diff options
Diffstat (limited to 'drivers/iio/adc/at91-sama5d2_adc.c')
| -rw-r--r-- | drivers/iio/adc/at91-sama5d2_adc.c | 1995 |
1 files changed, 1995 insertions, 0 deletions
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c new file mode 100644 index 000000000..b806c1ab9 --- /dev/null +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -0,0 +1,1995 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Atmel ADC driver for SAMA5D2 devices and compatible. + * + * Copyright (C) 2015 Atmel, + * 2015 Ludovic Desroches <ludovic.desroches@atmel.com> + */ + +#include <linux/bitops.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/wait.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/buffer.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/pinctrl/consumer.h> +#include <linux/regulator/consumer.h> + +/* Control Register */ +#define AT91_SAMA5D2_CR 0x00 +/* Software Reset */ +#define AT91_SAMA5D2_CR_SWRST BIT(0) +/* Start Conversion */ +#define AT91_SAMA5D2_CR_START BIT(1) +/* Touchscreen Calibration */ +#define AT91_SAMA5D2_CR_TSCALIB BIT(2) +/* Comparison Restart */ +#define AT91_SAMA5D2_CR_CMPRST BIT(4) + +/* Mode Register */ +#define AT91_SAMA5D2_MR 0x04 +/* Trigger Selection */ +#define AT91_SAMA5D2_MR_TRGSEL(v) ((v) << 1) +/* ADTRG */ +#define AT91_SAMA5D2_MR_TRGSEL_TRIG0 0 +/* TIOA0 */ +#define AT91_SAMA5D2_MR_TRGSEL_TRIG1 1 +/* TIOA1 */ +#define AT91_SAMA5D2_MR_TRGSEL_TRIG2 2 +/* TIOA2 */ +#define AT91_SAMA5D2_MR_TRGSEL_TRIG3 3 +/* PWM event line 0 */ +#define AT91_SAMA5D2_MR_TRGSEL_TRIG4 4 +/* PWM event line 1 */ +#define AT91_SAMA5D2_MR_TRGSEL_TRIG5 5 +/* TIOA3 */ +#define AT91_SAMA5D2_MR_TRGSEL_TRIG6 6 +/* RTCOUT0 */ +#define AT91_SAMA5D2_MR_TRGSEL_TRIG7 7 +/* Sleep Mode */ +#define AT91_SAMA5D2_MR_SLEEP BIT(5) +/* Fast Wake Up */ +#define AT91_SAMA5D2_MR_FWUP BIT(6) +/* Prescaler Rate Selection */ +#define AT91_SAMA5D2_MR_PRESCAL(v) ((v) << AT91_SAMA5D2_MR_PRESCAL_OFFSET) +#define AT91_SAMA5D2_MR_PRESCAL_OFFSET 8 +#define AT91_SAMA5D2_MR_PRESCAL_MAX 0xff +#define AT91_SAMA5D2_MR_PRESCAL_MASK GENMASK(15, 8) +/* Startup Time */ +#define AT91_SAMA5D2_MR_STARTUP(v) ((v) << 16) +#define AT91_SAMA5D2_MR_STARTUP_MASK GENMASK(19, 16) +/* Analog Change */ +#define AT91_SAMA5D2_MR_ANACH BIT(23) +/* Tracking Time */ +#define AT91_SAMA5D2_MR_TRACKTIM(v) ((v) << 24) +#define AT91_SAMA5D2_MR_TRACKTIM_MAX 0xf +/* Transfer Time */ +#define AT91_SAMA5D2_MR_TRANSFER(v) ((v) << 28) +#define AT91_SAMA5D2_MR_TRANSFER_MAX 0x3 +/* Use Sequence Enable */ +#define AT91_SAMA5D2_MR_USEQ BIT(31) + +/* Channel Sequence Register 1 */ +#define AT91_SAMA5D2_SEQR1 0x08 +/* Channel Sequence Register 2 */ +#define AT91_SAMA5D2_SEQR2 0x0c +/* Channel Enable Register */ +#define AT91_SAMA5D2_CHER 0x10 +/* Channel Disable Register */ +#define AT91_SAMA5D2_CHDR 0x14 +/* Channel Status Register */ +#define AT91_SAMA5D2_CHSR 0x18 +/* Last Converted Data Register */ +#define AT91_SAMA5D2_LCDR 0x20 +/* Interrupt Enable Register */ +#define AT91_SAMA5D2_IER 0x24 +/* Interrupt Enable Register - TS X measurement ready */ +#define AT91_SAMA5D2_IER_XRDY BIT(20) +/* Interrupt Enable Register - TS Y measurement ready */ +#define AT91_SAMA5D2_IER_YRDY BIT(21) +/* Interrupt Enable Register - TS pressure measurement ready */ +#define AT91_SAMA5D2_IER_PRDY BIT(22) +/* Interrupt Enable Register - Data ready */ +#define AT91_SAMA5D2_IER_DRDY BIT(24) +/* Interrupt Enable Register - general overrun error */ +#define AT91_SAMA5D2_IER_GOVRE BIT(25) +/* Interrupt Enable Register - Pen detect */ +#define AT91_SAMA5D2_IER_PEN BIT(29) +/* Interrupt Enable Register - No pen detect */ +#define AT91_SAMA5D2_IER_NOPEN BIT(30) +/* Interrupt Disable Register */ +#define AT91_SAMA5D2_IDR 0x28 +/* Interrupt Mask Register */ +#define AT91_SAMA5D2_IMR 0x2c +/* Interrupt Status Register */ +#define AT91_SAMA5D2_ISR 0x30 +/* Interrupt Status Register - Pen touching sense status */ +#define AT91_SAMA5D2_ISR_PENS BIT(31) +/* Last Channel Trigger Mode Register */ +#define AT91_SAMA5D2_LCTMR 0x34 +/* Last Channel Compare Window Register */ +#define AT91_SAMA5D2_LCCWR 0x38 +/* Overrun Status Register */ +#define AT91_SAMA5D2_OVER 0x3c +/* Extended Mode Register */ +#define AT91_SAMA5D2_EMR 0x40 +/* Extended Mode Register - Oversampling rate */ +#define AT91_SAMA5D2_EMR_OSR(V) ((V) << 16) +#define AT91_SAMA5D2_EMR_OSR_MASK GENMASK(17, 16) +#define AT91_SAMA5D2_EMR_OSR_1SAMPLES 0 +#define AT91_SAMA5D2_EMR_OSR_4SAMPLES 1 +#define AT91_SAMA5D2_EMR_OSR_16SAMPLES 2 + +/* Extended Mode Register - Averaging on single trigger event */ +#define AT91_SAMA5D2_EMR_ASTE(V) ((V) << 20) +/* Compare Window Register */ +#define AT91_SAMA5D2_CWR 0x44 +/* Channel Gain Register */ +#define AT91_SAMA5D2_CGR 0x48 + +/* Channel Offset Register */ +#define AT91_SAMA5D2_COR 0x4c +#define AT91_SAMA5D2_COR_DIFF_OFFSET 16 + +/* Channel Data Register 0 */ +#define AT91_SAMA5D2_CDR0 0x50 +/* Analog Control Register */ +#define AT91_SAMA5D2_ACR 0x94 +/* Analog Control Register - Pen detect sensitivity mask */ +#define AT91_SAMA5D2_ACR_PENDETSENS_MASK GENMASK(1, 0) + +/* Touchscreen Mode Register */ +#define AT91_SAMA5D2_TSMR 0xb0 +/* Touchscreen Mode Register - No touch mode */ +#define AT91_SAMA5D2_TSMR_TSMODE_NONE 0 +/* Touchscreen Mode Register - 4 wire screen, no pressure measurement */ +#define AT91_SAMA5D2_TSMR_TSMODE_4WIRE_NO_PRESS 1 +/* Touchscreen Mode Register - 4 wire screen, pressure measurement */ +#define AT91_SAMA5D2_TSMR_TSMODE_4WIRE_PRESS 2 +/* Touchscreen Mode Register - 5 wire screen */ +#define AT91_SAMA5D2_TSMR_TSMODE_5WIRE 3 +/* Touchscreen Mode Register - Average samples mask */ +#define AT91_SAMA5D2_TSMR_TSAV_MASK GENMASK(5, 4) +/* Touchscreen Mode Register - Average samples */ +#define AT91_SAMA5D2_TSMR_TSAV(x) ((x) << 4) +/* Touchscreen Mode Register - Touch/trigger frequency ratio mask */ +#define AT91_SAMA5D2_TSMR_TSFREQ_MASK GENMASK(11, 8) +/* Touchscreen Mode Register - Touch/trigger frequency ratio */ +#define AT91_SAMA5D2_TSMR_TSFREQ(x) ((x) << 8) +/* Touchscreen Mode Register - Pen Debounce Time mask */ +#define AT91_SAMA5D2_TSMR_PENDBC_MASK GENMASK(31, 28) +/* Touchscreen Mode Register - Pen Debounce Time */ +#define AT91_SAMA5D2_TSMR_PENDBC(x) ((x) << 28) +/* Touchscreen Mode Register - No DMA for touch measurements */ +#define AT91_SAMA5D2_TSMR_NOTSDMA BIT(22) +/* Touchscreen Mode Register - Disable pen detection */ +#define AT91_SAMA5D2_TSMR_PENDET_DIS (0 << 24) +/* Touchscreen Mode Register - Enable pen detection */ +#define AT91_SAMA5D2_TSMR_PENDET_ENA BIT(24) + +/* Touchscreen X Position Register */ +#define AT91_SAMA5D2_XPOSR 0xb4 +/* Touchscreen Y Position Register */ +#define AT91_SAMA5D2_YPOSR 0xb8 +/* Touchscreen Pressure Register */ +#define AT91_SAMA5D2_PRESSR 0xbc +/* Trigger Register */ +#define AT91_SAMA5D2_TRGR 0xc0 +/* Mask for TRGMOD field of TRGR register */ +#define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0) +/* No trigger, only software trigger can start conversions */ +#define AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER 0 +/* Trigger Mode external trigger rising edge */ +#define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE 1 +/* Trigger Mode external trigger falling edge */ +#define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL 2 +/* Trigger Mode external trigger any edge */ +#define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY 3 +/* Trigger Mode internal periodic */ +#define AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC 5 +/* Trigger Mode - trigger period mask */ +#define AT91_SAMA5D2_TRGR_TRGPER_MASK GENMASK(31, 16) +/* Trigger Mode - trigger period */ +#define AT91_SAMA5D2_TRGR_TRGPER(x) ((x) << 16) + +/* Correction Select Register */ +#define AT91_SAMA5D2_COSR 0xd0 +/* Correction Value Register */ +#define AT91_SAMA5D2_CVR 0xd4 +/* Channel Error Correction Register */ +#define AT91_SAMA5D2_CECR 0xd8 +/* Write Protection Mode Register */ +#define AT91_SAMA5D2_WPMR 0xe4 +/* Write Protection Status Register */ +#define AT91_SAMA5D2_WPSR 0xe8 +/* Version Register */ +#define AT91_SAMA5D2_VERSION 0xfc + +#define AT91_SAMA5D2_HW_TRIG_CNT 3 +#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12 +#define AT91_SAMA5D2_DIFF_CHAN_CNT 6 + +#define AT91_SAMA5D2_TIMESTAMP_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \ + AT91_SAMA5D2_DIFF_CHAN_CNT + 1) + +#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \ + AT91_SAMA5D2_DIFF_CHAN_CNT * 2) +#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX (AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1) +#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX (AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1) +#define AT91_SAMA5D2_MAX_CHAN_IDX AT91_SAMA5D2_TOUCH_P_CHAN_IDX + +#define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US 2000 /* 2ms */ +#define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US 200 + +#define AT91_SAMA5D2_XYZ_MASK GENMASK(11, 0) + +#define AT91_SAMA5D2_MAX_POS_BITS 12 + +/* + * Maximum number of bytes to hold conversion from all channels + * without the timestamp. + */ +#define AT91_BUFFER_MAX_CONVERSION_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \ + AT91_SAMA5D2_DIFF_CHAN_CNT) * 2) + +/* This total must also include the timestamp */ +#define AT91_BUFFER_MAX_BYTES (AT91_BUFFER_MAX_CONVERSION_BYTES + 8) + +#define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2) + +#define AT91_HWFIFO_MAX_SIZE_STR "128" +#define AT91_HWFIFO_MAX_SIZE 128 + +/* Possible values for oversampling ratio */ +#define AT91_OSR_1SAMPLES 1 +#define AT91_OSR_4SAMPLES 4 +#define AT91_OSR_16SAMPLES 16 + +#define AT91_SAMA5D2_CHAN_SINGLE(num, addr) \ + { \ + .type = IIO_VOLTAGE, \ + .channel = num, \ + .address = addr, \ + .scan_index = num, \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 14, \ + .storagebits = 16, \ + }, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\ + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ + .datasheet_name = "CH"#num, \ + .indexed = 1, \ + } + +#define AT91_SAMA5D2_CHAN_DIFF(num, num2, addr) \ + { \ + .type = IIO_VOLTAGE, \ + .differential = 1, \ + .channel = num, \ + .channel2 = num2, \ + .address = addr, \ + .scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT, \ + .scan_type = { \ + .sign = 's', \ + .realbits = 14, \ + .storagebits = 16, \ + }, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\ + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ + .datasheet_name = "CH"#num"-CH"#num2, \ + .indexed = 1, \ + } + +#define AT91_SAMA5D2_CHAN_TOUCH(num, name, mod) \ + { \ + .type = IIO_POSITIONRELATIVE, \ + .modified = 1, \ + .channel = num, \ + .channel2 = mod, \ + .scan_index = num, \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 12, \ + .storagebits = 16, \ + }, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\ + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ + .datasheet_name = name, \ + } +#define AT91_SAMA5D2_CHAN_PRESSURE(num, name) \ + { \ + .type = IIO_PRESSURE, \ + .channel = num, \ + .scan_index = num, \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 12, \ + .storagebits = 16, \ + }, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\ + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ + .datasheet_name = name, \ + } + +#define at91_adc_readl(st, reg) readl_relaxed(st->base + reg) +#define at91_adc_writel(st, reg, val) writel_relaxed(val, st->base + reg) + +struct at91_adc_soc_info { + unsigned startup_time; + unsigned min_sample_rate; + unsigned max_sample_rate; +}; + +struct at91_adc_trigger { + char *name; + unsigned int trgmod_value; + unsigned int edge_type; + bool hw_trig; +}; + +/** + * struct at91_adc_dma - at91-sama5d2 dma information struct + * @dma_chan: the dma channel acquired + * @rx_buf: dma coherent allocated area + * @rx_dma_buf: dma handler for the buffer + * @phys_addr: physical address of the ADC base register + * @buf_idx: index inside the dma buffer where reading was last done + * @rx_buf_sz: size of buffer used by DMA operation + * @watermark: number of conversions to copy before DMA triggers irq + * @dma_ts: hold the start timestamp of dma operation + */ +struct at91_adc_dma { + struct dma_chan *dma_chan; + u8 *rx_buf; + dma_addr_t rx_dma_buf; + phys_addr_t phys_addr; + int buf_idx; + int rx_buf_sz; + int watermark; + s64 dma_ts; +}; + +/** + * struct at91_adc_touch - at91-sama5d2 touchscreen information struct + * @sample_period_val: the value for periodic trigger interval + * @touching: is the pen touching the screen or not + * @x_pos: temporary placeholder for pressure computation + * @channels_bitmask: bitmask with the touchscreen channels enabled + * @workq: workqueue for buffer data pushing + */ +struct at91_adc_touch { + u16 sample_period_val; + bool touching; + u16 x_pos; + unsigned long channels_bitmask; + struct work_struct workq; +}; + +struct at91_adc_state { + void __iomem *base; + int irq; + struct clk *per_clk; + struct regulator *reg; + struct regulator *vref; + int vref_uv; + unsigned int current_sample_rate; + struct iio_trigger *trig; + const struct at91_adc_trigger *selected_trig; + const struct iio_chan_spec *chan; + bool conversion_done; + u32 conversion_value; + unsigned int oversampling_ratio; + struct at91_adc_soc_info soc_info; + wait_queue_head_t wq_data_available; + struct at91_adc_dma dma_st; + struct at91_adc_touch touch_st; + struct iio_dev *indio_dev; + /* Ensure naturally aligned timestamp */ + u16 buffer[AT91_BUFFER_MAX_HWORDS] __aligned(8); + /* + * lock to prevent concurrent 'single conversion' requests through + * sysfs. + */ + struct mutex lock; +}; + +static const struct at91_adc_trigger at91_adc_trigger_list[] = { + { + .name = "external_rising", + .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE, + .edge_type = IRQ_TYPE_EDGE_RISING, + .hw_trig = true, + }, + { + .name = "external_falling", + .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL, + .edge_type = IRQ_TYPE_EDGE_FALLING, + .hw_trig = true, + }, + { + .name = "external_any", + .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY, + .edge_type = IRQ_TYPE_EDGE_BOTH, + .hw_trig = true, + }, + { + .name = "software", + .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER, + .edge_type = IRQ_TYPE_NONE, + .hw_trig = false, + }, +}; + +static const struct iio_chan_spec at91_adc_channels[] = { + AT91_SAMA5D2_CHAN_SINGLE(0, 0x50), + AT91_SAMA5D2_CHAN_SINGLE(1, 0x54), + AT91_SAMA5D2_CHAN_SINGLE(2, 0x58), + AT91_SAMA5D2_CHAN_SINGLE(3, 0x5c), + AT91_SAMA5D2_CHAN_SINGLE(4, 0x60), + AT91_SAMA5D2_CHAN_SINGLE(5, 0x64), + AT91_SAMA5D2_CHAN_SINGLE(6, 0x68), + AT91_SAMA5D2_CHAN_SINGLE(7, 0x6c), + AT91_SAMA5D2_CHAN_SINGLE(8, 0x70), + AT91_SAMA5D2_CHAN_SINGLE(9, 0x74), + AT91_SAMA5D2_CHAN_SINGLE(10, 0x78), + AT91_SAMA5D2_CHAN_SINGLE(11, 0x7c), + AT91_SAMA5D2_CHAN_DIFF(0, 1, 0x50), + AT91_SAMA5D2_CHAN_DIFF(2, 3, 0x58), + AT91_SAMA5D2_CHAN_DIFF(4, 5, 0x60), + AT91_SAMA5D2_CHAN_DIFF(6, 7, 0x68), + AT91_SAMA5D2_CHAN_DIFF(8, 9, 0x70), + AT91_SAMA5D2_CHAN_DIFF(10, 11, 0x78), + IIO_CHAN_SOFT_TIMESTAMP(AT91_SAMA5D2_TIMESTAMP_CHAN_IDX), + AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_X_CHAN_IDX, "x", IIO_MOD_X), + AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, "y", IIO_MOD_Y), + AT91_SAMA5D2_CHAN_PRESSURE(AT91_SAMA5D2_TOUCH_P_CHAN_IDX, "pressure"), +}; + +static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan) +{ + int i; + + for (i = 0; i < indio_dev->num_channels; i++) { + if (indio_dev->channels[i].scan_index == chan) + return i; + } + return -EINVAL; +} + +static inline struct iio_chan_spec const * +at91_adc_chan_get(struct iio_dev *indio_dev, int chan) +{ + int index = at91_adc_chan_xlate(indio_dev, chan); + + if (index < 0) + return NULL; + return indio_dev->channels + index; +} + +static inline int at91_adc_of_xlate(struct iio_dev *indio_dev, + const struct of_phandle_args *iiospec) +{ + return at91_adc_chan_xlate(indio_dev, iiospec->args[0]); +} + +static unsigned int at91_adc_active_scan_mask_to_reg(struct iio_dev *indio_dev) +{ + u32 mask = 0; + u8 bit; + + for_each_set_bit(bit, indio_dev->active_scan_mask, + indio_dev->num_channels) { + struct iio_chan_spec const *chan = + at91_adc_chan_get(indio_dev, bit); + mask |= BIT(chan->channel); + } + + return mask & GENMASK(11, 0); +} + +static void at91_adc_config_emr(struct at91_adc_state *st) +{ + /* configure the extended mode register */ + unsigned int emr = at91_adc_readl(st, AT91_SAMA5D2_EMR); + + /* select oversampling per single trigger event */ + emr |= AT91_SAMA5D2_EMR_ASTE(1); + + /* delete leftover content if it's the case */ + emr &= ~AT91_SAMA5D2_EMR_OSR_MASK; + + /* select oversampling ratio from configuration */ + switch (st->oversampling_ratio) { + case AT91_OSR_1SAMPLES: + emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_1SAMPLES) & + AT91_SAMA5D2_EMR_OSR_MASK; + break; + case AT91_OSR_4SAMPLES: + emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_4SAMPLES) & + AT91_SAMA5D2_EMR_OSR_MASK; + break; + case AT91_OSR_16SAMPLES: + emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_16SAMPLES) & + AT91_SAMA5D2_EMR_OSR_MASK; + break; + } + + at91_adc_writel(st, AT91_SAMA5D2_EMR, emr); +} + +static int at91_adc_adjust_val_osr(struct at91_adc_state *st, int *val) +{ + if (st->oversampling_ratio == AT91_OSR_1SAMPLES) { + /* + * in this case we only have 12 bits of real data, but channel + * is registered as 14 bits, so shift left two bits + */ + *val <<= 2; + } else if (st->oversampling_ratio == AT91_OSR_4SAMPLES) { + /* + * in this case we have 13 bits of real data, but channel + * is registered as 14 bits, so left shift one bit + */ + *val <<= 1; + } + + return IIO_VAL_INT; +} + +static void at91_adc_adjust_val_osr_array(struct at91_adc_state *st, void *buf, + int len) +{ + int i = 0, val; + u16 *buf_u16 = (u16 *) buf; + + /* + * We are converting each two bytes (each sample). + * First convert the byte based array to u16, and convert each sample + * separately. + * Each value is two bytes in an array of chars, so to not shift + * more than we need, save the value separately. + * len is in bytes, so divide by two to get number of samples. + */ + while (i < len / 2) { + val = buf_u16[i]; + at91_adc_adjust_val_osr(st, &val); + buf_u16[i] = val; + i++; + } +} + +static int at91_adc_configure_touch(struct at91_adc_state *st, bool state) +{ + u32 clk_khz = st->current_sample_rate / 1000; + int i = 0; + u16 pendbc; + u32 tsmr, acr; + + if (!state) { + /* disabling touch IRQs and setting mode to no touch enabled */ + at91_adc_writel(st, AT91_SAMA5D2_IDR, + AT91_SAMA5D2_IER_PEN | AT91_SAMA5D2_IER_NOPEN); + at91_adc_writel(st, AT91_SAMA5D2_TSMR, 0); + return 0; + } + /* + * debounce time is in microseconds, we need it in milliseconds to + * multiply with kilohertz, so, divide by 1000, but after the multiply. + * round up to make sure pendbc is at least 1 + */ + pendbc = round_up(AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US * + clk_khz / 1000, 1); + + /* get the required exponent */ + while (pendbc >> i++) + ; + + pendbc = i; + + tsmr = AT91_SAMA5D2_TSMR_TSMODE_4WIRE_PRESS; + + tsmr |= AT91_SAMA5D2_TSMR_TSAV(2) & AT91_SAMA5D2_TSMR_TSAV_MASK; + tsmr |= AT91_SAMA5D2_TSMR_PENDBC(pendbc) & + AT91_SAMA5D2_TSMR_PENDBC_MASK; + tsmr |= AT91_SAMA5D2_TSMR_NOTSDMA; + tsmr |= AT91_SAMA5D2_TSMR_PENDET_ENA; + tsmr |= AT91_SAMA5D2_TSMR_TSFREQ(2) & AT91_SAMA5D2_TSMR_TSFREQ_MASK; + + at91_adc_writel(st, AT91_SAMA5D2_TSMR, tsmr); + + acr = at91_adc_readl(st, AT91_SAMA5D2_ACR); + acr &= ~AT91_SAMA5D2_ACR_PENDETSENS_MASK; + acr |= 0x02 & AT91_SAMA5D2_ACR_PENDETSENS_MASK; + at91_adc_writel(st, AT91_SAMA5D2_ACR, acr); + + /* Sample Period Time = (TRGPER + 1) / ADCClock */ + st->touch_st.sample_period_val = + round_up((AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US * + clk_khz / 1000) - 1, 1); + /* enable pen detect IRQ */ + at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_PEN); + + return 0; +} + +static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg) +{ + u32 val; + u32 scale, result, pos; + + /* + * to obtain the actual position we must divide by scale + * and multiply with max, where + * max = 2^AT91_SAMA5D2_MAX_POS_BITS - 1 + */ + /* first half of register is the x or y, second half is the scale */ + val = at91_adc_readl(st, reg); + if (!val) + dev_dbg(&st->indio_dev->dev, "pos is 0\n"); + + pos = val & AT91_SAMA5D2_XYZ_MASK; + result = (pos << AT91_SAMA5D2_MAX_POS_BITS) - pos; + scale = (val >> 16) & AT91_SAMA5D2_XYZ_MASK; + if (scale == 0) { + dev_err(&st->indio_dev->dev, "scale is 0\n"); + return 0; + } + result /= scale; + + return result; +} + +static u16 at91_adc_touch_x_pos(struct at91_adc_state *st) +{ + st->touch_st.x_pos = at91_adc_touch_pos(st, AT91_SAMA5D2_XPOSR); + return st->touch_st.x_pos; +} + +static u16 at91_adc_touch_y_pos(struct at91_adc_state *st) +{ + return at91_adc_touch_pos(st, AT91_SAMA5D2_YPOSR); +} + +static u16 at91_adc_touch_pressure(struct at91_adc_state *st) +{ + u32 val; + u32 z1, z2; + u32 pres; + u32 rxp = 1; + u32 factor = 1000; + + /* calculate the pressure */ + val = at91_adc_readl(st, AT91_SAMA5D2_PRESSR); + z1 = val & AT91_SAMA5D2_XYZ_MASK; + z2 = (val >> 16) & AT91_SAMA5D2_XYZ_MASK; + + if (z1 != 0) + pres = rxp * (st->touch_st.x_pos * factor / 1024) * + (z2 * factor / z1 - factor) / + factor; + else + pres = 0xFFFF; /* no pen contact */ + + /* + * The pressure from device grows down, minimum is 0xFFFF, maximum 0x0. + * We compute it this way, but let's return it in the expected way, + * growing from 0 to 0xFFFF. + */ + return 0xFFFF - pres; +} + +static int at91_adc_read_position(struct at91_adc_state *st, int chan, u16 *val) +{ + *val = 0; + if (!st->touch_st.touching) + return -ENODATA; + if (chan == AT91_SAMA5D2_TOUCH_X_CHAN_IDX) + *val = at91_adc_touch_x_pos(st); + else if (chan == AT91_SAMA5D2_TOUCH_Y_CHAN_IDX) + *val = at91_adc_touch_y_pos(st); + else + return -ENODATA; + + return IIO_VAL_INT; +} + +static int at91_adc_read_pressure(struct at91_adc_state *st, int chan, u16 *val) +{ + *val = 0; + if (!st->touch_st.touching) + return -ENODATA; + if (chan == AT91_SAMA5D2_TOUCH_P_CHAN_IDX) + *val = at91_adc_touch_pressure(st); + else + return -ENODATA; + + return IIO_VAL_INT; +} + +static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state) +{ + struct iio_dev *indio = iio_trigger_get_drvdata(trig); + struct at91_adc_state *st = iio_priv(indio); + u32 status = at91_adc_readl(st, AT91_SAMA5D2_TRGR); + + /* clear TRGMOD */ + status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK; + + if (state) + status |= st->selected_trig->trgmod_value; + + /* set/unset hw trigger */ + at91_adc_writel(st, AT91_SAMA5D2_TRGR, status); + + return 0; +} + +static int at91_adc_reenable_trigger(struct iio_trigger *trig) +{ + struct iio_dev *indio = iio_trigger_get_drvdata(trig); + struct at91_adc_state *st = iio_priv(indio); + + /* if we are using DMA, we must not reenable irq after each trigger */ + if (st->dma_st.dma_chan) + return 0; + + enable_irq(st->irq); + + /* Needed to ACK the DRDY interruption */ + at91_adc_readl(st, AT91_SAMA5D2_LCDR); + + return 0; +} + +static const struct iio_trigger_ops at91_adc_trigger_ops = { + .set_trigger_state = &at91_adc_configure_trigger, + .try_reenable = &at91_adc_reenable_trigger, + .validate_device = iio_trigger_validate_own_device, +}; + +static int at91_adc_dma_size_done(struct at91_adc_state *st) +{ + struct dma_tx_state state; + enum dma_status status; + int i, size; + + status = dmaengine_tx_status(st->dma_st.dma_chan, + st->dma_st.dma_chan->cookie, + &state); + if (status != DMA_IN_PROGRESS) + return 0; + + /* Transferred length is size in bytes from end of buffer */ + i = st->dma_st.rx_buf_sz - state.residue; + + /* Return available bytes */ + if (i >= st->dma_st.buf_idx) + size = i - st->dma_st.buf_idx; + else + size = st->dma_st.rx_buf_sz + i - st->dma_st.buf_idx; + return size; +} + +static void at91_dma_buffer_done(void *data) +{ + struct iio_dev *indio_dev = data; + + iio_trigger_poll_chained(indio_dev->trig); +} + +static int at91_adc_dma_start(struct iio_dev *indio_dev) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + struct dma_async_tx_descriptor *desc; + dma_cookie_t cookie; + int ret; + u8 bit; + + if (!st->dma_st.dma_chan) + return 0; + + /* we start a new DMA, so set buffer index to start */ + st->dma_st.buf_idx = 0; + + /* + * compute buffer size w.r.t. watermark and enabled channels. + * scan_bytes is aligned so we need an exact size for DMA + */ + st->dma_st.rx_buf_sz = 0; + + for_each_set_bit(bit, indio_dev->active_scan_mask, + indio_dev->num_channels) { + struct iio_chan_spec const *chan = + at91_adc_chan_get(indio_dev, bit); + + if (!chan) + continue; + + st->dma_st.rx_buf_sz += chan->scan_type.storagebits / 8; + } + st->dma_st.rx_buf_sz *= st->dma_st.watermark; + + /* Prepare a DMA cyclic transaction */ + desc = dmaengine_prep_dma_cyclic(st->dma_st.dma_chan, + st->dma_st.rx_dma_buf, + st->dma_st.rx_buf_sz, + st->dma_st.rx_buf_sz / 2, + DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); + + if (!desc) { + dev_err(&indio_dev->dev, "cannot prepare DMA cyclic\n"); + return -EBUSY; + } + + desc->callback = at91_dma_buffer_done; + desc->callback_param = indio_dev; + + cookie = dmaengine_submit(desc); + ret = dma_submit_error(cookie); + if (ret) { + dev_err(&indio_dev->dev, "cannot submit DMA cyclic\n"); + dmaengine_terminate_async(st->dma_st.dma_chan); + return ret; + } + + /* enable general overrun error signaling */ + at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_GOVRE); + /* Issue pending DMA requests */ + dma_async_issue_pending(st->dma_st.dma_chan); + + /* consider current time as DMA start time for timestamps */ + st->dma_st.dma_ts = iio_get_time_ns(indio_dev); + + dev_dbg(&indio_dev->dev, "DMA cyclic started\n"); + + return 0; +} + +static bool at91_adc_buffer_check_use_irq(struct iio_dev *indio, + struct at91_adc_state *st) +{ + /* if using DMA, we do not use our own IRQ (we use DMA-controller) */ + if (st->dma_st.dma_chan) + return false; + /* if the trigger is not ours, then it has its own IRQ */ + if (iio_trigger_validate_own_device(indio->trig, indio)) + return false; + return true; +} + +static bool at91_adc_current_chan_is_touch(struct iio_dev *indio_dev) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + + return !!bitmap_subset(indio_dev->active_scan_mask, + &st->touch_st.channels_bitmask, + AT91_SAMA5D2_MAX_CHAN_IDX + 1); +} + +static int at91_adc_buffer_prepare(struct iio_dev *indio_dev) +{ + int ret; + u8 bit; + struct at91_adc_state *st = iio_priv(indio_dev); + + /* check if we are enabling triggered buffer or the touchscreen */ + if (at91_adc_current_chan_is_touch(indio_dev)) + return at91_adc_configure_touch(st, true); + + /* if we are not in triggered mode, we cannot enable the buffer. */ + if (!(indio_dev->currentmode & INDIO_ALL_TRIGGERED_MODES)) + return -EINVAL; + + /* we continue with the triggered buffer */ + ret = at91_adc_dma_start(indio_dev); + if (ret) { + dev_err(&indio_dev->dev, "buffer prepare failed\n"); + return ret; + } + + for_each_set_bit(bit, indio_dev->active_scan_mask, + indio_dev->num_channels) { + struct iio_chan_spec const *chan = + at91_adc_chan_get(indio_dev, bit); + u32 cor; + + if (!chan) + continue; + /* these channel types cannot be handled by this trigger */ + if (chan->type == IIO_POSITIONRELATIVE || + chan->type == IIO_PRESSURE) + continue; + + cor = at91_adc_readl(st, AT91_SAMA5D2_COR); + + if (chan->differential) + cor |= (BIT(chan->channel) | BIT(chan->channel2)) << + AT91_SAMA5D2_COR_DIFF_OFFSET; + else + cor &= ~(BIT(chan->channel) << + AT91_SAMA5D2_COR_DIFF_OFFSET); + + at91_adc_writel(st, AT91_SAMA5D2_COR, cor); + + at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel)); + } + + if (at91_adc_buffer_check_use_irq(indio_dev, st)) + at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_DRDY); + + return 0; +} + +static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + u8 bit; + + /* check if we are disabling triggered buffer or the touchscreen */ + if (at91_adc_current_chan_is_touch(indio_dev)) + return at91_adc_configure_touch(st, false); + + /* if we are not in triggered mode, nothing to do here */ + if (!(indio_dev->currentmode & INDIO_ALL_TRIGGERED_MODES)) + return -EINVAL; + + /* + * For each enable channel we must disable it in hardware. + * In the case of DMA, we must read the last converted value + * to clear EOC status and not get a possible interrupt later. + * This value is being read by DMA from LCDR anyway, so it's not lost. + */ + for_each_set_bit(bit, indio_dev->active_scan_mask, + indio_dev->num_channels) { + struct iio_chan_spec const *chan = + at91_adc_chan_get(indio_dev, bit); + + if (!chan) + continue; + /* these channel types are virtual, no need to do anything */ + if (chan->type == IIO_POSITIONRELATIVE || + chan->type == IIO_PRESSURE) + continue; + + at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel)); + + if (st->dma_st.dma_chan) + at91_adc_readl(st, chan->address); + } + + if (at91_adc_buffer_check_use_irq(indio_dev, st)) + at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_DRDY); + + /* read overflow register to clear possible overflow status */ + at91_adc_readl(st, AT91_SAMA5D2_OVER); + + /* if we are using DMA we must clear registers and end DMA */ + if (st->dma_st.dma_chan) + dmaengine_terminate_sync(st->dma_st.dma_chan); + + return 0; +} + +static const struct iio_buffer_setup_ops at91_buffer_setup_ops = { + .postdisable = &at91_adc_buffer_postdisable, +}; + +static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *indio, + char *trigger_name) +{ + struct iio_trigger *trig; + int ret; + + trig = devm_iio_trigger_alloc(&indio->dev, "%s-dev%d-%s", indio->name, + indio->id, trigger_name); + if (!trig) + return ERR_PTR(-ENOMEM); + + trig->dev.parent = indio->dev.parent; + iio_trigger_set_drvdata(trig, indio); + trig->ops = &at91_adc_trigger_ops; + + ret = devm_iio_trigger_register(&indio->dev, trig); + if (ret) + return ERR_PTR(ret); + + return trig; +} + +static int at91_adc_trigger_init(struct iio_dev *indio) +{ + struct at91_adc_state *st = iio_priv(indio); + + st->trig = at91_adc_allocate_trigger(indio, st->selected_trig->name); + if (IS_ERR(st->trig)) { + dev_err(&indio->dev, + "could not allocate trigger\n"); + return PTR_ERR(st->trig); + } + + return 0; +} + +static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev, + struct iio_poll_func *pf) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + int i = 0; + int val; + u8 bit; + u32 mask = at91_adc_active_scan_mask_to_reg(indio_dev); + unsigned int timeout = 50; + + /* + * Check if the conversion is ready. If not, wait a little bit, and + * in case of timeout exit with an error. + */ + while ((at91_adc_readl(st, AT91_SAMA5D2_ISR) & mask) != mask && + timeout) { + usleep_range(50, 100); + timeout--; + } + + /* Cannot read data, not ready. Continue without reporting data */ + if (!timeout) + return; + + for_each_set_bit(bit, indio_dev->active_scan_mask, + indio_dev->num_channels) { + struct iio_chan_spec const *chan = + at91_adc_chan_get(indio_dev, bit); + + if (!chan) + continue; + /* + * Our external trigger only supports the voltage channels. + * In case someone requested a different type of channel + * just put zeroes to buffer. + * This should not happen because we check the scan mode + * and scan mask when we enable the buffer, and we don't allow + * the buffer to start with a mixed mask (voltage and something + * else). + * Thus, emit a warning. + */ + if (chan->type == IIO_VOLTAGE) { + val = at91_adc_readl(st, chan->address); + at91_adc_adjust_val_osr(st, &val); + st->buffer[i] = val; + } else { + st->buffer[i] = 0; + WARN(true, "This trigger cannot handle this type of channel"); + } + i++; + } + iio_push_to_buffers_with_timestamp(indio_dev, st->buffer, + pf->timestamp); +} + +static void at91_adc_trigger_handler_dma(struct iio_dev *indio_dev) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + int transferred_len = at91_adc_dma_size_done(st); + s64 ns = iio_get_time_ns(indio_dev); + s64 interval; + int sample_index = 0, sample_count, sample_size; + + u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR); + /* if we reached this point, we cannot sample faster */ + if (status & AT91_SAMA5D2_IER_GOVRE) + pr_info_ratelimited("%s: conversion overrun detected\n", + indio_dev->name); + + sample_size = div_s64(st->dma_st.rx_buf_sz, st->dma_st.watermark); + + sample_count = div_s64(transferred_len, sample_size); + + /* + * interval between samples is total time since last transfer handling + * divided by the number of samples (total size divided by sample size) + */ + interval = div_s64((ns - st->dma_st.dma_ts), sample_count); + + while (transferred_len >= sample_size) { + /* + * for all the values in the current sample, + * adjust the values inside the buffer for oversampling + */ + at91_adc_adjust_val_osr_array(st, + &st->dma_st.rx_buf[st->dma_st.buf_idx], + sample_size); + + iio_push_to_buffers_with_timestamp(indio_dev, + (st->dma_st.rx_buf + st->dma_st.buf_idx), + (st->dma_st.dma_ts + interval * sample_index)); + /* adjust remaining length */ + transferred_len -= sample_size; + /* adjust buffer index */ + st->dma_st.buf_idx += sample_size; + /* in case of reaching end of buffer, reset index */ + if (st->dma_st.buf_idx >= st->dma_st.rx_buf_sz) + st->dma_st.buf_idx = 0; + sample_index++; + } + /* adjust saved time for next transfer handling */ + st->dma_st.dma_ts = iio_get_time_ns(indio_dev); +} + +static irqreturn_t at91_adc_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct at91_adc_state *st = iio_priv(indio_dev); + + /* + * If it's not our trigger, start a conversion now, as we are + * actually polling the trigger now. + */ + if (iio_trigger_validate_own_device(indio_dev->trig, indio_dev)) + at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_START); + + if (st->dma_st.dma_chan) + at91_adc_trigger_handler_dma(indio_dev); + else + at91_adc_trigger_handler_nodma(indio_dev, pf); + + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static int at91_adc_buffer_init(struct iio_dev *indio) +{ + return devm_iio_triggered_buffer_setup(&indio->dev, indio, + &iio_pollfunc_store_time, + &at91_adc_trigger_handler, &at91_buffer_setup_ops); +} + +static unsigned at91_adc_startup_time(unsigned startup_time_min, + unsigned adc_clk_khz) +{ + static const unsigned int startup_lookup[] = { + 0, 8, 16, 24, + 64, 80, 96, 112, + 512, 576, 640, 704, + 768, 832, 896, 960 + }; + unsigned ticks_min, i; + + /* + * Since the adc frequency is checked before, there is no reason + * to not meet the startup time constraint. + */ + + ticks_min = startup_time_min * adc_clk_khz / 1000; + for (i = 0; i < ARRAY_SIZE(startup_lookup); i++) + if (startup_lookup[i] > ticks_min) + break; + + return i; +} + +static void at91_adc_setup_samp_freq(struct iio_dev *indio_dev, unsigned freq) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + unsigned f_per, prescal, startup, mr; + + f_per = clk_get_rate(st->per_clk); + prescal = (f_per / (2 * freq)) - 1; + + startup = at91_adc_startup_time(st->soc_info.startup_time, + freq / 1000); + + mr = at91_adc_readl(st, AT91_SAMA5D2_MR); + mr &= ~(AT91_SAMA5D2_MR_STARTUP_MASK | AT91_SAMA5D2_MR_PRESCAL_MASK); + mr |= AT91_SAMA5D2_MR_STARTUP(startup); + mr |= AT91_SAMA5D2_MR_PRESCAL(prescal); + at91_adc_writel(st, AT91_SAMA5D2_MR, mr); + + dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u\n", + freq, startup, prescal); + st->current_sample_rate = freq; +} + +static inline unsigned at91_adc_get_sample_freq(struct at91_adc_state *st) +{ + return st->current_sample_rate; +} + +static void at91_adc_touch_data_handler(struct iio_dev *indio_dev) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + u8 bit; + u16 val; + int i = 0; + + for_each_set_bit(bit, indio_dev->active_scan_mask, + AT91_SAMA5D2_MAX_CHAN_IDX + 1) { + struct iio_chan_spec const *chan = + at91_adc_chan_get(indio_dev, bit); + + if (chan->type == IIO_POSITIONRELATIVE) + at91_adc_read_position(st, chan->channel, &val); + else if (chan->type == IIO_PRESSURE) + at91_adc_read_pressure(st, chan->channel, &val); + else + continue; + st->buffer[i] = val; + i++; + } + /* + * Schedule work to push to buffers. + * This is intended to push to the callback buffer that another driver + * registered. We are still in a handler from our IRQ. If we push + * directly, it means the other driver has it's callback called + * from our IRQ context. Which is something we better avoid. + * Let's schedule it after our IRQ is completed. + */ + schedule_work(&st->touch_st.workq); +} + +static void at91_adc_pen_detect_interrupt(struct at91_adc_state *st) +{ + at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_PEN); + at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_NOPEN | + AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY | + AT91_SAMA5D2_IER_PRDY); + at91_adc_writel(st, AT91_SAMA5D2_TRGR, + AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC | + AT91_SAMA5D2_TRGR_TRGPER(st->touch_st.sample_period_val)); + st->touch_st.touching = true; +} + +static void at91_adc_no_pen_detect_interrupt(struct iio_dev *indio_dev) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + + at91_adc_writel(st, AT91_SAMA5D2_TRGR, + AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER); + at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_NOPEN | + AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY | + AT91_SAMA5D2_IER_PRDY); + st->touch_st.touching = false; + + at91_adc_touch_data_handler(indio_dev); + + at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_PEN); +} + +static void at91_adc_workq_handler(struct work_struct *workq) +{ + struct at91_adc_touch *touch_st = container_of(workq, + struct at91_adc_touch, workq); + struct at91_adc_state *st = container_of(touch_st, + struct at91_adc_state, touch_st); + struct iio_dev *indio_dev = st->indio_dev; + + iio_push_to_buffers(indio_dev, st->buffer); +} + +static irqreturn_t at91_adc_interrupt(int irq, void *private) +{ + struct iio_dev *indio = private; + struct at91_adc_state *st = iio_priv(indio); + u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR); + u32 imr = at91_adc_readl(st, AT91_SAMA5D2_IMR); + u32 rdy_mask = AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY | + AT91_SAMA5D2_IER_PRDY; + + if (!(status & imr)) + return IRQ_NONE; + if (status & AT91_SAMA5D2_IER_PEN) { + /* pen detected IRQ */ + at91_adc_pen_detect_interrupt(st); + } else if ((status & AT91_SAMA5D2_IER_NOPEN)) { + /* nopen detected IRQ */ + at91_adc_no_pen_detect_interrupt(indio); + } else if ((status & AT91_SAMA5D2_ISR_PENS) && + ((status & rdy_mask) == rdy_mask)) { + /* periodic trigger IRQ - during pen sense */ + at91_adc_touch_data_handler(indio); + } else if (status & AT91_SAMA5D2_ISR_PENS) { + /* + * touching, but the measurements are not ready yet. + * read and ignore. + */ + status = at91_adc_readl(st, AT91_SAMA5D2_XPOSR); + status = at91_adc_readl(st, AT91_SAMA5D2_YPOSR); + status = at91_adc_readl(st, AT91_SAMA5D2_PRESSR); + } else if (iio_buffer_enabled(indio) && + (status & AT91_SAMA5D2_IER_DRDY)) { + /* triggered buffer without DMA */ + disable_irq_nosync(irq); + iio_trigger_poll(indio->trig); + } else if (iio_buffer_enabled(indio) && st->dma_st.dma_chan) { + /* triggered buffer with DMA - should not happen */ + disable_irq_nosync(irq); + WARN(true, "Unexpected irq occurred\n"); + } else if (!iio_buffer_enabled(indio)) { + /* software requested conversion */ + st->conversion_value = at91_adc_readl(st, st->chan->address); + st->conversion_done = true; + wake_up_interruptible(&st->wq_data_available); + } + return IRQ_HANDLED; +} + +static int at91_adc_read_info_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + u32 cor = 0; + u16 tmp_val; + int ret; + + /* + * Keep in mind that we cannot use software trigger or touchscreen + * if external trigger is enabled + */ + if (chan->type == IIO_POSITIONRELATIVE) { + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + mutex_lock(&st->lock); + + ret = at91_adc_read_position(st, chan->channel, + &tmp_val); + *val = tmp_val; + if (ret > 0) + ret = at91_adc_adjust_val_osr(st, val); + mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); + + return ret; + } + if (chan->type == IIO_PRESSURE) { + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + mutex_lock(&st->lock); + + ret = at91_adc_read_pressure(st, chan->channel, + &tmp_val); + *val = tmp_val; + if (ret > 0) + ret = at91_adc_adjust_val_osr(st, val); + mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); + + return ret; + } + + /* in this case we have a voltage channel */ + + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + mutex_lock(&st->lock); + + st->chan = chan; + + if (chan->differential) + cor = (BIT(chan->channel) | BIT(chan->channel2)) << + AT91_SAMA5D2_COR_DIFF_OFFSET; + + at91_adc_writel(st, AT91_SAMA5D2_COR, cor); + at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel)); + at91_adc_writel(st, AT91_SAMA5D2_IER, BIT(chan->channel)); + at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_START); + + ret = wait_event_interruptible_timeout(st->wq_data_available, + st->conversion_done, + msecs_to_jiffies(1000)); + if (ret == 0) + ret = -ETIMEDOUT; + + if (ret > 0) { + *val = st->conversion_value; + ret = at91_adc_adjust_val_osr(st, val); + if (chan->scan_type.sign == 's') + *val = sign_extend32(*val, + chan->scan_type.realbits - 1); + st->conversion_done = false; + } + + at91_adc_writel(st, AT91_SAMA5D2_IDR, BIT(chan->channel)); + at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel)); + + /* Needed to ACK the DRDY interruption */ + at91_adc_readl(st, AT91_SAMA5D2_LCDR); + + mutex_unlock(&st->lock); + + iio_device_release_direct_mode(indio_dev); + return ret; +} + +static int at91_adc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + return at91_adc_read_info_raw(indio_dev, chan, val); + case IIO_CHAN_INFO_SCALE: + *val = st->vref_uv / 1000; + if (chan->differential) + *val *= 2; + *val2 = chan->scan_type.realbits; + return IIO_VAL_FRACTIONAL_LOG2; + + case IIO_CHAN_INFO_SAMP_FREQ: + *val = at91_adc_get_sample_freq(st); + return IIO_VAL_INT; + + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + *val = st->oversampling_ratio; + return IIO_VAL_INT; + + default: + return -EINVAL; + } +} + +static int at91_adc_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + if ((val != AT91_OSR_1SAMPLES) && (val != AT91_OSR_4SAMPLES) && + (val != AT91_OSR_16SAMPLES)) + return -EINVAL; + /* if no change, optimize out */ + if (val == st->oversampling_ratio) + return 0; + mutex_lock(&st->lock); + st->oversampling_ratio = val; + /* update ratio */ + at91_adc_config_emr(st); + mutex_unlock(&st->lock); + return 0; + case IIO_CHAN_INFO_SAMP_FREQ: + if (val < st->soc_info.min_sample_rate || + val > st->soc_info.max_sample_rate) + return -EINVAL; + + mutex_lock(&st->lock); + at91_adc_setup_samp_freq(indio_dev, val); + mutex_unlock(&st->lock); + return 0; + default: + return -EINVAL; + }; +} + +static void at91_adc_dma_init(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct at91_adc_state *st = iio_priv(indio_dev); + struct dma_slave_config config = {0}; + /* + * We make the buffer double the size of the fifo, + * such that DMA uses one half of the buffer (full fifo size) + * and the software uses the other half to read/write. + */ + unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE * + AT91_BUFFER_MAX_CONVERSION_BYTES * 2, + PAGE_SIZE); + + if (st->dma_st.dma_chan) + return; + + st->dma_st.dma_chan = dma_request_chan(&pdev->dev, "rx"); + if (IS_ERR(st->dma_st.dma_chan)) { + dev_info(&pdev->dev, "can't get DMA channel\n"); + st->dma_st.dma_chan = NULL; + goto dma_exit; + } + + st->dma_st.rx_buf = dma_alloc_coherent(st->dma_st.dma_chan->device->dev, + pages * PAGE_SIZE, + &st->dma_st.rx_dma_buf, + GFP_KERNEL); + if (!st->dma_st.rx_buf) { + dev_info(&pdev->dev, "can't allocate coherent DMA area\n"); + goto dma_chan_disable; + } + + /* Configure DMA channel to read data register */ + config.direction = DMA_DEV_TO_MEM; + config.src_addr = (phys_addr_t)(st->dma_st.phys_addr + + AT91_SAMA5D2_LCDR); + config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; + config.src_maxburst = 1; + config.dst_maxburst = 1; + + if (dmaengine_slave_config(st->dma_st.dma_chan, &config)) { + dev_info(&pdev->dev, "can't configure DMA slave\n"); + goto dma_free_area; + } + + dev_info(&pdev->dev, "using %s for rx DMA transfers\n", + dma_chan_name(st->dma_st.dma_chan)); + + return; + +dma_free_area: + dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE, + st->dma_st.rx_buf, st->dma_st.rx_dma_buf); +dma_chan_disable: + dma_release_channel(st->dma_st.dma_chan); + st->dma_st.dma_chan = NULL; +dma_exit: + dev_info(&pdev->dev, "continuing without DMA support\n"); +} + +static void at91_adc_dma_disable(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct at91_adc_state *st = iio_priv(indio_dev); + unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE * + AT91_BUFFER_MAX_CONVERSION_BYTES * 2, + PAGE_SIZE); + + /* if we are not using DMA, just return */ + if (!st->dma_st.dma_chan) + return; + + /* wait for all transactions to be terminated first*/ + dmaengine_terminate_sync(st->dma_st.dma_chan); + + dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE, + st->dma_st.rx_buf, st->dma_st.rx_dma_buf); + dma_release_channel(st->dma_st.dma_chan); + st->dma_st.dma_chan = NULL; + + dev_info(&pdev->dev, "continuing without DMA support\n"); +} + +static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + int ret; + + if (val > AT91_HWFIFO_MAX_SIZE) + return -EINVAL; + + if (!st->selected_trig->hw_trig) { + dev_dbg(&indio_dev->dev, "we need hw trigger for DMA\n"); + return 0; + } + + dev_dbg(&indio_dev->dev, "new watermark is %u\n", val); + st->dma_st.watermark = val; + + /* + * The logic here is: if we have watermark 1, it means we do + * each conversion with it's own IRQ, thus we don't need DMA. + * If the watermark is higher, we do DMA to do all the transfers in bulk + */ + + if (val == 1) + at91_adc_dma_disable(to_platform_device(&indio_dev->dev)); + else if (val > 1) + at91_adc_dma_init(to_platform_device(&indio_dev->dev)); + + /* + * We can start the DMA only after setting the watermark and + * having the DMA initialization completed + */ + ret = at91_adc_buffer_prepare(indio_dev); + if (ret) + at91_adc_dma_disable(to_platform_device(&indio_dev->dev)); + + return ret; +} + +static int at91_adc_update_scan_mode(struct iio_dev *indio_dev, + const unsigned long *scan_mask) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + + if (bitmap_subset(scan_mask, &st->touch_st.channels_bitmask, + AT91_SAMA5D2_MAX_CHAN_IDX + 1)) + return 0; + /* + * if the new bitmap is a combination of touchscreen and regular + * channels, then we are not fine + */ + if (bitmap_intersects(&st->touch_st.channels_bitmask, scan_mask, + AT91_SAMA5D2_MAX_CHAN_IDX + 1)) + return -EINVAL; + return 0; +} + +static void at91_adc_hw_init(struct iio_dev *indio_dev) +{ + struct at91_adc_state *st = iio_priv(indio_dev); + + at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST); + at91_adc_writel(st, AT91_SAMA5D2_IDR, 0xffffffff); + /* + * Transfer field must be set to 2 according to the datasheet and + * allows different analog settings for each channel. + */ + at91_adc_writel(st, AT91_SAMA5D2_MR, + AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH); + + at91_adc_setup_samp_freq(indio_dev, st->soc_info.min_sample_rate); + + /* configure extended mode register */ + at91_adc_config_emr(st); +} + +static ssize_t at91_adc_get_fifo_state(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct at91_adc_state *st = iio_priv(indio_dev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", !!st->dma_st.dma_chan); +} + +static ssize_t at91_adc_get_watermark(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct at91_adc_state *st = iio_priv(indio_dev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", st->dma_st.watermark); +} + +static IIO_DEVICE_ATTR(hwfifo_enabled, 0444, + at91_adc_get_fifo_state, NULL, 0); +static IIO_DEVICE_ATTR(hwfifo_watermark, 0444, + at91_adc_get_watermark, NULL, 0); + +static IIO_CONST_ATTR(hwfifo_watermark_min, "2"); +static IIO_CONST_ATTR(hwfifo_watermark_max, AT91_HWFIFO_MAX_SIZE_STR); + +static IIO_CONST_ATTR(oversampling_ratio_available, + __stringify(AT91_OSR_1SAMPLES) " " + __stringify(AT91_OSR_4SAMPLES) " " + __stringify(AT91_OSR_16SAMPLES)); + +static struct attribute *at91_adc_attributes[] = { + &iio_const_attr_oversampling_ratio_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group at91_adc_attribute_group = { + .attrs = at91_adc_attributes, +}; + +static const struct attribute *at91_adc_fifo_attributes[] = { + &iio_const_attr_hwfifo_watermark_min.dev_attr.attr, + &iio_const_attr_hwfifo_watermark_max.dev_attr.attr, + &iio_dev_attr_hwfifo_watermark.dev_attr.attr, + &iio_dev_attr_hwfifo_enabled.dev_attr.attr, + NULL, +}; + +static const struct iio_info at91_adc_info = { + .attrs = &at91_adc_attribute_group, + .read_raw = &at91_adc_read_raw, + .write_raw = &at91_adc_write_raw, + .update_scan_mode = &at91_adc_update_scan_mode, + .of_xlate = &at91_adc_of_xlate, + .hwfifo_set_watermark = &at91_adc_set_watermark, +}; + +static int at91_adc_probe(struct platform_device *pdev) +{ + struct iio_dev *indio_dev; + struct at91_adc_state *st; + struct resource *res; + int ret, i; + u32 edge_type = IRQ_TYPE_NONE; + + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + indio_dev->name = dev_name(&pdev->dev); + indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE; + indio_dev->info = &at91_adc_info; + indio_dev->channels = at91_adc_channels; + indio_dev->num_channels = ARRAY_SIZE(at91_adc_channels); + + st = iio_priv(indio_dev); + st->indio_dev = indio_dev; + + bitmap_set(&st->touch_st.channels_bitmask, + AT91_SAMA5D2_TOUCH_X_CHAN_IDX, 1); + bitmap_set(&st->touch_st.channels_bitmask, + AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, 1); + bitmap_set(&st->touch_st.channels_bitmask, + AT91_SAMA5D2_TOUCH_P_CHAN_IDX, 1); + + st->oversampling_ratio = AT91_OSR_1SAMPLES; + + ret = of_property_read_u32(pdev->dev.of_node, + "atmel,min-sample-rate-hz", + &st->soc_info.min_sample_rate); + if (ret) { + dev_err(&pdev->dev, + "invalid or missing value for atmel,min-sample-rate-hz\n"); + return ret; + } + + ret = of_property_read_u32(pdev->dev.of_node, + "atmel,max-sample-rate-hz", + &st->soc_info.max_sample_rate); + if (ret) { + dev_err(&pdev->dev, + "invalid or missing value for atmel,max-sample-rate-hz\n"); + return ret; + } + + ret = of_property_read_u32(pdev->dev.of_node, "atmel,startup-time-ms", + &st->soc_info.startup_time); + if (ret) { + dev_err(&pdev->dev, + "invalid or missing value for atmel,startup-time-ms\n"); + return ret; + } + + ret = of_property_read_u32(pdev->dev.of_node, + "atmel,trigger-edge-type", &edge_type); + if (ret) { + dev_dbg(&pdev->dev, + "atmel,trigger-edge-type not specified, only software trigger available\n"); + } + + st->selected_trig = NULL; + + /* find the right trigger, or no trigger at all */ + for (i = 0; i < AT91_SAMA5D2_HW_TRIG_CNT + 1; i++) + if (at91_adc_trigger_list[i].edge_type == edge_type) { + st->selected_trig = &at91_adc_trigger_list[i]; + break; + } + + if (!st->selected_trig) { + dev_err(&pdev->dev, "invalid external trigger edge value\n"); + return -EINVAL; + } + + init_waitqueue_head(&st->wq_data_available); + mutex_init(&st->lock); + INIT_WORK(&st->touch_st.workq, at91_adc_workq_handler); + + st->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); + if (IS_ERR(st->base)) + return PTR_ERR(st->base); + + /* if we plan to use DMA, we need the physical address of the regs */ + st->dma_st.phys_addr = res->start; + + st->irq = platform_get_irq(pdev, 0); + if (st->irq <= 0) { + if (!st->irq) + st->irq = -ENXIO; + + return st->irq; + } + + st->per_clk = devm_clk_get(&pdev->dev, "adc_clk"); + if (IS_ERR(st->per_clk)) + return PTR_ERR(st->per_clk); + + st->reg = devm_regulator_get(&pdev->dev, "vddana"); + if (IS_ERR(st->reg)) + return PTR_ERR(st->reg); + + st->vref = devm_regulator_get(&pdev->dev, "vref"); + if (IS_ERR(st->vref)) + return PTR_ERR(st->vref); + + ret = devm_request_irq(&pdev->dev, st->irq, at91_adc_interrupt, 0, + pdev->dev.driver->name, indio_dev); + if (ret) + return ret; + + ret = regulator_enable(st->reg); + if (ret) + return ret; + + ret = regulator_enable(st->vref); + if (ret) + goto reg_disable; + + st->vref_uv = regulator_get_voltage(st->vref); + if (st->vref_uv <= 0) { + ret = -EINVAL; + goto vref_disable; + } + + at91_adc_hw_init(indio_dev); + + ret = clk_prepare_enable(st->per_clk); + if (ret) + goto vref_disable; + + platform_set_drvdata(pdev, indio_dev); + + ret = at91_adc_buffer_init(indio_dev); + if (ret < 0) { + dev_err(&pdev->dev, "couldn't initialize the buffer.\n"); + goto per_clk_disable_unprepare; + } + + if (st->selected_trig->hw_trig) { + ret = at91_adc_trigger_init(indio_dev); + if (ret < 0) { + dev_err(&pdev->dev, "couldn't setup the triggers.\n"); + goto per_clk_disable_unprepare; + } + /* + * Initially the iio buffer has a length of 2 and + * a watermark of 1 + */ + st->dma_st.watermark = 1; + + iio_buffer_set_attrs(indio_dev->buffer, + at91_adc_fifo_attributes); + } + + if (dma_coerce_mask_and_coherent(&indio_dev->dev, DMA_BIT_MASK(32))) + dev_info(&pdev->dev, "cannot set DMA mask to 32-bit\n"); + + ret = iio_device_register(indio_dev); + if (ret < 0) + goto dma_disable; + + if (st->selected_trig->hw_trig) + dev_info(&pdev->dev, "setting up trigger as %s\n", + st->selected_trig->name); + + dev_info(&pdev->dev, "version: %x\n", + readl_relaxed(st->base + AT91_SAMA5D2_VERSION)); + + return 0; + +dma_disable: + at91_adc_dma_disable(pdev); +per_clk_disable_unprepare: + clk_disable_unprepare(st->per_clk); +vref_disable: + regulator_disable(st->vref); +reg_disable: + regulator_disable(st->reg); + return ret; +} + +static int at91_adc_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct at91_adc_state *st = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + + at91_adc_dma_disable(pdev); + + clk_disable_unprepare(st->per_clk); + + regulator_disable(st->vref); + regulator_disable(st->reg); + + return 0; +} + +static __maybe_unused int at91_adc_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct at91_adc_state *st = iio_priv(indio_dev); + + if (iio_buffer_enabled(indio_dev)) + at91_adc_buffer_postdisable(indio_dev); + + /* + * Do a sofware reset of the ADC before we go to suspend. + * this will ensure that all pins are free from being muxed by the ADC + * and can be used by for other devices. + * Otherwise, ADC will hog them and we can't go to suspend mode. + */ + at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST); + + clk_disable_unprepare(st->per_clk); + regulator_disable(st->vref); + regulator_disable(st->reg); + + return pinctrl_pm_select_sleep_state(dev); +} + +static __maybe_unused int at91_adc_resume(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct at91_adc_state *st = iio_priv(indio_dev); + int ret; + + ret = pinctrl_pm_select_default_state(dev); + if (ret) + goto resume_failed; + + ret = regulator_enable(st->reg); + if (ret) + goto resume_failed; + + ret = regulator_enable(st->vref); + if (ret) + goto reg_disable_resume; + + ret = clk_prepare_enable(st->per_clk); + if (ret) + goto vref_disable_resume; + + at91_adc_hw_init(indio_dev); + + /* reconfiguring trigger hardware state */ + if (!iio_buffer_enabled(indio_dev)) + return 0; + + ret = at91_adc_buffer_prepare(indio_dev); + if (ret) + goto vref_disable_resume; + + return at91_adc_configure_trigger(st->trig, true); + +vref_disable_resume: + regulator_disable(st->vref); +reg_disable_resume: + regulator_disable(st->reg); +resume_failed: + dev_err(&indio_dev->dev, "failed to resume\n"); + return ret; +} + +static SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend, at91_adc_resume); + +static const struct of_device_id at91_adc_dt_match[] = { + { + .compatible = "atmel,sama5d2-adc", + }, { + /* sentinel */ + } +}; +MODULE_DEVICE_TABLE(of, at91_adc_dt_match); + +static struct platform_driver at91_adc_driver = { + .probe = at91_adc_probe, + .remove = at91_adc_remove, + .driver = { + .name = "at91-sama5d2_adc", + .of_match_table = at91_adc_dt_match, + .pm = &at91_adc_pm_ops, + }, +}; +module_platform_driver(at91_adc_driver) + +MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@atmel.com>"); +MODULE_DESCRIPTION("Atmel AT91 SAMA5D2 ADC"); +MODULE_LICENSE("GPL v2"); |