19374e8f5SOleksij Rempel // SPDX-License-Identifier: GPL-2.0
29374e8f5SOleksij Rempel /*
39374e8f5SOleksij Rempel * Texas Instruments TSC2046 SPI ADC driver
49374e8f5SOleksij Rempel *
59374e8f5SOleksij Rempel * Copyright (c) 2021 Oleksij Rempel <kernel@pengutronix.de>, Pengutronix
69374e8f5SOleksij Rempel */
79374e8f5SOleksij Rempel
89374e8f5SOleksij Rempel #include <linux/bitfield.h>
99374e8f5SOleksij Rempel #include <linux/delay.h>
109374e8f5SOleksij Rempel #include <linux/module.h>
11a616a6a1SOleksij Rempel #include <linux/regulator/consumer.h>
129374e8f5SOleksij Rempel #include <linux/spi/spi.h>
13a616a6a1SOleksij Rempel #include <linux/units.h>
149374e8f5SOleksij Rempel
159374e8f5SOleksij Rempel #include <asm/unaligned.h>
169374e8f5SOleksij Rempel
179374e8f5SOleksij Rempel #include <linux/iio/buffer.h>
189374e8f5SOleksij Rempel #include <linux/iio/trigger_consumer.h>
199374e8f5SOleksij Rempel #include <linux/iio/triggered_buffer.h>
209374e8f5SOleksij Rempel #include <linux/iio/trigger.h>
219374e8f5SOleksij Rempel
229374e8f5SOleksij Rempel /*
239374e8f5SOleksij Rempel * The PENIRQ of TSC2046 controller is implemented as level shifter attached to
249374e8f5SOleksij Rempel * the X+ line. If voltage of the X+ line reaches a specific level the IRQ will
259374e8f5SOleksij Rempel * be activated or deactivated.
269374e8f5SOleksij Rempel * To make this kind of IRQ reusable as trigger following additions were
279374e8f5SOleksij Rempel * implemented:
289374e8f5SOleksij Rempel * - rate limiting:
299374e8f5SOleksij Rempel * For typical touchscreen use case, we need to trigger about each 10ms.
309374e8f5SOleksij Rempel * - hrtimer:
319374e8f5SOleksij Rempel * Continue triggering at least once after the IRQ was deactivated. Then
329374e8f5SOleksij Rempel * deactivate this trigger to stop sampling in order to reduce power
339374e8f5SOleksij Rempel * consumption.
349374e8f5SOleksij Rempel */
359374e8f5SOleksij Rempel
369374e8f5SOleksij Rempel #define TI_TSC2046_NAME "tsc2046"
379374e8f5SOleksij Rempel
389374e8f5SOleksij Rempel /* This driver doesn't aim at the peak continuous sample rate */
399374e8f5SOleksij Rempel #define TI_TSC2046_MAX_SAMPLE_RATE 125000
409374e8f5SOleksij Rempel #define TI_TSC2046_SAMPLE_BITS \
419374e8f5SOleksij Rempel BITS_PER_TYPE(struct tsc2046_adc_atom)
429374e8f5SOleksij Rempel #define TI_TSC2046_MAX_CLK_FREQ \
439374e8f5SOleksij Rempel (TI_TSC2046_MAX_SAMPLE_RATE * TI_TSC2046_SAMPLE_BITS)
449374e8f5SOleksij Rempel
459374e8f5SOleksij Rempel #define TI_TSC2046_SAMPLE_INTERVAL_US 10000
469374e8f5SOleksij Rempel
479374e8f5SOleksij Rempel #define TI_TSC2046_START BIT(7)
489374e8f5SOleksij Rempel #define TI_TSC2046_ADDR GENMASK(6, 4)
499374e8f5SOleksij Rempel #define TI_TSC2046_ADDR_TEMP1 7
509374e8f5SOleksij Rempel #define TI_TSC2046_ADDR_AUX 6
519374e8f5SOleksij Rempel #define TI_TSC2046_ADDR_X 5
529374e8f5SOleksij Rempel #define TI_TSC2046_ADDR_Z2 4
539374e8f5SOleksij Rempel #define TI_TSC2046_ADDR_Z1 3
549374e8f5SOleksij Rempel #define TI_TSC2046_ADDR_VBAT 2
559374e8f5SOleksij Rempel #define TI_TSC2046_ADDR_Y 1
569374e8f5SOleksij Rempel #define TI_TSC2046_ADDR_TEMP0 0
579374e8f5SOleksij Rempel
589374e8f5SOleksij Rempel /*
599374e8f5SOleksij Rempel * The mode bit sets the resolution of the ADC. With this bit low, the next
609374e8f5SOleksij Rempel * conversion has 12-bit resolution, whereas with this bit high, the next
619374e8f5SOleksij Rempel * conversion has 8-bit resolution. This driver is optimized for 12-bit mode.
629374e8f5SOleksij Rempel * So, for this driver, this bit should stay zero.
639374e8f5SOleksij Rempel */
649374e8f5SOleksij Rempel #define TI_TSC2046_8BIT_MODE BIT(3)
659374e8f5SOleksij Rempel
669374e8f5SOleksij Rempel /*
679374e8f5SOleksij Rempel * SER/DFR - The SER/DFR bit controls the reference mode, either single-ended
689374e8f5SOleksij Rempel * (high) or differential (low).
699374e8f5SOleksij Rempel */
709374e8f5SOleksij Rempel #define TI_TSC2046_SER BIT(2)
719374e8f5SOleksij Rempel
729374e8f5SOleksij Rempel /*
739374e8f5SOleksij Rempel * If VREF_ON and ADC_ON are both zero, then the chip operates in
749374e8f5SOleksij Rempel * auto-wake/suspend mode. In most case this bits should stay zero.
759374e8f5SOleksij Rempel */
769374e8f5SOleksij Rempel #define TI_TSC2046_PD1_VREF_ON BIT(1)
779374e8f5SOleksij Rempel #define TI_TSC2046_PD0_ADC_ON BIT(0)
789374e8f5SOleksij Rempel
799374e8f5SOleksij Rempel /*
809374e8f5SOleksij Rempel * All supported devices can do 8 or 12bit resolution. This driver
819374e8f5SOleksij Rempel * supports only 12bit mode, here we have a 16bit data transfer, where
829374e8f5SOleksij Rempel * the MSB and the 3 LSB are 0.
839374e8f5SOleksij Rempel */
849374e8f5SOleksij Rempel #define TI_TSC2046_DATA_12BIT GENMASK(14, 3)
859374e8f5SOleksij Rempel
869374e8f5SOleksij Rempel #define TI_TSC2046_MAX_CHAN 8
8784e5d889SOleksij Rempel #define TI_TSC2046_MIN_POLL_CNT 3
8884e5d889SOleksij Rempel #define TI_TSC2046_EXT_POLL_CNT 3
8984e5d889SOleksij Rempel #define TI_TSC2046_POLL_CNT \
9084e5d889SOleksij Rempel (TI_TSC2046_MIN_POLL_CNT + TI_TSC2046_EXT_POLL_CNT)
91b617693aSOleksij Rempel #define TI_TSC2046_INT_VREF 2500
929374e8f5SOleksij Rempel
939374e8f5SOleksij Rempel /* Represents a HW sample */
949374e8f5SOleksij Rempel struct tsc2046_adc_atom {
959374e8f5SOleksij Rempel /*
969374e8f5SOleksij Rempel * Command transmitted to the controller. This field is empty on the RX
979374e8f5SOleksij Rempel * buffer.
989374e8f5SOleksij Rempel */
999374e8f5SOleksij Rempel u8 cmd;
1009374e8f5SOleksij Rempel /*
1019374e8f5SOleksij Rempel * Data received from the controller. This field is empty for the TX
1029374e8f5SOleksij Rempel * buffer
1039374e8f5SOleksij Rempel */
1049374e8f5SOleksij Rempel __be16 data;
1059374e8f5SOleksij Rempel } __packed;
1069374e8f5SOleksij Rempel
1079374e8f5SOleksij Rempel /* Layout of atomic buffers within big buffer */
1089374e8f5SOleksij Rempel struct tsc2046_adc_group_layout {
1099374e8f5SOleksij Rempel /* Group offset within the SPI RX buffer */
1109374e8f5SOleksij Rempel unsigned int offset;
1119374e8f5SOleksij Rempel /*
1129374e8f5SOleksij Rempel * Amount of tsc2046_adc_atom structs within the same command gathered
1139374e8f5SOleksij Rempel * within same group.
1149374e8f5SOleksij Rempel */
1159374e8f5SOleksij Rempel unsigned int count;
1169374e8f5SOleksij Rempel /*
1179374e8f5SOleksij Rempel * Settling samples (tsc2046_adc_atom structs) which should be skipped
1189374e8f5SOleksij Rempel * before good samples will start.
1199374e8f5SOleksij Rempel */
1209374e8f5SOleksij Rempel unsigned int skip;
1219374e8f5SOleksij Rempel };
1229374e8f5SOleksij Rempel
1239374e8f5SOleksij Rempel struct tsc2046_adc_dcfg {
1249374e8f5SOleksij Rempel const struct iio_chan_spec *channels;
1259374e8f5SOleksij Rempel unsigned int num_channels;
1269374e8f5SOleksij Rempel };
1279374e8f5SOleksij Rempel
1289374e8f5SOleksij Rempel struct tsc2046_adc_ch_cfg {
1299374e8f5SOleksij Rempel unsigned int settling_time_us;
1309374e8f5SOleksij Rempel unsigned int oversampling_ratio;
1319374e8f5SOleksij Rempel };
1329374e8f5SOleksij Rempel
13384e5d889SOleksij Rempel enum tsc2046_state {
13484e5d889SOleksij Rempel TSC2046_STATE_SHUTDOWN,
13584e5d889SOleksij Rempel TSC2046_STATE_STANDBY,
13684e5d889SOleksij Rempel TSC2046_STATE_POLL,
13784e5d889SOleksij Rempel TSC2046_STATE_POLL_IRQ_DISABLE,
13884e5d889SOleksij Rempel TSC2046_STATE_ENABLE_IRQ,
13984e5d889SOleksij Rempel };
14084e5d889SOleksij Rempel
1419374e8f5SOleksij Rempel struct tsc2046_adc_priv {
1429374e8f5SOleksij Rempel struct spi_device *spi;
1439374e8f5SOleksij Rempel const struct tsc2046_adc_dcfg *dcfg;
144a616a6a1SOleksij Rempel struct regulator *vref_reg;
1459374e8f5SOleksij Rempel
1469374e8f5SOleksij Rempel struct iio_trigger *trig;
1479374e8f5SOleksij Rempel struct hrtimer trig_timer;
14884e5d889SOleksij Rempel enum tsc2046_state state;
14984e5d889SOleksij Rempel int poll_cnt;
15084e5d889SOleksij Rempel spinlock_t state_lock;
1519374e8f5SOleksij Rempel
1529374e8f5SOleksij Rempel struct spi_transfer xfer;
1539374e8f5SOleksij Rempel struct spi_message msg;
1549374e8f5SOleksij Rempel
1559374e8f5SOleksij Rempel struct {
1569374e8f5SOleksij Rempel /* Scan data for each channel */
1579374e8f5SOleksij Rempel u16 data[TI_TSC2046_MAX_CHAN];
1589374e8f5SOleksij Rempel /* Timestamp */
1599374e8f5SOleksij Rempel s64 ts __aligned(8);
1609374e8f5SOleksij Rempel } scan_buf;
1619374e8f5SOleksij Rempel
1629374e8f5SOleksij Rempel /*
1639374e8f5SOleksij Rempel * Lock to protect the layout and the SPI transfer buffer.
1649374e8f5SOleksij Rempel * tsc2046_adc_group_layout can be changed within update_scan_mode(),
1659374e8f5SOleksij Rempel * in this case the l[] and tx/rx buffer will be out of sync to each
1669374e8f5SOleksij Rempel * other.
1679374e8f5SOleksij Rempel */
1689374e8f5SOleksij Rempel struct mutex slock;
1699374e8f5SOleksij Rempel struct tsc2046_adc_group_layout l[TI_TSC2046_MAX_CHAN];
1709374e8f5SOleksij Rempel struct tsc2046_adc_atom *rx;
1719374e8f5SOleksij Rempel struct tsc2046_adc_atom *tx;
1729374e8f5SOleksij Rempel
1739374e8f5SOleksij Rempel unsigned int count;
1749374e8f5SOleksij Rempel unsigned int groups;
1759374e8f5SOleksij Rempel u32 effective_speed_hz;
1769374e8f5SOleksij Rempel u32 scan_interval_us;
1779374e8f5SOleksij Rempel u32 time_per_scan_us;
1789374e8f5SOleksij Rempel u32 time_per_bit_ns;
179a616a6a1SOleksij Rempel unsigned int vref_mv;
1809374e8f5SOleksij Rempel
1819374e8f5SOleksij Rempel struct tsc2046_adc_ch_cfg ch_cfg[TI_TSC2046_MAX_CHAN];
1829374e8f5SOleksij Rempel };
1839374e8f5SOleksij Rempel
1849374e8f5SOleksij Rempel #define TI_TSC2046_V_CHAN(index, bits, name) \
1859374e8f5SOleksij Rempel { \
1869374e8f5SOleksij Rempel .type = IIO_VOLTAGE, \
1879374e8f5SOleksij Rempel .indexed = 1, \
1889374e8f5SOleksij Rempel .channel = index, \
189b617693aSOleksij Rempel .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
190b617693aSOleksij Rempel .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
1919374e8f5SOleksij Rempel .datasheet_name = "#name", \
1929374e8f5SOleksij Rempel .scan_index = index, \
1939374e8f5SOleksij Rempel .scan_type = { \
1949374e8f5SOleksij Rempel .sign = 'u', \
1959374e8f5SOleksij Rempel .realbits = bits, \
1969374e8f5SOleksij Rempel .storagebits = 16, \
1979374e8f5SOleksij Rempel .endianness = IIO_CPU, \
1989374e8f5SOleksij Rempel }, \
1999374e8f5SOleksij Rempel }
2009374e8f5SOleksij Rempel
2019374e8f5SOleksij Rempel #define DECLARE_TI_TSC2046_8_CHANNELS(name, bits) \
2029374e8f5SOleksij Rempel const struct iio_chan_spec name ## _channels[] = { \
2039374e8f5SOleksij Rempel TI_TSC2046_V_CHAN(0, bits, TEMP0), \
2049374e8f5SOleksij Rempel TI_TSC2046_V_CHAN(1, bits, Y), \
2059374e8f5SOleksij Rempel TI_TSC2046_V_CHAN(2, bits, VBAT), \
2069374e8f5SOleksij Rempel TI_TSC2046_V_CHAN(3, bits, Z1), \
2079374e8f5SOleksij Rempel TI_TSC2046_V_CHAN(4, bits, Z2), \
2089374e8f5SOleksij Rempel TI_TSC2046_V_CHAN(5, bits, X), \
2099374e8f5SOleksij Rempel TI_TSC2046_V_CHAN(6, bits, AUX), \
2109374e8f5SOleksij Rempel TI_TSC2046_V_CHAN(7, bits, TEMP1), \
2119374e8f5SOleksij Rempel IIO_CHAN_SOFT_TIMESTAMP(8), \
2129374e8f5SOleksij Rempel }
2139374e8f5SOleksij Rempel
2149374e8f5SOleksij Rempel static DECLARE_TI_TSC2046_8_CHANNELS(tsc2046_adc, 12);
2159374e8f5SOleksij Rempel
2169374e8f5SOleksij Rempel static const struct tsc2046_adc_dcfg tsc2046_adc_dcfg_tsc2046e = {
2179374e8f5SOleksij Rempel .channels = tsc2046_adc_channels,
2189374e8f5SOleksij Rempel .num_channels = ARRAY_SIZE(tsc2046_adc_channels),
2199374e8f5SOleksij Rempel };
2209374e8f5SOleksij Rempel
2219374e8f5SOleksij Rempel /*
2229374e8f5SOleksij Rempel * Convert time to a number of samples which can be transferred within this
2239374e8f5SOleksij Rempel * time.
2249374e8f5SOleksij Rempel */
tsc2046_adc_time_to_count(struct tsc2046_adc_priv * priv,unsigned long time)2259374e8f5SOleksij Rempel static unsigned int tsc2046_adc_time_to_count(struct tsc2046_adc_priv *priv,
2269374e8f5SOleksij Rempel unsigned long time)
2279374e8f5SOleksij Rempel {
2289374e8f5SOleksij Rempel unsigned int bit_count, sample_count;
2299374e8f5SOleksij Rempel
2309374e8f5SOleksij Rempel bit_count = DIV_ROUND_UP(time * NSEC_PER_USEC, priv->time_per_bit_ns);
2319374e8f5SOleksij Rempel sample_count = DIV_ROUND_UP(bit_count, TI_TSC2046_SAMPLE_BITS);
2329374e8f5SOleksij Rempel
2339374e8f5SOleksij Rempel dev_dbg(&priv->spi->dev, "Effective speed %u, time per bit: %u, count bits: %u, count samples: %u\n",
2349374e8f5SOleksij Rempel priv->effective_speed_hz, priv->time_per_bit_ns,
2359374e8f5SOleksij Rempel bit_count, sample_count);
2369374e8f5SOleksij Rempel
2379374e8f5SOleksij Rempel return sample_count;
2389374e8f5SOleksij Rempel }
2399374e8f5SOleksij Rempel
tsc2046_adc_get_cmd(struct tsc2046_adc_priv * priv,int ch_idx,bool keep_power)2409374e8f5SOleksij Rempel static u8 tsc2046_adc_get_cmd(struct tsc2046_adc_priv *priv, int ch_idx,
2419374e8f5SOleksij Rempel bool keep_power)
2429374e8f5SOleksij Rempel {
2439374e8f5SOleksij Rempel u32 pd;
2449374e8f5SOleksij Rempel
2459374e8f5SOleksij Rempel /*
2469374e8f5SOleksij Rempel * if PD bits are 0, controller will automatically disable ADC, VREF and
2479374e8f5SOleksij Rempel * enable IRQ.
2489374e8f5SOleksij Rempel */
2499374e8f5SOleksij Rempel if (keep_power)
2509374e8f5SOleksij Rempel pd = TI_TSC2046_PD0_ADC_ON;
2519374e8f5SOleksij Rempel else
2529374e8f5SOleksij Rempel pd = 0;
2539374e8f5SOleksij Rempel
254b617693aSOleksij Rempel switch (ch_idx) {
255b617693aSOleksij Rempel case TI_TSC2046_ADDR_TEMP1:
256b617693aSOleksij Rempel case TI_TSC2046_ADDR_AUX:
257b617693aSOleksij Rempel case TI_TSC2046_ADDR_VBAT:
258b617693aSOleksij Rempel case TI_TSC2046_ADDR_TEMP0:
259a616a6a1SOleksij Rempel pd |= TI_TSC2046_SER;
260a616a6a1SOleksij Rempel if (!priv->vref_reg)
261a616a6a1SOleksij Rempel pd |= TI_TSC2046_PD1_VREF_ON;
262b617693aSOleksij Rempel }
263b617693aSOleksij Rempel
2649374e8f5SOleksij Rempel return TI_TSC2046_START | FIELD_PREP(TI_TSC2046_ADDR, ch_idx) | pd;
2659374e8f5SOleksij Rempel }
2669374e8f5SOleksij Rempel
tsc2046_adc_get_value(struct tsc2046_adc_atom * buf)2679374e8f5SOleksij Rempel static u16 tsc2046_adc_get_value(struct tsc2046_adc_atom *buf)
2689374e8f5SOleksij Rempel {
2699374e8f5SOleksij Rempel return FIELD_GET(TI_TSC2046_DATA_12BIT, get_unaligned_be16(&buf->data));
2709374e8f5SOleksij Rempel }
2719374e8f5SOleksij Rempel
tsc2046_adc_read_one(struct tsc2046_adc_priv * priv,int ch_idx,u32 * effective_speed_hz)2729374e8f5SOleksij Rempel static int tsc2046_adc_read_one(struct tsc2046_adc_priv *priv, int ch_idx,
2739374e8f5SOleksij Rempel u32 *effective_speed_hz)
2749374e8f5SOleksij Rempel {
275b617693aSOleksij Rempel struct tsc2046_adc_ch_cfg *ch = &priv->ch_cfg[ch_idx];
276b617693aSOleksij Rempel struct tsc2046_adc_atom *rx_buf, *tx_buf;
277b617693aSOleksij Rempel unsigned int val, val_normalized = 0;
278b617693aSOleksij Rempel int ret, i, count_skip = 0, max_count;
2799374e8f5SOleksij Rempel struct spi_transfer xfer;
2809374e8f5SOleksij Rempel struct spi_message msg;
281b617693aSOleksij Rempel u8 cmd;
282b617693aSOleksij Rempel
283b617693aSOleksij Rempel if (!effective_speed_hz) {
284b617693aSOleksij Rempel count_skip = tsc2046_adc_time_to_count(priv, ch->settling_time_us);
285b617693aSOleksij Rempel max_count = count_skip + ch->oversampling_ratio;
286b617693aSOleksij Rempel } else {
287b617693aSOleksij Rempel max_count = 1;
288b617693aSOleksij Rempel }
289b617693aSOleksij Rempel
290b617693aSOleksij Rempel if (sizeof(*tx_buf) * max_count > PAGE_SIZE)
291b617693aSOleksij Rempel return -ENOSPC;
292b617693aSOleksij Rempel
293b617693aSOleksij Rempel tx_buf = kcalloc(max_count, sizeof(*tx_buf), GFP_KERNEL);
294b617693aSOleksij Rempel if (!tx_buf)
295b617693aSOleksij Rempel return -ENOMEM;
296b617693aSOleksij Rempel
297b617693aSOleksij Rempel rx_buf = kcalloc(max_count, sizeof(*rx_buf), GFP_KERNEL);
298b617693aSOleksij Rempel if (!rx_buf) {
299b617693aSOleksij Rempel ret = -ENOMEM;
300b617693aSOleksij Rempel goto free_tx;
301b617693aSOleksij Rempel }
302b617693aSOleksij Rempel
303b617693aSOleksij Rempel /*
304b617693aSOleksij Rempel * Do not enable automatic power down on working samples. Otherwise the
305b617693aSOleksij Rempel * plates will never be completely charged.
306b617693aSOleksij Rempel */
307b617693aSOleksij Rempel cmd = tsc2046_adc_get_cmd(priv, ch_idx, true);
308b617693aSOleksij Rempel
309b617693aSOleksij Rempel for (i = 0; i < max_count - 1; i++)
310b617693aSOleksij Rempel tx_buf[i].cmd = cmd;
311b617693aSOleksij Rempel
312b617693aSOleksij Rempel /* automatically power down on last sample */
313b617693aSOleksij Rempel tx_buf[i].cmd = tsc2046_adc_get_cmd(priv, ch_idx, false);
3149374e8f5SOleksij Rempel
3159374e8f5SOleksij Rempel memset(&xfer, 0, sizeof(xfer));
316b617693aSOleksij Rempel xfer.tx_buf = tx_buf;
317b617693aSOleksij Rempel xfer.rx_buf = rx_buf;
318b617693aSOleksij Rempel xfer.len = sizeof(*tx_buf) * max_count;
3199374e8f5SOleksij Rempel spi_message_init_with_transfers(&msg, &xfer, 1);
3209374e8f5SOleksij Rempel
3219374e8f5SOleksij Rempel /*
3229374e8f5SOleksij Rempel * We aren't using spi_write_then_read() because we need to be able
3239374e8f5SOleksij Rempel * to get hold of the effective_speed_hz from the xfer
3249374e8f5SOleksij Rempel */
3259374e8f5SOleksij Rempel ret = spi_sync(priv->spi, &msg);
3269374e8f5SOleksij Rempel if (ret) {
3279374e8f5SOleksij Rempel dev_err_ratelimited(&priv->spi->dev, "SPI transfer failed %pe\n",
3289374e8f5SOleksij Rempel ERR_PTR(ret));
329b617693aSOleksij Rempel goto free_bufs;
3309374e8f5SOleksij Rempel }
3319374e8f5SOleksij Rempel
3329374e8f5SOleksij Rempel if (effective_speed_hz)
3339374e8f5SOleksij Rempel *effective_speed_hz = xfer.effective_speed_hz;
3349374e8f5SOleksij Rempel
335b617693aSOleksij Rempel for (i = 0; i < max_count - count_skip; i++) {
336b617693aSOleksij Rempel val = tsc2046_adc_get_value(&rx_buf[count_skip + i]);
337b617693aSOleksij Rempel val_normalized += val;
338b617693aSOleksij Rempel }
339b617693aSOleksij Rempel
340b617693aSOleksij Rempel ret = DIV_ROUND_UP(val_normalized, max_count - count_skip);
341b617693aSOleksij Rempel
342b617693aSOleksij Rempel free_bufs:
343b617693aSOleksij Rempel kfree(rx_buf);
344b617693aSOleksij Rempel free_tx:
345b617693aSOleksij Rempel kfree(tx_buf);
346b617693aSOleksij Rempel
347b617693aSOleksij Rempel return ret;
3489374e8f5SOleksij Rempel }
3499374e8f5SOleksij Rempel
tsc2046_adc_group_set_layout(struct tsc2046_adc_priv * priv,unsigned int group,unsigned int ch_idx)3509374e8f5SOleksij Rempel static size_t tsc2046_adc_group_set_layout(struct tsc2046_adc_priv *priv,
3519374e8f5SOleksij Rempel unsigned int group,
3529374e8f5SOleksij Rempel unsigned int ch_idx)
3539374e8f5SOleksij Rempel {
3549374e8f5SOleksij Rempel struct tsc2046_adc_ch_cfg *ch = &priv->ch_cfg[ch_idx];
3559374e8f5SOleksij Rempel struct tsc2046_adc_group_layout *cur;
3569374e8f5SOleksij Rempel unsigned int max_count, count_skip;
3579374e8f5SOleksij Rempel unsigned int offset = 0;
3589374e8f5SOleksij Rempel
3599374e8f5SOleksij Rempel if (group)
3609374e8f5SOleksij Rempel offset = priv->l[group - 1].offset + priv->l[group - 1].count;
3619374e8f5SOleksij Rempel
3629374e8f5SOleksij Rempel count_skip = tsc2046_adc_time_to_count(priv, ch->settling_time_us);
3639374e8f5SOleksij Rempel max_count = count_skip + ch->oversampling_ratio;
3649374e8f5SOleksij Rempel
3659374e8f5SOleksij Rempel cur = &priv->l[group];
3669374e8f5SOleksij Rempel cur->offset = offset;
3679374e8f5SOleksij Rempel cur->count = max_count;
3689374e8f5SOleksij Rempel cur->skip = count_skip;
3699374e8f5SOleksij Rempel
3709374e8f5SOleksij Rempel return sizeof(*priv->tx) * max_count;
3719374e8f5SOleksij Rempel }
3729374e8f5SOleksij Rempel
tsc2046_adc_group_set_cmd(struct tsc2046_adc_priv * priv,unsigned int group,int ch_idx)3739374e8f5SOleksij Rempel static void tsc2046_adc_group_set_cmd(struct tsc2046_adc_priv *priv,
3749374e8f5SOleksij Rempel unsigned int group, int ch_idx)
3759374e8f5SOleksij Rempel {
3769374e8f5SOleksij Rempel struct tsc2046_adc_group_layout *l = &priv->l[group];
3779374e8f5SOleksij Rempel unsigned int i;
3789374e8f5SOleksij Rempel u8 cmd;
3799374e8f5SOleksij Rempel
3809374e8f5SOleksij Rempel /*
3819374e8f5SOleksij Rempel * Do not enable automatic power down on working samples. Otherwise the
3829374e8f5SOleksij Rempel * plates will never be completely charged.
3839374e8f5SOleksij Rempel */
3849374e8f5SOleksij Rempel cmd = tsc2046_adc_get_cmd(priv, ch_idx, true);
3859374e8f5SOleksij Rempel
3869374e8f5SOleksij Rempel for (i = 0; i < l->count - 1; i++)
3879374e8f5SOleksij Rempel priv->tx[l->offset + i].cmd = cmd;
3889374e8f5SOleksij Rempel
3899374e8f5SOleksij Rempel /* automatically power down on last sample */
3909374e8f5SOleksij Rempel priv->tx[l->offset + i].cmd = tsc2046_adc_get_cmd(priv, ch_idx, false);
3919374e8f5SOleksij Rempel }
3929374e8f5SOleksij Rempel
tsc2046_adc_get_val(struct tsc2046_adc_priv * priv,int group)3939374e8f5SOleksij Rempel static u16 tsc2046_adc_get_val(struct tsc2046_adc_priv *priv, int group)
3949374e8f5SOleksij Rempel {
3959374e8f5SOleksij Rempel struct tsc2046_adc_group_layout *l;
3969374e8f5SOleksij Rempel unsigned int val, val_normalized = 0;
3979374e8f5SOleksij Rempel int valid_count, i;
3989374e8f5SOleksij Rempel
3999374e8f5SOleksij Rempel l = &priv->l[group];
4009374e8f5SOleksij Rempel valid_count = l->count - l->skip;
4019374e8f5SOleksij Rempel
4029374e8f5SOleksij Rempel for (i = 0; i < valid_count; i++) {
4039374e8f5SOleksij Rempel val = tsc2046_adc_get_value(&priv->rx[l->offset + l->skip + i]);
4049374e8f5SOleksij Rempel val_normalized += val;
4059374e8f5SOleksij Rempel }
4069374e8f5SOleksij Rempel
4079374e8f5SOleksij Rempel return DIV_ROUND_UP(val_normalized, valid_count);
4089374e8f5SOleksij Rempel }
4099374e8f5SOleksij Rempel
tsc2046_adc_scan(struct iio_dev * indio_dev)4109374e8f5SOleksij Rempel static int tsc2046_adc_scan(struct iio_dev *indio_dev)
4119374e8f5SOleksij Rempel {
4129374e8f5SOleksij Rempel struct tsc2046_adc_priv *priv = iio_priv(indio_dev);
4139374e8f5SOleksij Rempel struct device *dev = &priv->spi->dev;
4149374e8f5SOleksij Rempel int group;
4159374e8f5SOleksij Rempel int ret;
4169374e8f5SOleksij Rempel
4179374e8f5SOleksij Rempel ret = spi_sync(priv->spi, &priv->msg);
4189374e8f5SOleksij Rempel if (ret < 0) {
4199374e8f5SOleksij Rempel dev_err_ratelimited(dev, "SPI transfer failed: %pe\n", ERR_PTR(ret));
4209374e8f5SOleksij Rempel return ret;
4219374e8f5SOleksij Rempel }
4229374e8f5SOleksij Rempel
4239374e8f5SOleksij Rempel for (group = 0; group < priv->groups; group++)
4249374e8f5SOleksij Rempel priv->scan_buf.data[group] = tsc2046_adc_get_val(priv, group);
4259374e8f5SOleksij Rempel
4269374e8f5SOleksij Rempel ret = iio_push_to_buffers_with_timestamp(indio_dev, &priv->scan_buf,
4279374e8f5SOleksij Rempel iio_get_time_ns(indio_dev));
4289374e8f5SOleksij Rempel /* If the consumer is kfifo, we may get a EBUSY here - ignore it. */
4299374e8f5SOleksij Rempel if (ret < 0 && ret != -EBUSY) {
4309374e8f5SOleksij Rempel dev_err_ratelimited(dev, "Failed to push scan buffer %pe\n",
4319374e8f5SOleksij Rempel ERR_PTR(ret));
4329374e8f5SOleksij Rempel
4339374e8f5SOleksij Rempel return ret;
4349374e8f5SOleksij Rempel }
4359374e8f5SOleksij Rempel
4369374e8f5SOleksij Rempel return 0;
4379374e8f5SOleksij Rempel }
4389374e8f5SOleksij Rempel
tsc2046_adc_trigger_handler(int irq,void * p)4399374e8f5SOleksij Rempel static irqreturn_t tsc2046_adc_trigger_handler(int irq, void *p)
4409374e8f5SOleksij Rempel {
4419374e8f5SOleksij Rempel struct iio_poll_func *pf = p;
4429374e8f5SOleksij Rempel struct iio_dev *indio_dev = pf->indio_dev;
4439374e8f5SOleksij Rempel struct tsc2046_adc_priv *priv = iio_priv(indio_dev);
4449374e8f5SOleksij Rempel
4459374e8f5SOleksij Rempel mutex_lock(&priv->slock);
4469374e8f5SOleksij Rempel tsc2046_adc_scan(indio_dev);
4479374e8f5SOleksij Rempel mutex_unlock(&priv->slock);
4489374e8f5SOleksij Rempel
4499374e8f5SOleksij Rempel iio_trigger_notify_done(indio_dev->trig);
4509374e8f5SOleksij Rempel
4519374e8f5SOleksij Rempel return IRQ_HANDLED;
4529374e8f5SOleksij Rempel }
4539374e8f5SOleksij Rempel
tsc2046_adc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long m)454b617693aSOleksij Rempel static int tsc2046_adc_read_raw(struct iio_dev *indio_dev,
455b617693aSOleksij Rempel struct iio_chan_spec const *chan,
456b617693aSOleksij Rempel int *val, int *val2, long m)
457b617693aSOleksij Rempel {
458b617693aSOleksij Rempel struct tsc2046_adc_priv *priv = iio_priv(indio_dev);
459b617693aSOleksij Rempel int ret;
460b617693aSOleksij Rempel
461b617693aSOleksij Rempel switch (m) {
462b617693aSOleksij Rempel case IIO_CHAN_INFO_RAW:
463b617693aSOleksij Rempel ret = tsc2046_adc_read_one(priv, chan->channel, NULL);
464b617693aSOleksij Rempel if (ret < 0)
465b617693aSOleksij Rempel return ret;
466b617693aSOleksij Rempel
467b617693aSOleksij Rempel *val = ret;
468b617693aSOleksij Rempel
469b617693aSOleksij Rempel return IIO_VAL_INT;
470b617693aSOleksij Rempel case IIO_CHAN_INFO_SCALE:
471b617693aSOleksij Rempel /*
472b617693aSOleksij Rempel * Note: the TSC2046 has internal voltage divider on the VBAT
473b617693aSOleksij Rempel * line. This divider can be influenced by external divider.
474b617693aSOleksij Rempel * So, it is better to use external voltage-divider driver
475b617693aSOleksij Rempel * instead, which is calculating complete chain.
476b617693aSOleksij Rempel */
477a616a6a1SOleksij Rempel *val = priv->vref_mv;
478b617693aSOleksij Rempel *val2 = chan->scan_type.realbits;
479b617693aSOleksij Rempel return IIO_VAL_FRACTIONAL_LOG2;
480b617693aSOleksij Rempel }
481b617693aSOleksij Rempel
482b617693aSOleksij Rempel return -EINVAL;
483b617693aSOleksij Rempel }
484b617693aSOleksij Rempel
tsc2046_adc_update_scan_mode(struct iio_dev * indio_dev,const unsigned long * active_scan_mask)4859374e8f5SOleksij Rempel static int tsc2046_adc_update_scan_mode(struct iio_dev *indio_dev,
4869374e8f5SOleksij Rempel const unsigned long *active_scan_mask)
4879374e8f5SOleksij Rempel {
4889374e8f5SOleksij Rempel struct tsc2046_adc_priv *priv = iio_priv(indio_dev);
4899374e8f5SOleksij Rempel unsigned int ch_idx, group = 0;
4909374e8f5SOleksij Rempel size_t size;
4919374e8f5SOleksij Rempel
4929374e8f5SOleksij Rempel mutex_lock(&priv->slock);
4939374e8f5SOleksij Rempel
4949374e8f5SOleksij Rempel size = 0;
495b7a78a8aSOleksij Rempel for_each_set_bit(ch_idx, active_scan_mask, ARRAY_SIZE(priv->l)) {
4969374e8f5SOleksij Rempel size += tsc2046_adc_group_set_layout(priv, group, ch_idx);
4979374e8f5SOleksij Rempel tsc2046_adc_group_set_cmd(priv, group, ch_idx);
4989374e8f5SOleksij Rempel group++;
4999374e8f5SOleksij Rempel }
5009374e8f5SOleksij Rempel
5019374e8f5SOleksij Rempel priv->groups = group;
5029374e8f5SOleksij Rempel priv->xfer.len = size;
5039374e8f5SOleksij Rempel priv->time_per_scan_us = size * 8 * priv->time_per_bit_ns / NSEC_PER_USEC;
5049374e8f5SOleksij Rempel
50569b31fd7SOleksij Rempel if (priv->scan_interval_us < priv->time_per_scan_us)
5069374e8f5SOleksij Rempel dev_warn(&priv->spi->dev, "The scan interval (%d) is less then calculated scan time (%d)\n",
5079374e8f5SOleksij Rempel priv->scan_interval_us, priv->time_per_scan_us);
5089374e8f5SOleksij Rempel
5099374e8f5SOleksij Rempel mutex_unlock(&priv->slock);
5109374e8f5SOleksij Rempel
5119374e8f5SOleksij Rempel return 0;
5129374e8f5SOleksij Rempel }
5139374e8f5SOleksij Rempel
5149374e8f5SOleksij Rempel static const struct iio_info tsc2046_adc_info = {
515b617693aSOleksij Rempel .read_raw = tsc2046_adc_read_raw,
5169374e8f5SOleksij Rempel .update_scan_mode = tsc2046_adc_update_scan_mode,
5179374e8f5SOleksij Rempel };
5189374e8f5SOleksij Rempel
tsc2046_adc_timer(struct hrtimer * hrtimer)51984e5d889SOleksij Rempel static enum hrtimer_restart tsc2046_adc_timer(struct hrtimer *hrtimer)
5209374e8f5SOleksij Rempel {
5219374e8f5SOleksij Rempel struct tsc2046_adc_priv *priv = container_of(hrtimer,
5229374e8f5SOleksij Rempel struct tsc2046_adc_priv,
5239374e8f5SOleksij Rempel trig_timer);
5249374e8f5SOleksij Rempel unsigned long flags;
5259374e8f5SOleksij Rempel
52684e5d889SOleksij Rempel /*
52784e5d889SOleksij Rempel * This state machine should address following challenges :
52884e5d889SOleksij Rempel * - the interrupt source is based on level shifter attached to the X
52984e5d889SOleksij Rempel * channel of ADC. It will change the state every time we switch
53084e5d889SOleksij Rempel * between channels. So, we need to disable IRQ if we do
53184e5d889SOleksij Rempel * iio_trigger_poll().
53284e5d889SOleksij Rempel * - we should do iio_trigger_poll() at some reduced sample rate
53384e5d889SOleksij Rempel * - we should still trigger for some amount of time after last
53484e5d889SOleksij Rempel * interrupt with enabled IRQ was processed.
53584e5d889SOleksij Rempel */
5369374e8f5SOleksij Rempel
53784e5d889SOleksij Rempel spin_lock_irqsave(&priv->state_lock, flags);
53884e5d889SOleksij Rempel switch (priv->state) {
53984e5d889SOleksij Rempel case TSC2046_STATE_ENABLE_IRQ:
54084e5d889SOleksij Rempel if (priv->poll_cnt < TI_TSC2046_POLL_CNT) {
54184e5d889SOleksij Rempel priv->poll_cnt++;
54284e5d889SOleksij Rempel hrtimer_start(&priv->trig_timer,
54384e5d889SOleksij Rempel ns_to_ktime(priv->scan_interval_us *
54484e5d889SOleksij Rempel NSEC_PER_USEC),
54584e5d889SOleksij Rempel HRTIMER_MODE_REL_SOFT);
54684e5d889SOleksij Rempel
54784e5d889SOleksij Rempel if (priv->poll_cnt >= TI_TSC2046_MIN_POLL_CNT) {
54884e5d889SOleksij Rempel priv->state = TSC2046_STATE_POLL_IRQ_DISABLE;
54984e5d889SOleksij Rempel enable_irq(priv->spi->irq);
55084e5d889SOleksij Rempel } else {
55184e5d889SOleksij Rempel priv->state = TSC2046_STATE_POLL;
55284e5d889SOleksij Rempel }
55384e5d889SOleksij Rempel } else {
55484e5d889SOleksij Rempel priv->state = TSC2046_STATE_STANDBY;
55584e5d889SOleksij Rempel enable_irq(priv->spi->irq);
55684e5d889SOleksij Rempel }
55784e5d889SOleksij Rempel break;
55884e5d889SOleksij Rempel case TSC2046_STATE_POLL_IRQ_DISABLE:
5599374e8f5SOleksij Rempel disable_irq_nosync(priv->spi->irq);
56084e5d889SOleksij Rempel fallthrough;
56184e5d889SOleksij Rempel case TSC2046_STATE_POLL:
56284e5d889SOleksij Rempel priv->state = TSC2046_STATE_ENABLE_IRQ;
56384e5d889SOleksij Rempel /* iio_trigger_poll() starts hrtimer */
5649374e8f5SOleksij Rempel iio_trigger_poll(priv->trig);
56584e5d889SOleksij Rempel break;
56684e5d889SOleksij Rempel case TSC2046_STATE_SHUTDOWN:
56784e5d889SOleksij Rempel break;
56884e5d889SOleksij Rempel case TSC2046_STATE_STANDBY:
56984e5d889SOleksij Rempel fallthrough;
57084e5d889SOleksij Rempel default:
57184e5d889SOleksij Rempel dev_warn(&priv->spi->dev, "Got unexpected state: %i\n",
57284e5d889SOleksij Rempel priv->state);
57384e5d889SOleksij Rempel break;
57484e5d889SOleksij Rempel }
57584e5d889SOleksij Rempel spin_unlock_irqrestore(&priv->state_lock, flags);
5769374e8f5SOleksij Rempel
5779374e8f5SOleksij Rempel return HRTIMER_NORESTART;
5789374e8f5SOleksij Rempel }
5799374e8f5SOleksij Rempel
tsc2046_adc_irq(int irq,void * dev_id)5809374e8f5SOleksij Rempel static irqreturn_t tsc2046_adc_irq(int irq, void *dev_id)
5819374e8f5SOleksij Rempel {
5829374e8f5SOleksij Rempel struct iio_dev *indio_dev = dev_id;
5839374e8f5SOleksij Rempel struct tsc2046_adc_priv *priv = iio_priv(indio_dev);
58484e5d889SOleksij Rempel unsigned long flags;
5859374e8f5SOleksij Rempel
5869374e8f5SOleksij Rempel hrtimer_try_to_cancel(&priv->trig_timer);
5879374e8f5SOleksij Rempel
58884e5d889SOleksij Rempel spin_lock_irqsave(&priv->state_lock, flags);
58984e5d889SOleksij Rempel if (priv->state != TSC2046_STATE_SHUTDOWN) {
59084e5d889SOleksij Rempel priv->state = TSC2046_STATE_ENABLE_IRQ;
59184e5d889SOleksij Rempel priv->poll_cnt = 0;
59284e5d889SOleksij Rempel
59384e5d889SOleksij Rempel /* iio_trigger_poll() starts hrtimer */
5949374e8f5SOleksij Rempel disable_irq_nosync(priv->spi->irq);
5959374e8f5SOleksij Rempel iio_trigger_poll(priv->trig);
59684e5d889SOleksij Rempel }
59784e5d889SOleksij Rempel spin_unlock_irqrestore(&priv->state_lock, flags);
5989374e8f5SOleksij Rempel
5999374e8f5SOleksij Rempel return IRQ_HANDLED;
6009374e8f5SOleksij Rempel }
6019374e8f5SOleksij Rempel
tsc2046_adc_reenable_trigger(struct iio_trigger * trig)6029374e8f5SOleksij Rempel static void tsc2046_adc_reenable_trigger(struct iio_trigger *trig)
6039374e8f5SOleksij Rempel {
6049374e8f5SOleksij Rempel struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
6059374e8f5SOleksij Rempel struct tsc2046_adc_priv *priv = iio_priv(indio_dev);
60684e5d889SOleksij Rempel ktime_t tim;
6079374e8f5SOleksij Rempel
6089374e8f5SOleksij Rempel /*
6099374e8f5SOleksij Rempel * We can sample it as fast as we can, but usually we do not need so
6109374e8f5SOleksij Rempel * many samples. Reduce the sample rate for default (touchscreen) use
6119374e8f5SOleksij Rempel * case.
6129374e8f5SOleksij Rempel */
61384e5d889SOleksij Rempel tim = ns_to_ktime((priv->scan_interval_us - priv->time_per_scan_us) *
61484e5d889SOleksij Rempel NSEC_PER_USEC);
61584e5d889SOleksij Rempel hrtimer_start(&priv->trig_timer, tim, HRTIMER_MODE_REL_SOFT);
6169374e8f5SOleksij Rempel }
6179374e8f5SOleksij Rempel
tsc2046_adc_set_trigger_state(struct iio_trigger * trig,bool enable)6189374e8f5SOleksij Rempel static int tsc2046_adc_set_trigger_state(struct iio_trigger *trig, bool enable)
6199374e8f5SOleksij Rempel {
6209374e8f5SOleksij Rempel struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
6219374e8f5SOleksij Rempel struct tsc2046_adc_priv *priv = iio_priv(indio_dev);
62284e5d889SOleksij Rempel unsigned long flags;
6239374e8f5SOleksij Rempel
6249374e8f5SOleksij Rempel if (enable) {
62584e5d889SOleksij Rempel spin_lock_irqsave(&priv->state_lock, flags);
62684e5d889SOleksij Rempel if (priv->state == TSC2046_STATE_SHUTDOWN) {
62784e5d889SOleksij Rempel priv->state = TSC2046_STATE_STANDBY;
6289374e8f5SOleksij Rempel enable_irq(priv->spi->irq);
62984e5d889SOleksij Rempel }
63084e5d889SOleksij Rempel spin_unlock_irqrestore(&priv->state_lock, flags);
6319374e8f5SOleksij Rempel } else {
63284e5d889SOleksij Rempel spin_lock_irqsave(&priv->state_lock, flags);
63384e5d889SOleksij Rempel
63484e5d889SOleksij Rempel if (priv->state == TSC2046_STATE_STANDBY ||
63584e5d889SOleksij Rempel priv->state == TSC2046_STATE_POLL_IRQ_DISABLE)
63684e5d889SOleksij Rempel disable_irq_nosync(priv->spi->irq);
63784e5d889SOleksij Rempel
63884e5d889SOleksij Rempel priv->state = TSC2046_STATE_SHUTDOWN;
63984e5d889SOleksij Rempel spin_unlock_irqrestore(&priv->state_lock, flags);
64084e5d889SOleksij Rempel
64184e5d889SOleksij Rempel hrtimer_cancel(&priv->trig_timer);
6429374e8f5SOleksij Rempel }
6439374e8f5SOleksij Rempel
6449374e8f5SOleksij Rempel return 0;
6459374e8f5SOleksij Rempel }
6469374e8f5SOleksij Rempel
6479374e8f5SOleksij Rempel static const struct iio_trigger_ops tsc2046_adc_trigger_ops = {
6489374e8f5SOleksij Rempel .set_trigger_state = tsc2046_adc_set_trigger_state,
6499374e8f5SOleksij Rempel .reenable = tsc2046_adc_reenable_trigger,
6509374e8f5SOleksij Rempel };
6519374e8f5SOleksij Rempel
tsc2046_adc_setup_spi_msg(struct tsc2046_adc_priv * priv)6529374e8f5SOleksij Rempel static int tsc2046_adc_setup_spi_msg(struct tsc2046_adc_priv *priv)
6539374e8f5SOleksij Rempel {
6549374e8f5SOleksij Rempel unsigned int ch_idx;
6559374e8f5SOleksij Rempel size_t size;
6569374e8f5SOleksij Rempel int ret;
6579374e8f5SOleksij Rempel
6589374e8f5SOleksij Rempel /*
6599374e8f5SOleksij Rempel * Make dummy read to set initial power state and get real SPI clock
6609374e8f5SOleksij Rempel * freq. It seems to be not important which channel is used for this
6619374e8f5SOleksij Rempel * case.
6629374e8f5SOleksij Rempel */
6639374e8f5SOleksij Rempel ret = tsc2046_adc_read_one(priv, TI_TSC2046_ADDR_TEMP0,
6649374e8f5SOleksij Rempel &priv->effective_speed_hz);
6659374e8f5SOleksij Rempel if (ret < 0)
6669374e8f5SOleksij Rempel return ret;
6679374e8f5SOleksij Rempel
6689374e8f5SOleksij Rempel /*
6699374e8f5SOleksij Rempel * In case SPI controller do not report effective_speed_hz, use
6709374e8f5SOleksij Rempel * configure value and hope it will match.
6719374e8f5SOleksij Rempel */
6729374e8f5SOleksij Rempel if (!priv->effective_speed_hz)
6739374e8f5SOleksij Rempel priv->effective_speed_hz = priv->spi->max_speed_hz;
6749374e8f5SOleksij Rempel
6759374e8f5SOleksij Rempel
6769374e8f5SOleksij Rempel priv->scan_interval_us = TI_TSC2046_SAMPLE_INTERVAL_US;
6779374e8f5SOleksij Rempel priv->time_per_bit_ns = DIV_ROUND_UP(NSEC_PER_SEC,
6789374e8f5SOleksij Rempel priv->effective_speed_hz);
6799374e8f5SOleksij Rempel
6809374e8f5SOleksij Rempel /*
6819374e8f5SOleksij Rempel * Calculate and allocate maximal size buffer if all channels are
6829374e8f5SOleksij Rempel * enabled.
6839374e8f5SOleksij Rempel */
6849374e8f5SOleksij Rempel size = 0;
685b7a78a8aSOleksij Rempel for (ch_idx = 0; ch_idx < ARRAY_SIZE(priv->l); ch_idx++)
6869374e8f5SOleksij Rempel size += tsc2046_adc_group_set_layout(priv, ch_idx, ch_idx);
6879374e8f5SOleksij Rempel
688576434fdSOleksij Rempel if (size > PAGE_SIZE) {
689576434fdSOleksij Rempel dev_err(&priv->spi->dev,
690576434fdSOleksij Rempel "Calculated scan buffer is too big. Try to reduce spi-max-frequency, settling-time-us or oversampling-ratio\n");
691576434fdSOleksij Rempel return -ENOSPC;
692576434fdSOleksij Rempel }
693576434fdSOleksij Rempel
6949374e8f5SOleksij Rempel priv->tx = devm_kzalloc(&priv->spi->dev, size, GFP_KERNEL);
6959374e8f5SOleksij Rempel if (!priv->tx)
6969374e8f5SOleksij Rempel return -ENOMEM;
6979374e8f5SOleksij Rempel
6989374e8f5SOleksij Rempel priv->rx = devm_kzalloc(&priv->spi->dev, size, GFP_KERNEL);
6999374e8f5SOleksij Rempel if (!priv->rx)
7009374e8f5SOleksij Rempel return -ENOMEM;
7019374e8f5SOleksij Rempel
7029374e8f5SOleksij Rempel priv->xfer.tx_buf = priv->tx;
7039374e8f5SOleksij Rempel priv->xfer.rx_buf = priv->rx;
7049374e8f5SOleksij Rempel priv->xfer.len = size;
7059374e8f5SOleksij Rempel spi_message_init_with_transfers(&priv->msg, &priv->xfer, 1);
7069374e8f5SOleksij Rempel
7079374e8f5SOleksij Rempel return 0;
7089374e8f5SOleksij Rempel }
7099374e8f5SOleksij Rempel
tsc2046_adc_parse_fwnode(struct tsc2046_adc_priv * priv)7109374e8f5SOleksij Rempel static void tsc2046_adc_parse_fwnode(struct tsc2046_adc_priv *priv)
7119374e8f5SOleksij Rempel {
7129374e8f5SOleksij Rempel struct fwnode_handle *child;
7139374e8f5SOleksij Rempel struct device *dev = &priv->spi->dev;
7149374e8f5SOleksij Rempel unsigned int i;
7159374e8f5SOleksij Rempel
7169374e8f5SOleksij Rempel for (i = 0; i < ARRAY_SIZE(priv->ch_cfg); i++) {
7179374e8f5SOleksij Rempel priv->ch_cfg[i].settling_time_us = 1;
7189374e8f5SOleksij Rempel priv->ch_cfg[i].oversampling_ratio = 1;
7199374e8f5SOleksij Rempel }
7209374e8f5SOleksij Rempel
7219374e8f5SOleksij Rempel device_for_each_child_node(dev, child) {
7229374e8f5SOleksij Rempel u32 stl, overs, reg;
7239374e8f5SOleksij Rempel int ret;
7249374e8f5SOleksij Rempel
7259374e8f5SOleksij Rempel ret = fwnode_property_read_u32(child, "reg", ®);
7269374e8f5SOleksij Rempel if (ret) {
7279374e8f5SOleksij Rempel dev_err(dev, "invalid reg on %pfw, err: %pe\n", child,
7289374e8f5SOleksij Rempel ERR_PTR(ret));
7299374e8f5SOleksij Rempel continue;
7309374e8f5SOleksij Rempel }
7319374e8f5SOleksij Rempel
7329374e8f5SOleksij Rempel if (reg >= ARRAY_SIZE(priv->ch_cfg)) {
7339374e8f5SOleksij Rempel dev_err(dev, "%pfw: Unsupported reg value: %i, max supported is: %zu.\n",
7349374e8f5SOleksij Rempel child, reg, ARRAY_SIZE(priv->ch_cfg));
7359374e8f5SOleksij Rempel continue;
7369374e8f5SOleksij Rempel }
7379374e8f5SOleksij Rempel
7389374e8f5SOleksij Rempel ret = fwnode_property_read_u32(child, "settling-time-us", &stl);
7399374e8f5SOleksij Rempel if (!ret)
7409374e8f5SOleksij Rempel priv->ch_cfg[reg].settling_time_us = stl;
7419374e8f5SOleksij Rempel
7429374e8f5SOleksij Rempel ret = fwnode_property_read_u32(child, "oversampling-ratio",
7439374e8f5SOleksij Rempel &overs);
7449374e8f5SOleksij Rempel if (!ret)
7459374e8f5SOleksij Rempel priv->ch_cfg[reg].oversampling_ratio = overs;
7469374e8f5SOleksij Rempel }
7479374e8f5SOleksij Rempel }
7489374e8f5SOleksij Rempel
tsc2046_adc_regulator_disable(void * data)749a616a6a1SOleksij Rempel static void tsc2046_adc_regulator_disable(void *data)
750a616a6a1SOleksij Rempel {
751a616a6a1SOleksij Rempel struct tsc2046_adc_priv *priv = data;
752a616a6a1SOleksij Rempel
753a616a6a1SOleksij Rempel regulator_disable(priv->vref_reg);
754a616a6a1SOleksij Rempel }
755a616a6a1SOleksij Rempel
tsc2046_adc_configure_regulator(struct tsc2046_adc_priv * priv)756a616a6a1SOleksij Rempel static int tsc2046_adc_configure_regulator(struct tsc2046_adc_priv *priv)
757a616a6a1SOleksij Rempel {
758a616a6a1SOleksij Rempel struct device *dev = &priv->spi->dev;
759a616a6a1SOleksij Rempel int ret;
760a616a6a1SOleksij Rempel
761a616a6a1SOleksij Rempel priv->vref_reg = devm_regulator_get_optional(dev, "vref");
762a616a6a1SOleksij Rempel if (IS_ERR(priv->vref_reg)) {
763a616a6a1SOleksij Rempel /* If regulator exists but can't be get, return an error */
764a616a6a1SOleksij Rempel if (PTR_ERR(priv->vref_reg) != -ENODEV)
765a616a6a1SOleksij Rempel return PTR_ERR(priv->vref_reg);
766a616a6a1SOleksij Rempel priv->vref_reg = NULL;
767a616a6a1SOleksij Rempel }
768a616a6a1SOleksij Rempel if (!priv->vref_reg) {
769a616a6a1SOleksij Rempel /* Use internal reference */
770a616a6a1SOleksij Rempel priv->vref_mv = TI_TSC2046_INT_VREF;
771a616a6a1SOleksij Rempel return 0;
772a616a6a1SOleksij Rempel }
773a616a6a1SOleksij Rempel
774a616a6a1SOleksij Rempel ret = regulator_enable(priv->vref_reg);
775a616a6a1SOleksij Rempel if (ret)
776a616a6a1SOleksij Rempel return ret;
777a616a6a1SOleksij Rempel
778a616a6a1SOleksij Rempel ret = devm_add_action_or_reset(dev, tsc2046_adc_regulator_disable,
779a616a6a1SOleksij Rempel priv);
780a616a6a1SOleksij Rempel if (ret)
781a616a6a1SOleksij Rempel return ret;
782a616a6a1SOleksij Rempel
783a616a6a1SOleksij Rempel ret = regulator_get_voltage(priv->vref_reg);
784a616a6a1SOleksij Rempel if (ret < 0)
785a616a6a1SOleksij Rempel return ret;
786a616a6a1SOleksij Rempel
787a616a6a1SOleksij Rempel priv->vref_mv = ret / MILLI;
788a616a6a1SOleksij Rempel
789a616a6a1SOleksij Rempel return 0;
790a616a6a1SOleksij Rempel }
791a616a6a1SOleksij Rempel
tsc2046_adc_probe(struct spi_device * spi)7929374e8f5SOleksij Rempel static int tsc2046_adc_probe(struct spi_device *spi)
7939374e8f5SOleksij Rempel {
7949374e8f5SOleksij Rempel const struct tsc2046_adc_dcfg *dcfg;
7959374e8f5SOleksij Rempel struct device *dev = &spi->dev;
7969374e8f5SOleksij Rempel struct tsc2046_adc_priv *priv;
7979374e8f5SOleksij Rempel struct iio_dev *indio_dev;
7989374e8f5SOleksij Rempel struct iio_trigger *trig;
7999374e8f5SOleksij Rempel int ret;
8009374e8f5SOleksij Rempel
8019374e8f5SOleksij Rempel if (spi->max_speed_hz > TI_TSC2046_MAX_CLK_FREQ) {
8029374e8f5SOleksij Rempel dev_err(dev, "SPI max_speed_hz is too high: %d Hz. Max supported freq is %zu Hz\n",
8039374e8f5SOleksij Rempel spi->max_speed_hz, TI_TSC2046_MAX_CLK_FREQ);
8049374e8f5SOleksij Rempel return -EINVAL;
8059374e8f5SOleksij Rempel }
8069374e8f5SOleksij Rempel
8079374e8f5SOleksij Rempel dcfg = device_get_match_data(dev);
808*3f8dd0a7SOleksij Rempel if (!dcfg) {
809*3f8dd0a7SOleksij Rempel const struct spi_device_id *id = spi_get_device_id(spi);
810*3f8dd0a7SOleksij Rempel
811*3f8dd0a7SOleksij Rempel dcfg = (const struct tsc2046_adc_dcfg *)id->driver_data;
812*3f8dd0a7SOleksij Rempel }
8139374e8f5SOleksij Rempel if (!dcfg)
8149374e8f5SOleksij Rempel return -EINVAL;
8159374e8f5SOleksij Rempel
8169374e8f5SOleksij Rempel spi->bits_per_word = 8;
8179374e8f5SOleksij Rempel spi->mode &= ~SPI_MODE_X_MASK;
8189374e8f5SOleksij Rempel spi->mode |= SPI_MODE_0;
8199374e8f5SOleksij Rempel ret = spi_setup(spi);
8209374e8f5SOleksij Rempel if (ret < 0)
8219374e8f5SOleksij Rempel return dev_err_probe(dev, ret, "Error in SPI setup\n");
8229374e8f5SOleksij Rempel
8239374e8f5SOleksij Rempel indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
8249374e8f5SOleksij Rempel if (!indio_dev)
8259374e8f5SOleksij Rempel return -ENOMEM;
8269374e8f5SOleksij Rempel
8279374e8f5SOleksij Rempel priv = iio_priv(indio_dev);
8289374e8f5SOleksij Rempel priv->dcfg = dcfg;
8299374e8f5SOleksij Rempel
8309374e8f5SOleksij Rempel priv->spi = spi;
8319374e8f5SOleksij Rempel
8329374e8f5SOleksij Rempel indio_dev->name = TI_TSC2046_NAME;
833338222d8SMarcus Folkesson indio_dev->modes = INDIO_DIRECT_MODE;
8349374e8f5SOleksij Rempel indio_dev->channels = dcfg->channels;
8359374e8f5SOleksij Rempel indio_dev->num_channels = dcfg->num_channels;
8369374e8f5SOleksij Rempel indio_dev->info = &tsc2046_adc_info;
8379374e8f5SOleksij Rempel
838a616a6a1SOleksij Rempel ret = tsc2046_adc_configure_regulator(priv);
839a616a6a1SOleksij Rempel if (ret)
840a616a6a1SOleksij Rempel return ret;
841a616a6a1SOleksij Rempel
8429374e8f5SOleksij Rempel tsc2046_adc_parse_fwnode(priv);
8439374e8f5SOleksij Rempel
8449374e8f5SOleksij Rempel ret = tsc2046_adc_setup_spi_msg(priv);
8459374e8f5SOleksij Rempel if (ret)
8469374e8f5SOleksij Rempel return ret;
8479374e8f5SOleksij Rempel
8489374e8f5SOleksij Rempel mutex_init(&priv->slock);
8499374e8f5SOleksij Rempel
8509374e8f5SOleksij Rempel ret = devm_request_irq(dev, spi->irq, &tsc2046_adc_irq,
8519374e8f5SOleksij Rempel IRQF_NO_AUTOEN, indio_dev->name, indio_dev);
8529374e8f5SOleksij Rempel if (ret)
8539374e8f5SOleksij Rempel return ret;
8549374e8f5SOleksij Rempel
8559374e8f5SOleksij Rempel trig = devm_iio_trigger_alloc(dev, "touchscreen-%s", indio_dev->name);
8569374e8f5SOleksij Rempel if (!trig)
8579374e8f5SOleksij Rempel return -ENOMEM;
8589374e8f5SOleksij Rempel
8599374e8f5SOleksij Rempel priv->trig = trig;
8609374e8f5SOleksij Rempel iio_trigger_set_drvdata(trig, indio_dev);
8619374e8f5SOleksij Rempel trig->ops = &tsc2046_adc_trigger_ops;
8629374e8f5SOleksij Rempel
86384e5d889SOleksij Rempel spin_lock_init(&priv->state_lock);
86484e5d889SOleksij Rempel priv->state = TSC2046_STATE_SHUTDOWN;
8659374e8f5SOleksij Rempel hrtimer_init(&priv->trig_timer, CLOCK_MONOTONIC,
8669374e8f5SOleksij Rempel HRTIMER_MODE_REL_SOFT);
86784e5d889SOleksij Rempel priv->trig_timer.function = tsc2046_adc_timer;
8689374e8f5SOleksij Rempel
8699374e8f5SOleksij Rempel ret = devm_iio_trigger_register(dev, trig);
8709374e8f5SOleksij Rempel if (ret) {
8719374e8f5SOleksij Rempel dev_err(dev, "failed to register trigger\n");
8729374e8f5SOleksij Rempel return ret;
8739374e8f5SOleksij Rempel }
8749374e8f5SOleksij Rempel
8759374e8f5SOleksij Rempel ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
8769374e8f5SOleksij Rempel &tsc2046_adc_trigger_handler, NULL);
8779374e8f5SOleksij Rempel if (ret) {
8789374e8f5SOleksij Rempel dev_err(dev, "Failed to setup triggered buffer\n");
8799374e8f5SOleksij Rempel return ret;
8809374e8f5SOleksij Rempel }
8819374e8f5SOleksij Rempel
8829374e8f5SOleksij Rempel /* set default trigger */
8839374e8f5SOleksij Rempel indio_dev->trig = iio_trigger_get(priv->trig);
8849374e8f5SOleksij Rempel
8859374e8f5SOleksij Rempel return devm_iio_device_register(dev, indio_dev);
8869374e8f5SOleksij Rempel }
8879374e8f5SOleksij Rempel
8889374e8f5SOleksij Rempel static const struct of_device_id ads7950_of_table[] = {
8899374e8f5SOleksij Rempel { .compatible = "ti,tsc2046e-adc", .data = &tsc2046_adc_dcfg_tsc2046e },
8909374e8f5SOleksij Rempel { }
8919374e8f5SOleksij Rempel };
8929374e8f5SOleksij Rempel MODULE_DEVICE_TABLE(of, ads7950_of_table);
8939374e8f5SOleksij Rempel
894*3f8dd0a7SOleksij Rempel static const struct spi_device_id tsc2046_adc_spi_ids[] = {
895*3f8dd0a7SOleksij Rempel { "tsc2046e-adc", (unsigned long)&tsc2046_adc_dcfg_tsc2046e },
896*3f8dd0a7SOleksij Rempel { }
897*3f8dd0a7SOleksij Rempel };
898*3f8dd0a7SOleksij Rempel MODULE_DEVICE_TABLE(spi, tsc2046_adc_spi_ids);
899*3f8dd0a7SOleksij Rempel
9009374e8f5SOleksij Rempel static struct spi_driver tsc2046_adc_driver = {
9019374e8f5SOleksij Rempel .driver = {
9029374e8f5SOleksij Rempel .name = "tsc2046",
9039374e8f5SOleksij Rempel .of_match_table = ads7950_of_table,
9049374e8f5SOleksij Rempel },
905*3f8dd0a7SOleksij Rempel .id_table = tsc2046_adc_spi_ids,
9069374e8f5SOleksij Rempel .probe = tsc2046_adc_probe,
9079374e8f5SOleksij Rempel };
9089374e8f5SOleksij Rempel module_spi_driver(tsc2046_adc_driver);
9099374e8f5SOleksij Rempel
9109374e8f5SOleksij Rempel MODULE_AUTHOR("Oleksij Rempel <kernel@pengutronix.de>");
9119374e8f5SOleksij Rempel MODULE_DESCRIPTION("TI TSC2046 ADC");
9129374e8f5SOleksij Rempel MODULE_LICENSE("GPL v2");
913