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authorJean-Fran├žois Dagenais <dagenaisj@sonatest.com>2011-07-08 15:39:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-08 21:14:44 -0700
commitf607e7fc5fb94d92030c4527287e9c149ddf9e65 (patch)
tree49ac9020b87f028e947580425fef84222332fdf8
parent453a9bf347f1e22a5bb3605ced43b2366921221d (diff)
downloadlinux-linaro-f607e7fc5fb94d92030c4527287e9c149ddf9e65.tar.gz
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-Fran├žois 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>
-rw-r--r--drivers/mfd/asic3.c1
-rw-r--r--drivers/mfd/htc-pasic3.c1
-rw-r--r--drivers/w1/masters/ds1wm.c5
-rw-r--r--include/linux/mfd/ds1wm.h7
4 files changed, 14 insertions, 0 deletions
diff --git a/drivers/mfd/asic3.c b/drivers/mfd/asic3.c
index c27fd1fc3b8..c71ae09430c 100644
--- a/drivers/mfd/asic3.c
+++ b/drivers/mfd/asic3.c
@@ -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[] = {
diff --git a/drivers/mfd/htc-pasic3.c b/drivers/mfd/htc-pasic3.c
index 2808bd125d1..04c7093d649 100644
--- a/drivers/mfd/htc-pasic3.c
+++ b/drivers/mfd/htc-pasic3.c
@@ -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 = {
diff --git a/drivers/w1/masters/ds1wm.c b/drivers/w1/masters/ds1wm.c
index ad57593d224..a0c8965c1a7 100644
--- a/drivers/w1/masters/ds1wm.c
+++ b/drivers/w1/masters/ds1wm.c
@@ -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);
diff --git a/include/linux/mfd/ds1wm.h b/include/linux/mfd/ds1wm.h
index be469a357cb..38a372a0e28 100644
--- a/include/linux/mfd/ds1wm.h
+++ b/include/linux/mfd/ds1wm.h
@@ -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;
};