diff options
Diffstat (limited to 'drivers/w1')
| -rw-r--r-- | drivers/w1/masters/ds2490.c | 64 |
1 files changed, 45 insertions, 19 deletions
diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c index 4faf4f9ec06..59ad6e95af8 100644 --- a/drivers/w1/masters/ds2490.c +++ b/drivers/w1/masters/ds2490.c @@ -141,6 +141,10 @@ struct ds_device * 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; }; @@ -311,6 +315,25 @@ static void ds_dump_status(struct ds_device *dev, unsigned char *buf, int 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)) + 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; @@ -444,7 +467,7 @@ static int ds_wait_status(struct ds_device *dev, struct ds_status *st) if (err >= 16 && st->status & ST_EPOF) { printk(KERN_INFO "Resetting device after ST_EPOF.\n"); - ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0); + ds_reset_device(dev); /* Always dump the device status. */ count = 101; } @@ -509,24 +532,26 @@ static int ds_set_speed(struct ds_device *dev, int speed) 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; } @@ -577,11 +602,11 @@ 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); @@ -648,11 +673,11 @@ static int ds_write_block(struct ds_device *dev, u8 *buf, int len) if (err < 0) return err; - 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); @@ -849,7 +874,7 @@ static int ds_w1_init(struct ds_device *dev) * the input buffer. This will cause the next read to fail * see the note in ds_recv_data. */ - ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0); + ds_reset_device(dev); dev->master.data = dev; dev->master.touch_bit = &ds9490r_touch_bit; @@ -892,6 +917,7 @@ static int ds_probe(struct usb_interface *intf, return -ENOMEM; } dev->spu_sleep = 0; + dev->spu_bit = 0; dev->udev = usb_get_dev(udev); if (!dev->udev) { err = -ENOMEM; |