diff options
Diffstat (limited to 'drivers/net/can/mcp251x.c')
| -rw-r--r-- | drivers/net/can/mcp251x.c | 1159 |
1 files changed, 0 insertions, 1159 deletions
diff --git a/drivers/net/can/mcp251x.c b/drivers/net/can/mcp251x.c deleted file mode 100644 index 9c5a1537939..00000000000 --- a/drivers/net/can/mcp251x.c +++ /dev/null @@ -1,1159 +0,0 @@ -/* - * 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, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - * - * - * - * Your platform definition file should specify something like: - * - * static struct mcp251x_platform_data mcp251x_info = { - * .oscillator_frequency = 8000000, - * .board_specific_setup = &mcp251x_setup, - * .model = CAN_MCP251X_MCP2510, - * .power_enable = mcp251x_power_enable, - * .transceiver_enable = NULL, - * }; - * - * static struct spi_board_info spi_board_info[] = { - * { - * .modalias = "mcp251x", - * .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.h> -#include <linux/can/core.h> -#include <linux/can/dev.h> -#include <linux/can/platform/mcp251x.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/platform_device.h> -#include <linux/spi/spi.h> -#include <linux/uaccess.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 - -/* 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 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_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 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)"); - -static struct can_bittiming_const mcp251x_bittiming_const = { - .name = DEVICE_NAME, - .tseg1_min = 3, - .tseg1_max = 16, - .tseg2_min = 2, - .tseg2_max = 8, - .sjw_max = 4, - .brp_min = 1, - .brp_max = 64, - .brp_inc = 1, -}; - -struct mcp251x_priv { - struct can_priv can; - struct net_device *net; - struct spi_device *spi; - - struct mutex spi_lock; /* SPI buffer lock */ - u8 *spi_tx_buf; - u8 *spi_rx_buf; - dma_addr_t spi_tx_dma; - dma_addr_t spi_rx_dma; - - struct sk_buff *tx_skb; - int tx_len; - struct workqueue_struct *wq; - struct work_struct tx_work; - struct work_struct irq_work; - struct completion awake; - int wake; - int force_quit; - int after_suspend; -#define AFTER_SUSPEND_UP 1 -#define AFTER_SUSPEND_DOWN 2 -#define AFTER_SUSPEND_POWER 4 -#define AFTER_SUSPEND_RESTART 8 - int restart_tx; -}; - -static void mcp251x_clean(struct net_device *net) -{ - struct mcp251x_priv *priv = netdev_priv(net); - - net->stats.tx_errors++; - if (priv->tx_skb) - dev_kfree_skb(priv->tx_skb); - if (priv->tx_len) - can_free_echo_skb(priv->net, 0); - priv->tx_skb = NULL; - priv->tx_len = 0; -} - -/* - * Note about handling of error return of mcp251x_spi_trans: accessing - * registers via SPI is not really different conceptually than using - * normal I/O assembler instructions, although it's much more - * complicated from a practical POV. So it's not advisable to always - * check the return value of this function. Imagine that every - * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0) - * error();", it would be a great mess (well there are some situation - * when exception handling C++ like could be useful after all). So we - * just check that transfers are OK at the beginning of our - * conversation with the chip and to avoid doing really nasty things - * (like injecting bogus packets in the network stack). - */ -static int mcp251x_spi_trans(struct spi_device *spi, int len) -{ - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - struct spi_transfer t = { - .tx_buf = priv->spi_tx_buf, - .rx_buf = priv->spi_rx_buf, - .len = len, - .cs_change = 0, - }; - struct spi_message m; - int ret; - - spi_message_init(&m); - - if (mcp251x_enable_dma) { - t.tx_dma = priv->spi_tx_dma; - t.rx_dma = priv->spi_rx_dma; - m.is_dma_mapped = 1; - } - - spi_message_add_tail(&t, &m); - - ret = spi_sync(spi, &m); - if (ret) - dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret); - return ret; -} - -static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg) -{ - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - u8 val = 0; - - mutex_lock(&priv->spi_lock); - - priv->spi_tx_buf[0] = INSTRUCTION_READ; - priv->spi_tx_buf[1] = reg; - - mcp251x_spi_trans(spi, 3); - val = priv->spi_rx_buf[2]; - - mutex_unlock(&priv->spi_lock); - - return val; -} - -static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val) -{ - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - - mutex_lock(&priv->spi_lock); - - priv->spi_tx_buf[0] = INSTRUCTION_WRITE; - priv->spi_tx_buf[1] = reg; - priv->spi_tx_buf[2] = val; - - mcp251x_spi_trans(spi, 3); - - mutex_unlock(&priv->spi_lock); -} - -static void mcp251x_write_bits(struct spi_device *spi, u8 reg, - u8 mask, uint8_t val) -{ - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - - mutex_lock(&priv->spi_lock); - - priv->spi_tx_buf[0] = INSTRUCTION_BIT_MODIFY; - priv->spi_tx_buf[1] = reg; - priv->spi_tx_buf[2] = mask; - priv->spi_tx_buf[3] = val; - - mcp251x_spi_trans(spi, 4); - - mutex_unlock(&priv->spi_lock); -} - -static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf, - int len, int tx_buf_idx) -{ - struct mcp251x_platform_data *pdata = spi->dev.platform_data; - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - - if (pdata->model == CAN_MCP251X_MCP2510) { - int i; - - for (i = 1; i < TXBDAT_OFF + len; i++) - mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i, - buf[i]); - } else { - mutex_lock(&priv->spi_lock); - memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len); - mcp251x_spi_trans(spi, TXBDAT_OFF + len); - mutex_unlock(&priv->spi_lock); - } -} - -static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame, - int tx_buf_idx) -{ - u32 sid, eid, exide, rtr; - u8 buf[SPI_TRANSFER_BUF_LEN]; - - exide = (frame->can_id & CAN_EFF_FLAG) ? 1 : 0; /* Extended ID Enable */ - if (exide) - sid = (frame->can_id & CAN_EFF_MASK) >> 18; - else - sid = frame->can_id & CAN_SFF_MASK; /* Standard ID */ - eid = frame->can_id & CAN_EFF_MASK; /* Extended ID */ - rtr = (frame->can_id & CAN_RTR_FLAG) ? 1 : 0; /* Remote transmission */ - - buf[TXBCTRL_OFF] = INSTRUCTION_LOAD_TXB(tx_buf_idx); - buf[TXBSIDH_OFF] = sid >> SIDH_SHIFT; - buf[TXBSIDL_OFF] = ((sid & SIDL_SID_MASK) << SIDL_SID_SHIFT) | - (exide << SIDL_EXIDE_SHIFT) | - ((eid >> SIDL_EID_SHIFT) & SIDL_EID_MASK); - buf[TXBEID8_OFF] = GET_BYTE(eid, 1); - buf[TXBEID0_OFF] = GET_BYTE(eid, 0); - buf[TXBDLC_OFF] = (rtr << DLC_RTR_SHIFT) | frame->can_dlc; - memcpy(buf + TXBDAT_OFF, frame->data, frame->can_dlc); - mcp251x_hw_tx_frame(spi, buf, frame->can_dlc, tx_buf_idx); - mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx), TXBCTRL_TXREQ); -} - -static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf, - int buf_idx) -{ - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - struct mcp251x_platform_data *pdata = spi->dev.platform_data; - - if (pdata->model == CAN_MCP251X_MCP2510) { - int i, len; - - for (i = 1; i < RXBDAT_OFF; i++) - buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i); - - len = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK); - for (; i < (RXBDAT_OFF + len); i++) - buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i); - } else { - mutex_lock(&priv->spi_lock); - - priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx); - mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN); - memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN); - - mutex_unlock(&priv->spi_lock); - } -} - -static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx) -{ - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - struct sk_buff *skb; - struct can_frame *frame; - u8 buf[SPI_TRANSFER_BUF_LEN]; - - skb = alloc_can_skb(priv->net, &frame); - if (!skb) { - dev_err(&spi->dev, "cannot allocate RX skb\n"); - priv->net->stats.rx_dropped++; - return; - } - - mcp251x_hw_rx_frame(spi, buf, buf_idx); - if (buf[RXBSIDL_OFF] & RXBSIDL_IDE) { - /* Extended ID format */ - frame->can_id = CAN_EFF_FLAG; - frame->can_id |= - /* Extended ID part */ - SET_BYTE(buf[RXBSIDL_OFF] & RXBSIDL_EID, 2) | - SET_BYTE(buf[RXBEID8_OFF], 1) | - SET_BYTE(buf[RXBEID0_OFF], 0) | - /* Standard ID part */ - (((buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) | - (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT)) << 18); - /* Remote transmission request */ - if (buf[RXBDLC_OFF] & RXBDLC_RTR) - frame->can_id |= CAN_RTR_FLAG; - } else { - /* Standard ID format */ - frame->can_id = - (buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) | - (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT); - } - /* Data length */ - frame->can_dlc = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK); - memcpy(frame->data, buf + RXBDAT_OFF, frame->can_dlc); - - priv->net->stats.rx_packets++; - priv->net->stats.rx_bytes += frame->can_dlc; - netif_rx(skb); -} - -static void mcp251x_hw_sleep(struct spi_device *spi) -{ - mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP); -} - -static void mcp251x_hw_wakeup(struct spi_device *spi) -{ - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - - priv->wake = 1; - - /* Can only wake up by generating a wake-up interrupt. */ - mcp251x_write_bits(spi, CANINTE, CANINTE_WAKIE, CANINTE_WAKIE); - mcp251x_write_bits(spi, CANINTF, CANINTF_WAKIF, CANINTF_WAKIF); - - /* Wait until the device is awake */ - if (!wait_for_completion_timeout(&priv->awake, HZ)) - dev_err(&spi->dev, "MCP251x didn't wake-up\n"); -} - -static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb, - struct net_device *net) -{ - struct mcp251x_priv *priv = netdev_priv(net); - struct spi_device *spi = priv->spi; - - if (priv->tx_skb || priv->tx_len) { - dev_warn(&spi->dev, "hard_xmit called while tx busy\n"); - netif_stop_queue(net); - return NETDEV_TX_BUSY; - } - - if (skb->len != sizeof(struct can_frame)) { - dev_err(&spi->dev, "dropping packet - bad length\n"); - dev_kfree_skb(skb); - net->stats.tx_dropped++; - return NETDEV_TX_OK; - } - - netif_stop_queue(net); - priv->tx_skb = skb; - net->trans_start = jiffies; - queue_work(priv->wq, &priv->tx_work); - - return NETDEV_TX_OK; -} - -static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode) -{ - struct mcp251x_priv *priv = netdev_priv(net); - - switch (mode) { - case CAN_MODE_START: - /* We have to delay work since SPI I/O may sleep */ - priv->can.state = CAN_STATE_ERROR_ACTIVE; - priv->restart_tx = 1; - if (priv->can.restart_ms == 0) - priv->after_suspend = AFTER_SUSPEND_RESTART; - queue_work(priv->wq, &priv->irq_work); - break; - default: - return -EOPNOTSUPP; - } - - return 0; -} - -static void mcp251x_set_normal_mode(struct spi_device *spi) -{ - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - unsigned long timeout; - - /* Enable interrupts */ - mcp251x_write_reg(spi, CANINTE, - CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE | - CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE | - CANINTF_MERRF); - - if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { - /* Put device into loopback mode */ - mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK); - } else { - /* Put device into normal mode */ - mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL); - - /* Wait for the device to enter normal mode */ - timeout = jiffies + HZ; - while (mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) { - schedule(); - if (time_after(jiffies, timeout)) { - dev_err(&spi->dev, "MCP251x didn't" - " enter in normal mode\n"); - return; - } - } - } - priv->can.state = CAN_STATE_ERROR_ACTIVE; -} - -static int mcp251x_do_set_bittiming(struct net_device *net) -{ - struct mcp251x_priv *priv = netdev_priv(net); - struct can_bittiming *bt = &priv->can.bittiming; - struct spi_device *spi = priv->spi; - - mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) | - (bt->brp - 1)); - mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE | - (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ? - CNF2_SAM : 0) | - ((bt->phase_seg1 - 1) << CNF2_PS1_SHIFT) | - (bt->prop_seg - 1)); - mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK, - (bt->phase_seg2 - 1)); - dev_info(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x\n", - mcp251x_read_reg(spi, CNF1), - mcp251x_read_reg(spi, CNF2), - mcp251x_read_reg(spi, CNF3)); - - return 0; -} - -static int mcp251x_setup(struct net_device *net, struct mcp251x_priv *priv, - struct spi_device *spi) -{ - mcp251x_do_set_bittiming(net); - - /* Enable RX0->RX1 buffer roll over and disable filters */ - mcp251x_write_bits(spi, RXBCTRL(0), - RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1, - RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1); - mcp251x_write_bits(spi, RXBCTRL(1), - RXBCTRL_RXM0 | RXBCTRL_RXM1, - RXBCTRL_RXM0 | RXBCTRL_RXM1); - return 0; -} - -static void mcp251x_hw_reset(struct spi_device *spi) -{ - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - int ret; - - mutex_lock(&priv->spi_lock); - - priv->spi_tx_buf[0] = INSTRUCTION_RESET; - - ret = spi_write(spi, priv->spi_tx_buf, 1); - - mutex_unlock(&priv->spi_lock); - - if (ret) - dev_err(&spi->dev, "reset failed: ret = %d\n", ret); - /* Wait for reset to finish */ - mdelay(10); -} - -static int mcp251x_hw_probe(struct spi_device *spi) -{ - int st1, st2; - - mcp251x_hw_reset(spi); - - /* - * Please note that these are "magic values" based on after - * reset defaults taken from data sheet which allows us to see - * if we really have a chip on the bus (we avoid common all - * zeroes or all ones situations) - */ - st1 = mcp251x_read_reg(spi, CANSTAT) & 0xEE; - st2 = mcp251x_read_reg(spi, CANCTRL) & 0x17; - - dev_dbg(&spi->dev, "CANSTAT 0x%02x CANCTRL 0x%02x\n", st1, st2); - - /* Check for power up default values */ - return (st1 == 0x80 && st2 == 0x07) ? 1 : 0; -} - -static irqreturn_t mcp251x_can_isr(int irq, void *dev_id) -{ - struct net_device *net = (struct net_device *)dev_id; - struct mcp251x_priv *priv = netdev_priv(net); - - /* Schedule bottom half */ - if (!work_pending(&priv->irq_work)) - queue_work(priv->wq, &priv->irq_work); - - return IRQ_HANDLED; -} - -static int mcp251x_open(struct net_device *net) -{ - struct mcp251x_priv *priv = netdev_priv(net); - struct spi_device *spi = priv->spi; - struct mcp251x_platform_data *pdata = spi->dev.platform_data; - int ret; - - ret = open_candev(net); - if (ret) { - dev_err(&spi->dev, "unable to set initial baudrate!\n"); - return ret; - } - - if (pdata->transceiver_enable) - pdata->transceiver_enable(1); - - priv->force_quit = 0; - priv->tx_skb = NULL; - priv->tx_len = 0; - - ret = request_irq(spi->irq, mcp251x_can_isr, - IRQF_TRIGGER_FALLING, DEVICE_NAME, net); - if (ret) { - dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq); - if (pdata->transceiver_enable) - pdata->transceiver_enable(0); - close_candev(net); - return ret; - } - - mcp251x_hw_wakeup(spi); - mcp251x_hw_reset(spi); - ret = mcp251x_setup(net, priv, spi); - if (ret) { - free_irq(spi->irq, net); - mcp251x_hw_sleep(spi); - if (pdata->transceiver_enable) - pdata->transceiver_enable(0); - close_candev(net); - return ret; - } - mcp251x_set_normal_mode(spi); - netif_wake_queue(net); - - return 0; -} - -static int mcp251x_stop(struct net_device *net) -{ - struct mcp251x_priv *priv = netdev_priv(net); - struct spi_device *spi = priv->spi; - struct mcp251x_platform_data *pdata = spi->dev.platform_data; - - close_candev(net); - - /* Disable and clear pending interrupts */ - mcp251x_write_reg(spi, CANINTE, 0x00); - mcp251x_write_reg(spi, CANINTF, 0x00); - - priv->force_quit = 1; - free_irq(spi->irq, net); - flush_workqueue(priv->wq); - - mcp251x_write_reg(spi, TXBCTRL(0), 0); - if (priv->tx_skb || priv->tx_len) - mcp251x_clean(net); - - mcp251x_hw_sleep(spi); - - if (pdata->transceiver_enable) - pdata->transceiver_enable(0); - - priv->can.state = CAN_STATE_STOPPED; - - return 0; -} - -static void mcp251x_tx_work_handler(struct work_struct *ws) -{ - struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv, - tx_work); - struct spi_device *spi = priv->spi; - struct net_device *net = priv->net; - struct can_frame *frame; - - if (priv->tx_skb) { - frame = (struct can_frame *)priv->tx_skb->data; - - if (priv->can.state == CAN_STATE_BUS_OFF) { - mcp251x_clean(net); - netif_wake_queue(net); - return; - } - if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN) - frame->can_dlc = CAN_FRAME_MAX_DATA_LEN; - mcp251x_hw_tx(spi, frame, 0); - priv->tx_len = 1 + frame->can_dlc; - can_put_echo_skb(priv->tx_skb, net, 0); - priv->tx_skb = NULL; - } -} - -static void mcp251x_irq_work_handler(struct work_struct *ws) -{ - struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv, - irq_work); - struct spi_device *spi = priv->spi; - struct net_device *net = priv->net; - u8 txbnctrl; - u8 intf; - enum can_state new_state; - - if (priv->after_suspend) { - mdelay(10); - mcp251x_hw_reset(spi); - mcp251x_setup(net, priv, spi); - if (priv->after_suspend & AFTER_SUSPEND_RESTART) { - mcp251x_set_normal_mode(spi); - } else if (priv->after_suspend & AFTER_SUSPEND_UP) { - netif_device_attach(net); - /* Clean since we lost tx buffer */ - if (priv->tx_skb || priv->tx_len) { - mcp251x_clean(net); - netif_wake_queue(net); - } - mcp251x_set_normal_mode(spi); - } else { - mcp251x_hw_sleep(spi); - } - priv->after_suspend = 0; - } - - if (priv->can.restart_ms == 0 && priv->can.state == CAN_STATE_BUS_OFF) - return; - - while (!priv->force_quit && !freezing(current)) { - u8 eflag = mcp251x_read_reg(spi, EFLG); - int can_id = 0, data1 = 0; - - mcp251x_write_reg(spi, EFLG, 0x00); - - if (priv->restart_tx) { - priv->restart_tx = 0; - mcp251x_write_reg(spi, TXBCTRL(0), 0); - if (priv->tx_skb || priv->tx_len) - mcp251x_clean(net); - netif_wake_queue(net); - can_id |= CAN_ERR_RESTARTED; - } - - if (priv->wake) { - /* Wait whilst the device wakes up */ - mdelay(10); - priv->wake = 0; - } - - intf = mcp251x_read_reg(spi, CANINTF); - mcp251x_write_bits(spi, CANINTF, intf, 0x00); - - /* Update can state */ - if (eflag & EFLG_TXBO) { - new_state = CAN_STATE_BUS_OFF; - can_id |= CAN_ERR_BUSOFF; - } else if (eflag & EFLG_TXEP) { - new_state = CAN_STATE_ERROR_PASSIVE; - can_id |= CAN_ERR_CRTL; - data1 |= CAN_ERR_CRTL_TX_PASSIVE; - } else if (eflag & EFLG_RXEP) { - new_state = CAN_STATE_ERROR_PASSIVE; - can_id |= CAN_ERR_CRTL; - data1 |= CAN_ERR_CRTL_RX_PASSIVE; - } else if (eflag & EFLG_TXWAR) { - new_state = CAN_STATE_ERROR_WARNING; - can_id |= CAN_ERR_CRTL; - data1 |= CAN_ERR_CRTL_TX_WARNING; - } else if (eflag & EFLG_RXWAR) { - new_state = CAN_STATE_ERROR_WARNING; - can_id |= CAN_ERR_CRTL; - data1 |= CAN_ERR_CRTL_RX_WARNING; - } else { - new_state = CAN_STATE_ERROR_ACTIVE; - } - - /* Update can state statistics */ - switch (priv->can.state) { - case CAN_STATE_ERROR_ACTIVE: - if (new_state >= CAN_STATE_ERROR_WARNING && - new_state <= CAN_STATE_BUS_OFF) - priv->can.can_stats.error_warning++; - case CAN_STATE_ERROR_WARNING: /* fallthrough */ - if (new_state >= CAN_STATE_ERROR_PASSIVE && - new_state <= CAN_STATE_BUS_OFF) - priv->can.can_stats.error_passive++; - break; - default: - break; - } - priv->can.state = new_state; - - if ((intf & CANINTF_ERRIF) || (can_id & CAN_ERR_RESTARTED)) { - struct sk_buff *skb; - struct can_frame *frame; - - /* Create error frame */ - skb = alloc_can_err_skb(net, &frame); - if (skb) { - /* Set error frame flags based on bus state */ - frame->can_id = can_id; - frame->data[1] = data1; - - /* Update net stats for overflows */ - if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) { - if (eflag & EFLG_RX0OVR) - net->stats.rx_over_errors++; - if (eflag & EFLG_RX1OVR) - net->stats.rx_over_errors++; - frame->can_id |= CAN_ERR_CRTL; - frame->data[1] |= - CAN_ERR_CRTL_RX_OVERFLOW; - } - - netif_rx(skb); - } else { - dev_info(&spi->dev, - "cannot allocate error skb\n"); - } - } - - if (priv->can.state == CAN_STATE_BUS_OFF) { - if (priv->can.restart_ms == 0) { - can_bus_off(net); - mcp251x_hw_sleep(spi); - return; - } - } - - if (intf == 0) - break; - - if (intf & CANINTF_WAKIF) - complete(&priv->awake); - - if (intf & CANINTF_MERRF) { - /* If there are pending Tx buffers, restart queue */ - txbnctrl = mcp251x_read_reg(spi, TXBCTRL(0)); - if (!(txbnctrl & TXBCTRL_TXREQ)) { - if (priv->tx_skb || priv->tx_len) - mcp251x_clean(net); - netif_wake_queue(net); - } - } - - if (intf & (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF)) { - net->stats.tx_packets++; - net->stats.tx_bytes += priv->tx_len - 1; - if (priv->tx_len) { - can_get_echo_skb(net, 0); - priv->tx_len = 0; - } - netif_wake_queue(net); - } - - if (intf & CANINTF_RX0IF) - mcp251x_hw_rx(spi, 0); - - if (intf & CANINTF_RX1IF) - mcp251x_hw_rx(spi, 1); - } -} - -static const struct net_device_ops mcp251x_netdev_ops = { - .ndo_open = mcp251x_open, - .ndo_stop = mcp251x_stop, - .ndo_start_xmit = mcp251x_hard_start_xmit, -}; - -static int __devinit mcp251x_can_probe(struct spi_device *spi) -{ - struct net_device *net; - struct mcp251x_priv *priv; - struct mcp251x_platform_data *pdata = spi->dev.platform_data; - int ret = -ENODEV; - - if (!pdata) - /* Platform data is required for osc freq */ - goto error_out; - - /* Allocate can/net device */ - net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX); - if (!net) { - ret = -ENOMEM; - goto error_alloc; - } - - net->netdev_ops = &mcp251x_netdev_ops; - net->flags |= IFF_ECHO; - - priv = netdev_priv(net); - priv->can.bittiming_const = &mcp251x_bittiming_const; - priv->can.do_set_mode = mcp251x_do_set_mode; - priv->can.clock.freq = pdata->oscillator_frequency / 2; - priv->net = net; - dev_set_drvdata(&spi->dev, priv); - - priv->spi = spi; - mutex_init(&priv->spi_lock); - - /* If requested, allocate DMA buffers */ - if (mcp251x_enable_dma) { - spi->dev.coherent_dma_mask = ~0; - - /* - * Minimum coherent DMA allocation is PAGE_SIZE, so allocate - * that much and share it between Tx and Rx DMA buffers. - */ - priv->spi_tx_buf = dma_alloc_coherent(&spi->dev, - PAGE_SIZE, - &priv->spi_tx_dma, - GFP_DMA); - - if (priv->spi_tx_buf) { - priv->spi_rx_buf = (u8 *)(priv->spi_tx_buf + - (PAGE_SIZE / 2)); - priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma + - (PAGE_SIZE / 2)); - } else { - /* Fall back to non-DMA */ - mcp251x_enable_dma = 0; - } - } - - /* Allocate non-DMA buffers */ - if (!mcp251x_enable_dma) { - priv->spi_tx_buf = kmalloc(SPI_TRANSFER_BUF_LEN, GFP_KERNEL); - if (!priv->spi_tx_buf) { - ret = -ENOMEM; - goto error_tx_buf; - } - priv->spi_rx_buf = kmalloc(SPI_TRANSFER_BUF_LEN, GFP_KERNEL); - if (!priv->spi_tx_buf) { - ret = -ENOMEM; - goto error_rx_buf; - } - } - - if (pdata->power_enable) - pdata->power_enable(1); - - /* Call out to platform specific setup */ - if (pdata->board_specific_setup) - pdata->board_specific_setup(spi); - - SET_NETDEV_DEV(net, &spi->dev); - - priv->wq = create_freezeable_workqueue("mcp251x_wq"); - - INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler); - INIT_WORK(&priv->irq_work, mcp251x_irq_work_handler); - - init_completion(&priv->awake); - - /* Configure the SPI bus */ - spi->mode = SPI_MODE_0; - spi->bits_per_word = 8; - spi_setup(spi); - - if (!mcp251x_hw_probe(spi)) { - dev_info(&spi->dev, "Probe failed\n"); - goto error_probe; - } - mcp251x_hw_sleep(spi); - - if (pdata->transceiver_enable) - pdata->transceiver_enable(0); - - ret = register_candev(net); - if (!ret) { - dev_info(&spi->dev, "probed\n"); - return ret; - } -error_probe: - if (!mcp251x_enable_dma) - kfree(priv->spi_rx_buf); -error_rx_buf: - if (!mcp251x_enable_dma) - kfree(priv->spi_tx_buf); -error_tx_buf: - free_candev(net); - if (mcp251x_enable_dma) - dma_free_coherent(&spi->dev, PAGE_SIZE, - priv->spi_tx_buf, priv->spi_tx_dma); -error_alloc: - if (pdata->power_enable) - pdata->power_enable(0); - dev_err(&spi->dev, "probe failed\n"); -error_out: - return ret; -} - -static int __devexit mcp251x_can_remove(struct spi_device *spi) -{ - struct mcp251x_platform_data *pdata = spi->dev.platform_data; - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - struct net_device *net = priv->net; - - unregister_candev(net); - free_candev(net); - - priv->force_quit = 1; - flush_workqueue(priv->wq); - destroy_workqueue(priv->wq); - - if (mcp251x_enable_dma) { - dma_free_coherent(&spi->dev, PAGE_SIZE, - priv->spi_tx_buf, priv->spi_tx_dma); - } else { - kfree(priv->spi_tx_buf); - kfree(priv->spi_rx_buf); - } - - if (pdata->power_enable) - pdata->power_enable(0); - - return 0; -} - -#ifdef CONFIG_PM -static int mcp251x_can_suspend(struct spi_device *spi, pm_message_t state) -{ - struct mcp251x_platform_data *pdata = spi->dev.platform_data; - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - struct net_device *net = priv->net; - - if (netif_running(net)) { - netif_device_detach(net); - - mcp251x_hw_sleep(spi); - if (pdata->transceiver_enable) - pdata->transceiver_enable(0); - priv->after_suspend = AFTER_SUSPEND_UP; - } else { - priv->after_suspend = AFTER_SUSPEND_DOWN; - } - - if (pdata->power_enable) { - pdata->power_enable(0); - priv->after_suspend |= AFTER_SUSPEND_POWER; - } - - return 0; -} - -static int mcp251x_can_resume(struct spi_device *spi) -{ - struct mcp251x_platform_data *pdata = spi->dev.platform_data; - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - - if (priv->after_suspend & AFTER_SUSPEND_POWER) { - pdata->power_enable(1); - queue_work(priv->wq, &priv->irq_work); - } else { - if (priv->after_suspend & AFTER_SUSPEND_UP) { - if (pdata->transceiver_enable) - pdata->transceiver_enable(1); - queue_work(priv->wq, &priv->irq_work); - } else { - priv->after_suspend = 0; - } - } - return 0; -} -#else -#define mcp251x_can_suspend NULL -#define mcp251x_can_resume NULL -#endif - -static struct spi_driver mcp251x_can_driver = { - .driver = { - .name = DEVICE_NAME, - .bus = &spi_bus_type, - .owner = THIS_MODULE, - }, - - .probe = mcp251x_can_probe, - .remove = __devexit_p(mcp251x_can_remove), - .suspend = mcp251x_can_suspend, - .resume = mcp251x_can_resume, -}; - -static int __init mcp251x_can_init(void) -{ - return spi_register_driver(&mcp251x_can_driver); -} - -static void __exit mcp251x_can_exit(void) -{ - spi_unregister_driver(&mcp251x_can_driver); -} - -module_init(mcp251x_can_init); -module_exit(mcp251x_can_exit); - -MODULE_AUTHOR("Chris Elston <celston@katalix.com>, " - "Christian Pellegrin <chripell@evolware.org>"); -MODULE_DESCRIPTION("Microchip 251x CAN driver"); -MODULE_LICENSE("GPL v2"); |