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authorEvgeny Boger <boger@contactless.ru>2014-01-24 03:56:18 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-24 04:37:04 +0400
commit3089a4c8d3abc7e2ab105d1d39d415110d1566d6 (patch)
tree5064f69853949cb8b5d245c932f65a3202d21219 /drivers/w1/w1_int.c
parent63509beaf7ed7a9dc8c574be61189fce791489f0 (diff)
downloadlinux-3089a4c8d3abc7e2ab105d1d39d415110d1566d6.tar.xz
drivers/w1/masters/w1-gpio.c: add strong pullup emulation
Strong pullup is emulated by driving pin logic high after write command when using tri-state push-pull GPIO. Signed-off-by: Evgeny Boger <boger@contactless.ru> Cc: Greg KH <greg@kroah.com> Acked-by: David Fries <david@fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/w1/w1_int.c')
-rw-r--r--drivers/w1/w1_int.c12
1 files changed, 0 insertions, 12 deletions
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index 5a98649f6abc..590bd8a7cd1b 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -117,18 +117,6 @@ int w1_add_master_device(struct w1_bus_master *master)
printk(KERN_ERR "w1_add_master_device: invalid function set\n");
return(-EINVAL);
}
- /* While it would be electrically possible to make a device that
- * generated a strong pullup in bit bang mode, only hardware that
- * controls 1-wire time frames are even expected to support a strong
- * pullup. w1_io.c would need to support calling set_pullup before
- * the last write_bit operation of a w1_write_8 which it currently
- * doesn't.
- */
- if (!master->write_byte && !master->touch_bit && master->set_pullup) {
- printk(KERN_ERR "w1_add_master_device: set_pullup requires "
- "write_byte or touch_bit, disabling\n");
- master->set_pullup = NULL;
- }
/* Lock until the device is added (or not) to w1_masters. */
mutex_lock(&w1_mlock);