Eric Lee / linux-smarc-t335x-v3.2

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Commit f607e7fc5fb94d92030c4527287e9c149ddf9e65

Authored by Jean-François Dagenais
Committed by Linus Torvalds
1 parent 453a9bf347
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

w1: ds1wm: add a reset recovery parameter 

This fixes a regression in 3.0 reported by Paul Parsons regarding the
removal of the msleep(1) in the ds1wm_reset() function:

: The linux-3.0-rc4 DS1WM 1-wire driver is logging "bus error, retrying"
: error messages on an HP iPAQ hx4700 PDA (XScale-PXA270):
:
: <snip>
: Driver for 1-wire Dallas network protocol.
: DS1WM w1 busmaster driver - (c) 2004 Szabolcs Gyurko
: 1-Wire driver for the DS2760 battery monitor  chip  - (c) 2004-2005, Szabolcs Gyurko
: ds1wm ds1wm: pass: 1 bus error, retrying
: ds1wm ds1wm: pass: 2 bus error, retrying
: ds1wm ds1wm: pass: 3 bus error, retrying
: ds1wm ds1wm: pass: 4 bus error, retrying
: ds1wm ds1wm: pass: 5 bus error, retrying
: ...
:
: The visible result is that the battery charging LED is erratic; sometimes
: it works, mostly it doesn't.
:
: The linux-2.6.39 DS1WM 1-wire driver worked OK.  I haven't tried 3.0-rc1,
: 3.0-rc2, or 3.0-rc3.

This sleep should not be required on normal circuitry provided the
pull-ups on the bus are correctly adapted to the slaves.  Unfortunately,
this is not always the case.  The sleep is restored but as a parameter to
the probe function in the pdata.

[akpm@linux-foundation.org: coding-style fixes]
Reported-by: Paul Parsons <lost.distance@yahoo.com>
Tested-by: Paul Parsons <lost.distance@yahoo.com>
Signed-off-by: Jean-François Dagenais <dagenaisj@sonatest.com>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 4 changed files with 14 additions and 0 deletions Side-by-side Diff

... ... @@ -619,6 +619,7 @@
619 619 /* MFD cells (SPI, PWM, LED, DS1WM, MMC) */
620 620 static struct ds1wm_driver_data ds1wm_pdata = {
621 621 .active_high = 1,
  622 + .reset_recover_delay = 1,
622 623 };
623 624  
624 625 static struct resource ds1wm_resources[] = {
drivers/mfd/htc-pasic3.c
Diff comments   View file @ f607e7f
... ... @@ -99,6 +99,7 @@
99 99  
100 100 static struct ds1wm_driver_data ds1wm_pdata = {
101 101 .active_high = 0,
  102 + .reset_recover_delay = 1,
102 103 };
103 104  
104 105 static struct resource ds1wm_resources[] __initdata = {
drivers/w1/masters/ds1wm.c
Diff comments   View file @ f607e7f
... ... @@ -109,6 +109,7 @@
109 109 /* byte to write that makes all intr disabled, */
110 110 /* considering active_state (IAS) (optimization) */
111 111 u8 int_en_reg_none;
  112 + unsigned int reset_recover_delay; /* see ds1wm.h */
112 113 };
113 114  
114 115 static inline void ds1wm_write_register(struct ds1wm_data *ds1wm_data, u32 reg,
... ... @@ -187,6 +188,9 @@
187 188 return 1;
188 189 }
189 190  
  191 + if (ds1wm_data->reset_recover_delay)
  192 + msleep(ds1wm_data->reset_recover_delay);
  193 +
190 194 return 0;
191 195 }
192 196  
... ... @@ -490,6 +494,7 @@
490 494 }
491 495 ds1wm_data->irq = res->start;
492 496 ds1wm_data->int_en_reg_none = (plat->active_high ? DS1WM_INTEN_IAS : 0);
  497 + ds1wm_data->reset_recover_delay = plat->reset_recover_delay;
493 498  
494 499 if (res->flags & IORESOURCE_IRQ_HIGHEDGE)
495 500 irq_set_irq_type(ds1wm_data->irq, IRQ_TYPE_EDGE_RISING);
include/linux/mfd/ds1wm.h
Diff comments   View file @ f607e7f
... ... @@ -3,5 +3,12 @@
3 3 struct ds1wm_driver_data {
4 4 int active_high;
5 5 int clock_rate;
  6 + /* in milliseconds, the amount of time to */
  7 + /* sleep following a reset pulse. Zero */
  8 + /* should work if your bus devices recover*/
  9 + /* time respects the 1-wire spec since the*/
  10 + /* ds1wm implements the precise timings of*/
  11 + /* a reset pulse/presence detect sequence.*/
  12 + unsigned int reset_recover_delay;
6 13 };