diff options
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/max6650.c | 108 |
1 files changed, 67 insertions, 41 deletions
diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c index c87517aee83a..a993b44ed538 100644 --- a/drivers/hwmon/max6650.c +++ b/drivers/hwmon/max6650.c @@ -185,6 +185,30 @@ static struct max6650_data *max6650_update_device(struct device *dev) return data; } +/* + * Change the operating mode of the chip (if needed). + * mode is one of the MAX6650_CFG_MODE_* values. + */ +static int max6650_set_operating_mode(struct max6650_data *data, u8 mode) +{ + int result; + u8 config = data->config; + + if (mode == (config & MAX6650_CFG_MODE_MASK)) + return 0; + + config = (config & ~MAX6650_CFG_MODE_MASK) | mode; + + result = i2c_smbus_write_byte_data(data->client, MAX6650_REG_CONFIG, + config); + if (result < 0) + return result; + + data->config = config; + + return 0; +} + static ssize_t get_fan(struct device *dev, struct device_attribute *devattr, char *buf) { @@ -266,18 +290,12 @@ static ssize_t get_target(struct device *dev, struct device_attribute *devattr, return sprintf(buf, "%d\n", rpm); } -static ssize_t set_target(struct device *dev, struct device_attribute *devattr, - const char *buf, size_t count) +static int max6650_set_target(struct max6650_data *data, unsigned long rpm) { - struct max6650_data *data = dev_get_drvdata(dev); - struct i2c_client *client = data->client; int kscale, ktach; - unsigned long rpm; - int err; - err = kstrtoul(buf, 10, &rpm); - if (err) - return err; + if (rpm == 0) + return max6650_set_operating_mode(data, MAX6650_CFG_MODE_OFF); rpm = clamp_val(rpm, FAN_RPM_MIN, FAN_RPM_MAX); @@ -288,8 +306,6 @@ static ssize_t set_target(struct device *dev, struct device_attribute *devattr, * KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1 */ - mutex_lock(&data->update_lock); - kscale = DIV_FROM_REG(data->config); ktach = ((clock * kscale) / (256 * rpm / 60)) - 1; if (ktach < 0) @@ -298,10 +314,30 @@ static ssize_t set_target(struct device *dev, struct device_attribute *devattr, ktach = 255; data->speed = ktach; - i2c_smbus_write_byte_data(client, MAX6650_REG_SPEED, data->speed); + return i2c_smbus_write_byte_data(data->client, MAX6650_REG_SPEED, + data->speed); +} + +static ssize_t set_target(struct device *dev, struct device_attribute *devattr, + const char *buf, size_t count) +{ + struct max6650_data *data = dev_get_drvdata(dev); + unsigned long rpm; + int err; + + err = kstrtoul(buf, 10, &rpm); + if (err) + return err; + + mutex_lock(&data->update_lock); + + err = max6650_set_target(data, rpm); mutex_unlock(&data->update_lock); + if (err < 0) + return err; + return count; } @@ -355,12 +391,11 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr, data->dac = 180 - (180 * pwm)/255; else data->dac = 76 - (76 * pwm)/255; - - i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac); + err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac); mutex_unlock(&data->update_lock); - return count; + return err < 0 ? err : count; } /* @@ -369,14 +404,14 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr, * 0 = Fan always on * 1 = Open loop, Voltage is set according to speed, not regulated. * 2 = Closed loop, RPM for all fans regulated by fan1 tachometer + * 3 = Fan off */ - static ssize_t get_enable(struct device *dev, struct device_attribute *devattr, char *buf) { struct max6650_data *data = max6650_update_device(dev); int mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4; - int sysfs_modes[4] = {0, 1, 2, 1}; + int sysfs_modes[4] = {0, 3, 2, 1}; return sprintf(buf, "%d\n", sysfs_modes[mode]); } @@ -385,25 +420,25 @@ static ssize_t set_enable(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) { struct max6650_data *data = dev_get_drvdata(dev); - struct i2c_client *client = data->client; - int max6650_modes[3] = {0, 3, 2}; unsigned long mode; int err; + const u8 max6650_modes[] = { + MAX6650_CFG_MODE_ON, + MAX6650_CFG_MODE_OPEN_LOOP, + MAX6650_CFG_MODE_CLOSED_LOOP, + MAX6650_CFG_MODE_OFF, + }; err = kstrtoul(buf, 10, &mode); if (err) return err; - if (mode > 2) + if (mode >= ARRAY_SIZE(max6650_modes)) return -EINVAL; mutex_lock(&data->update_lock); - data->config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG); - data->config = (data->config & ~MAX6650_CFG_MODE_MASK) - | (max6650_modes[mode] << 4); - - i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, data->config); + max6650_set_operating_mode(data, max6650_modes[mode]); mutex_unlock(&data->update_lock); @@ -582,6 +617,7 @@ static int max6650_init_client(struct max6650_data *data, int err = -EIO; u32 voltage; u32 prescale; + u32 target_rpm; if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt", &voltage)) @@ -642,22 +678,6 @@ static int max6650_init_client(struct max6650_data *data, (config & MAX6650_CFG_V12) ? 12 : 5, 1 << (config & MAX6650_CFG_PRESCALER_MASK)); - /* - * If mode is set to "full off", we change it to "open loop" and - * set DAC to 255, which has the same effect. We do this because - * there's no "full off" mode defined in hwmon specifications. - */ - - if ((config & MAX6650_CFG_MODE_MASK) == MAX6650_CFG_MODE_OFF) { - dev_dbg(dev, "Change mode to open loop, full off.\n"); - config = (config & ~MAX6650_CFG_MODE_MASK) - | MAX6650_CFG_MODE_OPEN_LOOP; - if (i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, 255)) { - dev_err(dev, "DAC write error, aborting.\n"); - return err; - } - } - if (i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, config)) { dev_err(dev, "Config write error, aborting.\n"); return err; @@ -666,6 +686,12 @@ static int max6650_init_client(struct max6650_data *data, data->config = config; data->count = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT); + if (!of_property_read_u32(client->dev.of_node, "maxim,fan-target-rpm", + &target_rpm)) { + max6650_set_target(data, target_rpm); + max6650_set_operating_mode(data, MAX6650_CFG_MODE_CLOSED_LOOP); + } + return 0; } |