> Bosch C_CAN controller is a full-CAN implementation which is compliant
> to CAN protocol version 2.0 part A and B. Bosch C_CAN user manual can be
> obtained from:
>
http://www.semiconductors.bosch.de/pdf/Users_Manual_C_CAN.pdf
>
> This patch adds the support for this controller.
> The following are the design choices made while writing the controller driver:
> 1. Interface Register set IF1 has be used only in the current design.
> 2. Out of the 32 Message objects available, 16 are kept aside for RX purposes
> and the rest for TX purposes.
> 3. NAPI implementation is such that both the TX and RX paths function in
> polling mode.
>
> Changes since V1:
> 1. Implemented C_CAN as a platform driver with means of providing the
> platform details and register offsets which may vary for different SoCs
> through platform data struct.
> 2. Implemented NAPI.
> 3. Removed memcpy calls globally.
> 4. Implemented CAN_CTRLMODE_*
> 5. Implemented and used priv->can.do_get_berr_counter.
> 6. Implemented c_can registers as a struct instead of enum.
> 7. Improved the TX path by implementing routines to get next Tx and echo msg
> objects.
>
> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@st.com>
> ---
> drivers/net/can/Kconfig | 7 +
> drivers/net/can/Makefile | 1 +
> drivers/net/can/c_can.c | 1217 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 1225 insertions(+), 0 deletions(-)
> create mode 100644 drivers/net/can/c_can.c
>
> diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
> index 9d9e453..25d9d2e 100644
> --- a/drivers/net/can/Kconfig
> +++ b/drivers/net/can/Kconfig
> @@ -41,6 +41,13 @@ config CAN_AT91
> ---help---
> This is a driver for the SoC CAN controller in Atmel's AT91SAM9263.
>
> +config CAN_C_CAN
> + tristate "Bosch C_CAN controller"
> + depends on CAN_DEV
> + ---help---
> + If you say yes to this option, support will be included for the
> + Bosch C_CAN controller.
> +
> config CAN_TI_HECC
> depends on CAN_DEV && ARCH_OMAP3
> tristate "TI High End CAN Controller"
> diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
> index 0057537..b6cbe74 100644
> --- a/drivers/net/can/Makefile
> +++ b/drivers/net/can/Makefile
> @@ -12,6 +12,7 @@ obj-y += usb/
> obj-$(CONFIG_CAN_SJA1000) += sja1000/
> obj-$(CONFIG_CAN_MSCAN) += mscan/
> obj-$(CONFIG_CAN_AT91) += at91_can.o
> +obj-$(CONFIG_CAN_C_CAN) += c_can.o
> obj-$(CONFIG_CAN_TI_HECC) += ti_hecc.o
> obj-$(CONFIG_CAN_MCP251X) += mcp251x.o
> obj-$(CONFIG_CAN_BFIN) += bfin_can.o
> diff --git a/drivers/net/can/c_can.c b/drivers/net/can/c_can.c
> new file mode 100644
> index 0000000..c281c17
> --- /dev/null
> +++ b/drivers/net/can/c_can.c
> @@ -0,0 +1,1217 @@
> +/*
> + * CAN bus driver for Bosch C_CAN controller
> + *
> + * Copyright (C) 2010 ST Microelectronics
> + * Bhupesh Sharma <bhupesh.sharma@st.com>
> + *
> + * Borrowed heavily from the C_CAN driver originally written by:
> + * Copyright (C) 2007
> + * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <s.hauer@pengutronix.de>
> + * - Simon Kallweit, intefo AG <simon.kallweit@intefo.ch>
> + *
> + * Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A and B.
> + * Bosch C_CAN user manual can be obtained from:
> + *
http://www.semiconductors.bosch.de/pdf/Users_Manual_C_CAN.pdf
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/version.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/netdevice.h>
> +#include <linux/if_arp.h>
> +#include <linux/if_ether.h>
> +#include <linux/list.h>
> +#include <linux/delay.h>
> +#include <linux/workqueue.h>
> +#include <linux/io.h>
> +#include <linux/platform_device.h>
> +#include <linux/clk.h>
> +
> +#include <linux/can.h>
> +#include <linux/can/dev.h>
> +#include <linux/can/error.h>
> +
> +#define DRV_NAME "c_can"
> +
> +/* control register */
> +#define CONTROL_TEST (1 << 7)
> +#define CONTROL_CCE (1 << 6)
> +#define CONTROL_DISABLE_AR (1 << 5)
> +#define CONTROL_ENABLE_AR (0 << 5)
> +#define CONTROL_EIE (1 << 3)
> +#define CONTROL_SIE (1 << 2)
> +#define CONTROL_IE (1 << 1)
> +#define CONTROL_INIT (1 << 0)
> +
> +/* test register */
> +#define TEST_RX (1 << 7)
> +#define TEST_TX1 (1 << 6)
> +#define TEST_TX2 (1 << 5)
> +#define TEST_LBACK (1 << 4)
> +#define TEST_SILENT (1 << 3)
> +#define TEST_BASIC (1 << 2)
> +
> +/* status register */
> +#define STATUS_BOFF (1 << 7)
> +#define STATUS_EWARN (1 << 6)
> +#define STATUS_EPASS (1 << 5)
> +#define STATUS_RXOK (1 << 4)
> +#define STATUS_TXOK (1 << 3)
> +#define STATUS_LEC_MASK 0x07
> +#define LEC_STUFF_ERROR 1
> +#define LEC_FORM_ERROR 2
> +#define LEC_ACK_ERROR 3
> +#define LEC_BIT1_ERROR 4
> +#define LEC_BIT0_ERROR 5
> +#define LEC_CRC_ERROR 6
> +
> +/* error counter register */
> +#define ERR_COUNTER_TEC_MASK 0xff
> +#define ERR_COUNTER_TEC_SHIFT 0x0
> +#define ERR_COUNTER_REC_SHIFT 8
> +#define ERR_COUNTER_REC_MASK (0x7f << ERR_COUNTER_REC_SHIFT)
> +#define ERR_COUNTER_RP_SHIFT 15
> +#define ERR_COUNTER_RP_MASK (0x1 << ERR_COUNTER_RP_SHIFT)
> +
> +/* bit-timing register */
> +#define BTR_BRP_MASK 0x3f
> +#define BTR_BRP_SHIFT 0
> +#define BTR_SJW_SHIFT 6
> +#define BTR_SJW_MASK (0x3 << BTR_SJW_SHIFT)
> +#define BTR_TSEG1_SHIFT 8
> +#define BTR_TSEG1_MASK (0xf << BTR_TSEG1_SHIFT)
> +#define BTR_TSEG2_SHIFT 12
> +#define BTR_TSEG2_MASK (0x7 << BTR_TSEG2_SHIFT)
> +
> +/* brp extension register */
> +#define BRP_EXT_BRPE_MASK 0x0f
> +#define BRP_EXT_BRPE_SHIFT 0
> +
> +/* IFx command request */
> +#define IF_COMR_BUSY (1 << 15)
> +
> +/* IFx command mask */
> +#define IF_COMM_WR (1 << 7)
> +#define IF_COMM_MASK (1 << 6)
> +#define IF_COMM_ARB (1 << 5)
> +#define IF_COMM_CONTROL (1 << 4)
> +#define IF_COMM_CLR_INT_PND (1 << 3)
> +#define IF_COMM_TXRQST (1 << 2)
> +#define IF_COMM_DATAA (1 << 1)
> +#define IF_COMM_DATAB (1 << 0)
> +#define IF_COMM_ALL (IF_COMM_MASK | IF_COMM_ARB | \
> + IF_COMM_CONTROL | IF_COMM_TXRQST | \
> + IF_COMM_DATAA | IF_COMM_DATAB)
> +
> +/* IFx arbitration */
> +#define IF_ARB_MSGVAL (1 << 15)
> +#define IF_ARB_MSGXTD (1 << 14)
> +#define IF_ARB_TRANSMIT (1 << 13)
> +
> +/* IFx message control */
> +#define IF_MCONT_NEWDAT (1 << 15)
> +#define IF_MCONT_MSGLST (1 << 14)
> +#define IF_MCONT_INTPND (1 << 13)
> +#define IF_MCONT_UMASK (1 << 12)
> +#define IF_MCONT_TXIE (1 << 11)
> +#define IF_MCONT_RXIE (1 << 10)
> +#define IF_MCONT_RMTEN (1 << 9)
> +#define IF_MCONT_TXRQST (1 << 8)
> +#define IF_MCONT_EOB (1 << 7)
> +
> +/*
> + * IFx register masks:
> + * allow easy operation on 16-bit registers when the
> + * argument is 32-bit instead
> + */
> +#define IFX_WRITE_LOW_16BIT(x) (x & 0xFFFF)
> +#define IFX_WRITE_HIGH_16BIT(x) ((x & 0xFFFF0000) >> 16)
> +
> +/* message object split */
> +#define C_CAN_NO_OF_OBJECTS 31
> +#define C_CAN_MSG_OBJ_RX_NUM 16
> +#define C_CAN_MSG_OBJ_TX_NUM 16
> +
> +#define C_CAN_MSG_OBJ_RX_FIRST 0
> +#define C_CAN_MSG_OBJ_RX_LAST (C_CAN_MSG_OBJ_RX_FIRST + \
> + C_CAN_MSG_OBJ_RX_NUM - 1)
> +
> +#define C_CAN_MSG_OBJ_TX_FIRST (C_CAN_MSG_OBJ_RX_LAST + 1)
> +#define C_CAN_MSG_OBJ_TX_LAST (C_CAN_MSG_OBJ_TX_FIRST + \
> + C_CAN_MSG_OBJ_TX_NUM - 1)
> +#define C_CAN_NEXT_MSG_OBJ_MASK (C_CAN_MSG_OBJ_TX_NUM - 1)
> +#define RECEIVE_OBJECT_BITS 0x0000ffff
> +
> +/* status interrupt */
> +#define STATUS_INTERRUPT 0x8000
> +
> +/* napi related */
> +#define C_CAN_NAPI_WEIGHT C_CAN_MSG_OBJ_RX_NUM
> +
> +/* c_can IF registers */
> +struct c_can_if_regs {
> + u16 com_reg;
> + u16 com_mask;
> + u16 mask1;
> + u16 mask2;
> + u16 arb1;
> + u16 arb2;
> + u16 msg_cntrl;
> + u16 data_a1;
> + u16 data_a2;
> + u16 data_b1;
> + u16 data_b2;
> + u16 _reserved[13];
> +};
> +
> +/* c_can hardware registers */
> +struct c_can_regs {
> + u16 control;
> + u16 status;
> + u16 error_counter;
> + u16 btr;
> + u16 ir;
> + u16 test;
> + u16 brp_ext;
> + u16 _reserved1;
> + struct c_can_if_regs ifreg[2]; /* [0] = IF1 and [1] = IF2 */
> + u16 _reserved2[8];
> + u16 txrqst1;
> + u16 txrqst2;
> + u16 _reserved3[6];
> + u16 newdat1;
> + u16 newdat2;
> + u16 _reserved4[6];
> + u16 intpnd1;
> + u16 intpnd2;
> + u16 _reserved5[6];
> + u16 msgval1;
> + u16 msgval2;
> + u16 _reserved6[6];
> +};
