diff options
Diffstat (limited to 'drivers/hwmon/max6650.c')
| -rw-r--r-- | drivers/hwmon/max6650.c | 155 |
1 files changed, 103 insertions, 52 deletions
diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c index 162a520f4bd6..a993b44ed538 100644 --- a/drivers/hwmon/max6650.c +++ b/drivers/hwmon/max6650.c @@ -39,6 +39,7 @@ #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/err.h> +#include <linux/of_device.h> /* * Insmod parameters @@ -48,7 +49,7 @@ static int fan_voltage; /* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */ static int prescaler; -/* clock: The clock frequency of the chip the driver should assume */ +/* clock: The clock frequency of the chip (max6651 can be clocked externally) */ static int clock = 254000; module_param(fan_voltage, int, S_IRUGO); @@ -133,6 +134,19 @@ static const u8 tach_reg[] = { MAX6650_REG_TACH3, }; +static const struct of_device_id max6650_dt_match[] = { + { + .compatible = "maxim,max6650", + .data = (void *)1 + }, + { + .compatible = "maxim,max6651", + .data = (void *)4 + }, + { }, +}; +MODULE_DEVICE_TABLE(of, max6650_dt_match); + static struct max6650_data *max6650_update_device(struct device *dev) { struct max6650_data *data = dev_get_drvdata(dev); @@ -171,6 +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) { @@ -252,18 +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); @@ -274,8 +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) @@ -284,10 +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; } @@ -341,12 +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; } /* @@ -355,14 +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]); } @@ -371,25 +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); @@ -566,6 +615,18 @@ static int max6650_init_client(struct max6650_data *data, struct device *dev = &client->dev; int config; int err = -EIO; + u32 voltage; + u32 prescale; + u32 target_rpm; + + if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt", + &voltage)) + voltage = fan_voltage; + else + voltage /= 1000000; /* Microvolts to volts */ + if (of_property_read_u32(dev->of_node, "maxim,fan-prescale", + &prescale)) + prescale = prescaler; config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG); @@ -574,7 +635,7 @@ static int max6650_init_client(struct max6650_data *data, return err; } - switch (fan_voltage) { + switch (voltage) { case 0: break; case 5: @@ -584,14 +645,10 @@ static int max6650_init_client(struct max6650_data *data, config |= MAX6650_CFG_V12; break; default: - dev_err(dev, "illegal value for fan_voltage (%d)\n", - fan_voltage); + dev_err(dev, "illegal value for fan_voltage (%d)\n", voltage); } - dev_info(dev, "Fan voltage is set to %dV.\n", - (config & MAX6650_CFG_V12) ? 12 : 5); - - switch (prescaler) { + switch (prescale) { case 0: break; case 1: @@ -614,28 +671,13 @@ static int max6650_init_client(struct max6650_data *data, | MAX6650_CFG_PRESCALER_16; break; default: - dev_err(dev, "illegal value for prescaler (%d)\n", prescaler); + dev_err(dev, "illegal value for prescaler (%d)\n", prescale); } - dev_info(dev, "Prescaler is set to %d.\n", + dev_info(dev, "Fan voltage: %dV, prescaler: %d.\n", + (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; @@ -644,6 +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; } @@ -651,6 +699,8 @@ static int max6650_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; + const struct of_device_id *of_id = + of_match_device(of_match_ptr(max6650_dt_match), dev); struct max6650_data *data; struct device *hwmon_dev; int err; @@ -661,7 +711,7 @@ static int max6650_probe(struct i2c_client *client, data->client = client; mutex_init(&data->update_lock); - data->nr_fans = id->driver_data; + data->nr_fans = of_id ? (int)(uintptr_t)of_id->data : id->driver_data; /* * Initialize the max6650 chip @@ -691,6 +741,7 @@ MODULE_DEVICE_TABLE(i2c, max6650_id); static struct i2c_driver max6650_driver = { .driver = { .name = "max6650", + .of_match_table = of_match_ptr(max6650_dt_match), }, .probe = max6650_probe, .id_table = max6650_id, |