Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / w1 / masters / ds2490.c
diff --git a/kernel/drivers/w1/masters/ds2490.c b/kernel/drivers/w1/masters/ds2490.c
new file mode 100644 (file)
index 0000000..049a884
--- /dev/null
@@ -0,0 +1,1090 @@
+/*
+ *     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 "../w1_int.h"
+#include "../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;
+
+       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 struct usb_device_id ds_id_table [] = {
+       { USB_DEVICE(0x04fa, 0x2490) },
+       { },
+};
+MODULE_DEVICE_TABLE(usb, ds_id_table);
+
+static int ds_probe(struct usb_interface *, const struct usb_device_id *);
+static void ds_disconnect(struct usb_interface *);
+
+static int ds_send_control(struct ds_device *, u16, u16);
+static int ds_send_control_cmd(struct ds_device *, u16, u16);
+
+static LIST_HEAD(ds_devices);
+static DEFINE_MUTEX(ds_mutex);
+
+static struct usb_driver ds_driver = {
+       .name =         "DS9490R",
+       .probe =        ds_probe,
+       .disconnect =   ds_disconnect,
+       .id_table =     ds_id_table,
+};
+
+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 int ds_recv_status_nodump(struct ds_device *dev, struct ds_status *st,
+                                unsigned char *buf, int size)
+{
+       int count, err;
+
+       memset(st, 0, sizeof(*st));
+
+       count = 0;
+       err = usb_interrupt_msg(dev->udev, usb_rcvintpipe(dev->udev,
+               dev->ep[EP_STATUS]), buf, size, &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 (count >= sizeof(*st))
+               memcpy(st, buf, sizeof(*st));
+
+       return count;
+}
+
+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 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;
+       struct ds_status st;
+
+       /* 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) {
+               u8 buf[ST_SIZE];
+               int count;
+
+               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]));
+
+               count = ds_recv_status_nodump(dev, &st, buf, sizeof(buf));
+               ds_dump_status(dev, buf, count);
+               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;
+       u8 buf[ST_SIZE];
+
+       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_nodump(dev, &st, buf, sizeof(buf));
+               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)
+{
+       u8 buf[ST_SIZE];
+       int err, count = 0;
+
+       do {
+               st->status = 0;
+               err = ds_recv_status_nodump(dev, st, buf, sizeof(buf));
+#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 ", 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, 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;
+       u8 rbyte;
+
+       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, &rbyte, sizeof(rbyte));
+       if (err < 0)
+               return err;
+
+       return !(byte == rbyte);
+}
+
+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;
+       u8 st_buf[ST_SIZE];
+       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.
+        */
+       u64 buf[2*64/8];
+
+       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);
+
+               if (ds_recv_status_nodump(dev, &st, st_buf, sizeof(st_buf)) <
+                       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, sizeof(buf));
+                       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);
+}
+
+#if 0
+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)
+{
+       u8 ret;
+       struct ds_device *dev = data;
+
+       if (ds_touch_bit(dev, bit, &ret))
+               return 0;
+
+       return ret;
+}
+
+#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;
+       u8 bit = 0;
+
+       err = ds_touch_bit(dev, 1, &bit);
+       if (err)
+               return 0;
+
+       return bit & 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;
+       u8 byte = 0;
+
+       err = ds_read_byte(dev, &byte);
+       if (err)
+               return 0;
+
+       return byte;
+}
+
+static void ds9490r_write_block(void *data, const u8 *buf, int len)
+{
+       struct ds_device *dev = data;
+
+       ds_write_block(dev, (u8 *)buf, len);
+}
+
+static u8 ds9490r_read_block(void *data, u8 *buf, int len)
+{
+       struct ds_device *dev = data;
+       int err;
+
+       err = ds_read_block(dev, buf, len);
+       if (err < 0)
+               return 0;
+
+       return len;
+}
+
+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);
+}
+
+module_usb_driver(ds_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
+MODULE_DESCRIPTION("DS2490 USB <-> W1 bus master driver (DS9490*)");