--- /dev/null
+/*
+ * TI HECC (CAN) device driver
+ *
+ * This driver supports TI's HECC (High End CAN Controller module) and the
+ * specs for the same is available at <http://www.ti.com>
+ *
+ * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * 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 as is WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+/*
+ * Your platform definitions should specify module ram offsets and interrupt
+ * number to use as follows:
+ *
+ * static struct ti_hecc_platform_data am3517_evm_hecc_pdata = {
+ * .scc_hecc_offset = 0,
+ * .scc_ram_offset = 0x3000,
+ * .hecc_ram_offset = 0x3000,
+ * .mbx_offset = 0x2000,
+ * .int_line = 0,
+ * .revision = 1,
+ * };
+ *
+ * Please see include/can/platform/ti_hecc.h for description of above fields
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/error.h>
+#include <linux/can/platform/ti_hecc.h>
+
+#define DRV_NAME "ti_hecc"
+#define HECC_MODULE_VERSION "0.7"
+MODULE_VERSION(HECC_MODULE_VERSION);
+#define DRV_DESC "TI High End CAN Controller Driver " HECC_MODULE_VERSION
+
+/* TX / RX Mailbox Configuration */
+#define HECC_MAX_MAILBOXES 32 /* hardware mailboxes - do not change */
+#define MAX_TX_PRIO 0x3F /* hardware value - do not change */
+
+/*
+ * Important Note: TX mailbox configuration
+ * TX mailboxes should be restricted to the number of SKB buffers to avoid
+ * maintaining SKB buffers separately. TX mailboxes should be a power of 2
+ * for the mailbox logic to work. Top mailbox numbers are reserved for RX
+ * and lower mailboxes for TX.
+ *
+ * HECC_MAX_TX_MBOX HECC_MB_TX_SHIFT
+ * 4 (default) 2
+ * 8 3
+ * 16 4
+ */
+#define HECC_MB_TX_SHIFT 2 /* as per table above */
+#define HECC_MAX_TX_MBOX BIT(HECC_MB_TX_SHIFT)
+
+#if (HECC_MAX_TX_MBOX > CAN_ECHO_SKB_MAX)
+#error "HECC: MAX TX mailboxes should be equal or less than CAN_ECHO_SKB_MAX"
+#endif
+
+#define HECC_TX_PRIO_SHIFT (HECC_MB_TX_SHIFT)
+#define HECC_TX_PRIO_MASK (MAX_TX_PRIO << HECC_MB_TX_SHIFT)
+#define HECC_TX_MB_MASK (HECC_MAX_TX_MBOX - 1)
+#define HECC_TX_MASK ((HECC_MAX_TX_MBOX - 1) | HECC_TX_PRIO_MASK)
+#define HECC_TX_MBOX_MASK (~(BIT(HECC_MAX_TX_MBOX) - 1))
+#define HECC_DEF_NAPI_WEIGHT HECC_MAX_RX_MBOX
+
+/*
+ * Important Note: RX mailbox configuration
+ * RX mailboxes are further logically split into two - main and buffer
+ * mailboxes. The goal is to get all packets into main mailboxes as
+ * driven by mailbox number and receive priority (higher to lower) and
+ * buffer mailboxes are used to receive pkts while main mailboxes are being
+ * processed. This ensures in-order packet reception.
+ *
+ * Here are the recommended values for buffer mailbox. Note that RX mailboxes
+ * start after TX mailboxes:
+ *
+ * HECC_MAX_RX_MBOX HECC_RX_BUFFER_MBOX No of buffer mailboxes
+ * 28 12 8
+ * 16 20 4
+ */
+
+#define HECC_MAX_RX_MBOX (HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX)
+#define HECC_RX_BUFFER_MBOX 12 /* as per table above */
+#define HECC_RX_FIRST_MBOX (HECC_MAX_MAILBOXES - 1)
+#define HECC_RX_HIGH_MBOX_MASK (~(BIT(HECC_RX_BUFFER_MBOX) - 1))
+
+/* TI HECC module registers */
+#define HECC_CANME 0x0 /* Mailbox enable */
+#define HECC_CANMD 0x4 /* Mailbox direction */
+#define HECC_CANTRS 0x8 /* Transmit request set */
+#define HECC_CANTRR 0xC /* Transmit request */
+#define HECC_CANTA 0x10 /* Transmission acknowledge */
+#define HECC_CANAA 0x14 /* Abort acknowledge */
+#define HECC_CANRMP 0x18 /* Receive message pending */
+#define HECC_CANRML 0x1C /* Remote message lost */
+#define HECC_CANRFP 0x20 /* Remote frame pending */
+#define HECC_CANGAM 0x24 /* SECC only:Global acceptance mask */
+#define HECC_CANMC 0x28 /* Master control */
+#define HECC_CANBTC 0x2C /* Bit timing configuration */
+#define HECC_CANES 0x30 /* Error and status */
+#define HECC_CANTEC 0x34 /* Transmit error counter */
+#define HECC_CANREC 0x38 /* Receive error counter */
+#define HECC_CANGIF0 0x3C /* Global interrupt flag 0 */
+#define HECC_CANGIM 0x40 /* Global interrupt mask */
+#define HECC_CANGIF1 0x44 /* Global interrupt flag 1 */
+#define HECC_CANMIM 0x48 /* Mailbox interrupt mask */
+#define HECC_CANMIL 0x4C /* Mailbox interrupt level */
+#define HECC_CANOPC 0x50 /* Overwrite protection control */
+#define HECC_CANTIOC 0x54 /* Transmit I/O control */
+#define HECC_CANRIOC 0x58 /* Receive I/O control */
+#define HECC_CANLNT 0x5C /* HECC only: Local network time */
+#define HECC_CANTOC 0x60 /* HECC only: Time-out control */
+#define HECC_CANTOS 0x64 /* HECC only: Time-out status */
+#define HECC_CANTIOCE 0x68 /* SCC only:Enhanced TX I/O control */
+#define HECC_CANRIOCE 0x6C /* SCC only:Enhanced RX I/O control */
+
+/* Mailbox registers */
+#define HECC_CANMID 0x0
+#define HECC_CANMCF 0x4
+#define HECC_CANMDL 0x8
+#define HECC_CANMDH 0xC
+
+#define HECC_SET_REG 0xFFFFFFFF
+#define HECC_CANID_MASK 0x3FF /* 18 bits mask for extended id's */
+#define HECC_CCE_WAIT_COUNT 100 /* Wait for ~1 sec for CCE bit */
+
+#define HECC_CANMC_SCM BIT(13) /* SCC compat mode */
+#define HECC_CANMC_CCR BIT(12) /* Change config request */
+#define HECC_CANMC_PDR BIT(11) /* Local Power down - for sleep mode */
+#define HECC_CANMC_ABO BIT(7) /* Auto Bus On */
+#define HECC_CANMC_STM BIT(6) /* Self test mode - loopback */
+#define HECC_CANMC_SRES BIT(5) /* Software reset */
+
+#define HECC_CANTIOC_EN BIT(3) /* Enable CAN TX I/O pin */
+#define HECC_CANRIOC_EN BIT(3) /* Enable CAN RX I/O pin */
+
+#define HECC_CANMID_IDE BIT(31) /* Extended frame format */
+#define HECC_CANMID_AME BIT(30) /* Acceptance mask enable */
+#define HECC_CANMID_AAM BIT(29) /* Auto answer mode */
+
+#define HECC_CANES_FE BIT(24) /* form error */
+#define HECC_CANES_BE BIT(23) /* bit error */
+#define HECC_CANES_SA1 BIT(22) /* stuck at dominant error */
+#define HECC_CANES_CRCE BIT(21) /* CRC error */
+#define HECC_CANES_SE BIT(20) /* stuff bit error */
+#define HECC_CANES_ACKE BIT(19) /* ack error */
+#define HECC_CANES_BO BIT(18) /* Bus off status */
+#define HECC_CANES_EP BIT(17) /* Error passive status */
+#define HECC_CANES_EW BIT(16) /* Error warning status */
+#define HECC_CANES_SMA BIT(5) /* suspend mode ack */
+#define HECC_CANES_CCE BIT(4) /* Change config enabled */
+#define HECC_CANES_PDA BIT(3) /* Power down mode ack */
+
+#define HECC_CANBTC_SAM BIT(7) /* sample points */
+
+#define HECC_BUS_ERROR (HECC_CANES_FE | HECC_CANES_BE |\
+ HECC_CANES_CRCE | HECC_CANES_SE |\
+ HECC_CANES_ACKE)
+
+#define HECC_CANMCF_RTR BIT(4) /* Remote transmit request */
+
+#define HECC_CANGIF_MAIF BIT(17) /* Message alarm interrupt */
+#define HECC_CANGIF_TCOIF BIT(16) /* Timer counter overflow int */
+#define HECC_CANGIF_GMIF BIT(15) /* Global mailbox interrupt */
+#define HECC_CANGIF_AAIF BIT(14) /* Abort ack interrupt */
+#define HECC_CANGIF_WDIF BIT(13) /* Write denied interrupt */
+#define HECC_CANGIF_WUIF BIT(12) /* Wake up interrupt */
+#define HECC_CANGIF_RMLIF BIT(11) /* Receive message lost interrupt */
+#define HECC_CANGIF_BOIF BIT(10) /* Bus off interrupt */
+#define HECC_CANGIF_EPIF BIT(9) /* Error passive interrupt */
+#define HECC_CANGIF_WLIF BIT(8) /* Warning level interrupt */
+#define HECC_CANGIF_MBOX_MASK 0x1F /* Mailbox number mask */
+#define HECC_CANGIM_I1EN BIT(1) /* Int line 1 enable */
+#define HECC_CANGIM_I0EN BIT(0) /* Int line 0 enable */
+#define HECC_CANGIM_DEF_MASK 0x700 /* only busoff/warning/passive */
+#define HECC_CANGIM_SIL BIT(2) /* system interrupts to int line 1 */
+
+/* CAN Bittiming constants as per HECC specs */
+static struct can_bittiming_const ti_hecc_bittiming_const = {
+ .name = DRV_NAME,
+ .tseg1_min = 1,
+ .tseg1_max = 16,
+ .tseg2_min = 1,
+ .tseg2_max = 8,
+ .sjw_max = 4,
+ .brp_min = 1,
+ .brp_max = 256,
+ .brp_inc = 1,
+};
+
+struct ti_hecc_priv {
+ struct can_priv can; /* MUST be first member/field */
+ struct napi_struct napi;
+ struct net_device *ndev;
+ struct clk *clk;
+ void __iomem *base;
+ u32 scc_ram_offset;
+ u32 hecc_ram_offset;
+ u32 mbx_offset;
+ u32 int_line;
+ spinlock_t mbx_lock; /* CANME register needs protection */
+ u32 tx_head;
+ u32 tx_tail;
+ u32 rx_next;
+};
+
+static inline int get_tx_head_mb(struct ti_hecc_priv *priv)
+{
+ return priv->tx_head & HECC_TX_MB_MASK;
+}
+
+static inline int get_tx_tail_mb(struct ti_hecc_priv *priv)
+{
+ return priv->tx_tail & HECC_TX_MB_MASK;
+}
+
+static inline int get_tx_head_prio(struct ti_hecc_priv *priv)
+{
+ return (priv->tx_head >> HECC_TX_PRIO_SHIFT) & MAX_TX_PRIO;
+}
+
+static inline void hecc_write_lam(struct ti_hecc_priv *priv, u32 mbxno, u32 val)
+{
+ __raw_writel(val, priv->base + priv->hecc_ram_offset + mbxno * 4);
+}
+
+static inline void hecc_write_mbx(struct ti_hecc_priv *priv, u32 mbxno,
+ u32 reg, u32 val)
+{
+ __raw_writel(val, priv->base + priv->mbx_offset + mbxno * 0x10 +
+ reg);
+}
+
+static inline u32 hecc_read_mbx(struct ti_hecc_priv *priv, u32 mbxno, u32 reg)
+{
+ return __raw_readl(priv->base + priv->mbx_offset + mbxno * 0x10 +
+ reg);
+}
+
+static inline void hecc_write(struct ti_hecc_priv *priv, u32 reg, u32 val)
+{
+ __raw_writel(val, priv->base + reg);
+}
+
+static inline u32 hecc_read(struct ti_hecc_priv *priv, int reg)
+{
+ return __raw_readl(priv->base + reg);
+}
+
+static inline void hecc_set_bit(struct ti_hecc_priv *priv, int reg,
+ u32 bit_mask)
+{
+ hecc_write(priv, reg, hecc_read(priv, reg) | bit_mask);
+}
+
+static inline void hecc_clear_bit(struct ti_hecc_priv *priv, int reg,
+ u32 bit_mask)
+{
+ hecc_write(priv, reg, hecc_read(priv, reg) & ~bit_mask);
+}
+
+static inline u32 hecc_get_bit(struct ti_hecc_priv *priv, int reg, u32 bit_mask)
+{
+ return (hecc_read(priv, reg) & bit_mask) ? 1 : 0;
+}
+
+static int ti_hecc_get_state(const struct net_device *ndev,
+ enum can_state *state)
+{
+ struct ti_hecc_priv *priv = netdev_priv(ndev);
+
+ *state = priv->can.state;
+ return 0;
+}
+
+static int ti_hecc_set_btc(struct ti_hecc_priv *priv)
+{
+ struct can_bittiming *bit_timing = &priv->can.bittiming;
+ u32 can_btc;
+
+ can_btc = (bit_timing->phase_seg2 - 1) & 0x7;
+ can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1)
+ & 0xF) << 3;
+ if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) {
+ if (bit_timing->brp > 4)
+ can_btc |= HECC_CANBTC_SAM;
+ else
+ dev_warn(priv->ndev->dev.parent, "WARN: Triple" \
+ "sampling not set due to h/w limitations");
+ }
+ can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8;
+ can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16;
+
+ /* ERM being set to 0 by default meaning resync at falling edge */
+
+ hecc_write(priv, HECC_CANBTC, can_btc);
+ dev_info(priv->ndev->dev.parent, "setting CANBTC=%#x\n", can_btc);
+
+ return 0;
+}
+
+static void ti_hecc_reset(struct net_device *ndev)
+{
+ u32 cnt;
+ struct ti_hecc_priv *priv = netdev_priv(ndev);
+
+ dev_dbg(ndev->dev.parent, "resetting hecc ...\n");
+ hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES);
+
+ /* Set change control request and wait till enabled */
+ hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
+
+ /*
+ * INFO: It has been observed that at times CCE bit may not be
+ * set and hw seems to be ok even if this bit is not set so
+ * timing out with a timing of 1ms to respect the specs
+ */
+ cnt = HECC_CCE_WAIT_COUNT;
+ while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
+ --cnt;
+ udelay(10);
+ }
+
+ /*
+ * Note: On HECC, BTC can be programmed only in initialization mode, so
+ * it is expected that the can bittiming parameters are set via ip
+ * utility before the device is opened
+ */
+ ti_hecc_set_btc(priv);
+
+ /* Clear CCR (and CANMC register) and wait for CCE = 0 enable */
+ hecc_write(priv, HECC_CANMC, 0);
+
+ /*
+ * INFO: CAN net stack handles bus off and hence disabling auto-bus-on
+ * hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO);
+ */
+
+ /*
+ * INFO: It has been observed that at times CCE bit may not be
+ * set and hw seems to be ok even if this bit is not set so
+ */
+ cnt = HECC_CCE_WAIT_COUNT;
+ while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
+ --cnt;
+ udelay(10);
+ }
+
+ /* Enable TX and RX I/O Control pins */
+ hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN);
+ hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN);
+
+ /* Clear registers for clean operation */
+ hecc_write(priv, HECC_CANTA, HECC_SET_REG);
+ hecc_write(priv, HECC_CANRMP, HECC_SET_REG);
+ hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
+ hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
+ hecc_write(priv, HECC_CANME, 0);
+ hecc_write(priv, HECC_CANMD, 0);
+
+ /* SCC compat mode NOT supported (and not needed too) */
+ hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM);
+}
+
+static void ti_hecc_start(struct net_device *ndev)
+{
+ struct ti_hecc_priv *priv = netdev_priv(ndev);
+ u32 cnt, mbxno, mbx_mask;
+
+ /* put HECC in initialization mode and set btc */
+ ti_hecc_reset(ndev);
+
+ priv->tx_head = priv->tx_tail = HECC_TX_MASK;
+ priv->rx_next = HECC_RX_FIRST_MBOX;
+
+ /* Enable local and global acceptance mask registers */
+ hecc_write(priv, HECC_CANGAM, HECC_SET_REG);
+
+ /* Prepare configured mailboxes to receive messages */
+ for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) {
+ mbxno = HECC_MAX_MAILBOXES - 1 - cnt;
+ mbx_mask = BIT(mbxno);
+ hecc_clear_bit(priv, HECC_CANME, mbx_mask);
+ hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME);
+ hecc_write_lam(priv, mbxno, HECC_SET_REG);
+ hecc_set_bit(priv, HECC_CANMD, mbx_mask);
+ hecc_set_bit(priv, HECC_CANME, mbx_mask);
+ hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
+ }
+
+ /* Prevent message over-write & Enable interrupts */
+ hecc_write(priv, HECC_CANOPC, HECC_SET_REG);
+ if (priv->int_line) {
+ hecc_write(priv, HECC_CANMIL, HECC_SET_REG);
+ hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK |
+ HECC_CANGIM_I1EN | HECC_CANGIM_SIL);
+ } else {
+ hecc_write(priv, HECC_CANMIL, 0);
+ hecc_write(priv, HECC_CANGIM,
+ HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN);
+ }
+ priv->can.state = CAN_STATE_ERROR_ACTIVE;
+}
+
+static void ti_hecc_stop(struct net_device *ndev)
+{
+ struct ti_hecc_priv *priv = netdev_priv(ndev);
+
+ /* Disable interrupts and disable mailboxes */
+ hecc_write(priv, HECC_CANGIM, 0);
+ hecc_write(priv, HECC_CANMIM, 0);
+ hecc_write(priv, HECC_CANME, 0);
+ priv->can.state = CAN_STATE_STOPPED;
+}
+
+static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode)
+{
+ int ret = 0;
+
+ switch (mode) {
+ case CAN_MODE_START:
+ ti_hecc_start(ndev);
+ netif_wake_queue(ndev);
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ break;
+ }
+
+ return ret;
+}
+
+/*
+ * ti_hecc_xmit: HECC Transmit
+ *
+ * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the
+ * priority of the mailbox for tranmission is dependent upon priority setting
+ * field in mailbox registers. The mailbox with highest value in priority field
+ * is transmitted first. Only when two mailboxes have the same value in
+ * priority field the highest numbered mailbox is transmitted first.
+ *
+ * To utilize the HECC priority feature as described above we start with the
+ * highest numbered mailbox with highest priority level and move on to the next
+ * mailbox with the same priority level and so on. Once we loop through all the
+ * transmit mailboxes we choose the next priority level (lower) and so on
+ * until we reach the lowest priority level on the lowest numbered mailbox
+ * when we stop transmission until all mailboxes are transmitted and then
+ * restart at highest numbered mailbox with highest priority.
+ *
+ * Two counters (head and tail) are used to track the next mailbox to transmit
+ * and to track the echo buffer for already transmitted mailbox. The queue
+ * is stopped when all the mailboxes are busy or when there is a priority
+ * value roll-over happens.
+ */
+static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+ struct ti_hecc_priv *priv = netdev_priv(ndev);
+ struct can_frame *cf = (struct can_frame *)skb->data;
+ u32 mbxno, mbx_mask, data;
+ unsigned long flags;
+
+ mbxno = get_tx_head_mb(priv);
+ mbx_mask = BIT(mbxno);
+ spin_lock_irqsave(&priv->mbx_lock, flags);
+ if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) {
+ spin_unlock_irqrestore(&priv->mbx_lock, flags);
+ netif_stop_queue(ndev);
+ dev_err(priv->ndev->dev.parent,
+ "BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n",
+ priv->tx_head, priv->tx_tail);
+ return NETDEV_TX_BUSY;
+ }
+ spin_unlock_irqrestore(&priv->mbx_lock, flags);
+
+ /* Prepare mailbox for transmission */
+ data = min_t(u8, cf->can_dlc, 8);
+ if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */
+ data |= HECC_CANMCF_RTR;
+ data |= get_tx_head_prio(priv) << 8;
+ hecc_write_mbx(priv, mbxno, HECC_CANMCF, data);
+
+ if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
+ data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE;
+ else /* Standard frame format */
+ data = (cf->can_id & CAN_SFF_MASK) << 18;
+ hecc_write_mbx(priv, mbxno, HECC_CANMID, data);
+ hecc_write_mbx(priv, mbxno, HECC_CANMDL,
+ be32_to_cpu(*(u32 *)(cf->data)));
+ if (cf->can_dlc > 4)
+ hecc_write_mbx(priv, mbxno, HECC_CANMDH,
+ be32_to_cpu(*(u32 *)(cf->data + 4)));
+ else
+ *(u32 *)(cf->data + 4) = 0;
+ can_put_echo_skb(skb, ndev, mbxno);
+
+ spin_lock_irqsave(&priv->mbx_lock, flags);
+ --priv->tx_head;
+ if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) ||
+ (priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) {
+ netif_stop_queue(ndev);
+ }
+ hecc_set_bit(priv, HECC_CANME, mbx_mask);
+ spin_unlock_irqrestore(&priv->mbx_lock, flags);
+
+ hecc_clear_bit(priv, HECC_CANMD, mbx_mask);
+ hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
+ hecc_write(priv, HECC_CANTRS, mbx_mask);
+
+ return NETDEV_TX_OK;
+}
+
+static int ti_hecc_rx_pkt(struct ti_hecc_priv *priv, int mbxno)
+{
+ struct net_device_stats *stats = &priv->ndev->stats;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+ u32 data, mbx_mask;
+ unsigned long flags;
+
+ skb = netdev_alloc_skb(priv->ndev, sizeof(struct can_frame));
+ if (!skb) {
+ if (printk_ratelimit())
+ dev_err(priv->ndev->dev.parent,
+ "ti_hecc_rx_pkt: netdev_alloc_skb() failed\n");
+ return -ENOMEM;
+ }
+ skb->protocol = __constant_htons(ETH_P_CAN);
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ mbx_mask = BIT(mbxno);
+ cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
+ data = hecc_read_mbx(priv, mbxno, HECC_CANMID);
+ if (data & HECC_CANMID_IDE)
+ cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
+ else
+ cf->can_id = (data >> 18) & CAN_SFF_MASK;
+ data = hecc_read_mbx(priv, mbxno, HECC_CANMCF);
+ if (data & HECC_CANMCF_RTR)
+ cf->can_id |= CAN_RTR_FLAG;
+ cf->can_dlc = data & 0xF;
+ data = hecc_read_mbx(priv, mbxno, HECC_CANMDL);
+ *(u32 *)(cf->data) = cpu_to_be32(data);
+ if (cf->can_dlc > 4) {
+ data = hecc_read_mbx(priv, mbxno, HECC_CANMDH);
+ *(u32 *)(cf->data + 4) = cpu_to_be32(data);
+ } else {
+ *(u32 *)(cf->data + 4) = 0;
+ }
+ spin_lock_irqsave(&priv->mbx_lock, flags);
+ hecc_clear_bit(priv, HECC_CANME, mbx_mask);
+ hecc_write(priv, HECC_CANRMP, mbx_mask);
+ /* enable mailbox only if it is part of rx buffer mailboxes */
+ if (priv->rx_next < HECC_RX_BUFFER_MBOX)
+ hecc_set_bit(priv, HECC_CANME, mbx_mask);
+ spin_unlock_irqrestore(&priv->mbx_lock, flags);
+
+ stats->rx_bytes += cf->can_dlc;
+ netif_receive_skb(skb);
+ stats->rx_packets++;
+
+ return 0;
+}
+
+/*
+ * ti_hecc_rx_poll - HECC receive pkts
+ *
+ * The receive mailboxes start from highest numbered mailbox till last xmit
+ * mailbox. On CAN frame reception the hardware places the data into highest
+ * numbered mailbox that matches the CAN ID filter. Since all receive mailboxes
+ * have same filtering (ALL CAN frames) packets will arrive in the highest
+ * available RX mailbox and we need to ensure in-order packet reception.
+ *
+ * To ensure the packets are received in the right order we logically divide
+ * the RX mailboxes into main and buffer mailboxes. Packets are received as per
+ * mailbox priotity (higher to lower) in the main bank and once it is full we
+ * disable further reception into main mailboxes. While the main mailboxes are
+ * processed in NAPI, further packets are received in buffer mailboxes.
+ *
+ * We maintain a RX next mailbox counter to process packets and once all main
+ * mailboxe packets are passed to the upper stack we enable all of them but
+ * continue to process packets received in buffer mailboxes. With each packet
+ * received from buffer mailbox we enable it immediately so as to handle the
+ * overflow from higher mailboxes.
+ */
+static int ti_hecc_rx_poll(struct napi_struct *napi, int quota)
+{
+ struct net_device *ndev = napi->dev;
+ struct ti_hecc_priv *priv = netdev_priv(ndev);
+ u32 num_pkts = 0;
+ u32 mbx_mask;
+ unsigned long pending_pkts, flags;
+
+ if (!netif_running(ndev))
+ return 0;
+
+ while ((pending_pkts = hecc_read(priv, HECC_CANRMP)) &&
+ num_pkts < quota) {
+ mbx_mask = BIT(priv->rx_next); /* next rx mailbox to process */
+ if (mbx_mask & pending_pkts) {
+ if (ti_hecc_rx_pkt(priv, priv->rx_next) < 0)
+ return num_pkts;
+ ++num_pkts;
+ } else if (priv->rx_next > HECC_RX_BUFFER_MBOX) {
+ break; /* pkt not received yet */
+ }
+ --priv->rx_next;
+ if (priv->rx_next == HECC_RX_BUFFER_MBOX) {
+ /* enable high bank mailboxes */
+ spin_lock_irqsave(&priv->mbx_lock, flags);
+ mbx_mask = hecc_read(priv, HECC_CANME);
+ mbx_mask |= HECC_RX_HIGH_MBOX_MASK;
+ hecc_write(priv, HECC_CANME, mbx_mask);
+ spin_unlock_irqrestore(&priv->mbx_lock, flags);
+ } else if (priv->rx_next == HECC_MAX_TX_MBOX - 1) {
+ priv->rx_next = HECC_RX_FIRST_MBOX;
+ break;
+ }
+ }
+
+ /* Enable packet interrupt if all pkts are handled */
+ if (hecc_read(priv, HECC_CANRMP) == 0) {
+ napi_complete(napi);
+ /* Re-enable RX mailbox interrupts */
+ mbx_mask = hecc_read(priv, HECC_CANMIM);
+ mbx_mask |= HECC_TX_MBOX_MASK;
+ hecc_write(priv, HECC_CANMIM, mbx_mask);
+ }
+
+ return num_pkts;
+}
+
+static int ti_hecc_error(struct net_device *ndev, int int_status,
+ int err_status)
+{
+ struct ti_hecc_priv *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &ndev->stats;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+
+ /* propogate the error condition to the can stack */
+ skb = netdev_alloc_skb(ndev, sizeof(struct can_frame));
+ if (!skb) {
+ if (printk_ratelimit())
+ dev_err(priv->ndev->dev.parent,
+ "ti_hecc_error: netdev_alloc_skb() failed\n");
+ return -ENOMEM;
+ }
+ skb->protocol = __constant_htons(ETH_P_CAN);
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
+ memset(cf, 0, sizeof(struct can_frame));
+ cf->can_id = CAN_ERR_FLAG;
+ cf->can_dlc = CAN_ERR_DLC;
+
+ if (int_status & HECC_CANGIF_WLIF) { /* warning level int */
+ if ((int_status & HECC_CANGIF_BOIF) == 0) {
+ priv->can.state = CAN_STATE_ERROR_WARNING;
+ ++priv->can.can_stats.error_warning;
+ cf->can_id |= CAN_ERR_CRTL;
+ if (hecc_read(priv, HECC_CANTEC) > 96)
+ cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
+ if (hecc_read(priv, HECC_CANREC) > 96)
+ cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
+ }
+ hecc_set_bit(priv, HECC_CANES, HECC_CANES_EW);
+ dev_dbg(priv->ndev->dev.parent, "Error Warning interrupt\n");
+ hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
+ }
+
+ if (int_status & HECC_CANGIF_EPIF) { /* error passive int */
+ if ((int_status & HECC_CANGIF_BOIF) == 0) {
+ priv->can.state = CAN_STATE_ERROR_PASSIVE;
+ ++priv->can.can_stats.error_passive;
+ cf->can_id |= CAN_ERR_CRTL;
+ if (hecc_read(priv, HECC_CANTEC) > 127)
+ cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
+ if (hecc_read(priv, HECC_CANREC) > 127)
+ cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
+ }
+ hecc_set_bit(priv, HECC_CANES, HECC_CANES_EP);
+ dev_dbg(priv->ndev->dev.parent, "Error passive interrupt\n");
+ hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
+ }
+
+ /*
+ * Need to check busoff condition in error status register too to
+ * ensure warning interrupts don't hog the system
+ */
+ if ((int_status & HECC_CANGIF_BOIF) || (err_status & HECC_CANES_BO)) {
+ priv->can.state = CAN_STATE_BUS_OFF;
+ cf->can_id |= CAN_ERR_BUSOFF;
+ hecc_set_bit(priv, HECC_CANES, HECC_CANES_BO);
+ hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
+ /* Disable all interrupts in bus-off to avoid int hog */
+ hecc_write(priv, HECC_CANGIM, 0);
+ can_bus_off(ndev);
+ }
+
+ if (err_status & HECC_BUS_ERROR) {
+ ++priv->can.can_stats.bus_error;
+ cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
+ cf->data[2] |= CAN_ERR_PROT_UNSPEC;
+ if (err_status & HECC_CANES_FE) {
+ hecc_set_bit(priv, HECC_CANES, HECC_CANES_FE);
+ cf->data[2] |= CAN_ERR_PROT_FORM;
+ }
+ if (err_status & HECC_CANES_BE) {
+ hecc_set_bit(priv, HECC_CANES, HECC_CANES_BE);
+ cf->data[2] |= CAN_ERR_PROT_BIT;
+ }
+ if (err_status & HECC_CANES_SE) {
+ hecc_set_bit(priv, HECC_CANES, HECC_CANES_SE);
+ cf->data[2] |= CAN_ERR_PROT_STUFF;
+ }
+ if (err_status & HECC_CANES_CRCE) {
+ hecc_set_bit(priv, HECC_CANES, HECC_CANES_CRCE);
+ cf->data[2] |= CAN_ERR_PROT_LOC_CRC_SEQ |
+ CAN_ERR_PROT_LOC_CRC_DEL;
+ }
+ if (err_status & HECC_CANES_ACKE) {
+ hecc_set_bit(priv, HECC_CANES, HECC_CANES_ACKE);
+ cf->data[2] |= CAN_ERR_PROT_LOC_ACK |
+ CAN_ERR_PROT_LOC_ACK_DEL;
+ }
+ }
+
+ netif_receive_skb(skb);
+ stats->rx_packets++;
+ stats->rx_bytes += cf->can_dlc;
+ return 0;
+}
+
+static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
+{
+ struct net_device *ndev = (struct net_device *)dev_id;
+ struct ti_hecc_priv *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &ndev->stats;
+ u32 mbxno, mbx_mask, int_status, err_status;
+ unsigned long ack, flags;
+
+ int_status = hecc_read(priv,
+ (priv->int_line) ? HECC_CANGIF1 : HECC_CANGIF0);
+
+ if (!int_status)
+ return IRQ_NONE;
+
+ err_status = hecc_read(priv, HECC_CANES);
+ if (err_status & (HECC_BUS_ERROR | HECC_CANES_BO |
+ HECC_CANES_EP | HECC_CANES_EW))
+ ti_hecc_error(ndev, int_status, err_status);
+
+ if (int_status & HECC_CANGIF_GMIF) {
+ while (priv->tx_tail - priv->tx_head > 0) {
+ mbxno = get_tx_tail_mb(priv);
+ mbx_mask = BIT(mbxno);
+ if (!(mbx_mask & hecc_read(priv, HECC_CANTA)))
+ break;
+ hecc_clear_bit(priv, HECC_CANMIM, mbx_mask);
+ hecc_write(priv, HECC_CANTA, mbx_mask);
+ spin_lock_irqsave(&priv->mbx_lock, flags);
+ hecc_clear_bit(priv, HECC_CANME, mbx_mask);
+ spin_unlock_irqrestore(&priv->mbx_lock, flags);
+ stats->tx_bytes += hecc_read_mbx(priv, mbxno,
+ HECC_CANMCF) & 0xF;
+ stats->tx_packets++;
+ can_get_echo_skb(ndev, mbxno);
+ --priv->tx_tail;
+ }
+
+ /* restart queue if wrap-up or if queue stalled on last pkt */
+ if (((priv->tx_head == priv->tx_tail) &&
+ ((priv->tx_head & HECC_TX_MASK) != HECC_TX_MASK)) ||
+ (((priv->tx_tail & HECC_TX_MASK) == HECC_TX_MASK) &&
+ ((priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK)))
+ netif_wake_queue(ndev);
+
+ /* Disable RX mailbox interrupts and let NAPI reenable them */
+ if (hecc_read(priv, HECC_CANRMP)) {
+ ack = hecc_read(priv, HECC_CANMIM);
+ ack &= BIT(HECC_MAX_TX_MBOX) - 1;
+ hecc_write(priv, HECC_CANMIM, ack);
+ napi_schedule(&priv->napi);
+ }
+ }
+
+ /* clear all interrupt conditions - read back to avoid spurious ints */
+ if (priv->int_line) {
+ hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
+ int_status = hecc_read(priv, HECC_CANGIF1);
+ } else {
+ hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
+ int_status = hecc_read(priv, HECC_CANGIF0);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int ti_hecc_open(struct net_device *ndev)
+{
+ struct ti_hecc_priv *priv = netdev_priv(ndev);
+ int err;
+
+ err = request_irq(ndev->irq, ti_hecc_interrupt, IRQF_SHARED,
+ ndev->name, ndev);
+ if (err) {
+ dev_err(ndev->dev.parent, "error requesting interrupt\n");
+ return err;
+ }
+
+ /* Open common can device */
+ err = open_candev(ndev);
+ if (err) {
+ dev_err(ndev->dev.parent, "open_candev() failed %d\n", err);
+ free_irq(ndev->irq, ndev);
+ return err;
+ }
+
+ clk_enable(priv->clk);
+ ti_hecc_start(ndev);
+ napi_enable(&priv->napi);
+ netif_start_queue(ndev);
+
+ return 0;
+}
+
+static int ti_hecc_close(struct net_device *ndev)
+{
+ struct ti_hecc_priv *priv = netdev_priv(ndev);
+
+ netif_stop_queue(ndev);
+ napi_disable(&priv->napi);
+ ti_hecc_stop(ndev);
+ free_irq(ndev->irq, ndev);
+ clk_disable(priv->clk);
+ close_candev(ndev);
+
+ return 0;
+}
+
+static const struct net_device_ops ti_hecc_netdev_ops = {
+ .ndo_open = ti_hecc_open,
+ .ndo_stop = ti_hecc_close,
+ .ndo_start_xmit = ti_hecc_xmit,
+};
+
+static int ti_hecc_probe(struct platform_device *pdev)
+{
+ struct net_device *ndev = (struct net_device *)0;
+ struct ti_hecc_priv *priv;
+ struct ti_hecc_platform_data *pdata;
+ struct resource *mem, *irq;
+ void __iomem *addr;
+ int err = -ENODEV;
+
+ pdata = pdev->dev.platform_data;
+ if (!pdata) {
+ dev_err(&pdev->dev, "No platform data\n");
+ goto probe_exit;
+ }
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!mem) {
+ dev_err(&pdev->dev, "No mem resources\n");
+ goto probe_exit;
+ }
+ irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!irq) {
+ dev_err(&pdev->dev, "No irq resource\n");
+ goto probe_exit;
+ }
+ if (!request_mem_region(mem->start, resource_size(mem), pdev->name)) {
+ dev_err(&pdev->dev, "HECC region already claimed\n");
+ err = -EBUSY;
+ goto probe_exit;
+ }
+ addr = ioremap(mem->start, resource_size(mem));
+ if (!addr) {
+ dev_err(&pdev->dev, "ioremap failed\n");
+ err = -ENOMEM;
+ goto probe_exit_free_region;
+ }
+
+ ndev = alloc_candev(sizeof(struct ti_hecc_priv));
+ if (!ndev) {
+ dev_err(&pdev->dev, "alloc_candev failed\n");
+ err = -ENOMEM;
+ goto probe_exit_iounmap;
+ }
+
+ priv = netdev_priv(ndev);
+ priv->ndev = ndev;
+ priv->base = addr;
+ priv->scc_ram_offset = pdata->scc_ram_offset;
+ priv->hecc_ram_offset = pdata->hecc_ram_offset;
+ priv->mbx_offset = pdata->mbx_offset;
+ priv->int_line = pdata->int_line;
+
+ priv->can.bittiming_const = &ti_hecc_bittiming_const;
+ priv->can.do_set_mode = ti_hecc_do_set_mode;
+ priv->can.do_get_state = ti_hecc_get_state;
+
+ ndev->irq = irq->start;
+ ndev->flags |= IFF_ECHO;
+ platform_set_drvdata(pdev, ndev);
+ SET_NETDEV_DEV(ndev, &pdev->dev);
+ ndev->netdev_ops = &ti_hecc_netdev_ops;
+
+ priv->clk = clk_get(&pdev->dev, "hecc_ck");
+ if (IS_ERR(priv->clk)) {
+ dev_err(&pdev->dev, "No clock available\n");
+ err = PTR_ERR(priv->clk);
+ priv->clk = NULL;
+ goto probe_exit_candev;
+ }
+ priv->can.clock.freq = clk_get_rate(priv->clk);
+ netif_napi_add(ndev, &priv->napi, ti_hecc_rx_poll,
+ HECC_DEF_NAPI_WEIGHT);
+
+ err = register_candev(ndev);
+ if (err) {
+ dev_err(&pdev->dev, "register_candev() failed\n");
+ goto probe_exit_clk;
+ }
+ dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n",
+ priv->base, (u32) ndev->irq);
+
+ return 0;
+
+probe_exit_clk:
+ clk_put(priv->clk);
+probe_exit_candev:
+ free_candev(ndev);
+probe_exit_iounmap:
+ iounmap(addr);
+probe_exit_free_region:
+ release_mem_region(mem->start, resource_size(mem));
+probe_exit:
+ return err;
+}
+
+static int __devexit ti_hecc_remove(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct net_device *ndev = platform_get_drvdata(pdev);
+ struct ti_hecc_priv *priv = netdev_priv(ndev);
+
+ clk_put(priv->clk);
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ iounmap(priv->base);
+ release_mem_region(res->start, resource_size(res));
+ unregister_candev(ndev);
+ free_candev(ndev);
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+/* TI HECC netdevice driver: platform driver structure */
+static struct platform_driver ti_hecc_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = ti_hecc_probe,
+ .remove = __devexit_p(ti_hecc_remove),
+};
+
+static int __init ti_hecc_init_driver(void)
+{
+ printk(KERN_INFO DRV_DESC "\n");
+ return platform_driver_register(&ti_hecc_driver);
+}
+module_init(ti_hecc_init_driver);
+
+static void __exit ti_hecc_exit_driver(void)
+{
+ printk(KERN_INFO DRV_DESC " unloaded\n");
+ platform_driver_unregister(&ti_hecc_driver);
+}
+module_exit(ti_hecc_exit_driver);
+
+MODULE_AUTHOR("Anant Gole <anantgole@ti.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION(DRV_DESC);
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