Re: [tpmdd-devel] [PATCH v7 05/10] tpm: device class for tpm

From: Stefan Berger
Date: Wed Nov 26 2014 - 07:34:24 EST


On 11/11/2014 08:45 AM, Jarkko Sakkinen wrote:
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@xxxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxxxx)");
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);

This looks ok to me.

Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>

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