On 1/12/21 2:05 PM, Vincent Mailhol wrote: > This driver supports the ES581.4, ES582.1 and ES584.1 interfaces from > ETAS GmbH (https://www.etas.com/en/products/es58x.php). > > Co-developed-by: Arunachalam Santhanam <arunachalam.santhanam@xxxxxxxxxxxx> > Signed-off-by: Arunachalam Santhanam <arunachalam.santhanam@xxxxxxxxxxxx> > Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx> [...] > diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.c b/drivers/net/can/usb/etas_es58x/es58x_core.c > new file mode 100644 > index 000000000000..30692d78d8e6 > --- /dev/null > +++ b/drivers/net/can/usb/etas_es58x/es58x_core.c > @@ -0,0 +1,2589 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +/* Driver for ETAS GmbH ES58X USB CAN(-FD) Bus Interfaces. > + * > + * File es58x_core.c: Core logic to manage the network devices and the > + * USB interface. > + * > + * Copyright (C) 2019 Robert Bosch Engineering and Business > + * Solutions. All rights reserved. > + * Copyright (C) 2020 ETAS K.K.. All rights reserved. > + */ > + > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/moduleparam.h> > +#include <linux/usb.h> > +#include <linux/crc16.h> > +#include <linux/spinlock.h> > +#include <asm/unaligned.h> > + > +#include "es58x_core.h" > + > +#define DRV_VERSION "1.00" > +MODULE_AUTHOR("Mailhol Vincent <mailhol.vincent@xxxxxxxxxx>"); > +MODULE_AUTHOR("Arunachalam Santhanam <arunachalam.santhanam@xxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Socket CAN driver for ETAS ES58X USB adapters"); > +MODULE_VERSION(DRV_VERSION); > +MODULE_LICENSE("GPL v2"); > + > +/* Vendor and product id */ > +#define ES58X_MODULE_NAME "etas_es58x" > +#define ES58X_VENDOR_ID 0x108C > +#define ES581_4_PRODUCT_ID 0x0159 > +#define ES582_1_PRODUCT_ID 0x0168 > +#define ES584_1_PRODUCT_ID 0x0169 > + > +/* Table of devices which work with this driver */ > +static const struct usb_device_id es58x_id_table[] = { > + {USB_DEVICE(ES58X_VENDOR_ID, ES581_4_PRODUCT_ID)}, > + {USB_DEVICE(ES58X_VENDOR_ID, ES582_1_PRODUCT_ID)}, > + {USB_DEVICE(ES58X_VENDOR_ID, ES584_1_PRODUCT_ID)}, > + {} /* Terminating entry */ > +}; > + > +MODULE_DEVICE_TABLE(usb, es58x_id_table); > + > +#define es58x_print_hex_dump(buf, len) \ > + print_hex_dump(KERN_DEBUG, \ > + ES58X_MODULE_NAME " " __stringify(buf) ": ", \ > + DUMP_PREFIX_NONE, 16, 1, buf, len, false) > + > +#define es58x_print_hex_dump_debug(buf, len) \ > + print_hex_dump_debug(ES58X_MODULE_NAME " " __stringify(buf) ": ",\ > + DUMP_PREFIX_NONE, 16, 1, buf, len, false) > + > +/* The last two bytes of an ES58X command is a CRC16. The first two > + * bytes (the start of frame) are skipped and the CRC calculation > + * starts on the third byte. > + */ > +#define ES58X_CRC_CALC_OFFSET 2 > + > +/** > + * es58x_calculate_crc() - Compute the crc16 of a given URB. > + * @urb_cmd: The URB command for which we want to calculate the CRC. > + * @urb_len: Length of @urb_cmd. Must be at least bigger than 4 > + * (ES58X_CRC_CALC_OFFSET + sizeof(crc)) > + * > + * Return: crc16 value. > + */ > +static u16 es58x_calculate_crc(const union es58x_urb_cmd *urb_cmd, u16 urb_len) > +{ > + u16 crc; > + ssize_t len = urb_len - ES58X_CRC_CALC_OFFSET - sizeof(crc); > + > + WARN_ON(len < 0); Is it possible to ensure earlier, that the urbs are of correct length? > + crc = crc16(0, &urb_cmd->raw_cmd[ES58X_CRC_CALC_OFFSET], len); > + return crc; > +} [...] > +/** > + * struct es58x_priv - All information specific to a CAN channel. > + * @can: struct can_priv must be the first member (Socket CAN relies > + * on the fact that function netdev_priv() returns a pointer to > + * a struct can_priv). > + * @es58x_dev: pointer to the corresponding ES58X device. > + * @tx_urb: Used as a buffer to concatenate the TX messages and to do > + * a bulk send. Please refer to es58x_start_xmit() for more > + * details. > + * @echo_skb_spinlock: Spinlock to protect the access to the echo skb > + * FIFO. > + * @current_packet_idx: Keeps track of the packet indexes. > + * @echo_skb_tail_idx: beginning of the echo skb FIFO, i.e. index of > + * the first element. > + * @echo_skb_head_idx: end of the echo skb FIFO plus one, i.e. first > + * free index. > + * @num_echo_skb: actual number of elements in the FIFO. Thus, the end > + * of the FIFO is echo_skb_head = (echo_skb_tail_idx + > + * num_echo_skb) % can.echo_skb_max. > + * @tx_total_frame_len: sum, in bytes, of the length of each of the > + * CAN messages contained in @tx_urb. To be used as an input of > + * netdev_sent_queue() for BQL. > + * @tx_can_msg_cnt: Number of messages in @tx_urb. > + * @tx_can_msg_is_fd: false: all messages in @tx_urb are Classical > + * CAN, true: all messages in @tx_urb are CAN FD. Rationale: > + * ES58X FD devices do not allow to mix Classical CAN and FD CAN > + * frames in one single bulk transmission. > + * @err_passive_before_rtx_success: The ES58X device might enter in a > + * state in which it keeps alternating between error passive > + * and active state. This counter keeps track of the number of > + * error passive and if it gets bigger than > + * ES58X_CONSECUTIVE_ERR_PASSIVE_MAX, es58x_rx_err_msg() will > + * force the status to bus-off. > + * @channel_idx: Channel index, starts at zero. > + */ > +struct es58x_priv { > + struct can_priv can; > + struct es58x_device *es58x_dev; > + struct urb *tx_urb; > + > + spinlock_t echo_skb_spinlock; /* Comments: c.f. supra */ > + u32 current_packet_idx; > + u16 echo_skb_tail_idx; > + u16 echo_skb_head_idx; > + u16 num_echo_skb; Can you explain me how the tx-path works, especially why you need the current_packet_idx. In the mcp251xfd driver, the number of TX buffers is a power of two, that makes things easier. tx_heads % len points to the next buffer to be filled, tx_tail % len points to the next buffer to be completed. tx_head - tx_tail is the fill level of the FIFO. This works without spinlocks. > + > + u16 tx_total_frame_len; > + u8 tx_can_msg_cnt; > + bool tx_can_msg_is_fd; > + > + u8 err_passive_before_rtx_success; > + > + u8 channel_idx; > +}; Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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