diff options
Diffstat (limited to 'drivers/net/can/xilinx_can.c')
| -rw-r--r-- | drivers/net/can/xilinx_can.c | 784 |
1 files changed, 596 insertions, 188 deletions
diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c index 89aec07c225f..045f0845e665 100644 --- a/drivers/net/can/xilinx_can.c +++ b/drivers/net/can/xilinx_can.c @@ -2,6 +2,7 @@ * * 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. @@ -25,8 +26,10 @@ #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> @@ -48,16 +51,34 @@ enum xcan_reg { XCAN_ISR_OFFSET = 0x1C, /* Interrupt status */ XCAN_IER_OFFSET = 0x20, /* Interrupt enable */ XCAN_ICR_OFFSET = 0x24, /* Interrupt clear */ - XCAN_TXFIFO_ID_OFFSET = 0x30,/* TX FIFO ID */ - XCAN_TXFIFO_DLC_OFFSET = 0x34, /* TX FIFO DLC */ - XCAN_TXFIFO_DW1_OFFSET = 0x38, /* TX FIFO Data Word 1 */ - XCAN_TXFIFO_DW2_OFFSET = 0x3C, /* TX FIFO Data Word 2 */ - XCAN_RXFIFO_ID_OFFSET = 0x50, /* RX FIFO ID */ - XCAN_RXFIFO_DLC_OFFSET = 0x54, /* RX FIFO DLC */ - XCAN_RXFIFO_DW1_OFFSET = 0x58, /* RX FIFO Data Word 1 */ - XCAN_RXFIFO_DW2_OFFSET = 0x5C, /* RX FIFO Data Word 2 */ + + /* 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 */ @@ -67,6 +88,9 @@ enum xcan_reg { #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 */ @@ -80,6 +104,7 @@ enum xcan_reg { #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 */ @@ -97,15 +122,15 @@ enum xcan_reg { #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_INTR_ALL (XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK |\ - XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK | \ - XCAN_IXR_RXNEMP_MASK | XCAN_IXR_ERROR_MASK | \ - XCAN_IXR_ARBLST_MASK | XCAN_IXR_RXOK_MASK) +#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 */ @@ -115,9 +140,31 @@ enum xcan_reg { #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 @@ -129,9 +176,11 @@ enum xcan_reg { * @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; @@ -144,6 +193,7 @@ struct xcan_priv { 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 */ @@ -159,6 +209,18 @@ static const struct can_bittiming_const xcan_bittiming_const = { .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 @@ -214,6 +276,23 @@ static u32 xcan_read_reg_be(const struct xcan_priv *priv, enum xcan_reg 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 * @@ -238,6 +317,10 @@ static int set_reset_mode(struct net_device *ndev) usleep_range(500, 10000); } + /* reset clears FIFOs */ + priv->tx_head = 0; + priv->tx_tail = 0; + return 0; } @@ -273,10 +356,10 @@ static int xcan_set_bittiming(struct net_device *ndev) btr1 = (bt->prop_seg + bt->phase_seg1 - 1); /* Setting Time Segment 2 in BTR Register */ - btr1 |= (bt->phase_seg2 - 1) << XCAN_BTR_TS2_SHIFT; + btr1 |= (bt->phase_seg2 - 1) << priv->devtype.btr_ts2_shift; /* Setting Synchronous jump width in BTR Register */ - btr1 |= (bt->sjw - 1) << XCAN_BTR_SJW_SHIFT; + 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); @@ -304,6 +387,7 @@ static int xcan_chip_start(struct net_device *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); @@ -315,7 +399,15 @@ static int xcan_chip_start(struct net_device *ndev) return err; /* Enable interrupts */ - priv->write_reg(priv, XCAN_IER_OFFSET, XCAN_INTR_ALL); + 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) { @@ -326,6 +418,12 @@ static int xcan_chip_start(struct net_device *ndev) 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); @@ -376,33 +474,15 @@ static int xcan_do_set_mode(struct net_device *ndev, enum can_mode mode) } /** - * 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. This - * function uses the next available free txbuff and populates their fields to - * start the transmission. - * - * Return: 0 on success and failure value on error + * 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 int xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev) +static void xcan_write_frame(struct xcan_priv *priv, struct sk_buff *skb, + int frame_offset) { - struct xcan_priv *priv = netdev_priv(ndev); - struct net_device_stats *stats = &ndev->stats; - struct can_frame *cf = (struct can_frame *)skb->data; u32 id, dlc, data[2] = {0, 0}; - - if (can_dropped_invalid_skb(ndev, skb)) - return NETDEV_TX_OK; - - /* Check if the TX buffer is full */ - if (unlikely(priv->read_reg(priv, XCAN_SR_OFFSET) & - XCAN_SR_TXFLL_MASK)) { - netif_stop_queue(ndev); - netdev_err(ndev, "BUG!, TX FIFO full when queue awake!\n"); - return NETDEV_TX_BUSY; - } + struct can_frame *cf = (struct can_frame *)skb->data; /* Watch carefully on the bit sequence */ if (cf->can_id & CAN_EFF_FLAG) { @@ -438,26 +518,119 @@ static int xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev) if (cf->can_dlc > 4) data[1] = be32_to_cpup((__be32 *)(cf->data + 4)); - can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max); - priv->tx_head++; - - /* Write the Frame to Xilinx CAN TX FIFO */ - priv->write_reg(priv, XCAN_TXFIFO_ID_OFFSET, id); - /* If the CAN frame is RTR frame this write triggers tranmission */ - priv->write_reg(priv, XCAN_TXFIFO_DLC_OFFSET, dlc); + 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_TXFIFO_DW1_OFFSET, data[0]); + priv->write_reg(priv, XCAN_FRAME_DW1_OFFSET(frame_offset), + data[0]); /* If the CAN frame is Standard/Extended frame this - * write triggers tranmission + * write triggers transmission (not on CAN FD) */ - priv->write_reg(priv, XCAN_TXFIFO_DW2_OFFSET, data[1]); - stats->tx_bytes += cf->can_dlc; + 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; } @@ -465,13 +638,14 @@ static int xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev) * 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) +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; @@ -486,9 +660,9 @@ static int xcan_rx(struct net_device *ndev) } /* Read a frame from Xilinx zynq CANPS */ - id_xcan = priv->read_reg(priv, XCAN_RXFIFO_ID_OFFSET); - dlc = priv->read_reg(priv, XCAN_RXFIFO_DLC_OFFSET) >> - XCAN_DLCR_DLC_SHIFT; + 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); @@ -511,8 +685,8 @@ static int xcan_rx(struct net_device *ndev) } /* DW1/DW2 must always be read to remove message from RXFIFO */ - data[0] = priv->read_reg(priv, XCAN_RXFIFO_DW1_OFFSET); - data[1] = priv->read_reg(priv, XCAN_RXFIFO_DW2_OFFSET); + 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 */ @@ -530,6 +704,103 @@ static int xcan_rx(struct net_device *ndev) } /** + * 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 @@ -544,16 +815,12 @@ static void xcan_err_interrupt(struct net_device *ndev, u32 isr) struct net_device_stats *stats = &ndev->stats; struct can_frame *cf; struct sk_buff *skb; - u32 err_status, status, txerr = 0, rxerr = 0; + 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); - txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK; - rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) & - XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT); - status = priv->read_reg(priv, XCAN_SR_OFFSET); if (isr & XCAN_IXR_BSOFF_MASK) { priv->can.state = CAN_STATE_BUS_OFF; @@ -563,28 +830,11 @@ static void xcan_err_interrupt(struct net_device *ndev, u32 isr) can_bus_off(ndev); if (skb) cf->can_id |= CAN_ERR_BUSOFF; - } else if ((status & XCAN_SR_ESTAT_MASK) == XCAN_SR_ESTAT_MASK) { - priv->can.state = CAN_STATE_ERROR_PASSIVE; - priv->can.can_stats.error_passive++; - if (skb) { - cf->can_id |= CAN_ERR_CRTL; - cf->data[1] = (rxerr > 127) ? - CAN_ERR_CRTL_RX_PASSIVE : - CAN_ERR_CRTL_TX_PASSIVE; - cf->data[6] = txerr; - cf->data[7] = rxerr; - } - } else if (status & XCAN_SR_ERRWRN_MASK) { - priv->can.state = CAN_STATE_ERROR_WARNING; - priv->can.can_stats.error_warning++; - if (skb) { - cf->can_id |= CAN_ERR_CRTL; - cf->data[1] |= (txerr > rxerr) ? - CAN_ERR_CRTL_TX_WARNING : - CAN_ERR_CRTL_RX_WARNING; - cf->data[6] = txerr; - cf->data[7] = rxerr; - } + } 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 */ @@ -600,13 +850,23 @@ static void xcan_err_interrupt(struct net_device *ndev, u32 isr) if (isr & XCAN_IXR_RXOFLW_MASK) { stats->rx_over_errors++; stats->rx_errors++; - priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK); 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) @@ -691,6 +951,44 @@ static void xcan_state_interrupt(struct net_device *ndev, u32 isr) } /** + * 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. @@ -704,31 +1002,35 @@ 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 isr, ier; + u32 ier; int work_done = 0; - - isr = priv->read_reg(priv, XCAN_ISR_OFFSET); - while ((isr & XCAN_IXR_RXNEMP_MASK) && (work_done < quota)) { - if (isr & XCAN_IXR_RXOK_MASK) { - priv->write_reg(priv, XCAN_ICR_OFFSET, - XCAN_IXR_RXOK_MASK); - work_done += xcan_rx(ndev); - } else { + 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); - break; - } - priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_RXNEMP_MASK); - isr = priv->read_reg(priv, XCAN_ISR_OFFSET); + XCAN_IXR_RXNEMP_MASK); } - if (work_done) + 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_IXR_RXOK_MASK | XCAN_IXR_RXNEMP_MASK); + ier |= xcan_rx_int_mask(priv); priv->write_reg(priv, XCAN_IER_OFFSET, ier); } return work_done; @@ -743,18 +1045,71 @@ 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; - while ((priv->tx_head - priv->tx_tail > 0) && - (isr & XCAN_IXR_TXOK_MASK)) { + 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); - can_get_echo_skb(ndev, priv->tx_tail % - priv->tx_max); + 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++; - isr = priv->read_reg(priv, XCAN_ISR_OFFSET); } - can_led_event(ndev, CAN_LED_EVENT_TX); + 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); } /** @@ -773,6 +1128,8 @@ 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); @@ -791,18 +1148,18 @@ static irqreturn_t xcan_interrupt(int irq, void *dev_id) xcan_tx_interrupt(ndev, isr); /* Check for the type of error interrupt and Processing it */ - if (isr & (XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK | - XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK)) { - priv->write_reg(priv, XCAN_ICR_OFFSET, (XCAN_IXR_ERROR_MASK | - XCAN_IXR_RXOFLW_MASK | XCAN_IXR_BSOFF_MASK | - XCAN_IXR_ARBLST_MASK)); + 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 & (XCAN_IXR_RXNEMP_MASK | XCAN_IXR_RXOK_MASK)) { + if (isr & rx_int_mask) { ier = priv->read_reg(priv, XCAN_IER_OFFSET); - ier &= ~(XCAN_IXR_RXNEMP_MASK | XCAN_IXR_RXOK_MASK); + ier &= ~rx_int_mask; priv->write_reg(priv, XCAN_IER_OFFSET, ier); napi_schedule(&priv->napi); } @@ -819,13 +1176,9 @@ static irqreturn_t xcan_interrupt(int irq, void *dev_id) static void xcan_chip_stop(struct net_device *ndev) { struct xcan_priv *priv = netdev_priv(ndev); - u32 ier; /* Disable interrupts and leave the can in configuration mode */ - ier = priv->read_reg(priv, XCAN_IER_OFFSET); - ier &= ~XCAN_INTR_ALL; - priv->write_reg(priv, XCAN_IER_OFFSET, ier); - priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK); + set_reset_mode(ndev); priv->can.state = CAN_STATE_STOPPED; } @@ -958,10 +1311,15 @@ static const struct net_device_ops xcan_netdev_ops = { */ static int __maybe_unused xcan_suspend(struct device *dev) { - if (!device_may_wakeup(dev)) - return pm_runtime_force_suspend(dev); + struct net_device *ndev = dev_get_drvdata(dev); - return 0; + if (netif_running(ndev)) { + netif_stop_queue(ndev); + netif_device_detach(ndev); + xcan_chip_stop(ndev); + } + + return pm_runtime_force_suspend(dev); } /** @@ -973,11 +1331,27 @@ static int __maybe_unused xcan_suspend(struct device *dev) */ static int __maybe_unused xcan_resume(struct device *dev) { - if (!device_may_wakeup(dev)) - return pm_runtime_force_resume(dev); + struct net_device *ndev = dev_get_drvdata(dev); + int ret; - return 0; + 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; } /** @@ -992,14 +1366,6 @@ 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); - if (netif_running(ndev)) { - netif_stop_queue(ndev); - netif_device_detach(ndev); - } - - priv->write_reg(priv, XCAN_MSR_OFFSET, XCAN_MSR_SLEEP_MASK); - priv->can.state = CAN_STATE_SLEEPING; - clk_disable_unprepare(priv->bus_clk); clk_disable_unprepare(priv->can_clk); @@ -1018,7 +1384,6 @@ 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; - u32 isr, status; ret = clk_prepare_enable(priv->bus_clk); if (ret) { @@ -1032,27 +1397,6 @@ static int __maybe_unused xcan_runtime_resume(struct device *dev) return ret; } - priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK); - isr = priv->read_reg(priv, XCAN_ISR_OFFSET); - status = priv->read_reg(priv, XCAN_SR_OFFSET); - - if (netif_running(ndev)) { - if (isr & XCAN_IXR_BSOFF_MASK) { - priv->can.state = CAN_STATE_BUS_OFF; - priv->write_reg(priv, XCAN_SRR_OFFSET, - XCAN_SRR_RESET_MASK); - } else if ((status & XCAN_SR_ESTAT_MASK) == - XCAN_SR_ESTAT_MASK) { - priv->can.state = CAN_STATE_ERROR_PASSIVE; - } else if (status & XCAN_SR_ERRWRN_MASK) { - priv->can.state = CAN_STATE_ERROR_WARNING; - } else { - priv->can.state = CAN_STATE_ERROR_ACTIVE; - } - netif_device_attach(ndev); - netif_start_queue(ndev); - } - return 0; } @@ -1061,6 +1405,40 @@ static const struct dev_pm_ops xcan_dev_pm_ops = { 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 @@ -1075,8 +1453,13 @@ 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, rx_max, tx_max; + 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); @@ -1086,13 +1469,54 @@ static int xcan_probe(struct platform_device *pdev) goto err; } - ret = of_property_read_u32(pdev->dev.of_node, "tx-fifo-depth", &tx_max); - if (ret < 0) + 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", &rx_max); - if (ret < 0) + 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); @@ -1101,13 +1525,15 @@ static int xcan_probe(struct platform_device *pdev) priv = netdev_priv(ndev); priv->dev = &pdev->dev; - priv->can.bittiming_const = &xcan_bittiming_const; + 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); @@ -1124,22 +1550,12 @@ static int xcan_probe(struct platform_device *pdev) ret = PTR_ERR(priv->can_clk); goto err_free; } - /* Check for type of CAN device */ - if (of_device_is_compatible(pdev->dev.of_node, - "xlnx,zynq-can-1.0")) { - priv->bus_clk = devm_clk_get(&pdev->dev, "pclk"); - if (IS_ERR(priv->bus_clk)) { - dev_err(&pdev->dev, "bus clock not found\n"); - ret = PTR_ERR(priv->bus_clk); - goto err_free; - } - } else { - priv->bus_clk = devm_clk_get(&pdev->dev, "s_axi_aclk"); - 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->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; @@ -1172,9 +1588,9 @@ static int xcan_probe(struct platform_device *pdev) pm_runtime_put(&pdev->dev); - netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx fifo depth:%d\n", - priv->reg_base, ndev->irq, priv->can.clock.freq, - priv->tx_max); + 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; @@ -1208,14 +1624,6 @@ static int xcan_remove(struct platform_device *pdev) return 0; } -/* Match table for OF platform binding */ -static const struct of_device_id xcan_of_match[] = { - { .compatible = "xlnx,zynq-can-1.0", }, - { .compatible = "xlnx,axi-can-1.00.a", }, - { /* end of list */ }, -}; -MODULE_DEVICE_TABLE(of, xcan_of_match); - static struct platform_driver xcan_driver = { .probe = xcan_probe, .remove = xcan_remove, |