| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Appana Durga Kedareswara Rao | 3940 | 66.29% | 2 | 12.50% |
| Anssi Hannula | 1979 | 33.29% | 9 | 56.25% |
| Jeppe Ledet-Pedersen | 13 | 0.22% | 1 | 6.25% |
| Marc Kleine-Budde | 5 | 0.08% | 1 | 6.25% |
| Sudip Mukherjee | 3 | 0.05% | 1 | 6.25% |
| Eric Dumazet | 3 | 0.05% | 1 | 6.25% |
| Oliver Hartkopp | 1 | 0.02% | 1 | 6.25% |
| Total | 5944 | 16 |
/* Xilinx CAN device driver * * Copyright (C) 2012 - 2014 Xilinx, Inc. * Copyright (C) 2009 PetaLogix. All rights reserved. * Copyright (C) 2017 - 2018 Sandvik Mining and Construction Oy * * Description: * This driver is developed for Axi CAN IP and for Zynq CANPS Controller. * 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, either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/clk.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/netdevice.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/skbuff.h> #include <linux/spinlock.h> #include <linux/string.h> #include <linux/types.h> #include <linux/can/dev.h> #include <linux/can/error.h> #include <linux/can/led.h> #include <linux/pm_runtime.h> #define DRIVER_NAME "xilinx_can" /* CAN registers set */ enum xcan_reg { XCAN_SRR_OFFSET = 0x00, /* Software reset */ XCAN_MSR_OFFSET = 0x04, /* Mode select */ XCAN_BRPR_OFFSET = 0x08, /* Baud rate prescaler */ XCAN_BTR_OFFSET = 0x0C, /* Bit timing */ XCAN_ECR_OFFSET = 0x10, /* Error counter */ XCAN_ESR_OFFSET = 0x14, /* Error status */ XCAN_SR_OFFSET = 0x18, /* Status */ XCAN_ISR_OFFSET = 0x1C, /* Interrupt status */ XCAN_IER_OFFSET = 0x20, /* Interrupt enable */ XCAN_ICR_OFFSET = 0x24, /* Interrupt clear */ /* not on CAN FD cores */ XCAN_TXFIFO_OFFSET = 0x30, /* TX FIFO base */ XCAN_RXFIFO_OFFSET = 0x50, /* RX FIFO base */ XCAN_AFR_OFFSET = 0x60, /* Acceptance Filter */ /* only on CAN FD cores */ XCAN_TRR_OFFSET = 0x0090, /* TX Buffer Ready Request */ XCAN_AFR_EXT_OFFSET = 0x00E0, /* Acceptance Filter */ XCAN_FSR_OFFSET = 0x00E8, /* RX FIFO Status */ XCAN_TXMSG_BASE_OFFSET = 0x0100, /* TX Message Space */ XCAN_RXMSG_BASE_OFFSET = 0x1100, /* RX Message Space */ }; #define XCAN_FRAME_ID_OFFSET(frame_base) ((frame_base) + 0x00) #define XCAN_FRAME_DLC_OFFSET(frame_base) ((frame_base) + 0x04) #define XCAN_FRAME_DW1_OFFSET(frame_base) ((frame_base) + 0x08) #define XCAN_FRAME_DW2_OFFSET(frame_base) ((frame_base) + 0x0C) #define XCAN_CANFD_FRAME_SIZE 0x48 #define XCAN_TXMSG_FRAME_OFFSET(n) (XCAN_TXMSG_BASE_OFFSET + \ XCAN_CANFD_FRAME_SIZE * (n)) #define XCAN_RXMSG_FRAME_OFFSET(n) (XCAN_RXMSG_BASE_OFFSET + \ XCAN_CANFD_FRAME_SIZE * (n)) /* the single TX mailbox used by this driver on CAN FD HW */ #define XCAN_TX_MAILBOX_IDX 0 /* CAN register bit masks - XCAN_<REG>_<BIT>_MASK */ #define XCAN_SRR_CEN_MASK 0x00000002 /* CAN enable */ #define XCAN_SRR_RESET_MASK 0x00000001 /* Soft Reset the CAN core */ #define XCAN_MSR_LBACK_MASK 0x00000002 /* Loop back mode select */ #define XCAN_MSR_SLEEP_MASK 0x00000001 /* Sleep mode select */ #define XCAN_BRPR_BRP_MASK 0x000000FF /* Baud rate prescaler */ #define XCAN_BTR_SJW_MASK 0x00000180 /* Synchronous jump width */ #define XCAN_BTR_TS2_MASK 0x00000070 /* Time segment 2 */ #define XCAN_BTR_TS1_MASK 0x0000000F /* Time segment 1 */ #define XCAN_BTR_SJW_MASK_CANFD 0x000F0000 /* Synchronous jump width */ #define XCAN_BTR_TS2_MASK_CANFD 0x00000F00 /* Time segment 2 */ #define XCAN_BTR_TS1_MASK_CANFD 0x0000003F /* Time segment 1 */ #define XCAN_ECR_REC_MASK 0x0000FF00 /* Receive error counter */ #define XCAN_ECR_TEC_MASK 0x000000FF /* Transmit error counter */ #define XCAN_ESR_ACKER_MASK 0x00000010 /* ACK error */ #define XCAN_ESR_BERR_MASK 0x00000008 /* Bit error */ #define XCAN_ESR_STER_MASK 0x00000004 /* Stuff error */ #define XCAN_ESR_FMER_MASK 0x00000002 /* Form error */ #define XCAN_ESR_CRCER_MASK 0x00000001 /* CRC error */ #define XCAN_SR_TXFLL_MASK 0x00000400 /* TX FIFO is full */ #define XCAN_SR_ESTAT_MASK 0x00000180 /* Error status */ #define XCAN_SR_ERRWRN_MASK 0x00000040 /* Error warning */ #define XCAN_SR_NORMAL_MASK 0x00000008 /* Normal mode */ #define XCAN_SR_LBACK_MASK 0x00000002 /* Loop back mode */ #define XCAN_SR_CONFIG_MASK 0x00000001 /* Configuration mode */ #define XCAN_IXR_RXMNF_MASK 0x00020000 /* RX match not finished */ #define XCAN_IXR_TXFEMP_MASK 0x00004000 /* TX FIFO Empty */ #define XCAN_IXR_WKUP_MASK 0x00000800 /* Wake up interrupt */ #define XCAN_IXR_SLP_MASK 0x00000400 /* Sleep interrupt */ #define XCAN_IXR_BSOFF_MASK 0x00000200 /* Bus off interrupt */ #define XCAN_IXR_ERROR_MASK 0x00000100 /* Error interrupt */ #define XCAN_IXR_RXNEMP_MASK 0x00000080 /* RX FIFO NotEmpty intr */ #define XCAN_IXR_RXOFLW_MASK 0x00000040 /* RX FIFO Overflow intr */ #define XCAN_IXR_RXOK_MASK 0x00000010 /* Message received intr */ #define XCAN_IXR_TXFLL_MASK 0x00000004 /* Tx FIFO Full intr */ #define XCAN_IXR_TXOK_MASK 0x00000002 /* TX successful intr */ #define XCAN_IXR_ARBLST_MASK 0x00000001 /* Arbitration lost intr */ #define XCAN_IDR_ID1_MASK 0xFFE00000 /* Standard msg identifier */ #define XCAN_IDR_SRR_MASK 0x00100000 /* Substitute remote TXreq */ #define XCAN_IDR_IDE_MASK 0x00080000 /* Identifier extension */ #define XCAN_IDR_ID2_MASK 0x0007FFFE /* Extended message ident */ #define XCAN_IDR_RTR_MASK 0x00000001 /* Remote TX request */ #define XCAN_DLCR_DLC_MASK 0xF0000000 /* Data length code */ #define XCAN_FSR_FL_MASK 0x00003F00 /* RX Fill Level */ #define XCAN_FSR_IRI_MASK 0x00000080 /* RX Increment Read Index */ #define XCAN_FSR_RI_MASK 0x0000001F /* RX Read Index */ /* CAN register bit shift - XCAN_<REG>_<BIT>_SHIFT */ #define XCAN_BTR_SJW_SHIFT 7 /* Synchronous jump width */ #define XCAN_BTR_TS2_SHIFT 4 /* Time segment 2 */ #define XCAN_BTR_SJW_SHIFT_CANFD 16 /* Synchronous jump width */ #define XCAN_BTR_TS2_SHIFT_CANFD 8 /* Time segment 2 */ #define XCAN_IDR_ID1_SHIFT 21 /* Standard Messg Identifier */ #define XCAN_IDR_ID2_SHIFT 1 /* Extended Message Identifier */ #define XCAN_DLCR_DLC_SHIFT 28 /* Data length code */ #define XCAN_ESR_REC_SHIFT 8 /* Rx Error Count */ /* CAN frame length constants */ #define XCAN_FRAME_MAX_DATA_LEN 8 #define XCAN_TIMEOUT (1 * HZ) /* TX-FIFO-empty interrupt available */ #define XCAN_FLAG_TXFEMP 0x0001 /* RX Match Not Finished interrupt available */ #define XCAN_FLAG_RXMNF 0x0002 /* Extended acceptance filters with control at 0xE0 */ #define XCAN_FLAG_EXT_FILTERS 0x0004 /* TX mailboxes instead of TX FIFO */ #define XCAN_FLAG_TX_MAILBOXES 0x0008 /* RX FIFO with each buffer in separate registers at 0x1100 * instead of the regular FIFO at 0x50 */ #define XCAN_FLAG_RX_FIFO_MULTI 0x0010 struct xcan_devtype_data { unsigned int flags; const struct can_bittiming_const *bittiming_const; const char *bus_clk_name; unsigned int btr_ts2_shift; unsigned int btr_sjw_shift; }; /** * struct xcan_priv - This definition define CAN driver instance * @can: CAN private data structure. * @tx_lock: Lock for synchronizing TX interrupt handling * @tx_head: Tx CAN packets ready to send on the queue * @tx_tail: Tx CAN packets successfully sended on the queue * @tx_max: Maximum number packets the driver can send * @napi: NAPI structure * @read_reg: For reading data from CAN registers * @write_reg: For writing data to CAN registers * @dev: Network device data structure * @reg_base: Ioremapped address to registers * @irq_flags: For request_irq() * @bus_clk: Pointer to struct clk * @can_clk: Pointer to struct clk * @devtype: Device type specific constants */ struct xcan_priv { struct can_priv can; spinlock_t tx_lock; unsigned int tx_head; unsigned int tx_tail; unsigned int tx_max; struct napi_struct napi; u32 (*read_reg)(const struct xcan_priv *priv, enum xcan_reg reg); void (*write_reg)(const struct xcan_priv *priv, enum xcan_reg reg, u32 val); struct device *dev; void __iomem *reg_base; unsigned long irq_flags; struct clk *bus_clk; struct clk *can_clk; struct xcan_devtype_data devtype; }; /* CAN Bittiming constants as per Xilinx CAN specs */ static const struct can_bittiming_const xcan_bittiming_const = { .name = DRIVER_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, }; static const struct can_bittiming_const xcan_bittiming_const_canfd = { .name = DRIVER_NAME, .tseg1_min = 1, .tseg1_max = 64, .tseg2_min = 1, .tseg2_max = 16, .sjw_max = 16, .brp_min = 1, .brp_max = 256, .brp_inc = 1, }; /** * xcan_write_reg_le - Write a value to the device register little endian * @priv: Driver private data structure * @reg: Register offset * @val: Value to write at the Register offset * * Write data to the paricular CAN register */ static void xcan_write_reg_le(const struct xcan_priv *priv, enum xcan_reg reg, u32 val) { iowrite32(val, priv->reg_base + reg); } /** * xcan_read_reg_le - Read a value from the device register little endian * @priv: Driver private data structure * @reg: Register offset * * Read data from the particular CAN register * Return: value read from the CAN register */ static u32 xcan_read_reg_le(const struct xcan_priv *priv, enum xcan_reg reg) { return ioread32(priv->reg_base + reg); } /** * xcan_write_reg_be - Write a value to the device register big endian * @priv: Driver private data structure * @reg: Register offset * @val: Value to write at the Register offset * * Write data to the paricular CAN register */ static void xcan_write_reg_be(const struct xcan_priv *priv, enum xcan_reg reg, u32 val) { iowrite32be(val, priv->reg_base + reg); } /** * xcan_read_reg_be - Read a value from the device register big endian * @priv: Driver private data structure * @reg: Register offset * * Read data from the particular CAN register * Return: value read from the CAN register */ static u32 xcan_read_reg_be(const struct xcan_priv *priv, enum xcan_reg reg) { return ioread32be(priv->reg_base + reg); } /** * xcan_rx_int_mask - Get the mask for the receive interrupt * @priv: Driver private data structure * * Return: The receive interrupt mask used by the driver on this HW */ static u32 xcan_rx_int_mask(const struct xcan_priv *priv) { /* RXNEMP is better suited for our use case as it cannot be cleared * while the FIFO is non-empty, but CAN FD HW does not have it */ if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI) return XCAN_IXR_RXOK_MASK; else return XCAN_IXR_RXNEMP_MASK; } /** * set_reset_mode - Resets the CAN device mode * @ndev: Pointer to net_device structure * * This is the driver reset mode routine.The driver * enters into configuration mode. * * Return: 0 on success and failure value on error */ static int set_reset_mode(struct net_device *ndev) { struct xcan_priv *priv = netdev_priv(ndev); unsigned long timeout; priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK); timeout = jiffies + XCAN_TIMEOUT; while (!(priv->read_reg(priv, XCAN_SR_OFFSET) & XCAN_SR_CONFIG_MASK)) { if (time_after(jiffies, timeout)) { netdev_warn(ndev, "timed out for config mode\n"); return -ETIMEDOUT; } usleep_range(500, 10000); } /* reset clears FIFOs */ priv->tx_head = 0; priv->tx_tail = 0; return 0; } /** * xcan_set_bittiming - CAN set bit timing routine * @ndev: Pointer to net_device structure * * This is the driver set bittiming routine. * Return: 0 on success and failure value on error */ static int xcan_set_bittiming(struct net_device *ndev) { struct xcan_priv *priv = netdev_priv(ndev); struct can_bittiming *bt = &priv->can.bittiming; u32 btr0, btr1; u32 is_config_mode; /* Check whether Xilinx CAN is in configuration mode. * It cannot set bit timing if Xilinx CAN is not in configuration mode. */ is_config_mode = priv->read_reg(priv, XCAN_SR_OFFSET) & XCAN_SR_CONFIG_MASK; if (!is_config_mode) { netdev_alert(ndev, "BUG! Cannot set bittiming - CAN is not in config mode\n"); return -EPERM; } /* Setting Baud Rate prescalar value in BRPR Register */ btr0 = (bt->brp - 1); /* Setting Time Segment 1 in BTR Register */ btr1 = (bt->prop_seg + bt->phase_seg1 - 1); /* Setting Time Segment 2 in BTR Register */ btr1 |= (bt->phase_seg2 - 1) << priv->devtype.btr_ts2_shift; /* Setting Synchronous jump width in BTR Register */ btr1 |= (bt->sjw - 1) << priv->devtype.btr_sjw_shift; priv->write_reg(priv, XCAN_BRPR_OFFSET, btr0); priv->write_reg(priv, XCAN_BTR_OFFSET, btr1); netdev_dbg(ndev, "BRPR=0x%08x, BTR=0x%08x\n", priv->read_reg(priv, XCAN_BRPR_OFFSET), priv->read_reg(priv, XCAN_BTR_OFFSET)); return 0; } /** * xcan_chip_start - This the drivers start routine * @ndev: Pointer to net_device structure * * This is the drivers start routine. * Based on the State of the CAN device it puts * the CAN device into a proper mode. * * Return: 0 on success and failure value on error */ static int xcan_chip_start(struct net_device *ndev) { struct xcan_priv *priv = netdev_priv(ndev); u32 reg_msr, reg_sr_mask; int err; unsigned long timeout; u32 ier; /* Check if it is in reset mode */ err = set_reset_mode(ndev); if (err < 0) return err; err = xcan_set_bittiming(ndev); if (err < 0) return err; /* Enable interrupts */ ier = XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK | XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK | XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK | XCAN_IXR_ARBLST_MASK | xcan_rx_int_mask(priv); if (priv->devtype.flags & XCAN_FLAG_RXMNF) ier |= XCAN_IXR_RXMNF_MASK; priv->write_reg(priv, XCAN_IER_OFFSET, ier); /* Check whether it is loopback mode or normal mode */ if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { reg_msr = XCAN_MSR_LBACK_MASK; reg_sr_mask = XCAN_SR_LBACK_MASK; } else { reg_msr = 0x0; reg_sr_mask = XCAN_SR_NORMAL_MASK; } /* enable the first extended filter, if any, as cores with extended * filtering default to non-receipt if all filters are disabled */ if (priv->devtype.flags & XCAN_FLAG_EXT_FILTERS) priv->write_reg(priv, XCAN_AFR_EXT_OFFSET, 0x00000001); priv->write_reg(priv, XCAN_MSR_OFFSET, reg_msr); priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK); timeout = jiffies + XCAN_TIMEOUT; while (!(priv->read_reg(priv, XCAN_SR_OFFSET) & reg_sr_mask)) { if (time_after(jiffies, timeout)) { netdev_warn(ndev, "timed out for correct mode\n"); return -ETIMEDOUT; } } netdev_dbg(ndev, "status:#x%08x\n", priv->read_reg(priv, XCAN_SR_OFFSET)); priv->can.state = CAN_STATE_ERROR_ACTIVE; return 0; } /** * xcan_do_set_mode - This sets the mode of the driver * @ndev: Pointer to net_device structure * @mode: Tells the mode of the driver * * This check the drivers state and calls the * the corresponding modes to set. * * Return: 0 on success and failure value on error */ static int xcan_do_set_mode(struct net_device *ndev, enum can_mode mode) { int ret; switch (mode) { case CAN_MODE_START: ret = xcan_chip_start(ndev); if (ret < 0) { netdev_err(ndev, "xcan_chip_start failed!\n"); return ret; } netif_wake_queue(ndev); break; default: ret = -EOPNOTSUPP; break; } return ret; } /** * xcan_write_frame - Write a frame to HW * @skb: sk_buff pointer that contains data to be Txed * @frame_offset: Register offset to write the frame to */ static void xcan_write_frame(struct xcan_priv *priv, struct sk_buff *skb, int frame_offset) { u32 id, dlc, data[2] = {0, 0}; struct can_frame *cf = (struct can_frame *)skb->data; /* Watch carefully on the bit sequence */ if (cf->can_id & CAN_EFF_FLAG) { /* Extended CAN ID format */ id = ((cf->can_id & CAN_EFF_MASK) << XCAN_IDR_ID2_SHIFT) & XCAN_IDR_ID2_MASK; id |= (((cf->can_id & CAN_EFF_MASK) >> (CAN_EFF_ID_BITS-CAN_SFF_ID_BITS)) << XCAN_IDR_ID1_SHIFT) & XCAN_IDR_ID1_MASK; /* The substibute remote TX request bit should be "1" * for extended frames as in the Xilinx CAN datasheet */ id |= XCAN_IDR_IDE_MASK | XCAN_IDR_SRR_MASK; if (cf->can_id & CAN_RTR_FLAG) /* Extended frames remote TX request */ id |= XCAN_IDR_RTR_MASK; } else { /* Standard CAN ID format */ id = ((cf->can_id & CAN_SFF_MASK) << XCAN_IDR_ID1_SHIFT) & XCAN_IDR_ID1_MASK; if (cf->can_id & CAN_RTR_FLAG) /* Standard frames remote TX request */ id |= XCAN_IDR_SRR_MASK; } dlc = cf->can_dlc << XCAN_DLCR_DLC_SHIFT; if (cf->can_dlc > 0) data[0] = be32_to_cpup((__be32 *)(cf->data + 0)); if (cf->can_dlc > 4) data[1] = be32_to_cpup((__be32 *)(cf->data + 4)); priv->write_reg(priv, XCAN_FRAME_ID_OFFSET(frame_offset), id); /* If the CAN frame is RTR frame this write triggers transmission * (not on CAN FD) */ priv->write_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_offset), dlc); if (!(cf->can_id & CAN_RTR_FLAG)) { priv->write_reg(priv, XCAN_FRAME_DW1_OFFSET(frame_offset), data[0]); /* If the CAN frame is Standard/Extended frame this * write triggers transmission (not on CAN FD) */ priv->write_reg(priv, XCAN_FRAME_DW2_OFFSET(frame_offset), data[1]); } } /** * xcan_start_xmit_fifo - Starts the transmission (FIFO mode) * * Return: 0 on success, -ENOSPC if FIFO is full. */ static int xcan_start_xmit_fifo(struct sk_buff *skb, struct net_device *ndev) { struct xcan_priv *priv = netdev_priv(ndev); unsigned long flags; /* Check if the TX buffer is full */ if (unlikely(priv->read_reg(priv, XCAN_SR_OFFSET) & XCAN_SR_TXFLL_MASK)) return -ENOSPC; can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max); spin_lock_irqsave(&priv->tx_lock, flags); priv->tx_head++; xcan_write_frame(priv, skb, XCAN_TXFIFO_OFFSET); /* Clear TX-FIFO-empty interrupt for xcan_tx_interrupt() */ if (priv->tx_max > 1) priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXFEMP_MASK); /* Check if the TX buffer is full */ if ((priv->tx_head - priv->tx_tail) == priv->tx_max) netif_stop_queue(ndev); spin_unlock_irqrestore(&priv->tx_lock, flags); return 0; } /** * xcan_start_xmit_mailbox - Starts the transmission (mailbox mode) * * Return: 0 on success, -ENOSPC if there is no space */ static int xcan_start_xmit_mailbox(struct sk_buff *skb, struct net_device *ndev) { struct xcan_priv *priv = netdev_priv(ndev); unsigned long flags; if (unlikely(priv->read_reg(priv, XCAN_TRR_OFFSET) & BIT(XCAN_TX_MAILBOX_IDX))) return -ENOSPC; can_put_echo_skb(skb, ndev, 0); spin_lock_irqsave(&priv->tx_lock, flags); priv->tx_head++; xcan_write_frame(priv, skb, XCAN_TXMSG_FRAME_OFFSET(XCAN_TX_MAILBOX_IDX)); /* Mark buffer as ready for transmit */ priv->write_reg(priv, XCAN_TRR_OFFSET, BIT(XCAN_TX_MAILBOX_IDX)); netif_stop_queue(ndev); spin_unlock_irqrestore(&priv->tx_lock, flags); return 0; } /** * xcan_start_xmit - Starts the transmission * @skb: sk_buff pointer that contains data to be Txed * @ndev: Pointer to net_device structure * * This function is invoked from upper layers to initiate transmission. * * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY when the tx queue is full */ static int xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev) { struct xcan_priv *priv = netdev_priv(ndev); int ret; if (can_dropped_invalid_skb(ndev, skb)) return NETDEV_TX_OK; if (priv->devtype.flags & XCAN_FLAG_TX_MAILBOXES) ret = xcan_start_xmit_mailbox(skb, ndev); else ret = xcan_start_xmit_fifo(skb, ndev); if (ret < 0) { netdev_err(ndev, "BUG!, TX full when queue awake!\n"); netif_stop_queue(ndev); return NETDEV_TX_BUSY; } return NETDEV_TX_OK; } /** * xcan_rx - Is called from CAN isr to complete the received * frame processing * @ndev: Pointer to net_device structure * @frame_base: Register offset to the frame to be read * * This function is invoked from the CAN isr(poll) to process the Rx frames. It * does minimal processing and invokes "netif_receive_skb" to complete further * processing. * Return: 1 on success and 0 on failure. */ static int xcan_rx(struct net_device *ndev, int frame_base) { struct xcan_priv *priv = netdev_priv(ndev); struct net_device_stats *stats = &ndev->stats; struct can_frame *cf; struct sk_buff *skb; u32 id_xcan, dlc, data[2] = {0, 0}; skb = alloc_can_skb(ndev, &cf); if (unlikely(!skb)) { stats->rx_dropped++; return 0; } /* Read a frame from Xilinx zynq CANPS */ id_xcan = priv->read_reg(priv, XCAN_FRAME_ID_OFFSET(frame_base)); dlc = priv->read_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_base)) >> XCAN_DLCR_DLC_SHIFT; /* Change Xilinx CAN data length format to socketCAN data format */ cf->can_dlc = get_can_dlc(dlc); /* Change Xilinx CAN ID format to socketCAN ID format */ if (id_xcan & XCAN_IDR_IDE_MASK) { /* The received frame is an Extended format frame */ cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >> 3; cf->can_id |= (id_xcan & XCAN_IDR_ID2_MASK) >> XCAN_IDR_ID2_SHIFT; cf->can_id |= CAN_EFF_FLAG; if (id_xcan & XCAN_IDR_RTR_MASK) cf->can_id |= CAN_RTR_FLAG; } else { /* The received frame is a standard format frame */ cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >> XCAN_IDR_ID1_SHIFT; if (id_xcan & XCAN_IDR_SRR_MASK) cf->can_id |= CAN_RTR_FLAG; } /* DW1/DW2 must always be read to remove message from RXFIFO */ data[0] = priv->read_reg(priv, XCAN_FRAME_DW1_OFFSET(frame_base)); data[1] = priv->read_reg(priv, XCAN_FRAME_DW2_OFFSET(frame_base)); if (!(cf->can_id & CAN_RTR_FLAG)) { /* Change Xilinx CAN data format to socketCAN data format */ if (cf->can_dlc > 0) *(__be32 *)(cf->data) = cpu_to_be32(data[0]); if (cf->can_dlc > 4) *(__be32 *)(cf->data + 4) = cpu_to_be32(data[1]); } stats->rx_bytes += cf->can_dlc; stats->rx_packets++; netif_receive_skb(skb); return 1; } /** * xcan_current_error_state - Get current error state from HW * @ndev: Pointer to net_device structure * * Checks the current CAN error state from the HW. Note that this * only checks for ERROR_PASSIVE and ERROR_WARNING. * * Return: * ERROR_PASSIVE or ERROR_WARNING if either is active, ERROR_ACTIVE * otherwise. */ static enum can_state xcan_current_error_state(struct net_device *ndev) { struct xcan_priv *priv = netdev_priv(ndev); u32 status = priv->read_reg(priv, XCAN_SR_OFFSET); if ((status & XCAN_SR_ESTAT_MASK) == XCAN_SR_ESTAT_MASK) return CAN_STATE_ERROR_PASSIVE; else if (status & XCAN_SR_ERRWRN_MASK) return CAN_STATE_ERROR_WARNING; else return CAN_STATE_ERROR_ACTIVE; } /** * xcan_set_error_state - Set new CAN error state * @ndev: Pointer to net_device structure * @new_state: The new CAN state to be set * @cf: Error frame to be populated or NULL * * Set new CAN error state for the device, updating statistics and * populating the error frame if given. */ static void xcan_set_error_state(struct net_device *ndev, enum can_state new_state, struct can_frame *cf) { struct xcan_priv *priv = netdev_priv(ndev); u32 ecr = priv->read_reg(priv, XCAN_ECR_OFFSET); u32 txerr = ecr & XCAN_ECR_TEC_MASK; u32 rxerr = (ecr & XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT; enum can_state tx_state = txerr >= rxerr ? new_state : 0; enum can_state rx_state = txerr <= rxerr ? new_state : 0; /* non-ERROR states are handled elsewhere */ if (WARN_ON(new_state > CAN_STATE_ERROR_PASSIVE)) return; can_change_state(ndev, cf, tx_state, rx_state); if (cf) { cf->data[6] = txerr; cf->data[7] = rxerr; } } /** * xcan_update_error_state_after_rxtx - Update CAN error state after RX/TX * @ndev: Pointer to net_device structure * * If the device is in a ERROR-WARNING or ERROR-PASSIVE state, check if * the performed RX/TX has caused it to drop to a lesser state and set * the interface state accordingly. */ static void xcan_update_error_state_after_rxtx(struct net_device *ndev) { struct xcan_priv *priv = netdev_priv(ndev); enum can_state old_state = priv->can.state; enum can_state new_state; /* changing error state due to successful frame RX/TX can only * occur from these states */ if (old_state != CAN_STATE_ERROR_WARNING && old_state != CAN_STATE_ERROR_PASSIVE) return; new_state = xcan_current_error_state(ndev); if (new_state != old_state) { struct sk_buff *skb; struct can_frame *cf; skb = alloc_can_err_skb(ndev, &cf); xcan_set_error_state(ndev, new_state, skb ? cf : NULL); if (skb) { struct net_device_stats *stats = &ndev->stats; stats->rx_packets++; stats->rx_bytes += cf->can_dlc; netif_rx(skb); } } } /** * xcan_err_interrupt - error frame Isr * @ndev: net_device pointer * @isr: interrupt status register value * * This is the CAN error interrupt and it will * check the the type of error and forward the error * frame to upper layers. */ static void xcan_err_interrupt(struct net_device *ndev, u32 isr) { struct xcan_priv *priv = netdev_priv(ndev); struct net_device_stats *stats = &ndev->stats; struct can_frame *cf; struct sk_buff *skb; u32 err_status; skb = alloc_can_err_skb(ndev, &cf); err_status = priv->read_reg(priv, XCAN_ESR_OFFSET); priv->write_reg(priv, XCAN_ESR_OFFSET, err_status); if (isr & XCAN_IXR_BSOFF_MASK) { priv->can.state = CAN_STATE_BUS_OFF; priv->can.can_stats.bus_off++; /* Leave device in Config Mode in bus-off state */ priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK); can_bus_off(ndev); if (skb) cf->can_id |= CAN_ERR_BUSOFF; } else { enum can_state new_state = xcan_current_error_state(ndev); if (new_state != priv->can.state) xcan_set_error_state(ndev, new_state, skb ? cf : NULL); } /* Check for Arbitration lost interrupt */ if (isr & XCAN_IXR_ARBLST_MASK) { priv->can.can_stats.arbitration_lost++; if (skb) { cf->can_id |= CAN_ERR_LOSTARB; cf->data[0] = CAN_ERR_LOSTARB_UNSPEC; } } /* Check for RX FIFO Overflow interrupt */ if (isr & XCAN_IXR_RXOFLW_MASK) { stats->rx_over_errors++; stats->rx_errors++; if (skb) { cf->can_id |= CAN_ERR_CRTL; cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW; } } /* Check for RX Match Not Finished interrupt */ if (isr & XCAN_IXR_RXMNF_MASK) { stats->rx_dropped++; stats->rx_errors++; netdev_err(ndev, "RX match not finished, frame discarded\n"); if (skb) { cf->can_id |= CAN_ERR_CRTL; cf->data[1] |= CAN_ERR_CRTL_UNSPEC; } } /* Check for error interrupt */ if (isr & XCAN_IXR_ERROR_MASK) { if (skb) cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; /* Check for Ack error interrupt */ if (err_status & XCAN_ESR_ACKER_MASK) { stats->tx_errors++; if (skb) { cf->can_id |= CAN_ERR_ACK; cf->data[3] = CAN_ERR_PROT_LOC_ACK; } } /* Check for Bit error interrupt */ if (err_status & XCAN_ESR_BERR_MASK) { stats->tx_errors++; if (skb) { cf->can_id |= CAN_ERR_PROT; cf->data[2] = CAN_ERR_PROT_BIT; } } /* Check for Stuff error interrupt */ if (err_status & XCAN_ESR_STER_MASK) { stats->rx_errors++; if (skb) { cf->can_id |= CAN_ERR_PROT; cf->data[2] = CAN_ERR_PROT_STUFF; } } /* Check for Form error interrupt */ if (err_status & XCAN_ESR_FMER_MASK) { stats->rx_errors++; if (skb) { cf->can_id |= CAN_ERR_PROT; cf->data[2] = CAN_ERR_PROT_FORM; } } /* Check for CRC error interrupt */ if (err_status & XCAN_ESR_CRCER_MASK) { stats->rx_errors++; if (skb) { cf->can_id |= CAN_ERR_PROT; cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ; } } priv->can.can_stats.bus_error++; } if (skb) { stats->rx_packets++; stats->rx_bytes += cf->can_dlc; netif_rx(skb); } netdev_dbg(ndev, "%s: error status register:0x%x\n", __func__, priv->read_reg(priv, XCAN_ESR_OFFSET)); } /** * xcan_state_interrupt - It will check the state of the CAN device * @ndev: net_device pointer * @isr: interrupt status register value * * This will checks the state of the CAN device * and puts the device into appropriate state. */ static void xcan_state_interrupt(struct net_device *ndev, u32 isr) { struct xcan_priv *priv = netdev_priv(ndev); /* Check for Sleep interrupt if set put CAN device in sleep state */ if (isr & XCAN_IXR_SLP_MASK) priv->can.state = CAN_STATE_SLEEPING; /* Check for Wake up interrupt if set put CAN device in Active state */ if (isr & XCAN_IXR_WKUP_MASK) priv->can.state = CAN_STATE_ERROR_ACTIVE; } /** * xcan_rx_fifo_get_next_frame - Get register offset of next RX frame * * Return: Register offset of the next frame in RX FIFO. */ static int xcan_rx_fifo_get_next_frame(struct xcan_priv *priv) { int offset; if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI) { u32 fsr; /* clear RXOK before the is-empty check so that any newly * received frame will reassert it without a race */ priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_RXOK_MASK); fsr = priv->read_reg(priv, XCAN_FSR_OFFSET); /* check if RX FIFO is empty */ if (!(fsr & XCAN_FSR_FL_MASK)) return -ENOENT; offset = XCAN_RXMSG_FRAME_OFFSET(fsr & XCAN_FSR_RI_MASK); } else { /* check if RX FIFO is empty */ if (!(priv->read_reg(priv, XCAN_ISR_OFFSET) & XCAN_IXR_RXNEMP_MASK)) return -ENOENT; /* frames are read from a static offset */ offset = XCAN_RXFIFO_OFFSET; } return offset; } /** * xcan_rx_poll - Poll routine for rx packets (NAPI) * @napi: napi structure pointer * @quota: Max number of rx packets to be processed. * * This is the poll routine for rx part. * It will process the packets maximux quota value. * * Return: number of packets received */ static int xcan_rx_poll(struct napi_struct *napi, int quota) { struct net_device *ndev = napi->dev; struct xcan_priv *priv = netdev_priv(ndev); u32 ier; int work_done = 0; int frame_offset; while ((frame_offset = xcan_rx_fifo_get_next_frame(priv)) >= 0 && (work_done < quota)) { work_done += xcan_rx(ndev, frame_offset); if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI) /* increment read index */ priv->write_reg(priv, XCAN_FSR_OFFSET, XCAN_FSR_IRI_MASK); else /* clear rx-not-empty (will actually clear only if * empty) */ priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_RXNEMP_MASK); } if (work_done) { can_led_event(ndev, CAN_LED_EVENT_RX); xcan_update_error_state_after_rxtx(ndev); } if (work_done < quota) { napi_complete_done(napi, work_done); ier = priv->read_reg(priv, XCAN_IER_OFFSET); ier |= xcan_rx_int_mask(priv); priv->write_reg(priv, XCAN_IER_OFFSET, ier); } return work_done; } /** * xcan_tx_interrupt - Tx Done Isr * @ndev: net_device pointer * @isr: Interrupt status register value */ static void xcan_tx_interrupt(struct net_device *ndev, u32 isr) { struct xcan_priv *priv = netdev_priv(ndev); struct net_device_stats *stats = &ndev->stats; unsigned int frames_in_fifo; int frames_sent = 1; /* TXOK => at least 1 frame was sent */ unsigned long flags; int retries = 0; /* Synchronize with xmit as we need to know the exact number * of frames in the FIFO to stay in sync due to the TXFEMP * handling. * This also prevents a race between netif_wake_queue() and * netif_stop_queue(). */ spin_lock_irqsave(&priv->tx_lock, flags); frames_in_fifo = priv->tx_head - priv->tx_tail; if (WARN_ON_ONCE(frames_in_fifo == 0)) { /* clear TXOK anyway to avoid getting back here */ priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK); spin_unlock_irqrestore(&priv->tx_lock, flags); return; } /* Check if 2 frames were sent (TXOK only means that at least 1 * frame was sent). */ if (frames_in_fifo > 1) { WARN_ON(frames_in_fifo > priv->tx_max); /* Synchronize TXOK and isr so that after the loop: * (1) isr variable is up-to-date at least up to TXOK clear * time. This avoids us clearing a TXOK of a second frame * but not noticing that the FIFO is now empty and thus * marking only a single frame as sent. * (2) No TXOK is left. Having one could mean leaving a * stray TXOK as we might process the associated frame * via TXFEMP handling as we read TXFEMP *after* TXOK * clear to satisfy (1). */ while ((isr & XCAN_IXR_TXOK_MASK) && !WARN_ON(++retries == 100)) { priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK); isr = priv->read_reg(priv, XCAN_ISR_OFFSET); } if (isr & XCAN_IXR_TXFEMP_MASK) { /* nothing in FIFO anymore */ frames_sent = frames_in_fifo; } } else { /* single frame in fifo, just clear TXOK */ priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK); } while (frames_sent--) { stats->tx_bytes += can_get_echo_skb(ndev, priv->tx_tail % priv->tx_max); priv->tx_tail++; stats->tx_packets++; } netif_wake_queue(ndev); spin_unlock_irqrestore(&priv->tx_lock, flags); can_led_event(ndev, CAN_LED_EVENT_TX); xcan_update_error_state_after_rxtx(ndev); } /** * xcan_interrupt - CAN Isr * @irq: irq number * @dev_id: device id poniter * * This is the xilinx CAN Isr. It checks for the type of interrupt * and invokes the corresponding ISR. * * Return: * IRQ_NONE - If CAN device is in sleep mode, IRQ_HANDLED otherwise */ static irqreturn_t xcan_interrupt(int irq, void *dev_id) { struct net_device *ndev = (struct net_device *)dev_id; struct xcan_priv *priv = netdev_priv(ndev); u32 isr, ier; u32 isr_errors; u32 rx_int_mask = xcan_rx_int_mask(priv); /* Get the interrupt status from Xilinx CAN */ isr = priv->read_reg(priv, XCAN_ISR_OFFSET); if (!isr) return IRQ_NONE; /* Check for the type of interrupt and Processing it */ if (isr & (XCAN_IXR_SLP_MASK | XCAN_IXR_WKUP_MASK)) { priv->write_reg(priv, XCAN_ICR_OFFSET, (XCAN_IXR_SLP_MASK | XCAN_IXR_WKUP_MASK)); xcan_state_interrupt(ndev, isr); } /* Check for Tx interrupt and Processing it */ if (isr & XCAN_IXR_TXOK_MASK) xcan_tx_interrupt(ndev, isr); /* Check for the type of error interrupt and Processing it */ isr_errors = isr & (XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK | XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK | XCAN_IXR_RXMNF_MASK); if (isr_errors) { priv->write_reg(priv, XCAN_ICR_OFFSET, isr_errors); xcan_err_interrupt(ndev, isr); } /* Check for the type of receive interrupt and Processing it */ if (isr & rx_int_mask) { ier = priv->read_reg(priv, XCAN_IER_OFFSET); ier &= ~rx_int_mask; priv->write_reg(priv, XCAN_IER_OFFSET, ier); napi_schedule(&priv->napi); } return IRQ_HANDLED; } /** * xcan_chip_stop - Driver stop routine * @ndev: Pointer to net_device structure * * This is the drivers stop routine. It will disable the * interrupts and put the device into configuration mode. */ static void xcan_chip_stop(struct net_device *ndev) { struct xcan_priv *priv = netdev_priv(ndev); /* Disable interrupts and leave the can in configuration mode */ set_reset_mode(ndev); priv->can.state = CAN_STATE_STOPPED; } /** * xcan_open - Driver open routine * @ndev: Pointer to net_device structure * * This is the driver open routine. * Return: 0 on success and failure value on error */ static int xcan_open(struct net_device *ndev) { struct xcan_priv *priv = netdev_priv(ndev); int ret; ret = pm_runtime_get_sync(priv->dev); if (ret < 0) { netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n", __func__, ret); return ret; } ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags, ndev->name, ndev); if (ret < 0) { netdev_err(ndev, "irq allocation for CAN failed\n"); goto err; } /* Set chip into reset mode */ ret = set_reset_mode(ndev); if (ret < 0) { netdev_err(ndev, "mode resetting failed!\n"); goto err_irq; } /* Common open */ ret = open_candev(ndev); if (ret) goto err_irq; ret = xcan_chip_start(ndev); if (ret < 0) { netdev_err(ndev, "xcan_chip_start failed!\n"); goto err_candev; } can_led_event(ndev, CAN_LED_EVENT_OPEN); napi_enable(&priv->napi); netif_start_queue(ndev); return 0; err_candev: close_candev(ndev); err_irq: free_irq(ndev->irq, ndev); err: pm_runtime_put(priv->dev); return ret; } /** * xcan_close - Driver close routine * @ndev: Pointer to net_device structure * * Return: 0 always */ static int xcan_close(struct net_device *ndev) { struct xcan_priv *priv = netdev_priv(ndev); netif_stop_queue(ndev); napi_disable(&priv->napi); xcan_chip_stop(ndev); free_irq(ndev->irq, ndev); close_candev(ndev); can_led_event(ndev, CAN_LED_EVENT_STOP); pm_runtime_put(priv->dev); return 0; } /** * xcan_get_berr_counter - error counter routine * @ndev: Pointer to net_device structure * @bec: Pointer to can_berr_counter structure * * This is the driver error counter routine. * Return: 0 on success and failure value on error */ static int xcan_get_berr_counter(const struct net_device *ndev, struct can_berr_counter *bec) { struct xcan_priv *priv = netdev_priv(ndev); int ret; ret = pm_runtime_get_sync(priv->dev); if (ret < 0) { netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n", __func__, ret); return ret; } bec->txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK; bec->rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT); pm_runtime_put(priv->dev); return 0; } static const struct net_device_ops xcan_netdev_ops = { .ndo_open = xcan_open, .ndo_stop = xcan_close, .ndo_start_xmit = xcan_start_xmit, .ndo_change_mtu = can_change_mtu, }; /** * xcan_suspend - Suspend method for the driver * @dev: Address of the device structure * * Put the driver into low power mode. * Return: 0 on success and failure value on error */ static int __maybe_unused xcan_suspend(struct device *dev) { struct net_device *ndev = dev_get_drvdata(dev); if (netif_running(ndev)) { netif_stop_queue(ndev); netif_device_detach(ndev); xcan_chip_stop(ndev); } return pm_runtime_force_suspend(dev); } /** * xcan_resume - Resume from suspend * @dev: Address of the device structure * * Resume operation after suspend. * Return: 0 on success and failure value on error */ static int __maybe_unused xcan_resume(struct device *dev) { struct net_device *ndev = dev_get_drvdata(dev); int ret; ret = pm_runtime_force_resume(dev); if (ret) { dev_err(dev, "pm_runtime_force_resume failed on resume\n"); return ret; } if (netif_running(ndev)) { ret = xcan_chip_start(ndev); if (ret) { dev_err(dev, "xcan_chip_start failed on resume\n"); return ret; } netif_device_attach(ndev); netif_start_queue(ndev); } return 0; } /** * xcan_runtime_suspend - Runtime suspend method for the driver * @dev: Address of the device structure * * Put the driver into low power mode. * Return: 0 always */ static int __maybe_unused xcan_runtime_suspend(struct device *dev) { struct net_device *ndev = dev_get_drvdata(dev); struct xcan_priv *priv = netdev_priv(ndev); clk_disable_unprepare(priv->bus_clk); clk_disable_unprepare(priv->can_clk); return 0; } /** * xcan_runtime_resume - Runtime resume from suspend * @dev: Address of the device structure * * Resume operation after suspend. * Return: 0 on success and failure value on error */ static int __maybe_unused xcan_runtime_resume(struct device *dev) { struct net_device *ndev = dev_get_drvdata(dev); struct xcan_priv *priv = netdev_priv(ndev); int ret; ret = clk_prepare_enable(priv->bus_clk); if (ret) { dev_err(dev, "Cannot enable clock.\n"); return ret; } ret = clk_prepare_enable(priv->can_clk); if (ret) { dev_err(dev, "Cannot enable clock.\n"); clk_disable_unprepare(priv->bus_clk); return ret; } return 0; } static const struct dev_pm_ops xcan_dev_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(xcan_suspend, xcan_resume) SET_RUNTIME_PM_OPS(xcan_runtime_suspend, xcan_runtime_resume, NULL) }; static const struct xcan_devtype_data xcan_zynq_data = { .bittiming_const = &xcan_bittiming_const, .btr_ts2_shift = XCAN_BTR_TS2_SHIFT, .btr_sjw_shift = XCAN_BTR_SJW_SHIFT, .bus_clk_name = "pclk", }; static const struct xcan_devtype_data xcan_axi_data = { .bittiming_const = &xcan_bittiming_const, .btr_ts2_shift = XCAN_BTR_TS2_SHIFT, .btr_sjw_shift = XCAN_BTR_SJW_SHIFT, .bus_clk_name = "s_axi_aclk", }; static const struct xcan_devtype_data xcan_canfd_data = { .flags = XCAN_FLAG_EXT_FILTERS | XCAN_FLAG_RXMNF | XCAN_FLAG_TX_MAILBOXES | XCAN_FLAG_RX_FIFO_MULTI, .bittiming_const = &xcan_bittiming_const, .btr_ts2_shift = XCAN_BTR_TS2_SHIFT_CANFD, .btr_sjw_shift = XCAN_BTR_SJW_SHIFT_CANFD, .bus_clk_name = "s_axi_aclk", }; /* Match table for OF platform binding */ static const struct of_device_id xcan_of_match[] = { { .compatible = "xlnx,zynq-can-1.0", .data = &xcan_zynq_data }, { .compatible = "xlnx,axi-can-1.00.a", .data = &xcan_axi_data }, { .compatible = "xlnx,canfd-1.0", .data = &xcan_canfd_data }, { /* end of list */ }, }; MODULE_DEVICE_TABLE(of, xcan_of_match); /** * xcan_probe - Platform registration call * @pdev: Handle to the platform device structure * * This function does all the memory allocation and registration for the CAN * device. * * Return: 0 on success and failure value on error */ static int xcan_probe(struct platform_device *pdev) { struct resource *res; /* IO mem resources */ struct net_device *ndev; struct xcan_priv *priv; const struct of_device_id *of_id; const struct xcan_devtype_data *devtype = &xcan_axi_data; void __iomem *addr; int ret; int rx_max, tx_max; int hw_tx_max, hw_rx_max; const char *hw_tx_max_property; /* Get the virtual base address for the device */ res = platform_get_resource(pdev, IORESOURCE_MEM, 0); addr = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(addr)) { ret = PTR_ERR(addr); goto err; } of_id = of_match_device(xcan_of_match, &pdev->dev); if (of_id && of_id->data) devtype = of_id->data; hw_tx_max_property = devtype->flags & XCAN_FLAG_TX_MAILBOXES ? "tx-mailbox-count" : "tx-fifo-depth"; ret = of_property_read_u32(pdev->dev.of_node, hw_tx_max_property, &hw_tx_max); if (ret < 0) { dev_err(&pdev->dev, "missing %s property\n", hw_tx_max_property); goto err; } ret = of_property_read_u32(pdev->dev.of_node, "rx-fifo-depth", &hw_rx_max); if (ret < 0) { dev_err(&pdev->dev, "missing rx-fifo-depth property (mailbox mode is not supported)\n"); goto err; } /* With TX FIFO: * * There is no way to directly figure out how many frames have been * sent when the TXOK interrupt is processed. If TXFEMP * is supported, we can have 2 frames in the FIFO and use TXFEMP * to determine if 1 or 2 frames have been sent. * Theoretically we should be able to use TXFWMEMP to determine up * to 3 frames, but it seems that after putting a second frame in the * FIFO, with watermark at 2 frames, it can happen that TXFWMEMP (less * than 2 frames in FIFO) is set anyway with no TXOK (a frame was * sent), which is not a sensible state - possibly TXFWMEMP is not * completely synchronized with the rest of the bits? * * With TX mailboxes: * * HW sends frames in CAN ID priority order. To preserve FIFO ordering * we submit frames one at a time. */ if (!(devtype->flags & XCAN_FLAG_TX_MAILBOXES) && (devtype->flags & XCAN_FLAG_TXFEMP)) tx_max = min(hw_tx_max, 2); else tx_max = 1; rx_max = hw_rx_max; /* Create a CAN device instance */ ndev = alloc_candev(sizeof(struct xcan_priv), tx_max); if (!ndev) return -ENOMEM; priv = netdev_priv(ndev); priv->dev = &pdev->dev; priv->can.bittiming_const = devtype->bittiming_const; priv->can.do_set_mode = xcan_do_set_mode; priv->can.do_get_berr_counter = xcan_get_berr_counter; priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_BERR_REPORTING; priv->reg_base = addr; priv->tx_max = tx_max; priv->devtype = *devtype; spin_lock_init(&priv->tx_lock); /* Get IRQ for the device */ ndev->irq = platform_get_irq(pdev, 0); ndev->flags |= IFF_ECHO; /* We support local echo */ platform_set_drvdata(pdev, ndev); SET_NETDEV_DEV(ndev, &pdev->dev); ndev->netdev_ops = &xcan_netdev_ops; /* Getting the CAN can_clk info */ priv->can_clk = devm_clk_get(&pdev->dev, "can_clk"); if (IS_ERR(priv->can_clk)) { dev_err(&pdev->dev, "Device clock not found.\n"); ret = PTR_ERR(priv->can_clk); goto err_free; } priv->bus_clk = devm_clk_get(&pdev->dev, devtype->bus_clk_name); if (IS_ERR(priv->bus_clk)) { dev_err(&pdev->dev, "bus clock not found\n"); ret = PTR_ERR(priv->bus_clk); goto err_free; } priv->write_reg = xcan_write_reg_le; priv->read_reg = xcan_read_reg_le; pm_runtime_enable(&pdev->dev); ret = pm_runtime_get_sync(&pdev->dev); if (ret < 0) { netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n", __func__, ret); goto err_pmdisable; } if (priv->read_reg(priv, XCAN_SR_OFFSET) != XCAN_SR_CONFIG_MASK) { priv->write_reg = xcan_write_reg_be; priv->read_reg = xcan_read_reg_be; } priv->can.clock.freq = clk_get_rate(priv->can_clk); netif_napi_add(ndev, &priv->napi, xcan_rx_poll, rx_max); ret = register_candev(ndev); if (ret) { dev_err(&pdev->dev, "fail to register failed (err=%d)\n", ret); goto err_disableclks; } devm_can_led_init(ndev); pm_runtime_put(&pdev->dev); netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx buffers: actual %d, using %d\n", priv->reg_base, ndev->irq, priv->can.clock.freq, hw_tx_max, priv->tx_max); return 0; err_disableclks: pm_runtime_put(priv->dev); err_pmdisable: pm_runtime_disable(&pdev->dev); err_free: free_candev(ndev); err: return ret; } /** * xcan_remove - Unregister the device after releasing the resources * @pdev: Handle to the platform device structure * * This function frees all the resources allocated to the device. * Return: 0 always */ static int xcan_remove(struct platform_device *pdev) { struct net_device *ndev = platform_get_drvdata(pdev); struct xcan_priv *priv = netdev_priv(ndev); unregister_candev(ndev); pm_runtime_disable(&pdev->dev); netif_napi_del(&priv->napi); free_candev(ndev); return 0; } static struct platform_driver xcan_driver = { .probe = xcan_probe, .remove = xcan_remove, .driver = { .name = DRIVER_NAME, .pm = &xcan_dev_pm_ops, .of_match_table = xcan_of_match, }, }; module_platform_driver(xcan_driver); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Xilinx Inc"); MODULE_DESCRIPTION("Xilinx CAN interface");
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