diff options
Diffstat (limited to 'drivers/net/can/xilinx_can.c')
| -rw-r--r-- | drivers/net/can/xilinx_can.c | 1878 |
1 files changed, 1878 insertions, 0 deletions
diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c new file mode 100644 index 000000000..1a3fba352 --- /dev/null +++ b/drivers/net/can/xilinx_can.c @@ -0,0 +1,1878 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Xilinx CAN device driver + * + * Copyright (C) 2012 - 2014 Xilinx, Inc. + * Copyright (C) 2009 PetaLogix. All rights reserved. + * Copyright (C) 2017 - 2018 Sandvik Mining and Construction Oy + * + * Description: + * This driver is developed for Axi CAN IP and for Zynq CANPS Controller. + */ + +#include <linux/clk.h> +#include <linux/errno.h> +#include <linux/init.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/skbuff.h> +#include <linux/spinlock.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/can/dev.h> +#include <linux/can/error.h> +#include <linux/can/led.h> +#include <linux/pm_runtime.h> + +#define DRIVER_NAME "xilinx_can" + +/* CAN registers set */ +enum xcan_reg { + XCAN_SRR_OFFSET = 0x00, /* Software reset */ + XCAN_MSR_OFFSET = 0x04, /* Mode select */ + XCAN_BRPR_OFFSET = 0x08, /* Baud rate prescaler */ + XCAN_BTR_OFFSET = 0x0C, /* Bit timing */ + XCAN_ECR_OFFSET = 0x10, /* Error counter */ + XCAN_ESR_OFFSET = 0x14, /* Error status */ + XCAN_SR_OFFSET = 0x18, /* Status */ + XCAN_ISR_OFFSET = 0x1C, /* Interrupt status */ + XCAN_IER_OFFSET = 0x20, /* Interrupt enable */ + XCAN_ICR_OFFSET = 0x24, /* Interrupt clear */ + + /* not on CAN FD cores */ + XCAN_TXFIFO_OFFSET = 0x30, /* TX FIFO base */ + XCAN_RXFIFO_OFFSET = 0x50, /* RX FIFO base */ + XCAN_AFR_OFFSET = 0x60, /* Acceptance Filter */ + + /* only on CAN FD cores */ + XCAN_F_BRPR_OFFSET = 0x088, /* Data Phase Baud Rate + * Prescalar + */ + XCAN_F_BTR_OFFSET = 0x08C, /* Data Phase Bit Timing */ + XCAN_TRR_OFFSET = 0x0090, /* TX Buffer Ready Request */ + XCAN_AFR_EXT_OFFSET = 0x00E0, /* Acceptance Filter */ + XCAN_FSR_OFFSET = 0x00E8, /* RX FIFO Status */ + XCAN_TXMSG_BASE_OFFSET = 0x0100, /* TX Message Space */ + XCAN_RXMSG_BASE_OFFSET = 0x1100, /* RX Message Space */ + XCAN_RXMSG_2_BASE_OFFSET = 0x2100, /* RX Message Space */ + XCAN_AFR_2_MASK_OFFSET = 0x0A00, /* Acceptance Filter MASK */ + XCAN_AFR_2_ID_OFFSET = 0x0A04, /* Acceptance Filter ID */ +}; + +#define XCAN_FRAME_ID_OFFSET(frame_base) ((frame_base) + 0x00) +#define XCAN_FRAME_DLC_OFFSET(frame_base) ((frame_base) + 0x04) +#define XCAN_FRAME_DW1_OFFSET(frame_base) ((frame_base) + 0x08) +#define XCAN_FRAME_DW2_OFFSET(frame_base) ((frame_base) + 0x0C) +#define XCANFD_FRAME_DW_OFFSET(frame_base) ((frame_base) + 0x08) + +#define XCAN_CANFD_FRAME_SIZE 0x48 +#define XCAN_TXMSG_FRAME_OFFSET(n) (XCAN_TXMSG_BASE_OFFSET + \ + XCAN_CANFD_FRAME_SIZE * (n)) +#define XCAN_RXMSG_FRAME_OFFSET(n) (XCAN_RXMSG_BASE_OFFSET + \ + XCAN_CANFD_FRAME_SIZE * (n)) +#define XCAN_RXMSG_2_FRAME_OFFSET(n) (XCAN_RXMSG_2_BASE_OFFSET + \ + XCAN_CANFD_FRAME_SIZE * (n)) + +/* the single TX mailbox used by this driver on CAN FD HW */ +#define XCAN_TX_MAILBOX_IDX 0 + +/* CAN register bit masks - XCAN_<REG>_<BIT>_MASK */ +#define XCAN_SRR_CEN_MASK 0x00000002 /* CAN enable */ +#define XCAN_SRR_RESET_MASK 0x00000001 /* Soft Reset the CAN core */ +#define XCAN_MSR_LBACK_MASK 0x00000002 /* Loop back mode select */ +#define XCAN_MSR_SLEEP_MASK 0x00000001 /* Sleep mode select */ +#define XCAN_BRPR_BRP_MASK 0x000000FF /* Baud rate prescaler */ +#define XCAN_BTR_SJW_MASK 0x00000180 /* Synchronous jump width */ +#define XCAN_BTR_TS2_MASK 0x00000070 /* Time segment 2 */ +#define XCAN_BTR_TS1_MASK 0x0000000F /* Time segment 1 */ +#define XCAN_BTR_SJW_MASK_CANFD 0x000F0000 /* Synchronous jump width */ +#define XCAN_BTR_TS2_MASK_CANFD 0x00000F00 /* Time segment 2 */ +#define XCAN_BTR_TS1_MASK_CANFD 0x0000003F /* Time segment 1 */ +#define XCAN_ECR_REC_MASK 0x0000FF00 /* Receive error counter */ +#define XCAN_ECR_TEC_MASK 0x000000FF /* Transmit error counter */ +#define XCAN_ESR_ACKER_MASK 0x00000010 /* ACK error */ +#define XCAN_ESR_BERR_MASK 0x00000008 /* Bit error */ +#define XCAN_ESR_STER_MASK 0x00000004 /* Stuff error */ +#define XCAN_ESR_FMER_MASK 0x00000002 /* Form error */ +#define XCAN_ESR_CRCER_MASK 0x00000001 /* CRC error */ +#define XCAN_SR_TXFLL_MASK 0x00000400 /* TX FIFO is full */ +#define XCAN_SR_ESTAT_MASK 0x00000180 /* Error status */ +#define XCAN_SR_ERRWRN_MASK 0x00000040 /* Error warning */ +#define XCAN_SR_NORMAL_MASK 0x00000008 /* Normal mode */ +#define XCAN_SR_LBACK_MASK 0x00000002 /* Loop back mode */ +#define XCAN_SR_CONFIG_MASK 0x00000001 /* Configuration mode */ +#define XCAN_IXR_RXMNF_MASK 0x00020000 /* RX match not finished */ +#define XCAN_IXR_TXFEMP_MASK 0x00004000 /* TX FIFO Empty */ +#define XCAN_IXR_WKUP_MASK 0x00000800 /* Wake up interrupt */ +#define XCAN_IXR_SLP_MASK 0x00000400 /* Sleep interrupt */ +#define XCAN_IXR_BSOFF_MASK 0x00000200 /* Bus off interrupt */ +#define XCAN_IXR_ERROR_MASK 0x00000100 /* Error interrupt */ +#define XCAN_IXR_RXNEMP_MASK 0x00000080 /* RX FIFO NotEmpty intr */ +#define XCAN_IXR_RXOFLW_MASK 0x00000040 /* RX FIFO Overflow intr */ +#define XCAN_IXR_RXOK_MASK 0x00000010 /* Message received intr */ +#define XCAN_IXR_TXFLL_MASK 0x00000004 /* Tx FIFO Full intr */ +#define XCAN_IXR_TXOK_MASK 0x00000002 /* TX successful intr */ +#define XCAN_IXR_ARBLST_MASK 0x00000001 /* Arbitration lost intr */ +#define XCAN_IDR_ID1_MASK 0xFFE00000 /* Standard msg identifier */ +#define XCAN_IDR_SRR_MASK 0x00100000 /* Substitute remote TXreq */ +#define XCAN_IDR_IDE_MASK 0x00080000 /* Identifier extension */ +#define XCAN_IDR_ID2_MASK 0x0007FFFE /* Extended message ident */ +#define XCAN_IDR_RTR_MASK 0x00000001 /* Remote TX request */ +#define XCAN_DLCR_DLC_MASK 0xF0000000 /* Data length code */ +#define XCAN_FSR_FL_MASK 0x00003F00 /* RX Fill Level */ +#define XCAN_2_FSR_FL_MASK 0x00007F00 /* RX Fill Level */ +#define XCAN_FSR_IRI_MASK 0x00000080 /* RX Increment Read Index */ +#define XCAN_FSR_RI_MASK 0x0000001F /* RX Read Index */ +#define XCAN_2_FSR_RI_MASK 0x0000003F /* RX Read Index */ +#define XCAN_DLCR_EDL_MASK 0x08000000 /* EDL Mask in DLC */ +#define XCAN_DLCR_BRS_MASK 0x04000000 /* BRS Mask in DLC */ + +/* CAN register bit shift - XCAN_<REG>_<BIT>_SHIFT */ +#define XCAN_BTR_SJW_SHIFT 7 /* Synchronous jump width */ +#define XCAN_BTR_TS2_SHIFT 4 /* Time segment 2 */ +#define XCAN_BTR_SJW_SHIFT_CANFD 16 /* Synchronous jump width */ +#define XCAN_BTR_TS2_SHIFT_CANFD 8 /* Time segment 2 */ +#define XCAN_IDR_ID1_SHIFT 21 /* Standard Messg Identifier */ +#define XCAN_IDR_ID2_SHIFT 1 /* Extended Message Identifier */ +#define XCAN_DLCR_DLC_SHIFT 28 /* Data length code */ +#define XCAN_ESR_REC_SHIFT 8 /* Rx Error Count */ + +/* CAN frame length constants */ +#define XCAN_FRAME_MAX_DATA_LEN 8 +#define XCANFD_DW_BYTES 4 +#define XCAN_TIMEOUT (1 * HZ) + +/* TX-FIFO-empty interrupt available */ +#define XCAN_FLAG_TXFEMP 0x0001 +/* RX Match Not Finished interrupt available */ +#define XCAN_FLAG_RXMNF 0x0002 +/* Extended acceptance filters with control at 0xE0 */ +#define XCAN_FLAG_EXT_FILTERS 0x0004 +/* TX mailboxes instead of TX FIFO */ +#define XCAN_FLAG_TX_MAILBOXES 0x0008 +/* RX FIFO with each buffer in separate registers at 0x1100 + * instead of the regular FIFO at 0x50 + */ +#define XCAN_FLAG_RX_FIFO_MULTI 0x0010 +#define XCAN_FLAG_CANFD_2 0x0020 + +enum xcan_ip_type { + XAXI_CAN = 0, + XZYNQ_CANPS, + XAXI_CANFD, + XAXI_CANFD_2_0, +}; + +struct xcan_devtype_data { + enum xcan_ip_type cantype; + unsigned int flags; + const struct can_bittiming_const *bittiming_const; + const char *bus_clk_name; + unsigned int btr_ts2_shift; + unsigned int btr_sjw_shift; +}; + +/** + * struct xcan_priv - This definition define CAN driver instance + * @can: CAN private data structure. + * @tx_lock: Lock for synchronizing TX interrupt handling + * @tx_head: Tx CAN packets ready to send on the queue + * @tx_tail: Tx CAN packets successfully sended on the queue + * @tx_max: Maximum number packets the driver can send + * @napi: NAPI structure + * @read_reg: For reading data from CAN registers + * @write_reg: For writing data to CAN registers + * @dev: Network device data structure + * @reg_base: Ioremapped address to registers + * @irq_flags: For request_irq() + * @bus_clk: Pointer to struct clk + * @can_clk: Pointer to struct clk + * @devtype: Device type specific constants + */ +struct xcan_priv { + struct can_priv can; + spinlock_t tx_lock; /* Lock for synchronizing TX interrupt handling */ + unsigned int tx_head; + unsigned int tx_tail; + unsigned int tx_max; + struct napi_struct napi; + u32 (*read_reg)(const struct xcan_priv *priv, enum xcan_reg reg); + void (*write_reg)(const struct xcan_priv *priv, enum xcan_reg reg, + u32 val); + struct device *dev; + void __iomem *reg_base; + unsigned long irq_flags; + struct clk *bus_clk; + struct clk *can_clk; + struct xcan_devtype_data devtype; +}; + +/* CAN Bittiming constants as per Xilinx CAN specs */ +static const struct can_bittiming_const xcan_bittiming_const = { + .name = DRIVER_NAME, + .tseg1_min = 1, + .tseg1_max = 16, + .tseg2_min = 1, + .tseg2_max = 8, + .sjw_max = 4, + .brp_min = 1, + .brp_max = 256, + .brp_inc = 1, +}; + +/* AXI CANFD Arbitration Bittiming constants as per AXI CANFD 1.0 spec */ +static const struct can_bittiming_const xcan_bittiming_const_canfd = { + .name = DRIVER_NAME, + .tseg1_min = 1, + .tseg1_max = 64, + .tseg2_min = 1, + .tseg2_max = 16, + .sjw_max = 16, + .brp_min = 1, + .brp_max = 256, + .brp_inc = 1, +}; + +/* AXI CANFD Data Bittiming constants as per AXI CANFD 1.0 specs */ +static const struct can_bittiming_const xcan_data_bittiming_const_canfd = { + .name = DRIVER_NAME, + .tseg1_min = 1, + .tseg1_max = 16, + .tseg2_min = 1, + .tseg2_max = 8, + .sjw_max = 8, + .brp_min = 1, + .brp_max = 256, + .brp_inc = 1, +}; + +/* AXI CANFD 2.0 Arbitration Bittiming constants as per AXI CANFD 2.0 spec */ +static const struct can_bittiming_const xcan_bittiming_const_canfd2 = { + .name = DRIVER_NAME, + .tseg1_min = 1, + .tseg1_max = 256, + .tseg2_min = 1, + .tseg2_max = 128, + .sjw_max = 128, + .brp_min = 1, + .brp_max = 256, + .brp_inc = 1, +}; + +/* AXI CANFD 2.0 Data Bittiming constants as per AXI CANFD 2.0 spec */ +static const struct can_bittiming_const xcan_data_bittiming_const_canfd2 = { + .name = DRIVER_NAME, + .tseg1_min = 1, + .tseg1_max = 32, + .tseg2_min = 1, + .tseg2_max = 16, + .sjw_max = 16, + .brp_min = 1, + .brp_max = 256, + .brp_inc = 1, +}; + +/** + * xcan_write_reg_le - Write a value to the device register little endian + * @priv: Driver private data structure + * @reg: Register offset + * @val: Value to write at the Register offset + * + * Write data to the paricular CAN register + */ +static void xcan_write_reg_le(const struct xcan_priv *priv, enum xcan_reg reg, + u32 val) +{ + iowrite32(val, priv->reg_base + reg); +} + +/** + * xcan_read_reg_le - Read a value from the device register little endian + * @priv: Driver private data structure + * @reg: Register offset + * + * Read data from the particular CAN register + * Return: value read from the CAN register + */ +static u32 xcan_read_reg_le(const struct xcan_priv *priv, enum xcan_reg reg) +{ + return ioread32(priv->reg_base + reg); +} + +/** + * xcan_write_reg_be - Write a value to the device register big endian + * @priv: Driver private data structure + * @reg: Register offset + * @val: Value to write at the Register offset + * + * Write data to the paricular CAN register + */ +static void xcan_write_reg_be(const struct xcan_priv *priv, enum xcan_reg reg, + u32 val) +{ + iowrite32be(val, priv->reg_base + reg); +} + +/** + * xcan_read_reg_be - Read a value from the device register big endian + * @priv: Driver private data structure + * @reg: Register offset + * + * Read data from the particular CAN register + * Return: value read from the CAN register + */ +static u32 xcan_read_reg_be(const struct xcan_priv *priv, enum xcan_reg reg) +{ + return ioread32be(priv->reg_base + reg); +} + +/** + * xcan_rx_int_mask - Get the mask for the receive interrupt + * @priv: Driver private data structure + * + * Return: The receive interrupt mask used by the driver on this HW + */ +static u32 xcan_rx_int_mask(const struct xcan_priv *priv) +{ + /* RXNEMP is better suited for our use case as it cannot be cleared + * while the FIFO is non-empty, but CAN FD HW does not have it + */ + if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI) + return XCAN_IXR_RXOK_MASK; + else + return XCAN_IXR_RXNEMP_MASK; +} + +/** + * set_reset_mode - Resets the CAN device mode + * @ndev: Pointer to net_device structure + * + * This is the driver reset mode routine.The driver + * enters into configuration mode. + * + * Return: 0 on success and failure value on error + */ +static int set_reset_mode(struct net_device *ndev) +{ + struct xcan_priv *priv = netdev_priv(ndev); + unsigned long timeout; + + priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK); + + timeout = jiffies + XCAN_TIMEOUT; + while (!(priv->read_reg(priv, XCAN_SR_OFFSET) & XCAN_SR_CONFIG_MASK)) { + if (time_after(jiffies, timeout)) { + netdev_warn(ndev, "timed out for config mode\n"); + return -ETIMEDOUT; + } + usleep_range(500, 10000); + } + + /* reset clears FIFOs */ + priv->tx_head = 0; + priv->tx_tail = 0; + + return 0; +} + +/** + * xcan_set_bittiming - CAN set bit timing routine + * @ndev: Pointer to net_device structure + * + * This is the driver set bittiming routine. + * Return: 0 on success and failure value on error + */ +static int xcan_set_bittiming(struct net_device *ndev) +{ + struct xcan_priv *priv = netdev_priv(ndev); + struct can_bittiming *bt = &priv->can.bittiming; + struct can_bittiming *dbt = &priv->can.data_bittiming; + u32 btr0, btr1; + u32 is_config_mode; + + /* Check whether Xilinx CAN is in configuration mode. + * It cannot set bit timing if Xilinx CAN is not in configuration mode. + */ + is_config_mode = priv->read_reg(priv, XCAN_SR_OFFSET) & + XCAN_SR_CONFIG_MASK; + if (!is_config_mode) { + netdev_alert(ndev, + "BUG! Cannot set bittiming - CAN is not in config mode\n"); + return -EPERM; + } + + /* Setting Baud Rate prescalar value in BRPR Register */ + btr0 = (bt->brp - 1); + + /* Setting Time Segment 1 in BTR Register */ + btr1 = (bt->prop_seg + bt->phase_seg1 - 1); + + /* Setting Time Segment 2 in BTR Register */ + btr1 |= (bt->phase_seg2 - 1) << priv->devtype.btr_ts2_shift; + + /* Setting Synchronous jump width in BTR Register */ + btr1 |= (bt->sjw - 1) << priv->devtype.btr_sjw_shift; + + priv->write_reg(priv, XCAN_BRPR_OFFSET, btr0); + priv->write_reg(priv, XCAN_BTR_OFFSET, btr1); + + if (priv->devtype.cantype == XAXI_CANFD || + priv->devtype.cantype == XAXI_CANFD_2_0) { + /* Setting Baud Rate prescalar value in F_BRPR Register */ + btr0 = dbt->brp - 1; + + /* Setting Time Segment 1 in BTR Register */ + btr1 = dbt->prop_seg + dbt->phase_seg1 - 1; + + /* Setting Time Segment 2 in BTR Register */ + btr1 |= (dbt->phase_seg2 - 1) << priv->devtype.btr_ts2_shift; + + /* Setting Synchronous jump width in BTR Register */ + btr1 |= (dbt->sjw - 1) << priv->devtype.btr_sjw_shift; + + priv->write_reg(priv, XCAN_F_BRPR_OFFSET, btr0); + priv->write_reg(priv, XCAN_F_BTR_OFFSET, btr1); + } + + netdev_dbg(ndev, "BRPR=0x%08x, BTR=0x%08x\n", + priv->read_reg(priv, XCAN_BRPR_OFFSET), + priv->read_reg(priv, XCAN_BTR_OFFSET)); + + return 0; +} + +/** + * xcan_chip_start - This the drivers start routine + * @ndev: Pointer to net_device structure + * + * This is the drivers start routine. + * Based on the State of the CAN device it puts + * the CAN device into a proper mode. + * + * Return: 0 on success and failure value on error + */ +static int xcan_chip_start(struct net_device *ndev) +{ + struct xcan_priv *priv = netdev_priv(ndev); + u32 reg_msr; + int err; + u32 ier; + + /* Check if it is in reset mode */ + err = set_reset_mode(ndev); + if (err < 0) + return err; + + err = xcan_set_bittiming(ndev); + if (err < 0) + return err; + + /* Enable interrupts + * + * We enable the ERROR interrupt even with + * CAN_CTRLMODE_BERR_REPORTING disabled as there is no + * dedicated interrupt for a state change to + * ERROR_WARNING/ERROR_PASSIVE. + */ + ier = XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK | + XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK | + XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK | + XCAN_IXR_ARBLST_MASK | xcan_rx_int_mask(priv); + + if (priv->devtype.flags & XCAN_FLAG_RXMNF) + ier |= XCAN_IXR_RXMNF_MASK; + + priv->write_reg(priv, XCAN_IER_OFFSET, ier); + + /* Check whether it is loopback mode or normal mode */ + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) + reg_msr = XCAN_MSR_LBACK_MASK; + else + reg_msr = 0x0; + + /* enable the first extended filter, if any, as cores with extended + * filtering default to non-receipt if all filters are disabled + */ + if (priv->devtype.flags & XCAN_FLAG_EXT_FILTERS) + priv->write_reg(priv, XCAN_AFR_EXT_OFFSET, 0x00000001); + + priv->write_reg(priv, XCAN_MSR_OFFSET, reg_msr); + priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK); + + netdev_dbg(ndev, "status:#x%08x\n", + priv->read_reg(priv, XCAN_SR_OFFSET)); + + priv->can.state = CAN_STATE_ERROR_ACTIVE; + return 0; +} + +/** + * xcan_do_set_mode - This sets the mode of the driver + * @ndev: Pointer to net_device structure + * @mode: Tells the mode of the driver + * + * This check the drivers state and calls the + * the corresponding modes to set. + * + * Return: 0 on success and failure value on error + */ +static int xcan_do_set_mode(struct net_device *ndev, enum can_mode mode) +{ + int ret; + + switch (mode) { + case CAN_MODE_START: + ret = xcan_chip_start(ndev); + if (ret < 0) { + netdev_err(ndev, "xcan_chip_start failed!\n"); + return ret; + } + netif_wake_queue(ndev); + break; + default: + ret = -EOPNOTSUPP; + break; + } + + return ret; +} + +/** + * xcan_write_frame - Write a frame to HW + * @ndev: Pointer to net_device structure + * @skb: sk_buff pointer that contains data to be Txed + * @frame_offset: Register offset to write the frame to + */ +static void xcan_write_frame(struct net_device *ndev, struct sk_buff *skb, + int frame_offset) +{ + u32 id, dlc, data[2] = {0, 0}; + struct canfd_frame *cf = (struct canfd_frame *)skb->data; + u32 ramoff, dwindex = 0, i; + struct xcan_priv *priv = netdev_priv(ndev); + + /* Watch carefully on the bit sequence */ + if (cf->can_id & CAN_EFF_FLAG) { + /* Extended CAN ID format */ + id = ((cf->can_id & CAN_EFF_MASK) << XCAN_IDR_ID2_SHIFT) & + XCAN_IDR_ID2_MASK; + id |= (((cf->can_id & CAN_EFF_MASK) >> + (CAN_EFF_ID_BITS - CAN_SFF_ID_BITS)) << + XCAN_IDR_ID1_SHIFT) & XCAN_IDR_ID1_MASK; + + /* The substibute remote TX request bit should be "1" + * for extended frames as in the Xilinx CAN datasheet + */ + id |= XCAN_IDR_IDE_MASK | XCAN_IDR_SRR_MASK; + + if (cf->can_id & CAN_RTR_FLAG) + /* Extended frames remote TX request */ + id |= XCAN_IDR_RTR_MASK; + } else { + /* Standard CAN ID format */ + id = ((cf->can_id & CAN_SFF_MASK) << XCAN_IDR_ID1_SHIFT) & + XCAN_IDR_ID1_MASK; + + if (cf->can_id & CAN_RTR_FLAG) + /* Standard frames remote TX request */ + id |= XCAN_IDR_SRR_MASK; + } + + dlc = can_len2dlc(cf->len) << XCAN_DLCR_DLC_SHIFT; + if (can_is_canfd_skb(skb)) { + if (cf->flags & CANFD_BRS) + dlc |= XCAN_DLCR_BRS_MASK; + dlc |= XCAN_DLCR_EDL_MASK; + } + + if (!(priv->devtype.flags & XCAN_FLAG_TX_MAILBOXES) && + (priv->devtype.flags & XCAN_FLAG_TXFEMP)) + can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max); + else + can_put_echo_skb(skb, ndev, 0); + + priv->tx_head++; + + priv->write_reg(priv, XCAN_FRAME_ID_OFFSET(frame_offset), id); + /* If the CAN frame is RTR frame this write triggers transmission + * (not on CAN FD) + */ + priv->write_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_offset), dlc); + if (priv->devtype.cantype == XAXI_CANFD || + priv->devtype.cantype == XAXI_CANFD_2_0) { + for (i = 0; i < cf->len; i += 4) { + ramoff = XCANFD_FRAME_DW_OFFSET(frame_offset) + + (dwindex * XCANFD_DW_BYTES); + priv->write_reg(priv, ramoff, + be32_to_cpup((__be32 *)(cf->data + i))); + dwindex++; + } + } else { + if (cf->len > 0) + data[0] = be32_to_cpup((__be32 *)(cf->data + 0)); + if (cf->len > 4) + data[1] = be32_to_cpup((__be32 *)(cf->data + 4)); + + if (!(cf->can_id & CAN_RTR_FLAG)) { + priv->write_reg(priv, + XCAN_FRAME_DW1_OFFSET(frame_offset), + data[0]); + /* If the CAN frame is Standard/Extended frame this + * write triggers transmission (not on CAN FD) + */ + priv->write_reg(priv, + XCAN_FRAME_DW2_OFFSET(frame_offset), + data[1]); + } + } +} + +/** + * xcan_start_xmit_fifo - Starts the transmission (FIFO mode) + * @skb: sk_buff pointer that contains data to be Txed + * @ndev: Pointer to net_device structure + * + * Return: 0 on success, -ENOSPC if FIFO is full. + */ +static int xcan_start_xmit_fifo(struct sk_buff *skb, struct net_device *ndev) +{ + struct xcan_priv *priv = netdev_priv(ndev); + unsigned long flags; + + /* Check if the TX buffer is full */ + if (unlikely(priv->read_reg(priv, XCAN_SR_OFFSET) & + XCAN_SR_TXFLL_MASK)) + return -ENOSPC; + + spin_lock_irqsave(&priv->tx_lock, flags); + + xcan_write_frame(ndev, skb, XCAN_TXFIFO_OFFSET); + + /* Clear TX-FIFO-empty interrupt for xcan_tx_interrupt() */ + if (priv->tx_max > 1) + priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXFEMP_MASK); + + /* Check if the TX buffer is full */ + if ((priv->tx_head - priv->tx_tail) == priv->tx_max) + netif_stop_queue(ndev); + + spin_unlock_irqrestore(&priv->tx_lock, flags); + + return 0; +} + +/** + * xcan_start_xmit_mailbox - Starts the transmission (mailbox mode) + * @skb: sk_buff pointer that contains data to be Txed + * @ndev: Pointer to net_device structure + * + * Return: 0 on success, -ENOSPC if there is no space + */ +static int xcan_start_xmit_mailbox(struct sk_buff *skb, struct net_device *ndev) +{ + struct xcan_priv *priv = netdev_priv(ndev); + unsigned long flags; + + if (unlikely(priv->read_reg(priv, XCAN_TRR_OFFSET) & + BIT(XCAN_TX_MAILBOX_IDX))) + return -ENOSPC; + + spin_lock_irqsave(&priv->tx_lock, flags); + + xcan_write_frame(ndev, skb, + XCAN_TXMSG_FRAME_OFFSET(XCAN_TX_MAILBOX_IDX)); + + /* Mark buffer as ready for transmit */ + priv->write_reg(priv, XCAN_TRR_OFFSET, BIT(XCAN_TX_MAILBOX_IDX)); + + netif_stop_queue(ndev); + + spin_unlock_irqrestore(&priv->tx_lock, flags); + + return 0; +} + +/** + * xcan_start_xmit - Starts the transmission + * @skb: sk_buff pointer that contains data to be Txed + * @ndev: Pointer to net_device structure + * + * This function is invoked from upper layers to initiate transmission. + * + * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY when the tx queue is full + */ +static netdev_tx_t xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev) +{ + struct xcan_priv *priv = netdev_priv(ndev); + int ret; + + if (can_dropped_invalid_skb(ndev, skb)) + return NETDEV_TX_OK; + + if (priv->devtype.flags & XCAN_FLAG_TX_MAILBOXES) + ret = xcan_start_xmit_mailbox(skb, ndev); + else + ret = xcan_start_xmit_fifo(skb, ndev); + + if (ret < 0) { + netdev_err(ndev, "BUG!, TX full when queue awake!\n"); + netif_stop_queue(ndev); + return NETDEV_TX_BUSY; + } + + return NETDEV_TX_OK; +} + +/** + * xcan_rx - Is called from CAN isr to complete the received + * frame processing + * @ndev: Pointer to net_device structure + * @frame_base: Register offset to the frame to be read + * + * This function is invoked from the CAN isr(poll) to process the Rx frames. It + * does minimal processing and invokes "netif_receive_skb" to complete further + * processing. + * Return: 1 on success and 0 on failure. + */ +static int xcan_rx(struct net_device *ndev, int frame_base) +{ + struct xcan_priv *priv = netdev_priv(ndev); + struct net_device_stats *stats = &ndev->stats; + struct can_frame *cf; + struct sk_buff *skb; + u32 id_xcan, dlc, data[2] = {0, 0}; + + skb = alloc_can_skb(ndev, &cf); + if (unlikely(!skb)) { + stats->rx_dropped++; + return 0; + } + + /* Read a frame from Xilinx zynq CANPS */ + id_xcan = priv->read_reg(priv, XCAN_FRAME_ID_OFFSET(frame_base)); + dlc = priv->read_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_base)) >> + XCAN_DLCR_DLC_SHIFT; + + /* Change Xilinx CAN data length format to socketCAN data format */ + cf->can_dlc = get_can_dlc(dlc); + + /* Change Xilinx CAN ID format to socketCAN ID format */ + if (id_xcan & XCAN_IDR_IDE_MASK) { + /* The received frame is an Extended format frame */ + cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >> 3; + cf->can_id |= (id_xcan & XCAN_IDR_ID2_MASK) >> + XCAN_IDR_ID2_SHIFT; + cf->can_id |= CAN_EFF_FLAG; + if (id_xcan & XCAN_IDR_RTR_MASK) + cf->can_id |= CAN_RTR_FLAG; + } else { + /* The received frame is a standard format frame */ + cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >> + XCAN_IDR_ID1_SHIFT; + if (id_xcan & XCAN_IDR_SRR_MASK) + cf->can_id |= CAN_RTR_FLAG; + } + + /* DW1/DW2 must always be read to remove message from RXFIFO */ + data[0] = priv->read_reg(priv, XCAN_FRAME_DW1_OFFSET(frame_base)); + data[1] = priv->read_reg(priv, XCAN_FRAME_DW2_OFFSET(frame_base)); + + if (!(cf->can_id & CAN_RTR_FLAG)) { + /* Change Xilinx CAN data format to socketCAN data format */ + if (cf->can_dlc > 0) + *(__be32 *)(cf->data) = cpu_to_be32(data[0]); + if (cf->can_dlc > 4) + *(__be32 *)(cf->data + 4) = cpu_to_be32(data[1]); + } + + stats->rx_bytes += cf->can_dlc; + stats->rx_packets++; + netif_receive_skb(skb); + + return 1; +} + +/** + * xcanfd_rx - Is called from CAN isr to complete the received + * frame processing + * @ndev: Pointer to net_device structure + * @frame_base: Register offset to the frame to be read + * + * This function is invoked from the CAN isr(poll) to process the Rx frames. It + * does minimal processing and invokes "netif_receive_skb" to complete further + * processing. + * Return: 1 on success and 0 on failure. + */ +static int xcanfd_rx(struct net_device *ndev, int frame_base) +{ + struct xcan_priv *priv = netdev_priv(ndev); + struct net_device_stats *stats = &ndev->stats; + struct canfd_frame *cf; + struct sk_buff *skb; + u32 id_xcan, dlc, data[2] = {0, 0}, dwindex = 0, i, dw_offset; + + id_xcan = priv->read_reg(priv, XCAN_FRAME_ID_OFFSET(frame_base)); + dlc = priv->read_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_base)); + if (dlc & XCAN_DLCR_EDL_MASK) + skb = alloc_canfd_skb(ndev, &cf); + else + skb = alloc_can_skb(ndev, (struct can_frame **)&cf); + + if (unlikely(!skb)) { + stats->rx_dropped++; + return 0; + } + + /* Change Xilinx CANFD data length format to socketCAN data + * format + */ + if (dlc & XCAN_DLCR_EDL_MASK) + cf->len = can_dlc2len((dlc & XCAN_DLCR_DLC_MASK) >> + XCAN_DLCR_DLC_SHIFT); + else + cf->len = get_can_dlc((dlc & XCAN_DLCR_DLC_MASK) >> + XCAN_DLCR_DLC_SHIFT); + + /* Change Xilinx CAN ID format to socketCAN ID format */ + if (id_xcan & XCAN_IDR_IDE_MASK) { + /* The received frame is an Extended format frame */ + cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >> 3; + cf->can_id |= (id_xcan & XCAN_IDR_ID2_MASK) >> + XCAN_IDR_ID2_SHIFT; + cf->can_id |= CAN_EFF_FLAG; + if (id_xcan & XCAN_IDR_RTR_MASK) + cf->can_id |= CAN_RTR_FLAG; + } else { + /* The received frame is a standard format frame */ + cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >> + XCAN_IDR_ID1_SHIFT; + if (!(dlc & XCAN_DLCR_EDL_MASK) && (id_xcan & + XCAN_IDR_SRR_MASK)) + cf->can_id |= CAN_RTR_FLAG; + } + + /* Check the frame received is FD or not*/ + if (dlc & XCAN_DLCR_EDL_MASK) { + for (i = 0; i < cf->len; i += 4) { + dw_offset = XCANFD_FRAME_DW_OFFSET(frame_base) + + (dwindex * XCANFD_DW_BYTES); + data[0] = priv->read_reg(priv, dw_offset); + *(__be32 *)(cf->data + i) = cpu_to_be32(data[0]); + dwindex++; + } + } else { + for (i = 0; i < cf->len; i += 4) { + dw_offset = XCANFD_FRAME_DW_OFFSET(frame_base); + data[0] = priv->read_reg(priv, dw_offset + i); + *(__be32 *)(cf->data + i) = cpu_to_be32(data[0]); + } + } + stats->rx_bytes += cf->len; + stats->rx_packets++; + netif_receive_skb(skb); + + return 1; +} + +/** + * xcan_current_error_state - Get current error state from HW + * @ndev: Pointer to net_device structure + * + * Checks the current CAN error state from the HW. Note that this + * only checks for ERROR_PASSIVE and ERROR_WARNING. + * + * Return: + * ERROR_PASSIVE or ERROR_WARNING if either is active, ERROR_ACTIVE + * otherwise. + */ +static enum can_state xcan_current_error_state(struct net_device *ndev) +{ + struct xcan_priv *priv = netdev_priv(ndev); + u32 status = priv->read_reg(priv, XCAN_SR_OFFSET); + + if ((status & XCAN_SR_ESTAT_MASK) == XCAN_SR_ESTAT_MASK) + return CAN_STATE_ERROR_PASSIVE; + else if (status & XCAN_SR_ERRWRN_MASK) + return CAN_STATE_ERROR_WARNING; + else + return CAN_STATE_ERROR_ACTIVE; +} + +/** + * xcan_set_error_state - Set new CAN error state + * @ndev: Pointer to net_device structure + * @new_state: The new CAN state to be set + * @cf: Error frame to be populated or NULL + * + * Set new CAN error state for the device, updating statistics and + * populating the error frame if given. + */ +static void xcan_set_error_state(struct net_device *ndev, + enum can_state new_state, + struct can_frame *cf) +{ + struct xcan_priv *priv = netdev_priv(ndev); + u32 ecr = priv->read_reg(priv, XCAN_ECR_OFFSET); + u32 txerr = ecr & XCAN_ECR_TEC_MASK; + u32 rxerr = (ecr & XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT; + enum can_state tx_state = txerr >= rxerr ? new_state : 0; + enum can_state rx_state = txerr <= rxerr ? new_state : 0; + + /* non-ERROR states are handled elsewhere */ + if (WARN_ON(new_state > CAN_STATE_ERROR_PASSIVE)) + return; + + can_change_state(ndev, cf, tx_state, rx_state); + + if (cf) { + cf->data[6] = txerr; + cf->data[7] = rxerr; + } +} + +/** + * xcan_update_error_state_after_rxtx - Update CAN error state after RX/TX + * @ndev: Pointer to net_device structure + * + * If the device is in a ERROR-WARNING or ERROR-PASSIVE state, check if + * the performed RX/TX has caused it to drop to a lesser state and set + * the interface state accordingly. + */ +static void xcan_update_error_state_after_rxtx(struct net_device *ndev) +{ + struct xcan_priv *priv = netdev_priv(ndev); + enum can_state old_state = priv->can.state; + enum can_state new_state; + + /* changing error state due to successful frame RX/TX can only + * occur from these states + */ + if (old_state != CAN_STATE_ERROR_WARNING && + old_state != CAN_STATE_ERROR_PASSIVE) + return; + + new_state = xcan_current_error_state(ndev); + + if (new_state != old_state) { + struct sk_buff *skb; + struct can_frame *cf; + + skb = alloc_can_err_skb(ndev, &cf); + + xcan_set_error_state(ndev, new_state, skb ? cf : NULL); + + if (skb) { + struct net_device_stats *stats = &ndev->stats; + + stats->rx_packets++; + stats->rx_bytes += cf->can_dlc; + netif_rx(skb); + } + } +} + +/** + * xcan_err_interrupt - error frame Isr + * @ndev: net_device pointer + * @isr: interrupt status register value + * + * This is the CAN error interrupt and it will + * check the the type of error and forward the error + * frame to upper layers. + */ +static void xcan_err_interrupt(struct net_device *ndev, u32 isr) +{ + struct xcan_priv *priv = netdev_priv(ndev); + struct net_device_stats *stats = &ndev->stats; + struct can_frame cf = { }; + u32 err_status; + + err_status = priv->read_reg(priv, XCAN_ESR_OFFSET); + priv->write_reg(priv, XCAN_ESR_OFFSET, err_status); + + if (isr & XCAN_IXR_BSOFF_MASK) { + priv->can.state = CAN_STATE_BUS_OFF; + priv->can.can_stats.bus_off++; + /* Leave device in Config Mode in bus-off state */ + priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK); + can_bus_off(ndev); + cf.can_id |= CAN_ERR_BUSOFF; + } else { + enum can_state new_state = xcan_current_error_state(ndev); + + if (new_state != priv->can.state) + xcan_set_error_state(ndev, new_state, &cf); + } + + /* Check for Arbitration lost interrupt */ + if (isr & XCAN_IXR_ARBLST_MASK) { + priv->can.can_stats.arbitration_lost++; + cf.can_id |= CAN_ERR_LOSTARB; + cf.data[0] = CAN_ERR_LOSTARB_UNSPEC; + } + + /* Check for RX FIFO Overflow interrupt */ + if (isr & XCAN_IXR_RXOFLW_MASK) { + stats->rx_over_errors++; + stats->rx_errors++; + cf.can_id |= CAN_ERR_CRTL; + cf.data[1] |= CAN_ERR_CRTL_RX_OVERFLOW; + } + + /* Check for RX Match Not Finished interrupt */ + if (isr & XCAN_IXR_RXMNF_MASK) { + stats->rx_dropped++; + stats->rx_errors++; + netdev_err(ndev, "RX match not finished, frame discarded\n"); + cf.can_id |= CAN_ERR_CRTL; + cf.data[1] |= CAN_ERR_CRTL_UNSPEC; + } + + /* Check for error interrupt */ + if (isr & XCAN_IXR_ERROR_MASK) { + bool berr_reporting = false; + + if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) { + berr_reporting = true; + cf.can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; + } + + /* Check for Ack error interrupt */ + if (err_status & XCAN_ESR_ACKER_MASK) { + stats->tx_errors++; + if (berr_reporting) { + cf.can_id |= CAN_ERR_ACK; + cf.data[3] = CAN_ERR_PROT_LOC_ACK; + } + } + + /* Check for Bit error interrupt */ + if (err_status & XCAN_ESR_BERR_MASK) { + stats->tx_errors++; + if (berr_reporting) { + cf.can_id |= CAN_ERR_PROT; + cf.data[2] = CAN_ERR_PROT_BIT; + } + } + + /* Check for Stuff error interrupt */ + if (err_status & XCAN_ESR_STER_MASK) { + stats->rx_errors++; + if (berr_reporting) { + cf.can_id |= CAN_ERR_PROT; + cf.data[2] = CAN_ERR_PROT_STUFF; + } + } + + /* Check for Form error interrupt */ + if (err_status & XCAN_ESR_FMER_MASK) { + stats->rx_errors++; + if (berr_reporting) { + cf.can_id |= CAN_ERR_PROT; + cf.data[2] = CAN_ERR_PROT_FORM; + } + } + + /* Check for CRC error interrupt */ + if (err_status & XCAN_ESR_CRCER_MASK) { + stats->rx_errors++; + if (berr_reporting) { + cf.can_id |= CAN_ERR_PROT; + cf.data[3] = CAN_ERR_PROT_LOC_CRC_SEQ; + } + } + priv->can.can_stats.bus_error++; + } + + if (cf.can_id) { + struct can_frame *skb_cf; + struct sk_buff *skb = alloc_can_err_skb(ndev, &skb_cf); + + if (skb) { + skb_cf->can_id |= cf.can_id; + memcpy(skb_cf->data, cf.data, CAN_ERR_DLC); + stats->rx_packets++; + stats->rx_bytes += CAN_ERR_DLC; + netif_rx(skb); + } + } + + netdev_dbg(ndev, "%s: error status register:0x%x\n", + __func__, priv->read_reg(priv, XCAN_ESR_OFFSET)); +} + +/** + * xcan_state_interrupt - It will check the state of the CAN device + * @ndev: net_device pointer + * @isr: interrupt status register value + * + * This will checks the state of the CAN device + * and puts the device into appropriate state. + */ +static void xcan_state_interrupt(struct net_device *ndev, u32 isr) +{ + struct xcan_priv *priv = netdev_priv(ndev); + + /* Check for Sleep interrupt if set put CAN device in sleep state */ + if (isr & XCAN_IXR_SLP_MASK) + priv->can.state = CAN_STATE_SLEEPING; + + /* Check for Wake up interrupt if set put CAN device in Active state */ + if (isr & XCAN_IXR_WKUP_MASK) + priv->can.state = CAN_STATE_ERROR_ACTIVE; +} + +/** + * xcan_rx_fifo_get_next_frame - Get register offset of next RX frame + * @priv: Driver private data structure + * + * Return: Register offset of the next frame in RX FIFO. + */ +static int xcan_rx_fifo_get_next_frame(struct xcan_priv *priv) +{ + int offset; + + if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI) { + u32 fsr, mask; + + /* clear RXOK before the is-empty check so that any newly + * received frame will reassert it without a race + */ + priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_RXOK_MASK); + + fsr = priv->read_reg(priv, XCAN_FSR_OFFSET); + + /* check if RX FIFO is empty */ + if (priv->devtype.flags & XCAN_FLAG_CANFD_2) + mask = XCAN_2_FSR_FL_MASK; + else + mask = XCAN_FSR_FL_MASK; + + if (!(fsr & mask)) + return -ENOENT; + + if (priv->devtype.flags & XCAN_FLAG_CANFD_2) + offset = + XCAN_RXMSG_2_FRAME_OFFSET(fsr & XCAN_2_FSR_RI_MASK); + else + offset = + XCAN_RXMSG_FRAME_OFFSET(fsr & XCAN_FSR_RI_MASK); + + } else { + /* check if RX FIFO is empty */ + if (!(priv->read_reg(priv, XCAN_ISR_OFFSET) & + XCAN_IXR_RXNEMP_MASK)) + return -ENOENT; + + /* frames are read from a static offset */ + offset = XCAN_RXFIFO_OFFSET; + } + + return offset; +} + +/** + * xcan_rx_poll - Poll routine for rx packets (NAPI) + * @napi: napi structure pointer + * @quota: Max number of rx packets to be processed. + * + * This is the poll routine for rx part. + * It will process the packets maximux quota value. + * + * Return: number of packets received + */ +static int xcan_rx_poll(struct napi_struct *napi, int quota) +{ + struct net_device *ndev = napi->dev; + struct xcan_priv *priv = netdev_priv(ndev); + u32 ier; + int work_done = 0; + int frame_offset; + + while ((frame_offset = xcan_rx_fifo_get_next_frame(priv)) >= 0 && + (work_done < quota)) { + if (xcan_rx_int_mask(priv) & XCAN_IXR_RXOK_MASK) + work_done += xcanfd_rx(ndev, frame_offset); + else + work_done += xcan_rx(ndev, frame_offset); + + if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI) + /* increment read index */ + priv->write_reg(priv, XCAN_FSR_OFFSET, + XCAN_FSR_IRI_MASK); + else + /* clear rx-not-empty (will actually clear only if + * empty) + */ + priv->write_reg(priv, XCAN_ICR_OFFSET, + XCAN_IXR_RXNEMP_MASK); + } + + if (work_done) { + can_led_event(ndev, CAN_LED_EVENT_RX); + xcan_update_error_state_after_rxtx(ndev); + } + + if (work_done < quota) { + napi_complete_done(napi, work_done); + ier = priv->read_reg(priv, XCAN_IER_OFFSET); + ier |= xcan_rx_int_mask(priv); + priv->write_reg(priv, XCAN_IER_OFFSET, ier); + } + return work_done; +} + +/** + * xcan_tx_interrupt - Tx Done Isr + * @ndev: net_device pointer + * @isr: Interrupt status register value + */ +static void xcan_tx_interrupt(struct net_device *ndev, u32 isr) +{ + struct xcan_priv *priv = netdev_priv(ndev); + struct net_device_stats *stats = &ndev->stats; + unsigned int frames_in_fifo; + int frames_sent = 1; /* TXOK => at least 1 frame was sent */ + unsigned long flags; + int retries = 0; + + /* Synchronize with xmit as we need to know the exact number + * of frames in the FIFO to stay in sync due to the TXFEMP + * handling. + * This also prevents a race between netif_wake_queue() and + * netif_stop_queue(). + */ + spin_lock_irqsave(&priv->tx_lock, flags); + + frames_in_fifo = priv->tx_head - priv->tx_tail; + + if (WARN_ON_ONCE(frames_in_fifo == 0)) { + /* clear TXOK anyway to avoid getting back here */ + priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK); + spin_unlock_irqrestore(&priv->tx_lock, flags); + return; + } + + /* Check if 2 frames were sent (TXOK only means that at least 1 + * frame was sent). + */ + if (frames_in_fifo > 1) { + WARN_ON(frames_in_fifo > priv->tx_max); + + /* Synchronize TXOK and isr so that after the loop: + * (1) isr variable is up-to-date at least up to TXOK clear + * time. This avoids us clearing a TXOK of a second frame + * but not noticing that the FIFO is now empty and thus + * marking only a single frame as sent. + * (2) No TXOK is left. Having one could mean leaving a + * stray TXOK as we might process the associated frame + * via TXFEMP handling as we read TXFEMP *after* TXOK + * clear to satisfy (1). + */ + while ((isr & XCAN_IXR_TXOK_MASK) && + !WARN_ON(++retries == 100)) { + priv->write_reg(priv, XCAN_ICR_OFFSET, + XCAN_IXR_TXOK_MASK); + isr = priv->read_reg(priv, XCAN_ISR_OFFSET); + } + + if (isr & XCAN_IXR_TXFEMP_MASK) { + /* nothing in FIFO anymore */ + frames_sent = frames_in_fifo; + } + } else { + /* single frame in fifo, just clear TXOK */ + priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK); + } + + while (frames_sent--) { + stats->tx_bytes += can_get_echo_skb(ndev, priv->tx_tail % + priv->tx_max); + priv->tx_tail++; + stats->tx_packets++; + } + + netif_wake_queue(ndev); + + spin_unlock_irqrestore(&priv->tx_lock, flags); + + can_led_event(ndev, CAN_LED_EVENT_TX); + xcan_update_error_state_after_rxtx(ndev); +} + +/** + * xcan_interrupt - CAN Isr + * @irq: irq number + * @dev_id: device id pointer + * + * This is the xilinx CAN Isr. It checks for the type of interrupt + * and invokes the corresponding ISR. + * + * Return: + * IRQ_NONE - If CAN device is in sleep mode, IRQ_HANDLED otherwise + */ +static irqreturn_t xcan_interrupt(int irq, void *dev_id) +{ + struct net_device *ndev = (struct net_device *)dev_id; + struct xcan_priv *priv = netdev_priv(ndev); + u32 isr, ier; + u32 isr_errors; + u32 rx_int_mask = xcan_rx_int_mask(priv); + + /* Get the interrupt status from Xilinx CAN */ + isr = priv->read_reg(priv, XCAN_ISR_OFFSET); + if (!isr) + return IRQ_NONE; + + /* Check for the type of interrupt and Processing it */ + if (isr & (XCAN_IXR_SLP_MASK | XCAN_IXR_WKUP_MASK)) { + priv->write_reg(priv, XCAN_ICR_OFFSET, (XCAN_IXR_SLP_MASK | + XCAN_IXR_WKUP_MASK)); + xcan_state_interrupt(ndev, isr); + } + + /* Check for Tx interrupt and Processing it */ + if (isr & XCAN_IXR_TXOK_MASK) + xcan_tx_interrupt(ndev, isr); + + /* Check for the type of error interrupt and Processing it */ + isr_errors = isr & (XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK | + XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK | + XCAN_IXR_RXMNF_MASK); + if (isr_errors) { + priv->write_reg(priv, XCAN_ICR_OFFSET, isr_errors); + xcan_err_interrupt(ndev, isr); + } + + /* Check for the type of receive interrupt and Processing it */ + if (isr & rx_int_mask) { + ier = priv->read_reg(priv, XCAN_IER_OFFSET); + ier &= ~rx_int_mask; + priv->write_reg(priv, XCAN_IER_OFFSET, ier); + napi_schedule(&priv->napi); + } + return IRQ_HANDLED; +} + +/** + * xcan_chip_stop - Driver stop routine + * @ndev: Pointer to net_device structure + * + * This is the drivers stop routine. It will disable the + * interrupts and put the device into configuration mode. + */ +static void xcan_chip_stop(struct net_device *ndev) +{ + struct xcan_priv *priv = netdev_priv(ndev); + int ret; + + /* Disable interrupts and leave the can in configuration mode */ + ret = set_reset_mode(ndev); + if (ret < 0) + netdev_dbg(ndev, "set_reset_mode() Failed\n"); + + priv->can.state = CAN_STATE_STOPPED; +} + +/** + * xcan_open - Driver open routine + * @ndev: Pointer to net_device structure + * + * This is the driver open routine. + * Return: 0 on success and failure value on error + */ +static int xcan_open(struct net_device *ndev) +{ + struct xcan_priv *priv = netdev_priv(ndev); + int ret; + + ret = pm_runtime_get_sync(priv->dev); + if (ret < 0) { + netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n", + __func__, ret); + goto err; + } + + ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags, + ndev->name, ndev); + if (ret < 0) { + netdev_err(ndev, "irq allocation for CAN failed\n"); + goto err; + } + + /* Set chip into reset mode */ + ret = set_reset_mode(ndev); + if (ret < 0) { + netdev_err(ndev, "mode resetting failed!\n"); + goto err_irq; + } + + /* Common open */ + ret = open_candev(ndev); + if (ret) + goto err_irq; + + ret = xcan_chip_start(ndev); + if (ret < 0) { + netdev_err(ndev, "xcan_chip_start failed!\n"); + goto err_candev; + } + + can_led_event(ndev, CAN_LED_EVENT_OPEN); + napi_enable(&priv->napi); + netif_start_queue(ndev); + + return 0; + +err_candev: + close_candev(ndev); +err_irq: + free_irq(ndev->irq, ndev); +err: + pm_runtime_put(priv->dev); + + return ret; +} + +/** + * xcan_close - Driver close routine + * @ndev: Pointer to net_device structure + * + * Return: 0 always + */ +static int xcan_close(struct net_device *ndev) +{ + struct xcan_priv *priv = netdev_priv(ndev); + + netif_stop_queue(ndev); + napi_disable(&priv->napi); + xcan_chip_stop(ndev); + free_irq(ndev->irq, ndev); + close_candev(ndev); + + can_led_event(ndev, CAN_LED_EVENT_STOP); + pm_runtime_put(priv->dev); + + return 0; +} + +/** + * xcan_get_berr_counter - error counter routine + * @ndev: Pointer to net_device structure + * @bec: Pointer to can_berr_counter structure + * + * This is the driver error counter routine. + * Return: 0 on success and failure value on error + */ +static int xcan_get_berr_counter(const struct net_device *ndev, + struct can_berr_counter *bec) +{ + struct xcan_priv *priv = netdev_priv(ndev); + int ret; + + ret = pm_runtime_get_sync(priv->dev); + if (ret < 0) { + netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n", + __func__, ret); + pm_runtime_put(priv->dev); + return ret; + } + + bec->txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK; + bec->rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) & + XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT); + + pm_runtime_put(priv->dev); + + return 0; +} + +static const struct net_device_ops xcan_netdev_ops = { + .ndo_open = xcan_open, + .ndo_stop = xcan_close, + .ndo_start_xmit = xcan_start_xmit, + .ndo_change_mtu = can_change_mtu, +}; + +/** + * xcan_suspend - Suspend method for the driver + * @dev: Address of the device structure + * + * Put the driver into low power mode. + * Return: 0 on success and failure value on error + */ +static int __maybe_unused xcan_suspend(struct device *dev) +{ + struct net_device *ndev = dev_get_drvdata(dev); + + if (netif_running(ndev)) { + netif_stop_queue(ndev); + netif_device_detach(ndev); + xcan_chip_stop(ndev); + } + + return pm_runtime_force_suspend(dev); +} + +/** + * xcan_resume - Resume from suspend + * @dev: Address of the device structure + * + * Resume operation after suspend. + * Return: 0 on success and failure value on error + */ +static int __maybe_unused xcan_resume(struct device *dev) +{ + struct net_device *ndev = dev_get_drvdata(dev); + int ret; + + ret = pm_runtime_force_resume(dev); + if (ret) { + dev_err(dev, "pm_runtime_force_resume failed on resume\n"); + return ret; + } + + if (netif_running(ndev)) { + ret = xcan_chip_start(ndev); + if (ret) { + dev_err(dev, "xcan_chip_start failed on resume\n"); + return ret; + } + + netif_device_attach(ndev); + netif_start_queue(ndev); + } + + return 0; +} + +/** + * xcan_runtime_suspend - Runtime suspend method for the driver + * @dev: Address of the device structure + * + * Put the driver into low power mode. + * Return: 0 always + */ +static int __maybe_unused xcan_runtime_suspend(struct device *dev) +{ + struct net_device *ndev = dev_get_drvdata(dev); + struct xcan_priv *priv = netdev_priv(ndev); + + clk_disable_unprepare(priv->bus_clk); + clk_disable_unprepare(priv->can_clk); + + return 0; +} + +/** + * xcan_runtime_resume - Runtime resume from suspend + * @dev: Address of the device structure + * + * Resume operation after suspend. + * Return: 0 on success and failure value on error + */ +static int __maybe_unused xcan_runtime_resume(struct device *dev) +{ + struct net_device *ndev = dev_get_drvdata(dev); + struct xcan_priv *priv = netdev_priv(ndev); + int ret; + + ret = clk_prepare_enable(priv->bus_clk); + if (ret) { + dev_err(dev, "Cannot enable clock.\n"); + return ret; + } + ret = clk_prepare_enable(priv->can_clk); + if (ret) { + dev_err(dev, "Cannot enable clock.\n"); + clk_disable_unprepare(priv->bus_clk); + return ret; + } + + return 0; +} + +static const struct dev_pm_ops xcan_dev_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(xcan_suspend, xcan_resume) + SET_RUNTIME_PM_OPS(xcan_runtime_suspend, xcan_runtime_resume, NULL) +}; + +static const struct xcan_devtype_data xcan_zynq_data = { + .cantype = XZYNQ_CANPS, + .flags = XCAN_FLAG_TXFEMP, + .bittiming_const = &xcan_bittiming_const, + .btr_ts2_shift = XCAN_BTR_TS2_SHIFT, + .btr_sjw_shift = XCAN_BTR_SJW_SHIFT, + .bus_clk_name = "pclk", +}; + +static const struct xcan_devtype_data xcan_axi_data = { + .cantype = XAXI_CAN, + .bittiming_const = &xcan_bittiming_const, + .btr_ts2_shift = XCAN_BTR_TS2_SHIFT, + .btr_sjw_shift = XCAN_BTR_SJW_SHIFT, + .bus_clk_name = "s_axi_aclk", +}; + +static const struct xcan_devtype_data xcan_canfd_data = { + .cantype = XAXI_CANFD, + .flags = XCAN_FLAG_EXT_FILTERS | + XCAN_FLAG_RXMNF | + XCAN_FLAG_TX_MAILBOXES | + XCAN_FLAG_RX_FIFO_MULTI, + .bittiming_const = &xcan_bittiming_const_canfd, + .btr_ts2_shift = XCAN_BTR_TS2_SHIFT_CANFD, + .btr_sjw_shift = XCAN_BTR_SJW_SHIFT_CANFD, + .bus_clk_name = "s_axi_aclk", +}; + +static const struct xcan_devtype_data xcan_canfd2_data = { + .cantype = XAXI_CANFD_2_0, + .flags = XCAN_FLAG_EXT_FILTERS | + XCAN_FLAG_RXMNF | + XCAN_FLAG_TX_MAILBOXES | + XCAN_FLAG_CANFD_2 | + XCAN_FLAG_RX_FIFO_MULTI, + .bittiming_const = &xcan_bittiming_const_canfd2, + .btr_ts2_shift = XCAN_BTR_TS2_SHIFT_CANFD, + .btr_sjw_shift = XCAN_BTR_SJW_SHIFT_CANFD, + .bus_clk_name = "s_axi_aclk", +}; + +/* Match table for OF platform binding */ +static const struct of_device_id xcan_of_match[] = { + { .compatible = "xlnx,zynq-can-1.0", .data = &xcan_zynq_data }, + { .compatible = "xlnx,axi-can-1.00.a", .data = &xcan_axi_data }, + { .compatible = "xlnx,canfd-1.0", .data = &xcan_canfd_data }, + { .compatible = "xlnx,canfd-2.0", .data = &xcan_canfd2_data }, + { /* end of list */ }, +}; +MODULE_DEVICE_TABLE(of, xcan_of_match); + +/** + * xcan_probe - Platform registration call + * @pdev: Handle to the platform device structure + * + * This function does all the memory allocation and registration for the CAN + * device. + * + * Return: 0 on success and failure value on error + */ +static int xcan_probe(struct platform_device *pdev) +{ + struct net_device *ndev; + struct xcan_priv *priv; + const struct of_device_id *of_id; + const struct xcan_devtype_data *devtype = &xcan_axi_data; + void __iomem *addr; + int ret; + int rx_max, tx_max; + u32 hw_tx_max = 0, hw_rx_max = 0; + const char *hw_tx_max_property; + + /* Get the virtual base address for the device */ + addr = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(addr)) { + ret = PTR_ERR(addr); + goto err; + } + + of_id = of_match_device(xcan_of_match, &pdev->dev); + if (of_id && of_id->data) + devtype = of_id->data; + + hw_tx_max_property = devtype->flags & XCAN_FLAG_TX_MAILBOXES ? + "tx-mailbox-count" : "tx-fifo-depth"; + + ret = of_property_read_u32(pdev->dev.of_node, hw_tx_max_property, + &hw_tx_max); + if (ret < 0) { + dev_err(&pdev->dev, "missing %s property\n", + hw_tx_max_property); + goto err; + } + + ret = of_property_read_u32(pdev->dev.of_node, "rx-fifo-depth", + &hw_rx_max); + if (ret < 0) { + dev_err(&pdev->dev, + "missing rx-fifo-depth property (mailbox mode is not supported)\n"); + goto err; + } + + /* With TX FIFO: + * + * There is no way to directly figure out how many frames have been + * sent when the TXOK interrupt is processed. If TXFEMP + * is supported, we can have 2 frames in the FIFO and use TXFEMP + * to determine if 1 or 2 frames have been sent. + * Theoretically we should be able to use TXFWMEMP to determine up + * to 3 frames, but it seems that after putting a second frame in the + * FIFO, with watermark at 2 frames, it can happen that TXFWMEMP (less + * than 2 frames in FIFO) is set anyway with no TXOK (a frame was + * sent), which is not a sensible state - possibly TXFWMEMP is not + * completely synchronized with the rest of the bits? + * + * With TX mailboxes: + * + * HW sends frames in CAN ID priority order. To preserve FIFO ordering + * we submit frames one at a time. + */ + if (!(devtype->flags & XCAN_FLAG_TX_MAILBOXES) && + (devtype->flags & XCAN_FLAG_TXFEMP)) + tx_max = min(hw_tx_max, 2U); + else + tx_max = 1; + + rx_max = hw_rx_max; + + /* Create a CAN device instance */ + ndev = alloc_candev(sizeof(struct xcan_priv), tx_max); + if (!ndev) + return -ENOMEM; + + priv = netdev_priv(ndev); + priv->dev = &pdev->dev; + priv->can.bittiming_const = devtype->bittiming_const; + priv->can.do_set_mode = xcan_do_set_mode; + priv->can.do_get_berr_counter = xcan_get_berr_counter; + priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | + CAN_CTRLMODE_BERR_REPORTING; + + if (devtype->cantype == XAXI_CANFD) + priv->can.data_bittiming_const = + &xcan_data_bittiming_const_canfd; + + if (devtype->cantype == XAXI_CANFD_2_0) + priv->can.data_bittiming_const = + &xcan_data_bittiming_const_canfd2; + + if (devtype->cantype == XAXI_CANFD || + devtype->cantype == XAXI_CANFD_2_0) + priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD; + + priv->reg_base = addr; + priv->tx_max = tx_max; + priv->devtype = *devtype; + spin_lock_init(&priv->tx_lock); + + /* Get IRQ for the device */ + ret = platform_get_irq(pdev, 0); + if (ret < 0) + goto err_free; + + ndev->irq = ret; + + ndev->flags |= IFF_ECHO; /* We support local echo */ + + platform_set_drvdata(pdev, ndev); + SET_NETDEV_DEV(ndev, &pdev->dev); + ndev->netdev_ops = &xcan_netdev_ops; + + /* Getting the CAN can_clk info */ + priv->can_clk = devm_clk_get(&pdev->dev, "can_clk"); + if (IS_ERR(priv->can_clk)) { + if (PTR_ERR(priv->can_clk) != -EPROBE_DEFER) + dev_err(&pdev->dev, "Device clock not found.\n"); + ret = PTR_ERR(priv->can_clk); + goto err_free; + } + + priv->bus_clk = devm_clk_get(&pdev->dev, devtype->bus_clk_name); + if (IS_ERR(priv->bus_clk)) { + if (PTR_ERR(priv->bus_clk) != -EPROBE_DEFER) + dev_err(&pdev->dev, "bus clock not found\n"); + ret = PTR_ERR(priv->bus_clk); + goto err_free; + } + + priv->write_reg = xcan_write_reg_le; + priv->read_reg = xcan_read_reg_le; + + pm_runtime_enable(&pdev->dev); + ret = pm_runtime_get_sync(&pdev->dev); + if (ret < 0) { + netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n", + __func__, ret); + goto err_disableclks; + } + + if (priv->read_reg(priv, XCAN_SR_OFFSET) != XCAN_SR_CONFIG_MASK) { + priv->write_reg = xcan_write_reg_be; + priv->read_reg = xcan_read_reg_be; + } + + priv->can.clock.freq = clk_get_rate(priv->can_clk); + + netif_napi_add(ndev, &priv->napi, xcan_rx_poll, rx_max); + + ret = register_candev(ndev); + if (ret) { + dev_err(&pdev->dev, "fail to register failed (err=%d)\n", ret); + goto err_disableclks; + } + + devm_can_led_init(ndev); + + pm_runtime_put(&pdev->dev); + + if (priv->devtype.flags & XCAN_FLAG_CANFD_2) { + priv->write_reg(priv, XCAN_AFR_2_ID_OFFSET, 0x00000000); + priv->write_reg(priv, XCAN_AFR_2_MASK_OFFSET, 0x00000000); + } + + netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx buffers: actual %d, using %d\n", + priv->reg_base, ndev->irq, priv->can.clock.freq, + hw_tx_max, priv->tx_max); + + return 0; + +err_disableclks: + pm_runtime_put(priv->dev); + pm_runtime_disable(&pdev->dev); +err_free: + free_candev(ndev); +err: + return ret; +} + +/** + * xcan_remove - Unregister the device after releasing the resources + * @pdev: Handle to the platform device structure + * + * This function frees all the resources allocated to the device. + * Return: 0 always + */ +static int xcan_remove(struct platform_device *pdev) +{ + struct net_device *ndev = platform_get_drvdata(pdev); + struct xcan_priv *priv = netdev_priv(ndev); + + unregister_candev(ndev); + pm_runtime_disable(&pdev->dev); + netif_napi_del(&priv->napi); + free_candev(ndev); + + return 0; +} + +static struct platform_driver xcan_driver = { + .probe = xcan_probe, + .remove = xcan_remove, + .driver = { + .name = DRIVER_NAME, + .pm = &xcan_dev_pm_ops, + .of_match_table = xcan_of_match, + }, +}; + +module_platform_driver(xcan_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Xilinx Inc"); +MODULE_DESCRIPTION("Xilinx CAN interface"); |