Re: [PATCH 1/1] [Blackfin] char driver for Blackfin on-chip OTP memory

From: Jiri Slaby
Date: Wed Jan 30 2008 - 06:00:27 EST


On 01/30/2008 11:36 AM, Bryan Wu wrote:
From: Mike Frysinger <michael.frysinger@xxxxxxxxxx>

initial char driver for otp memory
(only read supported atm ... needs real examples/docs for write support)

Signed-off-by: Mike Frysinger <michael.frysinger@xxxxxxxxxx>
Signed-off-by: Bryan Wu <bryan.wu@xxxxxxxxxx>
---
drivers/char/Kconfig | 28 +++++++
drivers/char/Makefile | 1 +
drivers/char/bfin-otp.c | 203 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 232 insertions(+), 0 deletions(-)
create mode 100644 drivers/char/bfin-otp.c

[...]
diff --git a/drivers/char/bfin-otp.c b/drivers/char/bfin-otp.c
new file mode 100644
index 0000000..896a987
--- /dev/null
+++ b/drivers/char/bfin-otp.c
@@ -0,0 +1,203 @@
+/*
+ * Blackfin On-Chip OTP Memory Interface
+ * Supports BF52x/BF54x
+ *
+ * Copyright 2007-2008 Analog Devices Inc.
+ *
+ * Enter bugs at http://blackfin.uclinux.org/
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/types.h>
+
+#include <asm/blackfin.h>
+#include <asm/uaccess.h>
+
+#define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
+#define stampit() stamp("here i am")
+
+#define DRIVER_NAME "bfin-otp"
+#define PFX DRIVER_NAME ": "
+
+DEFINE_MUTEX(bfin_otp_lock);

static?

+
+/* OTP Boot ROM functions */
+#define _BOOTROM_OTP_COMMAND 0xEF000018
+#define _BOOTROM_OTP_READ 0xEF00001A
+#define _BOOTROM_OTP_WRITE 0xEF00001C
[...]
+/**
+ * bfin_otp_init - Initialize module
+ *
+ * Registers the device and notifier handler. Actual device
+ * initialization is handled by bfin_otp_open().
+ */
+static int __init bfin_otp_init(void)
+{
+ int ret;
+
+ stampit();
+
+ ret = alloc_chrdev_region(&bfin_otp_dev_node, 0, 1, "otp");
+ if (ret) {
+ printk(KERN_ERR PFX "unable to get a char device\n");
+ return ret;
+ }
+
+ cdev_init(&bfin_otp_cdev, &bfin_otp_fops);
+ bfin_otp_cdev.owner = THIS_MODULE;
+ bfin_otp_cdev.ops = &bfin_otp_fops;

You don't need to set the fops again.

+
+ ret = cdev_add(&bfin_otp_cdev, bfin_otp_dev_node, 1);
+ if (ret) {
+ unregister_chrdev_region(bfin_otp_dev_node, 1);
+ printk(KERN_ERR PFX "unable to register char device\n");
+ return ret;
+ }
+
+ bfin_otp_class = class_create(THIS_MODULE, "otp");
+ device_create(bfin_otp_class, NULL, bfin_otp_dev_node, "otp");

Anyway, wouldn't be easier/better to use misc.c functionality here (misc_register() et al.)?

+
+ printk(KERN_INFO PFX "initialized\n");
+
+ return 0;
+}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/