v4.19.13 snapshot.
diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c
new file mode 100644
index 0000000..0f4ecfc
--- /dev/null
+++ b/drivers/w1/masters/ds2490.c
@@ -0,0 +1,1105 @@
+/*
+ * ds2490.c USB to one wire bridge
+ *
+ * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#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->altsetting[alt].desc.bInterfaceNumber, alt);
+ if (err) {
+ dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
+ "for %d interface: err=%d.\n", alt,
+ intf->altsetting[alt].desc.bInterfaceNumber, err);
+ goto err_out_clear;
+ }
+
+ iface_desc = &intf->altsetting[alt];
+ 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");