cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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qt1050.c (15027B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 *  Microchip AT42QT1050 QTouch Sensor Controller
      4 *
      5 *  Copyright (C) 2019 Pengutronix, Marco Felsch <kernel@pengutronix.de>
      6 *
      7 *  Base on AT42QT1070 driver by:
      8 *  Bo Shen <voice.shen@atmel.com>
      9 *  Copyright (C) 2011 Atmel
     10 */
     11
     12#include <linux/delay.h>
     13#include <linux/i2c.h>
     14#include <linux/input.h>
     15#include <linux/interrupt.h>
     16#include <linux/kernel.h>
     17#include <linux/log2.h>
     18#include <linux/module.h>
     19#include <linux/of.h>
     20#include <linux/regmap.h>
     21
     22/* Chip ID */
     23#define QT1050_CHIP_ID		0x00
     24#define QT1050_CHIP_ID_VER	0x46
     25
     26/* Firmware version */
     27#define QT1050_FW_VERSION	0x01
     28
     29/* Detection status */
     30#define QT1050_DET_STATUS	0x02
     31
     32/* Key status */
     33#define QT1050_KEY_STATUS	0x03
     34
     35/* Key Signals */
     36#define QT1050_KEY_SIGNAL_0_MSB	0x06
     37#define QT1050_KEY_SIGNAL_0_LSB	0x07
     38#define QT1050_KEY_SIGNAL_1_MSB	0x08
     39#define QT1050_KEY_SIGNAL_1_LSB	0x09
     40#define QT1050_KEY_SIGNAL_2_MSB	0x0c
     41#define QT1050_KEY_SIGNAL_2_LSB	0x0d
     42#define QT1050_KEY_SIGNAL_3_MSB	0x0e
     43#define QT1050_KEY_SIGNAL_3_LSB	0x0f
     44#define QT1050_KEY_SIGNAL_4_MSB	0x10
     45#define QT1050_KEY_SIGNAL_4_LSB	0x11
     46
     47/* Reference data */
     48#define QT1050_REF_DATA_0_MSB	0x14
     49#define QT1050_REF_DATA_0_LSB	0x15
     50#define QT1050_REF_DATA_1_MSB	0x16
     51#define QT1050_REF_DATA_1_LSB	0x17
     52#define QT1050_REF_DATA_2_MSB	0x1a
     53#define QT1050_REF_DATA_2_LSB	0x1b
     54#define QT1050_REF_DATA_3_MSB	0x1c
     55#define QT1050_REF_DATA_3_LSB	0x1d
     56#define QT1050_REF_DATA_4_MSB	0x1e
     57#define QT1050_REF_DATA_4_LSB	0x1f
     58
     59/* Negative threshold level */
     60#define QT1050_NTHR_0		0x21
     61#define QT1050_NTHR_1		0x22
     62#define QT1050_NTHR_2		0x24
     63#define QT1050_NTHR_3		0x25
     64#define QT1050_NTHR_4		0x26
     65
     66/* Pulse / Scale  */
     67#define QT1050_PULSE_SCALE_0	0x28
     68#define QT1050_PULSE_SCALE_1	0x29
     69#define QT1050_PULSE_SCALE_2	0x2b
     70#define QT1050_PULSE_SCALE_3	0x2c
     71#define QT1050_PULSE_SCALE_4	0x2d
     72
     73/* Detection integrator counter / AKS */
     74#define QT1050_DI_AKS_0		0x2f
     75#define QT1050_DI_AKS_1		0x30
     76#define QT1050_DI_AKS_2		0x32
     77#define QT1050_DI_AKS_3		0x33
     78#define QT1050_DI_AKS_4		0x34
     79
     80/* Charge Share Delay */
     81#define QT1050_CSD_0		0x36
     82#define QT1050_CSD_1		0x37
     83#define QT1050_CSD_2		0x39
     84#define QT1050_CSD_3		0x3a
     85#define QT1050_CSD_4		0x3b
     86
     87/* Low Power Mode */
     88#define QT1050_LPMODE		0x3d
     89
     90/* Calibration and Reset */
     91#define QT1050_RES_CAL		0x3f
     92#define QT1050_RES_CAL_RESET		BIT(7)
     93#define QT1050_RES_CAL_CALIBRATE	BIT(1)
     94
     95#define QT1050_MAX_KEYS		5
     96#define QT1050_RESET_TIME	255
     97
     98struct qt1050_key_regs {
     99	unsigned int nthr;
    100	unsigned int pulse_scale;
    101	unsigned int di_aks;
    102	unsigned int csd;
    103};
    104
    105struct qt1050_key {
    106	u32 num;
    107	u32 charge_delay;
    108	u32 thr_cnt;
    109	u32 samples;
    110	u32 scale;
    111	u32 keycode;
    112};
    113
    114struct qt1050_priv {
    115	struct i2c_client	*client;
    116	struct input_dev	*input;
    117	struct regmap		*regmap;
    118	struct qt1050_key	keys[QT1050_MAX_KEYS];
    119	unsigned short		keycodes[QT1050_MAX_KEYS];
    120	u8			reg_keys;
    121	u8			last_keys;
    122};
    123
    124static const struct qt1050_key_regs qt1050_key_regs_data[] = {
    125	{
    126		.nthr = QT1050_NTHR_0,
    127		.pulse_scale = QT1050_PULSE_SCALE_0,
    128		.di_aks = QT1050_DI_AKS_0,
    129		.csd = QT1050_CSD_0,
    130	}, {
    131		.nthr = QT1050_NTHR_1,
    132		.pulse_scale = QT1050_PULSE_SCALE_1,
    133		.di_aks = QT1050_DI_AKS_1,
    134		.csd = QT1050_CSD_1,
    135	}, {
    136		.nthr = QT1050_NTHR_2,
    137		.pulse_scale = QT1050_PULSE_SCALE_2,
    138		.di_aks = QT1050_DI_AKS_2,
    139		.csd = QT1050_CSD_2,
    140	}, {
    141		.nthr = QT1050_NTHR_3,
    142		.pulse_scale = QT1050_PULSE_SCALE_3,
    143		.di_aks = QT1050_DI_AKS_3,
    144		.csd = QT1050_CSD_3,
    145	}, {
    146		.nthr = QT1050_NTHR_4,
    147		.pulse_scale = QT1050_PULSE_SCALE_4,
    148		.di_aks = QT1050_DI_AKS_4,
    149		.csd = QT1050_CSD_4,
    150	}
    151};
    152
    153static bool qt1050_volatile_reg(struct device *dev, unsigned int reg)
    154{
    155	switch (reg) {
    156	case QT1050_DET_STATUS:
    157	case QT1050_KEY_STATUS:
    158	case QT1050_KEY_SIGNAL_0_MSB:
    159	case QT1050_KEY_SIGNAL_0_LSB:
    160	case QT1050_KEY_SIGNAL_1_MSB:
    161	case QT1050_KEY_SIGNAL_1_LSB:
    162	case QT1050_KEY_SIGNAL_2_MSB:
    163	case QT1050_KEY_SIGNAL_2_LSB:
    164	case QT1050_KEY_SIGNAL_3_MSB:
    165	case QT1050_KEY_SIGNAL_3_LSB:
    166	case QT1050_KEY_SIGNAL_4_MSB:
    167	case QT1050_KEY_SIGNAL_4_LSB:
    168		return true;
    169	default:
    170		return false;
    171	}
    172}
    173
    174static const struct regmap_range qt1050_readable_ranges[] = {
    175	regmap_reg_range(QT1050_CHIP_ID, QT1050_KEY_STATUS),
    176	regmap_reg_range(QT1050_KEY_SIGNAL_0_MSB, QT1050_KEY_SIGNAL_1_LSB),
    177	regmap_reg_range(QT1050_KEY_SIGNAL_2_MSB, QT1050_KEY_SIGNAL_4_LSB),
    178	regmap_reg_range(QT1050_REF_DATA_0_MSB, QT1050_REF_DATA_1_LSB),
    179	regmap_reg_range(QT1050_REF_DATA_2_MSB, QT1050_REF_DATA_4_LSB),
    180	regmap_reg_range(QT1050_NTHR_0, QT1050_NTHR_1),
    181	regmap_reg_range(QT1050_NTHR_2, QT1050_NTHR_4),
    182	regmap_reg_range(QT1050_PULSE_SCALE_0, QT1050_PULSE_SCALE_1),
    183	regmap_reg_range(QT1050_PULSE_SCALE_2, QT1050_PULSE_SCALE_4),
    184	regmap_reg_range(QT1050_DI_AKS_0, QT1050_DI_AKS_1),
    185	regmap_reg_range(QT1050_DI_AKS_2, QT1050_DI_AKS_4),
    186	regmap_reg_range(QT1050_CSD_0, QT1050_CSD_1),
    187	regmap_reg_range(QT1050_CSD_2, QT1050_RES_CAL),
    188};
    189
    190static const struct regmap_access_table qt1050_readable_table = {
    191	.yes_ranges = qt1050_readable_ranges,
    192	.n_yes_ranges = ARRAY_SIZE(qt1050_readable_ranges),
    193};
    194
    195static const struct regmap_range qt1050_writeable_ranges[] = {
    196	regmap_reg_range(QT1050_NTHR_0, QT1050_NTHR_1),
    197	regmap_reg_range(QT1050_NTHR_2, QT1050_NTHR_4),
    198	regmap_reg_range(QT1050_PULSE_SCALE_0, QT1050_PULSE_SCALE_1),
    199	regmap_reg_range(QT1050_PULSE_SCALE_2, QT1050_PULSE_SCALE_4),
    200	regmap_reg_range(QT1050_DI_AKS_0, QT1050_DI_AKS_1),
    201	regmap_reg_range(QT1050_DI_AKS_2, QT1050_DI_AKS_4),
    202	regmap_reg_range(QT1050_CSD_0, QT1050_CSD_1),
    203	regmap_reg_range(QT1050_CSD_2, QT1050_RES_CAL),
    204};
    205
    206static const struct regmap_access_table qt1050_writeable_table = {
    207	.yes_ranges = qt1050_writeable_ranges,
    208	.n_yes_ranges = ARRAY_SIZE(qt1050_writeable_ranges),
    209};
    210
    211static struct regmap_config qt1050_regmap_config = {
    212	.reg_bits = 8,
    213	.val_bits = 8,
    214	.max_register = QT1050_RES_CAL,
    215
    216	.cache_type = REGCACHE_RBTREE,
    217
    218	.wr_table = &qt1050_writeable_table,
    219	.rd_table = &qt1050_readable_table,
    220	.volatile_reg = qt1050_volatile_reg,
    221};
    222
    223static bool qt1050_identify(struct qt1050_priv *ts)
    224{
    225	unsigned int val;
    226	int err;
    227
    228	/* Read Chip ID */
    229	regmap_read(ts->regmap, QT1050_CHIP_ID, &val);
    230	if (val != QT1050_CHIP_ID_VER) {
    231		dev_err(&ts->client->dev, "ID %d not supported\n", val);
    232		return false;
    233	}
    234
    235	/* Read firmware version */
    236	err = regmap_read(ts->regmap, QT1050_FW_VERSION, &val);
    237	if (err) {
    238		dev_err(&ts->client->dev, "could not read the firmware version\n");
    239		return false;
    240	}
    241
    242	dev_info(&ts->client->dev, "AT42QT1050 firmware version %1d.%1d\n",
    243		 val >> 4, val & 0xf);
    244
    245	return true;
    246}
    247
    248static irqreturn_t qt1050_irq_threaded(int irq, void *dev_id)
    249{
    250	struct qt1050_priv *ts = dev_id;
    251	struct input_dev *input = ts->input;
    252	unsigned long new_keys, changed;
    253	unsigned int val;
    254	int i, err;
    255
    256	/* Read the detected status register, thus clearing interrupt */
    257	err = regmap_read(ts->regmap, QT1050_DET_STATUS, &val);
    258	if (err) {
    259		dev_err(&ts->client->dev, "Fail to read detection status: %d\n",
    260			err);
    261		return IRQ_NONE;
    262	}
    263
    264	/* Read which key changed, keys are not continuous */
    265	err = regmap_read(ts->regmap, QT1050_KEY_STATUS, &val);
    266	if (err) {
    267		dev_err(&ts->client->dev,
    268			"Fail to determine the key status: %d\n", err);
    269		return IRQ_NONE;
    270	}
    271	new_keys = (val & 0x70) >> 2 | (val & 0x6) >> 1;
    272	changed = ts->last_keys ^ new_keys;
    273	/* Report registered keys only */
    274	changed &= ts->reg_keys;
    275
    276	for_each_set_bit(i, &changed, QT1050_MAX_KEYS)
    277		input_report_key(input, ts->keys[i].keycode,
    278				 test_bit(i, &new_keys));
    279
    280	ts->last_keys = new_keys;
    281	input_sync(input);
    282
    283	return IRQ_HANDLED;
    284}
    285
    286static const struct qt1050_key_regs *qt1050_get_key_regs(int key_num)
    287{
    288	return &qt1050_key_regs_data[key_num];
    289}
    290
    291static int qt1050_set_key(struct regmap *map, int number, int on)
    292{
    293	const struct qt1050_key_regs *key_regs;
    294
    295	key_regs = qt1050_get_key_regs(number);
    296
    297	return regmap_update_bits(map, key_regs->di_aks, 0xfc,
    298				  on ? BIT(4) : 0x00);
    299}
    300
    301static int qt1050_apply_fw_data(struct qt1050_priv *ts)
    302{
    303	struct regmap *map = ts->regmap;
    304	struct qt1050_key *button = &ts->keys[0];
    305	const struct qt1050_key_regs *key_regs;
    306	int i, err;
    307
    308	/* Disable all keys and enable only the specified ones */
    309	for (i = 0; i < QT1050_MAX_KEYS; i++) {
    310		err = qt1050_set_key(map, i, 0);
    311		if (err)
    312			return err;
    313	}
    314
    315	for (i = 0; i < QT1050_MAX_KEYS; i++, button++) {
    316		/* Keep KEY_RESERVED keys off */
    317		if (button->keycode == KEY_RESERVED)
    318			continue;
    319
    320		err = qt1050_set_key(map, button->num, 1);
    321		if (err)
    322			return err;
    323
    324		key_regs = qt1050_get_key_regs(button->num);
    325
    326		err = regmap_write(map, key_regs->pulse_scale,
    327				   (button->samples << 4) | (button->scale));
    328		if (err)
    329			return err;
    330		err = regmap_write(map, key_regs->csd, button->charge_delay);
    331		if (err)
    332			return err;
    333		err = regmap_write(map, key_regs->nthr, button->thr_cnt);
    334		if (err)
    335			return err;
    336	}
    337
    338	return 0;
    339}
    340
    341static int qt1050_parse_fw(struct qt1050_priv *ts)
    342{
    343	struct device *dev = &ts->client->dev;
    344	struct fwnode_handle *child;
    345	int nbuttons;
    346
    347	nbuttons = device_get_child_node_count(dev);
    348	if (nbuttons == 0 || nbuttons > QT1050_MAX_KEYS)
    349		return -ENODEV;
    350
    351	device_for_each_child_node(dev, child) {
    352		struct qt1050_key button;
    353
    354		/* Required properties */
    355		if (fwnode_property_read_u32(child, "linux,code",
    356					     &button.keycode)) {
    357			dev_err(dev, "Button without keycode\n");
    358			goto err;
    359		}
    360		if (button.keycode >= KEY_MAX) {
    361			dev_err(dev, "Invalid keycode 0x%x\n",
    362				button.keycode);
    363			goto err;
    364		}
    365
    366		if (fwnode_property_read_u32(child, "reg",
    367					     &button.num)) {
    368			dev_err(dev, "Button without pad number\n");
    369			goto err;
    370		}
    371		if (button.num < 0 || button.num > QT1050_MAX_KEYS - 1)
    372			goto err;
    373
    374		ts->reg_keys |= BIT(button.num);
    375
    376		/* Optional properties */
    377		if (fwnode_property_read_u32(child,
    378					     "microchip,pre-charge-time-ns",
    379					     &button.charge_delay)) {
    380			button.charge_delay = 0;
    381		} else {
    382			if (button.charge_delay % 2500 == 0)
    383				button.charge_delay =
    384					button.charge_delay / 2500;
    385			else
    386				button.charge_delay = 0;
    387		}
    388
    389		if (fwnode_property_read_u32(child, "microchip,average-samples",
    390					 &button.samples)) {
    391			button.samples = 0;
    392		} else {
    393			if (is_power_of_2(button.samples))
    394				button.samples = ilog2(button.samples);
    395			else
    396				button.samples = 0;
    397		}
    398
    399		if (fwnode_property_read_u32(child, "microchip,average-scaling",
    400					     &button.scale)) {
    401			button.scale = 0;
    402		} else {
    403			if (is_power_of_2(button.scale))
    404				button.scale = ilog2(button.scale);
    405			else
    406				button.scale = 0;
    407
    408		}
    409
    410		if (fwnode_property_read_u32(child, "microchip,threshold",
    411					 &button.thr_cnt)) {
    412			button.thr_cnt = 20;
    413		} else {
    414			if (button.thr_cnt > 255)
    415				button.thr_cnt = 20;
    416		}
    417
    418		ts->keys[button.num] = button;
    419	}
    420
    421	return 0;
    422
    423err:
    424	fwnode_handle_put(child);
    425	return -EINVAL;
    426}
    427
    428static int qt1050_probe(struct i2c_client *client)
    429{
    430	struct qt1050_priv *ts;
    431	struct input_dev *input;
    432	struct device *dev = &client->dev;
    433	struct regmap *map;
    434	unsigned int status, i;
    435	int err;
    436
    437	/* Check basic functionality */
    438	err = i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE);
    439	if (!err) {
    440		dev_err(&client->dev, "%s adapter not supported\n",
    441			dev_driver_string(&client->adapter->dev));
    442		return -ENODEV;
    443	}
    444
    445	if (!client->irq) {
    446		dev_err(dev, "assign a irq line to this device\n");
    447		return -EINVAL;
    448	}
    449
    450	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
    451	if (!ts)
    452		return -ENOMEM;
    453
    454	input = devm_input_allocate_device(dev);
    455	if (!input)
    456		return -ENOMEM;
    457
    458	map = devm_regmap_init_i2c(client, &qt1050_regmap_config);
    459	if (IS_ERR(map))
    460		return PTR_ERR(map);
    461
    462	ts->client = client;
    463	ts->input = input;
    464	ts->regmap = map;
    465
    466	i2c_set_clientdata(client, ts);
    467
    468	/* Identify the qt1050 chip */
    469	if (!qt1050_identify(ts))
    470		return -ENODEV;
    471
    472	/* Get pdata */
    473	err = qt1050_parse_fw(ts);
    474	if (err) {
    475		dev_err(dev, "Failed to parse firmware: %d\n", err);
    476		return err;
    477	}
    478
    479	input->name = "AT42QT1050 QTouch Sensor";
    480	input->dev.parent = &client->dev;
    481	input->id.bustype = BUS_I2C;
    482
    483	/* Add the keycode */
    484	input->keycode = ts->keycodes;
    485	input->keycodesize = sizeof(ts->keycodes[0]);
    486	input->keycodemax = QT1050_MAX_KEYS;
    487
    488	__set_bit(EV_KEY, input->evbit);
    489	for (i = 0; i < QT1050_MAX_KEYS; i++) {
    490		ts->keycodes[i] = ts->keys[i].keycode;
    491		__set_bit(ts->keycodes[i], input->keybit);
    492	}
    493
    494	/* Trigger re-calibration */
    495	err = regmap_update_bits(ts->regmap, QT1050_RES_CAL, 0x7f,
    496				 QT1050_RES_CAL_CALIBRATE);
    497	if (err) {
    498		dev_err(dev, "Trigger calibration failed: %d\n", err);
    499		return err;
    500	}
    501	err = regmap_read_poll_timeout(ts->regmap, QT1050_DET_STATUS, status,
    502				 status >> 7 == 1, 10000, 200000);
    503	if (err) {
    504		dev_err(dev, "Calibration failed: %d\n", err);
    505		return err;
    506	}
    507
    508	/* Soft reset to set defaults */
    509	err = regmap_update_bits(ts->regmap, QT1050_RES_CAL,
    510				 QT1050_RES_CAL_RESET, QT1050_RES_CAL_RESET);
    511	if (err) {
    512		dev_err(dev, "Trigger soft reset failed: %d\n", err);
    513		return err;
    514	}
    515	msleep(QT1050_RESET_TIME);
    516
    517	/* Set pdata */
    518	err = qt1050_apply_fw_data(ts);
    519	if (err) {
    520		dev_err(dev, "Failed to set firmware data: %d\n", err);
    521		return err;
    522	}
    523
    524	err = devm_request_threaded_irq(dev, client->irq, NULL,
    525					qt1050_irq_threaded, IRQF_ONESHOT,
    526					"qt1050", ts);
    527	if (err) {
    528		dev_err(&client->dev, "Failed to request irq: %d\n", err);
    529		return err;
    530	}
    531
    532	/* Clear #CHANGE line */
    533	err = regmap_read(ts->regmap, QT1050_DET_STATUS, &status);
    534	if (err) {
    535		dev_err(dev, "Failed to clear #CHANGE line level: %d\n", err);
    536		return err;
    537	}
    538
    539	/* Register the input device */
    540	err = input_register_device(ts->input);
    541	if (err) {
    542		dev_err(&client->dev, "Failed to register input device: %d\n",
    543			err);
    544		return err;
    545	}
    546
    547	return 0;
    548}
    549
    550static int __maybe_unused qt1050_suspend(struct device *dev)
    551{
    552	struct i2c_client *client = to_i2c_client(dev);
    553	struct qt1050_priv *ts = i2c_get_clientdata(client);
    554
    555	disable_irq(client->irq);
    556
    557	/*
    558	 * Set measurement interval to 1s (125 x 8ms) if wakeup is allowed
    559	 * else turn off. The 1s interval seems to be a good compromise between
    560	 * low power and response time.
    561	 */
    562	return regmap_write(ts->regmap, QT1050_LPMODE,
    563			    device_may_wakeup(dev) ? 125 : 0);
    564}
    565
    566static int __maybe_unused qt1050_resume(struct device *dev)
    567{
    568	struct i2c_client *client = to_i2c_client(dev);
    569	struct qt1050_priv *ts = i2c_get_clientdata(client);
    570
    571	enable_irq(client->irq);
    572
    573	/* Set measurement interval back to 16ms (2 x 8ms) */
    574	return regmap_write(ts->regmap, QT1050_LPMODE, 2);
    575}
    576
    577static SIMPLE_DEV_PM_OPS(qt1050_pm_ops, qt1050_suspend, qt1050_resume);
    578
    579static const struct of_device_id __maybe_unused qt1050_of_match[] = {
    580	{ .compatible = "microchip,qt1050", },
    581	{ },
    582};
    583MODULE_DEVICE_TABLE(of, qt1050_of_match);
    584
    585static struct i2c_driver qt1050_driver = {
    586	.driver	= {
    587		.name = "qt1050",
    588		.of_match_table = of_match_ptr(qt1050_of_match),
    589		.pm = &qt1050_pm_ops,
    590	},
    591	.probe_new = qt1050_probe,
    592};
    593
    594module_i2c_driver(qt1050_driver);
    595
    596MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de");
    597MODULE_DESCRIPTION("Driver for AT42QT1050 QTouch sensor");
    598MODULE_LICENSE("GPL v2");