Add support for showing and changing the bus frequency via sysfs. Tested on a DLN2 adapter run in U2C-12 compatibility mode.
Cc: Guenter Roeck <[email protected]> Signed-off-by: Octavian Purdila <[email protected]> --- drivers/i2c/busses/i2c-diolan-u2c.c | 49 +++++++++++++++++++++++++------------ 1 file changed, 34 insertions(+), 15 deletions(-) diff --git a/drivers/i2c/busses/i2c-diolan-u2c.c b/drivers/i2c/busses/i2c-diolan-u2c.c index b19a310..ff4e120 100644 --- a/drivers/i2c/busses/i2c-diolan-u2c.c +++ b/drivers/i2c/busses/i2c-diolan-u2c.c @@ -71,6 +71,9 @@ #define U2C_I2C_FREQ_STD 100000 #define U2C_I2C_FREQ(s) (1000000 / (2 * (s - 1) + 10)) +#define U2C_I2C_MIN_FREQ U2C_I2C_FREQ(U2C_I2C_SPEED_2KHZ) +#define U2C_I2C_MAX_FREQ U2C_I2C_FREQ_FAST + #define DIOLAN_USB_TIMEOUT 100 /* in ms */ #define DIOLAN_SYNC_TIMEOUT 20 /* in ms */ @@ -298,31 +301,24 @@ static void diolan_get_serial(struct i2c_diolan_u2c *dev) } } -static int diolan_init(struct i2c_diolan_u2c *dev) +static int diolan_set_freq(struct i2c_adapter *adapter, unsigned int *frequency) { + struct i2c_diolan_u2c *dev = i2c_get_adapdata(adapter); int speed, ret; - if (frequency >= 200000) { + if (*frequency >= 200000) { speed = U2C_I2C_SPEED_FAST; - frequency = U2C_I2C_FREQ_FAST; - } else if (frequency >= 100000 || frequency == 0) { + *frequency = U2C_I2C_FREQ_FAST; + } else if (*frequency >= 100000 || *frequency == 0) { speed = U2C_I2C_SPEED_STD; - frequency = U2C_I2C_FREQ_STD; + *frequency = U2C_I2C_FREQ_STD; } else { - speed = U2C_I2C_SPEED(frequency); + speed = U2C_I2C_SPEED(*frequency); if (speed > U2C_I2C_SPEED_2KHZ) speed = U2C_I2C_SPEED_2KHZ; - frequency = U2C_I2C_FREQ(speed); + *frequency = U2C_I2C_FREQ(speed); } - dev_info(&dev->interface->dev, - "Diolan U2C at USB bus %03d address %03d speed %d Hz\n", - dev->usb_dev->bus->busnum, dev->usb_dev->devnum, frequency); - - diolan_flush_input(dev); - diolan_fw_version(dev); - diolan_get_serial(dev); - /* Set I2C speed */ ret = diolan_set_speed(dev, speed); if (ret < 0) @@ -336,6 +332,23 @@ static int diolan_init(struct i2c_diolan_u2c *dev) if (speed != U2C_I2C_SPEED_FAST) ret = diolan_set_clock_synch_timeout(dev, DIOLAN_SYNC_TIMEOUT); + return 0; +} + +static int diolan_init(struct i2c_diolan_u2c *dev) +{ + int ret; + + diolan_flush_input(dev); + diolan_fw_version(dev); + diolan_get_serial(dev); + + ret = diolan_set_freq(&dev->adapter, &frequency); + + dev_info(&dev->interface->dev, + "Diolan U2C at USB bus %03d address %03d speed %d Hz\n", + dev->usb_dev->bus->busnum, dev->usb_dev->devnum, frequency); + return ret; } @@ -471,6 +484,9 @@ static int diolan_u2c_probe(struct usb_interface *interface, dev->adapter.owner = THIS_MODULE; dev->adapter.class = I2C_CLASS_HWMON; dev->adapter.algo = &diolan_usb_algorithm; + dev->adapter.min_freq = U2C_I2C_MIN_FREQ; + dev->adapter.max_freq = U2C_I2C_MAX_FREQ; + dev->adapter.set_freq = diolan_set_freq; i2c_set_adapdata(&dev->adapter, dev); snprintf(dev->adapter.name, sizeof(dev->adapter.name), DRIVER_NAME " at bus %03d device %03d", @@ -485,6 +501,9 @@ static int diolan_u2c_probe(struct usb_interface *interface, goto error_free; } + /* set the current bus frequency */ + dev->adapter.freq = frequency; + /* and finally attach to i2c layer */ ret = i2c_add_adapter(&dev->adapter); if (ret < 0) { -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
