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From: Mark Brown on 23 Feb 2010 06:10
Use the completion interrupt generated by the device rather than
polling for conversions to complete. As a backup we still check
the state of the AUXADC if we don't get a completion, mostly for
systems that don't have the WM8350 interrupt infrastructure hooked
up.

Signed-off-by: Mark Brown <broonie(a)opensource.wolfsonmicro.com>
---
drivers/mfd/wm8350-core.c | 35 +++++++++++++++++++++++++++++------
include/linux/mfd/wm8350/core.h | 2 ++
2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/drivers/mfd/wm8350-core.c b/drivers/mfd/wm8350-core.c
index 9a970bd..bd75807 100644
--- a/drivers/mfd/wm8350-core.c
+++ b/drivers/mfd/wm8350-core.c
@@ -339,7 +339,6 @@ EXPORT_SYMBOL_GPL(wm8350_reg_unlock);
int wm8350_read_auxadc(struct wm8350 *wm8350, int channel, int scale, int vref)
{
u16 reg, result = 0;
- int tries = 5;

if (channel < WM8350_AUXADC_AUX1 || channel > WM8350_AUXADC_TEMP)
return -EINVAL;
@@ -363,12 +362,13 @@ int wm8350_read_auxadc(struct wm8350 *wm8350, int channel, int scale, int vref)
reg |= 1 << channel | WM8350_AUXADC_POLL;
wm8350_reg_write(wm8350, WM8350_DIGITISER_CONTROL_1, reg);

- do {
- schedule_timeout_interruptible(1);
- reg = wm8350_reg_read(wm8350, WM8350_DIGITISER_CONTROL_1);
- } while ((reg & WM8350_AUXADC_POLL) && --tries);
+ /* We ignore the result of the completion and just check for a
+ * conversion result, allowing us to soldier on if the IRQ
+ * infrastructure is not set up for the chip. */
+ wait_for_completion_timeout(&wm8350->auxadc_done, msecs_to_jiffies(5));

- if (!tries)
+ reg = wm8350_reg_read(wm8350, WM8350_DIGITISER_CONTROL_1);
+ if (reg & WM8350_AUXADC_POLL)
dev_err(wm8350->dev, "adc chn %d read timeout\n", channel);
else
result = wm8350_reg_read(wm8350,
@@ -385,6 +385,15 @@ int wm8350_read_auxadc(struct wm8350 *wm8350, int channel, int scale, int vref)
}
EXPORT_SYMBOL_GPL(wm8350_read_auxadc);

+static irqreturn_t wm8350_auxadc_irq(int irq, void *irq_data)
+{
+ struct wm8350 *wm8350 = irq_data;
+
+ complete(&wm8350->auxadc_done);
+
+ return IRQ_HANDLED;
+}
+
/*
* Cache is always host endian.
*/
@@ -682,11 +691,22 @@ int wm8350_device_init(struct wm8350 *wm8350, int irq,
}

mutex_init(&wm8350->auxadc_mutex);
+ init_completion(&wm8350->auxadc_done);

ret = wm8350_irq_init(wm8350, irq, pdata);
if (ret < 0)
goto err;

+ if (wm8350->irq_base) {
+ ret = request_threaded_irq(wm8350->irq_base +
+ WM8350_IRQ_AUXADC_DATARDY,
+ NULL, wm8350_auxadc_irq, 0,
+ "auxadc", wm8350);
+ if (ret < 0)
+ dev_warn(wm8350->dev,
+ "Failed to request AUXADC IRQ: %d\n", ret);
+ }
+
if (pdata && pdata->init) {
ret = pdata->init(wm8350);
if (ret != 0) {
@@ -736,6 +756,9 @@ void wm8350_device_exit(struct wm8350 *wm8350)
platform_device_unregister(wm8350->gpio.pdev);
platform_device_unregister(wm8350->codec.pdev);

+ if (wm8350->irq_base)
+ free_irq(wm8350->irq_base + WM8350_IRQ_AUXADC_DATARDY, wm8350);
+
wm8350_irq_exit(wm8350);

kfree(wm8350->reg_cache);
diff --git a/include/linux/mfd/wm8350/core.h b/include/linux/mfd/wm8350/core.h
index fae08aa..98fcc97 100644
--- a/include/linux/mfd/wm8350/core.h
+++ b/include/linux/mfd/wm8350/core.h
@@ -16,6 +16,7 @@
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>
+#include <linux/completion.h>

#include <linux/mfd/wm8350/audio.h>
#include <linux/mfd/wm8350/gpio.h>
@@ -621,6 +622,7 @@ struct wm8350 {
u16 *reg_cache;

struct mutex auxadc_mutex;
+ struct completion auxadc_done;

/* Interrupt handling */
struct mutex irq_lock;
--
1.7.0

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Next: [patch] uwb: remove duplicate cpu_to_le16()