Messages in this thread Patch in this message | | | Subject | Re: [PATCH v3] rtc: ds1307: generalise ram size and offset | From | Austin Boyle <> | Date | Thu, 12 Jan 2012 11:21:56 +1300 |
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Hi Wolfram,
Thanks for reviewing the patch.
> I think the stuff related to 'offset' should be in a separate patch with > specific commit-msg. Agreed. I will submit a separate patch after this one.
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This patch generalises NVRAM to support RAM with other size and offset, such as the 64 bytes of SRAM on the mcp7941x.
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 +++ 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; + u16 nvram_size; 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; @@ -605,7 +615,6 @@ static struct bin_attribute nvram = { .read = ds1307_nvram_read, .write = ds1307_nvram_write, - .size = NVRAM_SIZE, }; /*----------------------------------------------------------------------*/ @@ -638,7 +647,12 @@ static int __devinit ds1307_probe(struct i2c_client *client, ds1307->client = client; ds1307->type = id->driver_data; - ds1307->offset = 0; + if (chip) { + if (chip->nvram_size) + ds1307->nvram_size = chip->nvram_size; + if (chip->nvram_offset) + ds1307->nvram_offset = chip->nvram_offset; + } buf = ds1307->regs; if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) { @@ -893,11 +907,12 @@ read_rtc: dev_dbg(&client->dev, "got IRQ %d\n", client->irq); } - if (chip && chip->nvram56) { + if (chip && chip->nvram_size) { + 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); } }
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