/* 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