// SPDX-License-Identifier: GPL-2.0+ /* * IIO driver for PAC1921 High-Side Power/Current Monitor * * Copyright (C) 2024 Matteo Martelli <[email protected]> */ #include <linux/unaligned.h> #include <linux/bitfield.h> #include <linux/i2c.h> #include <linux/iio/events.h> #include <linux/iio/iio.h> #include <linux/iio/trigger_consumer.h> #include <linux/iio/triggered_buffer.h> #include <linux/regmap.h> #include <linux/units.h> /* pac1921 registers */ #define PAC1921_REG_GAIN_CFG … #define PAC1921_REG_INT_CFG … #define PAC1921_REG_CONTROL … #define PAC1921_REG_VBUS … #define PAC1921_REG_VSENSE … #define PAC1921_REG_OVERFLOW_STS … #define PAC1921_REG_VPOWER … /* pac1921 gain configuration bits */ #define PAC1921_GAIN_DI_GAIN_MASK … #define PAC1921_GAIN_DV_GAIN_MASK … /* pac1921 integration configuration bits */ #define PAC1921_INT_CFG_SMPL_MASK … #define PAC1921_INT_CFG_VSFEN … #define PAC1921_INT_CFG_VBFEN … #define PAC1921_INT_CFG_RIOV … #define PAC1921_INT_CFG_INTEN … /* pac1921 control bits */ #define PAC1921_CONTROL_MXSL_MASK … enum pac1921_mxsl { … }; #define PAC1921_CONTROL_SLEEP … /* pac1921 result registers mask and resolution */ #define PAC1921_RES_MASK … #define PAC1921_RES_RESOLUTION … /* pac1921 overflow status bits */ #define PAC1921_OVERFLOW_VSOV … #define PAC1921_OVERFLOW_VBOV … #define PAC1921_OVERFLOW_VPOV … /* pac1921 constants */ #define PAC1921_MAX_VSENSE_MV … #define PAC1921_MAX_VBUS_V … /* Time to first communication after power up (tINT_T) */ #define PAC1921_POWERUP_TIME_MS … /* Time from Sleep State to Start of Integration Period (tSLEEP_TO_INT) */ #define PAC1921_SLEEP_TO_INT_TIME_US … /* pac1921 defaults */ #define PAC1921_DEFAULT_DV_GAIN … #define PAC1921_DEFAULT_DI_GAIN … #define PAC1921_DEFAULT_NUM_SAMPLES … /* * Pre-computed scale factors for BUS voltage * format: IIO_VAL_INT_PLUS_NANO * unit: mV * * Vbus scale (mV) = max_vbus (mV) / dv_gain / resolution */ static const int pac1921_vbus_scales[][2] = …; /* * Pre-computed scales for SENSE voltage * format: IIO_VAL_INT_PLUS_NANO * unit: mV * * Vsense scale (mV) = max_vsense (mV) / di_gain / resolution */ static const int pac1921_vsense_scales[][2] = …; /* * Numbers of samples used to integrate measurements at the end of an * integration period. * * Changing the number of samples affects the integration period: higher the * number of samples, longer the integration period. * * These correspond to the oversampling ratios available exposed to userspace. */ static const int pac1921_int_num_samples[] = …; /* * The integration period depends on the configuration of number of integration * samples, measurement resolution and post filters. The following array * contains integration periods, in microsecs unit, based on table 4-5 from * datasheet considering power integration mode, 14-Bit resolution and post * filters on. Each index corresponds to a specific number of samples from 1 * to 2048. */ static const unsigned int pac1921_int_periods_usecs[] = …; /* pac1921 regmap configuration */ static const struct regmap_range pac1921_regmap_wr_ranges[] = …; static const struct regmap_access_table pac1921_regmap_wr_table = …; static const struct regmap_range pac1921_regmap_rd_ranges[] = …; static const struct regmap_access_table pac1921_regmap_rd_table = …; static const struct regmap_config pac1921_regmap_config = …; enum pac1921_channels { … }; #define PAC1921_NUM_MEAS_CHANS … struct pac1921_priv { … }; /* * Check if first integration after configuration update has completed. * * Must be called with lock held. */ static bool pac1921_data_ready(struct pac1921_priv *priv) { … } static inline void pac1921_calc_scale(int dividend, int divisor, int *val, int *val2) { … } /* * Fill the table of scale factors for current * format: IIO_VAL_INT_PLUS_NANO * unit: mA * * Vsense LSB (nV) = max_vsense (nV) * di_gain / resolution * Current scale (mA) = Vsense LSB (nV) / shunt (uOhm) * * Must be called with held lock when updating after first initialization. */ static void pac1921_calc_current_scales(struct pac1921_priv *priv) { … } /* * Check if overflow occurred and if so, push the corresponding events. * * Must be called with lock held. */ static int pac1921_check_push_overflow(struct iio_dev *indio_dev, s64 timestamp) { … } /* * Read the value from a result register * * Result registers contain the most recent averaged values of Vbus, Vsense and * Vpower. Each value is 10 bits wide and spread across two consecutive 8 bit * registers, with 6 bit LSB zero padding. */ static int pac1921_read_res(struct pac1921_priv *priv, unsigned long reg, u16 *val) { … } static int pac1921_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { … } static int pac1921_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, const int **vals, int *type, int *length, long mask) { … } /* * Perform configuration update sequence: set the device into read state, then * write the config register and set the device back into integration state. * Also reset integration start time and mark first integration to be yet * completed. * * Must be called with lock held. */ static int pac1921_update_cfg_reg(struct pac1921_priv *priv, unsigned int reg, unsigned int mask, unsigned int val) { … } /* * Retrieve the index of the given scale (represented by scale_val and * scale_val2) from scales_tbl. The returned index (if found) is the log2 of * the gain corresponding to the given scale. * * Must be called with lock held if the scales_tbl can change runtime (e.g. for * the current scales table) */ static int pac1921_lookup_scale(const int (*const scales_tbl)[2], size_t size, int scale_val, int scale_val2) { … } /* * Configure device with the given gain (only if changed) * * Must be called with lock held. */ static int pac1921_update_gain(struct pac1921_priv *priv, u8 *priv_val, u8 gain, unsigned int mask) { … } /* * Given a scale factor represented by scale_val and scale_val2 with format * IIO_VAL_INT_PLUS_NANO, find the corresponding gain value and write it to the * device. * * Must be called with lock held. */ static int pac1921_update_gain_from_scale(struct pac1921_priv *priv, struct iio_chan_spec const *chan, int scale_val, int scale_val2) { … } /* * Retrieve the index of the given number of samples from the constant table. * The returned index (if found) is the log2 of the given num_samples. */ static int pac1921_lookup_int_num_samples(int num_samples) { … } /* * Update the device with the given number of integration samples. * * Must be called with lock held. */ static int pac1921_update_int_num_samples(struct pac1921_priv *priv, int num_samples) { … } static int pac1921_write_raw_get_fmt(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, long info) { … } static int pac1921_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { … } static int pac1921_read_label(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, char *label) { … } static int pac1921_read_event_config(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, enum iio_event_type type, enum iio_event_direction dir) { … } static int pac1921_write_event_config(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, enum iio_event_type type, enum iio_event_direction dir, int state) { … } static int pac1921_read_event_value(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, enum iio_event_type type, enum iio_event_direction dir, enum iio_event_info info, int *val, int *val2) { … } static const struct iio_info pac1921_iio = …; static ssize_t pac1921_read_shunt_resistor(struct iio_dev *indio_dev, uintptr_t private, const struct iio_chan_spec *chan, char *buf) { … } static ssize_t pac1921_write_shunt_resistor(struct iio_dev *indio_dev, uintptr_t private, const struct iio_chan_spec *chan, const char *buf, size_t len) { … } /* * Emit on sysfs the list of available scales contained in scales_tbl * * TODO:: this function can be replaced with iio_format_avail_list() if the * latter will ever be exported. * * Must be called with lock held if the scales_tbl can change runtime (e.g. for * the current scales table) */ static ssize_t pac1921_format_scale_avail(const int (*const scales_tbl)[2], size_t size, char *buf) { … } /* * Read available scales for a specific channel * * NOTE: using extended info insted of iio.read_avail() because access to * current scales must be locked as they depend on shunt resistor which may * change runtime. Caller of iio.read_avail() would access the table unlocked * instead. */ static ssize_t pac1921_read_scale_avail(struct iio_dev *indio_dev, uintptr_t private, const struct iio_chan_spec *chan, char *buf) { … } #define PAC1921_EXT_INFO_SCALE_AVAIL … static const struct iio_chan_spec_ext_info pac1921_ext_info_voltage[] = …; static const struct iio_chan_spec_ext_info pac1921_ext_info_current[] = …; static const struct iio_event_spec pac1921_overflow_event[] = …; static const struct iio_chan_spec pac1921_channels[] = …; static irqreturn_t pac1921_trigger_handler(int irq, void *p) { … } /* * Initialize device by writing initial configuration and putting it into * integration state. * * Must be called with lock held when called after first initialization * (e.g. from pm resume) */ static int pac1921_init(struct pac1921_priv *priv) { … } static int pac1921_suspend(struct device *dev) { … } static int pac1921_resume(struct device *dev) { … } static DEFINE_SIMPLE_DEV_PM_OPS(pac1921_pm_ops, pac1921_suspend, pac1921_resume); static void pac1921_regulator_disable(void *data) { … } static int pac1921_probe(struct i2c_client *client) { … } static const struct i2c_device_id pac1921_id[] = …; MODULE_DEVICE_TABLE(i2c, pac1921_id); static const struct of_device_id pac1921_of_match[] = …; MODULE_DEVICE_TABLE(of, pac1921_of_match); static struct i2c_driver pac1921_driver = …; module_i2c_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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