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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>
This commit is contained in:
Jean-François Dagenais 2011-07-08 15:39:44 -07:00 committed by Linus Torvalds
parent 453a9bf347
commit f607e7fc5f
4 changed files with 14 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/mfd/asic3.c
View File

@ -619,6 +619,7 @@ static void asic3_clk_disable(struct asic3 *asic, struct asic3_clk *clk)
/* MFD cells (SPI, PWM, LED, DS1WM, MMC) */
static struct ds1wm_driver_data ds1wm_pdata = {
.active_high = 1,
.reset_recover_delay = 1,
};
static struct resource ds1wm_resources[] = {

1
drivers/mfd/htc-pasic3.c
View File

@ -99,6 +99,7 @@ static int ds1wm_disable(struct platform_device *pdev)
static struct ds1wm_driver_data ds1wm_pdata = {
.active_high = 0,
.reset_recover_delay = 1,
};
static struct resource ds1wm_resources[] __initdata = {

5
drivers/w1/masters/ds1wm.c
View File

@ -109,6 +109,7 @@ struct ds1wm_data {
/* byte to write that makes all intr disabled, */
/* considering active_state (IAS) (optimization) */
u8 int_en_reg_none;
unsigned int reset_recover_delay; /* see ds1wm.h */
};
static inline void ds1wm_write_register(struct ds1wm_data *ds1wm_data, u32 reg,
@ -187,6 +188,9 @@ static int ds1wm_reset(struct ds1wm_data *ds1wm_data)
return 1;
}
if (ds1wm_data->reset_recover_delay)
msleep(ds1wm_data->reset_recover_delay);
return 0;
}
@ -490,6 +494,7 @@ static int ds1wm_probe(struct platform_device *pdev)
}
ds1wm_data->irq = res->start;
ds1wm_data->int_en_reg_none = (plat->active_high ? DS1WM_INTEN_IAS : 0);
ds1wm_data->reset_recover_delay = plat->reset_recover_delay;
if (res->flags & IORESOURCE_IRQ_HIGHEDGE)
irq_set_irq_type(ds1wm_data->irq, IRQ_TYPE_EDGE_RISING);

7
include/linux/mfd/ds1wm.h
View File

@ -3,4 +3,11 @@
struct ds1wm_driver_data {
int active_high;
int clock_rate;
/* in milliseconds, the amount of time to */
/* sleep following a reset pulse. Zero */
/* should work if your bus devices recover*/
/* time respects the 1-wire spec since the*/
/* ds1wm implements the precise timings of*/
/* a reset pulse/presence detect sequence.*/
unsigned int reset_recover_delay;
};