[PATCH v7 05/10] tpm: device class for tpm

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

Added own device class for TPM. Uses MISC_MAJOR:TPM_MINOR for the
first character device in order to retain backwards compatability.
Added tpm_dev_release() back attached to the character device.
devm now only calls put_device when the platform device is removed.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 drivers/char/tpm/tpm-chip.c        | 81 ++++++++++++++++++++++++++++++++++----
 drivers/char/tpm/tpm-dev.c         | 36 ++---------------
 drivers/char/tpm/tpm-interface.c   | 29 ++++++++++++++
 drivers/char/tpm/tpm.h             | 12 ++++--
 drivers/char/tpm/tpm_i2c_nuvoton.c |  2 +-
 drivers/char/tpm/tpm_tis.c         |  4 +-
 6 files changed, 116 insertions(+), 48 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 96ea8eb..df40eee 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -25,6 +25,7 @@
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
 #include <linux/freezer.h>
+#include <linux/major.h>
 #include "tpm.h"
 #include "tpm_eventlog.h"
 
@@ -32,6 +33,9 @@ static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
 static LIST_HEAD(tpm_chip_list);
 static DEFINE_SPINLOCK(driver_lock);
 
+struct class *tpm_class;
+dev_t tpm_devt;
+
 /*
  * tpm_chip_find_get - return tpm_chip for a given chip number
  * @chip_num the device number for the chip
@@ -55,16 +59,24 @@ struct tpm_chip *tpm_chip_find_get(int chip_num)
 }
 
 /**
- * tpmm_chip_remove() - free chip memory and device number
- * @data: points to struct tpm_chip instance
+ * tpmm_put_device() - wrap put_device() for devm
+ * @data: points to the device
+ */
+static void tpmm_put_device(void *data)
+{
+	struct device *dev = (struct device *) data;
+	put_device(dev);
+}
+
+/**
+ * tpm_dev_release() - free chip memory and the device number
+ * @dev: the character device for the TPM chip
  *
- * This is used internally by tpmm_chip_alloc() and called by devres
- * when the device is released. This function does the opposite of
- * tpmm_chip_alloc() freeing memory and the device number.
+ * This is used as the release function for the character device.
  */
-static void tpmm_chip_remove(void *data)
+static void tpm_dev_release(struct device *dev)
 {
-	struct tpm_chip *chip = (struct tpm_chip *) data;
+	struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
 
 	spin_lock(&driver_lock);
 	clear_bit(chip->dev_num, dev_mask);
@@ -112,13 +124,66 @@ struct tpm_chip *tpmm_chip_alloc(struct device *dev,
 		  chip->dev_num);
 
 	chip->pdev = dev;
-	devm_add_action(dev, tpmm_chip_remove, chip);
+
 	dev_set_drvdata(dev, chip);
 
+	chip->dev.class = tpm_class;
+	chip->dev.release = tpm_dev_release;
+	chip->dev.parent = chip->pdev;
+
+	if (chip->dev_num == 0)
+		chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR);
+	else
+		chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num);
+
+	dev_set_name(&chip->dev, chip->devname);
+
+	device_initialize(&chip->dev);
+
+	chip->cdev.owner = chip->pdev->driver->owner;
+	cdev_init(&chip->cdev, &tpm_fops);
+
+	devm_add_action(dev, tpmm_put_device, chip);
 	return chip;
 }
 EXPORT_SYMBOL_GPL(tpmm_chip_alloc);
 
+static int tpm_dev_add_device(struct tpm_chip *chip)
+{
+	int rc;
+
+	rc = device_add(&chip->dev);
+	if (rc) {
+		dev_err(&chip->dev,
+			"unable to device_register %s, major %d, minor %d " \
+			"err=%d\n",
+			chip->devname, MAJOR(chip->dev.devt),
+			MINOR(chip->dev.devt), rc);
+
+		return rc;
+	}
+
+	rc = cdev_add(&chip->cdev, chip->dev.devt, 1);
+	if (rc) {
+		dev_err(&chip->dev,
+			"unable to cdev_add %s, major %d, minor %d " \
+			"err=%d\n",
+			chip->devname, MAJOR(chip->dev.devt),
+			MINOR(chip->dev.devt), rc);
+
+		device_unregister(&chip->dev);
+		return rc;
+	}
+
+	return rc;
+}
+
+static void tpm_dev_del_device(struct tpm_chip *chip)
+{
+	cdev_del(&chip->cdev);
+	device_unregister(&chip->dev);
+}
+
 /*
  * tpm_chip_register() - create a misc driver for the TPM chip
  * @chip: TPM chip to use.
diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c
index 3568321..de0337e 100644
--- a/drivers/char/tpm/tpm-dev.c
+++ b/drivers/char/tpm/tpm-dev.c
@@ -17,7 +17,6 @@
  * License.
  *
  */
-#include <linux/miscdevice.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #include "tpm.h"
@@ -54,9 +53,8 @@ static void timeout_work(struct work_struct *work)
 
 static int tpm_open(struct inode *inode, struct file *file)
 {
-	struct miscdevice *misc = file->private_data;
-	struct tpm_chip *chip = container_of(misc, struct tpm_chip,
-					     vendor.miscdev);
+	struct tpm_chip *chip =
+		container_of(inode->i_cdev, struct tpm_chip, cdev);
 	struct file_priv *priv;
 
 	/* It's assured that the chip will be opened just once,
@@ -173,7 +171,7 @@ static int tpm_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
-static const struct file_operations tpm_fops = {
+const struct file_operations tpm_fops = {
 	.owner = THIS_MODULE,
 	.llseek = no_llseek,
 	.open = tpm_open,
@@ -182,32 +180,4 @@ static const struct file_operations tpm_fops = {
 	.release = tpm_release,
 };
 
-int tpm_dev_add_device(struct tpm_chip *chip)
-{
-	int rc;
 
-	chip->vendor.miscdev.fops = &tpm_fops;
-	if (chip->dev_num == 0)
-		chip->vendor.miscdev.minor = TPM_MINOR;
-	else
-		chip->vendor.miscdev.minor = MISC_DYNAMIC_MINOR;
-
-	chip->vendor.miscdev.name = chip->devname;
-	chip->vendor.miscdev.parent = chip->pdev;
-
-	rc = misc_register(&chip->vendor.miscdev);
-	if (rc) {
-		chip->vendor.miscdev.name = NULL;
-		dev_err(chip->pdev,
-			"unable to misc_register %s, minor %d err=%d\n",
-			chip->vendor.miscdev.name,
-			chip->vendor.miscdev.minor, rc);
-	}
-	return rc;
-}
-
-void tpm_dev_del_device(struct tpm_chip *chip)
-{
-	if (chip->vendor.miscdev.name)
-		misc_deregister(&chip->vendor.miscdev);
-}
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index e6b08bd..9e4ce4d 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -997,6 +997,35 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
 }
 EXPORT_SYMBOL_GPL(tpm_get_random);
 
+static int __init tpm_init(void)
+{
+	int rc;
+
+	tpm_class = class_create(THIS_MODULE, "tpm");
+	if (IS_ERR(tpm_class)) {
+		pr_err("couldn't create tpm class\n");
+		return PTR_ERR(tpm_class);
+	}
+
+	rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
+	if (rc < 0) {
+		pr_err("tpm: failed to allocate char dev region\n");
+		class_destroy(tpm_class);
+		return rc;
+	}
+
+	return 0;
+}
+
+static void __exit tpm_exit(void)
+{
+	class_destroy(tpm_class);
+	unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
+}
+
+subsys_initcall(tpm_init);
+module_exit(tpm_exit);
+
 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 MODULE_DESCRIPTION("TPM Driver");
 MODULE_VERSION("2.0");
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index b3a7c76..83103e0 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -23,11 +23,11 @@
 #include <linux/fs.h>
 #include <linux/mutex.h>
 #include <linux/sched.h>
-#include <linux/miscdevice.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/tpm.h>
 #include <linux/acpi.h>
+#include <linux/cdev.h>
 
 enum tpm_const {
 	TPM_MINOR = 224,	/* officially assigned */
@@ -74,7 +74,6 @@ struct tpm_vendor_specific {
 	int region_size;
 	int have_region;
 
-	struct miscdevice miscdev;
 	struct list_head list;
 	int locality;
 	unsigned long timeout_a, timeout_b, timeout_c, timeout_d; /* jiffies */
@@ -99,6 +98,9 @@ struct tpm_vendor_specific {
 
 struct tpm_chip {
 	struct device *pdev;	/* Device stuff */
+	struct device dev;
+	struct cdev cdev;
+
 	const struct tpm_class_ops *ops;
 
 	int dev_num;		/* /dev/tpm# */
@@ -320,6 +322,10 @@ struct tpm_cmd_t {
 	tpm_cmd_params	params;
 } __packed;
 
+extern struct class *tpm_class;
+extern dev_t tpm_devt;
+extern const struct file_operations tpm_fops;
+
 ssize_t	tpm_getcap(struct device *, __be32, cap_t *, const char *);
 ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 		     size_t bufsiz);
@@ -340,8 +346,6 @@ extern struct tpm_chip *tpmm_chip_alloc(struct device *dev,
 extern int tpm_chip_register(struct tpm_chip *chip);
 extern void tpm_chip_unregister(struct tpm_chip *chip);
 
-int tpm_dev_add_device(struct tpm_chip *chip);
-void tpm_dev_del_device(struct tpm_chip *chip);
 int tpm_sysfs_add_device(struct tpm_chip *chip);
 void tpm_sysfs_del_device(struct tpm_chip *chip);
 
diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
index 92ee9fa..14246e2 100644
--- a/drivers/char/tpm/tpm_i2c_nuvoton.c
+++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
@@ -557,7 +557,7 @@ static int i2c_nuvoton_probe(struct i2c_client *client,
 		rc = devm_request_irq(dev, chip->vendor.irq,
 				      i2c_nuvoton_int_handler,
 				      IRQF_TRIGGER_LOW,
-				      chip->vendor.miscdev.name,
+				      chip->devname,
 				      chip);
 		if (rc) {
 			dev_err(dev, "%s() Unable to request irq: %d for use\n",
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index 660d9af..7a2c59b 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -661,7 +661,7 @@ static int tpm_tis_init(struct device *dev, acpi_handle acpi_dev_handle,
 				 TPM_INT_VECTOR(chip->vendor.locality));
 			if (devm_request_irq
 			    (dev, i, tis_int_probe, IRQF_SHARED,
-			     chip->vendor.miscdev.name, chip) != 0) {
+			     chip->devname, chip) != 0) {
 				dev_info(chip->pdev,
 					 "Unable to request irq: %d for probe\n",
 					 i);
@@ -708,7 +708,7 @@ static int tpm_tis_init(struct device *dev, acpi_handle acpi_dev_handle,
 			 TPM_INT_VECTOR(chip->vendor.locality));
 		if (devm_request_irq
 		    (dev, chip->vendor.irq, tis_int_handler, IRQF_SHARED,
-		     chip->vendor.miscdev.name, chip) != 0) {
+		     chip->devname, chip) != 0) {
 			dev_info(chip->pdev,
 				 "Unable to request irq: %d for use\n",
 				 chip->vendor.irq);
-- 
2.1.0