/* * 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 * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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) & 0x1f) #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) #define FLEXCAN_ESR_ALL_INT \ (FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \ FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT) /* 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) #define FLEXCAN_TIMEOUT_US (50) /* * FLEXCAN hardware feature flags * * Below is some version info we got: * SOC Version IP-Version Glitch- [TR]WRN_INT * Filter? connected? * MX25 FlexCAN2 03.00.00.00 no no * MX28 FlexCAN2 03.00.04.00 yes yes * MX35 FlexCAN2 03.00.00.00 no no * MX53 FlexCAN2 03.00.00.00 yes no * MX6s FlexCAN3 10.00.12.00 yes yes * * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected. */ #define FLEXCAN_HAS_V10_FEATURES BIT(1) /* For core version >= 10 */ #define FLEXCAN_HAS_BROKEN_ERR_STATE BIT(2) /* [TR]WRN_INT not connected */ /* 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 crl2; /* 0x34 */ u32 esr2; /* 0x38 */ u32 imeur; /* 0x3c */ u32 lrfr; /* 0x40 */ u32 crcr; /* 0x44 */ u32 rxfgmask; /* 0x48 */ u32 rxfir; /* 0x4c */ u32 _reserved3[12]; struct flexcan_mb cantxfg[64]; }; struct flexcan_devtype_data { u32 features; /* hardware controller features */ }; 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_ipg; struct clk *clk_per; struct flexcan_platform_data *pdata; const struct flexcan_devtype_data *devtype_data; struct regulator *reg_xceiver; }; static struct flexcan_devtype_data fsl_p1010_devtype_data = { .features = FLEXCAN_HAS_BROKEN_ERR_STATE, }; static struct flexcan_devtype_data fsl_imx28_devtype_data; static struct flexcan_devtype_data fsl_imx6q_devtype_data = { .features = FLEXCAN_HAS_V10_FEATURES, }; static const 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, }; /* * Abstract off the read/write for arm versus ppc. This * assumes that PPC uses big-endian registers and everything * else uses little-endian registers, independent of CPU * endianess. */ #if defined(CONFIG_PPC) static inline u32 flexcan_read(void __iomem *addr) { return in_be32(addr); } static inline void flexcan_write(u32 val, void __iomem *addr) { out_be32(addr, val); } #else static inline u32 flexcan_read(void __iomem *addr) { return readl(addr); } static inline void flexcan_write(u32 val, void __iomem *addr) { writel(val, addr); } #endif static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv) { if (!priv->reg_xceiver) return 0; return regulator_enable(priv->reg_xceiver); } static inline int flexcan_transceiver_disable(const struct flexcan_priv *priv) { if (!priv->reg_xceiver) return 0; return regulator_disable(priv->reg_xceiver); } 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 int flexcan_chip_enable(struct flexcan_priv *priv) { struct flexcan_regs __iomem *regs = priv->base; unsigned int timeout = FLEXCAN_TIMEOUT_US / 10; u32 reg; reg = flexcan_read(®s->mcr); reg &= ~FLEXCAN_MCR_MDIS; flexcan_write(reg, ®s->mcr); while (timeout-- && (flexcan_read(®s->mcr) & FLEXCAN_MCR_LPM_ACK)) usleep_range(10, 20); if (flexcan_read(®s->mcr) & FLEXCAN_MCR_LPM_ACK) return -ETIMEDOUT; return 0; } static int flexcan_chip_disable(struct flexcan_priv *priv) { struct flexcan_regs __iomem *regs = priv->base; unsigned int timeout = FLEXCAN_TIMEOUT_US / 10; u32 reg; reg = flexcan_read(®s->mcr); reg |= FLEXCAN_MCR_MDIS; flexcan_write(reg, ®s->mcr); while (timeout-- && !(flexcan_read(®s->mcr) & FLEXCAN_MCR_LPM_ACK)) usleep_range(10, 20); if (!(flexcan_read(®s->mcr) & FLEXCAN_MCR_LPM_ACK)) return -ETIMEDOUT; return 0; } static int flexcan_chip_freeze(struct flexcan_priv *priv) { struct flexcan_regs __iomem *regs = priv->base; unsigned int timeout = 1000 * 1000 * 10 / priv->can.bittiming.bitrate; u32 reg; reg = flexcan_read(®s->mcr); reg |= FLEXCAN_MCR_HALT; flexcan_write(reg, ®s->mcr); while (timeout-- && !(flexcan_read(®s->mcr) & FLEXCAN_MCR_FRZ_ACK)) usleep_range(100, 200); if (!(flexcan_read(®s->mcr) & FLEXCAN_MCR_FRZ_ACK)) return -ETIMEDOUT; return 0; } static int flexcan_chip_unfreeze(struct flexcan_priv *priv) { struct flexcan_regs __iomem *regs = priv->base; unsigned int timeout = FLEXCAN_TIMEOUT_US / 10; u32 reg; reg = flexcan_read(®s->mcr); reg &= ~FLEXCAN_MCR_HALT; flexcan_write(reg, ®s->mcr); while (timeout-- && (flexcan_read(®s->mcr) & FLEXCAN_MCR_FRZ_ACK)) usleep_range(10, 20); if (flexcan_read(®s->mcr) & FLEXCAN_MCR_FRZ_ACK) return -ETIMEDOUT; return 0; } static int flexcan_chip_softreset(struct flexcan_priv *priv) { struct flexcan_regs __iomem *regs = priv->base; unsigned int timeout = FLEXCAN_TIMEOUT_US / 10; flexcan_write(FLEXCAN_MCR_SOFTRST, ®s->mcr); while (timeout-- && (flexcan_read(®s->mcr) & FLEXCAN_MCR_SOFTRST)) usleep_range(10, 20); if (flexcan_read(®s->mcr) & FLEXCAN_MCR_SOFTRST) return -ETIMEDOUT; return 0; } 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 = flexcan_read(®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 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]); flexcan_write(data, ®s->cantxfg[FLEXCAN_TX_BUF_ID].data[0]); } if (cf->can_dlc > 3) { u32 data = be32_to_cpup((__be32 *)&cf->data[4]); flexcan_write(data, ®s->cantxfg[FLEXCAN_TX_BUF_ID].data[1]); } can_put_echo_skb(skb, dev, 0); flexcan_write(can_id, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_id); flexcan_write(ctrl, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl); 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) { netdev_dbg(dev, "BIT1_ERR irq\n"); cf->data[2] |= CAN_ERR_PROT_BIT1; tx_errors = 1; } if (reg_esr & FLEXCAN_ESR_BIT0_ERR) { netdev_dbg(dev, "BIT0_ERR irq\n"); cf->data[2] |= CAN_ERR_PROT_BIT0; tx_errors = 1; } if (reg_esr & FLEXCAN_ESR_ACK_ERR) { netdev_dbg(dev, "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) { netdev_dbg(dev, "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) { netdev_dbg(dev, "FRM_ERR irq\n"); cf->data[2] |= CAN_ERR_PROT_FORM; rx_errors = 1; } if (reg_esr & FLEXCAN_ESR_STF_ERR) { netdev_dbg(dev, "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) { netdev_dbg(dev, "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) { netdev_dbg(dev, "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: netdev_err(dev, "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: netdev_dbg(dev, "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 = flexcan_read(&mb->can_ctrl); reg_id = flexcan_read(&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(flexcan_read(&mb->data[0])); *(__be32 *)(cf->data + 4) = cpu_to_be32(flexcan_read(&mb->data[1])); /* mark as read */ flexcan_write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, ®s->iflag1); flexcan_read(®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; can_led_event(dev, CAN_LED_EVENT_RX); 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 = flexcan_read(®s->esr) | priv->reg_esr; /* handle state changes */ work_done += flexcan_poll_state(dev, reg_esr); /* handle RX-FIFO */ reg_iflag1 = flexcan_read(®s->iflag1); while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE && work_done < quota) { work_done += flexcan_read_frame(dev); reg_iflag1 = flexcan_read(®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 */ flexcan_write(FLEXCAN_IFLAG_DEFAULT, ®s->imask1); flexcan_write(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 = flexcan_read(®s->iflag1); reg_esr = flexcan_read(®s->esr); /* ACK all bus error and state change IRQ sources */ if (reg_esr & FLEXCAN_ESR_ALL_INT) flexcan_write(reg_esr & FLEXCAN_ESR_ALL_INT, ®s->esr); /* * 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; flexcan_write(FLEXCAN_IFLAG_DEFAULT & ~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, ®s->imask1); flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL, ®s->ctrl); napi_schedule(&priv->napi); } /* FIFO overflow */ if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) { flexcan_write(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)) { stats->tx_bytes += can_get_echo_skb(dev, 0); stats->tx_packets++; can_led_event(dev, CAN_LED_EVENT_TX); flexcan_write((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 = flexcan_read(®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; netdev_info(dev, "writing ctrl=0x%08x\n", reg); flexcan_write(reg, ®s->ctrl); /* print chip status */ netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__, flexcan_read(®s->mcr), flexcan_read(®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; int err; u32 reg_mcr, reg_ctrl; /* enable module */ err = flexcan_chip_enable(priv); if (err) return err; /* soft reset */ err = flexcan_chip_softreset(priv); if (err) goto out_chip_disable; flexcan_set_bittiming(dev); /* * MCR * * enable freeze * enable fifo * halt now * only supervisor access * enable warning int * choose format C * disable local echo * */ reg_mcr = flexcan_read(®s->mcr); reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff); reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT | FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_SRX_DIS | FLEXCAN_MCR_MAXMB(FLEXCAN_TX_BUF_ID); netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr); flexcan_write(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) */ reg_ctrl = flexcan_read(®s->ctrl); reg_ctrl &= ~FLEXCAN_CTRL_TSYN; reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF | FLEXCAN_CTRL_ERR_STATE; /* * enable the "error interrupt" (FLEXCAN_CTRL_ERR_MSK), * on most Flexcan cores, too. Otherwise we don't get * any error warning or passive interrupts. */ if (priv->devtype_data->features & FLEXCAN_HAS_BROKEN_ERR_STATE || priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) reg_ctrl |= FLEXCAN_CTRL_ERR_MSK; /* save for later use */ priv->reg_ctrl_default = reg_ctrl; netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl); flexcan_write(reg_ctrl, ®s->ctrl); /* Abort any pending TX, mark Mailbox as INACTIVE */ flexcan_write(FLEXCAN_MB_CNT_CODE(0x4), ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl); /* acceptance mask/acceptance code (accept everything) */ flexcan_write(0x0, ®s->rxgmask); flexcan_write(0x0, ®s->rx14mask); flexcan_write(0x0, ®s->rx15mask); if (priv->devtype_data->features & FLEXCAN_HAS_V10_FEATURES) flexcan_write(0x0, ®s->rxfgmask); err = flexcan_transceiver_enable(priv); if (err) goto out_chip_disable; /* synchronize with the can bus */ err = flexcan_chip_unfreeze(priv); if (err) goto out_transceiver_disable; priv->can.state = CAN_STATE_ERROR_ACTIVE; /* enable FIFO interrupts */ flexcan_write(FLEXCAN_IFLAG_DEFAULT, ®s->imask1); /* print chip status */ netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__, flexcan_read(®s->mcr), flexcan_read(®s->ctrl)); return 0; out_transceiver_disable: flexcan_transceiver_disable(priv); out_chip_disable: 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; /* freeze + disable module */ flexcan_chip_freeze(priv); flexcan_chip_disable(priv); /* Disable all interrupts */ flexcan_write(0, ®s->imask1); flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL, ®s->ctrl); flexcan_transceiver_disable(priv); priv->can.state = CAN_STATE_STOPPED; return; } static int flexcan_open(struct net_device *dev) { struct flexcan_priv *priv = netdev_priv(dev); int err; err = clk_prepare_enable(priv->clk_ipg); if (err) return err; err = clk_prepare_enable(priv->clk_per); if (err) goto out_disable_ipg; err = open_candev(dev); if (err) goto out_disable_per; 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_free_irq; can_led_event(dev, CAN_LED_EVENT_OPEN); napi_enable(&priv->napi); netif_start_queue(dev); return 0; out_free_irq: free_irq(dev->irq, dev); out_close: close_candev(dev); out_disable_per: clk_disable_unprepare(priv->clk_per); out_disable_ipg: clk_disable_unprepare(priv->clk_ipg); 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_unprepare(priv->clk_per); clk_disable_unprepare(priv->clk_ipg); close_candev(dev); can_led_event(dev, CAN_LED_EVENT_STOP); 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 register_flexcandev(struct net_device *dev) { struct flexcan_priv *priv = netdev_priv(dev); struct flexcan_regs __iomem *regs = priv->base; u32 reg, err; err = clk_prepare_enable(priv->clk_ipg); if (err) return err; err = clk_prepare_enable(priv->clk_per); if (err) goto out_disable_ipg; /* select "bus clock", chip must be disabled */ err = flexcan_chip_disable(priv); if (err) goto out_disable_per; reg = flexcan_read(®s->ctrl); reg |= FLEXCAN_CTRL_CLK_SRC; flexcan_write(reg, ®s->ctrl); err = flexcan_chip_enable(priv); if (err) goto out_chip_disable; /* set freeze, halt and activate FIFO, restrict register access */ reg = flexcan_read(®s->mcr); reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV; flexcan_write(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 = flexcan_read(®s->mcr); if (!(reg & FLEXCAN_MCR_FEN)) { netdev_err(dev, "Could not enable RX FIFO, unsupported core\n"); err = -ENODEV; goto out_chip_disable; } err = register_candev(dev); /* disable core and turn off clocks */ out_chip_disable: flexcan_chip_disable(priv); out_disable_per: clk_disable_unprepare(priv->clk_per); out_disable_ipg: clk_disable_unprepare(priv->clk_ipg); return err; } static void unregister_flexcandev(struct net_device *dev) { unregister_candev(dev); } static const struct of_device_id flexcan_of_match[] = { { .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, }, { .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, }, { .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, flexcan_of_match); static const struct platform_device_id flexcan_id_table[] = { { .name = "flexcan", .driver_data = (kernel_ulong_t)&fsl_p1010_devtype_data, }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(platform, flexcan_id_table); static int flexcan_probe(struct platform_device *pdev) { const struct of_device_id *of_id; const struct flexcan_devtype_data *devtype_data; struct net_device *dev; struct flexcan_priv *priv; struct resource *mem; struct clk *clk_ipg = NULL, *clk_per = NULL; void __iomem *base; int err, irq; u32 clock_freq = 0; if (pdev->dev.of_node) of_property_read_u32(pdev->dev.of_node, "clock-frequency", &clock_freq); if (!clock_freq) { clk_ipg = devm_clk_get(&pdev->dev, "ipg"); if (IS_ERR(clk_ipg)) { dev_err(&pdev->dev, "no ipg clock defined\n"); return PTR_ERR(clk_ipg); } clk_per = devm_clk_get(&pdev->dev, "per"); if (IS_ERR(clk_per)) { dev_err(&pdev->dev, "no per clock defined\n"); return PTR_ERR(clk_per); } clock_freq = clk_get_rate(clk_per); } mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); irq = platform_get_irq(pdev, 0); if (irq <= 0) return -ENODEV; base = devm_ioremap_resource(&pdev->dev, mem); if (IS_ERR(base)) return PTR_ERR(base); of_id = of_match_device(flexcan_of_match, &pdev->dev); if (of_id) { devtype_data = of_id->data; } else if (pdev->id_entry->driver_data) { devtype_data = (struct flexcan_devtype_data *) pdev->id_entry->driver_data; } else { return -ENODEV; } dev = alloc_candev(sizeof(struct flexcan_priv), 1); if (!dev) return -ENOMEM; dev->netdev_ops = &flexcan_netdev_ops; dev->irq = irq; dev->flags |= IFF_ECHO; priv = netdev_priv(dev); priv->can.clock.freq = clock_freq; 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_ipg = clk_ipg; priv->clk_per = clk_per; priv->pdata = dev_get_platdata(&pdev->dev); priv->devtype_data = devtype_data; priv->reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver"); if (IS_ERR(priv->reg_xceiver)) priv->reg_xceiver = NULL; netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT); platform_set_drvdata(pdev, dev); SET_NETDEV_DEV(dev, &pdev->dev); err = register_flexcandev(dev); if (err) { dev_err(&pdev->dev, "registering netdev failed\n"); goto failed_register; } devm_can_led_init(dev); dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n", priv->base, dev->irq); return 0; failed_register: free_candev(dev); return err; } static int flexcan_remove(struct platform_device *pdev) { struct net_device *dev = platform_get_drvdata(pdev); struct flexcan_priv *priv = netdev_priv(dev); unregister_flexcandev(dev); netif_napi_del(&priv->napi); free_candev(dev); return 0; } #ifdef CONFIG_PM_SLEEP static int flexcan_suspend(struct device *device) { struct net_device *dev = dev_get_drvdata(device); struct flexcan_priv *priv = netdev_priv(dev); int err; err = flexcan_chip_disable(priv); if (err) return err; if (netif_running(dev)) { netif_stop_queue(dev); netif_device_detach(dev); } priv->can.state = CAN_STATE_SLEEPING; return 0; } static int flexcan_resume(struct device *device) { struct net_device *dev = dev_get_drvdata(device); struct flexcan_priv *priv = netdev_priv(dev); priv->can.state = CAN_STATE_ERROR_ACTIVE; if (netif_running(dev)) { netif_device_attach(dev); netif_start_queue(dev); } return flexcan_chip_enable(priv); } #endif /* CONFIG_PM_SLEEP */ static SIMPLE_DEV_PM_OPS(flexcan_pm_ops, flexcan_suspend, flexcan_resume); static struct platform_driver flexcan_driver = { .driver = { .name = DRV_NAME, .owner = THIS_MODULE, .pm = &flexcan_pm_ops, .of_match_table = flexcan_of_match, }, .probe = flexcan_probe, .remove = flexcan_remove, .id_table = flexcan_id_table, }; module_platform_driver(flexcan_driver); MODULE_AUTHOR("Sascha Hauer , " "Marc Kleine-Budde "); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("CAN port driver for flexcan based chip");