From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH v5 2/2] can: Allwinner A10/A20 CAN Controller support - controller code Date: Sun, 13 Sep 2015 14:45:01 +0200 Message-ID: <20150913124501.GS9885@lukather> References: <1442144632-4541-1-git-send-email-info@gerhard-bertelsmann.de> <1442144632-4541-3-git-send-email-info@gerhard-bertelsmann.de> Reply-To: maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="R0KbGFzrRdaLlFh/" Return-path: Content-Disposition: inline In-Reply-To: <1442144632-4541-3-git-send-email-info-La43T0Mi4bH5xCKuJOYmCvaTkwRoYoCU@public.gmane.org> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Gerhard Bertelsmann Cc: linux-can-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, mkl-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org List-Id: linux-can.vger.kernel.org --R0KbGFzrRdaLlFh/ Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Hi! On Sun, Sep 13, 2015 at 01:43:52PM +0200, Gerhard Bertelsmann wrote: > Signed-off-by: Gerhard Bertelsmann And one commit log here too please :) > --- > drivers/net/can/Kconfig | 10 + > drivers/net/can/Makefile | 1 + > drivers/net/can/sunxi_can.c | 879 +++++++++++++++++++++ > 3 files changed, 890 insertions(+) > > diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig > index e8c96b8..439f67c 100644 > --- a/drivers/net/can/Kconfig > +++ b/drivers/net/can/Kconfig > @@ -129,6 +129,16 @@ config CAN_RCAR > To compile this driver as a module, choose M here: the module will > be called rcar_can. > > +config CAN_SUNXI > + tristate "Allwinner SUNXI CAN controller" It would be better if we could mention that it's a driver for the sun4i family and derived. We have no guarantee that there won't be any IP on other sunxi SoCs incompatible with this one that would need a new driver. Something like CAN_SUN4I (and the driver sun4i_can.c) would be great. (This also applies to all the symbols/defines/etc inside the driver, for consistency). > + depends on MACH_SUN4I || MACH_SUN7I || COMPILE_TEST > + ---help--- > + Say Y here if you want to use CAN controller found on Allwinner > + A10/A20 SoCs. > + > + To compile this driver as a module, choose M here: the module will > + be called rcar_can. You're sure about the name of the compiled module? > + > config CAN_XILINXCAN > tristate "Xilinx CAN" > depends on ARCH_ZYNQ || ARM64 || MICROBLAZE || COMPILE_TEST > diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile > index c533c62..b3e825c 100644 > --- a/drivers/net/can/Makefile > +++ b/drivers/net/can/Makefile > @@ -27,6 +27,7 @@ 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 > +obj-$(CONFIG_CAN_SUNXI) += sunxi_can.o > obj-$(CONFIG_CAN_XILINXCAN) += xilinx_can.o > > subdir-ccflags-y += -D__CHECK_ENDIAN__ > diff --git a/drivers/net/can/sunxi_can.c b/drivers/net/can/sunxi_can.c > new file mode 100644 > index 0000000..569e6cd > --- /dev/null > +++ b/drivers/net/can/sunxi_can.c > @@ -0,0 +1,879 @@ > +/* > + * sunxi_can.c - CAN bus controller driver for Allwinner SUN4I&SUN7I based SoCs > + * > + * Copyright (C) 2013 Peter Chen > + * Copyright (C) 2015 Gerhard Bertelsmann > + * All rights reserved. > + * > + * Parts of this software are based on (derived from) the SJA1000 code by: > + * Copyright (C) 2014 Oliver Hartkopp > + * Copyright (C) 2007 Wolfgang Grandegger > + * Copyright (C) 2002-2007 Volkswagen Group Electronic Research > + * Copyright (C) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33, > + * 38106 Braunschweig, GERMANY > + * > + * Redistribution and use in source and binary forms, with or without > + * modification, are permitted provided that the following conditions > + * are met: > + * 1. Redistributions of source code must retain the above copyright > + * notice, this list of conditions and the following disclaimer. > + * 2. Redistributions in binary form must reproduce the above copyright > + * notice, this list of conditions and the following disclaimer in the > + * documentation and/or other materials provided with the distribution. > + * 3. Neither the name of Volkswagen nor the names of its contributors > + * may be used to endorse or promote products derived from this software > + * without specific prior written permission. > + * > + * Alternatively, provided that this notice is retained in full, this > + * software may be distributed under the terms of the GNU General > + * Public License ("GPL") version 2, in which case the provisions of the > + * GPL apply INSTEAD OF those given above. > + * > + * The provided data structures and external interfaces from this code > + * are not restricted to be used by modules with a GPL compatible license. > + * > + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS > + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT > + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR > + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT > + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, > + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT > + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, > + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY > + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT > + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE > + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH > + * DAMAGE. > + * > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define DRV_NAME "sunxi_can" > +#define DRV_MODULE_VERSION "0.99" > + > +/* Registers address (physical base address 0x01C2BC00) */ > +#define SUNXI_REG_MSEL_ADDR 0x0000 /* CAN Mode Select */ > +#define SUNXI_REG_CMD_ADDR 0x0004 /* CAN Command */ > +#define SUNXI_REG_STA_ADDR 0x0008 /* CAN Status */ > +#define SUNXI_REG_INT_ADDR 0x000c /* CAN Interrupt Flag */ > +#define SUNXI_REG_INTEN_ADDR 0x0010 /* CAN Interrupt Enable */ > +#define SUNXI_REG_BTIME_ADDR 0x0014 /* CAN Bus Timing 0 */ > +#define SUNXI_REG_TEWL_ADDR 0x0018 /* CAN Tx Error Warning Limit */ > +#define SUNXI_REG_ERRC_ADDR 0x001c /* CAN Error Counter */ > +#define SUNXI_REG_RMCNT_ADDR 0x0020 /* CAN Receive Message Counter */ > +#define SUNXI_REG_RBUFSA_ADDR 0x0024 /* CAN Receive Buffer Start Address */ > +#define SUNXI_REG_BUF0_ADDR 0x0040 /* CAN Tx/Rx Buffer 0 */ > +#define SUNXI_REG_BUF1_ADDR 0x0044 /* CAN Tx/Rx Buffer 1 */ > +#define SUNXI_REG_BUF2_ADDR 0x0048 /* CAN Tx/Rx Buffer 2 */ > +#define SUNXI_REG_BUF3_ADDR 0x004c /* CAN Tx/Rx Buffer 3 */ > +#define SUNXI_REG_BUF4_ADDR 0x0050 /* CAN Tx/Rx Buffer 4 */ > +#define SUNXI_REG_BUF5_ADDR 0x0054 /* CAN Tx/Rx Buffer 5 */ > +#define SUNXI_REG_BUF6_ADDR 0x0058 /* CAN Tx/Rx Buffer 6 */ > +#define SUNXI_REG_BUF7_ADDR 0x005c /* CAN Tx/Rx Buffer 7 */ > +#define SUNXI_REG_BUF8_ADDR 0x0060 /* CAN Tx/Rx Buffer 8 */ > +#define SUNXI_REG_BUF9_ADDR 0x0064 /* CAN Tx/Rx Buffer 9 */ > +#define SUNXI_REG_BUF10_ADDR 0x0068 /* CAN Tx/Rx Buffer 10 */ > +#define SUNXI_REG_BUF11_ADDR 0x006c /* CAN Tx/Rx Buffer 11 */ > +#define SUNXI_REG_BUF12_ADDR 0x0070 /* CAN Tx/Rx Buffer 12 */ > +#define SUNXI_REG_ACPC_ADDR 0x0040 /* CAN Acceptance Code 0 */ > +#define SUNXI_REG_ACPM_ADDR 0x0044 /* CAN Acceptance Mask 0 */ > +#define SUNXI_REG_RBUF_RBACK_START_ADDR 0x0180 /* CAN transmit buffer start */ > +#define SUNXI_REG_RBUF_RBACK_END_ADDR 0x01b0 /* CAN transmit buffer end */ > + > +/* Controller Register Description */ > + > +/* mode select register (r/w) > + * offset:0x0000 default:0x0000_0001 > + */ > +#define SUNXI_MSEL_SLEEP_MODE (0x01 << 4) /* write in reset mode */ > +#define SUNXI_MSEL_WAKE_UP (0x00 << 4) > +#define SUNXI_MSEL_SINGLE_FILTER (0x01 << 3) /* write in reset mode */ > +#define SUNXI_MSEL_DUAL_FILTERS (0x00 << 3) > +#define SUNXI_MSEL_LOOPBACK_MODE BIT(2) > +#define SUNXI_MSEL_LISTEN_ONLY_MODE BIT(1) > +#define SUNXI_MSEL_RESET_MODE BIT(0) > + > +/* command register (w) > + * offset:0x0004 default:0x0000_0000 > + */ > +#define SUNXI_CMD_BUS_OFF_REQ BIT(5) > +#define SUNXI_CMD_SELF_RCV_REQ BIT(4) > +#define SUNXI_CMD_CLEAR_OR_FLAG BIT(3) > +#define SUNXI_CMD_RELEASE_RBUF BIT(2) > +#define SUNXI_CMD_ABORT_REQ BIT(1) > +#define SUNXI_CMD_TRANS_REQ BIT(0) > + > +/* status register (r) > + * offset:0x0008 default:0x0000_003c > + */ > +#define SUNXI_STA_BIT_ERR (0x00 << 22) > +#define SUNXI_STA_FORM_ERR (0x01 << 22) > +#define SUNXI_STA_STUFF_ERR (0x02 << 22) > +#define SUNXI_STA_OTHER_ERR (0x03 << 22) > +#define SUNXI_STA_MASK_ERR (0x03 << 22) > +#define SUNXI_STA_ERR_DIR BIT(21) > +#define SUNXI_STA_ERR_SEG_CODE (0x1f << 16) > +#define SUNXI_STA_START (0x03 << 16) > +#define SUNXI_STA_ID28_21 (0x02 << 16) > +#define SUNXI_STA_ID20_18 (0x06 << 16) > +#define SUNXI_STA_SRTR (0x04 << 16) > +#define SUNXI_STA_IDE (0x05 << 16) > +#define SUNXI_STA_ID17_13 (0x07 << 16) > +#define SUNXI_STA_ID12_5 (0x0f << 16) > +#define SUNXI_STA_ID4_0 (0x0e << 16) > +#define SUNXI_STA_RTR (0x0c << 16) > +#define SUNXI_STA_RB1 (0x0d << 16) > +#define SUNXI_STA_RB0 (0x09 << 16) > +#define SUNXI_STA_DLEN (0x0b << 16) > +#define SUNXI_STA_DATA_FIELD (0x0a << 16) > +#define SUNXI_STA_CRC_SEQUENCE (0x08 << 16) > +#define SUNXI_STA_CRC_DELIMITER (0x18 << 16) > +#define SUNXI_STA_ACK (0x19 << 16) > +#define SUNXI_STA_ACK_DELIMITER (0x1b << 16) > +#define SUNXI_STA_END (0x1a << 16) > +#define SUNXI_STA_INTERMISSION (0x12 << 16) > +#define SUNXI_STA_ACTIVE_ERROR (0x11 << 16) > +#define SUNXI_STA_PASSIVE_ERROR (0x16 << 16) > +#define SUNXI_STA_TOLERATE_DOMINANT_BITS (0x13 << 16) > +#define SUNXI_STA_ERROR_DELIMITER (0x17 << 16) > +#define SUNXI_STA_OVERLOAD (0x1c << 16) > +#define SUNXI_STA_BUS_OFF BIT(7) > +#define SUNXI_STA_ERR_STA BIT(6) > +#define SUNXI_STA_TRANS_BUSY BIT(5) > +#define SUNXI_STA_RCV_BUSY BIT(4) > +#define SUNXI_STA_TRANS_OVER BIT(3) > +#define SUNXI_STA_TBUF_RDY BIT(2) > +#define SUNXI_STA_DATA_ORUN BIT(1) > +#define SUNXI_STA_RBUF_RDY BIT(0) > + > +/* interrupt register (r) > + * offset:0x000c default:0x0000_0000 > + */ > +#define SUNXI_INT_BUS_ERR BIT(7) > +#define SUNXI_INT_ARB_LOST BIT(6) > +#define SUNXI_INT_ERR_PASSIVE BIT(5) > +#define SUNXI_INT_WAKEUP BIT(4) > +#define SUNXI_INT_DATA_OR BIT(3) > +#define SUNXI_INT_ERR_WRN BIT(2) > +#define SUNXI_INT_TBUF_VLD BIT(1) > +#define SUNXI_INT_RBUF_VLD BIT(0) > + > +/* interrupt enable register (r/w) > + * offset:0x0010 default:0x0000_0000 > + */ > +#define SUNXI_INTEN_BERR BIT(7) > +#define SUNXI_INTEN_ARB_LOST BIT(6) > +#define SUNXI_INTEN_ERR_PASSIVE BIT(5) > +#define SUNXI_INTEN_WAKEUP BIT(4) > +#define SUNXI_INTEN_OR BIT(3) > +#define SUNXI_INTEN_ERR_WRN BIT(2) > +#define SUNXI_INTEN_TX BIT(1) > +#define SUNXI_INTEN_RX BIT(0) > + > +/* error code */ > +#define SUNXI_ERR_INRCV (0x1 << 5) > +#define SUNXI_ERR_INTRANS (0x0 << 5) > + > +/* filter mode */ > +#define SINXI_FILTER_CLOSE 0 > +#define SUNXI_SINGLE_FLTER_MODE 1 > +#define SUNXI_DUAL_FILTER_MODE 2 > + > +/* message buffer flags */ > +#define SUNXI_MSG_EFF_FLAG BIT(7) > +#define SUNXI_MSG_RTR_FLAG BIT(6) > + > +/* max. number of interrupts handled in ISR */ > +#define SUNXI_CAN_MAX_IRQ 20 > +#define SUNXI_MODE_MAX_RETRIES 100 > + > +struct sunxican_priv { > + struct can_priv can; > + void __iomem *base; > + struct clk *clk; > + spinlock_t cmdreg_lock; /* lock for concurrent cmd register writes */ > +}; > + > +static const struct can_bittiming_const sunxican_bittiming_const = { > + .name = DRV_NAME, > + .tseg1_min = 1, > + .tseg1_max = 16, > + .tseg2_min = 1, > + .tseg2_max = 8, > + .sjw_max = 4, > + .brp_min = 1, > + .brp_max = 64, > + .brp_inc = 1, > +}; > + > +static void sunxi_can_write_cmdreg(struct sunxican_priv *priv, u8 val) > +{ > + unsigned long flags; > + > + spin_lock_irqsave(&priv->cmdreg_lock, flags); > + writel(val, priv->base + SUNXI_REG_CMD_ADDR); > + spin_unlock_irqrestore(&priv->cmdreg_lock, flags); > +} > + > +static int set_normal_mode(struct net_device *dev) > +{ > + struct sunxican_priv *priv = netdev_priv(dev); > + int retry = SUNXI_MODE_MAX_RETRIES; > + u32 mod_reg_val = 0; > + > + do { > + mod_reg_val = readl(priv->base + SUNXI_REG_MSEL_ADDR); > + mod_reg_val &= ~SUNXI_MSEL_RESET_MODE; > + writel(mod_reg_val, priv->base + SUNXI_REG_MSEL_ADDR); > + } while (retry-- && (mod_reg_val & SUNXI_MSEL_RESET_MODE)); > + > + if (readl(priv->base + SUNXI_REG_MSEL_ADDR) & SUNXI_MSEL_RESET_MODE) { > + netdev_err(dev, > + "setting controller into normal mode failed!\n"); > + return -ETIMEDOUT; > + } > + > + priv->can.state = CAN_STATE_ERROR_ACTIVE; > + /* enable interrupts */ > + if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) > + writel(0xFFFF, priv->base + SUNXI_REG_INTEN_ADDR); > + else > + writel(0xFFFF & ~SUNXI_INTEN_BERR, > + priv->base + SUNXI_REG_INTEN_ADDR); > + > + mod_reg_val = readl(priv->base + SUNXI_REG_MSEL_ADDR); > + > + if (priv->can.ctrlmode & CAN_CTRLMODE_PRESUME_ACK) > + mod_reg_val |= SUNXI_MSEL_LOOPBACK_MODE; > + else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) > + mod_reg_val |= SUNXI_MSEL_LISTEN_ONLY_MODE; > + > + writel(mod_reg_val, priv->base + SUNXI_REG_MSEL_ADDR); > + return 0; > +} > + > +static int set_reset_mode(struct net_device *dev) > +{ > + struct sunxican_priv *priv = netdev_priv(dev); > + int retry = SUNXI_MODE_MAX_RETRIES; > + u32 mod_reg_val = 0; > + > + do { > + mod_reg_val = readl(priv->base + SUNXI_REG_MSEL_ADDR); > + mod_reg_val |= SUNXI_MSEL_RESET_MODE; > + writel(mod_reg_val, priv->base + SUNXI_REG_MSEL_ADDR); > + } while (retry-- && !(mod_reg_val & SUNXI_MSEL_RESET_MODE)); > + > + if (!(readl(priv->base + SUNXI_REG_MSEL_ADDR) & > + SUNXI_MSEL_RESET_MODE)) { > + netdev_err(dev, "setting controller into reset mode failed!\n"); > + return -ETIMEDOUT; > + } > + > + priv->can.state = CAN_STATE_STOPPED; > + > + return 0; > +} > + > +static int sunxican_set_bittiming(struct net_device *dev) > +{ > + struct sunxican_priv *priv = netdev_priv(dev); > + struct can_bittiming *bt = &priv->can.bittiming; > + int err; > + u32 cfg; > + > + cfg = ((bt->brp - 1) & 0x3FF) | > + (((bt->sjw - 1) & 0x3) << 14) | > + (((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) << 16) | > + (((bt->phase_seg2 - 1) & 0x7) << 20); > + if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) > + cfg |= 0x800000; > + > + netdev_info(dev, "setting BITTIMING=0x%08x\n", cfg); > + > + /* CAN_BTIME_ADDR only writable in reset mode */ > + err = set_reset_mode(dev); > + if (err) > + return err; > + writel(cfg, priv->base + SUNXI_REG_BTIME_ADDR); > + > + return set_normal_mode(dev); > +} > + > +static int sunxican_get_berr_counter(const struct net_device *dev, > + struct can_berr_counter *bec) > +{ > + struct sunxican_priv *priv = netdev_priv(dev); > + u32 errors; > + int err; > + > + err = clk_prepare_enable(priv->clk); > + if (err) { > + netdev_err(dev, "could not enable clock\n"); > + return err; > + } > + > + errors = readl(priv->base + SUNXI_REG_ERRC_ADDR); > + > + bec->txerr = errors & 0xFF; > + bec->rxerr = (errors >> 16) & 0xFF; > + > + clk_disable_unprepare(priv->clk); > + > + return 0; > +} > + > +static int sunxi_can_start(struct net_device *dev) > +{ > + struct sunxican_priv *priv = netdev_priv(dev); > + int err; > + u32 temp_irqen; > + > + /* turn on clocking for CAN peripheral block */ > + err = clk_prepare_enable(priv->clk); > + if (err) { > + netdev_err(dev, "could not enable clocking (apb1_can)\n"); > + goto exit; > + } > + > + /* leave reset mode */ > + if (priv->can.state != CAN_STATE_STOPPED) > + set_reset_mode(dev); > + > + /* set filters - we accept all */ > + writel(0x00000000, priv->base + SUNXI_REG_ACPC_ADDR); > + writel(0xFFFFFFFF, priv->base + SUNXI_REG_ACPM_ADDR); > + > + /* Clear error counters and error code capture */ > + writel(0x0, priv->base + SUNXI_REG_ERRC_ADDR); > + > + /* enable CAN specific interrupts */ > + temp_irqen = SUNXI_INTEN_BERR | SUNXI_INTEN_ERR_PASSIVE | > + SUNXI_INTEN_OR | SUNXI_INTEN_RX; > + writel(readl(priv->base + SUNXI_REG_INTEN_ADDR) | temp_irqen, > + priv->base + SUNXI_REG_INTEN_ADDR); > + > + err = sunxican_set_bittiming(dev); > + > + if (err) > + return err; You're leaving the clock enabled if you have an error. > + > + return 0; > + > +exit: > + return err; > +} > + > +static int sunxican_set_mode(struct net_device *dev, enum can_mode mode) > +{ > + int err; > + > + switch (mode) { > + case CAN_MODE_START: > + err = sunxi_can_start(dev); > + if (err) { > + netdev_err(dev, "starting CAN controller failed!\n"); > + return err; > + } > + if (netif_queue_stopped(dev)) > + netif_wake_queue(dev); > + break; > + > + default: > + return -EOPNOTSUPP; > + } > + return 0; > +} > + > +/* transmit a CAN message > + * message layout in the sk_buff should be like this: > + * xx xx xx xx ff ll 00 11 22 33 44 55 66 77 > + * [ can_id ] [flags] [len] [can data (up to 8 bytes] > + */ > +static int sunxican_start_xmit(struct sk_buff *skb, struct net_device *dev) > +{ > + struct sunxican_priv *priv = netdev_priv(dev); > + struct can_frame *cf = (struct can_frame *)skb->data; > + u8 dlc; > + u32 dreg, msg_flag_n; > + canid_t id; > + int i; > + > + if (can_dropped_invalid_skb(dev, skb)) > + return NETDEV_TX_OK; > + > + netif_stop_queue(dev); > + > + id = cf->can_id; > + dlc = cf->can_dlc; > + msg_flag_n = dlc; > + > + if (id & CAN_RTR_FLAG) > + msg_flag_n |= SUNXI_MSG_RTR_FLAG; > + > + if (id & CAN_EFF_FLAG) { > + msg_flag_n |= SUNXI_MSG_EFF_FLAG; > + dreg = SUNXI_REG_BUF5_ADDR; > + writel((id >> 21) & 0xFF, priv->base + SUNXI_REG_BUF1_ADDR); > + writel((id >> 13) & 0xFF, priv->base + SUNXI_REG_BUF2_ADDR); > + writel((id >> 5) & 0xFF, priv->base + SUNXI_REG_BUF3_ADDR); > + writel((id << 3) & 0xF8, priv->base + SUNXI_REG_BUF4_ADDR); > + } else { > + dreg = SUNXI_REG_BUF3_ADDR; > + writel((id >> 3) & 0xFF, priv->base + SUNXI_REG_BUF1_ADDR); > + writel((id << 5) & 0xE0, priv->base + SUNXI_REG_BUF2_ADDR); > + } > + > + for (i = 0; i < dlc; i++) > + writel(cf->data[i], priv->base + (dreg + i * 4)); > + > + writel(msg_flag_n, priv->base + SUNXI_REG_BUF0_ADDR); > + > + can_put_echo_skb(skb, dev, 0); > + > + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) > + sunxi_can_write_cmdreg(priv, SUNXI_CMD_SELF_RCV_REQ); > + else > + sunxi_can_write_cmdreg(priv, SUNXI_CMD_TRANS_REQ); > + > + return NETDEV_TX_OK; > +} > + > +static void sunxi_can_rx(struct net_device *dev) > +{ > + struct sunxican_priv *priv = netdev_priv(dev); > + struct net_device_stats *stats = &dev->stats; > + struct can_frame *cf; > + struct sk_buff *skb; > + u8 fi; > + u32 dreg; > + canid_t id; > + int i; > + > + /* create zero'ed CAN frame buffer */ > + skb = alloc_can_skb(dev, &cf); > + if (!skb) > + return; > + > + fi = readl(priv->base + SUNXI_REG_BUF0_ADDR); > + cf->can_dlc = get_can_dlc(fi & 0x0F); > + if (fi & SUNXI_MSG_EFF_FLAG) { > + dreg = SUNXI_REG_BUF5_ADDR; > + id = (readl(priv->base + SUNXI_REG_BUF1_ADDR) << 21) | > + (readl(priv->base + SUNXI_REG_BUF2_ADDR) << 13) | > + (readl(priv->base + SUNXI_REG_BUF3_ADDR) << 5) | > + ((readl(priv->base + SUNXI_REG_BUF4_ADDR) >> 3) & 0x1f); > + id |= CAN_EFF_FLAG; > + } else { > + dreg = SUNXI_REG_BUF3_ADDR; > + id = (readl(priv->base + SUNXI_REG_BUF1_ADDR) << 3) | > + ((readl(priv->base + SUNXI_REG_BUF2_ADDR) >> 5) & 0x7); > + } > + > + /* remote frame ? */ > + if (fi & SUNXI_MSG_RTR_FLAG) > + id |= CAN_RTR_FLAG; > + else > + for (i = 0; i < cf->can_dlc; i++) > + cf->data[i] = readl(priv->base + dreg + i * 4); > + > + cf->can_id = id; > + > + sunxi_can_write_cmdreg(priv, SUNXI_CMD_RELEASE_RBUF); > + > + stats->rx_packets++; > + stats->rx_bytes += cf->can_dlc; > + netif_rx(skb); > + > + can_led_event(dev, CAN_LED_EVENT_RX); > +} > + > +static int sunxi_can_err(struct net_device *dev, u8 isrc, u8 status) > +{ > + struct sunxican_priv *priv = netdev_priv(dev); > + struct net_device_stats *stats = &dev->stats; > + struct can_frame *cf; > + struct sk_buff *skb; > + enum can_state state = priv->can.state; > + enum can_state rx_state, tx_state; > + unsigned int rxerr, txerr, errc; > + u32 ecc, alc; > + > + skb = alloc_can_err_skb(dev, &cf); > + if (!skb) > + return -ENOMEM; > + > + errc = readl(priv->base + SUNXI_REG_ERRC_ADDR); > + rxerr = (errc >> 16) & 0xFF; > + txerr = errc & 0xFF; > + > + cf->data[6] = txerr; > + cf->data[7] = rxerr; > + > + if (isrc & SUNXI_INT_DATA_OR) { > + /* data overrun interrupt */ > + netdev_dbg(dev, "data overrun interrupt\n"); > + cf->can_id |= CAN_ERR_CRTL; > + cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; > + stats->rx_over_errors++; > + stats->rx_errors++; > + /* clear bit */ > + sunxi_can_write_cmdreg(priv, SUNXI_CMD_CLEAR_OR_FLAG); > + } > + if (isrc & SUNXI_INT_ERR_WRN) { > + /* error warning interrupt */ > + netdev_dbg(dev, "error warning interrupt\n"); > + > + if (status & SUNXI_STA_BUS_OFF) > + state = CAN_STATE_BUS_OFF; > + else if (status & SUNXI_STA_ERR_STA) > + state = CAN_STATE_ERROR_WARNING; > + else > + state = CAN_STATE_ERROR_ACTIVE; > + } > + if (isrc & SUNXI_INT_BUS_ERR) { > + /* bus error interrupt */ > + netdev_dbg(dev, "bus error interrupt\n"); > + priv->can.can_stats.bus_error++; > + stats->rx_errors++; > + > + ecc = readl(priv->base + SUNXI_REG_STA_ADDR); > + > + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; > + > + switch (ecc & SUNXI_STA_MASK_ERR) { > + case SUNXI_STA_BIT_ERR: > + cf->data[2] |= CAN_ERR_PROT_BIT; > + break; > + case SUNXI_STA_FORM_ERR: > + cf->data[2] |= CAN_ERR_PROT_FORM; > + break; > + case SUNXI_STA_STUFF_ERR: > + cf->data[2] |= CAN_ERR_PROT_STUFF; > + break; > + default: > + cf->data[2] |= CAN_ERR_PROT_UNSPEC; > + cf->data[3] = (ecc & SUNXI_STA_ERR_SEG_CODE) >> 16; > + break; > + } > + /* error occurred during transmission? */ > + if ((ecc & SUNXI_STA_ERR_DIR) == 0) > + cf->data[2] |= CAN_ERR_PROT_TX; > + } > + if (isrc & SUNXI_INT_ERR_PASSIVE) { > + /* error passive interrupt */ > + netdev_dbg(dev, "error passive interrupt\n"); > + if (state == CAN_STATE_ERROR_PASSIVE) > + state = CAN_STATE_ERROR_WARNING; > + else > + state = CAN_STATE_ERROR_PASSIVE; > + } > + if (isrc & SUNXI_INT_ARB_LOST) { > + /* arbitration lost interrupt */ > + netdev_dbg(dev, "arbitration lost interrupt\n"); > + alc = readl(priv->base + SUNXI_REG_STA_ADDR); > + priv->can.can_stats.arbitration_lost++; > + stats->tx_errors++; > + cf->can_id |= CAN_ERR_LOSTARB; > + cf->data[0] = (alc & 0x1f) >> 8; > + } > + > + if (state != priv->can.state) { > + tx_state = txerr >= rxerr ? state : 0; > + rx_state = txerr <= rxerr ? state : 0; > + > + can_change_state(dev, cf, tx_state, rx_state); > + if (state == CAN_STATE_BUS_OFF) > + can_bus_off(dev); > + } > + > + stats->rx_packets++; > + stats->rx_bytes += cf->can_dlc; > + netif_rx(skb); > + > + return 0; > +} > + > +static irqreturn_t sunxi_can_interrupt(int irq, void *dev_id) > +{ > + struct net_device *dev = (struct net_device *)dev_id; > + struct sunxican_priv *priv = netdev_priv(dev); > + struct net_device_stats *stats = &dev->stats; > + u8 isrc, status; > + int n = 0; > + > + while ((isrc = readl(priv->base + SUNXI_REG_INT_ADDR)) && > + (n < SUNXI_CAN_MAX_IRQ)) { > + n++; > + status = readl(priv->base + SUNXI_REG_STA_ADDR); > + > + if (isrc & SUNXI_INT_WAKEUP) > + netdev_warn(dev, "wakeup interrupt\n"); > + > + if (isrc & SUNXI_INT_TBUF_VLD) { > + /* transmission complete interrupt */ > + stats->tx_bytes += > + readl(priv->base + > + SUNXI_REG_RBUF_RBACK_START_ADDR) & 0xf; > + stats->tx_packets++; > + can_get_echo_skb(dev, 0); > + netif_wake_queue(dev); > + can_led_event(dev, CAN_LED_EVENT_TX); > + } > + if (isrc & SUNXI_INT_RBUF_VLD) { > + /* receive interrupt */ > + while (status & SUNXI_STA_RBUF_RDY) { > + /* RX buffer is not empty */ > + sunxi_can_rx(dev); > + status = readl(priv->base + SUNXI_REG_STA_ADDR); > + } > + } > + if (isrc & > + (SUNXI_INT_DATA_OR | SUNXI_INT_ERR_WRN | SUNXI_INT_BUS_ERR | > + SUNXI_INT_ERR_PASSIVE | SUNXI_INT_ARB_LOST)) { > + /* error interrupt */ > + if (sunxi_can_err(dev, isrc, status)) > + break; > + } > + /* clear interrupts */ > + writel(isrc, priv->base + SUNXI_REG_INT_ADDR); > + readl(priv->base + SUNXI_REG_INT_ADDR); > + } Why not simply handle whatever you have in the status register, and let the interrupt retrigger if there's something new? > + if (n >= SUNXI_CAN_MAX_IRQ) > + netdev_dbg(dev, "%d messages handled in ISR", n); > + > + return (n) ? IRQ_HANDLED : IRQ_NONE; > +} > + > +static int sunxican_open(struct net_device *dev) > +{ > + int err; > + > + /* common open */ > + err = open_candev(dev); > + if (err) > + return err; > + > + /* register interrupt handler */ > + err = request_irq(dev->irq, sunxi_can_interrupt, IRQF_SHARED, > + dev->name, dev); > + if (err) { > + netdev_err(dev, "request_irq err: %d\n", err); > + close_candev(dev); > + return -EAGAIN; > + } > + > + sunxi_can_start(dev); > + > + can_led_event(dev, CAN_LED_EVENT_OPEN); > + > + netif_start_queue(dev); > + > + return 0; > +} > + > +static int sunxican_close(struct net_device *dev) > +{ > + struct sunxican_priv *priv = netdev_priv(dev); > + > + netif_stop_queue(dev); > + set_reset_mode(dev); > + clk_disable_unprepare(priv->clk); Are you sure you have the right use count on that clock? You're calling sunxi_can_start from several places, but you call clk_disable_unprepare only from here. Even if it does start, it is really confusing. Please move the clk_prepare_enable in the open function. > + > + free_irq(dev->irq, dev); > + close_candev(dev); > + can_led_event(dev, CAN_LED_EVENT_STOP); > + > + return 0; > +} > + > +static const struct net_device_ops sunxican_netdev_ops = { > + .ndo_open = sunxican_open, > + .ndo_stop = sunxican_close, > + .ndo_start_xmit = sunxican_start_xmit, > +}; > + > +static const struct of_device_id sunxican_of_match[] = { > + {.compatible = "allwinner,sunxican"}, > + {}, > +}; > + > +MODULE_DEVICE_TABLE(of, sunxican_of_match); > + > +static int sunxican_remove(struct platform_device *pdev) > +{ > + struct net_device *dev = platform_get_drvdata(pdev); > + > + unregister_netdev(dev); > + free_candev(dev); > + > + return 0; > +} > + > +static int sunxican_probe(struct platform_device *pdev) > +{ > + struct resource *mem; > + struct clk *clk; > + void __iomem *addr; > + int err, irq; > + struct net_device *dev; > + struct sunxican_priv *priv; > + > + clk = devm_clk_get(&pdev->dev, "apb1_can"); If you pass NULL, it will automatically grab the first clock in the DT, which is what you want here, otherwise the clocks property is useless. > + if (IS_ERR(clk)) { > + dev_err(&pdev->dev, "no clock defined\n"); > + err = -ENODEV; > + goto exit; > + } > + > + irq = platform_get_irq(pdev, 0); > + if (irq < 0) { > + dev_err(&pdev->dev, "could not get a valid irq\n"); > + err = -ENODEV; > + goto exit; > + } > + > + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + addr = devm_ioremap_resource(&pdev->dev, mem); > + if (IS_ERR(addr)) { > + err = -EBUSY; > + goto exit; > + } > + > + dev = alloc_candev(sizeof(struct sunxican_priv), 1); > + if (!dev) { > + dev_err(&pdev->dev, > + "could not allocate memory for CAN device\n"); > + err = -ENOMEM; > + goto exit; > + } > + > + dev->netdev_ops = &sunxican_netdev_ops; > + dev->irq = irq; > + dev->flags |= IFF_ECHO; > + > + priv = netdev_priv(dev); > + priv->can.clock.freq = clk_get_rate(clk); > + priv->can.bittiming_const = &sunxican_bittiming_const; > + priv->can.do_set_mode = sunxican_set_mode; > + priv->can.do_get_berr_counter = sunxican_get_berr_counter; > + priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING | > + CAN_CTRLMODE_LISTENONLY | > + CAN_CTRLMODE_LOOPBACK | > + CAN_CTRLMODE_3_SAMPLES; > + priv->base = addr; > + priv->clk = clk; > + spin_lock_init(&priv->cmdreg_lock); > + > + platform_set_drvdata(pdev, dev); > + SET_NETDEV_DEV(dev, &pdev->dev); > + > + err = register_candev(dev); > + if (err) { > + dev_err(&pdev->dev, "registering %s failed (err=%d)\n", > + DRV_NAME, err); > + goto exit_free; > + } > + devm_can_led_init(dev); > + > + dev_info(&pdev->dev, "device registered (base=%p, irq=%d)\n", > + priv->base, dev->irq); > + > + return 0; > + > +exit_free: > + free_candev(dev); > +exit: > + return err; > +} > + > +static int __maybe_unused sunxi_can_suspend(struct device *device) > +{ > + struct net_device *dev = dev_get_drvdata(device); > + struct sunxican_priv *priv = netdev_priv(dev); > + u32 mode; > + int err; > + > + if (netif_running(dev)) { > + netif_stop_queue(dev); > + netif_device_detach(dev); > + } > + > + err = set_reset_mode(dev); > + if (err) > + return err; > + > + mode = readl(priv->base + SUNXI_REG_MSEL_ADDR); > + writel(mode | SUNXI_MSEL_SLEEP_MODE, priv->base + SUNXI_REG_MSEL_ADDR); > + > + priv->can.state = CAN_STATE_SLEEPING; > + > + clk_disable(priv->clk); > + return 0; > +} > + > +static int __maybe_unused sunxi_can_resume(struct device *device) > +{ > + struct net_device *dev = dev_get_drvdata(device); > + struct sunxican_priv *priv = netdev_priv(dev); > + u32 mode; > + int err; > + > + err = clk_enable(priv->clk); > + if (err) { > + netdev_err(dev, "clk_enable() failed, error %d\n", err); > + return err; > + } > + > + err = set_reset_mode(dev); > + if (err) > + return err; > + > + mode = readl(priv->base + SUNXI_REG_MSEL_ADDR); > + writel(mode & ~(SUNXI_MSEL_SLEEP_MODE), > + priv->base + SUNXI_REG_MSEL_ADDR); > + err = set_normal_mode(dev); > + if (err) > + return err; > + > + priv->can.state = CAN_STATE_ERROR_ACTIVE; > + if (netif_running(dev)) { > + netif_device_attach(dev); > + netif_start_queue(dev); > + } > + return 0; > +} > + > +static SIMPLE_DEV_PM_OPS(sunxi_can_pm_ops, sunxi_can_suspend, sunxi_can_resume); How did you test those hooks? There's no suspend support yet. > +static struct platform_driver sunxi_can_driver = { > + .driver = { > + .name = DRV_NAME, > + .pm = &sunxi_can_pm_ops, > + .of_match_table = sunxican_of_match, > + }, > + .probe = sunxican_probe, > + .remove = sunxican_remove, > +}; > + > +module_platform_driver(sunxi_can_driver); > + > +MODULE_AUTHOR("Peter Chen "); > +MODULE_AUTHOR("Gerhard Bertelsmann "); > +MODULE_LICENSE("Dual BSD/GPL"); > +MODULE_DESCRIPTION(DRV_NAME "CAN driver for Allwinner SoCs (A10/A20)"); > +MODULE_VERSION(DRV_MODULE_VERSION); Is this going to be useful? The module version is already redundant with the kernel version, and there's a good chance it will never reach 1.0. Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --R0KbGFzrRdaLlFh/--