[PATCH] w1: ds1wm: add a reset recovery parameter

[Jean-François Dagenais]

This follows the regression on 3.0 reported by Paul Parsons regarding
the removal of the msleep(1) in the ds1wm_reset() function. 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.
---
 drivers/mfd/asic3.c        |    1 +
 drivers/mfd/htc-pasic3.c   |    1 +
 drivers/w1/masters/ds1wm.c |    5 +++++
 include/linux/mfd/ds1wm.h  |    7 +++++++
 4 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/drivers/mfd/asic3.c b/drivers/mfd/asic3.c
index c27fd1f..c71ae09 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 2808bd1..04c7093 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 ad57593..66bf82f 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 be469a3..068044f 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;
 };
-- 
1.7.5.4

Jean-Francois Dagenais 
Software Architect - B.Sc.A


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