Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 945bd13..213aedc 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -18,6 +18,7 @@
 #include <linux/irq_sim.h>
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
+#include <linux/property.h>
 
 #include "gpiolib.h"
 
@@ -28,6 +29,8 @@
  * of GPIO lines.
  */
 #define GPIO_MOCKUP_MAX_RANGES	(GPIO_MOCKUP_MAX_GC * 2)
+/* Maximum of three properties + the sentinel. */
+#define GPIO_MOCKUP_MAX_PROP	4
 
 #define gpio_mockup_err(...)	pr_err(GPIO_MOCKUP_NAME ": " __VA_ARGS__)
 
@@ -44,6 +47,7 @@
 struct gpio_mockup_line_status {
 	int dir;
 	int value;
+	int pull;
 };
 
 struct gpio_mockup_chip {
@@ -51,19 +55,13 @@
 	struct gpio_mockup_line_status *lines;
 	struct irq_sim irqsim;
 	struct dentry *dbg_dir;
+	struct mutex lock;
 };
 
 struct gpio_mockup_dbgfs_private {
 	struct gpio_mockup_chip *chip;
 	struct gpio_desc *desc;
-	int offset;
-};
-
-struct gpio_mockup_platform_data {
-	int base;
-	int ngpio;
-	int index;
-	bool named_lines;
+	unsigned int offset;
 };
 
 static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_RANGES];
@@ -86,29 +84,66 @@
 	return gpio_mockup_ranges[index * 2 + 1];
 }
 
-static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
+static int __gpio_mockup_get(struct gpio_mockup_chip *chip,
+			     unsigned int offset)
 {
-	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
-
 	return chip->lines[offset].value;
 }
 
+static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
+{
+	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
+	int val;
+
+	mutex_lock(&chip->lock);
+	val = __gpio_mockup_get(chip, offset);
+	mutex_unlock(&chip->lock);
+
+	return val;
+}
+
+static int gpio_mockup_get_multiple(struct gpio_chip *gc,
+				    unsigned long *mask, unsigned long *bits)
+{
+	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
+	unsigned int bit, val;
+
+	mutex_lock(&chip->lock);
+	for_each_set_bit(bit, mask, gc->ngpio) {
+		val = __gpio_mockup_get(chip, bit);
+		__assign_bit(bit, bits, val);
+	}
+	mutex_unlock(&chip->lock);
+
+	return 0;
+}
+
+static void __gpio_mockup_set(struct gpio_mockup_chip *chip,
+			      unsigned int offset, int value)
+{
+	chip->lines[offset].value = !!value;
+}
+
 static void gpio_mockup_set(struct gpio_chip *gc,
-			    unsigned int offset, int value)
+			   unsigned int offset, int value)
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
 
-	chip->lines[offset].value = !!value;
+	mutex_lock(&chip->lock);
+	__gpio_mockup_set(chip, offset, value);
+	mutex_unlock(&chip->lock);
 }
 
 static void gpio_mockup_set_multiple(struct gpio_chip *gc,
 				     unsigned long *mask, unsigned long *bits)
 {
+	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
 	unsigned int bit;
 
+	mutex_lock(&chip->lock);
 	for_each_set_bit(bit, mask, gc->ngpio)
-		gpio_mockup_set(gc, bit, test_bit(bit, bits));
-
+		__gpio_mockup_set(chip, bit, test_bit(bit, bits));
+	mutex_unlock(&chip->lock);
 }
 
 static int gpio_mockup_dirout(struct gpio_chip *gc,
@@ -116,8 +151,10 @@
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
 
-	gpio_mockup_set(gc, offset, value);
+	mutex_lock(&chip->lock);
 	chip->lines[offset].dir = GPIO_MOCKUP_DIR_OUT;
+	__gpio_mockup_set(chip, offset, value);
+	mutex_unlock(&chip->lock);
 
 	return 0;
 }
@@ -126,7 +163,9 @@
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
 
+	mutex_lock(&chip->lock);
 	chip->lines[offset].dir = GPIO_MOCKUP_DIR_IN;
+	mutex_unlock(&chip->lock);
 
 	return 0;
 }
@@ -134,8 +173,13 @@
 static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
+	int direction;
 
-	return !chip->lines[offset].dir;
+	mutex_lock(&chip->lock);
+	direction = !chip->lines[offset].dir;
+	mutex_unlock(&chip->lock);
+
+	return direction;
 }
 
 static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset)
@@ -145,15 +189,52 @@
 	return irq_sim_irqnum(&chip->irqsim, offset);
 }
 
-static ssize_t gpio_mockup_event_write(struct file *file,
-				       const char __user *usr_buf,
-				       size_t size, loff_t *ppos)
+static void gpio_mockup_free(struct gpio_chip *gc, unsigned int offset)
+{
+	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
+
+	__gpio_mockup_set(chip, offset, chip->lines[offset].pull);
+}
+
+static ssize_t gpio_mockup_debugfs_read(struct file *file,
+					char __user *usr_buf,
+					size_t size, loff_t *ppos)
 {
 	struct gpio_mockup_dbgfs_private *priv;
 	struct gpio_mockup_chip *chip;
 	struct seq_file *sfile;
+	struct gpio_chip *gc;
+	int val, cnt;
+	char buf[3];
+
+	if (*ppos != 0)
+		return 0;
+
+	sfile = file->private_data;
+	priv = sfile->private;
+	chip = priv->chip;
+	gc = &chip->gc;
+
+	val = gpio_mockup_get(gc, priv->offset);
+	cnt = snprintf(buf, sizeof(buf), "%d\n", val);
+
+	return simple_read_from_buffer(usr_buf, size, ppos, buf, cnt);
+}
+
+static ssize_t gpio_mockup_debugfs_write(struct file *file,
+					 const char __user *usr_buf,
+					 size_t size, loff_t *ppos)
+{
+	struct gpio_mockup_dbgfs_private *priv;
+	int rv, val, curr, irq, irq_type;
+	struct gpio_mockup_chip *chip;
+	struct seq_file *sfile;
 	struct gpio_desc *desc;
-	int rv, val;
+	struct gpio_chip *gc;
+	struct irq_sim *sim;
+
+	if (*ppos != 0)
+		return -EINVAL;
 
 	rv = kstrtoint_from_user(usr_buf, size, 0, &val);
 	if (rv)
@@ -163,32 +244,78 @@
 
 	sfile = file->private_data;
 	priv = sfile->private;
-	desc = priv->desc;
 	chip = priv->chip;
+	gc = &chip->gc;
+	desc = &gc->gpiodev->descs[priv->offset];
+	sim = &chip->irqsim;
 
-	gpiod_set_value_cansleep(desc, val);
-	irq_sim_fire(&chip->irqsim, priv->offset);
+	mutex_lock(&chip->lock);
+
+	if (test_bit(FLAG_REQUESTED, &desc->flags) &&
+	    !test_bit(FLAG_IS_OUT, &desc->flags)) {
+		curr = __gpio_mockup_get(chip, priv->offset);
+		if (curr == val)
+			goto out;
+
+		irq = irq_sim_irqnum(sim, priv->offset);
+		irq_type = irq_get_trigger_type(irq);
+
+		if ((val == 1 && (irq_type & IRQ_TYPE_EDGE_RISING)) ||
+		    (val == 0 && (irq_type & IRQ_TYPE_EDGE_FALLING)))
+			irq_sim_fire(sim, priv->offset);
+	}
+
+	/* Change the value unless we're actively driving the line. */
+	if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
+	    !test_bit(FLAG_IS_OUT, &desc->flags))
+		__gpio_mockup_set(chip, priv->offset, val);
+
+out:
+	chip->lines[priv->offset].pull = val;
+	mutex_unlock(&chip->lock);
 
 	return size;
 }
 
-static int gpio_mockup_event_open(struct inode *inode, struct file *file)
+static int gpio_mockup_debugfs_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, NULL, inode->i_private);
 }
 
-static const struct file_operations gpio_mockup_event_ops = {
+/*
+ * Each mockup chip is represented by a directory named after the chip's device
+ * name under /sys/kernel/debug/gpio-mockup/. Each line is represented by
+ * a file using the line's offset as the name under the chip's directory.
+ *
+ * Reading from the line's file yields the current *value*, writing to the
+ * line's file changes the current *pull*. Default pull for mockup lines is
+ * down.
+ *
+ * Examples:
+ * - when a line pulled down is requested in output mode and driven high, its
+ *   value will return to 0 once it's released
+ * - when the line is requested in output mode and driven high, writing 0 to
+ *   the corresponding debugfs file will change the pull to down but the
+ *   reported value will still be 1 until the line is released
+ * - line requested in input mode always reports the same value as its pull
+ *   configuration
+ * - when the line is requested in input mode and monitored for events, writing
+ *   the same value to the debugfs file will be a noop, while writing the
+ *   opposite value will generate a dummy interrupt with an appropriate edge
+ */
+static const struct file_operations gpio_mockup_debugfs_ops = {
 	.owner = THIS_MODULE,
-	.open = gpio_mockup_event_open,
-	.write = gpio_mockup_event_write,
+	.open = gpio_mockup_debugfs_open,
+	.read = gpio_mockup_debugfs_read,
+	.write = gpio_mockup_debugfs_write,
 	.llseek = no_llseek,
+	.release = single_release,
 };
 
 static void gpio_mockup_debugfs_setup(struct device *dev,
 				      struct gpio_mockup_chip *chip)
 {
 	struct gpio_mockup_dbgfs_private *priv;
-	struct dentry *evfile, *link;
 	struct gpio_chip *gc;
 	const char *devname;
 	char *name;
@@ -198,36 +325,25 @@
 	devname = dev_name(&gc->gpiodev->dev);
 
 	chip->dbg_dir = debugfs_create_dir(devname, gpio_mockup_dbg_dir);
-	if (IS_ERR_OR_NULL(chip->dbg_dir))
-		goto err;
-
-	link = debugfs_create_symlink(gc->label, gpio_mockup_dbg_dir, devname);
-	if (IS_ERR_OR_NULL(link))
-		goto err;
 
 	for (i = 0; i < gc->ngpio; i++) {
 		name = devm_kasprintf(dev, GFP_KERNEL, "%d", i);
 		if (!name)
-			goto err;
+			return;
 
 		priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 		if (!priv)
-			goto err;
+			return;
 
 		priv->chip = chip;
 		priv->offset = i;
 		priv->desc = &gc->gpiodev->descs[i];
 
-		evfile = debugfs_create_file(name, 0200, chip->dbg_dir, priv,
-					     &gpio_mockup_event_ops);
-		if (IS_ERR_OR_NULL(evfile))
-			goto err;
+		debugfs_create_file(name, 0200, chip->dbg_dir, priv,
+				    &gpio_mockup_debugfs_ops);
 	}
 
 	return;
-
-err:
-	dev_err(dev, "error creating debugfs event files\n");
 }
 
 static int gpio_mockup_name_lines(struct device *dev,
@@ -255,26 +371,39 @@
 
 static int gpio_mockup_probe(struct platform_device *pdev)
 {
-	struct gpio_mockup_platform_data *pdata;
 	struct gpio_mockup_chip *chip;
 	struct gpio_chip *gc;
-	int rv, base, ngpio;
 	struct device *dev;
-	char *name;
+	const char *name;
+	int rv, base;
+	u16 ngpio;
 
 	dev = &pdev->dev;
-	pdata = dev_get_platdata(dev);
-	base = pdata->base;
-	ngpio = pdata->ngpio;
+
+	rv = device_property_read_u32(dev, "gpio-base", &base);
+	if (rv)
+		base = -1;
+
+	rv = device_property_read_u16(dev, "nr-gpios", &ngpio);
+	if (rv)
+		return rv;
+
+	rv = device_property_read_string(dev, "chip-name", &name);
+	if (rv)
+		name = NULL;
 
 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
 		return -ENOMEM;
 
-	name = devm_kasprintf(dev, GFP_KERNEL, "%s-%c",
-			      pdev->name, pdata->index);
-	if (!name)
-		return -ENOMEM;
+	if (!name) {
+		name = devm_kasprintf(dev, GFP_KERNEL,
+				      "%s-%c", pdev->name, pdev->id + 'A');
+		if (!name)
+			return -ENOMEM;
+	}
+
+	mutex_init(&chip->lock);
 
 	gc = &chip->gc;
 	gc->base = base;
@@ -284,18 +413,20 @@
 	gc->parent = dev;
 	gc->get = gpio_mockup_get;
 	gc->set = gpio_mockup_set;
+	gc->get_multiple = gpio_mockup_get_multiple;
 	gc->set_multiple = gpio_mockup_set_multiple;
 	gc->direction_output = gpio_mockup_dirout;
 	gc->direction_input = gpio_mockup_dirin;
 	gc->get_direction = gpio_mockup_get_direction;
 	gc->to_irq = gpio_mockup_to_irq;
+	gc->free = gpio_mockup_free;
 
 	chip->lines = devm_kcalloc(dev, gc->ngpio,
 				   sizeof(*chip->lines), GFP_KERNEL);
 	if (!chip->lines)
 		return -ENOMEM;
 
-	if (pdata->named_lines) {
+	if (device_property_read_bool(dev, "named-gpio-lines")) {
 		rv = gpio_mockup_name_lines(dev, chip);
 		if (rv)
 			return rv;
@@ -309,8 +440,7 @@
 	if (rv)
 		return rv;
 
-	if (!IS_ERR_OR_NULL(gpio_mockup_dbg_dir))
-		gpio_mockup_debugfs_setup(dev, chip);
+	gpio_mockup_debugfs_setup(dev, chip);
 
 	return 0;
 }
@@ -339,9 +469,11 @@
 
 static int __init gpio_mockup_init(void)
 {
-	int i, num_chips, err = 0, index = 'A';
-	struct gpio_mockup_platform_data pdata;
+	struct property_entry properties[GPIO_MOCKUP_MAX_PROP];
+	int i, prop, num_chips, err = 0, base;
+	struct platform_device_info pdevinfo;
 	struct platform_device *pdev;
+	u16 ngpio;
 
 	if ((gpio_mockup_num_ranges < 2) ||
 	    (gpio_mockup_num_ranges % 2) ||
@@ -360,9 +492,7 @@
 			return -EINVAL;
 	}
 
-	gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL);
-	if (IS_ERR_OR_NULL(gpio_mockup_dbg_dir))
-		gpio_mockup_err("error creating debugfs directory\n");
+	gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup", NULL);
 
 	err = platform_driver_register(&gpio_mockup_driver);
 	if (err) {
@@ -371,17 +501,28 @@
 	}
 
 	for (i = 0; i < num_chips; i++) {
-		pdata.index = index++;
-		pdata.base = gpio_mockup_range_base(i);
-		pdata.ngpio = pdata.base < 0
-				? gpio_mockup_range_ngpio(i)
-				: gpio_mockup_range_ngpio(i) - pdata.base;
-		pdata.named_lines = gpio_mockup_named_lines;
+		memset(properties, 0, sizeof(properties));
+		memset(&pdevinfo, 0, sizeof(pdevinfo));
+		prop = 0;
 
-		pdev = platform_device_register_resndata(NULL,
-							 GPIO_MOCKUP_NAME,
-							 i, NULL, 0, &pdata,
-							 sizeof(pdata));
+		base = gpio_mockup_range_base(i);
+		if (base >= 0)
+			properties[prop++] = PROPERTY_ENTRY_U32("gpio-base",
+								base);
+
+		ngpio = base < 0 ? gpio_mockup_range_ngpio(i)
+				 : gpio_mockup_range_ngpio(i) - base;
+		properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio);
+
+		if (gpio_mockup_named_lines)
+			properties[prop++] = PROPERTY_ENTRY_BOOL(
+						"named-gpio-lines");
+
+		pdevinfo.name = GPIO_MOCKUP_NAME;
+		pdevinfo.id = i;
+		pdevinfo.properties = properties;
+
+		pdev = platform_device_register_full(&pdevinfo);
 		if (IS_ERR(pdev)) {
 			gpio_mockup_err("error registering device");
 			platform_driver_unregister(&gpio_mockup_driver);