Re: [PATCH v9 11/20] gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL

From: Andy Shevchenko
Date: Wed Sep 23 2020 - 12:18:28 EST


On Tue, Sep 22, 2020 at 5:36 AM Kent Gibson <warthog618@xxxxxxxxx> wrote:
>
> Add support for the GPIO_V2_LINE_SET_VALUES_IOCTL.

> +static long linereq_set_values_unlocked(struct linereq *lr,
> + struct gpio_v2_line_values *lv)
> +{
> + DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX);
> + struct gpio_desc **descs;
> + unsigned int i, didx, num_set;
> + int ret;
> +
> + bitmap_zero(vals, GPIO_V2_LINES_MAX);
> + for (num_set = 0, i = 0; i < lr->num_lines; i++) {
> + if (lv->mask & BIT_ULL(i)) {

Similar idea

DECLARE_BITMAP(mask, 64) = BITMAP_FROM_U64(lv->mask);

num_set = bitmap_weight();

for_each_set_bit(i, mask, lr->num_lines)


> + if (!test_bit(FLAG_IS_OUT, &lr->lines[i].desc->flags))
> + return -EPERM;
> + if (lv->bits & BIT_ULL(i))
> + __set_bit(num_set, vals);
> + num_set++;
> + descs = &lr->lines[i].desc;
> + }
> + }
> + if (num_set == 0)
> + return -EINVAL;
> +
> + if (num_set != 1) {
> + /* build compacted desc array and values */
> + descs = kmalloc_array(num_set, sizeof(*descs), GFP_KERNEL);
> + if (!descs)
> + return -ENOMEM;
> + for (didx = 0, i = 0; i < lr->num_lines; i++) {
> + if (lv->mask & BIT_ULL(i)) {
> + descs[didx] = lr->lines[i].desc;
> + didx++;
> + }
> + }
> + }
> + ret = gpiod_set_array_value_complex(false, true, num_set,
> + descs, NULL, vals);
> +
> + if (num_set != 1)
> + kfree(descs);
> + return ret;
> +}
> +
> +static long linereq_set_values(struct linereq *lr, void __user *ip)
> +{
> + struct gpio_v2_line_values lv;
> + int ret;
> +
> + if (copy_from_user(&lv, ip, sizeof(lv)))
> + return -EFAULT;
> +
> + mutex_lock(&lr->config_mutex);
> +
> + ret = linereq_set_values_unlocked(lr, &lv);
> +
> + mutex_unlock(&lr->config_mutex);
> +
> + return ret;
> +}
> +
> static long linereq_set_config_unlocked(struct linereq *lr,
> struct gpio_v2_line_config *lc)
> {
> @@ -889,6 +948,8 @@ static long linereq_ioctl(struct file *file, unsigned int cmd,
>
> if (cmd == GPIO_V2_LINE_GET_VALUES_IOCTL)
> return linereq_get_values(lr, ip);
> + else if (cmd == GPIO_V2_LINE_SET_VALUES_IOCTL)
> + return linereq_set_values(lr, ip);
> else if (cmd == GPIO_V2_LINE_SET_CONFIG_IOCTL)
> return linereq_set_config(lr, ip);
>
> --
> 2.28.0
>


--
With Best Regards,
Andy Shevchenko