btpower: Embeds cdev within driver data structure

In order to access driver data inside file ioctl calls, this CL embeds
the cdev within the driver data structure, and converts to the whole
driver data while file opening. The global driver data is no
longer used.

Bug: 202113218
Test: manually
Signed-off-by: Cheney Ni <cheneyni@google.com>
Change-Id: I45ebda47d04d44ed1ea02262a14f7723b33b675b

2 files changed, 90 insertions, 49 deletions

diff --git a/btpower.c b/btpower.c
index 0b36b9c..e5a30d4 100644
--- a/btpower.c
+++ b/btpower.c
@@ -207,11 +207,6 @@ static int bt_power_vreg_set(struct btpower_platform_data *drvdata,
 			     enum bt_power_modes mode);
 static int btpower_enable_ipa_vreg(struct btpower_platform_data *drvdata);
 
-static struct btpower_platform_data *bt_power_pdata;
-static struct class *bt_class;
-static int bt_major;
-static bool probe_finished;
-
 static int bt_vreg_enable(struct bt_power_vreg_data *vreg)
 {
 	int rc = 0;
@@ -689,6 +684,74 @@ static void btpower_rfkill_remove(struct platform_device *pdev)
 	rfkill_destroy(rfkill);
 }
 
+static int btpower_open(struct inode *inode, struct file *filp);
+static long btpower_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+static const struct file_operations bt_dev_fops = {
+	.owner = THIS_MODULE,
+	.open = btpower_open,
+	.unlocked_ioctl = btpower_ioctl,
+	.compat_ioctl = btpower_ioctl,
+};
+
+static int btpower_chardev_create(struct btpower_platform_data *drvdata)
+{
+	dev_t bpdevt;
+	struct class *bpcls;
+	struct device *bpdev;
+	int ret = 0;
+
+	ret = alloc_chrdev_region(&bpdevt, 0, 1, "bt");
+	if (ret || MAJOR(bpdevt) < 0) {
+		pr_err("%s: failed to register chardev number (%d)\n",
+			__func__, ret);
+		return ret;
+	}
+	cdev_init(&drvdata->cdev, &bt_dev_fops);
+	drvdata->cdev.owner = THIS_MODULE;
+	ret = cdev_add(&drvdata->cdev, bpdevt, 1);
+	if (ret) {
+		pr_err("%s: failed to add chardev (%d)\n", __func__, ret);
+                goto class_err;
+	}
+	pr_debug("%s: registered chardev number %d:%d\n", __func__,
+		MAJOR(drvdata->cdev.dev), MINOR(drvdata->cdev.dev));
+
+	bpcls = class_create(THIS_MODULE, "bt-dev");
+	if (IS_ERR_OR_NULL(bpcls)) {
+		ret = PTR_ERR(bpcls);
+		pr_err("%s: can't create class (%d)\n", __func__, ret);
+		goto class_err;
+	}
+
+	bpdev = device_create(bpcls, NULL, drvdata->cdev.dev,
+			drvdata, "btpower");
+	if (IS_ERR_OR_NULL(bpdev)) {
+		ret = PTR_ERR(bpdev);
+		pr_err("%s: failed to create device with sysfs (%d)\n",
+			__func__, ret);
+		goto device_err;
+	}
+	drvdata->cls = bpcls;
+	return 0;
+
+device_err:
+	class_destroy(bpcls);
+class_err:
+	unregister_chrdev(MAJOR(drvdata->cdev.dev), "bt");
+	return ret;
+}
+
+static void btpower_chardev_remove(struct btpower_platform_data *drvdata)
+{
+	if (!drvdata || !drvdata->cls)
+		return;
+
+	device_destroy(drvdata->cls, drvdata->cdev.dev);
+	class_destroy(drvdata->cls);
+	drvdata->cls = NULL;
+	unregister_chrdev(MAJOR(drvdata->cdev.dev), "bt");
+}
+
 static int bt_dt_parse_vreg_info(struct device *dev,
 				 struct bt_power_vreg_data *vreg)
 {
@@ -931,7 +994,6 @@ static int bt_power_probe(struct platform_device *pdev)
 	drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
 	if (!drvdata)
 		return -ENOMEM;
-	bt_power_pdata = drvdata;
 
 	drvdata->pdev = pdev;
 	/* Fill whole array with -2 i.e NOT_AVAILABLE state by default
@@ -965,10 +1027,16 @@ static int bt_power_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto free_pdata;
 
+	ret = btpower_chardev_create(drvdata);
+	if (ret) {
+		btpower_rfkill_remove(pdev);
+		goto free_pdata;
+	}
+
 	btpower_aop_mbox_init(drvdata);
 
 	platform_set_drvdata(pdev, drvdata);
-	probe_finished = true;
+
 	return 0;
 
 free_pdata:
@@ -985,7 +1053,7 @@ static int bt_power_remove(struct platform_device *pdev)
 	if (!drvdata)
 		return 0;
 
-	probe_finished = false;
+	btpower_chardev_remove(drvdata);
 	btpower_rfkill_remove(pdev);
 	bt_power_vreg_put(drvdata);
 
@@ -1051,15 +1119,22 @@ static void set_gpios_srcs_status(struct btpower_platform_data *drvdata,
 		drvdata->bt_power_src_status[gpio_index]);
 }
 
-static long bt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+static int btpower_open(struct inode *inode, struct file *filp)
+{
+	filp->private_data =
+		container_of(inode->i_cdev, struct btpower_platform_data, cdev);
+	return 0;
+}
+
+static long btpower_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
-	struct btpower_platform_data *drvdata = bt_power_pdata;
+	struct btpower_platform_data *drvdata = file->private_data;
 	int ret = 0, pwr_cntrl = 0;
 	int chipset_version = 0;
 	int itr, num_vregs;
 	const struct bt_power_vreg_data *vreg_info = NULL;
 
-	if (!drvdata || !probe_finished) {
+	if (!drvdata) {
 		pr_err("%s: device not ready\n", __func__);
 		return -ENODEV;
 	}
@@ -1164,51 +1239,14 @@ static struct platform_driver bt_power_driver = {
 	},
 };
 
-static const struct file_operations bt_dev_fops = {
-	.unlocked_ioctl = bt_ioctl,
-	.compat_ioctl = bt_ioctl,
-};
-
 static int __init btpower_init(void)
 {
 	int ret = 0;
 
-	probe_finished = false;
 	ret = platform_driver_register(&bt_power_driver);
-	if (ret) {
+	if (ret)
 		pr_err("%s: platform_driver_register error: %d\n",
 			__func__, ret);
-		goto driver_err;
-	}
-
-	bt_major = register_chrdev(0, "bt", &bt_dev_fops);
-	if (bt_major < 0) {
-		pr_err("%s: failed to allocate char dev\n", __func__);
-		ret = -1;
-		goto chrdev_err;
-	}
-
-	bt_class = class_create(THIS_MODULE, "bt-dev");
-	if (IS_ERR(bt_class)) {
-		pr_err("%s: coudn't create class\n", __func__);
-		ret = -1;
-		goto class_err;
-	}
-
-	if (device_create(bt_class, NULL, MKDEV(bt_major, 0),
-		NULL, "btpower") == NULL) {
-		pr_err("%s: failed to allocate char dev\n", __func__);
-		goto device_err;
-	}
-	return 0;
-
-device_err:
-	class_destroy(bt_class);
-class_err:
-	unregister_chrdev(bt_major, "bt");
-chrdev_err:
-	platform_driver_unregister(&bt_power_driver);
-driver_err:
 	return ret;
 }
 
diff --git a/linux/btpower.h b/linux/btpower.h
index c965a5a..22521ef 100644
--- a/linux/btpower.h
+++ b/linux/btpower.h
@@ -6,6 +6,7 @@
 #ifndef __LINUX_BLUETOOTH_POWER_H
 #define __LINUX_BLUETOOTH_POWER_H
 
+#include <linux/cdev.h>
 #include <linux/types.h>
 #include <linux/mailbox_client.h>
 #include <linux/mailbox/qmp.h>
@@ -58,6 +59,8 @@ struct bt_power_clk_data {
 struct btpower_platform_data {
 	struct platform_device *pdev;
 	struct rfkill *rfkill;
+	struct cdev cdev;
+	struct class *cls;
 	struct device *slim_dev;
 
 	int chipset_version;