/* * sun4i_can.c - CAN bus controller driver for Allwinner SUN4I&SUN7I based SoCs * * Copyright (C) 2013 Peter Chen * Copyright (C) 2015 Gerhard Bertelsmann * All rights reserved. * * Parts of this software are based on (derived from) the SJA1000 code by: * Copyright (C) 2014 Oliver Hartkopp * Copyright (C) 2007 Wolfgang Grandegger * Copyright (C) 2002-2007 Volkswagen Group Electronic Research * Copyright (C) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33, * 38106 Braunschweig, GERMANY * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of Volkswagen nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * Alternatively, provided that this notice is retained in full, this * software may be distributed under the terms of the GNU General * Public License ("GPL") version 2, in which case the provisions of the * GPL apply INSTEAD OF those given above. * * The provided data structures and external interfaces from this code * are not restricted to be used by modules with a GPL compatible license. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH * DAMAGE. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DRV_NAME "sun4i_can" /* Registers address (physical base address 0x01C2BC00) */ #define SUN4I_REG_MSEL_ADDR 0x0000 /* CAN Mode Select */ #define SUN4I_REG_CMD_ADDR 0x0004 /* CAN Command */ #define SUN4I_REG_STA_ADDR 0x0008 /* CAN Status */ #define SUN4I_REG_INT_ADDR 0x000c /* CAN Interrupt Flag */ #define SUN4I_REG_INTEN_ADDR 0x0010 /* CAN Interrupt Enable */ #define SUN4I_REG_BTIME_ADDR 0x0014 /* CAN Bus Timing 0 */ #define SUN4I_REG_TEWL_ADDR 0x0018 /* CAN Tx Error Warning Limit */ #define SUN4I_REG_ERRC_ADDR 0x001c /* CAN Error Counter */ #define SUN4I_REG_RMCNT_ADDR 0x0020 /* CAN Receive Message Counter */ #define SUN4I_REG_RBUFSA_ADDR 0x0024 /* CAN Receive Buffer Start Address */ #define SUN4I_REG_BUF0_ADDR 0x0040 /* CAN Tx/Rx Buffer 0 */ #define SUN4I_REG_BUF1_ADDR 0x0044 /* CAN Tx/Rx Buffer 1 */ #define SUN4I_REG_BUF2_ADDR 0x0048 /* CAN Tx/Rx Buffer 2 */ #define SUN4I_REG_BUF3_ADDR 0x004c /* CAN Tx/Rx Buffer 3 */ #define SUN4I_REG_BUF4_ADDR 0x0050 /* CAN Tx/Rx Buffer 4 */ #define SUN4I_REG_BUF5_ADDR 0x0054 /* CAN Tx/Rx Buffer 5 */ #define SUN4I_REG_BUF6_ADDR 0x0058 /* CAN Tx/Rx Buffer 6 */ #define SUN4I_REG_BUF7_ADDR 0x005c /* CAN Tx/Rx Buffer 7 */ #define SUN4I_REG_BUF8_ADDR 0x0060 /* CAN Tx/Rx Buffer 8 */ #define SUN4I_REG_BUF9_ADDR 0x0064 /* CAN Tx/Rx Buffer 9 */ #define SUN4I_REG_BUF10_ADDR 0x0068 /* CAN Tx/Rx Buffer 10 */ #define SUN4I_REG_BUF11_ADDR 0x006c /* CAN Tx/Rx Buffer 11 */ #define SUN4I_REG_BUF12_ADDR 0x0070 /* CAN Tx/Rx Buffer 12 */ #define SUN4I_REG_ACPC_ADDR 0x0040 /* CAN Acceptance Code 0 */ #define SUN4I_REG_ACPM_ADDR 0x0044 /* CAN Acceptance Mask 0 */ #define SUN4I_REG_RBUF_RBACK_START_ADDR 0x0180 /* CAN transmit buffer start */ #define SUN4I_REG_RBUF_RBACK_END_ADDR 0x01b0 /* CAN transmit buffer end */ /* Controller Register Description */ /* mode select register (r/w) * offset:0x0000 default:0x0000_0001 */ #define SUN4I_MSEL_SLEEP_MODE (0x01 << 4) /* write in reset mode */ #define SUN4I_MSEL_WAKE_UP (0x00 << 4) #define SUN4I_MSEL_SINGLE_FILTER (0x01 << 3) /* write in reset mode */ #define SUN4I_MSEL_DUAL_FILTERS (0x00 << 3) #define SUN4I_MSEL_LOOPBACK_MODE BIT(2) #define SUN4I_MSEL_LISTEN_ONLY_MODE BIT(1) #define SUN4I_MSEL_RESET_MODE BIT(0) /* command register (w) * offset:0x0004 default:0x0000_0000 */ #define SUN4I_CMD_BUS_OFF_REQ BIT(5) #define SUN4I_CMD_SELF_RCV_REQ BIT(4) #define SUN4I_CMD_CLEAR_OR_FLAG BIT(3) #define SUN4I_CMD_RELEASE_RBUF BIT(2) #define SUN4I_CMD_ABORT_REQ BIT(1) #define SUN4I_CMD_TRANS_REQ BIT(0) /* status register (r) * offset:0x0008 default:0x0000_003c */ #define SUN4I_STA_BIT_ERR (0x00 << 22) #define SUN4I_STA_FORM_ERR (0x01 << 22) #define SUN4I_STA_STUFF_ERR (0x02 << 22) #define SUN4I_STA_OTHER_ERR (0x03 << 22) #define SUN4I_STA_MASK_ERR (0x03 << 22) #define SUN4I_STA_ERR_DIR BIT(21) #define SUN4I_STA_ERR_SEG_CODE (0x1f << 16) #define SUN4I_STA_START (0x03 << 16) #define SUN4I_STA_ID28_21 (0x02 << 16) #define SUN4I_STA_ID20_18 (0x06 << 16) #define SUN4I_STA_SRTR (0x04 << 16) #define SUN4I_STA_IDE (0x05 << 16) #define SUN4I_STA_ID17_13 (0x07 << 16) #define SUN4I_STA_ID12_5 (0x0f << 16) #define SUN4I_STA_ID4_0 (0x0e << 16) #define SUN4I_STA_RTR (0x0c << 16) #define SUN4I_STA_RB1 (0x0d << 16) #define SUN4I_STA_RB0 (0x09 << 16) #define SUN4I_STA_DLEN (0x0b << 16) #define SUN4I_STA_DATA_FIELD (0x0a << 16) #define SUN4I_STA_CRC_SEQUENCE (0x08 << 16) #define SUN4I_STA_CRC_DELIMITER (0x18 << 16) #define SUN4I_STA_ACK (0x19 << 16) #define SUN4I_STA_ACK_DELIMITER (0x1b << 16) #define SUN4I_STA_END (0x1a << 16) #define SUN4I_STA_INTERMISSION (0x12 << 16) #define SUN4I_STA_ACTIVE_ERROR (0x11 << 16) #define SUN4I_STA_PASSIVE_ERROR (0x16 << 16) #define SUN4I_STA_TOLERATE_DOMINANT_BITS (0x13 << 16) #define SUN4I_STA_ERROR_DELIMITER (0x17 << 16) #define SUN4I_STA_OVERLOAD (0x1c << 16) #define SUN4I_STA_BUS_OFF BIT(7) #define SUN4I_STA_ERR_STA BIT(6) #define SUN4I_STA_TRANS_BUSY BIT(5) #define SUN4I_STA_RCV_BUSY BIT(4) #define SUN4I_STA_TRANS_OVER BIT(3) #define SUN4I_STA_TBUF_RDY BIT(2) #define SUN4I_STA_DATA_ORUN BIT(1) #define SUN4I_STA_RBUF_RDY BIT(0) /* interrupt register (r) * offset:0x000c default:0x0000_0000 */ #define SUN4I_INT_BUS_ERR BIT(7) #define SUN4I_INT_ARB_LOST BIT(6) #define SUN4I_INT_ERR_PASSIVE BIT(5) #define SUN4I_INT_WAKEUP BIT(4) #define SUN4I_INT_DATA_OR BIT(3) #define SUN4I_INT_ERR_WRN BIT(2) #define SUN4I_INT_TBUF_VLD BIT(1) #define SUN4I_INT_RBUF_VLD BIT(0) /* interrupt enable register (r/w) * offset:0x0010 default:0x0000_0000 */ #define SUN4I_INTEN_BERR BIT(7) #define SUN4I_INTEN_ARB_LOST BIT(6) #define SUN4I_INTEN_ERR_PASSIVE BIT(5) #define SUN4I_INTEN_WAKEUP BIT(4) #define SUN4I_INTEN_OR BIT(3) #define SUN4I_INTEN_ERR_WRN BIT(2) #define SUN4I_INTEN_TX BIT(1) #define SUN4I_INTEN_RX BIT(0) /* error code */ #define SUN4I_ERR_INRCV (0x1 << 5) #define SUN4I_ERR_INTRANS (0x0 << 5) /* filter mode */ #define SUN4I_FILTER_CLOSE 0 #define SUN4I_SINGLE_FLTER_MODE 1 #define SUN4I_DUAL_FILTER_MODE 2 /* message buffer flags */ #define SUN4I_MSG_EFF_FLAG BIT(7) #define SUN4I_MSG_RTR_FLAG BIT(6) /* max. number of interrupts handled in ISR */ #define SUN4I_CAN_MAX_IRQ 20 #define SUN4I_MODE_MAX_RETRIES 100 struct sun4ican_priv { struct can_priv can; void __iomem *base; struct clk *clk; spinlock_t cmdreg_lock; /* lock for concurrent cmd register writes */ }; static const struct can_bittiming_const sun4ican_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 = 64, .brp_inc = 1, }; static void sun4i_can_write_cmdreg(struct sun4ican_priv *priv, u8 val) { unsigned long flags; spin_lock_irqsave(&priv->cmdreg_lock, flags); writel(val, priv->base + SUN4I_REG_CMD_ADDR); spin_unlock_irqrestore(&priv->cmdreg_lock, flags); } static int set_normal_mode(struct net_device *dev) { struct sun4ican_priv *priv = netdev_priv(dev); int retry = SUN4I_MODE_MAX_RETRIES; u32 mod_reg_val = 0; do { mod_reg_val = readl(priv->base + SUN4I_REG_MSEL_ADDR); mod_reg_val &= ~SUN4I_MSEL_RESET_MODE; writel(mod_reg_val, priv->base + SUN4I_REG_MSEL_ADDR); } while (retry-- && (mod_reg_val & SUN4I_MSEL_RESET_MODE)); if (readl(priv->base + SUN4I_REG_MSEL_ADDR) & SUN4I_MSEL_RESET_MODE) { netdev_err(dev, "setting controller into normal mode failed!\n"); return -ETIMEDOUT; } return 0; } static int set_reset_mode(struct net_device *dev) { struct sun4ican_priv *priv = netdev_priv(dev); int retry = SUN4I_MODE_MAX_RETRIES; u32 mod_reg_val = 0; do { mod_reg_val = readl(priv->base + SUN4I_REG_MSEL_ADDR); mod_reg_val |= SUN4I_MSEL_RESET_MODE; writel(mod_reg_val, priv->base + SUN4I_REG_MSEL_ADDR); } while (retry-- && !(mod_reg_val & SUN4I_MSEL_RESET_MODE)); if (!(readl(priv->base + SUN4I_REG_MSEL_ADDR) & SUN4I_MSEL_RESET_MODE)) { netdev_err(dev, "setting controller into reset mode failed!\n"); return -ETIMEDOUT; } return 0; } /* bittiming is called in reset_mode only */ static int sun4ican_set_bittiming(struct net_device *dev) { struct sun4ican_priv *priv = netdev_priv(dev); struct can_bittiming *bt = &priv->can.bittiming; u32 cfg; cfg = ((bt->brp - 1) & 0x3FF) | (((bt->sjw - 1) & 0x3) << 14) | (((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) << 16) | (((bt->phase_seg2 - 1) & 0x7) << 20); if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) cfg |= 0x800000; netdev_dbg(dev, "setting BITTIMING=0x%08x\n", cfg); writel(cfg, priv->base + SUN4I_REG_BTIME_ADDR); return 0; } static int sun4ican_get_berr_counter(const struct net_device *dev, struct can_berr_counter *bec) { struct sun4ican_priv *priv = netdev_priv(dev); u32 errors; int err; err = clk_prepare_enable(priv->clk); if (err) { netdev_err(dev, "could not enable clock\n"); return err; } errors = readl(priv->base + SUN4I_REG_ERRC_ADDR); bec->txerr = errors & 0xFF; bec->rxerr = (errors >> 16) & 0xFF; clk_disable_unprepare(priv->clk); return 0; } static int sun4i_can_start(struct net_device *dev) { struct sun4ican_priv *priv = netdev_priv(dev); int err; u32 mod_reg_val; /* we need to enter the reset mode */ err = set_reset_mode(dev); if (err) { netdev_err(dev, "could not enter reset mode\n"); return err; } /* set filters - we accept all */ writel(0x00000000, priv->base + SUN4I_REG_ACPC_ADDR); writel(0xFFFFFFFF, priv->base + SUN4I_REG_ACPM_ADDR); /* clear error counters and error code capture */ writel(0, priv->base + SUN4I_REG_ERRC_ADDR); /* enable interrupts */ if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) writel(0xFF, priv->base + SUN4I_REG_INTEN_ADDR); else writel(0xFF & ~SUN4I_INTEN_BERR, priv->base + SUN4I_REG_INTEN_ADDR); /* enter the selected mode */ mod_reg_val = readl(priv->base + SUN4I_REG_MSEL_ADDR); if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) mod_reg_val |= SUN4I_MSEL_LOOPBACK_MODE; else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) mod_reg_val |= SUN4I_MSEL_LISTEN_ONLY_MODE; writel(mod_reg_val, priv->base + SUN4I_REG_MSEL_ADDR); err = sun4ican_set_bittiming(dev); if (err) return err; /* we are ready to enter the normal mode */ err = set_normal_mode(dev); if (err) { netdev_err(dev, "could not enter normal mode\n"); return err; } priv->can.state = CAN_STATE_ERROR_ACTIVE; return 0; } static int sun4i_can_stop(struct net_device *dev) { struct sun4ican_priv *priv = netdev_priv(dev); int err; priv->can.state = CAN_STATE_STOPPED; /* we need to enter reset mode */ err = set_reset_mode(dev); if (err) { netdev_err(dev, "could not enter reset mode\n"); return err; } /* disable all interrupts */ writel(0, priv->base + SUN4I_REG_INTEN_ADDR); return 0; } static int sun4ican_set_mode(struct net_device *dev, enum can_mode mode) { int err; switch (mode) { case CAN_MODE_START: err = sun4i_can_start(dev); if (err) { netdev_err(dev, "starting CAN controller failed!\n"); return err; } if (netif_queue_stopped(dev)) netif_wake_queue(dev); break; default: return -EOPNOTSUPP; } return 0; } /* transmit a CAN message * message layout in the sk_buff should be like this: * xx xx xx xx ff ll 00 11 22 33 44 55 66 77 * [ can_id ] [flags] [len] [can data (up to 8 bytes] */ static netdev_tx_t sun4ican_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct sun4ican_priv *priv = netdev_priv(dev); struct can_frame *cf = (struct can_frame *)skb->data; u8 dlc; u32 dreg, msg_flag_n; canid_t id; int i; if (can_dropped_invalid_skb(dev, skb)) return NETDEV_TX_OK; netif_stop_queue(dev); id = cf->can_id; dlc = cf->len; msg_flag_n = dlc; if (id & CAN_RTR_FLAG) msg_flag_n |= SUN4I_MSG_RTR_FLAG; if (id & CAN_EFF_FLAG) { msg_flag_n |= SUN4I_MSG_EFF_FLAG; dreg = SUN4I_REG_BUF5_ADDR; writel((id >> 21) & 0xFF, priv->base + SUN4I_REG_BUF1_ADDR); writel((id >> 13) & 0xFF, priv->base + SUN4I_REG_BUF2_ADDR); writel((id >> 5) & 0xFF, priv->base + SUN4I_REG_BUF3_ADDR); writel((id << 3) & 0xF8, priv->base + SUN4I_REG_BUF4_ADDR); } else { dreg = SUN4I_REG_BUF3_ADDR; writel((id >> 3) & 0xFF, priv->base + SUN4I_REG_BUF1_ADDR); writel((id << 5) & 0xE0, priv->base + SUN4I_REG_BUF2_ADDR); } for (i = 0; i < dlc; i++) writel(cf->data[i], priv->base + (dreg + i * 4)); writel(msg_flag_n, priv->base + SUN4I_REG_BUF0_ADDR); can_put_echo_skb(skb, dev, 0, 0); if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) sun4i_can_write_cmdreg(priv, SUN4I_CMD_SELF_RCV_REQ); else sun4i_can_write_cmdreg(priv, SUN4I_CMD_TRANS_REQ); return NETDEV_TX_OK; } static void sun4i_can_rx(struct net_device *dev) { struct sun4ican_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; struct can_frame *cf; struct sk_buff *skb; u8 fi; u32 dreg; canid_t id; int i; /* create zero'ed CAN frame buffer */ skb = alloc_can_skb(dev, &cf); if (!skb) return; fi = readl(priv->base + SUN4I_REG_BUF0_ADDR); cf->len = can_cc_dlc2len(fi & 0x0F); if (fi & SUN4I_MSG_EFF_FLAG) { dreg = SUN4I_REG_BUF5_ADDR; id = (readl(priv->base + SUN4I_REG_BUF1_ADDR) << 21) | (readl(priv->base + SUN4I_REG_BUF2_ADDR) << 13) | (readl(priv->base + SUN4I_REG_BUF3_ADDR) << 5) | ((readl(priv->base + SUN4I_REG_BUF4_ADDR) >> 3) & 0x1f); id |= CAN_EFF_FLAG; } else { dreg = SUN4I_REG_BUF3_ADDR; id = (readl(priv->base + SUN4I_REG_BUF1_ADDR) << 3) | ((readl(priv->base + SUN4I_REG_BUF2_ADDR) >> 5) & 0x7); } /* remote frame ? */ if (fi & SUN4I_MSG_RTR_FLAG) id |= CAN_RTR_FLAG; else for (i = 0; i < cf->len; i++) cf->data[i] = readl(priv->base + dreg + i * 4); cf->can_id = id; sun4i_can_write_cmdreg(priv, SUN4I_CMD_RELEASE_RBUF); stats->rx_packets++; stats->rx_bytes += cf->len; netif_rx(skb); can_led_event(dev, CAN_LED_EVENT_RX); } static int sun4i_can_err(struct net_device *dev, u8 isrc, u8 status) { struct sun4ican_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; struct can_frame *cf; struct sk_buff *skb; enum can_state state = priv->can.state; enum can_state rx_state, tx_state; unsigned int rxerr, txerr, errc; u32 ecc, alc; /* we don't skip if alloc fails because we want the stats anyhow */ skb = alloc_can_err_skb(dev, &cf); errc = readl(priv->base + SUN4I_REG_ERRC_ADDR); rxerr = (errc >> 16) & 0xFF; txerr = errc & 0xFF; if (skb) { cf->data[6] = txerr; cf->data[7] = rxerr; } if (isrc & SUN4I_INT_DATA_OR) { /* data overrun interrupt */ netdev_dbg(dev, "data overrun interrupt\n"); if (likely(skb)) { cf->can_id |= CAN_ERR_CRTL; cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; } stats->rx_over_errors++; stats->rx_errors++; /* reset the CAN IP by entering reset mode * ignoring timeout error */ set_reset_mode(dev); set_normal_mode(dev); /* clear bit */ sun4i_can_write_cmdreg(priv, SUN4I_CMD_CLEAR_OR_FLAG); } if (isrc & SUN4I_INT_ERR_WRN) { /* error warning interrupt */ netdev_dbg(dev, "error warning interrupt\n"); if (status & SUN4I_STA_BUS_OFF) state = CAN_STATE_BUS_OFF; else if (status & SUN4I_STA_ERR_STA) state = CAN_STATE_ERROR_WARNING; else state = CAN_STATE_ERROR_ACTIVE; } if (isrc & SUN4I_INT_BUS_ERR) { /* bus error interrupt */ netdev_dbg(dev, "bus error interrupt\n"); priv->can.can_stats.bus_error++; stats->rx_errors++; if (likely(skb)) { ecc = readl(priv->base + SUN4I_REG_STA_ADDR); cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; switch (ecc & SUN4I_STA_MASK_ERR) { case SUN4I_STA_BIT_ERR: cf->data[2] |= CAN_ERR_PROT_BIT; break; case SUN4I_STA_FORM_ERR: cf->data[2] |= CAN_ERR_PROT_FORM; break; case SUN4I_STA_STUFF_ERR: cf->data[2] |= CAN_ERR_PROT_STUFF; break; default: cf->data[3] = (ecc & SUN4I_STA_ERR_SEG_CODE) >> 16; break; } /* error occurred during transmission? */ if ((ecc & SUN4I_STA_ERR_DIR) == 0) cf->data[2] |= CAN_ERR_PROT_TX; } } if (isrc & SUN4I_INT_ERR_PASSIVE) { /* error passive interrupt */ netdev_dbg(dev, "error passive interrupt\n"); if (state == CAN_STATE_ERROR_PASSIVE) state = CAN_STATE_ERROR_WARNING; else state = CAN_STATE_ERROR_PASSIVE; } if (isrc & SUN4I_INT_ARB_LOST) { /* arbitration lost interrupt */ netdev_dbg(dev, "arbitration lost interrupt\n"); alc = readl(priv->base + SUN4I_REG_STA_ADDR); priv->can.can_stats.arbitration_lost++; if (likely(skb)) { cf->can_id |= CAN_ERR_LOSTARB; cf->data[0] = (alc >> 8) & 0x1f; } } if (state != priv->can.state) { tx_state = txerr >= rxerr ? state : 0; rx_state = txerr <= rxerr ? state : 0; if (likely(skb)) can_change_state(dev, cf, tx_state, rx_state); else priv->can.state = state; if (state == CAN_STATE_BUS_OFF) can_bus_off(dev); } if (likely(skb)) { stats->rx_packets++; stats->rx_bytes += cf->len; netif_rx(skb); } else { return -ENOMEM; } return 0; } static irqreturn_t sun4i_can_interrupt(int irq, void *dev_id) { struct net_device *dev = (struct net_device *)dev_id; struct sun4ican_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; u8 isrc, status; int n = 0; while ((isrc = readl(priv->base + SUN4I_REG_INT_ADDR)) && (n < SUN4I_CAN_MAX_IRQ)) { n++; status = readl(priv->base + SUN4I_REG_STA_ADDR); if (isrc & SUN4I_INT_WAKEUP) netdev_warn(dev, "wakeup interrupt\n"); if (isrc & SUN4I_INT_TBUF_VLD) { /* transmission complete interrupt */ stats->tx_bytes += readl(priv->base + SUN4I_REG_RBUF_RBACK_START_ADDR) & 0xf; stats->tx_packets++; can_get_echo_skb(dev, 0, NULL); netif_wake_queue(dev); can_led_event(dev, CAN_LED_EVENT_TX); } if ((isrc & SUN4I_INT_RBUF_VLD) && !(isrc & SUN4I_INT_DATA_OR)) { /* receive interrupt - don't read if overrun occurred */ while (status & SUN4I_STA_RBUF_RDY) { /* RX buffer is not empty */ sun4i_can_rx(dev); status = readl(priv->base + SUN4I_REG_STA_ADDR); } } if (isrc & (SUN4I_INT_DATA_OR | SUN4I_INT_ERR_WRN | SUN4I_INT_BUS_ERR | SUN4I_INT_ERR_PASSIVE | SUN4I_INT_ARB_LOST)) { /* error interrupt */ if (sun4i_can_err(dev, isrc, status)) netdev_err(dev, "can't allocate buffer - clearing pending interrupts\n"); } /* clear interrupts */ writel(isrc, priv->base + SUN4I_REG_INT_ADDR); readl(priv->base + SUN4I_REG_INT_ADDR); } if (n >= SUN4I_CAN_MAX_IRQ) netdev_dbg(dev, "%d messages handled in ISR", n); return (n) ? IRQ_HANDLED : IRQ_NONE; } static int sun4ican_open(struct net_device *dev) { struct sun4ican_priv *priv = netdev_priv(dev); int err; /* common open */ err = open_candev(dev); if (err) return err; /* register interrupt handler */ err = request_irq(dev->irq, sun4i_can_interrupt, 0, dev->name, dev); if (err) { netdev_err(dev, "request_irq err: %d\n", err); goto exit_irq; } /* turn on clocking for CAN peripheral block */ err = clk_prepare_enable(priv->clk); if (err) { netdev_err(dev, "could not enable CAN peripheral clock\n"); goto exit_clock; } err = sun4i_can_start(dev); if (err) { netdev_err(dev, "could not start CAN peripheral\n"); goto exit_can_start; } can_led_event(dev, CAN_LED_EVENT_OPEN); netif_start_queue(dev); return 0; exit_can_start: clk_disable_unprepare(priv->clk); exit_clock: free_irq(dev->irq, dev); exit_irq: close_candev(dev); return err; } static int sun4ican_close(struct net_device *dev) { struct sun4ican_priv *priv = netdev_priv(dev); netif_stop_queue(dev); sun4i_can_stop(dev); clk_disable_unprepare(priv->clk); free_irq(dev->irq, dev); close_candev(dev); can_led_event(dev, CAN_LED_EVENT_STOP); return 0; } static const struct net_device_ops sun4ican_netdev_ops = { .ndo_open = sun4ican_open, .ndo_stop = sun4ican_close, .ndo_start_xmit = sun4ican_start_xmit, }; static const struct of_device_id sun4ican_of_match[] = { {.compatible = "allwinner,sun4i-a10-can"}, {}, }; MODULE_DEVICE_TABLE(of, sun4ican_of_match); static int sun4ican_remove(struct platform_device *pdev) { struct net_device *dev = platform_get_drvdata(pdev); unregister_netdev(dev); free_candev(dev); return 0; } static int sun4ican_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct clk *clk; void __iomem *addr; int err, irq; struct net_device *dev; struct sun4ican_priv *priv; clk = of_clk_get(np, 0); if (IS_ERR(clk)) { dev_err(&pdev->dev, "unable to request clock\n"); err = -ENODEV; goto exit; } irq = platform_get_irq(pdev, 0); if (irq < 0) { err = -ENODEV; goto exit; } addr = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(addr)) { err = PTR_ERR(addr); goto exit; } dev = alloc_candev(sizeof(struct sun4ican_priv), 1); if (!dev) { dev_err(&pdev->dev, "could not allocate memory for CAN device\n"); err = -ENOMEM; goto exit; } dev->netdev_ops = &sun4ican_netdev_ops; dev->irq = irq; dev->flags |= IFF_ECHO; priv = netdev_priv(dev); priv->can.clock.freq = clk_get_rate(clk); priv->can.bittiming_const = &sun4ican_bittiming_const; priv->can.do_set_mode = sun4ican_set_mode; priv->can.do_get_berr_counter = sun4ican_get_berr_counter; priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING | CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_3_SAMPLES; priv->base = addr; priv->clk = clk; spin_lock_init(&priv->cmdreg_lock); platform_set_drvdata(pdev, dev); SET_NETDEV_DEV(dev, &pdev->dev); err = register_candev(dev); if (err) { dev_err(&pdev->dev, "registering %s failed (err=%d)\n", DRV_NAME, err); goto exit_free; } devm_can_led_init(dev); dev_info(&pdev->dev, "device registered (base=%p, irq=%d)\n", priv->base, dev->irq); return 0; exit_free: free_candev(dev); exit: return err; } static struct platform_driver sun4i_can_driver = { .driver = { .name = DRV_NAME, .of_match_table = sun4ican_of_match, }, .probe = sun4ican_probe, .remove = sun4ican_remove, }; module_platform_driver(sun4i_can_driver); MODULE_AUTHOR("Peter Chen "); MODULE_AUTHOR("Gerhard Bertelsmann "); MODULE_LICENSE("Dual BSD/GPL"); MODULE_DESCRIPTION("CAN driver for Allwinner SoCs (A10/A20)");