[PATCH v2 2/2] mfd: ucb1x00: Convert Assabet gpio-keys to use software nodes

[Dmitry Torokhov]

Convert the legacy gpio-keys platform device on the StrongARM SA-1100
Assabet evaluation board to use software nodes and device properties.
This allows describing the buttons and their GPIO bindings via software
nodes so that platform data support can eventually be removed from the
gpio-keys driver.

Define static software nodes for the gpio-keys device and the six button
child nodes at file scope using relative pin indexing on the UCB1x00 GPIO
controller node. In ucb1x00_assabet_add(), register the software node
group and use platform_device_register_full() to register the device.

Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
 drivers/mfd/ucb1x00-assabet.c | 124 +++++++++++++++++++++++++++++++++---------
 1 file changed, 98 insertions(+), 26 deletions(-)

diff --git a/drivers/mfd/ucb1x00-assabet.c b/drivers/mfd/ucb1x00-assabet.c
index 6a389737c615..ee49ac779d1a 100644
--- a/drivers/mfd/ucb1x00-assabet.c
+++ b/drivers/mfd/ucb1x00-assabet.c
@@ -6,15 +6,18 @@
  *
  *  We handle the machine-specific bits of the UCB1x00 driver here.
  */
-#include <linux/module.h>
-#include <linux/init.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/fs.h>
-#include <linux/gpio_keys.h>
+#include <linux/gpio/machine.h>
+#include <linux/gpio/property.h>
+#include <linux/init.h>
 #include <linux/input.h>
+#include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/proc_fs.h>
+#include <linux/property.h>
+#include <linux/slab.h>
 #include <linux/mfd/ucb1x00.h>
 
 #define UCB1X00_ATTR(name,input)\
@@ -34,50 +37,119 @@ UCB1X00_ATTR(vbatt, UCB_ADC_INP_AD1);
 UCB1X00_ATTR(vcharger, UCB_ADC_INP_AD0);
 UCB1X00_ATTR(batt_temp, UCB_ADC_INP_AD2);
 
+static const struct property_entry ucb1x00_gpio_keys_props[] = {
+	PROPERTY_ENTRY_STRING("label", "ucb1x00"),
+	PROPERTY_ENTRY_U32("poll-interval", 50),
+	{ }
+};
+
+#define UCB1X00_BTN_PROPS(_idx)						\
+struct property_entry ucb1x00_btn##_idx##_props[] = {			\
+	PROPERTY_ENTRY_U32("linux,code", BTN_0 + (_idx)),		\
+	PROPERTY_ENTRY_GPIO("gpios", &ucb1x00_gpiochip_node,		\
+			    _idx, GPIO_ACTIVE_HIGH),			\
+	PROPERTY_ENTRY_STRING("label", "btn" #_idx),			\
+	PROPERTY_ENTRY_BOOL("linux,can-disable"),			\
+	{ }								\
+}
+
+static const UCB1X00_BTN_PROPS(0);
+static const UCB1X00_BTN_PROPS(1);
+static const UCB1X00_BTN_PROPS(2);
+static const UCB1X00_BTN_PROPS(3);
+static const UCB1X00_BTN_PROPS(4);
+static const UCB1X00_BTN_PROPS(5);
+
+static const struct property_entry * const ucb1x00_btn_props[] = {
+	ucb1x00_btn0_props,
+	ucb1x00_btn1_props,
+	ucb1x00_btn2_props,
+	ucb1x00_btn3_props,
+	ucb1x00_btn4_props,
+	ucb1x00_btn5_props,
+};
+
+struct ucb1x00_assabet_priv {
+	struct platform_device *pdev;
+	struct fwnode_handle *keys_node;
+	struct fwnode_handle *button_nodes[ARRAY_SIZE(ucb1x00_btn_props)];
+};
+
+static void ucb1x00_assabet_remove_nodes(struct ucb1x00_assabet_priv *priv, int n)
+{
+	while (--n >= 0)
+		fwnode_remove_software_node(priv->button_nodes[n]);
+
+	fwnode_remove_software_node(priv->keys_node);
+}
+
 static int ucb1x00_assabet_add(struct ucb1x00_dev *dev)
 {
 	struct ucb1x00 *ucb = dev->ucb;
-	struct platform_device *pdev;
-	struct gpio_keys_platform_data keys;
-	static struct gpio_keys_button buttons[6];
-	unsigned i;
-
-	memset(buttons, 0, sizeof(buttons));
-	memset(&keys, 0, sizeof(keys));
-
-	for (i = 0; i < ARRAY_SIZE(buttons); i++) {
-		buttons[i].code = BTN_0 + i;
-		buttons[i].gpio = ucb->gpio.base + i;
-		buttons[i].type = EV_KEY;
-		buttons[i].can_disable = true;
+	struct platform_device_info pdevinfo = {
+		.name = "gpio-keys",
+		.id = PLATFORM_DEVID_NONE,
+		.parent = &ucb->dev,
+	};
+	int ret;
+	int i;
+
+	struct ucb1x00_assabet_priv *priv;
+
+	priv = kzalloc_obj(*priv, GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->keys_node = fwnode_create_software_node(ucb1x00_gpio_keys_props, NULL);
+	if (IS_ERR(priv->keys_node)) {
+		ret = PTR_ERR(priv->keys_node);
+		goto err_free_priv;
 	}
 
-	keys.buttons = buttons;
-	keys.nbuttons = ARRAY_SIZE(buttons);
-	keys.poll_interval = 50;
-	keys.name = "ucb1x00";
+	for (i = 0; i < ARRAY_SIZE(ucb1x00_btn_props); i++) {
+		priv->button_nodes[i] = fwnode_create_software_node(ucb1x00_btn_props[i],
+								    priv->keys_node);
+		if (IS_ERR(priv->button_nodes[i])) {
+			ret = PTR_ERR(priv->button_nodes[i]);
+			goto err_free_buttons;
+		}
+	}
+
+	pdevinfo.fwnode = priv->keys_node;
 
-	pdev = platform_device_register_data(&ucb->dev, "gpio-keys", -1,
-		&keys, sizeof(keys));
+	priv->pdev = platform_device_register_full(&pdevinfo);
+	ret = PTR_ERR_OR_ZERO(priv->pdev);
+	if (ret)
+		goto err_free_buttons;
 
 	device_create_file(&ucb->dev, &dev_attr_vbatt);
 	device_create_file(&ucb->dev, &dev_attr_vcharger);
 	device_create_file(&ucb->dev, &dev_attr_batt_temp);
 
-	dev->priv = pdev;
+	dev->priv = priv;
 	return 0;
+
+err_free_buttons:
+	ucb1x00_assabet_remove_nodes(priv, i);
+err_free_priv:
+	kfree(priv);
+	return ret;
 }
 
 static void ucb1x00_assabet_remove(struct ucb1x00_dev *dev)
 {
-	struct platform_device *pdev = dev->priv;
+	struct ucb1x00_assabet_priv *priv = dev->priv;
 
-	if (!IS_ERR(pdev))
-		platform_device_unregister(pdev);
+	if (!IS_ERR(priv->pdev))
+		platform_device_unregister(priv->pdev);
+
+	ucb1x00_assabet_remove_nodes(priv, ARRAY_SIZE(priv->button_nodes));
 
 	device_remove_file(&dev->ucb->dev, &dev_attr_batt_temp);
 	device_remove_file(&dev->ucb->dev, &dev_attr_vcharger);
 	device_remove_file(&dev->ucb->dev, &dev_attr_vbatt);
+
+	kfree(priv);
 }
 
 static struct ucb1x00_driver ucb1x00_assabet_driver = {

-- 
2.55.0.rc2.803.g1fd1e6609c-goog