Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1091 insertions, 0 deletions

diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c
new file mode 100644
index 000000000..e17c8f70d
--- /dev/null
+++ b/drivers/w1/masters/ds2490.c
@@ -0,0 +1,1091 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	ds2490.c  USB to one wire bridge
+ *
+ * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/usb.h>
+#include <linux/slab.h>
+
+#include <linux/w1.h>
+
+/* USB Standard */
+/* USB Control request vendor type */
+#define VENDOR				0x40
+
+/* COMMAND TYPE CODES */
+#define CONTROL_CMD			0x00
+#define COMM_CMD			0x01
+#define MODE_CMD			0x02
+
+/* CONTROL COMMAND CODES */
+#define CTL_RESET_DEVICE		0x0000
+#define CTL_START_EXE			0x0001
+#define CTL_RESUME_EXE			0x0002
+#define CTL_HALT_EXE_IDLE		0x0003
+#define CTL_HALT_EXE_DONE		0x0004
+#define CTL_FLUSH_COMM_CMDS		0x0007
+#define CTL_FLUSH_RCV_BUFFER		0x0008
+#define CTL_FLUSH_XMT_BUFFER		0x0009
+#define CTL_GET_COMM_CMDS		0x000A
+
+/* MODE COMMAND CODES */
+#define MOD_PULSE_EN			0x0000
+#define MOD_SPEED_CHANGE_EN		0x0001
+#define MOD_1WIRE_SPEED			0x0002
+#define MOD_STRONG_PU_DURATION		0x0003
+#define MOD_PULLDOWN_SLEWRATE		0x0004
+#define MOD_PROG_PULSE_DURATION		0x0005
+#define MOD_WRITE1_LOWTIME		0x0006
+#define MOD_DSOW0_TREC			0x0007
+
+/* COMMUNICATION COMMAND CODES */
+#define COMM_ERROR_ESCAPE		0x0601
+#define COMM_SET_DURATION		0x0012
+#define COMM_BIT_IO			0x0020
+#define COMM_PULSE			0x0030
+#define COMM_1_WIRE_RESET		0x0042
+#define COMM_BYTE_IO			0x0052
+#define COMM_MATCH_ACCESS		0x0064
+#define COMM_BLOCK_IO			0x0074
+#define COMM_READ_STRAIGHT		0x0080
+#define COMM_DO_RELEASE			0x6092
+#define COMM_SET_PATH			0x00A2
+#define COMM_WRITE_SRAM_PAGE		0x00B2
+#define COMM_WRITE_EPROM		0x00C4
+#define COMM_READ_CRC_PROT_PAGE		0x00D4
+#define COMM_READ_REDIRECT_PAGE_CRC	0x21E4
+#define COMM_SEARCH_ACCESS		0x00F4
+
+/* Communication command bits */
+#define COMM_TYPE			0x0008
+#define COMM_SE				0x0008
+#define COMM_D				0x0008
+#define COMM_Z				0x0008
+#define COMM_CH				0x0008
+#define COMM_SM				0x0008
+#define COMM_R				0x0008
+#define COMM_IM				0x0001
+
+#define COMM_PS				0x4000
+#define COMM_PST			0x4000
+#define COMM_CIB			0x4000
+#define COMM_RTS			0x4000
+#define COMM_DT				0x2000
+#define COMM_SPU			0x1000
+#define COMM_F				0x0800
+#define COMM_NTF			0x0400
+#define COMM_ICP			0x0200
+#define COMM_RST			0x0100
+
+#define PULSE_PROG			0x01
+#define PULSE_SPUE			0x02
+
+#define BRANCH_MAIN			0xCC
+#define BRANCH_AUX			0x33
+
+/* Status flags */
+#define ST_SPUA				0x01  /* Strong Pull-up is active */
+#define ST_PRGA				0x02  /* 12V programming pulse is being generated */
+#define ST_12VP				0x04  /* external 12V programming voltage is present */
+#define ST_PMOD				0x08  /* DS2490 powered from USB and external sources */
+#define ST_HALT				0x10  /* DS2490 is currently halted */
+#define ST_IDLE				0x20  /* DS2490 is currently idle */
+#define ST_EPOF				0x80
+/* Status transfer size, 16 bytes status, 16 byte result flags */
+#define ST_SIZE				0x20
+
+/* Result Register flags */
+#define RR_DETECT			0xA5 /* New device detected */
+#define RR_NRS				0x01 /* Reset no presence or ... */
+#define RR_SH				0x02 /* short on reset or set path */
+#define RR_APP				0x04 /* alarming presence on reset */
+#define RR_VPP				0x08 /* 12V expected not seen */
+#define RR_CMP				0x10 /* compare error */
+#define RR_CRC				0x20 /* CRC error detected */
+#define RR_RDP				0x40 /* redirected page */
+#define RR_EOS				0x80 /* end of search error */
+
+#define SPEED_NORMAL			0x00
+#define SPEED_FLEXIBLE			0x01
+#define SPEED_OVERDRIVE			0x02
+
+#define NUM_EP				4
+#define EP_CONTROL			0
+#define EP_STATUS			1
+#define EP_DATA_OUT			2
+#define EP_DATA_IN			3
+
+struct ds_device {
+	struct list_head	ds_entry;
+
+	struct usb_device	*udev;
+	struct usb_interface	*intf;
+
+	int			ep[NUM_EP];
+
+	/* Strong PullUp
+	 * 0: pullup not active, else duration in milliseconds
+	 */
+	int			spu_sleep;
+	/* spu_bit contains COMM_SPU or 0 depending on if the strong pullup
+	 * should be active or not for writes.
+	 */
+	u16			spu_bit;
+
+	u8			st_buf[ST_SIZE];
+	u8			byte_buf;
+
+	struct w1_bus_master	master;
+};
+
+struct ds_status {
+	u8			enable;
+	u8			speed;
+	u8			pullup_dur;
+	u8			ppuls_dur;
+	u8			pulldown_slew;
+	u8			write1_time;
+	u8			write0_time;
+	u8			reserved0;
+	u8			status;
+	u8			command0;
+	u8			command1;
+	u8			command_buffer_status;
+	u8			data_out_buffer_status;
+	u8			data_in_buffer_status;
+	u8			reserved1;
+	u8			reserved2;
+};
+
+static LIST_HEAD(ds_devices);
+static DEFINE_MUTEX(ds_mutex);
+
+static int ds_send_control_cmd(struct ds_device *dev, u16 value, u16 index)
+{
+	int err;
+
+	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
+			CONTROL_CMD, VENDOR, value, index, NULL, 0, 1000);
+	if (err < 0) {
+		pr_err("Failed to send command control message %x.%x: err=%d.\n",
+				value, index, err);
+		return err;
+	}
+
+	return err;
+}
+
+static int ds_send_control_mode(struct ds_device *dev, u16 value, u16 index)
+{
+	int err;
+
+	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
+			MODE_CMD, VENDOR, value, index, NULL, 0, 1000);
+	if (err < 0) {
+		pr_err("Failed to send mode control message %x.%x: err=%d.\n",
+				value, index, err);
+		return err;
+	}
+
+	return err;
+}
+
+static int ds_send_control(struct ds_device *dev, u16 value, u16 index)
+{
+	int err;
+
+	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
+			COMM_CMD, VENDOR, value, index, NULL, 0, 1000);
+	if (err < 0) {
+		pr_err("Failed to send control message %x.%x: err=%d.\n",
+				value, index, err);
+		return err;
+	}
+
+	return err;
+}
+
+static inline void ds_print_msg(unsigned char *buf, unsigned char *str, int off)
+{
+	pr_info("%45s: %8x\n", str, buf[off]);
+}
+
+static void ds_dump_status(struct ds_device *dev, unsigned char *buf, int count)
+{
+	int i;
+
+	pr_info("0x%x: count=%d, status: ", dev->ep[EP_STATUS], count);
+	for (i = 0; i < count; ++i)
+		pr_info("%02x ", buf[i]);
+	pr_info("\n");
+
+	if (count >= 16) {
+		ds_print_msg(buf, "enable flag", 0);
+		ds_print_msg(buf, "1-wire speed", 1);
+		ds_print_msg(buf, "strong pullup duration", 2);
+		ds_print_msg(buf, "programming pulse duration", 3);
+		ds_print_msg(buf, "pulldown slew rate control", 4);
+		ds_print_msg(buf, "write-1 low time", 5);
+		ds_print_msg(buf, "data sample offset/write-0 recovery time",
+			6);
+		ds_print_msg(buf, "reserved (test register)", 7);
+		ds_print_msg(buf, "device status flags", 8);
+		ds_print_msg(buf, "communication command byte 1", 9);
+		ds_print_msg(buf, "communication command byte 2", 10);
+		ds_print_msg(buf, "communication command buffer status", 11);
+		ds_print_msg(buf, "1-wire data output buffer status", 12);
+		ds_print_msg(buf, "1-wire data input buffer status", 13);
+		ds_print_msg(buf, "reserved", 14);
+		ds_print_msg(buf, "reserved", 15);
+	}
+	for (i = 16; i < count; ++i) {
+		if (buf[i] == RR_DETECT) {
+			ds_print_msg(buf, "new device detect", i);
+			continue;
+		}
+		ds_print_msg(buf, "Result Register Value: ", i);
+		if (buf[i] & RR_NRS)
+			pr_info("NRS: Reset no presence or ...\n");
+		if (buf[i] & RR_SH)
+			pr_info("SH: short on reset or set path\n");
+		if (buf[i] & RR_APP)
+			pr_info("APP: alarming presence on reset\n");
+		if (buf[i] & RR_VPP)
+			pr_info("VPP: 12V expected not seen\n");
+		if (buf[i] & RR_CMP)
+			pr_info("CMP: compare error\n");
+		if (buf[i] & RR_CRC)
+			pr_info("CRC: CRC error detected\n");
+		if (buf[i] & RR_RDP)
+			pr_info("RDP: redirected page\n");
+		if (buf[i] & RR_EOS)
+			pr_info("EOS: end of search error\n");
+	}
+}
+
+static int ds_recv_status(struct ds_device *dev, struct ds_status *st,
+			  bool dump)
+{
+	int count, err;
+
+	if (st)
+		memset(st, 0, sizeof(*st));
+
+	count = 0;
+	err = usb_interrupt_msg(dev->udev,
+				usb_rcvintpipe(dev->udev,
+					       dev->ep[EP_STATUS]),
+				dev->st_buf, sizeof(dev->st_buf),
+				&count, 1000);
+	if (err < 0) {
+		pr_err("Failed to read 1-wire data from 0x%x: err=%d.\n",
+		       dev->ep[EP_STATUS], err);
+		return err;
+	}
+
+	if (dump)
+		ds_dump_status(dev, dev->st_buf, count);
+
+	if (st && count >= sizeof(*st))
+		memcpy(st, dev->st_buf, sizeof(*st));
+
+	return count;
+}
+
+static void ds_reset_device(struct ds_device *dev)
+{
+	ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
+	/* Always allow strong pullup which allow individual writes to use
+	 * the strong pullup.
+	 */
+	if (ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_SPUE))
+		pr_err("ds_reset_device: Error allowing strong pullup\n");
+	/* Chip strong pullup time was cleared. */
+	if (dev->spu_sleep) {
+		/* lower 4 bits are 0, see ds_set_pullup */
+		u8 del = dev->spu_sleep>>4;
+		if (ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del))
+			pr_err("ds_reset_device: Error setting duration\n");
+	}
+}
+
+static int ds_recv_data(struct ds_device *dev, unsigned char *buf, int size)
+{
+	int count, err;
+
+	/* Careful on size.  If size is less than what is available in
+	 * the input buffer, the device fails the bulk transfer and
+	 * clears the input buffer.  It could read the maximum size of
+	 * the data buffer, but then do you return the first, last, or
+	 * some set of the middle size bytes?  As long as the rest of
+	 * the code is correct there will be size bytes waiting.  A
+	 * call to ds_wait_status will wait until the device is idle
+	 * and any data to be received would have been available.
+	 */
+	count = 0;
+	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]),
+				buf, size, &count, 1000);
+	if (err < 0) {
+		pr_info("Clearing ep0x%x.\n", dev->ep[EP_DATA_IN]);
+		usb_clear_halt(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]));
+		ds_recv_status(dev, NULL, true);
+		return err;
+	}
+
+#if 0
+	{
+		int i;
+
+		printk("%s: count=%d: ", __func__, count);
+		for (i = 0; i < count; ++i)
+			printk("%02x ", buf[i]);
+		printk("\n");
+	}
+#endif
+	return count;
+}
+
+static int ds_send_data(struct ds_device *dev, unsigned char *buf, int len)
+{
+	int count, err;
+
+	count = 0;
+	err = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->ep[EP_DATA_OUT]), buf, len, &count, 1000);
+	if (err < 0) {
+		pr_err("Failed to write 1-wire data to ep0x%x: "
+			"err=%d.\n", dev->ep[EP_DATA_OUT], err);
+		return err;
+	}
+
+	return err;
+}
+
+#if 0
+
+int ds_stop_pulse(struct ds_device *dev, int limit)
+{
+	struct ds_status st;
+	int count = 0, err = 0;
+
+	do {
+		err = ds_send_control(dev, CTL_HALT_EXE_IDLE, 0);
+		if (err)
+			break;
+		err = ds_send_control(dev, CTL_RESUME_EXE, 0);
+		if (err)
+			break;
+		err = ds_recv_status(dev, &st, false);
+		if (err)
+			break;
+
+		if ((st.status & ST_SPUA) == 0) {
+			err = ds_send_control_mode(dev, MOD_PULSE_EN, 0);
+			if (err)
+				break;
+		}
+	} while (++count < limit);
+
+	return err;
+}
+
+int ds_detect(struct ds_device *dev, struct ds_status *st)
+{
+	int err;
+
+	err = ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
+	if (err)
+		return err;
+
+	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, 0);
+	if (err)
+		return err;
+
+	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM | COMM_TYPE, 0x40);
+	if (err)
+		return err;
+
+	err = ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_PROG);
+	if (err)
+		return err;
+
+	err = ds_dump_status(dev, st);
+
+	return err;
+}
+
+#endif  /*  0  */
+
+static int ds_wait_status(struct ds_device *dev, struct ds_status *st)
+{
+	int err, count = 0;
+
+	do {
+		st->status = 0;
+		err = ds_recv_status(dev, st, false);
+#if 0
+		if (err >= 0) {
+			int i;
+			printk("0x%x: count=%d, status: ", dev->ep[EP_STATUS], err);
+			for (i = 0; i < err; ++i)
+				printk("%02x ", dev->st_buf[i]);
+			printk("\n");
+		}
+#endif
+	} while (!(st->status & ST_IDLE) && !(err < 0) && ++count < 100);
+
+	if (err >= 16 && st->status & ST_EPOF) {
+		pr_info("Resetting device after ST_EPOF.\n");
+		ds_reset_device(dev);
+		/* Always dump the device status. */
+		count = 101;
+	}
+
+	/* Dump the status for errors or if there is extended return data.
+	 * The extended status includes new device detection (maybe someone
+	 * can do something with it).
+	 */
+	if (err > 16 || count >= 100 || err < 0)
+		ds_dump_status(dev, dev->st_buf, err);
+
+	/* Extended data isn't an error.  Well, a short is, but the dump
+	 * would have already told the user that and we can't do anything
+	 * about it in software anyway.
+	 */
+	if (count >= 100 || err < 0)
+		return -1;
+	else
+		return 0;
+}
+
+static int ds_reset(struct ds_device *dev)
+{
+	int err;
+
+	/* Other potentionally interesting flags for reset.
+	 *
+	 * COMM_NTF: Return result register feedback.  This could be used to
+	 * detect some conditions such as short, alarming presence, or
+	 * detect if a new device was detected.
+	 *
+	 * COMM_SE which allows SPEED_NORMAL, SPEED_FLEXIBLE, SPEED_OVERDRIVE:
+	 * Select the data transfer rate.
+	 */
+	err = ds_send_control(dev, COMM_1_WIRE_RESET | COMM_IM, SPEED_NORMAL);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+#if 0
+static int ds_set_speed(struct ds_device *dev, int speed)
+{
+	int err;
+
+	if (speed != SPEED_NORMAL && speed != SPEED_FLEXIBLE && speed != SPEED_OVERDRIVE)
+		return -EINVAL;
+
+	if (speed != SPEED_OVERDRIVE)
+		speed = SPEED_FLEXIBLE;
+
+	speed &= 0xff;
+
+	err = ds_send_control_mode(dev, MOD_1WIRE_SPEED, speed);
+	if (err)
+		return err;
+
+	return err;
+}
+#endif  /*  0  */
+
+static int ds_set_pullup(struct ds_device *dev, int delay)
+{
+	int err = 0;
+	u8 del = 1 + (u8)(delay >> 4);
+	/* Just storing delay would not get the trunication and roundup. */
+	int ms = del<<4;
+
+	/* Enable spu_bit if a delay is set. */
+	dev->spu_bit = delay ? COMM_SPU : 0;
+	/* If delay is zero, it has already been disabled, if the time is
+	 * the same as the hardware was last programmed to, there is also
+	 * nothing more to do.  Compare with the recalculated value ms
+	 * rather than del or delay which can have a different value.
+	 */
+	if (delay == 0 || ms == dev->spu_sleep)
+		return err;
+
+	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
+	if (err)
+		return err;
+
+	dev->spu_sleep = ms;
+
+	return err;
+}
+
+static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit)
+{
+	int err;
+	struct ds_status st;
+
+	err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit ? COMM_D : 0),
+		0);
+	if (err)
+		return err;
+
+	ds_wait_status(dev, &st);
+
+	err = ds_recv_data(dev, tbit, sizeof(*tbit));
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+#if 0
+static int ds_write_bit(struct ds_device *dev, u8 bit)
+{
+	int err;
+	struct ds_status st;
+
+	/* Set COMM_ICP to write without a readback.  Note, this will
+	 * produce one time slot, a down followed by an up with COMM_D
+	 * only determing the timing.
+	 */
+	err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | COMM_ICP |
+		(bit ? COMM_D : 0), 0);
+	if (err)
+		return err;
+
+	ds_wait_status(dev, &st);
+
+	return 0;
+}
+#endif
+
+static int ds_write_byte(struct ds_device *dev, u8 byte)
+{
+	int err;
+	struct ds_status st;
+
+	err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM | dev->spu_bit, byte);
+	if (err)
+		return err;
+
+	if (dev->spu_bit)
+		msleep(dev->spu_sleep);
+
+	err = ds_wait_status(dev, &st);
+	if (err)
+		return err;
+
+	err = ds_recv_data(dev, &dev->byte_buf, 1);
+	if (err < 0)
+		return err;
+
+	return !(byte == dev->byte_buf);
+}
+
+static int ds_read_byte(struct ds_device *dev, u8 *byte)
+{
+	int err;
+	struct ds_status st;
+
+	err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM, 0xff);
+	if (err)
+		return err;
+
+	ds_wait_status(dev, &st);
+
+	err = ds_recv_data(dev, byte, sizeof(*byte));
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
+{
+	struct ds_status st;
+	int err;
+
+	if (len > 64*1024)
+		return -E2BIG;
+
+	memset(buf, 0xFF, len);
+
+	err = ds_send_data(dev, buf, len);
+	if (err < 0)
+		return err;
+
+	err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM, len);
+	if (err)
+		return err;
+
+	ds_wait_status(dev, &st);
+
+	memset(buf, 0x00, len);
+	err = ds_recv_data(dev, buf, len);
+
+	return err;
+}
+
+static int ds_write_block(struct ds_device *dev, u8 *buf, int len)
+{
+	int err;
+	struct ds_status st;
+
+	err = ds_send_data(dev, buf, len);
+	if (err < 0)
+		return err;
+
+	err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | dev->spu_bit, len);
+	if (err)
+		return err;
+
+	if (dev->spu_bit)
+		msleep(dev->spu_sleep);
+
+	ds_wait_status(dev, &st);
+
+	err = ds_recv_data(dev, buf, len);
+	if (err < 0)
+		return err;
+
+	return !(err == len);
+}
+
+static void ds9490r_search(void *data, struct w1_master *master,
+	u8 search_type, w1_slave_found_callback callback)
+{
+	/* When starting with an existing id, the first id returned will
+	 * be that device (if it is still on the bus most likely).
+	 *
+	 * If the number of devices found is less than or equal to the
+	 * search_limit, that number of IDs will be returned.  If there are
+	 * more, search_limit IDs will be returned followed by a non-zero
+	 * discrepency value.
+	 */
+	struct ds_device *dev = data;
+	int err;
+	u16 value, index;
+	struct ds_status st;
+	int search_limit;
+	int found = 0;
+	int i;
+
+	/* DS18b20 spec, 13.16 ms per device, 75 per second, sleep for
+	 * discovering 8 devices (1 bulk transfer and 1/2 FIFO size) at a time.
+	 */
+	const unsigned long jtime = msecs_to_jiffies(1000*8/75);
+	/* FIFO 128 bytes, bulk packet size 64, read a multiple of the
+	 * packet size.
+	 */
+	const size_t bufsize = 2 * 64;
+	u64 *buf;
+
+	buf = kmalloc(bufsize, GFP_KERNEL);
+	if (!buf)
+		return;
+
+	mutex_lock(&master->bus_mutex);
+
+	/* address to start searching at */
+	if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
+		goto search_out;
+	master->search_id = 0;
+
+	value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F |
+		COMM_RTS;
+	search_limit = master->max_slave_count;
+	if (search_limit > 255)
+		search_limit = 0;
+	index = search_type | (search_limit << 8);
+	if (ds_send_control(dev, value, index) < 0)
+		goto search_out;
+
+	do {
+		schedule_timeout(jtime);
+
+		err = ds_recv_status(dev, &st, false);
+		if (err < 0 || err < sizeof(st))
+			break;
+
+		if (st.data_in_buffer_status) {
+			/* Bulk in can receive partial ids, but when it does
+			 * they fail crc and will be discarded anyway.
+			 * That has only been seen when status in buffer
+			 * is 0 and bulk is read anyway, so don't read
+			 * bulk without first checking if status says there
+			 * is data to read.
+			 */
+			err = ds_recv_data(dev, (u8 *)buf, bufsize);
+			if (err < 0)
+				break;
+			for (i = 0; i < err/8; ++i) {
+				++found;
+				if (found <= search_limit)
+					callback(master, buf[i]);
+				/* can't know if there will be a discrepancy
+				 * value after until the next id */
+				if (found == search_limit)
+					master->search_id = buf[i];
+			}
+		}
+
+		if (test_bit(W1_ABORT_SEARCH, &master->flags))
+			break;
+	} while (!(st.status & (ST_IDLE | ST_HALT)));
+
+	/* only continue the search if some weren't found */
+	if (found <= search_limit) {
+		master->search_id = 0;
+	} else if (!test_bit(W1_WARN_MAX_COUNT, &master->flags)) {
+		/* Only max_slave_count will be scanned in a search,
+		 * but it will start where it left off next search
+		 * until all ids are identified and then it will start
+		 * over.  A continued search will report the previous
+		 * last id as the first id (provided it is still on the
+		 * bus).
+		 */
+		dev_info(&dev->udev->dev, "%s: max_slave_count %d reached, "
+			"will continue next search.\n", __func__,
+			master->max_slave_count);
+		set_bit(W1_WARN_MAX_COUNT, &master->flags);
+	}
+search_out:
+	mutex_unlock(&master->bus_mutex);
+	kfree(buf);
+}
+
+#if 0
+/*
+ * FIXME: if this disabled code is ever used in the future all ds_send_data()
+ * calls must be changed to use a DMAable buffer.
+ */
+static int ds_match_access(struct ds_device *dev, u64 init)
+{
+	int err;
+	struct ds_status st;
+
+	err = ds_send_data(dev, (unsigned char *)&init, sizeof(init));
+	if (err)
+		return err;
+
+	ds_wait_status(dev, &st);
+
+	err = ds_send_control(dev, COMM_MATCH_ACCESS | COMM_IM | COMM_RST, 0x0055);
+	if (err)
+		return err;
+
+	ds_wait_status(dev, &st);
+
+	return 0;
+}
+
+static int ds_set_path(struct ds_device *dev, u64 init)
+{
+	int err;
+	struct ds_status st;
+	u8 buf[9];
+
+	memcpy(buf, &init, 8);
+	buf[8] = BRANCH_MAIN;
+
+	err = ds_send_data(dev, buf, sizeof(buf));
+	if (err)
+		return err;
+
+	ds_wait_status(dev, &st);
+
+	err = ds_send_control(dev, COMM_SET_PATH | COMM_IM | COMM_RST, 0);
+	if (err)
+		return err;
+
+	ds_wait_status(dev, &st);
+
+	return 0;
+}
+
+#endif  /*  0  */
+
+static u8 ds9490r_touch_bit(void *data, u8 bit)
+{
+	struct ds_device *dev = data;
+
+	if (ds_touch_bit(dev, bit, &dev->byte_buf))
+		return 0;
+
+	return dev->byte_buf;
+}
+
+#if 0
+static void ds9490r_write_bit(void *data, u8 bit)
+{
+	struct ds_device *dev = data;
+
+	ds_write_bit(dev, bit);
+}
+
+static u8 ds9490r_read_bit(void *data)
+{
+	struct ds_device *dev = data;
+	int err;
+
+	err = ds_touch_bit(dev, 1, &dev->byte_buf);
+	if (err)
+		return 0;
+
+	return dev->byte_buf & 1;
+}
+#endif
+
+static void ds9490r_write_byte(void *data, u8 byte)
+{
+	struct ds_device *dev = data;
+
+	ds_write_byte(dev, byte);
+}
+
+static u8 ds9490r_read_byte(void *data)
+{
+	struct ds_device *dev = data;
+	int err;
+
+	err = ds_read_byte(dev, &dev->byte_buf);
+	if (err)
+		return 0;
+
+	return dev->byte_buf;
+}
+
+static void ds9490r_write_block(void *data, const u8 *buf, int len)
+{
+	struct ds_device *dev = data;
+	u8 *tbuf;
+
+	if (len <= 0)
+		return;
+
+	tbuf = kmemdup(buf, len, GFP_KERNEL);
+	if (!tbuf)
+		return;
+
+	ds_write_block(dev, tbuf, len);
+
+	kfree(tbuf);
+}
+
+static u8 ds9490r_read_block(void *data, u8 *buf, int len)
+{
+	struct ds_device *dev = data;
+	int err;
+	u8 *tbuf;
+
+	if (len <= 0)
+		return 0;
+
+	tbuf = kmalloc(len, GFP_KERNEL);
+	if (!tbuf)
+		return 0;
+
+	err = ds_read_block(dev, tbuf, len);
+	if (err >= 0)
+		memcpy(buf, tbuf, len);
+
+	kfree(tbuf);
+
+	return err >= 0 ? len : 0;
+}
+
+static u8 ds9490r_reset(void *data)
+{
+	struct ds_device *dev = data;
+	int err;
+
+	err = ds_reset(dev);
+	if (err)
+		return 1;
+
+	return 0;
+}
+
+static u8 ds9490r_set_pullup(void *data, int delay)
+{
+	struct ds_device *dev = data;
+
+	if (ds_set_pullup(dev, delay))
+		return 1;
+
+	return 0;
+}
+
+static int ds_w1_init(struct ds_device *dev)
+{
+	memset(&dev->master, 0, sizeof(struct w1_bus_master));
+
+	/* Reset the device as it can be in a bad state.
+	 * This is necessary because a block write will wait for data
+	 * to be placed in the output buffer and block any later
+	 * commands which will keep accumulating and the device will
+	 * not be idle.  Another case is removing the ds2490 module
+	 * while a bus search is in progress, somehow a few commands
+	 * get through, but the input transfers fail leaving data in
+	 * the input buffer.  This will cause the next read to fail
+	 * see the note in ds_recv_data.
+	 */
+	ds_reset_device(dev);
+
+	dev->master.data	= dev;
+	dev->master.touch_bit	= &ds9490r_touch_bit;
+	/* read_bit and write_bit in w1_bus_master are expected to set and
+	 * sample the line level.  For write_bit that means it is expected to
+	 * set it to that value and leave it there.  ds2490 only supports an
+	 * individual time slot at the lowest level.  The requirement from
+	 * pulling the bus state down to reading the state is 15us, something
+	 * that isn't realistic on the USB bus anyway.
+	dev->master.read_bit	= &ds9490r_read_bit;
+	dev->master.write_bit	= &ds9490r_write_bit;
+	*/
+	dev->master.read_byte	= &ds9490r_read_byte;
+	dev->master.write_byte	= &ds9490r_write_byte;
+	dev->master.read_block	= &ds9490r_read_block;
+	dev->master.write_block	= &ds9490r_write_block;
+	dev->master.reset_bus	= &ds9490r_reset;
+	dev->master.set_pullup	= &ds9490r_set_pullup;
+	dev->master.search	= &ds9490r_search;
+
+	return w1_add_master_device(&dev->master);
+}
+
+static void ds_w1_fini(struct ds_device *dev)
+{
+	w1_remove_master_device(&dev->master);
+}
+
+static int ds_probe(struct usb_interface *intf,
+		    const struct usb_device_id *udev_id)
+{
+	struct usb_device *udev = interface_to_usbdev(intf);
+	struct usb_endpoint_descriptor *endpoint;
+	struct usb_host_interface *iface_desc;
+	struct ds_device *dev;
+	int i, err, alt;
+
+	dev = kzalloc(sizeof(struct ds_device), GFP_KERNEL);
+	if (!dev) {
+		pr_info("Failed to allocate new DS9490R structure.\n");
+		return -ENOMEM;
+	}
+	dev->udev = usb_get_dev(udev);
+	if (!dev->udev) {
+		err = -ENOMEM;
+		goto err_out_free;
+	}
+	memset(dev->ep, 0, sizeof(dev->ep));
+
+	usb_set_intfdata(intf, dev);
+
+	err = usb_reset_configuration(dev->udev);
+	if (err) {
+		dev_err(&dev->udev->dev,
+			"Failed to reset configuration: err=%d.\n", err);
+		goto err_out_clear;
+	}
+
+	/* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
+	alt = 3;
+	err = usb_set_interface(dev->udev,
+		intf->cur_altsetting->desc.bInterfaceNumber, alt);
+	if (err) {
+		dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
+			"for %d interface: err=%d.\n", alt,
+			intf->cur_altsetting->desc.bInterfaceNumber, err);
+		goto err_out_clear;
+	}
+
+	iface_desc = intf->cur_altsetting;
+	if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
+		pr_info("Num endpoints=%d. It is not DS9490R.\n",
+			iface_desc->desc.bNumEndpoints);
+		err = -EINVAL;
+		goto err_out_clear;
+	}
+
+	/*
+	 * This loop doesn'd show control 0 endpoint,
+	 * so we will fill only 1-3 endpoints entry.
+	 */
+	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+		endpoint = &iface_desc->endpoint[i].desc;
+
+		dev->ep[i+1] = endpoint->bEndpointAddress;
+#if 0
+		printk("%d: addr=%x, size=%d, dir=%s, type=%x\n",
+			i, endpoint->bEndpointAddress, le16_to_cpu(endpoint->wMaxPacketSize),
+			(endpoint->bEndpointAddress & USB_DIR_IN)?"IN":"OUT",
+			endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
+#endif
+	}
+
+	err = ds_w1_init(dev);
+	if (err)
+		goto err_out_clear;
+
+	mutex_lock(&ds_mutex);
+	list_add_tail(&dev->ds_entry, &ds_devices);
+	mutex_unlock(&ds_mutex);
+
+	return 0;
+
+err_out_clear:
+	usb_set_intfdata(intf, NULL);
+	usb_put_dev(dev->udev);
+err_out_free:
+	kfree(dev);
+	return err;
+}
+
+static void ds_disconnect(struct usb_interface *intf)
+{
+	struct ds_device *dev;
+
+	dev = usb_get_intfdata(intf);
+	if (!dev)
+		return;
+
+	mutex_lock(&ds_mutex);
+	list_del(&dev->ds_entry);
+	mutex_unlock(&ds_mutex);
+
+	ds_w1_fini(dev);
+
+	usb_set_intfdata(intf, NULL);
+
+	usb_put_dev(dev->udev);
+	kfree(dev);
+}
+
+static const struct usb_device_id ds_id_table[] = {
+	{ USB_DEVICE(0x04fa, 0x2490) },
+	{ },
+};
+MODULE_DEVICE_TABLE(usb, ds_id_table);
+
+static struct usb_driver ds_driver = {
+	.name =		"DS9490R",
+	.probe =	ds_probe,
+	.disconnect =	ds_disconnect,
+	.id_table =	ds_id_table,
+};
+module_usb_driver(ds_driver);
+
+MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
+MODULE_DESCRIPTION("DS2490 USB <-> W1 bus master driver (DS9490*)");
+MODULE_LICENSE("GPL");