[PATCH v2 05/10] gpio: aggregator: expose custom line names to forwarder gpio_chip

[Koichiro Den]

Previously, GPIO lines in the aggregator had empty names. Now that the
configfs interface supports custom names, update the GPIO forwarder to
use them.

Signed-off-by: Koichiro Den <koichiro.den@xxxxxxxxxxxxx>
---
 drivers/gpio/gpio-aggregator.c | 71 ++++++++++++++++++++++++++++++++--
 1 file changed, 68 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index 3263d99bfe69..268b9b580ada 100644
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -425,6 +425,20 @@ static int gpiochip_fwd_setup_delay_line(struct device *dev, struct gpio_chip *c
 }
 #endif	/* !CONFIG_OF_GPIO */
 
+static int gpiochip_fwd_line_names(struct device *dev, const char **names, int len)
+{
+	int num = device_property_string_array_count(dev, "gpio-line-names");
+	if (!num)
+		return 0;
+	if (num > len) {
+		pr_warn("gpio-line-names contains %d lines while %d expected",
+			num, len);
+		num = len;
+	}
+	return device_property_read_string_array(dev, "gpio-line-names",
+						 names, num);
+}
+
 /**
  * gpiochip_fwd_create() - Create a new GPIO forwarder
  * @dev: Parent device pointer
@@ -447,6 +461,7 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
 {
 	const char *label = dev_name(dev);
 	struct gpiochip_fwd *fwd;
+	const char **line_names;
 	struct gpio_chip *chip;
 	unsigned int i;
 	int error;
@@ -458,6 +473,16 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
 
 	chip = &fwd->chip;
 
+	if (!dev_of_node(dev)) {
+		line_names = devm_kcalloc(dev, sizeof(*line_names), ngpios, GFP_KERNEL);
+		if (!line_names)
+			return ERR_PTR(-ENOMEM);
+
+		error = gpiochip_fwd_line_names(dev, line_names, ngpios);
+		if (error < 0)
+			return ERR_PTR(-ENOMEM);
+	}
+
 	/*
 	 * If any of the GPIO lines are sleeping, then the entire forwarder
 	 * will be sleeping.
@@ -491,6 +516,9 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
 	chip->ngpio = ngpios;
 	fwd->descs = descs;
 
+	if (!dev_of_node(dev))
+		chip->names = line_names;
+
 	if (chip->can_sleep)
 		mutex_init(&fwd->mlock);
 	else
@@ -530,10 +558,40 @@ to_gpio_aggregator_line(struct config_item *item)
 	return container_of(group, struct gpio_aggregator_line, group);
 }
 
+static struct fwnode_handle *aggr_make_device_swnode(struct gpio_aggregator *aggr)
+{
+	char **line_names __free(kfree) = NULL;
+	struct property_entry properties[2];
+	struct gpio_aggregator_line *line;
+	size_t num_lines;
+	int n = 0;
+
+	memset(properties, 0, sizeof(properties));
+
+	num_lines = aggr_count_lines(aggr);
+	if (num_lines == 0)
+		return NULL;
+
+	line_names = kcalloc(num_lines, sizeof(*line_names), GFP_KERNEL);
+	if (!line_names)
+		return ERR_PTR(-ENOMEM);
+
+	/* The list is always sorted as new elements are inserted in order. */
+	list_for_each_entry(line, &aggr->list_head, entry)
+		line_names[n++] = line->name ?: "";
+
+	properties[0] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
+					"gpio-line-names",
+					line_names, num_lines);
+
+	return fwnode_create_software_node(properties, NULL);
+}
+
 static int aggr_activate(struct gpio_aggregator *aggr)
 {
 	struct platform_device_info pdevinfo;
 	struct gpio_aggregator_line *line;
+	struct fwnode_handle *swnode;
 	struct platform_device *pdev;
 	unsigned int n = 0;
 	int ret = 0;
@@ -546,9 +604,14 @@ static int aggr_activate(struct gpio_aggregator *aggr)
 	if (!aggr->lookups)
 		return -ENOMEM;
 
+	swnode = aggr_make_device_swnode(aggr);
+	if (IS_ERR(swnode))
+		goto err_remove_lookups;
+
 	memset(&pdevinfo, 0, sizeof(pdevinfo));
 	pdevinfo.name = DRV_NAME;
 	pdevinfo.id = aggr->id;
+	pdevinfo.fwnode = swnode;
 
 	/* The list is always sorted as new elements are inserted in order. */
 	list_for_each_entry(line, &aggr->list_head, entry) {
@@ -560,7 +623,7 @@ static int aggr_activate(struct gpio_aggregator *aggr)
 		 */
 		if (!line->key || line->idx != n) {
 			ret = -EINVAL;
-			goto err_remove_lookups;
+			goto err_remove_swnode;
 		}
 
 		if (line->offset < 0)
@@ -568,13 +631,13 @@ static int aggr_activate(struct gpio_aggregator *aggr)
 		else
 			ret = aggr_add_gpio(aggr, line->key, line->offset, &n);
 		if (ret)
-			goto err_remove_lookups;
+			goto err_remove_swnode;
 	}
 
 	aggr->lookups->dev_id = kasprintf(GFP_KERNEL, "%s.%d", DRV_NAME, aggr->id);
 	if (!aggr->lookups->dev_id) {
 		ret = -ENOMEM;
-		goto err_remove_lookups;
+		goto err_remove_swnode;
 	}
 
 	gpiod_add_lookup_table(aggr->lookups);
@@ -607,6 +670,8 @@ static int aggr_activate(struct gpio_aggregator *aggr)
 err_remove_lookup_table:
 	kfree(aggr->lookups->dev_id);
 	gpiod_remove_lookup_table(aggr->lookups);
+err_remove_swnode:
+	fwnode_remove_software_node(swnode);
 err_remove_lookups:
 	kfree(aggr->lookups);
 
-- 
2.45.2