From 30e7b039b1f9a6d5a4e50df5469a4f347ea1aa77 Mon Sep 17 00:00:00 2001 From: Ed Swierk Date: Tue, 31 Mar 2009 15:24:56 -0700 Subject: [PATCH] rtc-ds1307: true SMBus compatibility Allow the rtc-ds1307 driver to work with SMBus controllers like nforce2 that do not support i2c block transfers. Signed-off-by: Ed Swierk Acked-by: Jean Delvare Acked-by: David Brownell Cc: Alessandro Zummo Cc: BARRE Sebastien Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-ds1307.c | 109 ++++++++++++++++++++++++++++++++++----- 1 file changed, 97 insertions(+), 12 deletions(-) diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 7e5155e88ac7..1c975e6439b3 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -94,6 +94,10 @@ struct ds1307 { struct i2c_client *client; struct rtc_device *rtc; struct work_struct work; + s32 (*read_block_data)(struct i2c_client *client, u8 command, + u8 length, u8 *values); + s32 (*write_block_data)(struct i2c_client *client, u8 command, + u8 length, const u8 *values); }; struct chip_desc { @@ -132,6 +136,79 @@ MODULE_DEVICE_TABLE(i2c, ds1307_id); /*----------------------------------------------------------------------*/ +#define BLOCK_DATA_MAX_TRIES 10 + +static s32 ds1307_read_block_data_once(struct i2c_client *client, u8 command, + u8 length, u8 *values) +{ + s32 i, data; + + for (i = 0; i < length; i++) { + data = i2c_smbus_read_byte_data(client, command + i); + if (data < 0) + return data; + values[i] = data; + } + return i; +} + +static s32 ds1307_read_block_data(struct i2c_client *client, u8 command, + u8 length, u8 *values) +{ + u8 oldvalues[I2C_SMBUS_BLOCK_MAX]; + s32 ret; + int tries = 0; + + dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length); + ret = ds1307_read_block_data_once(client, command, length, values); + if (ret < 0) + return ret; + do { + if (++tries > BLOCK_DATA_MAX_TRIES) { + dev_err(&client->dev, + "ds1307_read_block_data failed\n"); + return -EIO; + } + memcpy(oldvalues, values, length); + ret = ds1307_read_block_data_once(client, command, length, + values); + if (ret < 0) + return ret; + } while (memcmp(oldvalues, values, length)); + return length; +} + +static s32 ds1307_write_block_data(struct i2c_client *client, u8 command, + u8 length, const u8 *values) +{ + u8 currvalues[I2C_SMBUS_BLOCK_MAX]; + int tries = 0; + + dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length); + do { + s32 i, ret; + + if (++tries > BLOCK_DATA_MAX_TRIES) { + dev_err(&client->dev, + "ds1307_write_block_data failed\n"); + return -EIO; + } + for (i = 0; i < length; i++) { + ret = i2c_smbus_write_byte_data(client, command + i, + values[i]); + if (ret < 0) + return ret; + } + ret = ds1307_read_block_data_once(client, command, length, + currvalues); + if (ret < 0) + return ret; + } while (memcmp(currvalues, values, length)); + 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 @@ -202,7 +279,7 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t) int tmp; /* read the RTC date and time registers all at once */ - tmp = i2c_smbus_read_i2c_block_data(ds1307->client, + tmp = ds1307->read_block_data(ds1307->client, DS1307_REG_SECS, 7, ds1307->regs); if (tmp != 7) { dev_err(dev, "%s error %d\n", "read", tmp); @@ -279,7 +356,7 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t) "write", buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6]); - result = i2c_smbus_write_i2c_block_data(ds1307->client, 0, 7, buf); + result = ds1307->write_block_data(ds1307->client, 0, 7, buf); if (result < 0) { dev_err(dev, "%s error %d\n", "write", result); return result; @@ -297,7 +374,7 @@ static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t) return -EINVAL; /* read all ALARM1, ALARM2, and status registers at once */ - ret = i2c_smbus_read_i2c_block_data(client, + ret = ds1307->read_block_data(client, DS1339_REG_ALARM1_SECS, 9, ds1307->regs); if (ret != 9) { dev_err(dev, "%s error %d\n", "alarm read", ret); @@ -356,7 +433,7 @@ static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t) t->enabled, t->pending); /* read current status of both alarms and the chip */ - ret = i2c_smbus_read_i2c_block_data(client, + ret = ds1307->read_block_data(client, DS1339_REG_ALARM1_SECS, 9, buf); if (ret != 9) { dev_err(dev, "%s error %d\n", "alarm write", ret); @@ -391,7 +468,7 @@ static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t) } buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I); - ret = i2c_smbus_write_i2c_block_data(client, + ret = ds1307->write_block_data(client, DS1339_REG_ALARM1_SECS, 9, buf); if (ret < 0) { dev_err(dev, "can't set alarm time\n"); @@ -479,7 +556,7 @@ ds1307_nvram_read(struct kobject *kobj, struct bin_attribute *attr, if (unlikely(!count)) return count; - result = i2c_smbus_read_i2c_block_data(client, 8 + off, count, buf); + result = ds1307->read_block_data(client, 8 + off, count, buf); if (result < 0) dev_err(&client->dev, "%s error %d\n", "nvram read", result); return result; @@ -490,9 +567,11 @@ ds1307_nvram_write(struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { struct i2c_client *client; + struct ds1307 *ds1307; int result; client = kobj_to_i2c_client(kobj); + ds1307 = i2c_get_clientdata(client); if (unlikely(off >= NVRAM_SIZE)) return -EFBIG; @@ -501,7 +580,7 @@ ds1307_nvram_write(struct kobject *kobj, struct bin_attribute *attr, if (unlikely(!count)) return count; - result = i2c_smbus_write_i2c_block_data(client, 8 + off, count, buf); + result = ds1307->write_block_data(client, 8 + off, count, buf); if (result < 0) { dev_err(&client->dev, "%s error %d\n", "nvram write", result); return result; @@ -535,9 +614,8 @@ static int __devinit ds1307_probe(struct i2c_client *client, int want_irq = false; unsigned char *buf; - if (!i2c_check_functionality(adapter, - I2C_FUNC_SMBUS_WRITE_BYTE_DATA | - I2C_FUNC_SMBUS_I2C_BLOCK)) + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA) + && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) return -EIO; if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL))) @@ -547,6 +625,13 @@ static int __devinit ds1307_probe(struct i2c_client *client, i2c_set_clientdata(client, ds1307); ds1307->type = id->driver_data; 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; + } else { + ds1307->read_block_data = ds1307_read_block_data; + ds1307->write_block_data = ds1307_write_block_data; + } switch (ds1307->type) { case ds_1337: @@ -557,7 +642,7 @@ static int __devinit ds1307_probe(struct i2c_client *client, want_irq = true; } /* get registers that the "rtc" read below won't read... */ - tmp = i2c_smbus_read_i2c_block_data(ds1307->client, + tmp = ds1307->read_block_data(ds1307->client, DS1337_REG_CONTROL, 2, buf); if (tmp != 2) { pr_debug("read error %d\n", tmp); @@ -595,7 +680,7 @@ static int __devinit ds1307_probe(struct i2c_client *client, read_rtc: /* read RTC registers */ - tmp = i2c_smbus_read_i2c_block_data(ds1307->client, 0, 8, buf); + tmp = ds1307->read_block_data(ds1307->client, 0, 8, buf); if (tmp != 8) { pr_debug("read error %d\n", tmp); err = -EIO; -- 2.30.2