From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Hans J. Koch" Subject: [PATCH] socketcan: add a driver for FlexCAN controllers. Date: Thu, 17 Jun 2010 12:52:06 +0200 Message-ID: <20100617105201.GA2015@bluebox.local> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: socketcan-core@lists.berlios.de, Sascha Hauer To: netdev@vger.kernel.org Return-path: Received: from www.tglx.de ([62.245.132.106]:46372 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751233Ab0FQKwU (ORCPT ); Thu, 17 Jun 2010 06:52:20 -0400 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: This adds a driver for FlexCAN based CAN controllers, e.g. found in Freescale i.MX35 SoCs. The original version of this driver was posted by Sascha Hauer in July 2009: http://kerneltrap.org/mailarchive/linux-netdev/2009/7/29/6251621 I took this version, added NAPI support, and fixed some problems found during testing. Well, here is the result. Please review. Thanks, Hans Signed-off-by: Hans J. Koch --- drivers/net/can/Kconfig | 6 + drivers/net/can/Makefile | 1 + drivers/net/can/flexcan.c | 828 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 835 insertions(+), 0 deletions(-) create mode 100644 drivers/net/can/flexcan.c diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig index 2c5227c..4250c99 100644 --- a/drivers/net/can/Kconfig +++ b/drivers/net/can/Kconfig @@ -73,6 +73,12 @@ config CAN_JANZ_ICAN3 This driver can also be built as a module. If so, the module will be called janz-ican3.ko. +config CAN_FLEXCAN + tristate "Support for Freescale FLEXCAN based chips" + depends on CAN_DEV + ---help--- + Driver for Freescale FlexCAN. + source "drivers/net/can/mscan/Kconfig" source "drivers/net/can/sja1000/Kconfig" diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile index 9047cd0..0057537 100644 --- a/drivers/net/can/Makefile +++ b/drivers/net/can/Makefile @@ -16,5 +16,6 @@ obj-$(CONFIG_CAN_TI_HECC) += ti_hecc.o obj-$(CONFIG_CAN_MCP251X) += mcp251x.o obj-$(CONFIG_CAN_BFIN) += bfin_can.o obj-$(CONFIG_CAN_JANZ_ICAN3) += janz-ican3.o +obj-$(CONFIG_CAN_FLEXCAN) += flexcan.o ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c new file mode 100644 index 0000000..ab00873 --- /dev/null +++ b/drivers/net/can/flexcan.c @@ -0,0 +1,828 @@ +/* + * FLEXCAN CAN controller driver + * + * Copyright (C) 2005-2006 Varma Electronics Oy + * Copyright (C) 2009 Sascha Hauer, Pengutronix + * Copyright (C) 2010 Hans J. Koch + * + * Based on code originally by Andrey Volkov + * + * Licensed under the terms of the GPL v2. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#define DRIVER_NAME "flexcan" + +#define TX_ECHO_SKB_MAX 1 +#define FLEXCAN_DEF_NAPI_WEIGHT 6 + +/* FLEXCAN module configuration register (CANMCR) bits */ +#define CANMCR_MDIS (1 << 31) +#define CANMCR_FRZ (1 << 30) +#define CANMCR_FEN (1 << 29) +#define CANMCR_HALT (1 << 28) +#define CANMCR_NOT_RDY (1 << 27) +#define CANMCR_SOFTRST (1 << 25) +#define CANMCR_FRZACK (1 << 24) +#define CANMCR_SUPV (1 << 23) +#define CANMCR_SRX_DIS (1 << 17) +#define CANMCR_MAXMB(x) ((x) & 0x0f) +#define CANMCR_IDAM_A (0 << 8) +#define CANMCR_IDAM_B (1 << 8) +#define CANMCR_IDAM_C (2 << 8) + +/* FLEXCAN control register (CANCTRL) bits */ +#define CANCTRL_PRESDIV(x) (((x) & 0xff) << 24) +#define CANCTRL_RJW(x) (((x) & 0x03) << 22) +#define CANCTRL_PSEG1(x) (((x) & 0x07) << 19) +#define CANCTRL_PSEG2(x) (((x) & 0x07) << 16) +#define CANCTRL_BOFFMSK (1 << 15) +#define CANCTRL_ERRMSK (1 << 14) +#define CANCTRL_CLKSRC (1 << 13) +#define CANCTRL_LPB (1 << 12) +#define CANCTRL_TWRN_MSK (1 << 11) +#define CANCTRL_RWRN_MSK (1 << 10) +#define CANCTRL_SAMP (1 << 7) +#define CANCTRL_BOFFREC (1 << 6) +#define CANCTRL_TSYNC (1 << 5) +#define CANCTRL_LBUF (1 << 4) +#define CANCTRL_LOM (1 << 3) +#define CANCTRL_PROPSEG(x) ((x) & 0x07) + +/* FLEXCAN error counter register (ERRCNT) bits */ +#define ERRCNT_REXECTR(x) (((x) & 0xff) << 8) +#define ERRCNT_TXECTR(x) ((x) & 0xff) + +/* FLEXCAN error and status register (ERRSTAT) bits */ +#define ERRSTAT_TWRNINT (1 << 17) +#define ERRSTAT_RWRNINT (1 << 16) +#define ERRSTAT_BIT1ERR (1 << 15) +#define ERRSTAT_BIT0ERR (1 << 14) +#define ERRSTAT_ACKERR (1 << 13) +#define ERRSTAT_CRCERR (1 << 12) +#define ERRSTAT_FRMERR (1 << 11) +#define ERRSTAT_STFERR (1 << 10) +#define ERRSTAT_TXWRN (1 << 9) +#define ERRSTAT_RXWRN (1 << 8) +#define ERRSTAT_IDLE (1 << 7) +#define ERRSTAT_TXRX (1 << 6) +#define ERRSTAT_FLTCONF_MASK (3 << 4) +#define ERRSTAT_FLTCONF_ERROR_ACTIVE (0 << 4) +#define ERRSTAT_FLTCONF_ERROR_PASSIVE (1 << 4) +#define ERRSTAT_FLTCONF_ERROR_BUS_OFF (2 << 4) +#define ERRSTAT_BOFFINT (1 << 2) +#define ERRSTAT_ERRINT (1 << 1) +#define ERRSTAT_WAKINT (1 << 0) +#define ERRSTAT_INT (ERRSTAT_BOFFINT | ERRSTAT_ERRINT | ERRSTAT_TWRNINT | \ + ERRSTAT_RWRNINT) + +/* FLEXCAN interrupt flag register (IFLAG) bits */ +#define IFLAG_BUF(x) (1 << (x)) +#define IFLAG_RX_FIFO_OVERFLOW (1 << 7) +#define IFLAG_RX_FIFO_WARN (1 << 6) +#define IFLAG_RX_FIFO_AVAILABLE (1 << 5) + +/* FLEXCAN message buffers */ +#define MB_CNT_CODE(x) (((x) & 0xf) << 24) +#define MB_CNT_SRR (1 << 22) +#define MB_CNT_IDE (1 << 21) +#define MB_CNT_RTR (1 << 20) +#define MB_CNT_LENGTH(x) (((x) & 0xf) << 16) +#define MB_CNT_TIMESTAMP(x) ((x) & 0xffff) + +#define MB_ID_STD (0x7ff << 18) +#define MB_ID_EXT 0x1fffffff +#define MB_CODE_MASK 0xf0ffffff + +#define TX_ECHO_SKB_MAX 1 + +/* 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 canmcr; /* 0x00 */ + u32 canctrl; /* 0x04 */ + u32 timer; /* 0x08 */ + u32 reserved1; /* 0x0c */ + u32 rxgmask; /* 0x10 */ + u32 rx14mask; /* 0x14 */ + u32 rx15mask; /* 0x18 */ + u32 errcnt; /* 0x1c */ + u32 errstat; /* 0x20 */ + u32 imask2; /* 0x24 */ + u32 imask1; /* 0x28 */ + u32 iflag2; /* 0x2c */ + u32 iflag1; /* 0x30 */ + u32 reserved4[19]; + struct flexcan_mb cantxfg[64]; +}; + +struct flexcan_priv { + struct can_priv can; + void __iomem *base; + + struct net_device *dev; + struct napi_struct napi; + struct clk *clk; +}; + +static struct can_bittiming_const flexcan_bittiming_const = { + .name = DRIVER_NAME, + .tseg1_min = 1, + .tseg1_max = 16, + .tseg2_min = 2, + .tseg2_max = 8, + .sjw_max = 4, + .brp_min = 1, + .brp_max = 256, + .brp_inc = 1, +}; + +/* Mailboxes 0..7 are for RX FIFO, 8 for TX */ +#define TX_BUF_ID 8 + +static void disable_mode_on(struct flexcan_regs __iomem *regs) +{ + u32 reg = readl(®s->canmcr); + + writel(reg | CANMCR_MDIS, ®s->canmcr); + udelay(100); +} + +static void disable_mode_off(struct flexcan_regs __iomem *regs) +{ + u32 reg = readl(®s->canmcr); + + writel(reg & ~CANMCR_MDIS, ®s->canmcr); + udelay(100); +} + +static int freeze_mode_on(struct flexcan_regs __iomem *regs) +{ + u32 reg = readl(®s->canmcr); + int timeout = 10000; + + if (reg & CANMCR_FRZACK) + return 0; + + writel(reg | CANMCR_FRZ, ®s->canmcr); + writel(reg | CANMCR_HALT, ®s->canmcr); + while (!(reg & CANMCR_FRZACK)) { + if (--timeout < 0) + return -EIO; + udelay(10); + reg = readl(®s->canmcr); + } + return 0; +} + +static int freeze_mode_off(struct flexcan_regs __iomem *regs) +{ + u32 reg = readl(®s->canmcr); + int timeout = 10000; + + if (!(reg & CANMCR_FRZACK)) + return 0; + + writel(reg & ~(CANMCR_FRZ | CANMCR_HALT), ®s->canmcr); + while (reg & CANMCR_FRZACK) { + if (--timeout < 0) + return -EIO; + udelay(10); + reg = readl(®s->canmcr); + } + return 0; +} + +static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct can_frame *frame = (struct can_frame *)skb->data; + struct flexcan_priv *priv = netdev_priv(dev); + struct flexcan_regs __iomem *regs = priv->base; + u32 can_id; + u32 ctrl = MB_CNT_CODE(0xc) | (frame->can_dlc << 16); + u32 reg = readl(®s->canctrl); + + reg = readl(®s->cantxfg[TX_BUF_ID].can_ctrl); + + if (reg != MB_CNT_CODE(0x8)) + writel(MB_CNT_CODE(0x08), ®s->cantxfg[TX_BUF_ID].can_ctrl); + + netif_stop_queue(dev); + + if (frame->can_id & CAN_EFF_FLAG) { + can_id = frame->can_id & CAN_EFF_MASK; + ctrl |= MB_CNT_IDE | MB_CNT_SRR; + } else { + can_id = (frame->can_id & CAN_SFF_MASK) << 18; + } + + if (frame->can_id & CAN_RTR_FLAG) + ctrl |= MB_CNT_RTR; + + if (frame->can_dlc > 0) { + u32 data; + data = frame->data[0] << 24; + data |= frame->data[1] << 16; + data |= frame->data[2] << 8; + data |= frame->data[3]; + writel(data, ®s->cantxfg[TX_BUF_ID].data[0]); + } + if (frame->can_dlc > 3) { + u32 data; + data = frame->data[4] << 24; + data |= frame->data[5] << 16; + data |= frame->data[6] << 8; + data |= frame->data[7]; + writel(data, ®s->cantxfg[TX_BUF_ID].data[1]); + } + + writel(can_id, ®s->cantxfg[TX_BUF_ID].can_id); + writel(ctrl, ®s->cantxfg[TX_BUF_ID].can_ctrl); + + kfree_skb(skb); + + return NETDEV_TX_OK; +} + +static void flexcan_rx_frame(struct net_device *ndev, + struct flexcan_mb __iomem *mb) +{ + struct net_device_stats *stats = &ndev->stats; + struct sk_buff *skb; + struct can_frame *frame; + int ctrl, length; + u32 id; + + ctrl = readl(&mb->can_ctrl); + length = (ctrl >> 16) & 0x0f; + if (length > 8) { + stats->rx_dropped++; + return; + } + + skb = dev_alloc_skb(sizeof(struct can_frame)); + if (!skb) { + stats->rx_dropped++; + return; + } + + frame = (struct can_frame *)skb_put(skb, + sizeof(struct can_frame)); + + frame->can_dlc = length; + id = readl(&mb->can_id); + + if (ctrl & MB_CNT_IDE) { + frame->can_id = id & CAN_EFF_MASK; + frame->can_id |= CAN_EFF_FLAG; + } else { + frame->can_id = (id >> 18) & CAN_SFF_MASK; + } + + if (ctrl & MB_CNT_RTR) + frame->can_id |= CAN_RTR_FLAG; + + if (length > 0) { + u32 data = readl(&mb->data[0]); + frame->data[0] = (data >> 24) & 0xff; + frame->data[1] = (data >> 16) & 0xff; + frame->data[2] = (data >> 8) & 0xff; + frame->data[3] = data & 0xff; + } + if (length > 3) { + u32 data = readl(&mb->data[1]); + frame->data[4] = (data >> 24) & 0xff; + frame->data[5] = (data >> 16) & 0xff; + frame->data[6] = (data >> 8) & 0xff; + frame->data[7] = data & 0xff; + } + + stats->rx_packets++; + stats->rx_bytes += frame->can_dlc; + skb->dev = ndev; + skb->protocol = __constant_htons(ETH_P_CAN); + skb->ip_summed = CHECKSUM_UNNECESSARY; + + netif_rx(skb); +} + +static int flexcan_rx_poll(struct napi_struct *napi, int quota) +{ + struct net_device *ndev = napi->dev; + struct flexcan_priv *priv = netdev_priv(ndev); + struct flexcan_regs __iomem *regs = priv->base; + u32 iflags, imask; + int num_pkts = 0; + + if (!netif_running(ndev)) + return 0; + + iflags = readl(®s->iflag1); + + while ((iflags & IFLAG_RX_FIFO_AVAILABLE) && (num_pkts < quota)) { + struct flexcan_mb __iomem *mb = ®s->cantxfg[0]; + + flexcan_rx_frame(ndev, mb); + writel(IFLAG_RX_FIFO_AVAILABLE, ®s->iflag1); + readl(®s->timer); + num_pkts++; + iflags = readl(®s->iflag1); + } + + if (num_pkts < quota) { + napi_complete(napi); + /* Re-enable RX mailbox interrupts */ + imask = readl(®s->imask1); + writel(imask | IFLAG_RX_FIFO_AVAILABLE, ®s->imask1); + } + + return num_pkts; +} + +static void flexcan_error(struct net_device *ndev, u32 stat) +{ + struct can_frame *cf; + struct sk_buff *skb; + struct flexcan_priv *priv = netdev_priv(ndev); + struct net_device_stats *stats = &ndev->stats; + enum can_state state = priv->can.state; + int error_warning = 0, rx_errors = 0, tx_errors = 0; + + skb = dev_alloc_skb(sizeof(struct can_frame)); + if (!skb) + return; + + skb->dev = ndev; + skb->protocol = __constant_htons(ETH_P_CAN); + skb->ip_summed = CHECKSUM_UNNECESSARY; + + cf = (struct can_frame *)skb_put(skb, sizeof(*cf)); + memset(cf, 0, sizeof(*cf)); + + cf->can_id = CAN_ERR_FLAG; + cf->can_dlc = CAN_ERR_DLC; + + if (stat & ERRSTAT_RWRNINT) { + error_warning = 1; + cf->data[1] |= CAN_ERR_CRTL_RX_WARNING; + } + + if (stat & ERRSTAT_TWRNINT) { + error_warning = 1; + cf->data[1] |= CAN_ERR_CRTL_TX_WARNING; + } + + switch ((stat >> 4) & 0x3) { + case 0: + state = CAN_STATE_ERROR_ACTIVE; + break; + case 1: + state = CAN_STATE_ERROR_PASSIVE; + break; + default: + state = CAN_STATE_BUS_OFF; + break; + } + + if (stat & ERRSTAT_BOFFINT) { + cf->can_id |= CAN_ERR_BUSOFF; + state = CAN_STATE_BUS_OFF; + } + + if (stat & ERRSTAT_BIT1ERR) { + rx_errors = 1; + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; + cf->data[2] |= CAN_ERR_PROT_BIT1; + } + + if (stat & ERRSTAT_BIT0ERR) { + rx_errors = 1; + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; + cf->data[2] |= CAN_ERR_PROT_BIT0; + } + + if (stat & ERRSTAT_FRMERR) { + rx_errors = 1; + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; + cf->data[2] |= CAN_ERR_PROT_FORM; + } + + if (stat & ERRSTAT_STFERR) { + rx_errors = 1; + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; + cf->data[2] |= CAN_ERR_PROT_STUFF; + } + + + if (stat & ERRSTAT_ACKERR) { + tx_errors = 1; + cf->can_id |= CAN_ERR_ACK; + } + + if (state == CAN_STATE_BUS_OFF) + can_bus_off(ndev); + if (error_warning) + priv->can.can_stats.error_warning++; + if (rx_errors) + stats->rx_errors++; + if (tx_errors) + stats->tx_errors++; + + priv->can.state = state; + + netif_rx(skb); + + ndev->last_rx = jiffies; + stats->rx_packets++; + stats->rx_bytes += cf->can_dlc; +} + +static irqreturn_t flexcan_isr(int irq, void *dev_id) +{ + struct net_device *ndev = dev_id; + struct net_device_stats *stats = &ndev->stats; + struct flexcan_priv *priv = netdev_priv(ndev); + struct flexcan_regs __iomem *regs = priv->base; + u32 iflags, imask, errstat; + + errstat = readl(®s->errstat); + if (errstat & ERRSTAT_INT) { + flexcan_error(ndev, errstat); + writel(errstat & ERRSTAT_INT, ®s->errstat); + } + + iflags = readl(®s->iflag1); + + if (iflags & IFLAG_RX_FIFO_OVERFLOW) { + writel(IFLAG_RX_FIFO_OVERFLOW, ®s->iflag1); + stats->rx_over_errors++; + stats->rx_errors++; + } + + if (iflags & (1 << TX_BUF_ID)) { + stats->tx_packets++; + writel((1 << TX_BUF_ID), ®s->iflag1); + netif_wake_queue(ndev); + } + + if (iflags & IFLAG_RX_FIFO_AVAILABLE) { + /* disable RX interrupts */ + imask = readl(®s->imask1); + writel(imask & ~IFLAG_RX_FIFO_AVAILABLE, ®s->imask1); + /* Let NAPI poll received packets */ + napi_schedule(&priv->napi); + } + + return IRQ_HANDLED; +} + +static void init_regs(struct flexcan_regs __iomem *regs) +{ + u32 reg; + int i; + + freeze_mode_on(regs); + + /* Enable error and bus off interrupt */ + reg = readl(®s->canctrl); + reg |= CANCTRL_CLKSRC | CANCTRL_ERRMSK | CANCTRL_BOFFMSK | + CANCTRL_BOFFREC | CANCTRL_TWRN_MSK | CANCTRL_TWRN_MSK; + writel(reg, ®s->canctrl); + + /* Set lowest buffer transmitted first */ + reg |= CANCTRL_LBUF; + writel(reg, ®s->canctrl); + + for (i = 0; i < 64; 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(MB_CNT_CODE(0x04), ®s->cantxfg[i].can_ctrl); + } + writel(MB_CNT_CODE(0x08), ®s->cantxfg[TX_BUF_ID].can_ctrl); + + /* acceptance mask/acceptance code (accept everything) */ + writel(0x0, ®s->rxgmask); + writel(0x0, ®s->rx14mask); + writel(0x0, ®s->rx15mask); + + reg = readl(®s->canmcr) & ~0x0f; + reg |= CANMCR_IDAM_C | CANMCR_FEN | CANMCR_MAXMB(TX_BUF_ID); + writel(reg, ®s->canmcr); +} + +static int flexcan_set_bittiming(struct net_device *ndev) +{ + struct flexcan_priv *priv = netdev_priv(ndev); + struct can_bittiming *bt = &priv->can.bittiming; + struct flexcan_regs __iomem *regs = priv->base; + u32 reg; + + clk_enable(priv->clk); + + disable_mode_on(regs); + + reg = readl(®s->canctrl); + reg &= ~(CANCTRL_SAMP | CANCTRL_PRESDIV(0xff) | + CANCTRL_PSEG1(7) | CANCTRL_PSEG2(7) | + CANCTRL_PROPSEG(7)); + reg |= CANCTRL_PRESDIV(bt->brp - 1) | + CANCTRL_PSEG1(bt->phase_seg1 - 1) | + CANCTRL_PSEG2(bt->phase_seg2 - 1) | + CANCTRL_RJW(3) | + CANCTRL_PROPSEG(bt->prop_seg - 1); + if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) + reg |= CANCTRL_SAMP; + writel(reg, ®s->canctrl); + + dev_dbg(&ndev->dev, "flexcan_set_bittiming: canctrl=0x%08x\n", reg); + + clk_disable(priv->clk); + + return 0; +} + +static int flexcan_open(struct net_device *ndev) +{ + int ret; + struct flexcan_priv *priv = netdev_priv(ndev); + struct flexcan_regs __iomem *regs = priv->base; + + clk_enable(priv->clk); + + ret = open_candev(ndev); + if (ret) + return ret; + + disable_mode_off(regs); + init_regs(regs); + + /* Enable flexcan module */ + freeze_mode_off(regs); + + /* Enable interrupts */ + writel(IFLAG_RX_FIFO_OVERFLOW | IFLAG_RX_FIFO_AVAILABLE | + IFLAG_BUF(TX_BUF_ID), + ®s->imask1); + + napi_enable(&priv->napi); + netif_start_queue(ndev); + + ret = request_irq(ndev->irq, flexcan_isr, 0, DRIVER_NAME, ndev); + if (!ret) + return 0; + + close_candev(ndev); + return ret; +} + +static int flexcan_close(struct net_device *ndev) +{ + struct flexcan_priv *priv = netdev_priv(ndev); + struct flexcan_regs __iomem *regs = priv->base; + + netif_stop_queue(ndev); + napi_disable(&priv->napi); + + /* Disable all interrupts */ + writel(0, ®s->imask1); + free_irq(ndev->irq, ndev); + + close_candev(ndev); + + /* Disable module */ + disable_mode_on(regs); + clk_disable(priv->clk); + return 0; +} + +static int flexcan_set_mode(struct net_device *ndev, enum can_mode mode) +{ + struct flexcan_priv *priv = netdev_priv(ndev); + struct flexcan_regs __iomem *regs = priv->base; + u32 reg; + + switch (mode) { + case CAN_MODE_START: + reg = readl(®s->canctrl); + reg &= ~CANCTRL_BOFFREC; + writel(reg, ®s->canctrl); + reg |= CANCTRL_BOFFREC; + writel(reg, ®s->canctrl); + priv->can.state = CAN_STATE_ERROR_ACTIVE; + + if (netif_queue_stopped(ndev)) + netif_wake_queue(ndev); + 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 *ndev) +{ + struct flexcan_priv *priv = netdev_priv(ndev); + struct flexcan_regs __iomem *regs = priv->base; + u32 reg; + + /* Ensure clock is enabled so we can access registers */ + clk_enable(priv->clk); + reg = readl(®s->canmcr); + reg &= ~CANMCR_MDIS; + reg |= CANMCR_FEN; + writel(reg, ®s->canmcr); + init_regs(regs); + udelay(100); + + reg = readl(®s->canmcr); + clk_disable(priv->clk); + + /* Currently we only support newer versions of this core featuring + * a RX FIFO. Older cores found on some Coldfire derivates are not + * yet supported. + */ + if (!(reg & CANMCR_FEN)) { + dev_err(&ndev->dev, "Could not enable RX FIFO, unsupported " + "core"); + return -ENODEV; + } + + ndev->flags |= IFF_ECHO; /* we support local echo in hardware */ + ndev->netdev_ops = &flexcan_netdev_ops; + + return register_candev(ndev); +} + +static void unregister_flexcandev(struct net_device *ndev) +{ + struct flexcan_priv *priv = netdev_priv(ndev); + struct flexcan_regs __iomem *regs = priv->base; + u32 reg; + + clk_enable(priv->clk); + reg = readl(®s->canmcr); + reg |= CANMCR_FRZ | CANMCR_HALT | CANMCR_MDIS; + writel(reg, ®s->canmcr); + clk_disable(priv->clk); + + unregister_candev(ndev); +} + +static int __devinit flexcan_probe(struct platform_device *pdev) +{ + struct resource *mem; + struct net_device *ndev; + struct flexcan_priv *priv; + u32 mem_size; + int ret; + + ndev = alloc_candev(sizeof(struct flexcan_priv), TX_ECHO_SKB_MAX); + if (!ndev) { + dev_err(&pdev->dev, "flexcan: alloc_candev failed.\n"); + return -ENOMEM; + } + + priv = netdev_priv(ndev); + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + + ndev->irq = platform_get_irq(pdev, 0); + if (!mem || !ndev->irq) { + dev_err(&pdev->dev, "flexcan: mem || irq failed.\n"); + ret = -ENODEV; + goto failed_req; + } + + mem_size = resource_size(mem); + + if (!request_mem_region(mem->start, mem_size, DRIVER_NAME)) { + dev_err(&pdev->dev, "flexcan: request_mem_region failed.\n"); + ret = -EBUSY; + goto failed_req; + } + + SET_NETDEV_DEV(ndev, &pdev->dev); + + priv->base = ioremap(mem->start, mem_size); + if (!priv->base) { + dev_err(&pdev->dev, "flexcan: ioremap failed.\n"); + ret = -ENOMEM; + goto failed_map; + } + + priv->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(priv->clk)) { + dev_err(&pdev->dev, "flexcan: clk_get failed.\n"); + ret = PTR_ERR(priv->clk); + goto failed_clock; + } + priv->can.clock.freq = clk_get_rate(priv->clk); + + platform_set_drvdata(pdev, ndev); + + priv->can.do_set_bittiming = flexcan_set_bittiming; + priv->can.bittiming_const = &flexcan_bittiming_const; + priv->can.do_set_mode = flexcan_set_mode; + priv->can.restart_ms = 500; + + netif_napi_add(ndev, &priv->napi, flexcan_rx_poll, + FLEXCAN_DEF_NAPI_WEIGHT); + + ret = register_flexcandev(ndev); + if (ret) { + dev_err(&pdev->dev, "flexcan: register_flexcandev failed.\n"); + goto failed_register; + } + + dev_info(&pdev->dev, "flexcan: probe() succeeded...\n"); + return 0; + +failed_register: + clk_put(priv->clk); +failed_clock: + iounmap(priv->base); +failed_map: + release_mem_region(mem->start, mem_size); +failed_req: + free_candev(ndev); + + return ret; +} + +static int __devexit flexcan_remove(struct platform_device *pdev) +{ + struct net_device *ndev = platform_get_drvdata(pdev); + struct flexcan_priv *priv = netdev_priv(ndev); + struct resource *mem; + + unregister_flexcandev(ndev); + netif_napi_del(&priv->napi); + platform_set_drvdata(pdev, NULL); + iounmap(priv->base); + clk_put(priv->clk); + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + release_mem_region(mem->start, resource_size(mem)); + free_candev(ndev); + + return 0; +} + +static struct platform_driver flexcan_driver = { + .driver = { + .name = DRIVER_NAME, + }, + .probe = flexcan_probe, + .remove = __devexit_p(flexcan_remove), +}; + +static int __init flexcan_init(void) +{ + return platform_driver_register(&flexcan_driver); +} + +static void __exit flexcan_exit(void) +{ + platform_driver_unregister(&flexcan_driver); +} + +module_init(flexcan_init); +module_exit(flexcan_exit); + +MODULE_AUTHOR("Hans J. Koch "); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("SocketCAN driver for FlexCAN based chips"); -- 1.6.3.3