path: root/drivers/net/can/mcp251x.c

/*
 * CAN bus driver for Microchip 251x CAN Controller with SPI Interface
 *
 * MCP2510 support and bug fixes by Christian Pellegrin
 * <chripell@evolware.org>
 *
 * Copyright 2009 Christian Pellegrin EVOL S.r.l.
 *
 * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
 * Written under contract by:
 *   Chris Elston, Katalix Systems, Ltd.
 *
 * Based on Microchip MCP251x CAN controller driver written by
 * David Vrabel, Copyright 2006 Arcom Control Systems Ltd.
 *
 * Based on CAN bus driver for the CCAN controller written by
 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
 * - Simon Kallweit, intefo AG
 * Copyright 2007
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the version 2 of the GNU General Public License
 * as published by the Free Software Foundation
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 *
 *
 * Your platform definition file should specify something like:
 *
 * static struct mcp251x_platform_data mcp251x_info = {
 *         .oscillator_frequency = 8000000,
 * };
 *
 * static struct spi_board_info spi_board_info[] = {
 *         {
 *                 .modalias = "mcp2510",
 *			// or "mcp2515" depending on your controller
 *                 .platform_data = &mcp251x_info,
 *                 .irq = IRQ_EINT13,
 *                 .max_speed_hz = 2*1000*1000,
 *                 .chip_select = 2,
 *         },
 * };
 *
 * Please see mcp251x.h for a description of the fields in
 * struct mcp251x_platform_data.
 *
 */

#include <linux/can/core.h>
#include <linux/can/dev.h>
#include <linux/can/led.h>
#include <linux/can/platform/mcp251x.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/freezer.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/slab.h>
#include <linux/spi/spi.h>
#include <linux/uaccess.h>
#include <linux/regulator/consumer.h>

/* SPI interface instruction set */
#define INSTRUCTION_WRITE	0x02
#define INSTRUCTION_READ	0x03
#define INSTRUCTION_BIT_MODIFY	0x05
#define INSTRUCTION_LOAD_TXB(n)	(0x40 + 2 * (n))
#define INSTRUCTION_READ_RXB(n)	(((n) == 0) ? 0x90 : 0x94)
#define INSTRUCTION_RESET	0xC0
#define RTS_TXB0		0x01
#define RTS_TXB1		0x02
#define RTS_TXB2		0x04
#define INSTRUCTION_RTS(n)	(0x80 | ((n) & 0x07))


/* MPC251x registers */
#define CANSTAT	      0x0e
#define CANCTRL	      0x0f
#  define CANCTRL_REQOP_MASK	    0xe0
#  define CANCTRL_REQOP_CONF	    0x80
#  define CANCTRL_REQOP_LISTEN_ONLY 0x60
#  define CANCTRL_REQOP_LOOPBACK    0x40
#  define CANCTRL_REQOP_SLEEP	    0x20
#  define CANCTRL_REQOP_NORMAL	    0x00
#  define CANCTRL_OSM		    0x08
#  define CANCTRL_ABAT		    0x10
#define TEC	      0x1c
#define REC	      0x1d
#define CNF1	      0x2a
#  define CNF1_SJW_SHIFT   6
#define CNF2	      0x29
#  define CNF2_BTLMODE	   0x80
#  define CNF2_SAM         0x40
#  define CNF2_PS1_SHIFT   3
#define CNF3	      0x28
#  define CNF3_SOF	   0x08
#  define CNF3_WAKFIL	   0x04
#  define CNF3_PHSEG2_MASK 0x07
#define CANINTE	      0x2b
#  define CANINTE_MERRE 0x80
#  define CANINTE_WAKIE 0x40
#  define CANINTE_ERRIE 0x20
#  define CANINTE_TX2IE 0x10
#  define CANINTE_TX1IE 0x08
#  define CANINTE_TX0IE 0x04
#  define CANINTE_RX1IE 0x02
#  define CANINTE_RX0IE 0x01
#define CANINTF	      0x2c
#  define CANINTF_MERRF 0x80
#  define CANINTF_WAKIF 0x40
#  define CANINTF_ERRIF 0x20
#  define CANINTF_TX2IF 0x10
#  define CANINTF_TX1IF 0x08
#  define CANINTF_TX0IF 0x04
#  define CANINTF_RX1IF 0x02
#  define CANINTF_RX0IF 0x01
#  define CANINTF_RX (CANINTF_RX0IF | CANINTF_RX1IF)
#  define CANINTF_TX (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF)
#  define CANINTF_ERR (CANINTF_ERRIF)
#define EFLG	      0x2d
#  define EFLG_EWARN	0x01
#  define EFLG_RXWAR	0x02
#  define EFLG_TXWAR	0x04
#  define EFLG_RXEP	0x08
#  define EFLG_TXEP	0x10
#  define EFLG_TXBO	0x20
#  define EFLG_RX0OVR	0x40
#  define EFLG_RX1OVR	0x80
#define TXBCTRL(n)  (((n) * 0x10) + 0x30 + TXBCTRL_OFF)
#  define TXBCTRL_ABTF	0x40
#  define TXBCTRL_MLOA	0x20
#  define TXBCTRL_TXERR 0x10
#  define TXBCTRL_TXREQ 0x08
#define TXBSIDH(n)  (((n) * 0x10) + 0x30 + TXBSIDH_OFF)
#  define SIDH_SHIFT    3
#define TXBSIDL(n)  (((n) * 0x10) + 0x30 + TXBSIDL_OFF)
#  define SIDL_SID_MASK    7
#  define SIDL_SID_SHIFT   5
#  define SIDL_EXIDE_SHIFT 3
#  define SIDL_EID_SHIFT   16
#  define SIDL_EID_MASK    3
#define TXBEID8(n)  (((n) * 0x10) + 0x30 + TXBEID8_OFF)
#define TXBEID0(n)  (((n) * 0x10) + 0x30 + TXBEID0_OFF)
#define TXBDLC(n)   (((n) * 0x10) + 0x30 + TXBDLC_OFF)
#  define DLC_RTR_SHIFT    6
#define TXBCTRL_OFF 0
#define TXBSIDH_OFF 1
#define TXBSIDL_OFF 2
#define TXBEID8_OFF 3
#define TXBEID0_OFF 4
#define TXBDLC_OFF  5
#define TXBDAT_OFF  6
#define RXBCTRL(n)  (((n) * 0x10) + 0x60 + RXBCTRL_OFF)
#  define RXBCTRL_BUKT	0x04
#  define RXBCTRL_RXM0	0x20
#  define RXBCTRL_RXM1	0x40
#define RXBSIDH(n)  (((n) * 0x10) + 0x60 + RXBSIDH_OFF)
#  define RXBSIDH_SHIFT 3
#define RXBSIDL(n)  (((n) * 0x10) + 0x60 + RXBSIDL_OFF)
#  define RXBSIDL_IDE   0x08
#  define RXBSIDL_SRR   0x10
#  define RXBSIDL_EID   3
#  define RXBSIDL_SHIFT 5
#define RXBEID8(n)  (((n) * 0x10) + 0x60 + RXBEID8_OFF)
#define RXBEID0(n)  (((n) * 0x10) + 0x60 + RXBEID0_OFF)
#define RXBDLC(n)   (((n) * 0x10) + 0x60 + RXBDLC_OFF)
#  define RXBDLC_LEN_MASK  0x0f
#  define RXBDLC_RTR       0x40
#define RXBCTRL_OFF 0
#define RXBSIDH_OFF 1
#define RXBSIDL_OFF 2
#define RXBEID8_OFF 3
#define RXBEID0_OFF 4
#define RXBDLC_OFF  5
#define RXBDAT_OFF  6
#define RXFSIDH(n) ((n) * 4)
#define RXFSIDL(n) ((n) * 4 + 1)
#define RXFEID8(n) ((n) * 4 + 2)
#define RXFEID0(n) ((n) * 4 + 3)
#define RXMSIDH(n) ((n) * 4 + 0x20)
#define RXMSIDL(n) ((n) * 4 + 0x21)
#define RXMEID8(n) ((n) * 4 + 0x22)
#define RXMEID0(n) ((n) * 4 + 0x23)

#define GET_BYTE(val, byte)			\
	(((val) >> ((byte) * 8)) & 0xff)
#define SET_BYTE(val, byte)			\
	(((val) & 0xff) << ((byte) * 8))

/*
 * Buffer size required for the largest SPI transfer (i.e., reading a
 * frame)
 */
#define CAN_FRAME_MAX_DATA_LEN	8
#define SPI_TRANSFER_BUF_LEN	(6 + CAN_FRAME_MAX_DATA_LEN)
#define CAN_FRAME_MAX_BITS	128

#define TX_ECHO_SKB_MAX	1

#define DEVICE_NAME "mcp251x"

static int mcp251x_enable_dma; /* Enable SPI DMA. Default: 0 (Off) */
module_param(mcp251x_enable_dma, int, S_IRUGO);
MODULE_PARM_DESC(mcp251x_enable_dma, "Enable SPI DMA. Default: 0 (Off)");

stat