path: root/drivers/net/can/usb/peak_usb/pcan_usb_core.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * CAN driver for PEAK System USB adapters
 * Derived from the PCAN project file driver/src/pcan_usb_core.c
 *
 * Copyright (C) 2003-2010 PEAK System-Technik GmbH
 * Copyright (C) 2010-2012 Stephane Grosjean <s.grosjean@peak-system.com>
 *
 * Many thanks to Klaus Hitschler <klaus.hitschler@gmx.de>
 */
#include <linux/device.h>
#include <linux/ethtool.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/signal.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/usb.h>

#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>

#include "pcan_usb_core.h"

MODULE_AUTHOR("Stephane Grosjean <s.grosjean@peak-system.com>");
MODULE_DESCRIPTION("CAN driver for PEAK-System USB adapters");
MODULE_LICENSE("GPL v2");

/* Table of devices that work with this driver */
static const struct usb_device_id peak_usb_table[] = {
	{
		USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USB_PRODUCT_ID),
		.driver_info = (kernel_ulong_t)&pcan_usb,
	}, {
		USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBPRO_PRODUCT_ID),
		.driver_info = (kernel_ulong_t)&pcan_usb_pro,
	}, {
		USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBFD_PRODUCT_ID),
		.driver_info = (kernel_ulong_t)&pcan_usb_fd,
	}, {
		USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBPROFD_PRODUCT_ID),
		.driver_info = (kernel_ulong_t)&pcan_usb_pro_fd,
	}, {
		USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBCHIP_PRODUCT_ID),
		.driver_info = (kernel_ulong_t)&pcan_usb_chip,
	}, {
		USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBX6_PRODUCT_ID),
		.driver_info = (kernel_ulong_t)&pcan_usb_x6,
	}, {
		/* Terminating entry */
	}
};

MODULE_DEVICE_TABLE(usb, peak_usb_table);

static ssize_t can_channel_id_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct net_device *netdev = to_net_dev(dev);
	struct peak_usb_device *peak_dev = netdev_priv(netdev);

	return sysfs_emit(buf, "%08X\n", peak_dev->can_channel_id);
}
static DEVICE_ATTR_RO(can_channel_id);

/* mutable to avoid cast in attribute_group */
static struct attribute *peak_usb_sysfs_attrs[] = {
	&dev_attr_can_channel_id.attr,
	NULL,
};

static const struct attribute_group peak_usb_sysfs_group = {
	.name	= "peak_usb",
	.attrs	= peak_usb_sysfs_attrs,
};

/*
 * dump memory
 */
#define DUMP_WIDTH	16
void pcan_dump_mem(const char *prompt, const void *p, int l)
{
	pr_info("%s dumping %s (%d bytes):\n",
		PCAN_USB_DRIVER_NAME, prompt ? prompt : "memory", l);
	print_hex_dump(KERN_INFO, PCAN_USB_DRIVER_NAME " ", DUMP_PREFIX_NONE,
		       DUMP_WIDTH, 1, p, l, false);
}

/*
 * initialize a time_ref object with usb adapter own settings
 */
void peak_usb_init_time_ref(struct peak_time_ref *time_ref,
			    const struct peak_usb_adapter *adapter)
{
	if (time_ref) {
		memset(time_ref, 0, sizeof(struct peak_time_ref));
		time_ref->adapter = adapter;
	}
}

/*
 * sometimes, another now may be  more recent than current one...
 */
void peak_usb_update_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
{
	time_ref->ts_dev_2 = ts_now;

	/* should wait at least two passes before computing */
	if (ktime_to_ns(time_ref->tv_host) > 0) {
		u32 delta_ts = time_ref->ts_dev_2 - time_ref->ts_dev_1;

		if (time_ref->ts_dev_2 < time_ref->ts_dev_1)
			delta_ts &= (1 << time_ref->adapter->ts_used_bits) - 1;

		time_ref->ts_total += delta_ts;
	}
}

/*
 * register device timestamp as now
 */
void peak_usb_set_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
{
	if (ktime_to_ns(time_ref->tv_host_0) == 0) {
		/* use monotonic clock to correctly compute further deltas */
		time_ref->tv_host_0 = ktime_get();
		time_ref->tv_host = ktime_set(0, 0);
	} else {
		/*
		 * delta_us should not be >= 2^32 => delta should be < 4294s
		 * handle 32-bits wrapping here: if count of s. reaches 4200,
		 * reset counters and change time base
		 */
		if (ktime_to_ns(time_ref->tv_host)) {
			ktime_t delta = ktime_sub(time_ref->tv_host,
						  time_ref->tv_host_0);
			if (ktime_to_ns(delta) > (4200ull * NSEC_PER_SEC)) {
				time_ref->tv_host_0 = time_ref->tv_host;
				time_ref->ts_total = 0;
			}
		}

		time_ref