hwmon: (lm85) Add support for ADT7468 high-frequency PWM mode (f6c61cff) · Commits · 戴 / test

Documentation/hwmon/lm85

+7 −0

Original line number	Diff line number	Diff line
		@@ -101,6 +101,13 @@ Devices has confirmed this "bug". The ADT7463 is reported to work as
		described in the documentation. The current lm85 driver does not show the
		offset register.

		The ADT7468 has a high-frequency PWM mode, where all PWM outputs are
		driven by a 22.5 kHz clock. This is a global mode, not per-PWM output,
		which means that setting any PWM frequency above 11.3 kHz will switch
		all 3 PWM outputs to a 22.5 kHz frequency. Conversely, setting any PWM
		frequency below 11.3 kHz will switch all 3 PWM outputs to a frequency
		between 10 and 100 Hz, which can then be tuned separately.

		See the vendor datasheets for more information. There is application note
		from National (AN-1260) with some additional information about the LM85.
		The Analog Devices datasheet is very detailed and describes a procedure for

drivers/hwmon/lm85.c

+28 −7

Original line number	Diff line number	Diff line
		@@ -64,9 +64,12 @@ enum chips {
		#define LM85_REG_VERSTEP 0x3f

		#define ADT7468_REG_CFG5 0x7c
		#define ADT7468_OFF64 0x01
		#define ADT7468_OFF64 (1 << 0)
		#define ADT7468_HFPWM (1 << 1)
		#define IS_ADT7468_OFF64(data) \
		((data)->type == adt7468 && !((data)->cfg5 & ADT7468_OFF64))
		#define IS_ADT7468_HFPWM(data) \
		((data)->type == adt7468 && !((data)->cfg5 & ADT7468_HFPWM))

		/* These are the recognized values for the above regs */
		#define LM85_COMPANY_NATIONAL 0x01
		@@ -567,8 +570,14 @@ static ssize_t show_pwm_freq(struct device *dev,
		{
		int nr = to_sensor_dev_attr(attr)->index;
		struct lm85_data *data = lm85_update_device(dev);
		return sprintf(buf, "%d\n", FREQ_FROM_REG(data->freq_map,
		data->pwm_freq[nr]));
		int freq;

		if (IS_ADT7468_HFPWM(data))
		freq = 22500;
		else
		freq = FREQ_FROM_REG(data->freq_map, data->pwm_freq[nr]);

		return sprintf(buf, "%d\n", freq);
		}

		static ssize_t set_pwm_freq(struct device *dev,
		@@ -580,10 +589,22 @@ static ssize_t set_pwm_freq(struct device *dev,
		long val = simple_strtol(buf, NULL, 10);

		mutex_lock(&data->update_lock);
		/* The ADT7468 has a special high-frequency PWM output mode,
		* where all PWM outputs are driven by a 22.5 kHz clock.
		* This might confuse the user, but there's not much we can do. */
		if (data->type == adt7468 && val >= 11300) { /* High freq. mode */
		data->cfg5 &= ~ADT7468_HFPWM;
		lm85_write_value(client, ADT7468_REG_CFG5, data->cfg5);
		} else { /* Low freq. mode */
		data->pwm_freq[nr] = FREQ_TO_REG(data->freq_map, val);
		lm85_write_value(client, LM85_REG_AFAN_RANGE(nr),
		(data->zone[nr].range << 4)
		\| data->pwm_freq[nr]);
		if (data->type == adt7468) {
		data->cfg5 \|= ADT7468_HFPWM;
		lm85_write_value(client, ADT7468_REG_CFG5, data->cfg5);
		}
		}
		mutex_unlock(&data->update_lock);
		return count;
		}

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