Re: [PATCH v3 1/1] rc: Add support for GPIO based IR Receiver driver.

From: Jarod Wilson
Date: Mon Apr 23 2012 - 16:11:59 EST


On Tue, Feb 28, 2012 at 11:21:40AM +0530, Ravi Kumar V wrote:
> Adds GPIO based IR Receiver driver. It decodes signals using decoders
> available in rc framework.

Been meaning to look at this, but it looks like its already merged
upstream. Just one question though, inlined below.

> --- /dev/null
> +++ b/drivers/media/rc/gpio-ir-recv.c
> @@ -0,0 +1,205 @@
> +/* Copyright (c) 2012, Code Aurora Forum. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/gpio.h>
> +#include <linux/slab.h>
> +#include <linux/platform_device.h>
> +#include <linux/irq.h>
> +#include <media/rc-core.h>
> +#include <media/gpio-ir-recv.h>
> +
> +#define GPIO_IR_DRIVER_NAME "gpio-rc-recv"
> +#define GPIO_IR_DEVICE_NAME "gpio_ir_recv"
> +
> +struct gpio_rc_dev {
> + struct rc_dev *rcdev;
> + unsigned int gpio_nr;
> + bool active_low;
> +};
> +
> +static irqreturn_t gpio_ir_recv_irq(int irq, void *dev_id)
> +{
> + struct gpio_rc_dev *gpio_dev = dev_id;
> + unsigned int gval;
> + int rc = 0;
> + enum raw_event_type type = IR_SPACE;
> +
> + gval = gpio_get_value_cansleep(gpio_dev->gpio_nr);
> +
> + if (gval < 0)
> + goto err_get_value;
> +
> + if (gpio_dev->active_low)
> + gval = !gval;
> +
> + if (gval == 1)
> + type = IR_PULSE;

What happens if gval is > 1?

> + rc = ir_raw_event_store_edge(gpio_dev->rcdev, type);
> + if (rc < 0)
> + goto err_get_value;
> +
> + ir_raw_event_handle(gpio_dev->rcdev);
> +
> +err_get_value:
> + return IRQ_HANDLED;
> +}

Looks like you'll store a space any time you get gval > 1, which may or
may not be intended here...


--
Jarod Wilson
jarod@xxxxxxxxxx

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