diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/rtc/rtc-ds1307.c | 78 |
1 files changed, 47 insertions, 31 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 84ab971978cf..cd188ab72f79 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -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 @@ read_rtc: 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); |