From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 512CE357D13 for ; Wed, 9 Sep 2026 09:49:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788947350; cv=none; b=TFEuS0slmt2IWMnVznxFM2VRzVCagrxtOpENar+GYztIax7N7SA9WYwRabNDZYjaQIq78s/ZTsYFc7P7VLdANhWP/c5Sr2P4DObN790v+b+r+9Uhh2AqiqQP1sIodWEoO6tI6LZ2VZvBKGJWKmiEHZD+xIH7AJhM4BVnI8rRM7A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788947350; c=relaxed/simple; bh=oXS6o8DVkv9uOwR/uLXHdsxvJOPAczWZwvpwIVpDKZ0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=YooKzZgeIkuxUXx/sMI4oodD5Gydqk4Y6B2MpWkmYuZRS3loxfaqWbog075reCFUm9KdXdYNkDZON1Y6QpYM55yn9IWRZXjOjAnevidocPMy16qMPXrcFiNDRkQKojoy7xp6iGXn29m4MgX8L3+6ZmGQlaLnkW+JZsyAeni0Lpc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [223.64.69.112]) by gateway (Coremail) with SMTP id _____8DxUNGRK6FqVyIKAA--.29239S3; Wed, 09 Sep 2026 17:49:05 +0800 (CST) Received: from kernelserver (unknown [223.64.69.112]) by front1 (Coremail) with SMTP id qMiowJBxJs2NK6Fq8d4dAA--.22524S2; Wed, 09 Sep 2026 17:49:02 +0800 (CST) From: Binbin Zhou To: Binbin Zhou , Huacai Chen , Marc Kleine-Budde , Vincent Mailhol , Bingxiong Li Cc: Huacai Chen , linux-can@vger.kernel.org, jeffbai@aosc.io, Binbin Zhou Subject: [PATCH v8 0/2] Add Loongson CAN-FD controller driver Date: Wed, 9 Sep 2026 17:48:52 +0800 Message-ID: X-Mailer: git-send-email 2.52.0 Precedence: bulk X-Mailing-List: linux-can@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:qMiowJBxJs2NK6Fq8d4dAA--.22524S2 X-CM-SenderInfo: p2kr3uplqex0o6or00hjvr0hdfq/1tbiAgEFCGqgznYGWwAAsh X-Coremail-Antispam: 1Uk129KBj93XoW3WFyfCFy7Zry7XFW7Jw17twc_yoW7ArW7pF W5C3srur1DKr48Zrs3JayrCF15Aa1rJr1fWFZxAw109as8Zw12g3ySk3W5WrWUurZ5CF1I vrWruFW0kas8CFcCm3ZEXasCq-sJn29KB7ZKAUJUUUU5529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUkFb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Jr0_JF4l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Jr0_Gr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AK xVW8Jr0_Cr1UM2AIxVAIcxkEcVAq07x20xvEncxIr21l57IF6xkI12xvs2x26I8E6xACxx 1l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1Y6r17McIj6I8E87Iv 67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41l42xK82IYc2 Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s02 6x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0x vE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r1j6r4UMIIF0xvE 42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6x kF7I0E14v26r1j6r4UYxBIdaVFxhVjvjDU0xZFpf9x07j1WlkUUUUU= Hi all: This patchset adds support for the CAN-FD controller found on Loongson CPUs. Patch 1 introduces the basic CAN-FD controller driver with support for classic CAN and CAN FD, including bit timing, error handling, NAPI-based RX, and multiple TX buffers. Patch 2 adds optional DMA support for RX path using the Loongson APB CMC DMA engine, which significantly reduces CPU load under high receive throughput. The driver has been tested on Loongson-2K3000 platforms with various CAN/CAN FD traffic patterns. Finally, I'd like to thank Bingxiong, the original author of this driver, for his efforts in working on the patch. Thanks. Binbin ========= V8: Patch (1/2): - Use local copy of can_bittiming in set_btr to avoid corrupting persistent structure; - Fix endianness and strict aliasing in TX/RX data paths; - Fixed spelling errors; Patch (2/2): - Add overflow detection for RXDMA; - Simplified callback function names Link to V7: https://lore.kernel.org/all/cover.1785898181.git.zhoubinbin@loongson.cn/ V7: Patch (1/2): - Fix can_bittiming_const->tseg1_max; - Fix TX buffer id in loongson_canfd_start_xmit(); - Add rwcnt checking in loongson_canfd_rx() - Add netdev stats spinlock; - Add net_ratelimit() to control log output in loongson_canfd_err_interrupt); - Rewrite `loongson_canfd_rx_napi()` to clearly distinguish between the two scenarios: "no more data to process" and "quota exhausted". Patch (2/2): - Put dmaengine_terminate_sync() before loongson_canfd_rxdma_free(); Link to V6: https://lore.kernel.org/all/cover.1784597141.git.zhoubinbin@loongson.cn/ V6: - Rebase on linux-can/master; Patch (1/2): - Drop CAN_CTRLMODE_3_SAMPLES ctrlmode; - Replace kfree_skb() with dev_kfree_skb_any(); - Drop REG_CMD_ERCRST operation; - Rewrite `loongson_canfd_tx_interrupt()` to prevent duplicate handling of TX completion'; Patch (2/2): - Added a fallback to true when dmaengine_tx_status() returns an error; - Replaced all direct regmap_read() from LOONGSON_CANFD_RX_DATA with the priv->get_rx_data() callback; - Release the DMA channel and clear priv->rx_ch on dma_alloc_coherent() failure; Link to V5: https://lore.kernel.org/all/cover.1783670733.git.zhoubinbin@loongson.cn/ V5: Patch (1/2): - Fix tseg1_max const value; - Empty FIFO when SKB allocate failed. - Use REG_FRAME_META1_RWCNT as the playload read count value; - Only clean processed interrupt flags in loongson_canfd_err_interrupt(); - Refact loongson_canfd_tx_interrupt(); - Add LOONGSON_CANFD_TRV_DLY into loongson_canfd_volatile_reg(); Patch (2/2): - Fix dma_request_chan() error path; - Fix build error; - Fix loongson_canfd_rxdma_init() error path; Link to V4: https://lore.kernel.org/all/cover.1783391759.git.zhoubinbin@loongson.cn/ V4: - Fix some issues from sashiko. Patch (1/2): - Update commit message; - Use common APIs to calculate DLC; - Correct CAN_RTR_FLAG judgement; - Add skb check for CAN_STATE_ERROR_ACTIVE case; - Use regmap_write() rather than regmap_update_bits() to disable all interrupts; - Add napi_disable() in error paths; - Add `clock-frequency` return value check; - More comments for macros. Link to V3: https://lore.kernel.org/all/cover.1782787997.git.zhoubinbin@loongson.cn/ V3: Patch (1/2): - Replace the switch-case statement with a calculated mask in `loongson_canfd_get_txbuf_sts()`; - Change `loongson_canfd_reset()` return type to `void`; - Drop old code in `loongson_canfd_set_btr()`; - Rename `loongson_canfd_set_mode()` to `loongson_canfd_set_conf_mode()`; - Drop `cf->__res*` usage; - Drop unnecessary macro definitions; - Add `netif_napi_del()` in probe error route path; - Replace ternary operator with `if-else`; - Drop stats->rx_packets and stats->rx_bytes count in CAN error frames; - Add ethtool_ops; - Add CAN_CTRLMODE_CC_LEN8_DLC; Patch (2/2): - Fix W=2 warning; - Rename get_rx_frc() -> get_rxbuf_empty(); - Put `loongson_canfd_rxdma_remove()` before free_candev(); - Adjust the RXDMA probe process. Link to V2: https://lore.kernel.org/all/cover.1780908445.git.zhoubinbin@loongson.cn/ V2: Patch (1/2): - Put all code into one file; - Add COMPILE_TEST Kconfig option; - Rewrite Kconfig description; - Use `regmap_test_bits()` to simplify bit field checks; - Drop odd FIELD_GET() usage; - Don't use FIELD_GET() for a single bit; - Use an if/else instead of the ternary operator; - Use the CAN TDC framework to get the SSP value; - Use guard(spinlock)/scoped_guard(spinlock); - Use netdev_debug() to be less verboss; - Check for memory allocation failure; - Add CAN_ERR_CNT flag; - Drop unused REG_DATA_xx_yy_W_DATA_yy definition; - Add more function comment; Link to V1: https://lore.kernel.org/all/cover.1777273055.git.zhoubinbin@loongson.cn/ Binbin Zhou (2): can: Add Loongson CAN-FD controller driver can: loongson_canfd: Add RXDMA support MAINTAINERS | 7 + drivers/net/can/Kconfig | 11 + drivers/net/can/Makefile | 1 + drivers/net/can/loongson_canfd.c | 1829 ++++++++++++++++++++++++++++++ 4 files changed, 1848 insertions(+) create mode 100644 drivers/net/can/loongson_canfd.c base-commit: dc4b95b8fee95113587e93ca116356032d271371 -- 2.52.0