From 6e9c5a3e7af574a47c112881e7f7df7348d54a1e Mon Sep 17 00:00:00 2001 From: Bhupesh Sharma Date: Mon, 15 Jun 2015 16:44:10 +0530 Subject: can: flexcan: Add support for non RX-FIFO mode This patch adds support for non RX-FIFO (legacy) mode in the flexcan driver. On certain SoCs, the RX-FIFO support might be broken, as a result we need to fall-back on the legacy (non RX-FIFO) mode to receive CAN frames. Signed-off-by: Bhupesh Sharma Signed-off-by: Sakar Arora Change-Id: I8b07e851b68fcca9716d02b14b6712c2da654ad5 Reviewed-on: http://git.am.freescale.net:8181/38095 Tested-by: Review Code-CDREVIEW Reviewed-by: Zhengxiong Jin diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 9ed4a54..87c1853 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -156,6 +156,9 @@ #define FLEXCAN_IFLAG_DEFAULT \ (FLEXCAN_IFLAG_RX_FIFO_OVERFLOW | FLEXCAN_IFLAG_RX_FIFO_AVAILABLE | \ FLEXCAN_IFLAG_BUF(FLEXCAN_TX_BUF_ID)) +#define FLEXCAN_IFLAG_DEFAULT_RX_MB_MODE \ + (FLEXCAN_IFLAG_BUF(FLEXCAN_TX_BUF_ID)) +#define FLEXCAN_IFLAG_RX_MB_RXMASK ((1 << FLEXCAN_TX_BUF_RESERVED) - 1) /* FLEXCAN message buffers */ #define FLEXCAN_MB_CNT_CODE(x) (((x) & 0xf) << 24) @@ -255,6 +258,7 @@ struct flexcan_priv { void __iomem *base; u32 reg_esr; u32 reg_ctrl_default; + u32 rx_msg_buf; struct clk *clk_ipg; struct clk *clk_per; @@ -306,8 +310,7 @@ static const struct can_bittiming_const flexcan_bittiming_const = { .brp_inc = 1, }; -/* - * FlexCAN module is essentially modelled as a little-endian IP in most +/* FlexCAN module is essentially modelled as a little-endian IP in most * SoCs, i.e the registers as well as the message buffer areas are * implemented in a little-endian fashion. * @@ -454,7 +457,6 @@ static int flexcan_chip_softreset(struct flexcan_priv *priv) return 0; } - static int __flexcan_get_berr_counter(const struct net_device *dev, struct can_berr_counter *bec) { @@ -716,12 +718,10 @@ static int flexcan_poll_state(struct net_device *dev, u32 reg_esr) return 1; } -static void flexcan_read_fifo(const struct net_device *dev, - struct can_frame *cf) +static void flexcan_read_can_frame(const struct flexcan_priv *priv, + struct flexcan_mb __iomem *mb, + 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 = priv->read(&mb->can_ctrl); @@ -737,14 +737,39 @@ static void flexcan_read_fifo(const struct net_device *dev, *(__be32 *)(cf->data + 0) = cpu_to_be32(priv->read(&mb->data[0])); *(__be32 *)(cf->data + 4) = cpu_to_be32(priv->read(&mb->data[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]; + + flexcan_read_can_frame(priv, mb, cf); /* mark as read */ priv->write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, ®s->iflag1); priv->read(®s->timer); } +static void flexcan_read_msg_buf(const struct net_device *dev, + struct can_frame *cf, u32 msg_buf) +{ + const struct flexcan_priv *priv = netdev_priv(dev); + struct flexcan_regs __iomem *regs = priv->base; + struct flexcan_mb __iomem *mb = ®s->cantxfg[msg_buf]; + + flexcan_read_can_frame(priv, mb, cf); + + /* mark as read */ + priv->write(BIT(msg_buf), ®s->iflag1); + priv->read(®s->timer); +} + static int flexcan_read_frame(struct net_device *dev) { + const struct flexcan_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; struct can_frame *cf; struct sk_buff *skb; @@ -755,7 +780,11 @@ static int flexcan_read_frame(struct net_device *dev) return 0; } - flexcan_read_fifo(dev, cf); + if (priv->devtype_data->features & FLEXCAN_HAS_ONLY_LEGACY_RX_SUPPORT) + flexcan_read_msg_buf(dev, cf, priv->rx_msg_buf); + else + flexcan_read_fifo(dev, cf); + netif_receive_skb(skb); stats->rx_packets++; @@ -769,9 +798,10 @@ static int flexcan_read_frame(struct net_device *dev) 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_priv *priv = netdev_priv(dev); struct flexcan_regs __iomem *regs = priv->base; u32 reg_iflag1, reg_esr; + unsigned long iflag1; int work_done = 0; /* @@ -783,12 +813,25 @@ static int flexcan_poll(struct napi_struct *napi, int quota) /* handle state changes */ work_done += flexcan_poll_state(dev, reg_esr); - /* handle RX-FIFO */ reg_iflag1 = priv->read(®s->iflag1); - while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE && - work_done < quota) { - work_done += flexcan_read_frame(dev); - reg_iflag1 = priv->read(®s->iflag1); + + if (priv->devtype_data->features & FLEXCAN_HAS_ONLY_LEGACY_RX_SUPPORT) { + /* handle legacy RX mode */ + iflag1 = reg_iflag1 & FLEXCAN_IFLAG_RX_MB_RXMASK; + while ((reg_iflag1 & FLEXCAN_IFLAG_RX_MB_RXMASK) && + work_done < quota) { + priv->rx_msg_buf = find_first_bit(&iflag1, + (FLEXCAN_TX_BUF_ID - 1)); + work_done += flexcan_read_frame(dev); + reg_iflag1 = priv->read(®s->iflag1); + } + } else { + /* handle RX-FIFO */ + while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE && + work_done < quota) { + work_done += flexcan_read_frame(dev); + reg_iflag1 = priv->read(®s->iflag1); + } } /* report bus errors */ @@ -798,7 +841,13 @@ static int flexcan_poll(struct napi_struct *napi, int quota) if (work_done < quota) { napi_complete(napi); /* enable IRQs */ - priv->write(FLEXCAN_IFLAG_DEFAULT, ®s->imask1); + if (priv->devtype_data->features & + FLEXCAN_HAS_ONLY_LEGACY_RX_SUPPORT) + priv->write(FLEXCAN_IFLAG_DEFAULT_RX_MB_MODE | + FLEXCAN_IFLAG_RX_MB_RXMASK, ®s->imask1); + else + priv->write(FLEXCAN_IFLAG_DEFAULT, ®s->imask1); + priv->write(priv->reg_ctrl_default, ®s->ctrl); } @@ -825,26 +874,44 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id) * - 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; - priv->write(FLEXCAN_IFLAG_DEFAULT & - ~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, ®s->imask1); - priv->write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL, - ®s->ctrl); - napi_schedule(&priv->napi); - } + if (priv->devtype_data->features & FLEXCAN_HAS_ONLY_LEGACY_RX_SUPPORT) { + if ((reg_iflag1 & FLEXCAN_IFLAG_RX_MB_RXMASK) || + (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; + priv->write(FLEXCAN_IFLAG_DEFAULT_RX_MB_MODE & + ~FLEXCAN_IFLAG_RX_MB_RXMASK, ®s->imask1); + priv->write(priv->reg_ctrl_default & + ~FLEXCAN_CTRL_ERR_ALL, ®s->ctrl); + + napi_schedule(&priv->napi); + } + } else { + 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; + priv->write(FLEXCAN_IFLAG_DEFAULT & + ~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, + ®s->imask1); + priv->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) { - priv->write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, ®s->iflag1); - dev->stats.rx_over_errors++; - dev->stats.rx_errors++; + /* FIFO overflow */ + if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) { + priv->write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, + ®s->iflag1); + dev->stats.rx_over_errors++; + dev->stats.rx_errors++; + } } /* transmission complete interrupt */ @@ -940,7 +1007,12 @@ static int flexcan_chip_start(struct net_device *dev) */ reg_mcr = priv->read(®s->mcr); reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff); - reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT | + if (priv->devtype_data->features & FLEXCAN_HAS_ONLY_LEGACY_RX_SUPPORT) + reg_mcr &= ~FLEXCAN_MCR_FEN; + else + reg_mcr |= FLEXCAN_MCR_FEN; + + reg_mcr |= FLEXCAN_MCR_FRZ | 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); @@ -1037,8 +1109,13 @@ static int flexcan_chip_start(struct net_device *dev) priv->can.state = CAN_STATE_ERROR_ACTIVE; - /* enable FIFO interrupts */ - priv->write(FLEXCAN_IFLAG_DEFAULT, ®s->imask1); + if (priv->devtype_data->features & FLEXCAN_HAS_ONLY_LEGACY_RX_SUPPORT) + /* enable mb interrupts */ + priv->write(FLEXCAN_IFLAG_DEFAULT_RX_MB_MODE | + FLEXCAN_IFLAG_RX_MB_RXMASK, ®s->imask1); + else + /* enable FIFO interrupts */ + priv->write(FLEXCAN_IFLAG_DEFAULT, ®s->imask1); /* print chip status */ netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__, @@ -1195,22 +1272,29 @@ static int register_flexcandev(struct net_device *dev) if (err) goto out_chip_disable; - /* set freeze, halt and activate FIFO, restrict register access */ + /* set freeze, halt and activate FIFO/legacy mode, restrict + * register access + */ reg = priv->read(®s->mcr); - reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | - FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV; + if (priv->devtype_data->features & FLEXCAN_HAS_ONLY_LEGACY_RX_SUPPORT) + reg &= ~FLEXCAN_MCR_FEN; + else + reg |= FLEXCAN_MCR_FEN; + + reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | FLEXCAN_MCR_SUPV; priv->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 = priv->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; + if (priv->devtype_data->features & FLEXCAN_HAS_ONLY_LEGACY_RX_SUPPORT) { + /* Legacy RX mode*/ + netdev_info(dev, "Legacy mode (non RX-FIFO) enabled\n"); + } else { + /* RX FIFO mode */ + reg = priv->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); -- cgit v0.10.2