| /* |
| * 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 (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 (skb && state != CAN_STATE_BUS_OFF) { |
| cf->data[6] = txerr; |
| cf->data[7] = rxerr; |
| } |
| 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)"); |