diff options
Diffstat (limited to 'drivers/net/can/flexcan.c')
| -rw-r--r-- | drivers/net/can/flexcan.c | 1030 |
1 files changed, 1030 insertions, 0 deletions
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c new file mode 100644 index 0000000..ef443a0 --- /dev/null +++ b/drivers/net/can/flexcan.c @@ -0,0 +1,1030 @@ +/* + * flexcan.c - FLEXCAN CAN controller driver + * + * Copyright (c) 2005-2006 Varma Electronics Oy + * Copyright (c) 2009 Sascha Hauer, Pengutronix + * Copyright (c) 2010 Marc Kleine-Budde, Pengutronix + * + * Based on code originally by Andrey Volkov <avolkov@varma-el.com> + * + * LICENCE: + * 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 version 2. + * + * 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/netdevice.h> +#include <linux/can.h> +#include <linux/can/dev.h> +#include <linux/can/error.h> +#include <linux/can/platform/flexcan.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/if_arp.h> +#include <linux/if_ether.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +#include <mach/clock.h> + +#define DRV_NAME "flexcan" + +/* 8 for RX fifo and 2 error handling */ +#define FLEXCAN_NAPI_WEIGHT (8 + 2) + +/* FLEXCAN module configuration register (CANMCR) bits */ +#define FLEXCAN_MCR_MDIS BIT(31) +#define FLEXCAN_MCR_FRZ BIT(30) +#define FLEXCAN_MCR_FEN BIT(29) +#define FLEXCAN_MCR_HALT BIT(28) +#define FLEXCAN_MCR_NOT_RDY BIT(27) +#define FLEXCAN_MCR_WAK_MSK BIT(26) +#define FLEXCAN_MCR_SOFTRST BIT(25) +#define FLEXCAN_MCR_FRZ_ACK BIT(24) +#define FLEXCAN_MCR_SUPV BIT(23) +#define FLEXCAN_MCR_SLF_WAK BIT(22) +#define FLEXCAN_MCR_WRN_EN BIT(21) +#define FLEXCAN_MCR_LPM_ACK BIT(20) +#define FLEXCAN_MCR_WAK_SRC BIT(19) +#define FLEXCAN_MCR_DOZE BIT(18) +#define FLEXCAN_MCR_SRX_DIS BIT(17) +#define FLEXCAN_MCR_BCC BIT(16) +#define FLEXCAN_MCR_LPRIO_EN BIT(13) +#define FLEXCAN_MCR_AEN BIT(12) +#define FLEXCAN_MCR_MAXMB(x) ((x) & 0xf) +#define FLEXCAN_MCR_IDAM_A (0 << 8) +#define FLEXCAN_MCR_IDAM_B (1 << 8) +#define FLEXCAN_MCR_IDAM_C (2 << 8) +#define FLEXCAN_MCR_IDAM_D (3 << 8) + +/* FLEXCAN control register (CANCTRL) bits */ +#define FLEXCAN_CTRL_PRESDIV(x) (((x) & 0xff) << 24) +#define FLEXCAN_CTRL_RJW(x) (((x) & 0x03) << 22) +#define FLEXCAN_CTRL_PSEG1(x) (((x) & 0x07) << 19) +#define FLEXCAN_CTRL_PSEG2(x) (((x) & 0x07) << 16) +#define FLEXCAN_CTRL_BOFF_MSK BIT(15) +#define FLEXCAN_CTRL_ERR_MSK BIT(14) +#define FLEXCAN_CTRL_CLK_SRC BIT(13) +#define FLEXCAN_CTRL_LPB BIT(12) +#define FLEXCAN_CTRL_TWRN_MSK BIT(11) +#define FLEXCAN_CTRL_RWRN_MSK BIT(10) +#define FLEXCAN_CTRL_SMP BIT(7) +#define FLEXCAN_CTRL_BOFF_REC BIT(6) +#define FLEXCAN_CTRL_TSYN BIT(5) +#define FLEXCAN_CTRL_LBUF BIT(4) +#define FLEXCAN_CTRL_LOM BIT(3) +#define FLEXCAN_CTRL_PROPSEG(x) ((x) & 0x07) +#define FLEXCAN_CTRL_ERR_BUS (FLEXCAN_CTRL_ERR_MSK) +#define FLEXCAN_CTRL_ERR_STATE \ + (FLEXCAN_CTRL_TWRN_MSK | FLEXCAN_CTRL_RWRN_MSK | \ + FLEXCAN_CTRL_BOFF_MSK) +#define FLEXCAN_CTRL_ERR_ALL \ + (FLEXCAN_CTRL_ERR_BUS | FLEXCAN_CTRL_ERR_STATE) + +/* FLEXCAN error and status register (ESR) bits */ +#define FLEXCAN_ESR_TWRN_INT BIT(17) +#define FLEXCAN_ESR_RWRN_INT BIT(16) +#define FLEXCAN_ESR_BIT1_ERR BIT(15) +#define FLEXCAN_ESR_BIT0_ERR BIT(14) +#define FLEXCAN_ESR_ACK_ERR BIT(13) +#define FLEXCAN_ESR_CRC_ERR BIT(12) +#define FLEXCAN_ESR_FRM_ERR BIT(11) +#define FLEXCAN_ESR_STF_ERR BIT(10) +#define FLEXCAN_ESR_TX_WRN BIT(9) +#define FLEXCAN_ESR_RX_WRN BIT(8) +#define FLEXCAN_ESR_IDLE BIT(7) +#define FLEXCAN_ESR_TXRX BIT(6) +#define FLEXCAN_EST_FLT_CONF_SHIFT (4) +#define FLEXCAN_ESR_FLT_CONF_MASK (0x3 << FLEXCAN_EST_FLT_CONF_SHIFT) +#define FLEXCAN_ESR_FLT_CONF_ACTIVE (0x0 << FLEXCAN_EST_FLT_CONF_SHIFT) +#define FLEXCAN_ESR_FLT_CONF_PASSIVE (0x1 << FLEXCAN_EST_FLT_CONF_SHIFT) +#define FLEXCAN_ESR_BOFF_INT BIT(2) +#define FLEXCAN_ESR_ERR_INT BIT(1) +#define FLEXCAN_ESR_WAK_INT BIT(0) +#define FLEXCAN_ESR_ERR_BUS \ + (FLEXCAN_ESR_BIT1_ERR | FLEXCAN_ESR_BIT0_ERR | \ + FLEXCAN_ESR_ACK_ERR | FLEXCAN_ESR_CRC_ERR | \ + FLEXCAN_ESR_FRM_ERR | FLEXCAN_ESR_STF_ERR) +#define FLEXCAN_ESR_ERR_STATE \ + (FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | FLEXCAN_ESR_BOFF_INT) +#define FLEXCAN_ESR_ERR_ALL \ + (FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE) + +/* FLEXCAN interrupt flag register (IFLAG) bits */ +#define FLEXCAN_TX_BUF_ID 8 +#define FLEXCAN_IFLAG_BUF(x) BIT(x) +#define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW BIT(7) +#define FLEXCAN_IFLAG_RX_FIFO_WARN BIT(6) +#define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE BIT(5) +#define FLEXCAN_IFLAG_DEFAULT \ + (FLEXCAN_IFLAG_RX_FIFO_OVERFLOW | FLEXCAN_IFLAG_RX_FIFO_AVAILABLE | \ + FLEXCAN_IFLAG_BUF(FLEXCAN_TX_BUF_ID)) + +/* FLEXCAN message buffers */ +#define FLEXCAN_MB_CNT_CODE(x) (((x) & 0xf) << 24) +#define FLEXCAN_MB_CNT_SRR BIT(22) +#define FLEXCAN_MB_CNT_IDE BIT(21) +#define FLEXCAN_MB_CNT_RTR BIT(20) +#define FLEXCAN_MB_CNT_LENGTH(x) (((x) & 0xf) << 16) +#define FLEXCAN_MB_CNT_TIMESTAMP(x) ((x) & 0xffff) + +#define FLEXCAN_MB_CODE_MASK (0xf0ffffff) + +/* Structure of the message buffer */ +struct flexcan_mb { + u32 can_ctrl; + u32 can_id; + u32 data[2]; +}; + +/* Structure of the hardware registers */ +struct flexcan_regs { + u32 mcr; /* 0x00 */ + u32 ctrl; /* 0x04 */ + u32 timer; /* 0x08 */ + u32 _reserved1; /* 0x0c */ + u32 rxgmask; /* 0x10 */ + u32 rx14mask; /* 0x14 */ + u32 rx15mask; /* 0x18 */ + u32 ecr; /* 0x1c */ + u32 esr; /* 0x20 */ + u32 imask2; /* 0x24 */ + u32 imask1; /* 0x28 */ + u32 iflag2; /* 0x2c */ + u32 iflag1; /* 0x30 */ + u32 _reserved2[19]; + struct flexcan_mb cantxfg[64]; +}; + +struct flexcan_priv { + struct can_priv can; + struct net_device *dev; + struct napi_struct napi; + + void __iomem *base; + u32 reg_esr; + u32 reg_ctrl_default; + + struct clk *clk; + struct flexcan_platform_data *pdata; +}; + +static struct can_bittiming_const flexcan_bittiming_const = { + .name = DRV_NAME, + .tseg1_min = 4, + .tseg1_max = 16, + .tseg2_min = 2, + .tseg2_max = 8, + .sjw_max = 4, + .brp_min = 1, + .brp_max = 256, + .brp_inc = 1, +}; + +/* + * Swtich transceiver on or off + */ +static void flexcan_transceiver_switch(const struct flexcan_priv *priv, int on) +{ + if (priv->pdata && priv->pdata->transceiver_switch) + priv->pdata->transceiver_switch(on); +} + +static inline int flexcan_has_and_handle_berr(const struct flexcan_priv *priv, + u32 reg_esr) +{ + return (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) && + (reg_esr & FLEXCAN_ESR_ERR_BUS); +} + +static inline void flexcan_chip_enable(struct flexcan_priv *priv) +{ + struct flexcan_regs __iomem *regs = priv->base; + u32 reg; + + reg = readl(®s->mcr); + reg &= ~FLEXCAN_MCR_MDIS; + writel(reg, ®s->mcr); + + udelay(10); +} + +static inline void flexcan_chip_disable(struct flexcan_priv *priv) +{ + struct flexcan_regs __iomem *regs = priv->base; + u32 reg; + + reg = readl(®s->mcr); + reg |= FLEXCAN_MCR_MDIS; + writel(reg, ®s->mcr); +} + +static int flexcan_get_berr_counter(const struct net_device *dev, + struct can_berr_counter *bec) +{ + const struct flexcan_priv *priv = netdev_priv(dev); + struct flexcan_regs __iomem *regs = priv->base; + u32 reg = readl(®s->ecr); + + bec->txerr = (reg >> 0) & 0xff; + bec->rxerr = (reg >> 8) & 0xff; + + return 0; +} + +static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev) +{ + const struct flexcan_priv *priv = netdev_priv(dev); + struct net_device_stats *stats = &dev->stats; + struct flexcan_regs __iomem *regs = priv->base; + struct can_frame *cf = (struct can_frame *)skb->data; + u32 can_id; + u32 ctrl = FLEXCAN_MB_CNT_CODE(0xc) | (cf->can_dlc << 16); + + if (can_dropped_invalid_skb(dev, skb)) + return NETDEV_TX_OK; + + netif_stop_queue(dev); + + if (cf->can_id & CAN_EFF_FLAG) { + can_id = cf->can_id & CAN_EFF_MASK; + ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR; + } else { + can_id = (cf->can_id & CAN_SFF_MASK) << 18; + } + + if (cf->can_id & CAN_RTR_FLAG) + ctrl |= FLEXCAN_MB_CNT_RTR; + + if (cf->can_dlc > 0) { + u32 data = be32_to_cpup((__be32 *)&cf->data[0]); + writel(data, ®s->cantxfg[FLEXCAN_TX_BUF_ID].data[0]); + } + if (cf->can_dlc > 3) { + u32 data = be32_to_cpup((__be32 *)&cf->data[4]); + writel(data, ®s->cantxfg[FLEXCAN_TX_BUF_ID].data[1]); + } + + writel(can_id, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_id); + writel(ctrl, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl); + + kfree_skb(skb); + + /* tx_packets is incremented in flexcan_irq */ + stats->tx_bytes += cf->can_dlc; + + return NETDEV_TX_OK; +} + +static void do_bus_err(struct net_device *dev, + struct can_frame *cf, u32 reg_esr) +{ + struct flexcan_priv *priv = netdev_priv(dev); + int rx_errors = 0, tx_errors = 0; + + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; + + if (reg_esr & FLEXCAN_ESR_BIT1_ERR) { + dev_dbg(dev->dev.parent, "BIT1_ERR irq\n"); + cf->data[2] |= CAN_ERR_PROT_BIT1; + tx_errors = 1; + } + if (reg_esr & FLEXCAN_ESR_BIT0_ERR) { + dev_dbg(dev->dev.parent, "BIT0_ERR irq\n"); + cf->data[2] |= CAN_ERR_PROT_BIT0; + tx_errors = 1; + } + if (reg_esr & FLEXCAN_ESR_ACK_ERR) { + dev_dbg(dev->dev.parent, "ACK_ERR irq\n"); + cf->can_id |= CAN_ERR_ACK; + cf->data[3] |= CAN_ERR_PROT_LOC_ACK; + tx_errors = 1; + } + if (reg_esr & FLEXCAN_ESR_CRC_ERR) { + dev_dbg(dev->dev.parent, "CRC_ERR irq\n"); + cf->data[2] |= CAN_ERR_PROT_BIT; + cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ; + rx_errors = 1; + } + if (reg_esr & FLEXCAN_ESR_FRM_ERR) { + dev_dbg(dev->dev.parent, "FRM_ERR irq\n"); + cf->data[2] |= CAN_ERR_PROT_FORM; + rx_errors = 1; + } + if (reg_esr & FLEXCAN_ESR_STF_ERR) { + dev_dbg(dev->dev.parent, "STF_ERR irq\n"); + cf->data[2] |= CAN_ERR_PROT_STUFF; + rx_errors = 1; + } + + priv->can.can_stats.bus_error++; + if (rx_errors) + dev->stats.rx_errors++; + if (tx_errors) + dev->stats.tx_errors++; +} + +static int flexcan_poll_bus_err(struct net_device *dev, u32 reg_esr) +{ + struct sk_buff *skb; + struct can_frame *cf; + + skb = alloc_can_err_skb(dev, &cf); + if (unlikely(!skb)) + return 0; + + do_bus_err(dev, cf, reg_esr); + netif_receive_skb(skb); + + dev->stats.rx_packets++; + dev->stats.rx_bytes += cf->can_dlc; + + return 1; +} + +static void do_state(struct net_device *dev, + struct can_frame *cf, enum can_state new_state) +{ + struct flexcan_priv *priv = netdev_priv(dev); + struct can_berr_counter bec; + + flexcan_get_berr_counter(dev, &bec); + + switch (priv->can.state) { + case CAN_STATE_ERROR_ACTIVE: + /* + * from: ERROR_ACTIVE + * to : ERROR_WARNING, ERROR_PASSIVE, BUS_OFF + * => : there was a warning int + */ + if (new_state >= CAN_STATE_ERROR_WARNING && + new_state <= CAN_STATE_BUS_OFF) { + dev_dbg(dev->dev.parent, "Error Warning IRQ\n"); + priv->can.can_stats.error_warning++; + + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] = (bec.txerr > bec.rxerr) ? + CAN_ERR_CRTL_TX_WARNING : + CAN_ERR_CRTL_RX_WARNING; + } + case CAN_STATE_ERROR_WARNING: /* fallthrough */ + /* + * from: ERROR_ACTIVE, ERROR_WARNING + * to : ERROR_PASSIVE, BUS_OFF + * => : error passive int + */ + if (new_state >= CAN_STATE_ERROR_PASSIVE && + new_state <= CAN_STATE_BUS_OFF) { + dev_dbg(dev->dev.parent, "Error Passive IRQ\n"); + priv->can.can_stats.error_passive++; + + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] = (bec.txerr > bec.rxerr) ? + CAN_ERR_CRTL_TX_PASSIVE : + CAN_ERR_CRTL_RX_PASSIVE; + } + break; + case CAN_STATE_BUS_OFF: + dev_err(dev->dev.parent, + "BUG! hardware recovered automatically from BUS_OFF\n"); + break; + default: + break; + } + + /* process state changes depending on the new state */ + switch (new_state) { + case CAN_STATE_ERROR_ACTIVE: + dev_dbg(dev->dev.parent, "Error Active\n"); + cf->can_id |= CAN_ERR_PROT; + cf->data[2] = CAN_ERR_PROT_ACTIVE; + break; + case CAN_STATE_BUS_OFF: + cf->can_id |= CAN_ERR_BUSOFF; + can_bus_off(dev); + break; + default: + break; + } +} + +static int flexcan_poll_state(struct net_device *dev, u32 reg_esr) +{ + struct flexcan_priv *priv = netdev_priv(dev); + struct sk_buff *skb; + struct can_frame *cf; + enum can_state new_state; + int flt; + + flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK; + if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) { + if (likely(!(reg_esr & (FLEXCAN_ESR_TX_WRN | + FLEXCAN_ESR_RX_WRN)))) + new_state = CAN_STATE_ERROR_ACTIVE; + else + new_state = CAN_STATE_ERROR_WARNING; + } else if (unlikely(flt == FLEXCAN_ESR_FLT_CONF_PASSIVE)) + new_state = CAN_STATE_ERROR_PASSIVE; + else + new_state = CAN_STATE_BUS_OFF; + + /* state hasn't changed */ + if (likely(new_state == priv->can.state)) + return 0; + + skb = alloc_can_err_skb(dev, &cf); + if (unlikely(!skb)) + return 0; + + do_state(dev, cf, new_state); + priv->can.state = new_state; + netif_receive_skb(skb); + + dev->stats.rx_packets++; + dev->stats.rx_bytes += cf->can_dlc; + + return 1; +} + +static void flexcan_read_fifo(const struct net_device *dev, + struct can_frame *cf) +{ + const struct flexcan_priv *priv = netdev_priv(dev); + struct flexcan_regs __iomem *regs = priv->base; + struct flexcan_mb __iomem *mb = ®s->cantxfg[0]; + u32 reg_ctrl, reg_id; + + reg_ctrl = readl(&mb->can_ctrl); + reg_id = readl(&mb->can_id); + if (reg_ctrl & FLEXCAN_MB_CNT_IDE) + cf->can_id = ((reg_id >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG; + else + cf->can_id = (reg_id >> 18) & CAN_SFF_MASK; + + if (reg_ctrl & FLEXCAN_MB_CNT_RTR) + cf->can_id |= CAN_RTR_FLAG; + cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf); + + *(__be32 *)(cf->data + 0) = cpu_to_be32(readl(&mb->data[0])); + *(__be32 *)(cf->data + 4) = cpu_to_be32(readl(&mb->data[1])); + + /* mark as read */ + writel(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, ®s->iflag1); + readl(®s->timer); +} + +static int flexcan_read_frame(struct net_device *dev) +{ + struct net_device_stats *stats = &dev->stats; + struct can_frame *cf; + struct sk_buff *skb; + + skb = alloc_can_skb(dev, &cf); + if (unlikely(!skb)) { + stats->rx_dropped++; + return 0; + } + + flexcan_read_fifo(dev, cf); + netif_receive_skb(skb); + + stats->rx_packets++; + stats->rx_bytes += cf->can_dlc; + + return 1; +} + +static int flexcan_poll(struct napi_struct *napi, int quota) +{ + struct net_device *dev = napi->dev; + const struct flexcan_priv *priv = netdev_priv(dev); + struct flexcan_regs __iomem *regs = priv->base; + u32 reg_iflag1, reg_esr; + int work_done = 0; + + /* + * The error bits are cleared on read, + * use saved value from irq handler. + */ + reg_esr = readl(®s->esr) | priv->reg_esr; + + /* handle state changes */ + work_done += flexcan_poll_state(dev, reg_esr); + + /* handle RX-FIFO */ + reg_iflag1 = readl(®s->iflag1); + while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE && + work_done < quota) { + work_done += flexcan_read_frame(dev); + reg_iflag1 = readl(®s->iflag1); + } + + /* report bus errors */ + if (flexcan_has_and_handle_berr(priv, reg_esr) && work_done < quota) + work_done += flexcan_poll_bus_err(dev, reg_esr); + + if (work_done < quota) { + napi_complete(napi); + /* enable IRQs */ + writel(FLEXCAN_IFLAG_DEFAULT, ®s->imask1); + writel(priv->reg_ctrl_default, ®s->ctrl); + } + + return work_done; +} + +static irqreturn_t flexcan_irq(int irq, void *dev_id) +{ + struct net_device *dev = dev_id; + struct net_device_stats *stats = &dev->stats; + struct flexcan_priv *priv = netdev_priv(dev); + struct flexcan_regs __iomem *regs = priv->base; + u32 reg_iflag1, reg_esr; + + reg_iflag1 = readl(®s->iflag1); + reg_esr = readl(®s->esr); + writel(FLEXCAN_ESR_ERR_INT, ®s->esr); /* ACK err IRQ */ + + /* + * schedule NAPI in case of: + * - rx IRQ + * - state change IRQ + * - bus error IRQ and bus error reporting is activated + */ + if ((reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) || + (reg_esr & FLEXCAN_ESR_ERR_STATE) || + flexcan_has_and_handle_berr(priv, reg_esr)) { + /* + * The error bits are cleared on read, + * save them for later use. + */ + priv->reg_esr = reg_esr & FLEXCAN_ESR_ERR_BUS; + writel(FLEXCAN_IFLAG_DEFAULT & ~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, + ®s->imask1); + writel(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL, + ®s->ctrl); + napi_schedule(&priv->napi); + } + + /* FIFO overflow */ + if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) { + writel(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, ®s->iflag1); + dev->stats.rx_over_errors++; + dev->stats.rx_errors++; + } + + /* transmission complete interrupt */ + if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) { + /* tx_bytes is incremented in flexcan_start_xmit */ + stats->tx_packets++; + writel((1 << FLEXCAN_TX_BUF_ID), ®s->iflag1); + netif_wake_queue(dev); + } + + return IRQ_HANDLED; +} + +static void flexcan_set_bittiming(struct net_device *dev) +{ + const struct flexcan_priv *priv = netdev_priv(dev); + const struct can_bittiming *bt = &priv->can.bittiming; + struct flexcan_regs __iomem *regs = priv->base; + u32 reg; + + reg = readl(®s->ctrl); + reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) | + FLEXCAN_CTRL_RJW(0x3) | + FLEXCAN_CTRL_PSEG1(0x7) | + FLEXCAN_CTRL_PSEG2(0x7) | + FLEXCAN_CTRL_PROPSEG(0x7) | + FLEXCAN_CTRL_LPB | + FLEXCAN_CTRL_SMP | + FLEXCAN_CTRL_LOM); + + reg |= FLEXCAN_CTRL_PRESDIV(bt->brp - 1) | + FLEXCAN_CTRL_PSEG1(bt->phase_seg1 - 1) | + FLEXCAN_CTRL_PSEG2(bt->phase_seg2 - 1) | + FLEXCAN_CTRL_RJW(bt->sjw - 1) | + FLEXCAN_CTRL_PROPSEG(bt->prop_seg - 1); + + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) + reg |= FLEXCAN_CTRL_LPB; + if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) + reg |= FLEXCAN_CTRL_LOM; + if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) + reg |= FLEXCAN_CTRL_SMP; + + dev_info(dev->dev.parent, "writing ctrl=0x%08x\n", reg); + writel(reg, ®s->ctrl); + + /* print chip status */ + dev_dbg(dev->dev.parent, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__, + readl(®s->mcr), readl(®s->ctrl)); +} + +/* + * flexcan_chip_start + * + * this functions is entered with clocks enabled + * + */ +static int flexcan_chip_start(struct net_device *dev) +{ + struct flexcan_priv *priv = netdev_priv(dev); + struct flexcan_regs __iomem *regs = priv->base; + unsigned int i; + int err; + u32 reg_mcr, reg_ctrl; + + /* enable module */ + flexcan_chip_enable(priv); + + /* soft reset */ + writel(FLEXCAN_MCR_SOFTRST, ®s->mcr); + udelay(10); + + reg_mcr = readl(®s->mcr); + if (reg_mcr & FLEXCAN_MCR_SOFTRST) { + dev_err(dev->dev.parent, + "Failed to softreset can module (mcr=0x%08x)\n", + reg_mcr); + err = -ENODEV; + goto out; + } + + flexcan_set_bittiming(dev); + + /* + * MCR + * + * enable freeze + * enable fifo + * halt now + * only supervisor access + * enable warning int + * choose format C + * + */ + reg_mcr = readl(®s->mcr); + reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT | + FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN | + FLEXCAN_MCR_IDAM_C; + dev_dbg(dev->dev.parent, "%s: writing mcr=0x%08x", __func__, reg_mcr); + writel(reg_mcr, ®s->mcr); + + /* + * CTRL + * + * disable timer sync feature + * + * disable auto busoff recovery + * transmit lowest buffer first + * + * enable tx and rx warning interrupt + * enable bus off interrupt + * (== FLEXCAN_CTRL_ERR_STATE) + * + * _note_: we enable the "error interrupt" + * (FLEXCAN_CTRL_ERR_MSK), too. Otherwise we don't get any + * warning or bus passive interrupts. + */ + reg_ctrl = readl(®s->ctrl); + reg_ctrl &= ~FLEXCAN_CTRL_TSYN; + reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF | + FLEXCAN_CTRL_ERR_STATE | FLEXCAN_CTRL_ERR_MSK; + + /* save for later use */ + priv->reg_ctrl_default = reg_ctrl; + dev_dbg(dev->dev.parent, "%s: writing ctrl=0x%08x", __func__, reg_ctrl); + writel(reg_ctrl, ®s->ctrl); + + for (i = 0; i < ARRAY_SIZE(regs->cantxfg); i++) { + writel(0, ®s->cantxfg[i].can_ctrl); + writel(0, ®s->cantxfg[i].can_id); + writel(0, ®s->cantxfg[i].data[0]); + writel(0, ®s->cantxfg[i].data[1]); + + /* put MB into rx queue */ + writel(FLEXCAN_MB_CNT_CODE(0x4), ®s->cantxfg[i].can_ctrl); + } + + /* acceptance mask/acceptance code (accept everything) */ + writel(0x0, ®s->rxgmask); + writel(0x0, ®s->rx14mask); + writel(0x0, ®s->rx15mask); + + flexcan_transceiver_switch(priv, 1); + + /* synchronize with the can bus */ + reg_mcr = readl(®s->mcr); + reg_mcr &= ~FLEXCAN_MCR_HALT; + writel(reg_mcr, ®s->mcr); + + priv->can.state = CAN_STATE_ERROR_ACTIVE; + + /* enable FIFO interrupts */ + writel(FLEXCAN_IFLAG_DEFAULT, ®s->imask1); + + /* print chip status */ + dev_dbg(dev->dev.parent, "%s: reading mcr=0x%08x ctrl=0x%08x\n", + __func__, readl(®s->mcr), readl(®s->ctrl)); + + return 0; + + out: + flexcan_chip_disable(priv); + return err; +} + +/* + * flexcan_chip_stop + * + * this functions is entered with clocks enabled + * + */ +static void flexcan_chip_stop(struct net_device *dev) +{ + struct flexcan_priv *priv = netdev_priv(dev); + struct flexcan_regs __iomem *regs = priv->base; + u32 reg; + + /* Disable all interrupts */ + writel(0, ®s->imask1); + + /* Disable + halt module */ + reg = readl(®s->mcr); + reg |= FLEXCAN_MCR_MDIS | FLEXCAN_MCR_HALT; + writel(reg, ®s->mcr); + + flexcan_transceiver_switch(priv, 0); + priv->can.state = CAN_STATE_STOPPED; + + return; +} + +static int flexcan_open(struct net_device *dev) +{ + struct flexcan_priv *priv = netdev_priv(dev); + int err; + + clk_enable(priv->clk); + + err = open_candev(dev); + if (err) + goto out; + + err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev); + if (err) + goto out_close; + + /* start chip and queuing */ + err = flexcan_chip_start(dev); + if (err) + goto out_close; + napi_enable(&priv->napi); + netif_start_queue(dev); + + return 0; + + out_close: + close_candev(dev); + out: + clk_disable(priv->clk); + + return err; +} + +static int flexcan_close(struct net_device *dev) +{ + struct flexcan_priv *priv = netdev_priv(dev); + + netif_stop_queue(dev); + napi_disable(&priv->napi); + flexcan_chip_stop(dev); + + free_irq(dev->irq, dev); + clk_disable(priv->clk); + + close_candev(dev); + + return 0; +} + +static int flexcan_set_mode(struct net_device *dev, enum can_mode mode) +{ + int err; + + switch (mode) { + case CAN_MODE_START: + err = flexcan_chip_start(dev); + if (err) + return err; + + netif_wake_queue(dev); + break; + + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static const struct net_device_ops flexcan_netdev_ops = { + .ndo_open = flexcan_open, + .ndo_stop = flexcan_close, + .ndo_start_xmit = flexcan_start_xmit, +}; + +static int __devinit register_flexcandev(struct net_device *dev) +{ + struct flexcan_priv *priv = netdev_priv(dev); + struct flexcan_regs __iomem *regs = priv->base; + u32 reg, err; + + clk_enable(priv->clk); + + /* select "bus clock", chip must be disabled */ + flexcan_chip_disable(priv); + reg = readl(®s->ctrl); + reg |= FLEXCAN_CTRL_CLK_SRC; + writel(reg, ®s->ctrl); + + flexcan_chip_enable(priv); + + /* set freeze, halt and activate FIFO, restrict register access */ + reg = readl(®s->mcr); + reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | + FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV; + writel(reg, ®s->mcr); + + /* + * Currently we only support newer versions of this core + * featuring a RX FIFO. Older cores found on some Coldfire + * derivates are not yet supported. + */ + reg = readl(®s->mcr); + if (!(reg & FLEXCAN_MCR_FEN)) { + dev_err(dev->dev.parent, + "Could not enable RX FIFO, unsupported core\n"); + err = -ENODEV; + goto out; + } + + err = register_candev(dev); + + out: + /* disable core and turn off clocks */ + flexcan_chip_disable(priv); + clk_disable(priv->clk); + + return err; +} + +static void __devexit unregister_flexcandev(struct net_device *dev) +{ + unregister_candev(dev); +} + +static int __devinit flexcan_probe(struct platform_device *pdev) +{ + struct net_device *dev; + struct flexcan_priv *priv; + struct resource *mem; + struct clk *clk; + void __iomem *base; + resource_size_t mem_size; + int err, irq; + + clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) { + dev_err(&pdev->dev, "no clock defined\n"); + err = PTR_ERR(clk); + goto failed_clock; + } + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + irq = platform_get_irq(pdev, 0); + if (!mem || irq <= 0) { + err = -ENODEV; + goto failed_get; + } + + mem_size = resource_size(mem); + if (!request_mem_region(mem->start, mem_size, pdev->name)) { + err = -EBUSY; + goto failed_req; + } + + base = ioremap(mem->start, mem_size); + if (!base) { + err = -ENOMEM; + goto failed_map; + } + + dev = alloc_candev(sizeof(struct flexcan_priv), 0); + if (!dev) { + err = -ENOMEM; + goto failed_alloc; + } + + dev->netdev_ops = &flexcan_netdev_ops; + dev->irq = irq; + dev->flags |= IFF_ECHO; /* we support local echo in hardware */ + + priv = netdev_priv(dev); + priv->can.clock.freq = clk_get_rate(clk); + priv->can.bittiming_const = &flexcan_bittiming_const; + priv->can.do_set_mode = flexcan_set_mode; + priv->can.do_get_berr_counter = flexcan_get_berr_counter; + priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | + CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_3_SAMPLES | + CAN_CTRLMODE_BERR_REPORTING; + priv->base = base; + priv->dev = dev; + priv->clk = clk; + priv->pdata = pdev->dev.platform_data; + + netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT); + + dev_set_drvdata(&pdev->dev, dev); + SET_NETDEV_DEV(dev, &pdev->dev); + + err = register_flexcandev(dev); + if (err) { + dev_err(&pdev->dev, "registering netdev failed\n"); + goto failed_register; + } + + dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n", + priv->base, dev->irq); + + return 0; + + failed_register: + free_candev(dev); + failed_alloc: + iounmap(base); + failed_map: + release_mem_region(mem->start, mem_size); + failed_req: + clk_put(clk); + failed_get: + failed_clock: + return err; +} + +static int __devexit flexcan_remove(struct platform_device *pdev) +{ + struct net_device *dev = platform_get_drvdata(pdev); + struct flexcan_priv *priv = netdev_priv(dev); + struct resource *mem; + + unregister_flexcandev(dev); + platform_set_drvdata(pdev, NULL); + free_candev(dev); + iounmap(priv->base); + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + release_mem_region(mem->start, resource_size(mem)); + + clk_put(priv->clk); + + return 0; +} + +static struct platform_driver flexcan_driver = { + .driver.name = DRV_NAME, + .probe = flexcan_probe, + .remove = __devexit_p(flexcan_remove), +}; + +static int __init flexcan_init(void) +{ + pr_info("%s netdevice driver\n", DRV_NAME); + return platform_driver_register(&flexcan_driver); +} + +static void __exit flexcan_exit(void) +{ + platform_driver_unregister(&flexcan_driver); + pr_info("%s: driver removed\n", DRV_NAME); +} + +module_init(flexcan_init); +module_exit(flexcan_exit); + +MODULE_AUTHOR("Sascha Hauer <kernel@pengutronix.de>, " + "Marc Kleine-Budde <kernel@pengutronix.de>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("CAN port driver for flexcan based chip"); |
