Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9eab0a78 authored by Austin Boyle's avatar Austin Boyle Committed by Linus Torvalds
Browse files

rtc: ds1307: generalise ram size and offset 



Generalise NVRAM to support RAM with other size and offset, such as the
64 bytes of SRAM on the mcp7941x.

[rdunlap@xenotime.net: fix printk format warning]
Signed-off-by: default avatarAustin Boyle <Austin.Boyle@aviatnet.com>
Signed-off-by: default avatarWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: default avatarRandy Dunlap <rdunlap@xenotime.net>
Cc: David Anders <danders.dev@gmail.com>
Cc: Alessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 40ce972d

drivers/rtc/rtc-ds1307.c

+47 −31
Original line number Diff line number Diff line
@@ -105,6 +105,8 @@ enum ds_type { 
struct ds1307 {

	u8			offset; /* register's offset */

	u8			regs[11];

	u16			nvram_offset;

	struct bin_attribute	*nvram;

	enum ds_type		type;

	unsigned long		flags;

#define HAS_NVRAM	0		/* bit 0 == sysfs file active */
@@ -119,19 +121,22 @@ struct ds1307 { 
};



struct chip_desc {

	unsigned		nvram56:1;

	unsigned		alarm:1;

	u16			nvram_offset;

	u16			nvram_size;

};



static const struct chip_desc chips[last_ds_type] = {

	[ds_1307] = {

		.nvram56	= 1,

		.nvram_offset	= 8,

		.nvram_size	= 56,

	},

	[ds_1337] = {

		.alarm		= 1,

	},

	[ds_1338] = {

		.nvram56	= 1,

		.nvram_offset	= 8,

		.nvram_size	= 56,

	},

	[ds_1339] = {

		.alarm		= 1,
@@ -139,6 +144,11 @@ static const struct chip_desc chips[last_ds_type] = { 
	[ds_3231] = {

		.alarm		= 1,

	},

	[mcp7941x] = {

		/* this is battery backed SRAM */

		.nvram_offset	= 0x20,

		.nvram_size	= 0x40,

	},

};



static const struct i2c_device_id ds1307_id[] = {
@@ -543,8 +553,6 @@ static const struct rtc_class_ops ds13xx_rtc_ops = { 


/*----------------------------------------------------------------------*/



#define NVRAM_SIZE	56



static ssize_t

ds1307_nvram_read(struct file *filp, struct kobject *kobj,

		struct bin_attribute *attr,
@@ -557,14 +565,15 @@ ds1307_nvram_read(struct file *filp, struct kobject *kobj, 
	client = kobj_to_i2c_client(kobj);

	ds1307 = i2c_get_clientdata(client);



	if (unlikely(off >= NVRAM_SIZE))

	if (unlikely(off >= ds1307->nvram->size))

		return 0;

	if ((off + count) > NVRAM_SIZE)

		count = NVRAM_SIZE - off;

	if ((off + count) > ds1307->nvram->size)

		count = ds1307->nvram->size - off;

	if (unlikely(!count))

		return count;



	result = ds1307->read_block_data(client, 8 + off, count, buf);

	result = ds1307->read_block_data(client, ds1307->nvram_offset + off,

								count, buf);

	if (result < 0)

		dev_err(&client->dev, "%s error %d\n", "nvram read", result);

	return result;
@@ -582,14 +591,15 @@ ds1307_nvram_write(struct file *filp, struct kobject *kobj, 
	client = kobj_to_i2c_client(kobj);

	ds1307 = i2c_get_clientdata(client);



	if (unlikely(off >= NVRAM_SIZE))

	if (unlikely(off >= ds1307->nvram->size))

		return -EFBIG;

	if ((off + count) > NVRAM_SIZE)

		count = NVRAM_SIZE - off;

	if ((off + count) > ds1307->nvram->size)

		count = ds1307->nvram->size - off;

	if (unlikely(!count))

		return count;



	result = ds1307->write_block_data(client, 8 + off, count, buf);

	result = ds1307->write_block_data(client, ds1307->nvram_offset + off,

								count, buf);

	if (result < 0) {

		dev_err(&client->dev, "%s error %d\n", "nvram write", result);

		return result;
@@ -597,17 +607,6 @@ ds1307_nvram_write(struct file *filp, struct kobject *kobj, 
	return count;

}



static struct bin_attribute nvram = {

	.attr = {

		.name	= "nvram",

		.mode	= S_IRUGO | S_IWUSR,

	},



	.read	= ds1307_nvram_read,

	.write	= ds1307_nvram_write,

	.size	= NVRAM_SIZE,

};



/*----------------------------------------------------------------------*/



static int __devinit ds1307_probe(struct i2c_client *client,
@@ -894,16 +893,31 @@ static int __devinit ds1307_probe(struct i2c_client *client, 
		dev_dbg(&client->dev, "got IRQ %d\n", client->irq);

	}



	if (chip->nvram56) {

		err = sysfs_create_bin_file(&client->dev.kobj, &nvram);

		if (err == 0) {

			set_bit(HAS_NVRAM, &ds1307->flags);

			dev_info(&client->dev, "56 bytes nvram\n");

	if (chip->nvram_size) {

		ds1307->nvram = kzalloc(sizeof(struct bin_attribute),

							GFP_KERNEL);

		if (!ds1307->nvram) {

			err = -ENOMEM;

			goto exit_nvram;

		}

		ds1307->nvram->attr.name = "nvram";

		ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;

		ds1307->nvram->read = ds1307_nvram_read,

		ds1307->nvram->write = ds1307_nvram_write,

		ds1307->nvram->size = chip->nvram_size;

		ds1307->nvram_offset = chip->nvram_offset;

		err = sysfs_create_bin_file(&client->dev.kobj, ds1307->nvram);

		if (err) {

			kfree(ds1307->nvram);

			goto exit_nvram;

		}

		set_bit(HAS_NVRAM, &ds1307->flags);

		dev_info(&client->dev, "%zu bytes nvram\n", ds1307->nvram->size);

	}



	return 0;



exit_nvram:

exit_irq:

	rtc_device_unregister(ds1307->rtc);

exit_free:
@@ -920,8 +934,10 @@ static int __devexit ds1307_remove(struct i2c_client *client) 
		cancel_work_sync(&ds1307->work);

	}



	if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))

		sysfs_remove_bin_file(&client->dev.kobj, &nvram);

	if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags)) {

		sysfs_remove_bin_file(&client->dev.kobj, ds1307->nvram);

		kfree(ds1307->nvram);

	}



	rtc_device_unregister(ds1307->rtc);

	kfree(ds1307);