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Date: Mon, 1 Mar 2010 00:05:00 +0100
From: Samuel Ortiz <sameo@...ux.intel.com>
To: Mark Brown <broonie@...nsource.wolfsonmicro.com>
Cc: linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] mfd: Use completion interrupt for WM831x AUXADC
On Tue, Feb 23, 2010 at 11:08:06AM +0000, Mark Brown wrote:
> Use the completion interrupt generated by the device rather than
> polling for conversions to complete. As a backup we still check
> the status of the AUXADC if we don't get a completion, mostly for
> systems that don't have the WM831x interrupt infrastructure hooked
> up.
Patch applied to my for-next branch, thanks a lot.
Cheers,
Samuel.
> Also reduce the timeout for completion of conversions to 5ms from
> the previous 10ms, the lower timeout should be sufficient.
>
> Signed-off-by: Mark Brown <broonie@...nsource.wolfsonmicro.com>
> ---
> drivers/mfd/wm831x-core.c | 36 +++++++++++++++++++++++++++++-------
> include/linux/mfd/wm831x/core.h | 2 ++
> 2 files changed, 31 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/mfd/wm831x-core.c b/drivers/mfd/wm831x-core.c
> index c428d9f..07101e9 100644
> --- a/drivers/mfd/wm831x-core.c
> +++ b/drivers/mfd/wm831x-core.c
> @@ -321,7 +321,6 @@ EXPORT_SYMBOL_GPL(wm831x_set_bits);
> */
> int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)
> {
> - int tries = 10;
> int ret, src;
>
> mutex_lock(&wm831x->auxadc_lock);
> @@ -349,13 +348,14 @@ int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)
> goto disable;
> }
>
> - do {
> - msleep(1);
> + /* Ignore the result to allow us to soldier on without IRQ hookup */
> + wait_for_completion_timeout(&wm831x->auxadc_done, msecs_to_jiffies(5));
>
> - ret = wm831x_reg_read(wm831x, WM831X_AUXADC_CONTROL);
> - if (ret < 0)
> - ret = WM831X_AUX_CVT_ENA;
> - } while ((ret & WM831X_AUX_CVT_ENA) && --tries);
> + ret = wm831x_reg_read(wm831x, WM831X_AUXADC_CONTROL);
> + if (ret < 0) {
> + dev_err(wm831x->dev, "AUXADC status read failed: %d\n", ret);
> + goto disable;
> + }
>
> if (ret & WM831X_AUX_CVT_ENA) {
> dev_err(wm831x->dev, "Timed out reading AUXADC\n");
> @@ -390,6 +390,15 @@ out:
> }
> EXPORT_SYMBOL_GPL(wm831x_auxadc_read);
>
> +static irqreturn_t wm831x_auxadc_irq(int irq, void *irq_data)
> +{
> + struct wm831x *wm831x = irq_data;
> +
> + complete(&wm831x->auxadc_done);
> +
> + return IRQ_HANDLED;
> +}
> +
> /**
> * wm831x_auxadc_read_uv: Read a voltage from the WM831x AUXADC
> *
> @@ -1411,6 +1420,7 @@ static int wm831x_device_init(struct wm831x *wm831x, unsigned long id, int irq)
> mutex_init(&wm831x->io_lock);
> mutex_init(&wm831x->key_lock);
> mutex_init(&wm831x->auxadc_lock);
> + init_completion(&wm831x->auxadc_done);
> dev_set_drvdata(wm831x->dev, wm831x);
>
> ret = wm831x_reg_read(wm831x, WM831X_PARENT_ID);
> @@ -1523,6 +1533,16 @@ static int wm831x_device_init(struct wm831x *wm831x, unsigned long id, int irq)
> if (ret != 0)
> goto err;
>
> + if (wm831x->irq_base) {
> + ret = request_threaded_irq(wm831x->irq_base +
> + WM831X_IRQ_AUXADC_DATA,
> + NULL, wm831x_auxadc_irq, 0,
> + "auxadc", wm831x);
> + if (ret < 0)
> + dev_err(wm831x->dev, "AUXADC IRQ request failed: %d\n",
> + ret);
> + }
> +
> /* The core device is up, instantiate the subdevices. */
> switch (parent) {
> case WM8310:
> @@ -1593,6 +1613,8 @@ static void wm831x_device_exit(struct wm831x *wm831x)
> {
> wm831x_otp_exit(wm831x);
> mfd_remove_devices(wm831x->dev);
> + if (wm831x->irq_base)
> + free_irq(wm831x->irq_base + WM831X_IRQ_AUXADC_DATA, wm831x);
> wm831x_irq_exit(wm831x);
> kfree(wm831x);
> }
> diff --git a/include/linux/mfd/wm831x/core.h b/include/linux/mfd/wm831x/core.h
> index 53580b5..5915f6e 100644
> --- a/include/linux/mfd/wm831x/core.h
> +++ b/include/linux/mfd/wm831x/core.h
> @@ -15,6 +15,7 @@
> #ifndef __MFD_WM831X_CORE_H__
> #define __MFD_WM831X_CORE_H__
>
> +#include <linux/completion.h>
> #include <linux/interrupt.h>
>
> /*
> @@ -261,6 +262,7 @@ struct wm831x {
> int num_gpio;
>
> struct mutex auxadc_lock;
> + struct completion auxadc_done;
>
> /* The WM831x has a security key blocking access to certain
> * registers. The mutex is taken by the accessors for locking
> --
> 1.7.0
>
--
Intel Open Source Technology Centre
http://oss.intel.com/
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