diff options
Diffstat (limited to 'drivers/iio/adc/at91-sama5d2_adc.c')
| -rw-r--r-- | drivers/iio/adc/at91-sama5d2_adc.c | 780 |
1 files changed, 705 insertions, 75 deletions
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index 8729d6524b4d..e02f7d1c86bc 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -102,14 +102,26 @@ #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 - 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 */ @@ -118,6 +130,15 @@ #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 */ @@ -131,8 +152,38 @@ #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 */ @@ -151,6 +202,12 @@ #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 @@ -169,6 +226,22 @@ #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. @@ -184,6 +257,11 @@ #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, \ @@ -192,12 +270,13 @@ .scan_index = num, \ .scan_type = { \ .sign = 'u', \ - .realbits = 12, \ + .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),\ + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\ + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ .datasheet_name = "CH"#num, \ .indexed = 1, \ } @@ -212,16 +291,50 @@ .scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT, \ .scan_type = { \ .sign = 's', \ - .realbits = 12, \ + .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),\ + .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) @@ -260,6 +373,22 @@ struct at91_adc_dma { s64 dma_ts; }; +/** + * 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; @@ -267,14 +396,17 @@ struct at91_adc_state { 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; u16 buffer[AT91_BUFFER_MAX_HWORDS]; /* * lock to prevent concurrent 'single conversion' requests through @@ -329,8 +461,10 @@ static const struct iio_chan_spec at91_adc_channels[] = { 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_SINGLE_CHAN_CNT - + AT91_SAMA5D2_DIFF_CHAN_CNT + 1), + 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) @@ -354,6 +488,231 @@ at91_adc_chan_get(struct iio_dev *indio_dev, int chan) 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 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(&iio_priv_to_dev(st)->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(&iio_priv_to_dev(st)->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); @@ -375,6 +734,11 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state) if (!chan) continue; + /* these channel types cannot be handled by this trigger */ + if (chan->type == IIO_POSITIONRELATIVE || + chan->type == IIO_PRESSURE) + continue; + if (state) { at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel)); @@ -520,7 +884,20 @@ static int at91_adc_dma_start(struct iio_dev *indio_dev) static int at91_adc_buffer_postenable(struct iio_dev *indio_dev) { int ret; + struct at91_adc_state *st = iio_priv(indio_dev); + /* check if we are enabling triggered buffer or the touchscreen */ + if (bitmap_subset(indio_dev->active_scan_mask, + &st->touch_st.channels_bitmask, + AT91_SAMA5D2_MAX_CHAN_IDX + 1)) { + /* touchscreen enabling */ + 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 postenable failed\n"); @@ -536,6 +913,18 @@ static int at91_adc_buffer_predisable(struct iio_dev *indio_dev) int ret; u8 bit; + /* check if we are disabling triggered buffer or the touchscreen */ + if (bitmap_subset(indio_dev->active_scan_mask, + &st->touch_st.channels_bitmask, + AT91_SAMA5D2_MAX_CHAN_IDX + 1)) { + /* touchscreen disable */ + 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; + + /* continue with the triggered buffer */ ret = iio_triggered_buffer_predisable(indio_dev); if (ret < 0) dev_err(&indio_dev->dev, "buffer predisable failed\n"); @@ -558,6 +947,10 @@ static int at91_adc_buffer_predisable(struct iio_dev *indio_dev) if (!chan) continue; + /* these channel types are virtual, no need to do anything */ + if (chan->type == IIO_POSITIONRELATIVE || + chan->type == IIO_PRESSURE) + continue; if (st->dma_st.dma_chan) at91_adc_readl(st, chan->address); } @@ -613,6 +1006,7 @@ static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev, { struct at91_adc_state *st = iio_priv(indio_dev); int i = 0; + int val; u8 bit; for_each_set_bit(bit, indio_dev->active_scan_mask, @@ -622,7 +1016,24 @@ static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev, if (!chan) continue; - st->buffer[i] = at91_adc_readl(st, chan->address); + /* + * 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, @@ -654,6 +1065,14 @@ static void at91_adc_trigger_handler_dma(struct iio_dev *indio_dev) 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)); @@ -688,9 +1107,20 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p) static int at91_adc_buffer_init(struct iio_dev *indio) { - return devm_iio_triggered_buffer_setup(&indio->dev, indio, + struct at91_adc_state *st = iio_priv(indio); + + if (st->selected_trig->hw_trig) { + return devm_iio_triggered_buffer_setup(&indio->dev, indio, &iio_pollfunc_store_time, &at91_adc_trigger_handler, &at91_buffer_setup_ops); + } + /* + * we need to prepare the buffer ops in case we will get + * another buffer attached (like a callback buffer for the touchscreen) + */ + indio->setup_ops = &at91_buffer_setup_ops; + + return 0; } static unsigned at91_adc_startup_time(unsigned startup_time_min, @@ -736,19 +1166,83 @@ static void at91_adc_setup_samp_freq(struct at91_adc_state *st, unsigned freq) dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u\n", freq, startup, prescal); + st->current_sample_rate = freq; } -static unsigned at91_adc_get_sample_freq(struct at91_adc_state *st) +static inline unsigned at91_adc_get_sample_freq(struct at91_adc_state *st) { - unsigned f_adc, f_per = clk_get_rate(st->per_clk); - unsigned mr, prescal; + return st->current_sample_rate; +} - mr = at91_adc_readl(st, AT91_SAMA5D2_MR); - prescal = (mr >> AT91_SAMA5D2_MR_PRESCAL_OFFSET) - & AT91_SAMA5D2_MR_PRESCAL_MAX; - f_adc = f_per / (2 * (prescal + 1)); +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 at91_adc_state *st) +{ + struct iio_dev *indio_dev = iio_priv_to_dev(st); + + 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 = iio_priv_to_dev(st); - return f_adc; + iio_push_to_buffers(indio_dev, st->buffer); } static irqreturn_t at91_adc_interrupt(int irq, void *private) @@ -757,17 +1251,39 @@ static irqreturn_t at91_adc_interrupt(int irq, void *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 (iio_buffer_enabled(indio) && !st->dma_st.dma_chan) { + 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(st); + } 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) && !st->dma_st.dma_chan) { + /* 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); @@ -775,58 +1291,97 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private) return IRQ_HANDLED; } -static int at91_adc_read_raw(struct iio_dev *indio_dev, - struct iio_chan_spec const *chan, - int *val, int *val2, long mask) +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; int ret; - switch (mask) { - case IIO_CHAN_INFO_RAW: - /* we cannot use software trigger if hw trigger enabled */ + /* + * 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); - st->chan = chan; + ret = at91_adc_read_position(st, chan->channel, + (u16 *)val); + mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); - 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; - if (chan->scan_type.sign == 's') - *val = sign_extend32(*val, 11); - ret = IIO_VAL_INT; - st->conversion_done = false; - } + return at91_adc_adjust_val_osr(st, val); + } + if (chan->type == IIO_PRESSURE) { + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + mutex_lock(&st->lock); - at91_adc_writel(st, AT91_SAMA5D2_IDR, BIT(chan->channel)); - at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel)); + ret = at91_adc_read_pressure(st, chan->channel, + (u16 *)val); + mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); - /* Needed to ACK the DRDY interruption */ - at91_adc_readl(st, AT91_SAMA5D2_LCDR); + return at91_adc_adjust_val_osr(st, val); + } - mutex_unlock(&st->lock); + /* in this case we have a voltage channel */ - iio_device_release_direct_mode(indio_dev); + 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, 11); + 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) @@ -838,6 +1393,10 @@ static int at91_adc_read_raw(struct iio_dev *indio_dev, *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; } @@ -849,16 +1408,28 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev, { struct at91_adc_state *st = iio_priv(indio_dev); - if (mask != IIO_CHAN_INFO_SAMP_FREQ) - return -EINVAL; + 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; + st->oversampling_ratio = val; + /* update ratio */ + at91_adc_config_emr(st); + 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; - if (val < st->soc_info.min_sample_rate || - val > st->soc_info.max_sample_rate) + at91_adc_setup_samp_freq(st, val); + return 0; + default: return -EINVAL; - - at91_adc_setup_samp_freq(st, val); - - return 0; + }; } static void at91_adc_dma_init(struct platform_device *pdev) @@ -974,11 +1545,23 @@ static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val) return 0; } -static const struct iio_info at91_adc_info = { - .read_raw = &at91_adc_read_raw, - .write_raw = &at91_adc_write_raw, - .hwfifo_set_watermark = &at91_adc_set_watermark, -}; +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 at91_adc_state *st) { @@ -992,6 +1575,9 @@ static void at91_adc_hw_init(struct at91_adc_state *st) AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH); at91_adc_setup_samp_freq(st, 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, @@ -1022,6 +1608,20 @@ static IIO_DEVICE_ATTR(hwfifo_watermark, 0444, 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, @@ -1030,6 +1630,15 @@ static const struct attribute *at91_adc_fifo_attributes[] = { 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; @@ -1044,13 +1653,22 @@ static int at91_adc_probe(struct platform_device *pdev) indio_dev->dev.parent = &pdev->dev; indio_dev->name = dev_name(&pdev->dev); - indio_dev->modes = INDIO_DIRECT_MODE; + 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); + 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); @@ -1100,6 +1718,7 @@ static int at91_adc_probe(struct platform_device *pdev) init_waitqueue_head(&st->wq_data_available); mutex_init(&st->lock); + INIT_WORK(&st->touch_st.workq, at91_adc_workq_handler); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) @@ -1159,13 +1778,13 @@ static int at91_adc_probe(struct platform_device *pdev) platform_set_drvdata(pdev, indio_dev); - if (st->selected_trig->hw_trig) { - 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; - } + 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"); @@ -1272,9 +1891,20 @@ static __maybe_unused int at91_adc_resume(struct device *dev) at91_adc_hw_init(st); /* reconfiguring trigger hardware state */ - if (iio_buffer_enabled(indio_dev)) - at91_adc_configure_trigger(st->trig, true); + if (!iio_buffer_enabled(indio_dev)) + return 0; + + /* check if we are enabling triggered buffer or the touchscreen */ + if (bitmap_subset(indio_dev->active_scan_mask, + &st->touch_st.channels_bitmask, + AT91_SAMA5D2_MAX_CHAN_IDX + 1)) { + /* touchscreen enabling */ + return at91_adc_configure_touch(st, true); + } else { + return at91_adc_configure_trigger(st->trig, true); + } + /* not needed but more explicit */ return 0; vref_disable_resume: |