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Subject[PATCH 2.6.39-rc7] RTC: rtc-ds1307 EEPROM support for ds1388 chip
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This is my patch which extends the NVRAM access functions in the DS1307
driver to support the 512 bytes of EEPROM on the DS1388 chip. Could you
please review the patch? If there are any problems with the way I have
implemented this or suggested improvements I will gladly modify. Thanks!


[PATCH 2.6.39-rc7] RTC: rtc-ds1307 EEPROM support for ds1388 chip

This patch adds support for different sized NVRAM, such as
the 512 bytes of EEPROM on the DS1388 chip.

Signed-off-by: Austin Boyle <austin.boyle@aviatnet.com>
---
diff -upNr a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
--- a/drivers/rtc/rtc-ds1307.c 2011-05-19 13:52:35.114845829 +1200
+++ b/drivers/rtc/rtc-ds1307.c 2011-05-23 16:46:19.168163336 +1200
@@ -95,15 +95,19 @@ enum ds_type {
# define RX8025_BIT_VDET 0x40
# define RX8025_BIT_XST 0x20

+#define DS1307_MAX_NUM_ADDRS 3

struct ds1307 {
u8 offset; /* register's offset */
+ u16 nvram_size;
+ u16 nvram_offset;
+ u8 num_addrs;
u8 regs[11];
enum ds_type type;
unsigned long flags;
#define HAS_NVRAM 0 /* bit 0 == sysfs file active */
#define HAS_ALARM 1 /* bit 1 == irq claimed */
- struct i2c_client *client;
+ struct i2c_client *client[DS1307_MAX_NUM_ADDRS];
struct rtc_device *rtc;
struct work_struct work;
s32 (*read_block_data)(const struct i2c_client *client, u8 command,
@@ -113,23 +117,26 @@ struct ds1307 {
};

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

static const struct chip_desc chips[] = {
[ds_1307] = {
- .nvram56 = 1,
+ .nvram = 1,
},
[ds_1337] = {
.alarm = 1,
},
[ds_1338] = {
- .nvram56 = 1,
+ .nvram = 1,
},
[ds_1339] = {
.alarm = 1,
},
+[ds_1388] = {
+ .nvram = 1,
+},
[ds_1340] = {
},
[ds_3231] = {
@@ -248,7 +255,7 @@ static void ds1307_work(struct work_stru
int stat, control;

ds1307 = container_of(work, struct ds1307, work);
- client = ds1307->client;
+ client = ds1307->client[0];
lock = &ds1307->rtc->ops_lock;

mutex_lock(lock);
@@ -294,7 +301,7 @@ static int ds1307_get_time(struct device
int tmp;

/* read the RTC date and time registers all at once */
- tmp = ds1307->read_block_data(ds1307->client,
+ tmp = ds1307->read_block_data(ds1307->client[0],
ds1307->offset, 7, ds1307->regs);
if (tmp != 7) {
dev_err(dev, "%s error %d\n", "read", tmp);
@@ -372,7 +379,7 @@ static int ds1307_set_time(struct device
"write", buf[0], buf[1], buf[2], buf[3],
buf[4], buf[5], buf[6]);

- result = ds1307->write_block_data(ds1307->client,
+ result = ds1307->write_block_data(ds1307->client[0],
ds1307->offset, 7, buf);
if (result < 0) {
dev_err(dev, "%s error %d\n", "write", result);
@@ -530,8 +537,6 @@ 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,
@@ -540,18 +545,39 @@ ds1307_nvram_read(struct file *filp, str
struct i2c_client *client;
struct ds1307 *ds1307;
int result;
+ unsigned int addr = 0;

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);
+ if (ds1307->nvram_offset < 0xff) { /* ds1307, ds1338 */
+ result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
count, buf);
+ } else { /* ds1388 */
+ if ((off <= 0x00ff) && (off + count > 0x00ff)) { /* read spans two
blocks */
+ client = ds1307->client[1]; /* first block */
+ addr = (unsigned int)off;
+ result = ds1307->read_block_data(client, addr, (0x100-addr), buf);
+ client = ds1307->client[2]; /* second block */
+ result += ds1307->read_block_data(client, 0x00, (count+addr-0x100),
(buf+0x100-addr));
+
+ } else { /* read spans one blocks */
+ if (off <= 0x00ff) {
+ client = ds1307->client[1];
+ addr = (unsigned int)off;
+ } else if (off <= 0x0200) {
+ client = ds1307->client[2];
+ addr = (unsigned int)off - 0x100;
+ }
+ result = ds1307->read_block_data(client, addr, count, buf);
+ }
+ }
if (result < 0)
dev_err(&client->dev, "%s error %d\n", "nvram read", result);
return result;
@@ -565,18 +591,40 @@ ds1307_nvram_write(struct file *filp, st
struct i2c_client *client;
struct ds1307 *ds1307;
int result;
+ unsigned int addr = 0;

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);
+ if (ds1307->nvram_offset < 0xff) { /* ds1307, ds1338 */
+ result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
count, buf);
+ } else { /* ds1388 */
+ if ((off <= 0x00ff) && ((off + count) > 0x00ff)) { /* read spans two
blocks */
+ client = ds1307->client[1]; /* first block */
+ addr = (unsigned int)off;
+ result = ds1307->write_block_data(client, addr, (0x100-addr), buf);
+ client = ds1307->client[2]; /* second block */
+ result = ds1307->write_block_data(client, 0x00, (addr+count-0x100),
(buf+0x100-addr));
+
+ } else { /* Device address/offset translation */
+ dev_dbg(&client->dev, "Write spans one block\n");
+ if (off <= 0x00ff) {
+ client = ds1307->client[1];
+ addr = (unsigned int)off;
+ } else if (off <= 0x0200) {
+ client = ds1307->client[2];
+ addr = (unsigned int)off - 0x100;
+ }
+ result = ds1307->write_block_data(client, addr, count, buf);
+ }
+ }
if (result < 0) {
dev_err(&client->dev, "%s error %d\n", "nvram write", result);
return result;
@@ -592,7 +640,6 @@ static struct bin_attribute nvram = {

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

/*----------------------------------------------------------------------*/
@@ -605,6 +652,7 @@ static int __devinit ds1307_probe(struct
struct ds1307 *ds1307;
int err = -ENODEV;
int tmp;
+ int i;
const struct chip_desc *chip = &chips[id->driver_data];
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
int want_irq = false;
@@ -624,9 +672,10 @@ static int __devinit ds1307_probe(struct

i2c_set_clientdata(client, ds1307);

- ds1307->client = client;
+ ds1307->client[0] = client;
ds1307->type = id->driver_data;
ds1307->offset = 0;
+ ds1307->num_addrs = 1;

buf = ds1307->regs;
if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
@@ -642,12 +691,12 @@ static int __devinit ds1307_probe(struct
case ds_1339:
case ds_3231:
/* has IRQ? */
- if (ds1307->client->irq > 0 && chip->alarm) {
+ if (client->irq > 0 && chip->alarm) {
INIT_WORK(&ds1307->work, ds1307_work);
want_irq = true;
}
/* get registers that the "rtc" read below won't read... */
- tmp = ds1307->read_block_data(ds1307->client,
+ tmp = ds1307->read_block_data(client,
DS1337_REG_CONTROL, 2, buf);
if (tmp != 2) {
pr_debug("read error %d\n", tmp);
@@ -681,7 +730,7 @@ static int __devinit ds1307_probe(struct
break;

case rx_8025:
- tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
+ tmp = i2c_smbus_read_i2c_block_data(client,
RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
if (tmp != 2) {
pr_debug("read error %d\n", tmp);
@@ -747,6 +796,14 @@ static int __devinit ds1307_probe(struct
break;
case ds_1388:
ds1307->offset = 1; /* Seconds starts at 1 */
+ ds1307->num_addrs = 3; /* uses 3 I2C addrs */
+ ds1307->nvram_size = 512; /* 512 bytes EEPROM */
+ ds1307->nvram_offset = 0xff;
+ break;
+ case ds_1307:
+ case ds_1338:
+ ds1307->nvram_size = 56; /* 56 bytes NVRAM */
+ ds1307->nvram_offset = 8;
break;
default:
break;
@@ -754,7 +811,7 @@ static int __devinit ds1307_probe(struct

read_rtc:
/* read RTC registers */
- tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
+ tmp = ds1307->read_block_data(client, ds1307->offset, 8, buf);
if (tmp != 8) {
pr_debug("read error %d\n", tmp);
err = -EIO;
@@ -866,7 +923,8 @@ read_rtc:
dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
}

- if (chip->nvram56) {
+ if (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);
@@ -874,8 +932,26 @@ read_rtc:
}
}

+ /* use dummy devices for multiple address chips */
+ for (i = 1; i < ds1307->num_addrs; i++) {
+ ds1307->client[i] = i2c_new_dummy(client->adapter, client->addr + i);
+ if (!ds1307->client[i]) {
+ dev_err(&client->dev, "address 0x%02x unavailable\n",
+ client->addr + i);
+ err = -EADDRINUSE;
+ goto err_clients;
+ }
+ i2c_set_clientdata(ds1307->client[i], ds1307);
+ }
+
return 0;

+err_clients:
+ for (i = 1; i < ds1307->num_addrs; i++) {
+ if (ds1307->client[i]) {
+ i2c_unregister_device(ds1307->client[i]);
+ }
+ }
exit_irq:
rtc_device_unregister(ds1307->rtc);
exit_free:


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