diff options
Diffstat (limited to 'drivers/net/can/sun4i_can.c')
| -rw-r--r-- | drivers/net/can/sun4i_can.c | 863 |
1 files changed, 863 insertions, 0 deletions
diff --git a/drivers/net/can/sun4i_can.c b/drivers/net/can/sun4i_can.c new file mode 100644 index 000000000..093fc9a52 --- /dev/null +++ b/drivers/net/can/sun4i_can.c @@ -0,0 +1,863 @@ +/* + * 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 <oliver.hartkopp@volkswagen.de> + * Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com> + * 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 <linux/netdevice.h> +#include <linux/can.h> +#include <linux/can/dev.h> +#include <linux/can/error.h> +#include <linux/can/led.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> + +#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->can_dlc; + 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); + + 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->can_dlc = get_can_dlc(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->can_dlc; 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->can_dlc; + 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++; + stats->tx_errors++; + 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->can_dlc; + 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); + 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 resource *mem; + 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) { + dev_err(&pdev->dev, "could not get a valid irq\n"); + err = -ENODEV; + goto exit; + } + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + addr = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(addr)) { + err = -EBUSY; + 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 <xingkongcp@gmail.com>"); +MODULE_AUTHOR("Gerhard Bertelsmann <info@gerhard-bertelsmann.de>"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_DESCRIPTION("CAN driver for Allwinner SoCs (A10/A20)"); |