// SPDX-License-Identifier: GPL-2.0 /* * Texas Instruments TSC2046 SPI ADC driver * * Copyright (c) 2021 Oleksij Rempel <[email protected]>, Pengutronix */ #include <linux/bitfield.h> #include <linux/delay.h> #include <linux/module.h> #include <linux/regulator/consumer.h> #include <linux/spi/spi.h> #include <linux/units.h> #include <asm/unaligned.h> #include <linux/iio/buffer.h> #include <linux/iio/trigger_consumer.h> #include <linux/iio/triggered_buffer.h> #include <linux/iio/trigger.h> /* * The PENIRQ of TSC2046 controller is implemented as level shifter attached to * the X+ line. If voltage of the X+ line reaches a specific level the IRQ will * be activated or deactivated. * To make this kind of IRQ reusable as trigger following additions were * implemented: * - rate limiting: * For typical touchscreen use case, we need to trigger about each 10ms. * - hrtimer: * Continue triggering at least once after the IRQ was deactivated. Then * deactivate this trigger to stop sampling in order to reduce power * consumption. */ #define TI_TSC2046_NAME … /* This driver doesn't aim at the peak continuous sample rate */ #define TI_TSC2046_MAX_SAMPLE_RATE … #define TI_TSC2046_SAMPLE_BITS … #define TI_TSC2046_MAX_CLK_FREQ … #define TI_TSC2046_SAMPLE_INTERVAL_US … #define TI_TSC2046_START … #define TI_TSC2046_ADDR … #define TI_TSC2046_ADDR_TEMP1 … #define TI_TSC2046_ADDR_AUX … #define TI_TSC2046_ADDR_X … #define TI_TSC2046_ADDR_Z2 … #define TI_TSC2046_ADDR_Z1 … #define TI_TSC2046_ADDR_VBAT … #define TI_TSC2046_ADDR_Y … #define TI_TSC2046_ADDR_TEMP0 … /* * The mode bit sets the resolution of the ADC. With this bit low, the next * conversion has 12-bit resolution, whereas with this bit high, the next * conversion has 8-bit resolution. This driver is optimized for 12-bit mode. * So, for this driver, this bit should stay zero. */ #define TI_TSC2046_8BIT_MODE … /* * SER/DFR - The SER/DFR bit controls the reference mode, either single-ended * (high) or differential (low). */ #define TI_TSC2046_SER … /* * If VREF_ON and ADC_ON are both zero, then the chip operates in * auto-wake/suspend mode. In most case this bits should stay zero. */ #define TI_TSC2046_PD1_VREF_ON … #define TI_TSC2046_PD0_ADC_ON … /* * All supported devices can do 8 or 12bit resolution. This driver * supports only 12bit mode, here we have a 16bit data transfer, where * the MSB and the 3 LSB are 0. */ #define TI_TSC2046_DATA_12BIT … #define TI_TSC2046_MAX_CHAN … #define TI_TSC2046_MIN_POLL_CNT … #define TI_TSC2046_EXT_POLL_CNT … #define TI_TSC2046_POLL_CNT … #define TI_TSC2046_INT_VREF … /* Represents a HW sample */ struct tsc2046_adc_atom { … } __packed; /* Layout of atomic buffers within big buffer */ struct tsc2046_adc_group_layout { … }; struct tsc2046_adc_dcfg { … }; struct tsc2046_adc_ch_cfg { … }; enum tsc2046_state { … }; struct tsc2046_adc_priv { … }; #define TI_TSC2046_V_CHAN(index, bits, name) … #define DECLARE_TI_TSC2046_8_CHANNELS(name, bits) … static DECLARE_TI_TSC2046_8_CHANNELS(tsc2046_adc, 12); static const struct tsc2046_adc_dcfg tsc2046_adc_dcfg_tsc2046e = …; /* * Convert time to a number of samples which can be transferred within this * time. */ static unsigned int tsc2046_adc_time_to_count(struct tsc2046_adc_priv *priv, unsigned long time) { … } static u8 tsc2046_adc_get_cmd(struct tsc2046_adc_priv *priv, int ch_idx, bool keep_power) { … } static u16 tsc2046_adc_get_value(struct tsc2046_adc_atom *buf) { … } static int tsc2046_adc_read_one(struct tsc2046_adc_priv *priv, int ch_idx, u32 *effective_speed_hz) { … } static size_t tsc2046_adc_group_set_layout(struct tsc2046_adc_priv *priv, unsigned int group, unsigned int ch_idx) { … } static void tsc2046_adc_group_set_cmd(struct tsc2046_adc_priv *priv, unsigned int group, int ch_idx) { … } static u16 tsc2046_adc_get_val(struct tsc2046_adc_priv *priv, int group) { … } static int tsc2046_adc_scan(struct iio_dev *indio_dev) { … } static irqreturn_t tsc2046_adc_trigger_handler(int irq, void *p) { … } static int tsc2046_adc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long m) { … } static int tsc2046_adc_update_scan_mode(struct iio_dev *indio_dev, const unsigned long *active_scan_mask) { … } static const struct iio_info tsc2046_adc_info = …; static enum hrtimer_restart tsc2046_adc_timer(struct hrtimer *hrtimer) { … } static irqreturn_t tsc2046_adc_irq(int irq, void *dev_id) { … } static void tsc2046_adc_reenable_trigger(struct iio_trigger *trig) { … } static int tsc2046_adc_set_trigger_state(struct iio_trigger *trig, bool enable) { … } static const struct iio_trigger_ops tsc2046_adc_trigger_ops = …; static int tsc2046_adc_setup_spi_msg(struct tsc2046_adc_priv *priv) { … } static void tsc2046_adc_parse_fwnode(struct tsc2046_adc_priv *priv) { … } static void tsc2046_adc_regulator_disable(void *data) { … } static int tsc2046_adc_configure_regulator(struct tsc2046_adc_priv *priv) { … } static int tsc2046_adc_probe(struct spi_device *spi) { … } static const struct of_device_id ads7950_of_table[] = …; MODULE_DEVICE_TABLE(of, ads7950_of_table); static const struct spi_device_id tsc2046_adc_spi_ids[] = …; MODULE_DEVICE_TABLE(spi, tsc2046_adc_spi_ids); static struct spi_driver tsc2046_adc_driver = …; module_spi_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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