#define COMM_DT 0x2000
#define COMM_SPU 0x1000
#define COMM_F 0x0800
-#define COMM_NTP 0x0400
+#define COMM_NTF 0x0400
#define COMM_ICP 0x0200
#define COMM_RST 0x0100
#define ST_IDLE 0x20 /* DS2490 is currently idle */
#define ST_EPOF 0x80
+/* 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
* 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;
};
static int ds_probe(struct usb_interface *, const struct usb_device_id *);
static void ds_disconnect(struct usb_interface *);
-static inline void ds_dump_status(unsigned char *, unsigned char *, int);
static int ds_send_control(struct ds_device *, u16, u16);
static int ds_send_control_cmd(struct ds_device *, u16, u16);
return err;
}
-static inline void ds_dump_status(unsigned char *buf, unsigned char *str, int off)
-{
- printk("%45s: %8x\n", str, buf[off]);
-}
-
static int ds_recv_status_nodump(struct ds_device *dev, struct ds_status *st,
unsigned char *buf, int size)
{
return count;
}
-static int ds_recv_status(struct ds_device *dev, struct ds_status *st)
+static inline void ds_print_msg(unsigned char *buf, unsigned char *str, int off)
{
- unsigned char buf[64];
- int count, err = 0, i;
-
- memcpy(st, buf, sizeof(*st));
+ printk(KERN_INFO "%45s: %8x\n", str, buf[off]);
+}
- count = ds_recv_status_nodump(dev, st, buf, sizeof(buf));
- if (count < 0)
- return err;
+static void ds_dump_status(struct ds_device *dev, unsigned char *buf, int count)
+{
+ int i;
- printk("0x%x: count=%d, status: ", dev->ep[EP_STATUS], count);
+ printk(KERN_INFO "0x%x: count=%d, status: ", dev->ep[EP_STATUS], count);
for (i=0; i<count; ++i)
printk("%02x ", buf[i]);
- printk("\n");
+ printk(KERN_INFO "\n");
if (count >= 16) {
- ds_dump_status(buf, "enable flag", 0);
- ds_dump_status(buf, "1-wire speed", 1);
- ds_dump_status(buf, "strong pullup duration", 2);
- ds_dump_status(buf, "programming pulse duration", 3);
- ds_dump_status(buf, "pulldown slew rate control", 4);
- ds_dump_status(buf, "write-1 low time", 5);
- ds_dump_status(buf, "data sample offset/write-0 recovery time", 6);
- ds_dump_status(buf, "reserved (test register)", 7);
- ds_dump_status(buf, "device status flags", 8);
- ds_dump_status(buf, "communication command byte 1", 9);
- ds_dump_status(buf, "communication command byte 2", 10);
- ds_dump_status(buf, "communication command buffer status", 11);
- ds_dump_status(buf, "1-wire data output buffer status", 12);
- ds_dump_status(buf, "1-wire data input buffer status", 13);
- ds_dump_status(buf, "reserved", 14);
- ds_dump_status(buf, "reserved", 15);
+ 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);
}
-
- memcpy(st, buf, sizeof(*st));
-
- if (st->status & ST_EPOF) {
- printk(KERN_INFO "Resetting device after ST_EPOF.\n");
- err = ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
- if (err)
- return err;
- count = ds_recv_status_nodump(dev, st, buf, sizeof(buf));
- if (count < 0)
- return err;
+ 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)
+ printk(KERN_INFO "NRS: Reset no presence or ...\n");
+ if (buf[i] & RR_SH)
+ printk(KERN_INFO "SH: short on reset or set path\n");
+ if (buf[i] & RR_APP)
+ printk(KERN_INFO "APP: alarming presence on reset\n");
+ if (buf[i] & RR_VPP)
+ printk(KERN_INFO "VPP: 12V expected not seen\n");
+ if (buf[i] & RR_CMP)
+ printk(KERN_INFO "CMP: compare error\n");
+ if (buf[i] & RR_CRC)
+ printk(KERN_INFO "CRC: CRC error detected\n");
+ if (buf[i] & RR_RDP)
+ printk(KERN_INFO "RDP: redirected page\n");
+ if (buf[i] & RR_EOS)
+ printk(KERN_INFO "EOS: end of search error\n");
}
+}
- return err;
+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))
+ printk(KERN_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))
+ printk(KERN_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[0x20];
+ int count;
+
printk(KERN_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, &st);
+
+ count = ds_recv_status_nodump(dev, &st, buf, sizeof(buf));
+ ds_dump_status(dev, buf, count);
return err;
}
if (err)
return err;
- err = ds_recv_status(dev, st);
+ err = ds_dump_status(dev, st);
return err;
}
printk("\n");
}
#endif
- } while(!(buf[0x08] & 0x20) && !(err < 0) && ++count < 100);
+ } while (!(buf[0x08] & ST_IDLE) && !(err < 0) && ++count < 100);
+ if (err >= 16 && st->status & ST_EPOF) {
+ printk(KERN_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);
- if (((err > 16) && (buf[0x10] & 0x01)) || count >= 100 || err < 0) {
- ds_recv_status(dev, st);
+ /* 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
+ else
return 0;
}
-static int ds_reset(struct ds_device *dev, struct ds_status *st)
+static int ds_reset(struct ds_device *dev)
{
int err;
- //err = ds_send_control(dev, COMM_1_WIRE_RESET | COMM_F | COMM_IM | COMM_SE, SPEED_FLEXIBLE);
- err = ds_send_control(dev, 0x43, SPEED_NORMAL);
+ /* 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;
- ds_wait_status(dev, st);
-#if 0
- if (st->command_buffer_status) {
- printk(KERN_INFO "Short circuit.\n");
- return -EIO;
- }
-#endif
-
return 0;
}
static int ds_set_pullup(struct ds_device *dev, int delay)
{
- int err;
+ 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;
- dev->spu_sleep = 0;
- err = ds_send_control_mode(dev, MOD_PULSE_EN, delay ? PULSE_SPUE : 0);
+ err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
if (err)
return err;
- if (delay) {
- err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
- if (err)
- return err;
-
- /* Just storing delay would not get the trunication and
- * roundup.
- */
- dev->spu_sleep = del<<4;
- }
+ dev->spu_sleep = ms;
return err;
}
static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit)
{
- int err, count;
+ int err;
struct ds_status st;
- u16 value = (COMM_BIT_IO | COMM_IM) | ((bit) ? COMM_D : 0);
- u16 cmd;
- err = ds_send_control(dev, value, 0);
+ err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit ? COMM_D : 0),
+ 0);
if (err)
return err;
- count = 0;
- do {
- err = ds_wait_status(dev, &st);
- if (err)
- return err;
-
- cmd = st.command0 | (st.command1 << 8);
- } while (cmd != value && ++count < 10);
-
- if (err < 0 || count >= 10) {
- printk(KERN_ERR "Failed to obtain status.\n");
- return -EINVAL;
- }
+ ds_wait_status(dev, &st);
err = ds_recv_data(dev, tbit, sizeof(*tbit));
if (err < 0)
return 0;
}
+#if 0
static int ds_write_bit(struct ds_device *dev, u8 bit)
{
int err;
return 0;
}
+#endif
static int ds_write_byte(struct ds_device *dev, u8 byte)
{
struct ds_status st;
u8 rbyte;
- err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM | COMM_SPU, byte);
+ err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM | dev->spu_bit, byte);
if (err)
return err;
- if (dev->spu_sleep)
+ if (dev->spu_bit)
msleep(dev->spu_sleep);
err = ds_wait_status(dev, &st);
if (err < 0)
return err;
- ds_wait_status(dev, &st);
-
- err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | COMM_SPU, len);
+ err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | dev->spu_bit, len);
if (err)
return err;
- if (dev->spu_sleep)
+ if (dev->spu_bit)
msleep(dev->spu_sleep);
ds_wait_status(dev, &st);
return ret;
}
+#if 0
static void ds9490r_write_bit(void *data, u8 bit)
{
struct ds_device *dev = data;
ds_write_bit(dev, bit);
}
-static void ds9490r_write_byte(void *data, u8 byte)
-{
- struct ds_device *dev = data;
-
- ds_write_byte(dev, byte);
-}
-
static u8 ds9490r_read_bit(void *data)
{
struct ds_device *dev = data;
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)
{
static u8 ds9490r_reset(void *data)
{
struct ds_device *dev = data;
- struct ds_status st;
int err;
- memset(&st, 0, sizeof(st));
-
- err = ds_reset(dev, &st);
+ err = ds_reset(dev);
if (err)
return 1;
{
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;
return -ENOMEM;
}
dev->spu_sleep = 0;
+ dev->spu_bit = 0;
dev->udev = usb_get_dev(udev);
if (!dev->udev) {
err = -ENOMEM;