path: root/drivers/net/ieee802154/atusb.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * atusb.c - Driver for the ATUSB IEEE 802.15.4 dongle
 *
 * Written 2013 by Werner Almesberger <werner@almesberger.net>
 *
 * Copyright (c) 2015 - 2016 Stefan Schmidt <stefan@datenfreihafen.org>
 *
 * Based on at86rf230.c and spi_atusb.c.
 * at86rf230.c is
 * Copyright (C) 2009 Siemens AG
 * Written by: Dmitry Eremin-Solenikov <dmitry.baryshkov@siemens.com>
 *
 * spi_atusb.c is
 * Copyright (c) 2011 Richard Sharpe <realrichardsharpe@gmail.com>
 * Copyright (c) 2011 Stefan Schmidt <stefan@datenfreihafen.org>
 * Copyright (c) 2011 Werner Almesberger <werner@almesberger.net>
 *
 * USB initialization is
 * Copyright (c) 2013 Alexander Aring <alex.aring@gmail.com>
 *
 * Busware HUL support is
 * Copyright (c) 2017 Josef Filzmaier <j.filzmaier@gmx.at>
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/usb.h>
#include <linux/skbuff.h>

#include <net/cfg802154.h>
#include <net/mac802154.h>

#include "at86rf230.h"
#include "atusb.h"

#define ATUSB_JEDEC_ATMEL	0x1f	/* JEDEC manufacturer ID */

#define ATUSB_NUM_RX_URBS	4	/* allow for a bit of local latency */
#define ATUSB_ALLOC_DELAY_MS	100	/* delay after failed allocation */
#define ATUSB_TX_TIMEOUT_MS	200	/* on the air timeout */

struct atusb {
	struct ieee802154_hw *hw;
	struct usb_device *usb_dev;
	struct atusb_chip_data *data;
	int shutdown;			/* non-zero if shutting down */
	int err;			/* set by first error */

	/* RX variables */
	struct delayed_work work;	/* memory allocations */
	struct usb_anchor idle_urbs;	/* URBs waiting to be submitted */
	struct usb_anchor rx_urbs;	/* URBs waiting for reception */

	/* TX variables */
	struct usb_ctrlrequest tx_dr;
	struct urb *tx_urb;
	struct sk_buff *tx_skb;
	u8 tx_ack_seq;		/* current TX ACK sequence number */

	/* Firmware variable */
	unsigned char fw_ver_maj;	/* Firmware major version number */
	unsigned char fw_ver_min;	/* Firmware minor version number */
	unsigned char fw_hw_type;	/* Firmware hardware type */
};

struct atusb_chip_data {
	u16 t_channel_switch;
	int rssi_base_val;

	int (*set_channel)(struct ieee802154_hw*, u8, u8);
	int (*set_txpower)(struct ieee802154_hw*, s32);
};

static int atusb_write_subreg(struct atusb *atusb, u8 reg, u8 mask,
			      u8 shift, u8 value)
{
	struct usb_device *usb_dev = atusb->usb_dev;
	u8 orig, tmp;
	int ret = 0;

	dev_dbg(&usb_dev->dev, "%s: 0x%02x <- 0x%02x\n", __func__, reg, value);

	ret = usb_control_msg_recv(usb_dev, 0, ATUSB_REG_READ, ATUSB_REQ_FROM_DEV,
				   0, reg, &orig, 1, 1000, GFP_KERNEL);
	if (ret < 0)
		return ret;

	/* Write the value only into that part of the register which is allowed
	 * by the mask. All other bits stay as before.
	 */
	tmp = orig & ~mask;
	tmp |= (value << shift) & mask;

	if (tmp != orig)
		ret = usb_control_msg_send(usb_dev, 0, ATUSB_REG_WRITE, ATUSB_REQ_TO_DEV,
					   tmp, reg, NULL, 0, 1000, GFP_KERNEL);

	return ret;
}

static int atusb_read_subreg(struct atusb *lp,
			     unsigned int addr, unsigned int mask,
			     unsigned int shift)
{
	int reg, ret;

	ret = usb_control_msg_recv(lp->usb_dev, 0, ATUSB_REG_READ, ATUSB_REQ_FROM_DEV,
				   0, addr, &reg, 1, 1000, GFP_KERNEL);
	if (ret < 0)
		return ret;

	reg = (reg & mask) >> shift;

	return reg;
}

static int atusb_get_and_clear_error(struct atusb *atusb)
{
	int err = atusb->err;

	atusb->err = 0;
	return err;
}

/* ----- skb allocation ---------------------------------------------------- */

#define MAX_PSDU	127
#define MAX_RX_XFER	(1 + MAX_PSDU + 2 + 1)	/* PHR+PSDU+CRC+LQI */

#define SKB_ATUSB(skb)	(*(struct atusb **)(skb)->cb)

static void atusb_in(struct urb *urb);

static int atusb_submit_rx_urb(struct atusb *atusb, struct urb *urb)
{
	struct usb_device *usb_dev = atusb->usb_dev;
	struct sk_buff *skb = urb->context;
	int ret;

	if (!skb) {
		skb = alloc_skb(MAX_RX_XFER, GFP_KERNEL);
		if (!skb) {
			dev_warn_ratelimited(&usb_dev->dev,
					     "atusb_in: can't allocate skb\n");
			return -ENOMEM;
		}
		skb_put(skb, MAX_RX_XFER);
		SKB_ATUSB(skb) = atusb;
	}

	usb_fill_bulk_urb(urb, usb_dev, usb_rcvbulkpipe(usb_dev, 1),
			  skb->data, MAX_RX_XFER, atusb_in, skb);
	usb_anchor_urb(urb, &atusb->rx_urbs);

	ret = usb_submit_urb(urb, GFP_KERNEL);
	if (ret) {
		usb_unanchor_urb(urb);
		kfree_skb(skb);
		urb->context = NULL;
	}
	return ret;
}