diff options
Diffstat (limited to 'drivers/net/can/xilinx_can.c')
| -rw-r--r-- | drivers/net/can/xilinx_can.c | 1208 |
1 files changed, 1208 insertions, 0 deletions
diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c new file mode 100644 index 00000000000..5e8b5609c06 --- /dev/null +++ b/drivers/net/can/xilinx_can.c @@ -0,0 +1,1208 @@ +/* Xilinx CAN device driver + * + * Copyright (C) 2012 - 2014 Xilinx, Inc. + * Copyright (C) 2009 PetaLogix. All rights reserved. + * + * Description: + * This driver is developed for Axi CAN IP and for Zynq CANPS Controller. + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#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/platform_device.h> +#include <linux/skbuff.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/can/dev.h> +#include <linux/can/error.h> +#include <linux/can/led.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 */ + XCAN_TXFIFO_ID_OFFSET = 0x30,/* TX FIFO ID */ + XCAN_TXFIFO_DLC_OFFSET = 0x34, /* TX FIFO DLC */ + XCAN_TXFIFO_DW1_OFFSET = 0x38, /* TX FIFO Data Word 1 */ + XCAN_TXFIFO_DW2_OFFSET = 0x3C, /* TX FIFO Data Word 2 */ + XCAN_RXFIFO_ID_OFFSET = 0x50, /* RX FIFO ID */ + XCAN_RXFIFO_DLC_OFFSET = 0x54, /* RX FIFO DLC */ + XCAN_RXFIFO_DW1_OFFSET = 0x58, /* RX FIFO Data Word 1 */ + XCAN_RXFIFO_DW2_OFFSET = 0x5C, /* RX FIFO Data Word 2 */ +}; + +/* 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_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_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_INTR_ALL (XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK |\ + XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK | \ + XCAN_IXR_RXNEMP_MASK | XCAN_IXR_ERROR_MASK | \ + XCAN_IXR_ARBLST_MASK | XCAN_IXR_RXOK_MASK) + +/* 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_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 XCAN_TIMEOUT (1 * HZ) + +/** + * struct xcan_priv - This definition define CAN driver instance + * @can: CAN private data structure. + * @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 + */ +struct xcan_priv { + struct can_priv can; + 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 net_device *dev; + void __iomem *reg_base; + unsigned long irq_flags; + struct clk *bus_clk; + struct clk *can_clk; +}; + +/* 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, +}; + +/** + * 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); +} + +/** + * 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); + } + + 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; + 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) << XCAN_BTR_TS2_SHIFT; + + /* Setting Synchronous jump width in BTR Register */ + btr1 |= (bt->sjw - 1) << XCAN_BTR_SJW_SHIFT; + + priv->write_reg(priv, XCAN_BRPR_OFFSET, btr0); + priv->write_reg(priv, XCAN_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 err, reg_msr, reg_sr_mask; + unsigned long timeout; + + /* 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 */ + priv->write_reg(priv, XCAN_IER_OFFSET, XCAN_INTR_ALL); + + /* Check whether it is loopback mode or normal mode */ + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { + reg_msr = XCAN_MSR_LBACK_MASK; + reg_sr_mask = XCAN_SR_LBACK_MASK; + } else { + reg_msr = 0x0; + reg_sr_mask = XCAN_SR_NORMAL_MASK; + } + + priv->write_reg(priv, XCAN_MSR_OFFSET, reg_msr); + priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK); + + timeout = jiffies + XCAN_TIMEOUT; + while (!(priv->read_reg(priv, XCAN_SR_OFFSET) & reg_sr_mask)) { + if (time_after(jiffies, timeout)) { + netdev_warn(ndev, + "timed out for correct mode\n"); + return -ETIMEDOUT; + } + } + 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_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. This + * function uses the next available free txbuff and populates their fields to + * start the transmission. + * + * Return: 0 on success and failure value on error + */ +static int xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev) +{ + struct xcan_priv *priv = netdev_priv(ndev); + struct net_device_stats *stats = &ndev->stats; + struct can_frame *cf = (struct can_frame *)skb->data; + u32 id, dlc, data[2] = {0, 0}; + + if (can_dropped_invalid_skb(ndev, skb)) + return NETDEV_TX_OK; + + /* Check if the TX buffer is full */ + if (unlikely(priv->read_reg(priv, XCAN_SR_OFFSET) & + XCAN_SR_TXFLL_MASK)) { + netif_stop_queue(ndev); + netdev_err(ndev, "BUG!, TX FIFO full when queue awake!\n"); + return NETDEV_TX_BUSY; + } + + /* 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 = cf->can_dlc << XCAN_DLCR_DLC_SHIFT; + + if (cf->can_dlc > 0) + data[0] = be32_to_cpup((__be32 *)(cf->data + 0)); + if (cf->can_dlc > 4) + data[1] = be32_to_cpup((__be32 *)(cf->data + 4)); + + can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max); + priv->tx_head++; + + /* Write the Frame to Xilinx CAN TX FIFO */ + priv->write_reg(priv, XCAN_TXFIFO_ID_OFFSET, id); + /* If the CAN frame is RTR frame this write triggers tranmission */ + priv->write_reg(priv, XCAN_TXFIFO_DLC_OFFSET, dlc); + if (!(cf->can_id & CAN_RTR_FLAG)) { + priv->write_reg(priv, XCAN_TXFIFO_DW1_OFFSET, data[0]); + /* If the CAN frame is Standard/Extended frame this + * write triggers tranmission + */ + priv->write_reg(priv, XCAN_TXFIFO_DW2_OFFSET, data[1]); + stats->tx_bytes += cf->can_dlc; + } + + /* Check if the TX buffer is full */ + if ((priv->tx_head - priv->tx_tail) == priv->tx_max) + netif_stop_queue(ndev); + + return NETDEV_TX_OK; +} + +/** + * xcan_rx - Is called from CAN isr to complete the received + * frame processing + * @ndev: Pointer to net_device structure + * + * 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) +{ + 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_RXFIFO_ID_OFFSET); + dlc = priv->read_reg(priv, XCAN_RXFIFO_DLC_OFFSET) >> + 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; + } + + if (!(id_xcan & XCAN_IDR_SRR_MASK)) { + data[0] = priv->read_reg(priv, XCAN_RXFIFO_DW1_OFFSET); + data[1] = priv->read_reg(priv, XCAN_RXFIFO_DW2_OFFSET); + + /* 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; +} + +/** + * 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; + struct sk_buff *skb; + u32 err_status, status, txerr = 0, rxerr = 0; + + skb = alloc_can_err_skb(ndev, &cf); + + err_status = priv->read_reg(priv, XCAN_ESR_OFFSET); + priv->write_reg(priv, XCAN_ESR_OFFSET, err_status); + txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK; + rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) & + XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT); + status = priv->read_reg(priv, XCAN_SR_OFFSET); + + 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); + if (skb) + cf->can_id |= CAN_ERR_BUSOFF; + } else if ((status & XCAN_SR_ESTAT_MASK) == XCAN_SR_ESTAT_MASK) { + priv->can.state = CAN_STATE_ERROR_PASSIVE; + priv->can.can_stats.error_passive++; + if (skb) { + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] = (rxerr > 127) ? + CAN_ERR_CRTL_RX_PASSIVE : + CAN_ERR_CRTL_TX_PASSIVE; + cf->data[6] = txerr; + cf->data[7] = rxerr; + } + } else if (status & XCAN_SR_ERRWRN_MASK) { + priv->can.state = CAN_STATE_ERROR_WARNING; + priv->can.can_stats.error_warning++; + if (skb) { + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] |= (txerr > rxerr) ? + CAN_ERR_CRTL_TX_WARNING : + CAN_ERR_CRTL_RX_WARNING; + cf->data[6] = txerr; + cf->data[7] = rxerr; + } + } + + /* Check for Arbitration lost interrupt */ + if (isr & XCAN_IXR_ARBLST_MASK) { + priv->can.can_stats.arbitration_lost++; + if (skb) { + 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++; + priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK); + if (skb) { + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW; + } + } + + /* Check for error interrupt */ + if (isr & XCAN_IXR_ERROR_MASK) { + if (skb) { + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; + cf->data[2] |= CAN_ERR_PROT_UNSPEC; + } + + /* Check for Ack error interrupt */ + if (err_status & XCAN_ESR_ACKER_MASK) { + stats->tx_errors++; + if (skb) { + 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 (skb) { + 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 (skb) { + 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 (skb) { + 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 (skb) { + cf->can_id |= CAN_ERR_PROT; + cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ | + CAN_ERR_PROT_LOC_CRC_DEL; + } + } + priv->can.can_stats.bus_error++; + } + + if (skb) { + stats->rx_packets++; + stats->rx_bytes += cf->can_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_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 isr, ier; + int work_done = 0; + + isr = priv->read_reg(priv, XCAN_ISR_OFFSET); + while ((isr & XCAN_IXR_RXNEMP_MASK) && (work_done < quota)) { + if (isr & XCAN_IXR_RXOK_MASK) { + priv->write_reg(priv, XCAN_ICR_OFFSET, + XCAN_IXR_RXOK_MASK); + work_done += xcan_rx(ndev); + } else { + priv->write_reg(priv, XCAN_ICR_OFFSET, + XCAN_IXR_RXNEMP_MASK); + break; + } + priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_RXNEMP_MASK); + isr = priv->read_reg(priv, XCAN_ISR_OFFSET); + } + + if (work_done) + can_led_event(ndev, CAN_LED_EVENT_RX); + + if (work_done < quota) { + napi_complete(napi); + ier = priv->read_reg(priv, XCAN_IER_OFFSET); + ier |= (XCAN_IXR_RXOK_MASK | XCAN_IXR_RXNEMP_MASK); + 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; + + while ((priv->tx_head - priv->tx_tail > 0) && + (isr & XCAN_IXR_TXOK_MASK)) { + priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK); + can_get_echo_skb(ndev, priv->tx_tail % + priv->tx_max); + priv->tx_tail++; + stats->tx_packets++; + isr = priv->read_reg(priv, XCAN_ISR_OFFSET); + } + can_led_event(ndev, CAN_LED_EVENT_TX); + netif_wake_queue(ndev); +} + +/** + * xcan_interrupt - CAN Isr + * @irq: irq number + * @dev_id: device id poniter + * + * 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; + + /* 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 */ + if (isr & (XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK | + XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK)) { + priv->write_reg(priv, XCAN_ICR_OFFSET, (XCAN_IXR_ERROR_MASK | + XCAN_IXR_RXOFLW_MASK | XCAN_IXR_BSOFF_MASK | + XCAN_IXR_ARBLST_MASK)); + xcan_err_interrupt(ndev, isr); + } + + /* Check for the type of receive interrupt and Processing it */ + if (isr & (XCAN_IXR_RXNEMP_MASK | XCAN_IXR_RXOK_MASK)) { + ier = priv->read_reg(priv, XCAN_IER_OFFSET); + ier &= ~(XCAN_IXR_RXNEMP_MASK | XCAN_IXR_RXOK_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); + u32 ier; + + /* Disable interrupts and leave the can in configuration mode */ + ier = priv->read_reg(priv, XCAN_IER_OFFSET); + ier &= ~XCAN_INTR_ALL; + priv->write_reg(priv, XCAN_IER_OFFSET, ier); + priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK); + 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 = 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; + } + + ret = clk_prepare_enable(priv->can_clk); + if (ret) { + netdev_err(ndev, "unable to enable device clock\n"); + goto err_irq; + } + + ret = clk_prepare_enable(priv->bus_clk); + if (ret) { + netdev_err(ndev, "unable to enable bus clock\n"); + goto err_can_clk; + } + + /* Set chip into reset mode */ + ret = set_reset_mode(ndev); + if (ret < 0) { + netdev_err(ndev, "mode resetting failed!\n"); + goto err_bus_clk; + } + + /* Common open */ + ret = open_candev(ndev); + if (ret) + goto err_bus_clk; + + 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_bus_clk: + clk_disable_unprepare(priv->bus_clk); +err_can_clk: + clk_disable_unprepare(priv->can_clk); +err_irq: + free_irq(ndev->irq, ndev); +err: + 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); + clk_disable_unprepare(priv->bus_clk); + clk_disable_unprepare(priv->can_clk); + free_irq(ndev->irq, ndev); + close_candev(ndev); + + can_led_event(ndev, CAN_LED_EVENT_STOP); + + 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 = clk_prepare_enable(priv->can_clk); + if (ret) + goto err; + + ret = clk_prepare_enable(priv->bus_clk); + if (ret) + goto err_clk; + + 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); + + clk_disable_unprepare(priv->bus_clk); + clk_disable_unprepare(priv->can_clk); + + return 0; + +err_clk: + clk_disable_unprepare(priv->can_clk); +err: + return ret; +} + + +static const struct net_device_ops xcan_netdev_ops = { + .ndo_open = xcan_open, + .ndo_stop = xcan_close, + .ndo_start_xmit = xcan_start_xmit, +}; + +/** + * xcan_suspend - Suspend method for the driver + * @dev: Address of the platform_device structure + * + * Put the driver into low power mode. + * Return: 0 always + */ +static int __maybe_unused xcan_suspend(struct device *dev) +{ + struct platform_device *pdev = dev_get_drvdata(dev); + struct net_device *ndev = platform_get_drvdata(pdev); + struct xcan_priv *priv = netdev_priv(ndev); + + if (netif_running(ndev)) { + netif_stop_queue(ndev); + netif_device_detach(ndev); + } + + priv->write_reg(priv, XCAN_MSR_OFFSET, XCAN_MSR_SLEEP_MASK); + priv->can.state = CAN_STATE_SLEEPING; + + clk_disable(priv->bus_clk); + clk_disable(priv->can_clk); + + return 0; +} + +/** + * xcan_resume - Resume from suspend + * @dev: Address of the platformdevice structure + * + * Resume operation after suspend. + * Return: 0 on success and failure value on error + */ +static int __maybe_unused xcan_resume(struct device *dev) +{ + struct platform_device *pdev = dev_get_drvdata(dev); + struct net_device *ndev = platform_get_drvdata(pdev); + struct xcan_priv *priv = netdev_priv(ndev); + int ret; + + ret = clk_enable(priv->bus_clk); + if (ret) { + dev_err(dev, "Cannot enable clock.\n"); + return ret; + } + ret = clk_enable(priv->can_clk); + if (ret) { + dev_err(dev, "Cannot enable clock.\n"); + clk_disable_unprepare(priv->bus_clk); + return ret; + } + + priv->write_reg(priv, XCAN_MSR_OFFSET, 0); + priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK); + priv->can.state = CAN_STATE_ERROR_ACTIVE; + + if (netif_running(ndev)) { + netif_device_attach(ndev); + netif_start_queue(ndev); + } + + return 0; +} + +static SIMPLE_DEV_PM_OPS(xcan_dev_pm_ops, xcan_suspend, xcan_resume); + +/** + * 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 resource *res; /* IO mem resources */ + struct net_device *ndev; + struct xcan_priv *priv; + void __iomem *addr; + int ret, rx_max, tx_max; + + /* Get the virtual base address for the device */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + addr = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(addr)) { + ret = PTR_ERR(addr); + goto err; + } + + ret = of_property_read_u32(pdev->dev.of_node, "tx-fifo-depth", &tx_max); + if (ret < 0) + goto err; + + ret = of_property_read_u32(pdev->dev.of_node, "rx-fifo-depth", &rx_max); + if (ret < 0) + goto err; + + /* Create a CAN device instance */ + ndev = alloc_candev(sizeof(struct xcan_priv), tx_max); + if (!ndev) + return -ENOMEM; + + priv = netdev_priv(ndev); + priv->dev = ndev; + priv->can.bittiming_const = &xcan_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; + priv->reg_base = addr; + priv->tx_max = tx_max; + + /* Get IRQ for the device */ + ndev->irq = platform_get_irq(pdev, 0); + 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)) { + dev_err(&pdev->dev, "Device clock not found.\n"); + ret = PTR_ERR(priv->can_clk); + goto err_free; + } + /* Check for type of CAN device */ + if (of_device_is_compatible(pdev->dev.of_node, + "xlnx,zynq-can-1.0")) { + priv->bus_clk = devm_clk_get(&pdev->dev, "pclk"); + if (IS_ERR(priv->bus_clk)) { + dev_err(&pdev->dev, "bus clock not found\n"); + ret = PTR_ERR(priv->bus_clk); + goto err_free; + } + } else { + priv->bus_clk = devm_clk_get(&pdev->dev, "s_axi_aclk"); + if (IS_ERR(priv->bus_clk)) { + dev_err(&pdev->dev, "bus clock not found\n"); + ret = PTR_ERR(priv->bus_clk); + goto err_free; + } + } + + ret = clk_prepare_enable(priv->can_clk); + if (ret) { + dev_err(&pdev->dev, "unable to enable device clock\n"); + goto err_free; + } + + ret = clk_prepare_enable(priv->bus_clk); + if (ret) { + dev_err(&pdev->dev, "unable to enable bus clock\n"); + goto err_unprepare_disable_dev; + } + + priv->write_reg = xcan_write_reg_le; + priv->read_reg = xcan_read_reg_le; + + 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_unprepare_disable_busclk; + } + + devm_can_led_init(ndev); + clk_disable_unprepare(priv->bus_clk); + clk_disable_unprepare(priv->can_clk); + netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx fifo depth:%d\n", + priv->reg_base, ndev->irq, priv->can.clock.freq, + priv->tx_max); + + return 0; + +err_unprepare_disable_busclk: + clk_disable_unprepare(priv->bus_clk); +err_unprepare_disable_dev: + clk_disable_unprepare(priv->can_clk); +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); + + if (set_reset_mode(ndev) < 0) + netdev_err(ndev, "mode resetting failed!\n"); + + unregister_candev(ndev); + netif_napi_del(&priv->napi); + free_candev(ndev); + + return 0; +} + +/* Match table for OF platform binding */ +static struct of_device_id xcan_of_match[] = { + { .compatible = "xlnx,zynq-can-1.0", }, + { .compatible = "xlnx,axi-can-1.00.a", }, + { /* end of list */ }, +}; +MODULE_DEVICE_TABLE(of, xcan_of_match); + +static struct platform_driver xcan_driver = { + .probe = xcan_probe, + .remove = xcan_remove, + .driver = { + .owner = THIS_MODULE, + .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"); |