--- /dev/null
+/*
+ * 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");
projects / kernel / kernel-generic.git / commitdiff