* [PATCH 2/2] w1: Disable irqs during 1-wire bus operations, extend 1-wire reset pulse
@ 2012-03-15 22:37 Markus Franke
0 siblings, 0 replies; 5+ messages in thread
From: Markus Franke @ 2012-03-15 22:37 UTC (permalink / raw)
To: linux-kernel; +Cc: gregkh
This patch offers the possibility to disables irqs during w1_write_bit()
and w1_reset_bus() operations as timing requirements are very strict for
the 1-wire bus protocol. Per default interrupts are enabled but can be
disabled via the module parameter "w1_disable_irqs".
Extend 1-wire reset pulse length from 480us to 500us as 480us is the
minimum requirement for the 1-wire reset/presence pulse.
It applies to the current linux kernel git tree.
Signed-off-by: Markus Franke <franm@hrz.tu-chemnitz.de>
---
drivers/w1/w1_io.c | 22 ++++++++++++++++++----
1 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/w1/w1_io.c b/drivers/w1/w1_io.c
index 3135b2c..e10acc2 100644
--- a/drivers/w1/w1_io.c
+++ b/drivers/w1/w1_io.c
@@ -31,6 +31,9 @@
static int w1_delay_parm = 1;
module_param_named(delay_coef, w1_delay_parm, int, 0);
+static int w1_disable_irqs = 0;
+module_param_named(disable_irqs, w1_disable_irqs, int, 0);
+
static u8 w1_crc8_table[] = {
0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,
157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,
@@ -79,6 +82,10 @@ static u8 w1_touch_bit(struct w1_master *dev, int bit)
*/
static void w1_write_bit(struct w1_master *dev, int bit)
{
+ unsigned long flags = 0;
+
+ if(w1_disable_irqs) local_irq_save(flags);
+
if (bit) {
dev->bus_master->write_bit(dev->bus_master->data, 0);
w1_delay(6);
@@ -90,6 +97,8 @@ static void w1_write_bit(struct w1_master *dev, int bit)
dev->bus_master->write_bit(dev->bus_master->data, 1);
w1_delay(10);
}
+
+ if(w1_disable_irqs) local_irq_restore(flags);
}
/**
@@ -158,7 +167,7 @@ EXPORT_SYMBOL_GPL(w1_write_8);
static u8 w1_read_bit(struct w1_master *dev)
{
int result;
- unsigned long flags;
+ unsigned long flags = 0;
/* sample timing is critical here */
local_irq_save(flags);
@@ -318,6 +327,9 @@ EXPORT_SYMBOL_GPL(w1_read_block);
int w1_reset_bus(struct w1_master *dev)
{
int result;
+ unsigned long flags = 0;
+
+ if(w1_disable_irqs) local_irq_save(flags);
if (dev->bus_master->reset_bus)
result = dev->bus_master->reset_bus(dev->bus_master->data) & 0x1;
@@ -330,19 +342,21 @@ int w1_reset_bus(struct w1_master *dev)
* cpu for such a short amount of time AND get it back in
* the maximum amount of time.
*/
- w1_delay(480);
+ w1_delay(500);
dev->bus_master->write_bit(dev->bus_master->data, 1);
w1_delay(70);
result = dev->bus_master->read_bit(dev->bus_master->data) & 0x1;
- /* minmum 70 (above) + 410 = 480 us
+ /* minmum 70 (above) + 430 = 500 us
* There aren't any timing requirements between a reset and
* the following transactions. Sleeping is safe here.
*/
- /* w1_delay(410); min required time */
+ /* w1_delay(430); min required time */
msleep(1);
}
+ if(w1_disable_irqs) local_irq_restore(flags);
+
return result;
}
EXPORT_SYMBOL_GPL(w1_reset_bus);
--
1.7.4.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/2] w1: Disable irqs during 1-wire bus operations, extend 1-wire reset pulse
@ 2012-03-15 22:53 Markus Franke
0 siblings, 0 replies; 5+ messages in thread
From: Markus Franke @ 2012-03-15 22:53 UTC (permalink / raw)
To: linux-kernel; +Cc: gregkh
This patch offers the possibility to disables irqs during w1_write_bit()
and w1_reset_bus() operations as timing requirements are very strict for
the 1-wire bus protocol. Per default interrupts are enabled but can be
disabled via the module parameter "w1_disable_irqs".
Extend 1-wire reset pulse length from 480us to 500us as 480us is the
minimum requirement for the 1-wire reset/presence pulse.
It applies to the current linux kernel git tree.
Signed-off-by: Markus Franke <franm@hrz.tu-chemnitz.de>
---
drivers/w1/w1_io.c | 22 ++++++++++++++++++----
1 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/w1/w1_io.c b/drivers/w1/w1_io.c
index 3135b2c..e10acc2 100644
--- a/drivers/w1/w1_io.c
+++ b/drivers/w1/w1_io.c
@@ -31,6 +31,9 @@
static int w1_delay_parm = 1;
module_param_named(delay_coef, w1_delay_parm, int, 0);
+static int w1_disable_irqs = 0;
+module_param_named(disable_irqs, w1_disable_irqs, int, 0);
+
static u8 w1_crc8_table[] = {
0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,
157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,
@@ -79,6 +82,10 @@ static u8 w1_touch_bit(struct w1_master *dev, int bit)
*/
static void w1_write_bit(struct w1_master *dev, int bit)
{
+ unsigned long flags = 0;
+
+ if(w1_disable_irqs) local_irq_save(flags);
+
if (bit) {
dev->bus_master->write_bit(dev->bus_master->data, 0);
w1_delay(6);
@@ -90,6 +97,8 @@ static void w1_write_bit(struct w1_master *dev, int bit)
dev->bus_master->write_bit(dev->bus_master->data, 1);
w1_delay(10);
}
+
+ if(w1_disable_irqs) local_irq_restore(flags);
}
/**
@@ -158,7 +167,7 @@ EXPORT_SYMBOL_GPL(w1_write_8);
static u8 w1_read_bit(struct w1_master *dev)
{
int result;
- unsigned long flags;
+ unsigned long flags = 0;
/* sample timing is critical here */
local_irq_save(flags);
@@ -318,6 +327,9 @@ EXPORT_SYMBOL_GPL(w1_read_block);
int w1_reset_bus(struct w1_master *dev)
{
int result;
+ unsigned long flags = 0;
+
+ if(w1_disable_irqs) local_irq_save(flags);
if (dev->bus_master->reset_bus)
result = dev->bus_master->reset_bus(dev->bus_master->data) & 0x1;
@@ -330,19 +342,21 @@ int w1_reset_bus(struct w1_master *dev)
* cpu for such a short amount of time AND get it back in
* the maximum amount of time.
*/
- w1_delay(480);
+ w1_delay(500);
dev->bus_master->write_bit(dev->bus_master->data, 1);
w1_delay(70);
result = dev->bus_master->read_bit(dev->bus_master->data) & 0x1;
- /* minmum 70 (above) + 410 = 480 us
+ /* minmum 70 (above) + 430 = 500 us
* There aren't any timing requirements between a reset and
* the following transactions. Sleeping is safe here.
*/
- /* w1_delay(410); min required time */
+ /* w1_delay(430); min required time */
msleep(1);
}
+ if(w1_disable_irqs) local_irq_restore(flags);
+
return result;
}
EXPORT_SYMBOL_GPL(w1_reset_bus);
--
1.7.4.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/2] w1: Disable irqs during 1-wire bus operations, extend 1-wire reset pulse
@ 2012-03-16 21:25 Markus Franke
2012-03-18 21:41 ` Evgeniy Polyakov
0 siblings, 1 reply; 5+ messages in thread
From: Markus Franke @ 2012-03-16 21:25 UTC (permalink / raw)
To: linux-kernel; +Cc: gregkh, Evgeniy Polyakov
This patch offers the possibility to disables irqs during w1_write_bit() and w1_reset_bus() operations as timing requirements are very strict for the 1-wire bus protocol. Per default interrupts are enabled but can be disabled via the module parameter "w1_disable_irqs".
Extend 1-wire reset pulse length from 480us to 500us as 480us is the minimum requirement for the 1-wire reset/presence pulse.
It applies to the current linux kernel git tree.
Signed-off-by: Markus Franke <franm@hrz.tu-chemnitz.de>
---
drivers/w1/w1_io.c | 22 ++++++++++++++++++----
1 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/w1/w1_io.c b/drivers/w1/w1_io.c
index 3135b2c..e10acc2 100644
--- a/drivers/w1/w1_io.c
+++ b/drivers/w1/w1_io.c
@@ -31,6 +31,9 @@
static int w1_delay_parm = 1;
module_param_named(delay_coef, w1_delay_parm, int, 0);
+static int w1_disable_irqs = 0;
+module_param_named(disable_irqs, w1_disable_irqs, int, 0);
+
static u8 w1_crc8_table[] = {
0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,
157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,
@@ -79,6 +82,10 @@ static u8 w1_touch_bit(struct w1_master *dev, int bit)
*/
static void w1_write_bit(struct w1_master *dev, int bit)
{
+ unsigned long flags = 0;
+
+ if(w1_disable_irqs) local_irq_save(flags);
+
if (bit) {
dev->bus_master->write_bit(dev->bus_master->data, 0);
w1_delay(6);
@@ -90,6 +97,8 @@ static void w1_write_bit(struct w1_master *dev, int bit)
dev->bus_master->write_bit(dev->bus_master->data, 1);
w1_delay(10);
}
+
+ if(w1_disable_irqs) local_irq_restore(flags);
}
/**
@@ -158,7 +167,7 @@ EXPORT_SYMBOL_GPL(w1_write_8);
static u8 w1_read_bit(struct w1_master *dev)
{
int result;
- unsigned long flags;
+ unsigned long flags = 0;
/* sample timing is critical here */
local_irq_save(flags);
@@ -318,6 +327,9 @@ EXPORT_SYMBOL_GPL(w1_read_block);
int w1_reset_bus(struct w1_master *dev)
{
int result;
+ unsigned long flags = 0;
+
+ if(w1_disable_irqs) local_irq_save(flags);
if (dev->bus_master->reset_bus)
result = dev->bus_master->reset_bus(dev->bus_master->data) & 0x1;
@@ -330,19 +342,21 @@ int w1_reset_bus(struct w1_master *dev)
* cpu for such a short amount of time AND get it back in
* the maximum amount of time.
*/
- w1_delay(480);
+ w1_delay(500);
dev->bus_master->write_bit(dev->bus_master->data, 1);
w1_delay(70);
result = dev->bus_master->read_bit(dev->bus_master->data) & 0x1;
- /* minmum 70 (above) + 410 = 480 us
+ /* minmum 70 (above) + 430 = 500 us
* There aren't any timing requirements between a reset and
* the following transactions. Sleeping is safe here.
*/
- /* w1_delay(410); min required time */
+ /* w1_delay(430); min required time */
msleep(1);
}
+ if(w1_disable_irqs) local_irq_restore(flags);
+
return result;
}
EXPORT_SYMBOL_GPL(w1_reset_bus);
--
1.7.4.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] w1: Disable irqs during 1-wire bus operations, extend 1-wire reset pulse
2012-03-16 21:25 [PATCH 2/2] w1: Disable irqs during 1-wire bus operations, extend 1-wire reset pulse Markus Franke
@ 2012-03-18 21:41 ` Evgeniy Polyakov
0 siblings, 0 replies; 5+ messages in thread
From: Evgeniy Polyakov @ 2012-03-18 21:41 UTC (permalink / raw)
To: Markus Franke; +Cc: linux-kernel, gregkh
On Fri, Mar 16, 2012 at 10:25:41PM +0100, Markus Franke (markus.franke@s2002.tu-chemnitz.de) wrote:
> This patch offers the possibility to disables irqs during w1_write_bit() and w1_reset_bus() operations as timing requirements are very strict for the 1-wire bus protocol. Per default interrupts are enabled but can be disabled via the module parameter "w1_disable_irqs".
>
> Extend 1-wire reset pulse length from 480us to 500us as 480us is the minimum requirement for the 1-wire reset/presence pulse.
>
> It applies to the current linux kernel git tree.
>
> Signed-off-by: Markus Franke <franm@hrz.tu-chemnitz.de>
Patch looks good, thank you
Greg, please apply
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
--
Evgeniy Polyakov
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 2/2] w1: Disable irqs during 1-wire bus operations, extend 1-wire reset pulse
[not found] <4F860770.70902@hrz.tu-chemnitz.de>
@ 2012-04-11 22:42 ` Markus Franke
0 siblings, 0 replies; 5+ messages in thread
From: Markus Franke @ 2012-04-11 22:42 UTC (permalink / raw)
To: Greg KH; +Cc: linux-kernel, Evgeniy Polyakov
This patch offers the possibility to disables irqs during w1_write_bit() and w1_reset_bus() operations as timing requirements are very strict for the 1-wire bus protocol. Per default interrupts are enabled but can be disabled via the module parameter "w1_disable_irqs".
Extend 1-wire reset pulse length from 480us to 500us as 480us is the minimum requirement for the 1-wire reset/presence pulse.
It applies to the current linux kernel git tree.
Signed-off-by: Markus Franke <franm@hrz.tu-chemnitz.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
---
drivers/w1/w1_io.c | 22 ++++++++++++++++++----
1 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/w1/w1_io.c b/drivers/w1/w1_io.c
index 3135b2c..e10acc2 100644
--- a/drivers/w1/w1_io.c
+++ b/drivers/w1/w1_io.c
@@ -31,6 +31,9 @@
static int w1_delay_parm = 1;
module_param_named(delay_coef, w1_delay_parm, int, 0);
+static int w1_disable_irqs = 0;
+module_param_named(disable_irqs, w1_disable_irqs, int, 0);
+
static u8 w1_crc8_table[] = {
0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,
157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,
@@ -79,6 +82,10 @@ static u8 w1_touch_bit(struct w1_master *dev, int bit)
*/
static void w1_write_bit(struct w1_master *dev, int bit)
{
+ unsigned long flags = 0;
+
+ if(w1_disable_irqs) local_irq_save(flags);
+
if (bit) {
dev->bus_master->write_bit(dev->bus_master->data, 0);
w1_delay(6);
@@ -90,6 +97,8 @@ static void w1_write_bit(struct w1_master *dev, int bit)
dev->bus_master->write_bit(dev->bus_master->data, 1);
w1_delay(10);
}
+
+ if(w1_disable_irqs) local_irq_restore(flags);
}
/**
@@ -158,7 +167,7 @@ EXPORT_SYMBOL_GPL(w1_write_8);
static u8 w1_read_bit(struct w1_master *dev)
{
int result;
- unsigned long flags;
+ unsigned long flags = 0;
/* sample timing is critical here */
local_irq_save(flags);
@@ -318,6 +327,9 @@ EXPORT_SYMBOL_GPL(w1_read_block);
int w1_reset_bus(struct w1_master *dev)
{
int result;
+ unsigned long flags = 0;
+
+ if(w1_disable_irqs) local_irq_save(flags);
if (dev->bus_master->reset_bus)
result = dev->bus_master->reset_bus(dev->bus_master->data) & 0x1;
@@ -330,19 +342,21 @@ int w1_reset_bus(struct w1_master *dev)
* cpu for such a short amount of time AND get it back in
* the maximum amount of time.
*/
- w1_delay(480);
+ w1_delay(500);
dev->bus_master->write_bit(dev->bus_master->data, 1);
w1_delay(70);
result = dev->bus_master->read_bit(dev->bus_master->data) & 0x1;
- /* minmum 70 (above) + 410 = 480 us
+ /* minmum 70 (above) + 430 = 500 us
* There aren't any timing requirements between a reset and
* the following transactions. Sleeping is safe here.
*/
- /* w1_delay(410); min required time */
+ /* w1_delay(430); min required time */
msleep(1);
}
+ if(w1_disable_irqs) local_irq_restore(flags);
+
return result;
}
EXPORT_SYMBOL_GPL(w1_reset_bus);
--
1.7.5.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2012-04-11 22:42 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2012-03-16 21:25 [PATCH 2/2] w1: Disable irqs during 1-wire bus operations, extend 1-wire reset pulse Markus Franke
2012-03-18 21:41 ` Evgeniy Polyakov
[not found] <4F860770.70902@hrz.tu-chemnitz.de>
2012-04-11 22:42 ` Markus Franke
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2012-03-15 22:53 Markus Franke
2012-03-15 22:37 Markus Franke
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