lkml.org 
[lkml]   [2014]   [Sep]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v5 4/4] gpio: add support for the Diolan DLN-2 USB GPIO driver
On Fri, Sep 19, 2014 at 11:22:45PM +0300, Octavian Purdila wrote:

> +struct dln2_gpio {
> + struct platform_device *pdev;
> + struct gpio_chip gpio;
> +
> + /*
> + * Cache pin direction to save us one transfer, since the
> + * hardware has separate commands to read the in and out
> + * values. Bit set for out, bit clear for in.
> + */
> + DECLARE_BITMAP(pin_dir, DLN2_GPIO_MAX_PINS);

Using the more common name output_enabled might be preferred? Then you
can even get rid of (part of) the comment.

> +
> + DECLARE_BITMAP(irqs_masked, DLN2_GPIO_MAX_PINS);
> + DECLARE_BITMAP(irqs_enabled, DLN2_GPIO_MAX_PINS);
> + DECLARE_BITMAP(irqs_pending, DLN2_GPIO_MAX_PINS);
> + struct dln2_irq_work *irq_work;
> +};

[...]

> +#define DLN2_GPIO_DIRECTION_IN 0
> +#define DLN2_GPIO_DIRECTION_OUT 1
> +
> +static int dln2_gpio_request(struct gpio_chip *chip, unsigned offset)
> +{
> + struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio);
> + struct dln2_gpio_pin req = {
> + .pin = cpu_to_le16(offset),
> + };
> + struct dln2_gpio_pin_val rsp;
> + int len = sizeof(rsp);
> + int ret;
> +
> + ret = dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_ENABLE, offset);
> + if (ret < 0)
> + return ret;
> +
> + /* cache the pin direction */
> + ret = dln2_transfer(dln2->pdev, DLN2_GPIO_PIN_GET_DIRECTION,
> + &req, sizeof(req), &rsp, &len);
> + if (ret < 0)
> + return ret;
> + if (len < sizeof(rsp) || req.pin != rsp.pin)
> + return -EPROTO;

Disable the pin?

> +
> + switch (rsp.value) {
> + case DLN2_GPIO_DIRECTION_IN:
> + clear_bit(offset, dln2->pin_dir);
> + return 0;
> + case DLN2_GPIO_DIRECTION_OUT:
> + set_bit(offset, dln2->pin_dir);
> + return 0;
> + default:
> + return -EPROTO;

Disable the pin?

> + }
> +}

[...]

> +static struct platform_driver dln2_gpio_driver = {
> + .driver.name = "dln2-gpio",
> + .driver.owner = THIS_MODULE,

No need to set the owner field when using the module_platform_driver
macro.

> + .probe = dln2_gpio_probe,
> + .remove = dln2_gpio_remove,
> +};
> +
> +module_platform_driver(dln2_gpio_driver);
> +
> +MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com");
> +MODULE_DESCRIPTION("Driver for the Diolan DLN2 GPIO interface");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:dln2-gpio");

Johan


\
 
 \ /
  Last update: 2014-09-24 15:21    [W:0.122 / U:0.248 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site