linux-kernel - [PATCH v2 09/18] gpiolib: cdev: support GPIOLINE_SET_VALUES

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Message-Id: <20200725041955.9985-10-warthog618@gmail.com>
Date:   Sat, 25 Jul 2020 12:19:46 +0800
From:   Kent Gibson <warthog618@...il.com>
To:     linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org,
        bgolaszewski@...libre.com, linus.walleij@...aro.org
Cc:     Kent Gibson <warthog618@...il.com>
Subject: [PATCH v2 09/18] gpiolib: cdev: support GPIOLINE_SET_VALUES_IOCTL

Add support for the GPIOLINE_SET_VALUES_IOCTL.

Signed-off-by: Kent Gibson <warthog618@...il.com>
---
 drivers/gpio/gpiolib-cdev.c | 66 +++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 4822cb10aa40..0482a16388a0 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -785,6 +785,70 @@ static long line_get_values(struct line *line, void __user *ip)
 	return 0;
 }
 
+static long line_set_values_locked(struct line *line,
+				   struct gpioline_set_values *lsv)
+{
+	unsigned long *vals = (unsigned long *)lsv->bits;
+	unsigned long *mask = (unsigned long *)lsv->mask;
+	struct gpio_desc **descs;
+	int ret, i, didx, num_set = 0;
+
+	for (i = 0; i < line->num_descs; i++) {
+		if (test_bit(i, mask)) {
+			if (!test_bit(FLAG_IS_OUT, &line->descs[i]->flags))
+				return -EPERM;
+			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 (test_bit(i, mask)) {
+			descs[didx] = line->descs[i];
+			assign_bit(didx, vals, test_bit(i, vals));
+			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 gpioline_set_values lsv;
+	int ret;
+
+	if (copy_from_user(&lsv, ip, sizeof(lsv)))
+		return -EFAULT;
+
+	mutex_lock(&line->config_mutex);
+
+	ret = line_set_values_locked(line, &lsv);
+
+	mutex_unlock(&line->config_mutex);
+
+	return ret;
+}
+
 static long line_set_config_locked(struct line *line,
 				   struct gpioline_config *lc)
 {
@@ -853,6 +917,8 @@ static long line_ioctl(struct file *file, unsigned int cmd,
 
 	if (cmd == GPIOLINE_GET_VALUES_IOCTL)
 		return line_get_values(line, ip);
+	else if (cmd == GPIOLINE_SET_VALUES_IOCTL)
+		return line_set_values(line, ip);
 	else if (cmd == GPIOLINE_SET_CONFIG_IOCTL)
 		return line_set_config(line, ip);
 
-- 
2.27.0