK(10, 8)
#define RXESC_F1DS_MASK GENMASK(6, 4)
#define RXESC_F0DS_MASK GENMASK(2, 0)
#define RXESC_64B 0x7
/* Tx Buffer Configuration (TXBC) */
#define TXBC_TFQS_MASK GENMASK(29, 24)
#define TXBC_NDTB_MASK GENMASK(21, 16)
/* Tx FIFO/Queue Status (TXFQS) */
#define TXFQS_TFQF BIT(21)
#define TXFQS_TFQPI_MASK GENMASK(20, 16)
#define TXFQS_TFGI_MASK GENMASK(12, 8)
#define TXFQS_TFFL_MASK GENMASK(5, 0)
/* Tx Buffer Element Size Configuration (TXESC) */
#define TXESC_TBDS_MASK GENMASK(2, 0)
#define TXESC_TBDS_64B 0x7
/* Tx Event FIFO Configuration (TXEFC) */
#define TXEFC_EFS_MASK GENMASK(21, 16)
/* Tx Event FIFO Status (TXEFS) */
#define TXEFS_TEFL BIT(25)
#define TXEFS_EFF BIT(24)
#define TXEFS_EFGI_MASK GENMASK(12, 8)
#define TXEFS_EFFL_MASK GENMASK(5, 0)
/* Tx Event FIFO Acknowledge (TXEFA) */
#define TXEFA_EFAI_MASK GENMASK(4, 0)
/* 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 0x8
/* 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)
#define RX_BUF_RXTS_MASK GENMASK(15, 0)
/* 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_MASK GENMASK(31, 24)
#define TX_BUF_DLC_MASK GENMASK(19, 16)
/* Tx event FIFO Element */
/* E1 */
#define TX_EVENT_MM_MASK GENMASK(31, 24)
#define TX_EVENT_TXTS_MASK GENMASK(15, 0)
/* The ID and DLC registers are adjacent in M_CAN FIFO memory,
* and we can save a (potentially slow) bus round trip by combining
* reads and writes to them.
*/
struct id_and_dlc {
u32 id;
u32 dlc;
};
static inline u32 m_can_read(struct m_can_classdev *cdev, enum m_can_reg reg)
{
return cdev->ops->read_reg(cdev, reg);
}
static inline void m_can_write(struct m_can_classdev *cdev, enum m_can_reg reg,
u32 val)
{
cdev->ops->write_reg(cdev, reg, val);
}
static int
m_can_fifo_read(struct m_can_classdev *cdev,
u32 fgi, unsigned int offset, void *val, size_t val_count)
{
u32 addr_offset = cdev->mcfg[MRAM_RXF0].off + fgi * RXF0_ELEMENT_SIZE +
offset;
if (val_count == 0)
return 0;
return cdev->ops->read_fifo(cdev, addr_offset, val, val_count);
}
static int
m_can_fifo_write(struct m_can_classdev *cdev,
u32 fpi, unsigned int offset, const void *val, size_t val_count)
{
u32 addr_offset = cdev->mcfg[MRAM_TXB].off + fpi * TXB_ELEMENT_SIZE +
offset;
if (val_count == 0)
return 0;
return cdev->ops->write_fifo(cdev, addr_offset, val, val_count);
}
static inline int m_can_fifo_write_no_off(struct m_can_classdev *cdev,
u32 fpi, u32 val)
{
return cdev->ops->write_fifo(cdev, fpi, &val, 1);
}
static int
m_can_txe_fifo_read(struct m_can_classdev *cdev, u32 fgi, u32 offset, u32 *val)
{
u32 addr_offset = cdev->mcfg[MRAM_TXE].off + fgi * TXE_ELEMENT_SIZE +
offset;
return cdev->ops->read_fifo(cdev, addr_offset, val, 1);
}
static inline bool _m_can_tx_fifo_full(u32 txfqs)
{
return !!(txfqs & TXFQS_TFQF);
}
static inline bool m_can_tx_fifo_full(struct m_can_classdev *cdev)
{
return _m_can_tx_fifo_full(m_can_read(cdev, M_CAN_TXFQS));
}
static void m_can_config_endisable(struct m_can_classdev *cdev, bool enable)
{
u32 cccr = m_can_read(cdev, M_CAN_CCCR);
u32 timeout = 10;
u32 val = 0;
/* Clear the Clock stop request if it was set */
if (cccr & CCCR_CSR)
cccr &= ~CCCR_CSR;
if (enable) {
/* enable m_can configuration */
m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT);
udelay(5);
/* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */
m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE);
} else {
m_can_write(cdev, 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(cdev, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) {
if (timeout == 0) {
netdev_warn(cdev->net, "Failed to init module\n");
return;
}
timeout--;
udelay(1);
}
}
static inline void m_can_enable_all_interrupts(struct m_can_classdev *cdev)
{
/* Only interrupt line 0 is used in this driver */
m_can_write(cdev, M_CAN_ILE, ILE_EINT0);
}
static inline void m_can_disable_all_interrupts(struct m_can_classdev *cdev)
{
m_can_write(cdev, M_CAN_ILE, 0x0);
}
/* Retrieve internal timestamp counter from TSCV.TSC, and shift it to 32-bit
* width.
*/
static u32 m_can_get_timestamp(struct m_can_classdev *cdev)
{
u32 tscv;
u32 tsc;
tscv = m_can_read(cdev, M_CAN_TSCV);
tsc = FIELD_GET(TSCV_TSC_MASK, tscv);
return (tsc << 16);
}
static void m_can_clean(struct net_device *net)
{
struct m_can_classdev *cdev = netdev_priv(net);
if (cdev->tx_skb) {
int putidx = 0;
net->stats.tx_errors++;
if (cdev->version > 30)
putidx = FIELD_GET(TXFQS_TFQPI_MASK,
m_can_read(cdev, M_CAN_TXFQS));
can_free_echo_skb(cdev->net, putidx, NULL);
cdev->tx_skb = NULL;
}
}
/* For peripherals, pass skb to rx-offload, which will push skb from
* napi. For non-peripherals, RX is done in napi already, so push
* directly. timestamp is used to ensure good skb ordering in
* rx-offload and is ignored for non-peripherals.
*/
static void m_can_receive_skb(struct m_can_classdev *cdev,
struct sk_buff *skb,
u32 timestamp)
{
if (cdev->is_peripheral) {
struct net_device_stats *stats = &cdev->net->stats;
int err;
err = can_rx_offload_queue_timestamp(&cdev->offload, skb,
timestamp);
if (err)
stats->rx_fifo_errors++;
} else {
netif_receive_skb(skb);
}
}
static int m_can_read_fifo(struct net_device *dev, u32 fgi)
{
struct net_device_stats *stats = &dev->stats;
struct m_can_classdev *cdev = netdev_priv(dev);
struct canfd_frame *cf;
struct sk_buff *skb;
struct id_and_dlc fifo_header;
u32 timestamp = 0;
int err;
err = m_can_fifo_read(cdev, fgi, M_CAN_FIFO_ID, &fifo_header, 2);
if (err)
goto out_fail;
if (fifo_header.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 0;
}
if (fifo_header.dlc & RX_BUF_FDF)
cf->len = can_fd_dlc2len((fifo_header.dlc >> 16) & 0x0F);
else
cf->len = can_cc_dlc2len((fifo_header.dlc >> 16) & 0x0F);
if (fifo_header.id & RX_BUF_XTD)
cf->can_id = (fifo_header.id & CAN_EFF_MASK) | CAN_EFF_FLAG;
else
cf->can_id = (fifo_header.id >> 18) & CAN_SFF_MASK;
if (fifo_header.id & RX_BUF_ESI) {
cf->flags |= CANFD_ESI;
netdev_dbg(dev, "ESI Error\n");
}
if (!(fifo_header.dlc & RX_BUF_FDF) && (fifo_header.id & RX_BUF_RTR)) {
cf->can_id |= CAN_RTR_FLAG;
} else {
if (fifo_header.dlc & RX_BUF_BRS)
cf->flags |= CANFD_BRS;
err = m_can_fifo_read(cdev, fgi, M_CAN_FIFO_DATA,
cf->data, DIV_ROUND_UP(cf->len, 4));
if (err)
goto out_free_skb;
stats->rx_bytes += cf->len;
}
stats->rx_packets++;
timestamp = FIELD_GET(RX_BUF_RXTS_MASK, fifo_header.dlc) << 16;
m_can_receive_skb(cdev, skb, timestamp);
return 0;
out_free_skb:
kfree_skb(skb);
out_fail:
netdev_err(dev, "FIFO read returned %d\n", err);
return err;
}
static int m_can_do_rx_poll(struct net_device *dev, int quota)
{
struct m_can_classdev *cdev = netdev_priv(dev);
u32 pkts = 0;
u32 rxfs;
u32 rx_count;
u32 fgi;
int ack_fgi = -1;
int i;
int err = 0;
rxfs = m_can_read(cdev, M_CAN_RXF0S);
if (!(rxfs & RXFS_FFL_MASK)) {
netdev_dbg(dev, "no messages in fifo0\n");
return 0;
}
rx_count = FIELD_GET(RXFS_FFL_MASK, rxfs);
fgi = FIELD_GET(RXFS_FGI_MASK, rxfs);
for (i = 0; i < rx_count && quota > 0; ++i) {
err = m_can_read_fifo(dev, fgi);
if (err)
break;
quota--;
pkts++;
ack_fgi = fgi;
fgi = (++fgi >= cdev->mcfg[MRAM_RXF0].num ? 0 : fgi);
}
if (ack_fgi != -1)
m_can_write(cdev, M_CAN_RXF0A, ack_fgi);
if (err)
return err;
return pkts;
}
static int m_can_handle_lost_msg(struct net_device *dev)
{
struct m_can_classdev *cdev = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
struct sk_buff *skb;
struct can_frame *frame;
u32 timestamp = 0;
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;
if (cdev->is_peripheral)
timestamp = m_can_get_timestamp(cdev);
m_can_receive_skb(cdev, skb, timestamp);
return 1;
}
static int m_can_handle_lec_err(struct net_device *dev,
enum m_can_lec_type lec_type)
{
struct m_can_classdev *cdev = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
struct can_frame *cf;
struct sk_buff *skb;
u32 timestamp = 0;
cdev->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;
}
if (cdev->is_peripheral)
timestamp = m_can_get_timestamp(cdev);
m_can_receive_skb(cdev, skb, timestamp);
return 1;
}
static int __m_can_get_berr_counter(const struct net_device *dev,
struct can_berr_counter *bec)
{
struct m_can_classdev *cdev = netdev_priv(dev);
unsigned int ecr;
ecr = m_can_read(cdev, M_CAN_ECR);
bec->rxerr = FIELD_GET(ECR_REC_MASK, ecr);
bec->txerr = FIELD_GET(ECR_TEC_MASK, ecr);
return 0;
}
static int m_can_clk_start(struct m_can_classdev *cdev)
{
if (cdev->pm_clock_support == 0)
return 0;
return pm_runtime_resume_and_get(cdev->dev);
}
static void m_can_clk_stop(struct m_can_classdev *cdev)
{
if (cdev->pm_clock_support)
pm_runtime_put_sync(cdev->dev);
}
static int m_can_get_berr_counter(const struct net_device *dev,
struct can_berr_counter *bec)
{
struct m_can_classdev *cdev = netdev_priv(dev);
int err;
err = m_can_clk_start(cdev);
if (err)
return err;
__m_can_get_berr_counter(dev, bec);
m_can_clk_stop(cdev);
return 0;
}
static int m_can_handle_state_change(struct net_device *dev,
enum can_state new_state)
{
struct m_can_classdev *cdev = netdev_priv(dev);
struct can_frame *cf;
struct sk_buff *skb;
struct can_berr_counter bec;
unsigned int ecr;
u32 timestamp = 0;
switch (new_state) {
case CAN_STATE_ERROR_WARNING:
/* error warning state */
cdev->can.can_stats.error_warning++;
cdev->can.state = CAN_STATE_ERROR_WARNING;
break;
case CAN_STATE_ERROR_PASSIVE:
/* error passive state */
cdev->can.can_stats.error_passive++;
cdev->can.state = CAN_STATE_ERROR_PASSIVE;
break;
case CAN_STATE_BUS_OFF:
/* bus-off state */
cdev->can.state = CAN_STATE_BUS_OFF;
m_can_disable_all_interrupts(cdev);
cdev->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_WARNING:
/* error warning state */
cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;
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 | CAN_ERR_CNT;
ecr = m_can_read(cdev, 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;
}
if (cdev->is_peripheral)
timestamp = m_can_get_timestamp(cdev);
m_can_receive_skb(cdev, skb, timestamp);
return 1;
}
static int m_can_handle_state_errors(struct net_device *dev, u32 psr)
{
struct m_can_classdev *cdev = netdev_priv(dev);
int work_done = 0;
if (psr & PSR_EW && cdev->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 && cdev->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 && cdev->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_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(u8 lec)
{
return lec != LEC_NO_ERROR && lec != LEC_NO_CHANGE;
}
static inline bool m_can_is_protocol_err(u32 irqstatus)
{
return irqstatus & IR_ERR_LEC_31X;
}
static int m_can_handle_protocol_error(struct net_device *dev, u32 irqstatus)
{
struct net_device_stats *stats = &dev->stats;
struct m_can_classdev *cdev = netdev_priv(dev);
struct can_frame *cf;
struct sk_buff *skb;
u32 timestamp = 0;
/* propagate the error condition to the CAN stack */
skb = alloc_can_err_skb(dev, &cf);
/* update tx error stats since there is protocol error */
stats->tx_errors++;
/* update arbitration lost status */
if (cdev->version >= 31 && (irqstatus & IR_PEA)) {
netdev_dbg(dev, "Protocol error in Arbitration fail\n");
cdev->can.can_stats.arbitration_lost++;
if (skb) {
cf->can_id |= CAN_ERR_LOSTARB;
cf->data[0] |= CAN_ERR_LOSTARB_UNSPEC;
}
}
if (unlikely(!skb)) {
netdev_dbg(dev, "allocation of skb failed\n");
return 0;
}
if (cdev->is_peripheral)
timestamp = m_can_get_timestamp(cdev);
m_can_receive_skb(cdev, skb, timestamp);
return 1;
}
static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
u32 psr)
{
struct m_can_classdev *cdev = 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 (cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
u8 lec = FIELD_GET(PSR_LEC_MASK, psr);
u8 dlec = FIELD_GET(PSR_DLEC_MASK, psr);
if (is_lec_err(lec)) {
netdev_dbg(dev, "Arbitration phase error detected\n");
work_done += m_can_handle_lec_err(dev, lec);
}
if (is_lec_err(dlec)) {
netdev_dbg(dev, "Data phase error detected\n");
work_done += m_can_handle_lec_err(dev, dlec);
}
}
/* handle protocol errors in arbitration phase */
if ((cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
m_can_is_protocol_err(irqstatus))
work_done += m_can_handle_protocol_error(dev, irqstatus);
/* other unproccessed error interrupts */
m_can_handle_other_err(dev, irqstatus);
return work_done;
}
static int m_can_rx_handler(struct net_device *dev, int quota, u32 irqstatus)
{
struct m_can_classdev *cdev = netdev_priv(dev);
int rx_work_or_err;
int work_done = 0;
if (!irqstatus)
goto end;
/* Errata workaround for issue "Needless activation of MRAF irq"
* During frame reception while the MCAN is in Error Passive state
* and the Receive Error Counter has the value MCAN_ECR.REC = 127,
* it may happen that MCAN_IR.MRAF is set although there was no
* Message RAM access failure.
* If MCAN_IR.MRAF is enabled, an interrupt to the Host CPU is generated
* The Message RAM Access Failure interrupt routine needs to check
* whether MCAN_ECR.RP = ’1’ and MCAN_ECR.REC = 127.
* In this case, reset MCAN_IR.MRAF. No further action is required.
*/
if (cdev->version <= 31 && irqstatus & IR_MRAF &&
m_can_read(cdev, M_CAN_ECR) & ECR_RP) {
struct can_berr_counter bec;
__m_can_get_berr_counter(dev, &bec);
if (bec.rxerr == 127) {
m_can_write(cdev, M_CAN_IR, IR_MRAF);
irqstatus &= ~IR_MRAF;
}
}
if (irqstatus & IR_ERR_STATE)
work_done += m_can_handle_state_errors(dev,
m_can_read(cdev, M_CAN_PSR));
if (irqstatus & IR_ERR_BUS_30X)
work_done += m_can_handle_bus_errors(dev, irqstatus,
m_can_read(cdev, M_CAN_PSR));
if (irqstatus & IR_RF0N) {
rx_work_or_err = m_can_do_rx_poll(dev, (quota - work_done));
if (rx_work_or_err < 0)
return rx_work_or_err;
work_done += rx_work_or_err;
}
end:
return work_done;
}
static int m_can_rx_peripheral(struct net_device *dev, u32 irqstatus)
{
struct m_can_classdev *cdev = netdev_priv(dev);
int work_done;
work_done = m_can_rx_handler(dev, NAPI_POLL_WEIGHT, irqstatus);
/* Don't re-enable interrupts if the driver had a fatal error
* (e.g., FIFO read failure).
*/
if (work_done >= 0)
m_can_enable_all_interrupts(cdev);
return work_done;
}
static int m_can_poll(struct napi_struct *napi, int quota)
{
struct net_device *dev = napi->dev;
struct m_can_classdev *cdev = netdev_priv(dev);
int work_done;
u32 irqstatus;
irqstatus = cdev->irqstatus | m_can_read(cdev, M_CAN_IR);
work_done = m_can_rx_handler(dev, quota, irqstatus);
/* Don't re-enable interrupts if the driver had a fatal error
* (e.g., FIFO read failure).
*/
if (work_done >= 0 && work_done < quota) {
napi_complete_done(napi, work_done);
m_can_enable_all_interrupts(cdev);
}
return work_done;
}
/* Echo tx skb and update net stats. Peripherals use rx-offload for
* echo. timestamp is used for peripherals to ensure correct ordering
* by rx-offload, and is ignored for non-peripherals.
*/
static void m_can_tx_update_stats(struct m_can_classdev *cdev,
unsigned int msg_mark,
u32 timestamp)
{
struct net_device *dev = cdev->net;
struct net_device_stats *stats = &dev->stats;
if (cdev->is_peripheral)
stats->tx_bytes +=
can_rx_offload_get_echo_skb(&cdev->offload,
msg_mark,
timestamp,
NULL);
else
stats->tx_bytes += can_get_echo_skb(dev, msg_mark, NULL);
stats->tx_packets++;
}
static int m_can_echo_tx_event(struct net_device *dev)
{
u32 txe_count = 0;
u32 m_can_txefs;
u32 fgi = 0;
int ack_fgi = -1;
int i = 0;
int err = 0;
unsigned int msg_mark;
struct m_can_classdev *cdev = netdev_priv(dev);
/* read tx event fifo status */
m_can_txefs = m_can_read(cdev, M_CAN_TXEFS);
/* Get Tx Event fifo element count */
txe_count = FIELD_GET(TXEFS_EFFL_MASK, m_can_txefs);
fgi = FIELD_GET(TXEFS_EFGI_MASK, m_can_txefs);
/* Get and process all sent elements */
for (i = 0; i < txe_count; i++) {
u32 txe, timestamp = 0;
/* get message marker, timestamp */
err = m_can_txe_fifo_read(cdev, fgi, 4, &txe);
if (err) {
netdev_err(dev, "TXE FIFO read returned %d\n", err);
break;
}
msg_mark = FIELD_GET(TX_EVENT_MM_MASK, txe);
timestamp = FIELD_GET(TX_EVENT_TXTS_MASK, txe) << 16;
ack_fgi = fgi;
fgi = (++fgi >= cdev->mcfg[MRAM_TXE].num ? 0 : fgi);
/* update stats */
m_can_tx_update_stats(cdev, msg_mark, timestamp);
}
if (ack_fgi != -1)
m_can_write(cdev, M_CAN_TXEFA, FIELD_PREP(TXEFA_EFAI_MASK,
ack_fgi));
return err;
}
static irqreturn_t m_can_isr(int irq, void *dev_id)
{
struct net_device *dev = (struct net_device *)dev_id;
struct m_can_classdev *cdev = netdev_priv(dev);
u32 ir;
if (pm_runtime_suspended(cdev->dev))
return IRQ_NONE;
ir = m_can_read(cdev, M_CAN_IR);
if (!ir)
return IRQ_NONE;
/* ACK all irqs */
if (ir & IR_ALL_INT)
m_can_write(cdev, M_CAN_IR, ir);
if (cdev->ops->clear_interrupts)
cdev->ops->clear_interrupts(cdev);
/* 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)) {
cdev->irqstatus = ir;
m_can_disable_all_interrupts(cdev);
if (!cdev->is_peripheral)
napi_schedule(&cdev->napi);
else if (m_can_rx_peripheral(dev, ir) < 0)
goto out_fail;
}
if (cdev->version == 30) {
if (ir & IR_TC) {
/* Transmission Complete Interrupt*/
u32 timestamp = 0;
if (cdev->is_peripheral)
timestamp = m_can_get_timestamp(cdev);
m_can_tx_update_stats(cdev, 0, timestamp);
netif_wake_queue(dev);
}
} else {
if (ir & IR_TEFN) {
/* New TX FIFO Element arrived */
if (m_can_echo_tx_event(dev) != 0)
goto out_fail;
if (netif_queue_stopped(dev) &&
!m_can_tx_fifo_full(cdev))
netif_wake_queue(dev);
}
}
if (cdev->is_peripheral)
can_rx_offload_threaded_irq_finish(&cdev->offload);
return IRQ_HANDLED;
out_fail:
m_can_disable_all_interrupts(cdev);
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 = 2, /* 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_classdev *cdev = netdev_priv(dev);
const struct can_bittiming *bt = &cdev->can.bittiming;
const struct can_bittiming *dbt = &cdev->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 = FIELD_PREP(NBTP_NBRP_MASK, brp) |
FIELD_PREP(NBTP_NSJW_MASK, sjw) |
FIELD_PREP(NBTP_NTSEG1_MASK, tseg1) |
FIELD_PREP(NBTP_NTSEG2_MASK, tseg2);
m_can_write(cdev, M_CAN_NBTP, reg_btp);
if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
reg_btp = 0;
brp = dbt->brp - 1;
sjw = dbt->sjw - 1;
tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
tseg2 = dbt->phase_seg2 - 1;
/* TDC is only needed for bitrates beyond 2.5 MBit/s.
* This is mentioned in the "Bit Time Requirements for CAN FD"
* paper presented at the International CAN Conference 2013
*/
if (dbt->bitrate > 2500000) {
u32 tdco, ssp;
/* Use the same value of secondary sampling point
* as the data sampling point
*/
ssp = dbt->sample_point;
/* Equation based on Bosch's M_CAN User Manual's
* Transmitter Delay Compensation Section
*/
tdco = (cdev->can.clock.freq / 1000) *
ssp / dbt->bitrate;
/* Max valid TDCO value is 127 */
if (tdco > 127) {
netdev_warn(dev, "TDCO value of %u is beyond maximum. Using maximum possible value\n",
tdco);
tdco = 127;
}
reg_btp |= DBTP_TDC;
m_can_write(cdev, M_CAN_TDCR,
FIELD_PREP(TDCR_TDCO_MASK, tdco));
}
reg_btp |= FIELD_PREP(DBTP_DBRP_MASK, brp) |
FIELD_PREP(DBTP_DSJW_MASK, sjw) |
FIELD_PREP(DBTP_DTSEG1_MASK, tseg1) |
FIELD_PREP(DBTP_DTSEG2_MASK, tseg2);
m_can_write(cdev, 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
* - configure timestamp generation
*/
static int m_can_chip_config(struct net_device *dev)
{
struct m_can_classdev *cdev = netdev_priv(dev);
u32 cccr, test;
int err;
err = m_can_init_ram(cdev);
if (err) {
dev_err(cdev->dev, "Message RAM configuration failed\n");
return err;
}
m_can_config_endisable(cdev, true);
/* RX Buffer/FIFO Element Size 64 bytes data field */
m_can_write(cdev, M_CAN_RXESC,
FIELD_PREP(RXESC_RBDS_MASK, RXESC_64B) |
FIELD_PREP(RXESC_F1DS_MASK, RXESC_64B) |
FIELD_PREP(RXESC_F0DS_MASK, RXESC_64B));
/* Accept Non-matching Frames Into FIFO 0 */
m_can_write(cdev, M_CAN_GFC, 0x0);
if (cdev->version == 30) {
/* only support one Tx Buffer currently */
m_can_write(cdev, M_CAN_TXBC, FIELD_PREP(TXBC_NDTB_MASK, 1) |
cdev->mcfg[MRAM_TXB].off);
} else {
/* TX FIFO is used for newer IP Core versions */
m_can_write(cdev, M_CAN_TXBC,
FIELD_PREP(TXBC_TFQS_MASK,
cdev->mcfg[MRAM_TXB].num) |
cdev->mcfg[MRAM_TXB].off);
}
/* support 64 bytes payload */
m_can_write(cdev, M_CAN_TXESC,
FIELD_PREP(TXESC_TBDS_MASK, TXESC_TBDS_64B));
/* TX Event FIFO */
if (cdev->version == 30) {
m_can_write(cdev, M_CAN_TXEFC,
FIELD_PREP(TXEFC_EFS_MASK, 1) |
cdev->mcfg[MRAM_TXE].off);
} else {
/* Full TX Event FIFO is used */
m_can_write(cdev, M_CAN_TXEFC,
FIELD_PREP(TXEFC_EFS_MASK,
cdev->mcfg[MRAM_TXE].num) |
cdev->mcfg[MRAM_TXE].off);
}
/* rx fifo configuration, blocking mode, fifo size 1 */
m_can_write(cdev, M_CAN_RXF0C,
FIELD_PREP(RXFC_FS_MASK, cdev->mcfg[MRAM_RXF0].num) |
cdev->mcfg[MRAM_RXF0].off);
m_can_write(cdev, M_CAN_RXF1C,
FIELD_PREP(RXFC_FS_MASK, cdev->mcfg[MRAM_RXF1].num) |
cdev->mcfg[MRAM_RXF1].off);
cccr = m_can_read(cdev, M_CAN_CCCR);
test = m_can_read(cdev, M_CAN_TEST);
test &= ~TEST_LBCK;
if (cdev->version == 30) {
/* Version 3.0.x */
cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_DAR |
FIELD_PREP(CCCR_CMR_MASK, FIELD_MAX(CCCR_CMR_MASK)) |
FIELD_PREP(CCCR_CME_MASK, FIELD_MAX(CCCR_CME_MASK)));
if (cdev->can.ctrlmode & CAN_CTRLMODE_FD)
cccr |= FIELD_PREP(CCCR_CME_MASK, CCCR_CME_CANFD_BRS);
} else {
/* Version 3.1.x or 3.2.x */
cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_BRSE | CCCR_FDOE |
CCCR_NISO | CCCR_DAR);
/* Only 3.2.x has NISO Bit implemented */
if (cdev->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
cccr |= CCCR_NISO;
if (cdev->can.ctrlmode & CAN_CTRLMODE_FD)
cccr |= (CCCR_BRSE | CCCR_FDOE);
}
/* Loopback Mode */
if (cdev->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
cccr |= CCCR_TEST | CCCR_MON;
test |= TEST_LBCK;
}
/* Enable Monitoring (all versions) */
if (cdev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
cccr |= CCCR_MON;
/* Disable Auto Retransmission (all versions) */
if (cdev->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
cccr |= CCCR_DAR;
/* Write config */
m_can_write(cdev, M_CAN_CCCR, cccr);
m_can_write(cdev, M_CAN_TEST, test);
/* Enable interrupts */
m_can_write(cdev, M_CAN_IR, IR_ALL_INT);
if (!(cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
if (cdev->version == 30)
m_can_write(cdev, M_CAN_IE, IR_ALL_INT &
~(IR_ERR_LEC_30X));
else
m_can_write(cdev, M_CAN_IE, IR_ALL_INT &
~(IR_ERR_LEC_31X));
else
m_can_write(cdev, M_CAN_IE, IR_ALL_INT);
/* route all interrupts to INT0 */
m_can_write(cdev, M_CAN_ILS, ILS_ALL_INT0);
/* set bittiming params */
m_can_set_bittiming(dev);
/* enable internal timestamp generation, with a prescaler of 16. The
* prescaler is applied to the nominal bit timing
*/
m_can_write(cdev, M_CAN_TSCC,
FIELD_PREP(TSCC_TCP_MASK, 0xf) |
FIELD_PREP(TSCC_TSS_MASK, TSCC_TSS_INTERNAL));
m_can_config_endisable(cdev, false);
if (cdev->ops->init)
cdev->ops->init(cdev);
return 0;
}
static int m_can_start(struct net_device *dev)
{
struct m_can_classdev *cdev = netdev_priv(dev);
int ret;
/* basic m_can configuration */
ret = m_can_chip_config(dev);
if (ret)
return ret;
cdev->can.state = CAN_STATE_ERROR_ACTIVE;
m_can_enable_all_interrupts(cdev);
return 0;
}
static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
{
switch (mode) {
case CAN_MODE_START:
m_can_clean(dev);
m_can_start(dev);
netif_wake_queue(dev);
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
/* 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(struct m_can_classdev *cdev)
{
u32 crel_reg;
u8 rel;
u8 step;
int res;
/* 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(cdev, M_CAN_CREL);
rel = (u8)FIELD_GET(CREL_REL_MASK, crel_reg);
step = (u8)FIELD_GET(CREL_STEP_MASK, crel_reg);
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(struct m_can_classdev *cdev)
{
u32 cccr_reg, cccr_poll = 0;
int niso_timeout = -ETIMEDOUT;
int i;
m_can_config_endisable(cdev, true);
cccr_reg = m_can_read(cdev, M_CAN_CCCR);
cccr_reg |= CCCR_NISO;
m_can_write(cdev, M_CAN_CCCR, cccr_reg);
for (i = 0; i <= 10; i++) {
cccr_poll = m_can_read(cdev, M_CAN_CCCR);
if (cccr_poll == cccr_reg) {
niso_timeout = 0;
break;
}
usleep_range(1, 5);
}
/* Clear NISO */
cccr_reg &= ~(CCCR_NISO);
m_can_write(cdev, M_CAN_CCCR, cccr_reg);
m_can_config_endisable(cdev, false);
/* return false if time out (-ETIMEDOUT), else return true */
return !niso_timeout;
}
static int m_can_dev_setup(struct m_can_classdev *cdev)
{
struct net_device *dev = cdev->net;
int m_can_version, err;
m_can_version = m_can_check_core_release(cdev);
/* return if unsupported version */
if (!m_can_version) {
dev_err(cdev->dev, "Unsupported version number: %2d",
m_can_version);
return -EINVAL;
}
if (!cdev->is_peripheral)
netif_napi_add(dev, &cdev->napi, m_can_poll);
/* Shared properties of all M_CAN versions */
cdev->version = m_can_version;
cdev->can.do_set_mode = m_can_set_mode;
cdev->can.do_get_berr_counter = m_can_get_berr_counter;
/* Set M_CAN supported operations */
cdev->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
CAN_CTRLMODE_LISTENONLY |
CAN_CTRLMODE_BERR_REPORTING |
CAN_CTRLMODE_FD |
CAN_CTRLMODE_ONE_SHOT;
/* Set properties depending on M_CAN version */
switch (cdev->version) {
case 30:
/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */
err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
if (err)
return err;
cdev->can.bittiming_const = &m_can_bittiming_const_30X;
cdev->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 */
err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
if (err)
return err;
cdev->can.bittiming_const = &m_can_bittiming_const_31X;
cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X;
break;
case 32:
case 33:
/* Support both MCAN version v3.2.x and v3.3.0 */
cdev->can.bittiming_const = &m_can_bittiming_const_31X;
cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X;
cdev->can.ctrlmode_supported |=
(m_can_niso_supported(cdev) ?
CAN_CTRLMODE_FD_NON_ISO : 0);
break;
default:
dev_err(cdev->dev, "Unsupported version number: %2d",
cdev->version);
return -EINVAL;
}
if (cdev->ops->init)
cdev->ops->init(cdev);
return 0;
}
static void m_can_stop(struct net_device *dev)
{
struct m_can_classdev *cdev = netdev_priv(dev);
/* disable all interrupts */
m_can_disable_all_interrupts(cdev);
/* Set init mode to disengage from the network */
m_can_config_endisable(cdev, true);
/* set the state as STOPPED */
cdev->can.state = CAN_STATE_STOPPED;
}
static int m_can_close(struct net_device *dev)
{
struct m_can_classdev *cdev = netdev_priv(dev);
netif_stop_queue(dev);
if (!cdev->is_peripheral)
napi_disable(&cdev->napi);
m_can_stop(dev);
m_can_clk_stop(cdev);
free_irq(dev->irq, dev);
if (cdev->is_peripheral) {
cdev->tx_skb = NULL;
destroy_workqueue(cdev->tx_wq);
cdev->tx_wq = NULL;
}
if (cdev->is_peripheral)
can_rx_offload_disable(&cdev->offload);
close_candev(dev);
phy_power_off(cdev->transceiver);
return 0;
}
static int m_can_next_echo_skb_occupied(struct net_device *dev, int putidx)
{
struct m_can_classdev *cdev = netdev_priv(dev);
/*get wrap around for loopback skb index */
unsigned int wrap = cdev->can.echo_skb_max;
int next_idx;
/* calculate next index */
next_idx = (++putidx >= wrap ? 0 : putidx);
/* check if occupied */
return !!cdev->can.echo_skb[next_idx];
}
static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
{
struct canfd_frame *cf = (struct canfd_frame *)cdev->tx_skb->data;
struct net_device *dev = cdev->net;
struct sk_buff *skb = cdev->tx_skb;
struct id_and_dlc fifo_header;
u32 cccr, fdflags;
u32 txfqs;
int err;
int putidx;
cdev->tx_skb = NULL;
/* Generate ID field for TX buffer Element */
/* Common to all supported M_CAN versions */
if (cf->can_id & CAN_EFF_FLAG) {
fifo_header.id = cf->can_id & CAN_EFF_MASK;
fifo_header.id |= TX_BUF_XTD;
} else {
fifo_header.id = ((cf->can_id & CAN_SFF_MASK) << 18);
}
if (cf->can_id & CAN_RTR_FLAG)
fifo_header.id |= TX_BUF_RTR;
if (cdev->version == 30) {
netif_stop_queue(dev);
fifo_header.dlc = can_fd_len2dlc(cf->len) << 16;
/* Write the frame ID, DLC, and payload to the FIFO element. */
err = m_can_fifo_write(cdev, 0, M_CAN_FIFO_ID, &fifo_header, 2);
if (err)
goto out_fail;
err = m_can_fifo_write(cdev, 0, M_CAN_FIFO_DATA,
cf->data, DIV_ROUND_UP(cf->len, 4));
if (err)
goto out_fail;
if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
cccr = m_can_read(cdev, M_CAN_CCCR);
cccr &= ~CCCR_CMR_MASK;
if (can_is_canfd_skb(skb)) {
if (cf->flags & CANFD_BRS)
cccr |= FIELD_PREP(CCCR_CMR_MASK,
CCCR_CMR_CANFD_BRS);
else
cccr |= FIELD_PREP(CCCR_CMR_MASK,
CCCR_CMR_CANFD);
} else {
cccr |= FIELD_PREP(CCCR_CMR_MASK, CCCR_CMR_CAN);
}
m_can_write(cdev, M_CAN_CCCR, cccr);
}
m_can_write(cdev, M_CAN_TXBTIE, 0x1);
can_put_echo_skb(skb, dev, 0, 0);
m_can_write(cdev, M_CAN_TXBAR, 0x1);
/* End of xmit function for version 3.0.x */
} else {
/* Transmit routine for version >= v3.1.x */
txfqs = m_can_read(cdev, M_CAN_TXFQS);
/* Check if FIFO full */
if (_m_can_tx_fifo_full(txfqs)) {
/* This shouldn't happen */
netif_stop_queue(dev);
netdev_warn(dev,
"TX queue active although FIFO is full.");
if (cdev->is_peripheral) {
kfree_skb(skb);
dev->stats.tx_dropped++;
return NETDEV_TX_OK;
} else {
return NETDEV_TX_BUSY;
}
}
/* get put index for frame */
putidx = FIELD_GET(TXFQS_TFQPI_MASK, txfqs);
/* Construct DLC Field, with CAN-FD configuration.
* Use the put index of the fifo as the message marker,
* used in the TX interrupt for sending the correct echo frame.
*/
/* 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;
}
fifo_header.dlc = FIELD_PREP(TX_BUF_MM_MASK, putidx) |
FIELD_PREP(TX_BUF_DLC_MASK, can_fd_len2dlc(cf->len)) |
fdflags | TX_BUF_EFC;
err = m_can_fifo_write(cdev, putidx, M_CAN_FIFO_ID, &fifo_header, 2);
if (err)
goto out_fail;
err = m_can_fifo_write(cdev, putidx, M_CAN_FIFO_DATA,
cf->data, DIV_ROUND_UP(cf->len, 4));
if (err)
goto out_fail;
/* Push loopback echo.
* Will be looped back on TX interrupt based on message marker
*/
can_put_echo_skb(skb, dev, putidx, 0);
/* Enable TX FIFO element to start transfer */
m_can_write(cdev, M_CAN_TXBAR, (1 << putidx));
/* stop network queue if fifo full */
if (m_can_tx_fifo_full(cdev) ||
m_can_next_echo_skb_occupied(dev, putidx))
netif_stop_queue(dev);
}
return NETDEV_TX_OK;
out_fail:
netdev_err(dev, "FIFO write returned %d\n", err);
m_can_disable_all_interrupts(cdev);
return NETDEV_TX_BUSY;
}
static void m_can_tx_work_queue(struct work_struct *ws)
{
struct m_can_classdev *cdev = container_of(ws, struct m_can_classdev,
tx_work);
m_can_tx_handler(cdev);
}
static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct m_can_classdev *cdev = netdev_priv(dev);
if (can_dev_dropped_skb(dev, skb))
return NETDEV_TX_OK;
if (cdev->is_peripheral) {
if (cdev->tx_skb) {
netdev_err(dev, "hard_xmit called while tx busy\n");
return NETDEV_TX_BUSY;
}
if (cdev->can.state == CAN_STATE_BUS_OFF) {
m_can_clean(dev);
} else {
/* Need to stop the queue to avoid numerous requests
* from being sent. Suggested improvement is to create
* a queueing mechanism that will queue the skbs and
* process them in order.
*/
cdev->tx_skb = skb;
netif_stop_queue(cdev->net);
queue_work(cdev->tx_wq, &cdev->tx_work);
}
} else {
cdev->tx_skb = skb;
return m_can_tx_handler(cdev);
}
return NETDEV_TX_OK;
}
static int m_can_open(struct net_device *dev)
{
struct m_can_classdev *cdev = netdev_priv(dev);
int err;
err = phy_power_on(cdev->transceiver);
if (err)
return err;
err = m_can_clk_start(cdev);
if (err)
goto out_phy_power_off;
/* open the can device */
err = open_candev(dev);
if (err) {
netdev_err(dev, "failed to open can device\n");
goto exit_disable_clks;
}
if (cdev->is_peripheral)
can_rx_offload_enable(&cdev->offload);
/* register interrupt handler */
if (cdev->is_peripheral) {
cdev->tx_skb = NULL;
cdev->tx_wq = alloc_workqueue("mcan_wq",
WQ_FREEZABLE | WQ_MEM_RECLAIM, 0);
if (!cdev->tx_wq) {
err = -ENOMEM;
goto out_wq_fail;
}
INIT_WORK(&cdev->tx_work, m_can_tx_work_queue);
err = request_threaded_irq(dev->irq, NULL, m_can_isr,
IRQF_ONESHOT,
dev->name, dev);
} else {
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 */
err = m_can_start(dev);
if (err)
goto exit_irq_fail;
if (!cdev->is_peripheral)
napi_enable(&cdev->napi);
netif_start_queue(dev);
return 0;
exit_irq_fail:
if (cdev->is_peripheral)
destroy_workqueue(cdev->tx_wq);
out_wq_fail:
if (cdev->is_peripheral)
can_rx_offload_disable(&cdev->offload);
close_candev(dev);
exit_disable_clks:
m_can_clk_stop(cdev);
out_phy_power_off:
phy_power_off(cdev->transceiver);
return err;
}
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 const struct ethtool_ops m_can_ethtool_ops = {
.get_ts_info = ethtool_op_get_ts_info,
};
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;
dev->ethtool_ops = &m_can_ethtool_ops;
return register_candev(dev);
}
static void m_can_of_parse_mram(struct m_can_classdev *cdev,
const u32 *mram_config_vals)
{
cdev->mcfg[MRAM_SIDF].off = mram_config_vals[0];
cdev->mcfg[MRAM_SIDF].num = mram_config_vals[1];
cdev->mcfg[MRAM_XIDF].off = cdev->mcfg[MRAM_SIDF].off +
cdev->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE;
cdev->mcfg[MRAM_XIDF].num = mram_config_vals[2];
cdev->mcfg[MRAM_RXF0].off = cdev->mcfg[MRAM_XIDF].off +
cdev->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE;
cdev->mcfg[MRAM_RXF0].num = mram_config_vals[3] &
FIELD_MAX(RXFC_FS_MASK);
cdev->mcfg[MRAM_RXF1].off = cdev->mcfg[MRAM_RXF0].off +
cdev->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE;
cdev->mcfg[MRAM_RXF1].num = mram_config_vals[4] &
FIELD_MAX(RXFC_FS_MASK);
cdev->mcfg[MRAM_RXB].off = cdev->mcfg[MRAM_RXF1].off +
cdev->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE;
cdev->mcfg[MRAM_RXB].num = mram_config_vals[5];
cdev->mcfg[MRAM_TXE].off = cdev->mcfg[MRAM_RXB].off +
cdev->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE;
cdev->mcfg[MRAM_TXE].num = mram_config_vals[6];
cdev->mcfg[MRAM_TXB].off = cdev->mcfg[MRAM_TXE].off +
cdev->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE;
cdev->mcfg[MRAM_TXB].num = mram_config_vals[7] &
FIELD_MAX(TXBC_NDTB_MASK);
dev_dbg(cdev->dev,
"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",
cdev->mcfg[MRAM_SIDF].off, cdev->mcfg[MRAM_SIDF].num,
cdev->mcfg[MRAM_XIDF].off, cdev->mcfg[MRAM_XIDF].num,
cdev->mcfg[MRAM_RXF0].off, cdev->mcfg[MRAM_RXF0].num,
cdev->mcfg[MRAM_RXF1].off, cdev->mcfg[MRAM_RXF1].num,
cdev->mcfg[MRAM_RXB].off, cdev->mcfg[MRAM_RXB].num,
cdev->mcfg[MRAM_TXE].off, cdev->mcfg[MRAM_TXE].num,
cdev->mcfg[MRAM_TXB].off, cdev->mcfg[MRAM_TXB].num);
}
int m_can_init_ram(struct m_can_classdev *cdev)
{
int end, i, start;
int err = 0;
/* initialize the entire Message RAM in use to avoid possible
* ECC/parity checksum errors when reading an uninitialized buffer
*/
start = cdev->mcfg[MRAM_SIDF].off;
end = cdev->mcfg[MRAM_TXB].off +
cdev->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
for (i = start; i < end; i += 4) {
err = m_can_fifo_write_no_off(cdev, i, 0x0);
if (err)
break;
}
return err;
}
EXPORT_SYMBOL_GPL(m_can_init_ram);
int m_can_class_get_clocks(struct m_can_classdev *cdev)
{
int ret = 0;
cdev->hclk = devm_clk_get(cdev->dev, "hclk");
cdev->cclk = devm_clk_get(cdev->dev, "cclk");
if (IS_ERR(cdev->hclk) || IS_ERR(cdev->cclk)) {
dev_err(cdev->dev, "no clock found\n");
ret = -ENODEV;
}
return ret;
}
EXPORT_SYMBOL_GPL(m_can_class_get_clocks);
struct m_can_classdev *m_can_class_allocate_dev(struct device *dev,
int sizeof_priv)
{
struct m_can_classdev *class_dev = NULL;
u32 mram_config_vals[MRAM_CFG_LEN];
struct net_device *net_dev;
u32 tx_fifo_size;
int ret;
ret = fwnode_property_read_u32_array(dev_fwnode(dev),
"bosch,mram-cfg",
mram_config_vals,
sizeof(mram_config_vals) / 4);
if (ret) {
dev_err(dev, "Could not get Message RAM configuration.");
goto out;
}
/* 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 */
net_dev = alloc_candev(sizeof_priv, tx_fifo_size);
if (!net_dev) {
dev_err(dev, "Failed to allocate CAN device");
goto out;
}
class_dev = netdev_priv(net_dev);
class_dev->net = net_dev;
class_dev->dev = dev;
SET_NETDEV_DEV(net_dev, dev);
m_can_of_parse_mram(class_dev, mram_config_vals);
out:
return class_dev;
}
EXPORT_SYMBOL_GPL(m_can_class_allocate_dev);
void m_can_class_free_dev(struct net_device *net)
{
free_candev(net);
}
EXPORT_SYMBOL_GPL(m_can_class_free_dev);
int m_can_class_register(struct m_can_classdev *cdev)
{
int ret;
if (cdev->pm_clock_support) {
ret = m_can_clk_start(cdev);
if (ret)
return ret;
}
if (cdev->is_peripheral) {
ret = can_rx_offload_add_manual(cdev->net, &cdev->offload,
NAPI_POLL_WEIGHT);
if (ret)
goto clk_disable;
}
ret = m_can_dev_setup(cdev);
if (ret)
goto rx_offload_del;
ret = register_m_can_dev(cdev->net);
if (ret) {
dev_err(cdev->dev, "registering %s failed (err=%d)\n",
cdev->net->name, ret);
goto rx_offload_del;
}
of_can_transceiver(cdev->net);
dev_info(cdev->dev, "%s device registered (irq=%d, version=%d)\n",
KBUILD_MODNAME, cdev->net->irq, cdev->version);
/* Probe finished
* Stop clocks. They will be reactivated once the M_CAN device is opened
*/
m_can_clk_stop(cdev);
return 0;
rx_offload_del:
if (cdev->is_peripheral)
can_rx_offload_del(&cdev->offload);
clk_disable:
m_can_clk_stop(cdev);
return ret;
}
EXPORT_SYMBOL_GPL(m_can_class_register);
void m_can_class_unregister(struct m_can_classdev *cdev)
{
if (cdev->is_peripheral)
can_rx_offload_del(&cdev->offload);
unregister_candev(cdev->net);
}
EXPORT_SYMBOL_GPL(m_can_class_unregister);
int m_can_class_suspend(struct device *dev)
{
struct m_can_classdev *cdev = dev_get_drvdata(dev);
struct net_device *ndev = cdev->net;
if (netif_running(ndev)) {
netif_stop_queue(ndev);
netif_device_detach(ndev);
m_can_stop(ndev);
m_can_clk_stop(cdev);
}
pinctrl_pm_select_sleep_state(dev);
cdev->can.state = CAN_STATE_SLEEPING;
return 0;
}
EXPORT_SYMBOL_GPL(m_can_class_suspend);
int m_can_class_resume(struct device *dev)
{
struct m_can_classdev *cdev = dev_get_drvdata(dev);
struct net_device *ndev = cdev->net;
pinctrl_pm_select_default_state(dev);
cdev->can.state = CAN_STATE_ERROR_ACTIVE;
if (netif_running(ndev)) {
int ret;
ret = m_can_clk_start(cdev);
if (ret)
return ret;
ret = m_can_start(ndev);
if (ret) {
m_can_clk_stop(cdev);
return ret;
}
netif_device_attach(ndev);
netif_start_queue(ndev);
}
return 0;
}
EXPORT_SYMBOL_GPL(m_can_class_resume);
MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");