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path: root/drivers/rtc/rtc-ds1307.c
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Diffstat (limited to 'drivers/rtc/rtc-ds1307.c')
-rw-r--r--drivers/rtc/rtc-ds1307.c74
1 files changed, 63 insertions, 11 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 970a236b147..b53992ab309 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -4,6 +4,7 @@
* Copyright (C) 2005 James Chapman (ds1337 core)
* Copyright (C) 2006 David Brownell
* Copyright (C) 2009 Matthias Fuchs (rx8025 support)
+ * Copyright (C) 2012 Bertrand Achard (nvram access fixes)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -196,7 +197,7 @@ static s32 ds1307_read_block_data_once(const struct i2c_client *client,
static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
u8 length, u8 *values)
{
- u8 oldvalues[I2C_SMBUS_BLOCK_MAX];
+ u8 oldvalues[255];
s32 ret;
int tries = 0;
@@ -222,7 +223,7 @@ static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
u8 length, const u8 *values)
{
- u8 currvalues[I2C_SMBUS_BLOCK_MAX];
+ u8 currvalues[255];
int tries = 0;
dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
@@ -250,6 +251,57 @@ static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
/*----------------------------------------------------------------------*/
+/* These RTC devices are not designed to be connected to a SMbus adapter.
+ SMbus limits block operations length to 32 bytes, whereas it's not
+ limited on I2C buses. As a result, accesses may exceed 32 bytes;
+ in that case, split them into smaller blocks */
+
+static s32 ds1307_native_smbus_write_block_data(const struct i2c_client *client,
+ u8 command, u8 length, const u8 *values)
+{
+ u8 suboffset = 0;
+
+ if (length <= I2C_SMBUS_BLOCK_MAX)
+ return i2c_smbus_write_i2c_block_data(client,
+ command, length, values);
+
+ while (suboffset < length) {
+ s32 retval = i2c_smbus_write_i2c_block_data(client,
+ command + suboffset,
+ min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
+ values + suboffset);
+ if (retval < 0)
+ return retval;
+
+ suboffset += I2C_SMBUS_BLOCK_MAX;
+ }
+ return length;
+}
+
+static s32 ds1307_native_smbus_read_block_data(const struct i2c_client *client,
+ u8 command, u8 length, u8 *values)
+{
+ u8 suboffset = 0;
+
+ if (length <= I2C_SMBUS_BLOCK_MAX)
+ return i2c_smbus_read_i2c_block_data(client,
+ command, length, values);
+
+ while (suboffset < length) {
+ s32 retval = i2c_smbus_read_i2c_block_data(client,
+ command + suboffset,
+ min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
+ values + suboffset);
+ if (retval < 0)
+ return retval;
+
+ suboffset += I2C_SMBUS_BLOCK_MAX;
+ }
+ return length;
+}
+
+/*----------------------------------------------------------------------*/
+
/*
* The IRQ logic includes a "real" handler running in IRQ context just
* long enough to schedule this workqueue entry. We need a task context
@@ -646,8 +698,8 @@ static int ds1307_probe(struct i2c_client *client,
buf = ds1307->regs;
if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
- ds1307->read_block_data = i2c_smbus_read_i2c_block_data;
- ds1307->write_block_data = i2c_smbus_write_i2c_block_data;
+ ds1307->read_block_data = ds1307_native_smbus_read_block_data;
+ ds1307->write_block_data = ds1307_native_smbus_write_block_data;
} else {
ds1307->read_block_data = ds1307_read_block_data;
ds1307->write_block_data = ds1307_write_block_data;
@@ -661,7 +713,7 @@ static int ds1307_probe(struct i2c_client *client,
tmp = ds1307->read_block_data(ds1307->client,
DS1337_REG_CONTROL, 2, buf);
if (tmp != 2) {
- pr_debug("read error %d\n", tmp);
+ dev_dbg(&client->dev, "read error %d\n", tmp);
err = -EIO;
goto exit_free;
}
@@ -700,7 +752,7 @@ static int ds1307_probe(struct i2c_client *client,
tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
if (tmp != 2) {
- pr_debug("read error %d\n", tmp);
+ dev_dbg(&client->dev, "read error %d\n", tmp);
err = -EIO;
goto exit_free;
}
@@ -744,7 +796,7 @@ static int ds1307_probe(struct i2c_client *client,
tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
if (tmp != 2) {
- pr_debug("read error %d\n", tmp);
+ dev_dbg(&client->dev, "read error %d\n", tmp);
err = -EIO;
goto exit_free;
}
@@ -772,7 +824,7 @@ read_rtc:
/* read RTC registers */
tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
if (tmp != 8) {
- pr_debug("read error %d\n", tmp);
+ dev_dbg(&client->dev, "read error %d\n", tmp);
err = -EIO;
goto exit_free;
}
@@ -814,7 +866,7 @@ read_rtc:
tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
if (tmp < 0) {
- pr_debug("read error %d\n", tmp);
+ dev_dbg(&client->dev, "read error %d\n", tmp);
err = -EIO;
goto exit_free;
}
@@ -908,8 +960,8 @@ read_rtc:
ds1307->nvram->attr.name = "nvram";
ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;
sysfs_bin_attr_init(ds1307->nvram);
- ds1307->nvram->read = ds1307_nvram_read,
- ds1307->nvram->write = ds1307_nvram_write,
+ 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);
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-17 01:55:50 +0000