linux-kernel - Re: [PATCH] i2c: allow specifying separate wakeup interrupt in device tree

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Message-ID: <55BB54B1.80603@ti.com>
Date:	Fri, 31 Jul 2015 16:27:53 +0530
From:	Vignesh R <vigneshr@...com>
To:	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	Wolfram Sang <wsa@...-dreams.de>
CC:	Mika Westerberg <mika.westerberg@...ux.intel.com>,
	"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
	Ulf Hansson <ulf.hansson@...aro.org>,
	Tony Lindgren <tony@...mide.com>,
	Rob Herring <robh+dt@...nel.org>,
	Mark Rutland <mark.rutland@....com>,
	"linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] i2c: allow specifying separate wakeup interrupt in device
 tree



On 07/31/2015 01:44 AM, Dmitry Torokhov wrote:
> Instead of having each i2c driver individually parse device tree data in
> case it or platform supports separate wakeup interrupt, and handle
> enabling and disabling wakeup interrupts in their power management
> routines, let's have i2c core do that for us.
> 
> Platforms wishing to specify separate wakeup interrupt for the device
> should use named interrupt syntax in their DTSes:
> 
> 	interrupt-parent = <&intc1>;
> 	interrupts = <5 0>, <6 0>;
> 	interrupt-names = "irq", "wakeup";
> 
> This patch is inspired by work done by Vignesh R <vigneshr@...com> for
> pixcir_i2c_ts driver.
> 
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>

Tested this patch on am437x-gp-evm with pixcir_i2c_ts as the wakeup
source. I was able to wakeup from suspend both as built-in and as a
module (No changes were done to pixcir_i2c_ts driver).

Tested-by: Vignesh R <vigneshr@...com>

> ---
>  drivers/i2c/i2c-core.c | 46 ++++++++++++++++++++++++++++++++++++++++------
>  1 file changed, 40 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index e6d4935..19e7a17 100644
> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -47,6 +47,7 @@
>  #include <linux/rwsem.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/pm_domain.h>
> +#include <linux/pm_wakeirq.h>
>  #include <linux/acpi.h>
>  #include <linux/jump_label.h>
>  #include <asm/uaccess.h>
> @@ -639,11 +640,13 @@ static int i2c_device_probe(struct device *dev)
>  	if (!client->irq) {
>  		int irq = -ENOENT;
>  
> -		if (dev->of_node)
> -			irq = of_irq_get(dev->of_node, 0);
> -		else if (ACPI_COMPANION(dev))
> +		if (dev->of_node) {
> +			irq = of_irq_get_byname(dev->of_node, "irq");
> +			if (irq == -EINVAL || irq == -ENODATA)
> +				irq = of_irq_get(dev->of_node, 0);
> +		} else if (ACPI_COMPANION(dev)) {
>  			irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
> -
> +		}
>  		if (irq == -EPROBE_DEFER)
>  			return irq;
>  		if (irq < 0)
> @@ -659,20 +662,47 @@ static int i2c_device_probe(struct device *dev)
>  	if (!device_can_wakeup(&client->dev))
>  		device_init_wakeup(&client->dev,
>  					client->flags & I2C_CLIENT_WAKE);
> +
> +	if (device_can_wakeup(&client->dev)) {
> +		int wakeirq = -ENOENT;
> +
> +		if (dev->of_node) {
> +			wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
> +			if (wakeirq == -EPROBE_DEFER)
> +				return wakeirq;
> +		}
> +
> +		if (wakeirq > 0 && wakeirq != client->irq)
> +			status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);
> +		else if (client->irq > 0)
> +			status = dev_pm_set_wake_irq(dev, wakeirq);
> +		else
> +			status = 0;
> +
> +		if (status)
> +			dev_warn(&client->dev, "failed to set up wakeup irq");
> +	}
> +
>  	dev_dbg(dev, "probe\n");
>  
>  	status = of_clk_set_defaults(dev->of_node, false);
>  	if (status < 0)
> -		return status;
> +		goto err_clear_wakeup_irq;
>  
>  	status = dev_pm_domain_attach(&client->dev, true);
>  	if (status != -EPROBE_DEFER) {
>  		status = driver->probe(client, i2c_match_id(driver->id_table,
>  					client));
>  		if (status)
> -			dev_pm_domain_detach(&client->dev, true);
> +			goto err_detach_pm_domain;
>  	}
>  
> +	return 0;
> +
> +err_detach_pm_domain:
> +	dev_pm_domain_detach(&client->dev, true);
> +err_clear_wakeup_irq:
> +	dev_pm_clear_wake_irq(&client->dev);
>  	return status;
>  }
>  
> @@ -692,6 +722,10 @@ static int i2c_device_remove(struct device *dev)
>  	}
>  
>  	dev_pm_domain_detach(&client->dev, true);
> +
> +	dev_pm_clear_wake_irq(&client->dev);
> +	device_init_wakeup(&client->dev, 0);
> +
>  	return status;
>  }
>  
> 

-- 
Regards
Vignesh
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