| // SPDX-License-Identifier: GPL-2.0-only | 
 | /* | 
 |  * Driver for Cypress CY8CTMA140 (TMA140) touchscreen | 
 |  * (C) 2020 Linus Walleij <linus.walleij@linaro.org> | 
 |  * (C) 2007 Cypress | 
 |  * (C) 2007 Google, Inc. | 
 |  * | 
 |  * Inspired by the tma140_skomer.c driver in the Samsung GT-S7710 code | 
 |  * drop. The GT-S7710 is codenamed "Skomer", the code also indicates | 
 |  * that the same touchscreen was used in a product called "Lucas". | 
 |  * | 
 |  * The code drop for GT-S7710 also contains a firmware downloader and | 
 |  * 15 (!) versions of the firmware drop from Cypress. But here we assume | 
 |  * the firmware got downloaded to the touchscreen flash successfully and | 
 |  * just use it to read the fingers. The shipped vendor driver does the | 
 |  * same. | 
 |  */ | 
 |  | 
 | #include <linux/unaligned.h> | 
 | #include <linux/module.h> | 
 | #include <linux/kernel.h> | 
 | #include <linux/input.h> | 
 | #include <linux/input/touchscreen.h> | 
 | #include <linux/input/mt.h> | 
 | #include <linux/slab.h> | 
 | #include <linux/interrupt.h> | 
 | #include <linux/io.h> | 
 | #include <linux/i2c.h> | 
 | #include <linux/regulator/consumer.h> | 
 | #include <linux/delay.h> | 
 |  | 
 | #define CY8CTMA140_NAME			"cy8ctma140" | 
 |  | 
 | #define CY8CTMA140_MAX_FINGERS		4 | 
 |  | 
 | #define CY8CTMA140_GET_FINGERS		0x00 | 
 | #define CY8CTMA140_GET_FW_INFO		0x19 | 
 |  | 
 | /* This message also fits some bytes for touchkeys, if used */ | 
 | #define CY8CTMA140_PACKET_SIZE		31 | 
 |  | 
 | #define CY8CTMA140_INVALID_BUFFER_BIT	5 | 
 |  | 
 | struct cy8ctma140 { | 
 | 	struct input_dev *input; | 
 | 	struct touchscreen_properties props; | 
 | 	struct device *dev; | 
 | 	struct i2c_client *client; | 
 | 	struct regulator_bulk_data regulators[2]; | 
 | 	u8 prev_fingers; | 
 | 	u8 prev_f1id; | 
 | 	u8 prev_f2id; | 
 | }; | 
 |  | 
 | static void cy8ctma140_report(struct cy8ctma140 *ts, u8 *data, int n_fingers) | 
 | { | 
 | 	static const u8 contact_offsets[] = { 0x03, 0x09, 0x10, 0x16 }; | 
 | 	u8 *buf; | 
 | 	u16 x, y; | 
 | 	u8 w; | 
 | 	u8 id; | 
 | 	int slot; | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < n_fingers; i++) { | 
 | 		buf = &data[contact_offsets[i]]; | 
 |  | 
 | 		/* | 
 | 		 * Odd contacts have contact ID in the lower nibble of | 
 | 		 * the preceding byte, whereas even contacts have it in | 
 | 		 * the upper nibble of the following byte. | 
 | 		 */ | 
 | 		id = i % 2 ? buf[-1] & 0x0f : buf[5] >> 4; | 
 | 		slot = input_mt_get_slot_by_key(ts->input, id); | 
 | 		if (slot < 0) | 
 | 			continue; | 
 |  | 
 | 		x = get_unaligned_be16(buf); | 
 | 		y = get_unaligned_be16(buf + 2); | 
 | 		w = buf[4]; | 
 |  | 
 | 		dev_dbg(ts->dev, "finger %d: ID %02x (%d, %d) w: %d\n", | 
 | 			slot, id, x, y, w); | 
 |  | 
 | 		input_mt_slot(ts->input, slot); | 
 | 		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true); | 
 | 		touchscreen_report_pos(ts->input, &ts->props, x, y, true); | 
 | 		input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR, w); | 
 | 	} | 
 |  | 
 | 	input_mt_sync_frame(ts->input); | 
 | 	input_sync(ts->input); | 
 | } | 
 |  | 
 | static irqreturn_t cy8ctma140_irq_thread(int irq, void *d) | 
 | { | 
 | 	struct cy8ctma140 *ts = d; | 
 | 	u8 cmdbuf[] = { CY8CTMA140_GET_FINGERS }; | 
 | 	u8 buf[CY8CTMA140_PACKET_SIZE]; | 
 | 	struct i2c_msg msg[] = { | 
 | 		{ | 
 | 			.addr = ts->client->addr, | 
 | 			.flags = 0, | 
 | 			.len = sizeof(cmdbuf), | 
 | 			.buf = cmdbuf, | 
 | 		}, { | 
 | 			.addr = ts->client->addr, | 
 | 			.flags = I2C_M_RD, | 
 | 			.len = sizeof(buf), | 
 | 			.buf = buf, | 
 | 		}, | 
 | 	}; | 
 | 	u8 n_fingers; | 
 | 	int ret; | 
 |  | 
 | 	ret = i2c_transfer(ts->client->adapter, msg, ARRAY_SIZE(msg)); | 
 | 	if (ret != ARRAY_SIZE(msg)) { | 
 | 		if (ret < 0) | 
 | 			dev_err(ts->dev, "error reading message: %d\n", ret); | 
 | 		else | 
 | 			dev_err(ts->dev, "wrong number of messages\n"); | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	if (buf[1] & BIT(CY8CTMA140_INVALID_BUFFER_BIT)) { | 
 | 		dev_dbg(ts->dev, "invalid event\n"); | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	n_fingers = buf[2] & 0x0f; | 
 | 	if (n_fingers > CY8CTMA140_MAX_FINGERS) { | 
 | 		dev_err(ts->dev, "unexpected number of fingers: %d\n", | 
 | 			n_fingers); | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	cy8ctma140_report(ts, buf, n_fingers); | 
 |  | 
 | out: | 
 | 	return IRQ_HANDLED; | 
 | } | 
 |  | 
 | static int cy8ctma140_init(struct cy8ctma140 *ts) | 
 | { | 
 | 	u8 addr[1]; | 
 | 	u8 buf[5]; | 
 | 	int ret; | 
 |  | 
 | 	addr[0] = CY8CTMA140_GET_FW_INFO; | 
 | 	ret = i2c_master_send(ts->client, addr, 1); | 
 | 	if (ret < 0) { | 
 | 		dev_err(ts->dev, "error sending FW info message\n"); | 
 | 		return ret; | 
 | 	} | 
 | 	ret = i2c_master_recv(ts->client, buf, 5); | 
 | 	if (ret < 0) { | 
 | 		dev_err(ts->dev, "error receiving FW info message\n"); | 
 | 		return ret; | 
 | 	} | 
 | 	if (ret != 5) { | 
 | 		dev_err(ts->dev, "got only %d bytes\n", ret); | 
 | 		return -EIO; | 
 | 	} | 
 |  | 
 | 	dev_dbg(ts->dev, "vendor %c%c, HW ID %.2d, FW ver %.4d\n", | 
 | 		buf[0], buf[1], buf[3], buf[4]); | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int cy8ctma140_power_up(struct cy8ctma140 *ts) | 
 | { | 
 | 	int error; | 
 |  | 
 | 	error = regulator_bulk_enable(ARRAY_SIZE(ts->regulators), | 
 | 				      ts->regulators); | 
 | 	if (error) { | 
 | 		dev_err(ts->dev, "failed to enable regulators\n"); | 
 | 		return error; | 
 | 	} | 
 |  | 
 | 	msleep(250); | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static void cy8ctma140_power_down(struct cy8ctma140 *ts) | 
 | { | 
 | 	regulator_bulk_disable(ARRAY_SIZE(ts->regulators), | 
 | 			       ts->regulators); | 
 | } | 
 |  | 
 | /* Called from the registered devm action */ | 
 | static void cy8ctma140_power_off_action(void *d) | 
 | { | 
 | 	struct cy8ctma140 *ts = d; | 
 |  | 
 | 	cy8ctma140_power_down(ts); | 
 | } | 
 |  | 
 | static int cy8ctma140_probe(struct i2c_client *client) | 
 | { | 
 | 	struct cy8ctma140 *ts; | 
 | 	struct input_dev *input; | 
 | 	struct device *dev = &client->dev; | 
 | 	int error; | 
 |  | 
 | 	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL); | 
 | 	if (!ts) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	input = devm_input_allocate_device(dev); | 
 | 	if (!input) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	ts->dev = dev; | 
 | 	ts->client = client; | 
 | 	ts->input = input; | 
 |  | 
 | 	input_set_capability(input, EV_ABS, ABS_MT_POSITION_X); | 
 | 	input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y); | 
 | 	/* One byte for width 0..255 so this is the limit */ | 
 | 	input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0); | 
 | 	/* | 
 | 	 * This sets up event max/min capabilities and fuzz. | 
 | 	 * Some DT properties are compulsory so we do not need | 
 | 	 * to provide defaults for X/Y max or pressure max. | 
 | 	 * | 
 | 	 * We just initialize a very simple MT touchscreen here, | 
 | 	 * some devices use the capability of this touchscreen to | 
 | 	 * provide touchkeys, and in that case this needs to be | 
 | 	 * extended to handle touchkey input. | 
 | 	 * | 
 | 	 * The firmware takes care of finger tracking and dropping | 
 | 	 * invalid ranges. | 
 | 	 */ | 
 | 	touchscreen_parse_properties(input, true, &ts->props); | 
 | 	input_abs_set_fuzz(input, ABS_MT_POSITION_X, 0); | 
 | 	input_abs_set_fuzz(input, ABS_MT_POSITION_Y, 0); | 
 |  | 
 | 	error = input_mt_init_slots(input, CY8CTMA140_MAX_FINGERS, | 
 | 				  INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED); | 
 | 	if (error) | 
 | 		return error; | 
 |  | 
 | 	input->name = CY8CTMA140_NAME; | 
 | 	input->id.bustype = BUS_I2C; | 
 | 	input_set_drvdata(input, ts); | 
 |  | 
 | 	/* | 
 | 	 * VCPIN is the analog voltage supply | 
 | 	 * VDD is the digital voltage supply | 
 | 	 * since the voltage range of VDD overlaps that of VCPIN, | 
 | 	 * many designs to just supply both with a single voltage | 
 | 	 * source of ~3.3 V. | 
 | 	 */ | 
 | 	ts->regulators[0].supply = "vcpin"; | 
 | 	ts->regulators[1].supply = "vdd"; | 
 | 	error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->regulators), | 
 | 				      ts->regulators); | 
 | 	if (error) | 
 | 		return dev_err_probe(dev, error, "Failed to get regulators\n"); | 
 |  | 
 | 	error = cy8ctma140_power_up(ts); | 
 | 	if (error) | 
 | 		return error; | 
 |  | 
 | 	error = devm_add_action_or_reset(dev, cy8ctma140_power_off_action, ts); | 
 | 	if (error) { | 
 | 		dev_err(dev, "failed to install power off handler\n"); | 
 | 		return error; | 
 | 	} | 
 |  | 
 | 	error = devm_request_threaded_irq(dev, client->irq, | 
 | 					  NULL, cy8ctma140_irq_thread, | 
 | 					  IRQF_ONESHOT, CY8CTMA140_NAME, ts); | 
 | 	if (error) { | 
 | 		dev_err(dev, "irq %d busy? error %d\n", client->irq, error); | 
 | 		return error; | 
 | 	} | 
 |  | 
 | 	error = cy8ctma140_init(ts); | 
 | 	if (error) | 
 | 		return error; | 
 |  | 
 | 	error = input_register_device(input); | 
 | 	if (error) | 
 | 		return error; | 
 |  | 
 | 	i2c_set_clientdata(client, ts); | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int cy8ctma140_suspend(struct device *dev) | 
 | { | 
 | 	struct i2c_client *client = to_i2c_client(dev); | 
 | 	struct cy8ctma140 *ts = i2c_get_clientdata(client); | 
 |  | 
 | 	if (!device_may_wakeup(&client->dev)) | 
 | 		cy8ctma140_power_down(ts); | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int cy8ctma140_resume(struct device *dev) | 
 | { | 
 | 	struct i2c_client *client = to_i2c_client(dev); | 
 | 	struct cy8ctma140 *ts = i2c_get_clientdata(client); | 
 | 	int error; | 
 |  | 
 | 	if (!device_may_wakeup(&client->dev)) { | 
 | 		error = cy8ctma140_power_up(ts); | 
 | 		if (error) | 
 | 			return error; | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static DEFINE_SIMPLE_DEV_PM_OPS(cy8ctma140_pm, | 
 | 				cy8ctma140_suspend, cy8ctma140_resume); | 
 |  | 
 | static const struct i2c_device_id cy8ctma140_idtable[] = { | 
 | 	{ CY8CTMA140_NAME }, | 
 | 	{ /* sentinel */ } | 
 | }; | 
 | MODULE_DEVICE_TABLE(i2c, cy8ctma140_idtable); | 
 |  | 
 | static const struct of_device_id cy8ctma140_of_match[] = { | 
 | 	{ .compatible = "cypress,cy8ctma140", }, | 
 | 	{ /* sentinel */ } | 
 | }; | 
 | MODULE_DEVICE_TABLE(of, cy8ctma140_of_match); | 
 |  | 
 | static struct i2c_driver cy8ctma140_driver = { | 
 | 	.driver		= { | 
 | 		.name	= CY8CTMA140_NAME, | 
 | 		.pm	= pm_sleep_ptr(&cy8ctma140_pm), | 
 | 		.of_match_table = cy8ctma140_of_match, | 
 | 	}, | 
 | 	.id_table	= cy8ctma140_idtable, | 
 | 	.probe		= cy8ctma140_probe, | 
 | }; | 
 | module_i2c_driver(cy8ctma140_driver); | 
 |  | 
 | MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); | 
 | MODULE_DESCRIPTION("CY8CTMA140 TouchScreen Driver"); | 
 | MODULE_LICENSE("GPL v2"); |