From d643a49ae16c755b3dc2ef897438b7d9c6dd488b Mon Sep 17 00:00:00 2001 From: Andreas Werner Date: Thu, 23 Jan 2014 15:55:20 -0800 Subject: drivers/rtc/rtc-rx8581.c: add SMBus-only adapters support Add support for SMBus-only adapters (e.g. i2c-piix4). The driver has implemented only support for I2C adapters which implement the I2C_FUNC_SMBUS_I2C_BLOCK functionality before. With this patch it is possible to load and use the RTC driver with I2C and SMBUS adapters like the rtc-ds1307 does. Tested on AMD G Series Platform (i2c-piix4 adapter driver). Signed-off-by: Andreas Werner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c index 00b0eb7..de8d9c4 100644 --- a/drivers/rtc/rtc-rx8581.c +++ b/drivers/rtc/rtc-rx8581.c @@ -52,8 +52,45 @@ #define RX8581_CTRL_STOP 0x02 /* STOP bit */ #define RX8581_CTRL_RESET 0x01 /* RESET bit */ +struct rx8581 { + struct i2c_client *client; + struct rtc_device *rtc; + s32 (*read_block_data)(const struct i2c_client *client, u8 command, + u8 length, u8 *values); + s32 (*write_block_data)(const struct i2c_client *client, u8 command, + u8 length, const u8 *values); +}; + static struct i2c_driver rx8581_driver; +static int rx8581_read_block_data(const 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 int rx8581_write_block_data(const struct i2c_client *client, u8 command, + u8 length, const u8 *values) +{ + s32 i, ret; + + for (i = 0; i < length; i++) { + ret = i2c_smbus_write_byte_data(client, command + i, + values[i]); + if (ret < 0) + return ret; + } + return length; +} + /* * In the routines that deal directly with the rx8581 hardware, we use * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. @@ -62,6 +99,7 @@ static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm) { unsigned char date[7]; int data, err; + struct rx8581 *rx8581 = i2c_get_clientdata(client); /* First we ensure that the "update flag" is not set, we read the * time and date then re-read the "update flag". If the update flag @@ -80,14 +118,13 @@ static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm) err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG, (data & ~RX8581_FLAG_UF)); if (err != 0) { - dev_err(&client->dev, "Unable to write device " - "flags\n"); + dev_err(&client->dev, "Unable to write device flags\n"); return -EIO; } } /* Now read time and date */ - err = i2c_smbus_read_i2c_block_data(client, RX8581_REG_SC, + err = rx8581->read_block_data(client, RX8581_REG_SC, 7, date); if (err < 0) { dev_err(&client->dev, "Unable to read date\n"); @@ -140,6 +177,7 @@ static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm) { int data, err; unsigned char buf[7]; + struct rx8581 *rx8581 = i2c_get_clientdata(client); dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " "mday=%d, mon=%d, year=%d, wday=%d\n", @@ -176,7 +214,7 @@ static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm) } /* write register's data */ - err = i2c_smbus_write_i2c_block_data(client, RX8581_REG_SC, 7, buf); + err = rx8581->write_block_data(client, RX8581_REG_SC, 7, buf); if (err < 0) { dev_err(&client->dev, "Unable to write to date registers\n"); return -EIO; @@ -231,22 +269,39 @@ static const struct rtc_class_ops rx8581_rtc_ops = { static int rx8581_probe(struct i2c_client *client, const struct i2c_device_id *id) { - struct rtc_device *rtc; + struct rx8581 *rx8581; dev_dbg(&client->dev, "%s\n", __func__); - if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) - return -ENODEV; + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA) + && !i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) + return -EIO; - dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); + rx8581 = devm_kzalloc(&client->dev, sizeof(struct rx8581), GFP_KERNEL); + if (!rx8581) + return -ENOMEM; - rtc = devm_rtc_device_register(&client->dev, rx8581_driver.driver.name, - &rx8581_rtc_ops, THIS_MODULE); + i2c_set_clientdata(client, rx8581); + rx8581->client = client; - if (IS_ERR(rtc)) - return PTR_ERR(rtc); + if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) { + rx8581->read_block_data = i2c_smbus_read_i2c_block_data; + rx8581->write_block_data = i2c_smbus_write_i2c_block_data; + } else { + rx8581->read_block_data = rx8581_read_block_data; + rx8581->write_block_data = rx8581_write_block_data; + } - i2c_set_clientdata(client, rtc); + dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); + + rx8581->rtc = devm_rtc_device_register(&client->dev, + rx8581_driver.driver.name, &rx8581_rtc_ops, THIS_MODULE); + + if (IS_ERR(rx8581->rtc)) { + dev_err(&client->dev, + "unable to register the class device\n"); + return PTR_ERR(rx8581->rtc); + } return 0; } -- cgit v0.10.2