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Message-Id: <201402210222.50283.sergei.shtylyov@cogentembedded.com>
Date: Fri, 21 Feb 2014 02:22:49 +0300
From: Sergei Shtylyov <sergei.shtylyov@...entembedded.com>
To: netdev@...r.kernel.org, wg@...ndegger.com, mkl@...gutronix.de,
linux-can@...r.kernel.org
Cc: linux-sh@...r.kernel.org, vksavl@...il.com
Subject: [PATCH v7] can: add Renesas R-Car CAN driver
Add support for the CAN controller found in Renesas R-Car SoCs.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@...entembedded.com>
---
The patch is against the 'linux-can-next.git' repo.
Changes in version 7:
- changed TX algorithm to use mode in which TX FIFO interrupt is generated every
time transmission completes, thus changed 3 fields of 'struct rcar_can_priv',
removed #define RCAR_CAN_MIER1_TXFIT, and renamed #define RCAR_CAN_N_ECHO_SKB
to RCAR_CAN_FIFO_DEPTH decreasing its value to 4;
- got the shifts in the BCR (24-bit register) field macros into the correct
range;
- removed extra write to CLKR in rcar_can_set_bittiming(), adding comment about
the register access peculiarities;
- restructured the loops polling STR.RSTST bit to avoid checkpatch.pl's errors;
- fixed heading comment format to avoid checkpatch.pl's warning.
Changes in version 6:
- removed '__packed' from 'struct rcar_can_mbox_regs' and 'struct
rcar_can_regs';
- added counter to the loops polling STR.RSTST bit and converted them to use
*for*;
- added error check and message in case of clk_[prepare_]enable() failure;
- fixed *goto* and error message in case of open_candev() failure;
- clarified check and added comment for calling netif_stop_queue();
- moved comments in theframe format decoding code to the right and so got rid of
the braces;
- removed internal *for* loop from rcar_can_rx_poll(). converting *while* loop
to *for*;
- converted 0xFF to lowercase;
- removed type cast in the 'ndev' variable initializer in rcar_can_interrupt();
- converted CLKR_* #define's to *enum*, used it in the platform data;
- changed the type of 'i' variable in tx_failure_cleanup() to *int*;
- fixed register_candev() error message to print the error code;
- added parens in the alloc_candev() error message;
- indented with tab the value of #define RCAR_CAN_NAPI_WEIGHT.
Changes in version 5:
- removed the code specific to the mailbox mode handling and added the code
for the FIFO mode, dropping support for CAN_CTRLMODE_ONE_SHOT;
- stop accumulating errors in the byte 1 of an error frame;
- added #define RCAR_CAN_CTLR_CANM for CTLR.CANM field, added 'CANM_' infix to
all its values;
- replaced ~RCAR_CAN_CTLR_CANM_FORCE_RESET with ~RCAR_CAN_CTLR_CANM;
- added polling for the CAN reset status bit when going from/to CAN reset.
Changes in version 4:
- added 'RCAR_CAN_' prefix to all #define's;
- replaced all BIT(N) invocations with (1 << N) which allowed to remove casts
to 'u8';
- called rcar_can_set_bittiming() from rcar_can_start() again and stopped
registering it as do_set_bittiming() method which allowed to remove clock
API calls and control register writes from this function and make it *void*;
- added #define RCAR_CAN_CTLR_IDFM for more clarity;
- clarified comment to #define RCAR_CAN_IER_TXMIE;
- did some whitespace cleanups.
Changes in version 3:
- replaced the register #define's with 'struct rcar_can_regs' fields, replaced
rcar_can_{read|write}[bwl]() with mere {read|write}[bwl]();
- removed hardware bus-off recovery support which allowed to also remove
rcar_can_start() prototype;
- added RX/TX error count to error data frame for error warning/passive;
- moved TX completion interrupt handling into separate function;
- added '__packed' to 'struct rcar_can_mbox_regs' and 'struct rcar_can_regs';
- removed unneeded type cast in the probe() method.
Changes in version 2:
- added function to clean up TX mailboxes after bus error and bus-off;
- added module parameter to enable hardware recovery from bus-off, added handler
for the bus-off recovery interrupt, and set the control register according to
the parameter value and the restart timer setting in rcar_can_start();
- changed the way CAN_ERR_CRTL_[RT]X_{PASSIVE|WARNING} flags are set to a more
realistic one;
- replaced MBX_* macros and rcar_can_mbx_{read|write}[bl]() functions with
'struct rcar_can_mbox_regs', 'struct rcar_can_regs', and {read|write}[bl](),
replaced 'reg_base' field of 'struct rcar_can_priv' with 'struct rcar_can_regs
__iomem *regs';
- added 'ier' field to 'struct rcar_can_priv' to cache the current value of the
interrupt enable register;
- added a check for enabled interrupts on entry to rcar_can_interrupt();
- limited transmit mailbox search loop in rcar_can_interrupt();
- decoupled TX byte count increment from can_get_echo_skb() call;
- removed netif_queue_stopped() call from rcar_can_interrupt();
- added clk_prepare_enable()/clk_disable_unprepare() to ndo_{open|close}(),
do_set_bittiming(), and do_get_berr_counter() methods, removed clk_enable()
call from the probe() method and clk_disable() call from the remove() method;
- allowed rcar_can_set_bittiming() to be called when the device is closed and
remove explicit call to it from rcar_can_start();
- switched to using mailbox number priority transmit mode, and switched to the
sequential mailbox use in ndo_start_xmit() method;
- stopped reading the message control registers in ndo_start_xmit() method;
- avoided returning NETDEV_TX_BUSY from ndo_start_xmit() method;
- stopped reading data when RTR bit is set in the CAN frame;
- made 'num_pkts' variable *int* and moved its check to the *while* condition in
rcar_can_rx_poll();
- used dev_get_platdata() in the probe() method;
- enabled bus error interrupt only if CAN_CTRLMODE_BERR_REPORTING flag is set;
- started reporting CAN_CTRLMODE_BERR_REPORTING support and stopped reporting
CAN_CTRLMODE_3_SAMPLES support;
- set CAN_ERR_ACK flag on ACK error;
- switched to incrementing bus error counter only once per bus error interrupt;
- started switching to CAN sleep mode in rcar_can_stop() and stopped switching
to it in the remove() method;
- removed netdev_err() calls on allocation failure in rcar_can_error() and
rcar_can_rx_pkt();
- removed "CANi" from the register offset macro comments.
drivers/net/can/Kconfig | 9
drivers/net/can/Makefile | 1
drivers/net/can/rcar_can.c | 858 ++++++++++++++++++++++++++++++++++
include/linux/can/platform/rcar_can.h | 17
4 files changed, 885 insertions(+)
Index: linux-can-next/drivers/net/can/Kconfig
===================================================================
--- linux-can-next.orig/drivers/net/can/Kconfig
+++ linux-can-next/drivers/net/can/Kconfig
@@ -125,6 +125,15 @@ config CAN_GRCAN
endian syntheses of the cores would need some modifications on
the hardware level to work.
+config CAN_RCAR
+ tristate "Renesas R-Car CAN controller"
+ ---help---
+ Say Y here if you want to use CAN controller found on Renesas R-Car
+ SoCs.
+
+ To compile this driver as a module, choose M here: the module will
+ be called rcar_can.
+
source "drivers/net/can/mscan/Kconfig"
source "drivers/net/can/sja1000/Kconfig"
Index: linux-can-next/drivers/net/can/Makefile
===================================================================
--- linux-can-next.orig/drivers/net/can/Makefile
+++ linux-can-next/drivers/net/can/Makefile
@@ -25,5 +25,6 @@ obj-$(CONFIG_CAN_JANZ_ICAN3) += janz-ica
obj-$(CONFIG_CAN_FLEXCAN) += flexcan.o
obj-$(CONFIG_PCH_CAN) += pch_can.o
obj-$(CONFIG_CAN_GRCAN) += grcan.o
+obj-$(CONFIG_CAN_RCAR) += rcar_can.o
ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
Index: linux-can-next/drivers/net/can/rcar_can.c
===================================================================
--- /dev/null
+++ linux-can-next/drivers/net/can/rcar_can.c
@@ -0,0 +1,858 @@
+/* Renesas R-Car CAN device driver
+ *
+ * Copyright (C) 2013 Cogent Embedded, Inc. <source@...entembedded.com>
+ * Copyright (C) 2013 Renesas Solutions Corp.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/platform_device.h>
+#include <linux/can/led.h>
+#include <linux/can/dev.h>
+#include <linux/clk.h>
+#include <linux/can/platform/rcar_can.h>
+
+#define RCAR_CAN_DRV_NAME "rcar_can"
+
+/* Mailbox configuration:
+ * mailbox 60 - 63 - Rx FIFO mailboxes
+ * mailbox 56 - 59 - Tx FIFO mailboxes
+ * non-FIFO mailboxes are not used
+ */
+#define RCAR_CAN_N_MBX 64 /* Number of mailboxes in non-FIFO mode */
+#define RCAR_CAN_RX_FIFO_MBX 60 /* Mailbox - window to Rx FIFO */
+#define RCAR_CAN_TX_FIFO_MBX 56 /* Mailbox - window to Tx FIFO */
+#define RCAR_CAN_FIFO_DEPTH 4
+
+/* Mailbox registers structure */
+struct rcar_can_mbox_regs {
+ u32 id; /* IDE and RTR bits, SID and EID */
+ u8 stub; /* Not used */
+ u8 dlc; /* Data Length Code - bits [0..3] */
+ u8 data[8]; /* Data Bytes */
+ u8 tsh; /* Time Stamp Higher Byte */
+ u8 tsl; /* Time Stamp Lower Byte */
+};
+
+struct rcar_can_regs {
+ struct rcar_can_mbox_regs mb[RCAR_CAN_N_MBX]; /* Mailbox registers */
+ u32 mkr_2_9[8]; /* Mask Registers 2-9 */
+ u32 fidcr[2]; /* FIFO Received ID Compare Register */
+ u32 mkivlr1; /* Mask Invalid Register 1 */
+ u32 mier1; /* Mailbox Interrupt Enable Register 1 */
+ u32 mkr_0_1[2]; /* Mask Registers 0-1 */
+ u32 mkivlr0; /* Mask Invalid Register 0*/
+ u32 mier0; /* Mailbox Interrupt Enable Register 0 */
+ u8 pad_440[0x3c0];
+ u8 mctl[64]; /* Message Control Registers */
+ u16 ctlr; /* Control Register */
+ u16 str; /* Status register */
+ u8 bcr[3]; /* Bit Configuration Register */
+ u8 clkr; /* Clock Select Register */
+ u8 rfcr; /* Receive FIFO Control Register */
+ u8 rfpcr; /* Receive FIFO Pointer Control Register */
+ u8 tfcr; /* Transmit FIFO Control Register */
+ u8 tfpcr; /* Transmit FIFO Pointer Control Register */
+ u8 eier; /* Error Interrupt Enable Register */
+ u8 eifr; /* Error Interrupt Factor Judge Register */
+ u8 recr; /* Receive Error Count Register */
+ u8 tecr; /* Transmit Error Count Register */
+ u8 ecsr; /* Error Code Store Register */
+ u8 cssr; /* Channel Search Support Register */
+ u8 mssr; /* Mailbox Search Status Register */
+ u8 msmr; /* Mailbox Search Mode Register */
+ u16 tsr; /* Time Stamp Register */
+ u8 afsr; /* Acceptance Filter Support Register */
+ u8 pad_857;
+ u8 tcr; /* Test Control Register */
+ u8 pad_859[7];
+ u8 ier; /* Interrupt Enable Register */
+ u8 isr; /* Interrupt Status Register */
+ u8 pad_862;
+ u8 mbsmr; /* Mailbox Search Mask Register */
+};
+
+struct rcar_can_priv {
+ struct can_priv can; /* Must be the first member! */
+ struct net_device *ndev;
+ struct napi_struct napi;
+ struct rcar_can_regs __iomem *regs;
+ struct clk *clk;
+ u8 tx_dlc[RCAR_CAN_FIFO_DEPTH];
+ u8 echo_skb_head;
+ u8 echo_skb_tail;
+ u8 clock_select;
+ u8 ier;
+};
+
+static const struct can_bittiming_const rcar_can_bittiming_const = {
+ .name = RCAR_CAN_DRV_NAME,
+ .tseg1_min = 4,
+ .tseg1_max = 16,
+ .tseg2_min = 2,
+ .tseg2_max = 8,
+ .sjw_max = 4,
+ .brp_min = 1,
+ .brp_max = 1024,
+ .brp_inc = 1,
+};
+
+/* Control Register bits */
+#define RCAR_CAN_CTLR_BOM (3 << 11) /* Bus-Off Recovery Mode Bits */
+#define RCAR_CAN_CTLR_BOM_ENT (1 << 11) /* Entry to halt mode */
+ /* at bus-off entry */
+#define RCAR_CAN_CTLR_SLPM (1 << 10)
+#define RCAR_CAN_CTLR_CANM (3 << 8) /* Operating Mode Select Bit */
+#define RCAR_CAN_CTLR_CANM_HALT (1 << 9)
+#define RCAR_CAN_CTLR_CANM_RESET (1 << 8)
+#define RCAR_CAN_CTLR_CANM_FORCE_RESET (3 << 8)
+#define RCAR_CAN_CTLR_MLM (1 << 3) /* Message Lost Mode Select */
+#define RCAR_CAN_CTLR_IDFM (3 << 1) /* ID Format Mode Select Bits */
+#define RCAR_CAN_CTLR_IDFM_MIXED (1 << 2) /* Mixed ID mode */
+#define RCAR_CAN_CTLR_MBM (1 << 0) /* Mailbox Mode select */
+
+/* Status Register bits */
+#define RCAR_CAN_STR_RSTST (1 << 8) /* Reset Status Bit */
+
+/* FIFO Received ID Compare Registers 0 and 1 bits */
+#define RCAR_CAN_FIDCR_IDE (1 << 31) /* ID Extension Bit */
+#define RCAR_CAN_FIDCR_RTR (1 << 30) /* Remote Transmission Request Bit */
+
+/* Receive FIFO Control Register bits */
+#define RCAR_CAN_RFCR_RFEST (1 << 7) /* Receive FIFO Empty Status Flag */
+#define RCAR_CAN_RFCR_RFE (1 << 0) /* Receive FIFO Enable */
+
+/* Transmit FIFO Control Register bits */
+#define RCAR_CAN_TFCR_TFUST (7 << 1) /* Transmit FIFO Unsent Message */
+ /* Number Status Bits */
+#define RCAR_CAN_TFCR_TFUST_SHIFT 1 /* Offset of Transmit FIFO Unsent */
+ /* Message Number Status Bits */
+#define RCAR_CAN_TFCR_TFE (1 << 0) /* Transmit FIFO Enable */
+
+#define RCAR_CAN_N_RX_MKREGS1 2 /* Number of mask registers */
+ /* for Rx mailboxes 0-31 */
+#define RCAR_CAN_N_RX_MKREGS2 8
+
+/* Bit Configuration Register settings */
+#define RCAR_CAN_BCR_TSEG1(x) (((x) & 0x0f) << 20)
+#define RCAR_CAN_BCR_BPR(x) (((x) & 0x3ff) << 8)
+#define RCAR_CAN_BCR_SJW(x) (((x) & 0x3) << 4)
+#define RCAR_CAN_BCR_TSEG2(x) ((x) & 0x07)
+
+/* Mailbox and Mask Registers bits */
+#define RCAR_CAN_IDE (1 << 31)
+#define RCAR_CAN_RTR (1 << 30)
+#define RCAR_CAN_SID_SHIFT 18
+
+/* Mailbox Interrupt Enable Register 1 bits */
+#define RCAR_CAN_MIER1_RXFIE (1 << 28) /* Receive FIFO Interrupt Enable */
+#define RCAR_CAN_MIER1_TXFIE (1 << 24) /* Transmit FIFO Interrupt Enable */
+
+/* Interrupt Enable Register bits */
+#define RCAR_CAN_IER_ERSIE (1 << 5) /* Error (ERS) Interrupt Enable Bit */
+#define RCAR_CAN_IER_RXFIE (1 << 4) /* Reception FIFO Interrupt */
+ /* Enable Bit */
+#define RCAR_CAN_IER_TXFIE (1 << 3) /* Transmission FIFO Interrupt */
+ /* Enable Bit */
+/* Interrupt Status Register bits */
+#define RCAR_CAN_ISR_ERSF (1 << 5) /* Error (ERS) Interrupt Status Bit */
+#define RCAR_CAN_ISR_RXFF (1 << 4) /* Reception FIFO Interrupt */
+ /* Status Bit */
+#define RCAR_CAN_ISR_TXFF (1 << 3) /* Transmission FIFO Interrupt */
+ /* Status Bit */
+
+/* Error Interrupt Enable Register bits */
+#define RCAR_CAN_EIER_BLIE (1 << 7) /* Bus Lock Interrupt Enable */
+#define RCAR_CAN_EIER_OLIE (1 << 6) /* Overload Frame Transmit */
+ /* Interrupt Enable */
+#define RCAR_CAN_EIER_ORIE (1 << 5) /* Receive Overrun Interrupt Enable */
+#define RCAR_CAN_EIER_BORIE (1 << 4) /* Bus-Off Recovery Interrupt Enable */
+#define RCAR_CAN_EIER_BOEIE (1 << 3) /* Bus-Off Entry Interrupt Enable */
+#define RCAR_CAN_EIER_EPIE (1 << 2) /* Error Passive Interrupt Enable */
+#define RCAR_CAN_EIER_EWIE (1 << 1) /* Error Warning Interrupt Enable */
+#define RCAR_CAN_EIER_BEIE (1 << 0) /* Bus Error Interrupt Enable */
+
+/* Error Interrupt Factor Judge Register bits */
+#define RCAR_CAN_EIFR_BLIF (1 << 7) /* Bus Lock Detect Flag */
+#define RCAR_CAN_EIFR_OLIF (1 << 6) /* Overload Frame Transmission */
+ /* Detect Flag */
+#define RCAR_CAN_EIFR_ORIF (1 << 5) /* Receive Overrun Detect Flag */
+#define RCAR_CAN_EIFR_BORIF (1 << 4) /* Bus-Off Recovery Detect Flag */
+#define RCAR_CAN_EIFR_BOEIF (1 << 3) /* Bus-Off Entry Detect Flag */
+#define RCAR_CAN_EIFR_EPIF (1 << 2) /* Error Passive Detect Flag */
+#define RCAR_CAN_EIFR_EWIF (1 << 1) /* Error Warning Detect Flag */
+#define RCAR_CAN_EIFR_BEIF (1 << 0) /* Bus Error Detect Flag */
+
+/* Error Code Store Register bits */
+#define RCAR_CAN_ECSR_EDPM (1 << 7) /* Error Display Mode Select Bit */
+#define RCAR_CAN_ECSR_ADEF (1 << 6) /* ACK Delimiter Error Flag */
+#define RCAR_CAN_ECSR_BE0F (1 << 5) /* Bit Error (dominant) Flag */
+#define RCAR_CAN_ECSR_BE1F (1 << 4) /* Bit Error (recessive) Flag */
+#define RCAR_CAN_ECSR_CEF (1 << 3) /* CRC Error Flag */
+#define RCAR_CAN_ECSR_AEF (1 << 2) /* ACK Error Flag */
+#define RCAR_CAN_ECSR_FEF (1 << 1) /* Form Error Flag */
+#define RCAR_CAN_ECSR_SEF (1 << 0) /* Stuff Error Flag */
+
+#define RCAR_CAN_NAPI_WEIGHT 4
+#define MAX_STR_READS 0x100
+
+static void tx_failure_cleanup(struct net_device *ndev)
+{
+ int i;
+
+ for (i = 0; i < RCAR_CAN_FIFO_DEPTH; i++)
+ can_free_echo_skb(ndev, i);
+}
+
+static void rcar_can_error(struct net_device *ndev)
+{
+ struct rcar_can_priv *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &ndev->stats;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+ u8 eifr, txerr = 0, rxerr = 0;
+
+ /* Propagate the error condition to the CAN stack */
+ skb = alloc_can_err_skb(ndev, &cf);
+ if (!skb)
+ return;
+
+ eifr = readb(&priv->regs->eifr);
+ if (eifr & (RCAR_CAN_EIFR_EWIF | RCAR_CAN_EIFR_EPIF)) {
+ cf->can_id |= CAN_ERR_CRTL;
+ txerr = readb(&priv->regs->tecr);
+ rxerr = readb(&priv->regs->recr);
+ cf->data[6] = txerr;
+ cf->data[7] = rxerr;
+ }
+ if (eifr & RCAR_CAN_EIFR_BEIF) {
+ int rx_errors = 0, tx_errors = 0;
+ u8 ecsr;
+
+ netdev_dbg(priv->ndev, "Bus error interrupt:\n");
+ cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
+ cf->data[2] = CAN_ERR_PROT_UNSPEC;
+
+ ecsr = readb(&priv->regs->ecsr);
+ if (ecsr & RCAR_CAN_ECSR_ADEF) {
+ netdev_dbg(priv->ndev, "ACK Delimiter Error\n");
+ cf->data[3] |= CAN_ERR_PROT_LOC_ACK_DEL;
+ tx_errors++;
+ writeb(~RCAR_CAN_ECSR_ADEF, &priv->regs->ecsr);
+ }
+ if (ecsr & RCAR_CAN_ECSR_BE0F) {
+ netdev_dbg(priv->ndev, "Bit Error (dominant)\n");
+ cf->data[2] |= CAN_ERR_PROT_BIT0;
+ tx_errors++;
+ writeb(~RCAR_CAN_ECSR_BE0F, &priv->regs->ecsr);
+ }
+ if (ecsr & RCAR_CAN_ECSR_BE1F) {
+ netdev_dbg(priv->ndev, "Bit Error (recessive)\n");
+ cf->data[2] |= CAN_ERR_PROT_BIT1;
+ tx_errors++;
+ writeb(~RCAR_CAN_ECSR_BE1F, &priv->regs->ecsr);
+ }
+ if (ecsr & RCAR_CAN_ECSR_CEF) {
+ netdev_dbg(priv->ndev, "CRC Error\n");
+ cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
+ rx_errors++;
+ writeb(~RCAR_CAN_ECSR_CEF, &priv->regs->ecsr);
+ }
+ if (ecsr & RCAR_CAN_ECSR_AEF) {
+ netdev_dbg(priv->ndev, "ACK Error\n");
+ cf->can_id |= CAN_ERR_ACK;
+ cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
+ tx_errors++;
+ writeb(~RCAR_CAN_ECSR_AEF, &priv->regs->ecsr);
+ }
+ if (ecsr & RCAR_CAN_ECSR_FEF) {
+ netdev_dbg(priv->ndev, "Form Error\n");
+ cf->data[2] |= CAN_ERR_PROT_FORM;
+ rx_errors++;
+ writeb(~RCAR_CAN_ECSR_FEF, &priv->regs->ecsr);
+ }
+ if (ecsr & RCAR_CAN_ECSR_SEF) {
+ netdev_dbg(priv->ndev, "Stuff Error\n");
+ cf->data[2] |= CAN_ERR_PROT_STUFF;
+ rx_errors++;
+ writeb(~RCAR_CAN_ECSR_SEF, &priv->regs->ecsr);
+ }
+
+ priv->can.can_stats.bus_error++;
+ ndev->stats.rx_errors += rx_errors;
+ ndev->stats.tx_errors += tx_errors;
+ writeb(~RCAR_CAN_EIFR_BEIF, &priv->regs->eifr);
+ }
+ if (eifr & RCAR_CAN_EIFR_EWIF) {
+ netdev_dbg(priv->ndev, "Error warning interrupt\n");
+ priv->can.state = CAN_STATE_ERROR_WARNING;
+ priv->can.can_stats.error_warning++;
+ cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_WARNING :
+ CAN_ERR_CRTL_RX_WARNING;
+ /* Clear interrupt condition */
+ writeb(~RCAR_CAN_EIFR_EWIF, &priv->regs->eifr);
+ }
+ if (eifr & RCAR_CAN_EIFR_EPIF) {
+ netdev_dbg(priv->ndev, "Error passive interrupt\n");
+ priv->can.state = CAN_STATE_ERROR_PASSIVE;
+ priv->can.can_stats.error_passive++;
+ cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_PASSIVE :
+ CAN_ERR_CRTL_RX_PASSIVE;
+ /* Clear interrupt condition */
+ writeb(~RCAR_CAN_EIFR_EPIF, &priv->regs->eifr);
+ }
+ if (eifr & RCAR_CAN_EIFR_BOEIF) {
+ netdev_dbg(priv->ndev, "Bus-off entry interrupt\n");
+ tx_failure_cleanup(ndev);
+ priv->ier = RCAR_CAN_IER_ERSIE;
+ writeb(priv->ier, &priv->regs->ier);
+ priv->can.state = CAN_STATE_BUS_OFF;
+ cf->can_id |= CAN_ERR_BUSOFF;
+ /* Clear interrupt condition */
+ writeb(~RCAR_CAN_EIFR_BOEIF, &priv->regs->eifr);
+ can_bus_off(ndev);
+ }
+ if (eifr & RCAR_CAN_EIFR_ORIF) {
+ netdev_dbg(priv->ndev, "Receive overrun error interrupt\n");
+ cf->can_id |= CAN_ERR_CRTL;
+ cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+ ndev->stats.rx_over_errors++;
+ ndev->stats.rx_errors++;
+ writeb(~RCAR_CAN_EIFR_ORIF, &priv->regs->eifr);
+ }
+ if (eifr & RCAR_CAN_EIFR_OLIF) {
+ netdev_dbg(priv->ndev,
+ "Overload Frame Transmission error interrupt\n");
+ cf->can_id |= CAN_ERR_PROT;
+ cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
+ ndev->stats.rx_over_errors++;
+ ndev->stats.rx_errors++;
+ writeb(~RCAR_CAN_EIFR_OLIF, &priv->regs->eifr);
+ }
+
+ netif_rx(skb);
+ stats->rx_packets++;
+ stats->rx_bytes += cf->can_dlc;
+}
+
+static void rcar_can_tx_done(struct net_device *ndev)
+{
+ struct rcar_can_priv *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &ndev->stats;
+
+ stats->tx_packets++;
+ stats->tx_bytes += priv->tx_dlc[priv->echo_skb_tail];
+ priv->tx_dlc[priv->echo_skb_tail] = 0;
+ can_get_echo_skb(ndev, priv->echo_skb_tail);
+ if (++priv->echo_skb_tail >= RCAR_CAN_FIFO_DEPTH)
+ priv->echo_skb_tail = 0;
+ can_led_event(ndev, CAN_LED_EVENT_TX);
+ netif_wake_queue(ndev);
+}
+
+static irqreturn_t rcar_can_interrupt(int irq, void *dev_id)
+{
+ struct net_device *ndev = dev_id;
+ struct rcar_can_priv *priv = netdev_priv(ndev);
+ u8 isr;
+
+ isr = readb(&priv->regs->isr);
+ if (!(isr & priv->ier))
+ return IRQ_NONE;
+
+ if (isr & RCAR_CAN_ISR_ERSF)
+ rcar_can_error(ndev);
+
+ if (isr & RCAR_CAN_ISR_TXFF) {
+ /* Clear interrupt */
+ writeb(isr & ~RCAR_CAN_ISR_TXFF, &priv->regs->isr);
+ rcar_can_tx_done(ndev);
+ }
+
+ if (isr & RCAR_CAN_ISR_RXFF) {
+ if (napi_schedule_prep(&priv->napi)) {
+ /* Disable Rx FIFO interrupts */
+ priv->ier &= ~RCAR_CAN_IER_RXFIE;
+ writeb(priv->ier, &priv->regs->ier);
+ __napi_schedule(&priv->napi);
+ }
+ }
+
+ return IRQ_HANDLED;
+}
+
+static void rcar_can_set_bittiming(struct net_device *dev)
+{
+ struct rcar_can_priv *priv = netdev_priv(dev);
+ struct can_bittiming *bt = &priv->can.bittiming;
+ u32 bcr;
+ u8 clkr;
+
+ /* Don't overwrite CLKR with 32-bit BCR access */
+ /* CLKR has 8-bit access */
+ clkr = readb(&priv->regs->clkr);
+ bcr = RCAR_CAN_BCR_TSEG1(bt->phase_seg1 + bt->prop_seg - 1) |
+ RCAR_CAN_BCR_BPR(bt->brp - 1) | RCAR_CAN_BCR_SJW(bt->sjw - 1) |
+ RCAR_CAN_BCR_TSEG2(bt->phase_seg2 - 1);
+ /* All the registers are big-endian but they get byte-swapped on 32-bit
+ * read/write (but not on 8-bit, contrary to the manuals)...
+ */
+ writel((bcr << 8) | clkr, &priv->regs->bcr);
+}
+
+static void rcar_can_start(struct net_device *ndev)
+{
+ struct rcar_can_priv *priv = netdev_priv(ndev);
+ u16 ctlr;
+ int i;
+
+ /* Set controller to known mode:
+ * - FIFO mailbox mode
+ * - accept all messages
+ * - overrun mode
+ * CAN is in sleep mode after MCU hardware or software reset.
+ */
+ ctlr = readw(&priv->regs->ctlr);
+ ctlr &= ~RCAR_CAN_CTLR_SLPM;
+ writew(ctlr, &priv->regs->ctlr);
+ /* Go to reset mode */
+ ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET;
+ writew(ctlr, &priv->regs->ctlr);
+ for (i = 0; i < MAX_STR_READS; i++) {
+ if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)
+ break;
+ }
+ rcar_can_set_bittiming(ndev);
+ ctlr |= RCAR_CAN_CTLR_IDFM_MIXED; /* Select mixed ID mode */
+ ctlr |= RCAR_CAN_CTLR_BOM_ENT; /* Entry to halt mode automatically */
+ /* at bus-off */
+ ctlr |= RCAR_CAN_CTLR_MBM; /* Select FIFO mailbox mode */
+ ctlr |= RCAR_CAN_CTLR_MLM; /* Overrun mode */
+ writew(ctlr, &priv->regs->ctlr);
+
+ writeb(priv->clock_select, &priv->regs->clkr);
+
+ /* Accept all SID and EID */
+ writel(0, &priv->regs->mkr_2_9[6]);
+ writel(0, &priv->regs->mkr_2_9[7]);
+ /* In FIFO mailbox mode, write "0" to bits 24 to 31 */
+ writel(0, &priv->regs->mkivlr1);
+ /* Accept all frames */
+ writel(0, &priv->regs->fidcr[0]);
+ writel(RCAR_CAN_FIDCR_IDE | RCAR_CAN_FIDCR_RTR, &priv->regs->fidcr[1]);
+ /* Enable and configure FIFO mailbox interrupts */
+ writel(RCAR_CAN_MIER1_RXFIE | RCAR_CAN_MIER1_TXFIE, &priv->regs->mier1);
+
+ priv->ier = RCAR_CAN_IER_ERSIE | RCAR_CAN_IER_RXFIE |
+ RCAR_CAN_IER_TXFIE;
+ writeb(priv->ier, &priv->regs->ier);
+
+ /* Accumulate error codes */
+ writeb(RCAR_CAN_ECSR_EDPM, &priv->regs->ecsr);
+ /* Enable error interrupts */
+ writeb(RCAR_CAN_EIER_EWIE | RCAR_CAN_EIER_EPIE | RCAR_CAN_EIER_BOEIE |
+ (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING ?
+ RCAR_CAN_EIER_BEIE : 0) | RCAR_CAN_EIER_ORIE |
+ RCAR_CAN_EIER_OLIE, &priv->regs->eier);
+ priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+ /* Go to operation mode */
+ writew(ctlr & ~RCAR_CAN_CTLR_CANM, &priv->regs->ctlr);
+ for (i = 0; i < MAX_STR_READS; i++) {
+ if (!(readw(&priv->regs->str) & RCAR_CAN_STR_RSTST))
+ break;
+ }
+ /* Enable Rx and Tx FIFO */
+ writeb(RCAR_CAN_RFCR_RFE, &priv->regs->rfcr);
+ writeb(RCAR_CAN_TFCR_TFE, &priv->regs->tfcr);
+}
+
+static int rcar_can_open(struct net_device *ndev)
+{
+ struct rcar_can_priv *priv = netdev_priv(ndev);
+ int err;
+
+ err = clk_prepare_enable(priv->clk);
+ if (err) {
+ netdev_err(ndev, "clk_prepare_enable() failed, error %d\n",
+ err);
+ goto out;
+ }
+ err = open_candev(ndev);
+ if (err) {
+ netdev_err(ndev, "open_candev() failed, error %d\n", err);
+ goto out_clock;
+ }
+ napi_enable(&priv->napi);
+ err = request_irq(ndev->irq, rcar_can_interrupt, 0, ndev->name, ndev);
+ if (err) {
+ netdev_err(ndev, "error requesting interrupt %x\n", ndev->irq);
+ goto out_close;
+ }
+ can_led_event(ndev, CAN_LED_EVENT_OPEN);
+ rcar_can_start(ndev);
+ netif_start_queue(ndev);
+ return 0;
+out_close:
+ napi_disable(&priv->napi);
+ close_candev(ndev);
+out_clock:
+ clk_disable_unprepare(priv->clk);
+out:
+ return err;
+}
+
+static void rcar_can_stop(struct net_device *ndev)
+{
+ struct rcar_can_priv *priv = netdev_priv(ndev);
+ u16 ctlr;
+ int i;
+
+ /* Go to (force) reset mode */
+ ctlr = readw(&priv->regs->ctlr);
+ ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET;
+ writew(ctlr, &priv->regs->ctlr);
+ for (i = 0; i < MAX_STR_READS; i++) {
+ if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)
+ break;
+ }
+ writel(0, &priv->regs->mier0);
+ writel(0, &priv->regs->mier1);
+ writeb(0, &priv->regs->ier);
+ writeb(0, &priv->regs->eier);
+ /* Go to sleep mode */
+ ctlr |= RCAR_CAN_CTLR_SLPM;
+ writew(ctlr, &priv->regs->ctlr);
+ priv->can.state = CAN_STATE_STOPPED;
+}
+
+static int rcar_can_close(struct net_device *ndev)
+{
+ struct rcar_can_priv *priv = netdev_priv(ndev);
+
+ netif_stop_queue(ndev);
+ rcar_can_stop(ndev);
+ free_irq(ndev->irq, ndev);
+ napi_disable(&priv->napi);
+ clk_disable_unprepare(priv->clk);
+ close_candev(ndev);
+ can_led_event(ndev, CAN_LED_EVENT_STOP);
+ return 0;
+}
+
+static netdev_tx_t rcar_can_start_xmit(struct sk_buff *skb,
+ struct net_device *ndev)
+{
+ struct rcar_can_priv *priv = netdev_priv(ndev);
+ struct can_frame *cf = (struct can_frame *)skb->data;
+ u32 data, i;
+ u8 tfcr;
+
+ if (can_dropped_invalid_skb(ndev, skb))
+ return NETDEV_TX_OK;
+ tfcr = readb(&priv->regs->tfcr);
+ /* Stop queue if we are to fill the last FIFO entry */
+ if ((tfcr & RCAR_CAN_TFCR_TFUST) >> RCAR_CAN_TFCR_TFUST_SHIFT >= 3)
+ netif_stop_queue(ndev);
+
+ if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
+ data = (cf->can_id & CAN_EFF_MASK) | RCAR_CAN_IDE;
+ else /* Standard frame format */
+ data = (cf->can_id & CAN_SFF_MASK) << RCAR_CAN_SID_SHIFT;
+
+ if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */
+ data |= RCAR_CAN_RTR;
+
+ writel(data, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].id);
+
+ writeb(cf->can_dlc, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].dlc);
+
+ for (i = 0; i < cf->can_dlc; i++)
+ writeb(cf->data[i],
+ &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].data[i]);
+
+ priv->tx_dlc[priv->echo_skb_head] = cf->can_dlc;
+ can_put_echo_skb(skb, ndev, priv->echo_skb_head);
+ if (++priv->echo_skb_head >= RCAR_CAN_FIFO_DEPTH)
+ priv->echo_skb_head = 0;
+ /* Start Tx: write 0xff to the TFPCR register to increment
+ * the CPU-side pointer for the transmit FIFO to the next
+ * mailbox location
+ */
+ writeb(0xff, &priv->regs->tfpcr);
+
+ return NETDEV_TX_OK;
+}
+
+static const struct net_device_ops rcar_can_netdev_ops = {
+ .ndo_open = rcar_can_open,
+ .ndo_stop = rcar_can_close,
+ .ndo_start_xmit = rcar_can_start_xmit,
+};
+
+static void rcar_can_rx_pkt(struct rcar_can_priv *priv)
+{
+ struct net_device_stats *stats = &priv->ndev->stats;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+ u32 data;
+ u8 dlc;
+
+ skb = alloc_can_skb(priv->ndev, &cf);
+ if (!skb) {
+ stats->rx_dropped++;
+ return;
+ }
+
+ data = readl(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].id);
+ if (data & RCAR_CAN_IDE)
+ cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
+ else
+ cf->can_id = (data >> RCAR_CAN_SID_SHIFT) & CAN_SFF_MASK;
+
+ dlc = readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].dlc);
+ cf->can_dlc = get_can_dlc(dlc);
+ if (data & RCAR_CAN_RTR) {
+ cf->can_id |= CAN_RTR_FLAG;
+ } else {
+ for (dlc = 0; dlc < cf->can_dlc; dlc++)
+ cf->data[dlc] =
+ readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].data[dlc]);
+ }
+
+ can_led_event(priv->ndev, CAN_LED_EVENT_RX);
+
+ netif_receive_skb(skb);
+ stats->rx_bytes += cf->can_dlc;
+ stats->rx_packets++;
+}
+
+static int rcar_can_rx_poll(struct napi_struct *napi, int quota)
+{
+ struct rcar_can_priv *priv = container_of(napi,
+ struct rcar_can_priv, napi);
+ int num_pkts;
+
+ for (num_pkts = 0; num_pkts < quota; num_pkts++) {
+ u8 rfcr, isr;
+
+ isr = readb(&priv->regs->isr);
+ /* Clear interrupt bit */
+ if (isr & RCAR_CAN_ISR_RXFF)
+ writeb(isr & ~RCAR_CAN_ISR_RXFF, &priv->regs->isr);
+ rfcr = readb(&priv->regs->rfcr);
+ if (rfcr & RCAR_CAN_RFCR_RFEST)
+ break;
+ rcar_can_rx_pkt(priv);
+ /* Write 0xff to the RFPCR register to increment
+ * the CPU-side pointer for the receive FIFO
+ * to the next mailbox location
+ */
+ writeb(0xff, &priv->regs->rfpcr);
+ }
+ /* All packets processed */
+ if (num_pkts < quota) {
+ napi_complete(napi);
+ priv->ier |= RCAR_CAN_IER_RXFIE;
+ writeb(priv->ier, &priv->regs->ier);
+ }
+ return num_pkts;
+}
+
+static int rcar_can_do_set_mode(struct net_device *ndev, enum can_mode mode)
+{
+ switch (mode) {
+ case CAN_MODE_START:
+ rcar_can_start(ndev);
+ netif_wake_queue(ndev);
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int rcar_can_get_berr_counter(const struct net_device *dev,
+ struct can_berr_counter *bec)
+{
+ struct rcar_can_priv *priv = netdev_priv(dev);
+ int err;
+
+ err = clk_prepare_enable(priv->clk);
+ if (err)
+ return err;
+ bec->txerr = readb(&priv->regs->tecr);
+ bec->rxerr = readb(&priv->regs->recr);
+ clk_disable_unprepare(priv->clk);
+ return 0;
+}
+
+static int rcar_can_probe(struct platform_device *pdev)
+{
+ struct rcar_can_platform_data *pdata;
+ struct rcar_can_priv *priv;
+ struct net_device *ndev;
+ struct resource *mem;
+ void __iomem *addr;
+ int err = -ENODEV;
+ int irq;
+
+ pdata = dev_get_platdata(&pdev->dev);
+ if (!pdata) {
+ dev_err(&pdev->dev, "No platform data provided!\n");
+ goto fail;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (!irq) {
+ dev_err(&pdev->dev, "No IRQ resource\n");
+ goto fail;
+ }
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ addr = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(addr)) {
+ err = PTR_ERR(addr);
+ goto fail;
+ }
+
+ ndev = alloc_candev(sizeof(struct rcar_can_priv), RCAR_CAN_FIFO_DEPTH);
+ if (!ndev) {
+ dev_err(&pdev->dev, "alloc_candev() failed\n");
+ err = -ENOMEM;
+ goto fail;
+ }
+
+ priv = netdev_priv(ndev);
+
+ priv->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(priv->clk)) {
+ err = PTR_ERR(priv->clk);
+ dev_err(&pdev->dev, "cannot get clock: %d\n", err);
+ goto fail_clk;
+ }
+
+ ndev->netdev_ops = &rcar_can_netdev_ops;
+ ndev->irq = irq;
+ ndev->flags |= IFF_ECHO;
+ priv->ndev = ndev;
+ priv->regs = addr;
+ priv->clock_select = pdata->clock_select;
+ priv->can.clock.freq = clk_get_rate(priv->clk);
+ priv->can.bittiming_const = &rcar_can_bittiming_const;
+ priv->can.do_set_mode = rcar_can_do_set_mode;
+ priv->can.do_get_berr_counter = rcar_can_get_berr_counter;
+ priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING;
+ platform_set_drvdata(pdev, ndev);
+ SET_NETDEV_DEV(ndev, &pdev->dev);
+
+ netif_napi_add(ndev, &priv->napi, rcar_can_rx_poll,
+ RCAR_CAN_NAPI_WEIGHT);
+ err = register_candev(ndev);
+ if (err) {
+ dev_err(&pdev->dev, "register_candev() failed, error %d\n",
+ err);
+ goto fail_candev;
+ }
+
+ devm_can_led_init(ndev);
+
+ dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n",
+ priv->regs, ndev->irq);
+
+ return 0;
+fail_candev:
+ netif_napi_del(&priv->napi);
+fail_clk:
+ free_candev(ndev);
+fail:
+ return err;
+}
+
+static int rcar_can_remove(struct platform_device *pdev)
+{
+ struct net_device *ndev = platform_get_drvdata(pdev);
+ struct rcar_can_priv *priv = netdev_priv(ndev);
+
+ unregister_candev(ndev);
+ netif_napi_del(&priv->napi);
+ free_candev(ndev);
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int rcar_can_suspend(struct device *dev)
+{
+ struct net_device *ndev = dev_get_drvdata(dev);
+ struct rcar_can_priv *priv = netdev_priv(ndev);
+ u16 ctlr;
+
+ if (netif_running(ndev)) {
+ netif_stop_queue(ndev);
+ netif_device_detach(ndev);
+ }
+ ctlr = readw(&priv->regs->ctlr);
+ ctlr |= RCAR_CAN_CTLR_CANM_HALT;
+ writew(ctlr, &priv->regs->ctlr);
+ ctlr |= RCAR_CAN_CTLR_SLPM;
+ writew(ctlr, &priv->regs->ctlr);
+ priv->can.state = CAN_STATE_SLEEPING;
+
+ clk_disable(priv->clk);
+ return 0;
+}
+
+static int rcar_can_resume(struct device *dev)
+{
+ struct net_device *ndev = dev_get_drvdata(dev);
+ struct rcar_can_priv *priv = netdev_priv(ndev);
+ u16 ctlr;
+ int err;
+
+ err = clk_enable(priv->clk);
+ if (err) {
+ netdev_err(ndev, "clk_enable() failed, error %d\n", err);
+ return err;
+ }
+
+ ctlr = readw(&priv->regs->ctlr);
+ ctlr &= ~RCAR_CAN_CTLR_SLPM;
+ writew(ctlr, &priv->regs->ctlr);
+ ctlr &= ~RCAR_CAN_CTLR_CANM;
+ writew(ctlr, &priv->regs->ctlr);
+ 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(rcar_can_pm_ops, rcar_can_suspend, rcar_can_resume);
+
+static struct platform_driver rcar_can_driver = {
+ .driver = {
+ .name = RCAR_CAN_DRV_NAME,
+ .owner = THIS_MODULE,
+ .pm = &rcar_can_pm_ops,
+ },
+ .probe = rcar_can_probe,
+ .remove = rcar_can_remove,
+};
+
+module_platform_driver(rcar_can_driver);
+
+MODULE_AUTHOR("Cogent Embedded, Inc.");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CAN driver for Renesas R-Car SoC");
+MODULE_ALIAS("platform:" RCAR_CAN_DRV_NAME);
Index: linux-can-next/include/linux/can/platform/rcar_can.h
===================================================================
--- /dev/null
+++ linux-can-next/include/linux/can/platform/rcar_can.h
@@ -0,0 +1,17 @@
+#ifndef _CAN_PLATFORM_RCAR_CAN_H_
+#define _CAN_PLATFORM_RCAR_CAN_H_
+
+#include <linux/types.h>
+
+/* Clock Select Register settings */
+enum CLKR {
+ CLKR_CLKP1 = 0, /* Peripheral clock (clkp1) */
+ CLKR_CLKP2 = 1, /* Peripheral clock (clkp2) */
+ CLKR_CLKEXT = 3 /* Externally input clock */
+};
+
+struct rcar_can_platform_data {
+ enum CLKR clock_select; /* Clock source select */
+};
+
+#endif /* !_CAN_PLATFORM_RCAR_CAN_H_ */
--
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