lkml.org 
[lkml]   [2011]   [Nov]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH v2] rtc: ds1307: generalise ram size and offset
From
Date
From: Austin Boyle <Austin.Boyle@aviatnet.com>

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

Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: David Anderson <danders.dev@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: Austin Boyle <Austin.Boyle@aviatnet.com>
---
this patch is based on Wolfram Sang's tree:
git://git.pengutronix.de/git/wsa/linux-2.6.git ds1307

patch depends on:
rtc: ds1307: comment and format cleanup 21af5f7bd6
rtc: ds1307: simplify irq setup code 8c63e03627
rtc: ds1307: refactor chip_desc table e246db081d
rtc: add initial support for mcp7941x parts e69bba2d3a

--- a/drivers/rtc/rtc-ds1307.c 2011-10-10 11:22:22.674690998 +1300
+++ b/drivers/rtc/rtc-ds1307.c 2011-11-03 12:17:40.777642801 +1300
@@ -104,6 +104,8 @@ enum ds_type {

struct ds1307 {
u8 offset; /* register's offset */
+ u16 nvram_offset;
+ u16 nvram_size;
u8 regs[11];
enum ds_type type;
unsigned long flags;
@@ -119,19 +121,19 @@ struct ds1307 {
};

struct chip_desc {
- unsigned nvram56:1;
+ unsigned nvram:1;
unsigned alarm:1;
};

static const struct chip_desc chips[last_ds_type] = {
[ds_1307] = {
- .nvram56 = 1,
+ .nvram = 1,
},
[ds_1337] = {
.alarm = 1,
},
[ds_1338] = {
- .nvram56 = 1,
+ .nvram = 1,
},
[ds_1339] = {
.alarm = 1,
@@ -139,6 +141,9 @@ static const struct chip_desc chips[last
[ds_3231] = {
.alarm = 1,
},
+ [mcp7941x] = {
+ .nvram = 1,
+ },
};

static const struct i2c_device_id ds1307_id[] = {
@@ -543,8 +548,6 @@ static const struct rtc_class_ops ds13xx

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

-#define NVRAM_SIZE 56
-
static ssize_t
ds1307_nvram_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr,
@@ -557,14 +560,15 @@ ds1307_nvram_read(struct file *filp, str
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 +586,15 @@ ds1307_nvram_write(struct file *filp, st
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;
@@ -605,7 +610,6 @@ static struct bin_attribute nvram = {

.read = ds1307_nvram_read,
.write = ds1307_nvram_write,
- .size = NVRAM_SIZE,
};

/*----------------------------------------------------------------------*/
@@ -692,6 +696,9 @@ static int __devinit ds1307_probe(struct
break;

case rx_8025:
+ ds1307->nvram_size = 64; /* 64 bytes SRAM */
+ ds1307->nvram_offset = 0x20;
+
tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
if (tmp != 2) {
@@ -758,6 +765,8 @@ static int __devinit ds1307_probe(struct
break;
case ds_1388:
ds1307->offset = 1; /* Seconds starts at 1 */
+ ds1307->nvram_size = 56; /* 56 bytes NVRAM */
+ ds1307->nvram_offset = 8;
break;
default:
break;
@@ -893,11 +902,12 @@ read_rtc:
dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
}

- if (chip && chip->nvram56) {
+ if (chip && chip->nvram) {
+ nvram.size = ds1307->nvram_size;
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");
+ dev_info(&client->dev, "%zd bytes nvram\n", nvram.size);
}
}



\
 
 \ /
  Last update: 2011-11-03 00:37    [W:0.023 / U:15.704 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site