On 03/04/2014 02:20 PM, Kedareswara rao Appana wrote:
> This patch adds xilinx CAN controller support.
> This driver supports both ZYNQ CANPS and Soft IP
> AXI CAN controller.
>
> Signed-off-by: Kedareswara rao Appana <appa...@xilinx.com>
> ---
> This patch is rebased on the 3.14 rc5 kernel.
> Changes for v5:
> - Updated the driver with the review comments.
> - Remove the check for the tx fifo full interrupt condition
> form Tx interrupt routine as we are checking it in the _xmit
> routine.
> - Clearing the txok interrupt in the tx interrupt routine for
> every Tx can frame.
> Changes for v4:
> - Added check for the tx fifo full interrupt condition in
> Tx interrupt routine.
> - Added be iohelper functions.
> - Moved the clock enable/disable to probe/remove because of
> Added big endian support for AXI CAN controller case(reading
> a register during probe for that we need to enable clock).
> Changes for v3:
> - Updated the driver with the review comments.
> - Modified the tranmit logic as per Marc suggestion.
> - Enabling the clock when the interface is up to reduce the
> Power consumption.
> Changes for v2:
> - Updated with the review comments.
> - Removed the unnecessary debug prints.
> - include tx,rx fifo depths in ZYNQ CANPS case also.
> ---
> .../devicetree/bindings/net/can/xilinx_can.txt | 45 +
> drivers/net/can/Kconfig | 7 +
> drivers/net/can/Makefile | 1 +
> drivers/net/can/xilinx_can.c | 1195
> ++++++++++++++++++++
> 4 files changed, 1248 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/net/can/xilinx_can.txt
> create mode 100644 drivers/net/can/xilinx_can.c
>
> diff --git a/Documentation/devicetree/bindings/net/can/xilinx_can.txt
> b/Documentation/devicetree/bindings/net/can/xilinx_can.txt
> new file mode 100644
> index 0000000..0e57103
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/can/xilinx_can.txt
> @@ -0,0 +1,45 @@
> +Xilinx Axi CAN/Zynq CANPS controller Device Tree Bindings
> +---------------------------------------------------------
> +
> +Required properties:
> +- compatible : Should be "xlnx,zynq-can-1.00.a" for Zynq CAN
> + controllers and "xlnx,axi-can-1.00.a" for Axi CAN
> + controllers.
> +- reg : Physical base address and size of the Axi
> CAN/Zynq
> + CANPS registers map.
> +- interrupts : Property with a value describing the interrupt
> + number.
> +- interrupt-parent : Must be core interrupt controller
> +- clock-names : List of input clock names - "ref_clk",
> "aper_clk"
> + (See clock bindings for details. Two clocks are
> + required for Zynq CAN. For Axi CAN
> + case it is one(ref_clk)).
> +- clocks : Clock phandles (see clock bindings for details).
> +- tx-fifo-depth : Can Tx fifo depth.
> +- rx-fifo-depth : Can Rx fifo depth.
> +
> +
> +Example:
> +
> +For Zynq CANPS Dts file:
> + zynq_can_0: zynq-can@e0008000 {
> + compatible = "xlnx,zynq-can-1.00.a";
> + clocks = <&clkc 19>, <&clkc 36>;
> + clock-names = "ref_clk", "aper_clk";
> + reg = <0xe0008000 0x1000>;
> + interrupts = <0 28 4>;
> + interrupt-parent = <&intc>;
> + tx-fifo-depth = <0x40>;
> + rx-fifo-depth = <0x40>;
> + };
> +For Axi CAN Dts file:
> + axi_can_0: axi-can@40000000 {
> + compatible = "xlnx,axi-can-1.00.a";
> + clocks = <&clkc 0>;
> + clock-names = "ref_clk" ;
> + reg = <0x40000000 0x10000>;
> + interrupt-parent = <&intc>;
> + interrupts = <0 59 1>;
> + tx-fifo-depth = <0x40>;
> + rx-fifo-depth = <0x40>;
> + };
> diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
> index 9e7d95d..b180239 100644
> --- a/drivers/net/can/Kconfig
> +++ b/drivers/net/can/Kconfig
> @@ -125,6 +125,13 @@ config CAN_GRCAN
> endian syntheses of the cores would need some modifications on
> the hardware level to work.
>
> +config CAN_XILINXCAN
> + tristate "Xilinx CAN"
> + depends on ARCH_ZYNQ || MICROBLAZEIs Zynq multiarch already? > + ---help--- > + Xilinx CAN driver. This driver supports both soft AXI CAN IP and > + Zynq CANPS IP. > + > source "drivers/net/can/mscan/Kconfig" > > source "drivers/net/can/sja1000/Kconfig" > diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile > index c744039..0b8e11e 100644 > --- a/drivers/net/can/Makefile > +++ b/drivers/net/can/Makefile > @@ -25,5 +25,6 @@ obj-$(CONFIG_CAN_JANZ_ICAN3) += janz-ican3.o > obj-$(CONFIG_CAN_FLEXCAN) += flexcan.o > obj-$(CONFIG_PCH_CAN) += pch_can.o > obj-$(CONFIG_CAN_GRCAN) += grcan.o > +obj-$(CONFIG_CAN_XILINXCAN) += xilinx_can.o > > ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG > diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c > new file mode 100644 > index 0000000..a8552a2 > --- /dev/null > +++ b/drivers/net/can/xilinx_can.c > @@ -0,0 +1,1195 @@ > +/* Xilinx CAN device driver > + * > + * Copyright (C) 2012 - 2014 Xilinx, Inc. > + * Copyright (C) 2009 PetaLogix. All rights reserved. > + * > + * 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. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#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/platform_device.h> > +#include <linux/skbuff.h> > +#include <linux/string.h> > +#include <linux/types.h> > +#include <linux/can/dev.h> > +#include <linux/can/error.h> > +#include <linux/can/led.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 */ > + 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 */ > +}; > + > +/* 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_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_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_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) > + > +/* 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_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_ECHO_SKB_MAX 64 > +#define XCAN_FRAME_MAX_DATA_LEN 8 > +#define XCAN_TIMEOUT (1 * HZ) > + > +/** > + * struct xcan_priv - This definition define CAN driver instance > + * @can: CAN private data structure. > + * @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() > + * @aperclk: Pointer to struct clk > + * @devclk: Pointer to struct clk > + */ > +struct xcan_priv { > + struct can_priv can; > + unsigned int tx_head; > + unsigned int tx_tail; > + u32 tx_max; Please make it an unsigned int, too. > + 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 net_device *dev; > + void __iomem *reg_base; > + unsigned long irq_flags; > + struct clk *aperclk; > + struct clk *devclk; Please rename the clock variables to match the names in the DT. > +}; > + > +/* 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, > +}; > + > +/** > + * 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); > +} > + > +/** > + * 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->can.state = CAN_STATE_STOPPED; I don't think changeing the state makes sense here. You evaluate the priv->can.state in xcan_chip_start(), but you return if this function returns a error. > + > + timeout = jiffies + XCAN_TIMEOUT; > + while (!(priv->read_reg(priv, XCAN_SR_OFFSET) & XCAN_SR_CONFIG_MASK)) { > + if (time_after(jiffies, timeout)) { > + netdev_warn(ndev, "timedout waiting for config mode\n"); > + return -ETIMEDOUT; > + } > + usleep_range(500, 10000); > + } > + > + 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, > + "Cannot set bittiming can is not in config mode\n"); > + return -EPERM; > + } You only call set_bittiming from xcan_chip_start() and go into config mode before. So if this triggers there must be a bug in the driver, you could add "BUG!" to the output. > + > + /* 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) << XCAN_BTR_TS2_SHIFT; > + > + /* Setting Synchronous jump width in BTR Register */ > + btr1 |= (bt->sjw - 1) << XCAN_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 err; > + unsigned long timeout; > + > + /* 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 */ > + priv->write_reg(priv, XCAN_IER_OFFSET, XCAN_INTR_ALL); > + > + /* Check whether it is loopback mode or normal mode */ > + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) > + /* Put device into loopback mode */ > + priv->write_reg(priv, XCAN_MSR_OFFSET, XCAN_MSR_LBACK_MASK); > + else > + /* The device is in normal mode */ > + priv->write_reg(priv, XCAN_MSR_OFFSET, 0); > + > + if (priv->can.state == CAN_STATE_STOPPED) { Your device is in stopped mode, add you go though set_reset_mode() already. > + /* Enable Xilinx CAN */ > + priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK); > + priv->can.state = CAN_STATE_ERROR_ACTIVE; > + timeout = jiffies + XCAN_TIMEOUT; > + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { > + while ((priv->read_reg(priv, XCAN_SR_OFFSET) > + & XCAN_SR_LBACK_MASK) == 0) { > + if (time_after(jiffies, timeout)) { > + netdev_warn(ndev, > + "timedout for loopback mode\n"); > + return -ETIMEDOUT; > + } > + usleep_range(500, 10000); > + } > + } else { > + while ((priv->read_reg(priv, XCAN_SR_OFFSET) > + & XCAN_SR_NORMAL_MASK) == 0) { > + if (time_after(jiffies, timeout)) { > + netdev_warn(ndev, > + "timedout for normal mode\n"); > + return -ETIMEDOUT; > + } > + usleep_range(500, 10000); > + } > + } > + 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"); > + netif_wake_queue(ndev); Don't wake the queue if, chip_start() fails. > + break; > + default: > + ret = -EOPNOTSUPP; > + break; > + } > + > + return ret; > +} > + > +/** > + * 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 > + */ > +static int xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev) > +{ > + 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; > + } > + > + /* 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)); > + > + 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); > + if (!(cf->can_id & CAN_RTR_FLAG)) { > + priv->write_reg(priv, XCAN_TXFIFO_DW1_OFFSET, data[0]); > + /* If the CAN frame is Standard/Extended frame this > + * write triggers tranmission > + */ > + priv->write_reg(priv, XCAN_TXFIFO_DW2_OFFSET, data[1]); > + stats->tx_bytes += cf->can_dlc; > + } > + > + /* Check if the TX buffer is full */ > + if ((priv->tx_head - priv->tx_tail) == priv->tx_max) > + netif_stop_queue(ndev); > + > + return NETDEV_TX_OK; > +} > + > +/** > + * xcan_rx - Is called from CAN isr to complete the received > + * frame processing > + * @ndev: Pointer to net_device structure > + * > + * 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: 0 on success and negative error value on error > + */ > +static int xcan_rx(struct net_device *ndev) > +{ > + 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 (!skb) > + return -ENOMEM; This would only happen under heavy memory preassure, so it's probably better to drop the frame and increase the rx_dropped counter: stats->rx_dropped++; You can make this function return the number of received CAN frames, see flexcan.c. > + > + /* 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; > + > + /* 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_RTR_MASK) > + cf->can_id |= CAN_RTR_FLAG; > + } > + > + if (!(id_xcan & XCAN_IDR_RTR_MASK)) { > + data[0] = priv->read_reg(priv, XCAN_RXFIFO_DW1_OFFSET); > + data[1] = priv->read_reg(priv, XCAN_RXFIFO_DW2_OFFSET); > + > + /* 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]); > + } > + can_led_event(ndev, CAN_LED_EVENT_RX); > + > + netif_receive_skb(skb); > + > + stats->rx_bytes += cf->can_dlc; > + stats->rx_packets++; > + return 0; > +} > + > +/** > + * 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, status; > + > + skb = alloc_can_err_skb(ndev, &cf); > + if (!skb) { > + netdev_err(ndev, "alloc_can_err_skb() failed!\n"); > + return; > + } > + > + err_status = priv->read_reg(priv, XCAN_ESR_OFFSET); > + priv->write_reg(priv, XCAN_ESR_OFFSET, err_status); > + status = priv->read_reg(priv, XCAN_SR_OFFSET); > + > + if (isr & XCAN_IXR_BSOFF_MASK) { > + priv->can.state = CAN_STATE_BUS_OFF; > + cf->can_id |= CAN_ERR_BUSOFF; > + 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); > + } else if ((status & XCAN_SR_ESTAT_MASK) == XCAN_SR_ESTAT_MASK) { > + cf->can_id |= CAN_ERR_CRTL; > + priv->can.state = CAN_STATE_ERROR_PASSIVE; > + priv->can.can_stats.error_passive++; > + cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE | > + CAN_ERR_CRTL_TX_PASSIVE; > + } else if (status & XCAN_SR_ERRWRN_MASK) { > + cf->can_id |= CAN_ERR_CRTL; > + priv->can.state = CAN_STATE_ERROR_WARNING; > + priv->can.can_stats.error_warning++; > + cf->data[1] |= CAN_ERR_CRTL_RX_WARNING | > + CAN_ERR_CRTL_TX_WARNING; > + } > + > + /* Check for Arbitration lost interrupt */ > + if (isr & XCAN_IXR_ARBLST_MASK) { > + cf->can_id |= CAN_ERR_LOSTARB; > + cf->data[0] = CAN_ERR_LOSTARB_UNSPEC; > + priv->can.can_stats.arbitration_lost++; > + } > + > + /* Check for RX FIFO Overflow interrupt */ > + if (isr & XCAN_IXR_RXOFLW_MASK) { > + cf->can_id |= CAN_ERR_CRTL; > + cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW; > + stats->rx_over_errors++; > + stats->rx_errors++; > + priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK); > + } > + > + /* Check for error interrupt */ > + if (isr & XCAN_IXR_ERROR_MASK) { > + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; > + cf->data[2] |= CAN_ERR_PROT_UNSPEC; > + > + /* Check for Ack error interrupt */ > + if (err_status & XCAN_ESR_ACKER_MASK) { > + cf->can_id |= CAN_ERR_ACK; > + cf->data[3] |= CAN_ERR_PROT_LOC_ACK; > + stats->tx_errors++; > + } > + > + /* Check for Bit error interrupt */ > + if (err_status & XCAN_ESR_BERR_MASK) { > + cf->can_id |= CAN_ERR_PROT; > + cf->data[2] = CAN_ERR_PROT_BIT; > + stats->tx_errors++; > + } > + > + /* Check for Stuff error interrupt */ > + if (err_status & XCAN_ESR_STER_MASK) { > + cf->can_id |= CAN_ERR_PROT; > + cf->data[2] = CAN_ERR_PROT_STUFF; > + stats->rx_errors++; > + } > + > + /* Check for Form error interrupt */ > + if (err_status & XCAN_ESR_FMER_MASK) { > + cf->can_id |= CAN_ERR_PROT; > + cf->data[2] = CAN_ERR_PROT_FORM; > + stats->rx_errors++; > + } > + > + /* Check for CRC error interrupt */ > + if (err_status & XCAN_ESR_CRCER_MASK) { > + cf->can_id |= CAN_ERR_PROT; > + cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ | > + CAN_ERR_PROT_LOC_CRC_DEL; > + stats->rx_errors++; > + } > + priv->can.can_stats.bus_error++; > + } > + > + netif_rx(skb); > + stats->rx_packets++; > + stats->rx_bytes += cf->can_dlc; > + > + 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_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 isr, 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); > + if (xcan_rx(ndev) < 0) > + return work_done; You should not leave the napi function like this, you are not allowed to skip the if (work_done < quota) {...} part. > + work_done++; I think the flexcan does it better: work_done += xcan_rx(ndev); > + } else { > + 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); > + } > + > + if (work_done < quota) { > + napi_complete(napi); > + ier = priv->read_reg(priv, XCAN_IER_OFFSET); > + ier |= (XCAN_IXR_RXOK_MASK | XCAN_IXR_RXNEMP_MASK); > + 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; > + > + while (priv->tx_head - priv->tx_tail > 0) { > + priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK); > + if (!(isr & XCAN_IXR_TXOK_MASK)) > + break; > + can_get_echo_skb(ndev, priv->tx_tail % > + priv->tx_max); > + priv->tx_tail++; > + stats->tx_packets++; > + can_led_event(ndev, CAN_LED_EVENT_TX); > + isr = priv->read_reg(priv, XCAN_ISR_OFFSET); > + } > + netif_wake_queue(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; > + > + /* Get the interrupt status from Xilinx CAN */ > + isr = priv->read_reg(priv, XCAN_ISR_OFFSET); > + if (!isr) > + return IRQ_NONE; > + > + netdev_dbg(ndev, "%s: isr:#x%08x, err:#x%08x\n", __func__, > + isr, priv->read_reg(priv, XCAN_ESR_OFFSET)); Please remove this debug output. > + /* 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) { > + priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK); I think this write is now completely inside tx_interrupt()? > + 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)); > + 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)) { > + ier = priv->read_reg(priv, XCAN_IER_OFFSET); > + ier &= ~(XCAN_IXR_RXNEMP_MASK | XCAN_IXR_RXOK_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); > + 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); > + 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 = 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; > + } > + > + ret = clk_prepare_enable(priv->devclk); > + if (ret) { > + netdev_err(ndev, "unable to enable device clock\n"); > + goto err; > + } > + > + ret = clk_prepare_enable(priv->aperclk); > + if (ret) { > + netdev_err(ndev, "unable to enable aper clock\n"); > + goto err_aperclk; > + } > + > + /* Set chip into reset mode */ > + ret = set_reset_mode(ndev); > + if (ret < 0) { > + netdev_err(ndev, "mode resetting failed failed!\n"); > + goto err_devclk; > + } > + > + /* Common open */ > + ret = open_candev(ndev); > + if (ret) > + goto err_devclk; > + > + ret = xcan_chip_start(ndev); > + if (ret < 0) { > + netdev_err(ndev, "xcan_chip_start failed!\n"); > + goto err_devclk; > + } > + > + can_led_event(ndev, CAN_LED_EVENT_OPEN); > + napi_enable(&priv->napi); > + netif_start_queue(ndev); > + > + return 0; > + > +err_aperclk: > + free_irq(ndev->irq, ndev); > + clk_disable_unprepare(priv->devclk); > +err_devclk: > + free_irq(ndev->irq, ndev); > + clk_disable_unprepare(priv->devclk); > + clk_disable_unprepare(priv->aperclk); Have a look at your cleanup code, double free irq()? double disable the dev_clk, this looks broken? > +err: > + 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); > + clk_disable_unprepare(priv->aperclk); > + clk_disable_unprepare(priv->devclk); > + free_irq(ndev->irq, ndev); > + close_candev(ndev); > + > + can_led_event(ndev, CAN_LED_EVENT_STOP); > + > + 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 always > + */ > +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 = clk_prepare_enable(priv->devclk); > + if (ret) > + goto err; > + > + ret = clk_prepare_enable(priv->aperclk); > + if (ret) > + goto err_clk; > + > + 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); > + > + clk_disable_unprepare(priv->aperclk); > + clk_disable_unprepare(priv->devclk); > + > + return 0; > + > +err_clk: > + clk_disable_unprepare(priv->devclk); > +err: > + return ret; > +} > + > +static const struct net_device_ops xcan_netdev_ops = { > + .ndo_open = xcan_open, > + .ndo_stop = xcan_close, > + .ndo_start_xmit = xcan_start_xmit, > +}; > + > +#ifdef CONFIG_PM_SLEEP please remove the ifdef... > +/** > + * xcan_suspend - Suspend method for the driver > + * @_dev: Address of the platform_device structure > + * > + * Put the driver into low power mode. > + * Return: 0 always > + */ > +static int xcan_suspend(struct device *_dev) ...add __maybe_unused instead. > +{ > + struct platform_device *pdev = container_of(_dev, > + struct platform_device, dev); dev_get_drvdata(device); > + struct net_device *ndev = platform_get_drvdata(pdev); > + 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(priv->aperclk); > + clk_disable(priv->devclk); > + > + return 0; > +} > + > +/** > + * xcan_resume - Resume from suspend > + * @dev: Address of the platformdevice structure > + * > + * Resume operation after suspend. > + * Return: 0 on success and failure value on error > + */ > +static int xcan_resume(struct device *dev) dito > +{ > + struct platform_device *pdev = container_of(dev, > + struct platform_device, dev); dito > + struct net_device *ndev = platform_get_drvdata(pdev); > + struct xcan_priv *priv = netdev_priv(ndev); > + int ret; > + > + ret = clk_enable(priv->aperclk); > + if (ret) { > + dev_err(dev, "Cannot enable clock.\n"); > + return ret; > + } > + ret = clk_enable(priv->devclk); > + if (ret) { > + dev_err(dev, "Cannot enable clock.\n"); > + clk_disable_unprepare(priv->aperclk); > + return ret; > + } > + > + priv->write_reg(priv, XCAN_MSR_OFFSET, 0); > + priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK); > + priv->can.state = CAN_STATE_ERROR_ACTIVE; > + > + if (netif_running(ndev)) { > + netif_device_attach(ndev); > + netif_start_queue(ndev); > + } > + > + return 0; > +} > +#endif > + > +static SIMPLE_DEV_PM_OPS(xcan_dev_pm_ops, xcan_suspend, xcan_resume); > + > +/** > + * 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; > + int ret, rx_max; > + > + /* Create a CAN device instance */ > + ndev = alloc_candev(sizeof(struct xcan_priv), XCAN_ECHO_SKB_MAX); Can you rearange your code, so that you use tx-fifo-depth instead of a hard coded value? > + if (!ndev) > + return -ENOMEM; > + > + priv = netdev_priv(ndev); > + priv->dev = ndev; > + priv->can.bittiming_const = &xcan_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; > + > + /* 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; > + > + /* Get the virtual base address for the device */ > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + priv->reg_base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(priv->reg_base)) { > + ret = PTR_ERR(priv->reg_base); > + goto err_free; > + } > + > + ret = of_property_read_u32(pdev->dev.of_node, "tx-fifo-depth", > + &priv->tx_max); > + if (ret < 0) > + goto err_free; > + > + ret = of_property_read_u32(pdev->dev.of_node, "rx-fifo-depth", &rx_max); > + if (ret < 0) > + goto err_free; > + > + /* Getting the CAN devclk info */ > + priv->devclk = devm_clk_get(&pdev->dev, "ref_clk"); > + if (IS_ERR(priv->devclk)) { > + dev_err(&pdev->dev, "Device clock not found.\n"); > + ret = PTR_ERR(priv->devclk); > + goto err_free; > + } > + > + /* Check for type of CAN device */ > + if (of_device_is_compatible(pdev->dev.of_node, > + "xlnx,zynq-can-1.00.a")) { > + priv->aperclk = devm_clk_get(&pdev->dev, "aper_clk"); > + if (IS_ERR(priv->aperclk)) { > + dev_err(&pdev->dev, "aper clock not found\n"); > + ret = PTR_ERR(priv->aperclk); > + goto err_free; > + } > + } else { > + priv->aperclk = priv->devclk; > + } > + > + ret = clk_prepare_enable(priv->devclk); > + if (ret) { > + dev_err(&pdev->dev, "unable to enable device clock\n"); > + goto err_free; > + } > + > + ret = clk_prepare_enable(priv->aperclk); > + if (ret) { > + dev_err(&pdev->dev, "unable to enable aper clock\n"); > + goto err_unprepar_disabledev; > + } > + > + priv->write_reg = xcan_write_reg_le; > + priv->read_reg = xcan_read_reg_le; > + > + 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->devclk); > + > + 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_unprepar_disableaper; > + } > + > + devm_can_led_init(ndev); > + clk_disable_unprepare(priv->aperclk); > + clk_disable_unprepare(priv->devclk); > + 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); > + > + return 0; > + > +err_unprepar_disableaper: typo ^^^^ ^^^^ can you add a _ err_unprepare_disable_aper: > + clk_disable_unprepare(priv->aperclk); > +err_unprepar_disabledev: > + clk_disable_unprepare(priv->devclk); > +err_free: > + free_candev(ndev); > + > + 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); > + > + if (set_reset_mode(ndev) < 0) > + netdev_err(ndev, "mode resetting failed!\n"); > + > + unregister_candev(ndev); > + netif_napi_del(&priv->napi); > + free_candev(ndev); > + > + return 0; > +} > + > +/* Match table for OF platform binding */ > +static struct of_device_id xcan_of_match[] = { > + { .compatible = "xlnx,zynq-can-1.00.a", }, > + { .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, > + .driver = { > + .owner = THIS_MODULE, > + .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"); > Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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