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Message-ID: <20100407085116.GD2962@sortiz.org>
Date: Wed, 7 Apr 2010 10:51:17 +0200
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: Ensure WM831x charger interrupts are
acknowledged when suspending
Hi Mark,
On Mon, Apr 05, 2010 at 04:14:18PM +0100, Mark Brown wrote:
> The charger interrupts on the WM831x are unconditionally a wake source
> for the system. If the power driver is not able to monitor them (for
> example, due to the IRQ line not having been wired up on the system)
> then any charger interrupt will prevent the system suspending for any
> meaningful amount of time since nothing will ack them.
>
> Avoid this issue by manually acknowledging these interrupts when we
> suspend the WM831x core device if they are masked. If software is
> actually using the interrupts then they will be unmasked and this
> change will have no effect.
Patch applied, many thanks.
Cheers,
Samuel.
> Signed-off-by: Mark Brown <broonie@...nsource.wolfsonmicro.com>
> ---
> drivers/mfd/wm831x-core.c | 47 +++++++++++++++++++++++++++++++++++++++
> include/linux/mfd/wm831x/core.h | 5 ++-
> 2 files changed, 50 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mfd/wm831x-core.c b/drivers/mfd/wm831x-core.c
> index f8a8cdf..8152529 100644
> --- a/drivers/mfd/wm831x-core.c
> +++ b/drivers/mfd/wm831x-core.c
> @@ -1493,6 +1493,7 @@ static int wm831x_device_init(struct wm831x *wm831x, unsigned long id, int irq)
> case WM8310:
> parent = WM8310;
> wm831x->num_gpio = 16;
> + wm831x->charger_irq_wake = 1;
> if (rev > 0) {
> wm831x->has_gpio_ena = 1;
> wm831x->has_cs_sts = 1;
> @@ -1504,6 +1505,7 @@ static int wm831x_device_init(struct wm831x *wm831x, unsigned long id, int irq)
> case WM8311:
> parent = WM8311;
> wm831x->num_gpio = 16;
> + wm831x->charger_irq_wake = 1;
> if (rev > 0) {
> wm831x->has_gpio_ena = 1;
> wm831x->has_cs_sts = 1;
> @@ -1515,6 +1517,7 @@ static int wm831x_device_init(struct wm831x *wm831x, unsigned long id, int irq)
> case WM8312:
> parent = WM8312;
> wm831x->num_gpio = 16;
> + wm831x->charger_irq_wake = 1;
> if (rev > 0) {
> wm831x->has_gpio_ena = 1;
> wm831x->has_cs_sts = 1;
> @@ -1653,6 +1656,42 @@ static void wm831x_device_exit(struct wm831x *wm831x)
> kfree(wm831x);
> }
>
> +static int wm831x_device_suspend(struct wm831x *wm831x)
> +{
> + int reg, mask;
> +
> + /* If the charger IRQs are a wake source then make sure we ack
> + * them even if they're not actively being used (eg, no power
> + * driver or no IRQ line wired up) then acknowledge the
> + * interrupts otherwise suspend won't last very long.
> + */
> + if (wm831x->charger_irq_wake) {
> + reg = wm831x_reg_read(wm831x, WM831X_INTERRUPT_STATUS_2_MASK);
> +
> + mask = WM831X_CHG_BATT_HOT_EINT |
> + WM831X_CHG_BATT_COLD_EINT |
> + WM831X_CHG_BATT_FAIL_EINT |
> + WM831X_CHG_OV_EINT | WM831X_CHG_END_EINT |
> + WM831X_CHG_TO_EINT | WM831X_CHG_MODE_EINT |
> + WM831X_CHG_START_EINT;
> +
> + /* If any of the interrupts are masked read the statuses */
> + if (reg & mask)
> + reg = wm831x_reg_read(wm831x,
> + WM831X_INTERRUPT_STATUS_2);
> +
> + if (reg & mask) {
> + dev_info(wm831x->dev,
> + "Acknowledging masked charger IRQs: %x\n",
> + reg & mask);
> + wm831x_reg_write(wm831x, WM831X_INTERRUPT_STATUS_2,
> + reg & mask);
> + }
> + }
> +
> + return 0;
> +}
> +
> static int wm831x_i2c_read_device(struct wm831x *wm831x, unsigned short reg,
> int bytes, void *dest)
> {
> @@ -1727,6 +1766,13 @@ static int wm831x_i2c_remove(struct i2c_client *i2c)
> return 0;
> }
>
> +static int wm831x_i2c_suspend(struct i2c_client *i2c)
> +{
> + struct wm831x *wm831x = i2c_get_clientdata(i2c);
> +
> + return wm831x_device_suspend(wm831x);
> +}
> +
> static const struct i2c_device_id wm831x_i2c_id[] = {
> { "wm8310", WM8310 },
> { "wm8311", WM8311 },
> @@ -1744,6 +1790,7 @@ static struct i2c_driver wm831x_i2c_driver = {
> },
> .probe = wm831x_i2c_probe,
> .remove = wm831x_i2c_remove,
> + .suspend = wm831x_i2c_suspend,
> .id_table = wm831x_i2c_id,
> };
>
> diff --git a/include/linux/mfd/wm831x/core.h b/include/linux/mfd/wm831x/core.h
> index 5915f6e..eb5bd4e 100644
> --- a/include/linux/mfd/wm831x/core.h
> +++ b/include/linux/mfd/wm831x/core.h
> @@ -256,8 +256,9 @@ struct wm831x {
> int irq_masks_cache[WM831X_NUM_IRQ_REGS]; /* Cached hardware value */
>
> /* Chip revision based flags */
> - unsigned has_gpio_ena:1; /* Has GPIO enable bit */
> - unsigned has_cs_sts:1; /* Has current sink status bit */
> + unsigned has_gpio_ena:1; /* Has GPIO enable bit */
> + unsigned has_cs_sts:1; /* Has current sink status bit */
> + unsigned charger_irq_wake:1; /* Are charger IRQs a wake source? */
>
> int num_gpio;
>
> --
> 1.7.0.3
>
--
Intel Open Source Technology Centre
http://oss.intel.com/
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