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From:   Kent Gibson <warthog618@gmail.com>
To:     linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org,
        bgolaszewski@baylibre.com, linus.walleij@linaro.org
Cc:     Kent Gibson <warthog618@gmail.com>
Subject: [PATCH v4 11/20] gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL
Date:   Fri, 14 Aug 2020 11:02:48 +0800
Message-Id: <20200814030257.135463-12-warthog618@gmail.com>
In-Reply-To: <20200814030257.135463-1-warthog618@gmail.com>
References: <20200814030257.135463-1-warthog618@gmail.com>
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Add support for the GPIO_V2_LINE_SET_VALUES_IOCTL.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
---
 drivers/gpio/gpiolib-cdev.c | 67 +++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 04472c2b6678..de88b7a5ba0f 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -811,6 +811,71 @@ static long line_get_values(struct line *line, void __user *ip)
 	return 0;
 }
 
+static long line_set_values_locked(struct line *line,
+				   struct gpio_v2_line_values *lv)
+{
+	DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX);
+	struct gpio_desc **descs;
+	int ret, i, didx, num_set = 0;
+
+	bitmap_zero(vals, GPIO_V2_LINES_MAX);
+	for (i = 0; i < line->num_descs; i++) {
+		if (lv->mask & BIT_ULL(i)) {
+			if (!test_bit(FLAG_IS_OUT, &line->descs[i]->flags))
+				return -EPERM;
+			if (lv->bits & BIT_ULL(i))
+				__set_bit(num_set, vals);
+			num_set++;
+		}
+	}
+	if (num_set == 0)
+		return -EINVAL;
+
+	if (num_set == line->num_descs)
+		/* Reuse the array setting function */
+		return gpiod_set_array_value_complex(false,
+						     true,
+						     line->num_descs,
+						     line->descs,
+						     NULL,
+						     vals);
+
+	/* build compacted desc array and values */
+	descs = kmalloc_array(num_set, sizeof(*descs), GFP_KERNEL);
+	for (didx = 0, i = 0; i < line->num_descs; i++) {
+		if (lv->mask & BIT_ULL(i)) {
+			descs[didx] = line->descs[i];
+			didx++;
+		}
+	}
+	ret = gpiod_set_array_value_complex(false,
+					    true,
+					    num_set,
+					    descs,
+					    NULL,
+					    vals);
+
+	kfree(descs);
+	return ret;
+}
+
+static long line_set_values(struct line *line, void __user *ip)
+{
+	struct gpio_v2_line_values lv;
+	int ret;
+
+	if (copy_from_user(&lv, ip, sizeof(lv)))
+		return -EFAULT;
+
+	mutex_lock(&line->config_mutex);
+
+	ret = line_set_values_locked(line, &lv);
+
+	mutex_unlock(&line->config_mutex);
+
+	return ret;
+}
+
 static long line_set_config_locked(struct line *line,
 				   struct gpio_v2_line_config *lc)
 {
@@ -880,6 +945,8 @@ static long line_ioctl(struct file *file, unsigned int cmd,
 
 	if (cmd == GPIO_V2_LINE_GET_VALUES_IOCTL)
 		return line_get_values(line, ip);
+	else if (cmd == GPIO_V2_LINE_SET_VALUES_IOCTL)
+		return line_set_values(line, ip);
 	else if (cmd == GPIO_V2_LINE_SET_CONFIG_IOCTL)
 		return line_set_config(line, ip);
 
-- 
2.28.0