Input: add bu21029 touch driver (3a658f23) · Commits · e / devices / android_kernel_fairphone_FP4

Documentation/devicetree/bindings/input/touchscreen/bu21029.txt

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			* Rohm BU21029 Touch Screen Controller

			Required properties:
			- compatible : must be "rohm,bu21029"
			- reg : i2c device address of the chip (0x40 or 0x41)
			- interrupt-parent : the phandle for the gpio controller
			- interrupts : (gpio) interrupt to which the chip is connected
			- rohm,x-plate-ohms : x-plate resistance in Ohm

			Optional properties:
			- reset-gpios : gpio pin to reset the chip (active low)
			- touchscreen-size-x : horizontal resolution of touchscreen (in pixels)
			- touchscreen-size-y : vertical resolution of touchscreen (in pixels)
			- touchscreen-max-pressure: maximum pressure value
			- vdd-supply : power supply for the controller

			Example:

			&i2c1 {
			/* ... */

			bu21029: bu21029@40 {
			compatible = "rohm,bu21029";
			reg = <0x40>;
			interrupt-parent = <&gpio1>;
			interrupts = <4 IRQ_TYPE_EDGE_FALLING>;
			reset-gpios = <&gpio6 16 GPIO_ACTIVE_LOW>;
			rohm,x-plate-ohms = <600>;
			touchscreen-size-x = <800>;
			touchscreen-size-y = <480>;
			touchscreen-max-pressure = <4095>;
			};

			/* ... */
			};

drivers/input/touchscreen/Kconfig

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	@@ -151,6 +151,18 @@ config TOUCHSCREEN_BU21013
	To compile this driver as a module, choose M here: the		To compile this driver as a module, choose M here: the
	module will be called bu21013_ts.		module will be called bu21013_ts.

			config TOUCHSCREEN_BU21029
			tristate "Rohm BU21029 based touch panel controllers"
			depends on I2C
			help
			Say Y here if you have a Rohm BU21029 touchscreen controller
			connected to your system.

			If unsure, say N.

			To compile this driver as a module, choose M here: the
			module will be called bu21029_ts.

	config TOUCHSCREEN_CHIPONE_ICN8318		config TOUCHSCREEN_CHIPONE_ICN8318
	tristate "chipone icn8318 touchscreen controller"		tristate "chipone icn8318 touchscreen controller"
	depends on GPIOLIB \|\| COMPILE_TEST		depends on GPIOLIB \|\| COMPILE_TEST

drivers/input/touchscreen/Makefile

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Original line number	Original line	Diff line number	Diff line
	@@ -18,6 +18,7 @@ obj-$(CONFIG_TOUCHSCREEN_AR1021_I2C) += ar1021_i2c.o
	obj-$(CONFIG_TOUCHSCREEN_ATMEL_MXT) += atmel_mxt_ts.o		obj-$(CONFIG_TOUCHSCREEN_ATMEL_MXT) += atmel_mxt_ts.o
	obj-$(CONFIG_TOUCHSCREEN_AUO_PIXCIR) += auo-pixcir-ts.o		obj-$(CONFIG_TOUCHSCREEN_AUO_PIXCIR) += auo-pixcir-ts.o
	obj-$(CONFIG_TOUCHSCREEN_BU21013) += bu21013_ts.o		obj-$(CONFIG_TOUCHSCREEN_BU21013) += bu21013_ts.o
			obj-$(CONFIG_TOUCHSCREEN_BU21029) += bu21029_ts.o
	obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8318) += chipone_icn8318.o		obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8318) += chipone_icn8318.o
	obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8505) += chipone_icn8505.o		obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8505) += chipone_icn8505.o
	obj-$(CONFIG_TOUCHSCREEN_CY8CTMG110) += cy8ctmg110_ts.o		obj-$(CONFIG_TOUCHSCREEN_CY8CTMG110) += cy8ctmg110_ts.o

drivers/input/touchscreen/bu21029_ts.c

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			// SPDX-License-Identifier: GPL-2.0
			/*
			* Rohm BU21029 touchscreen controller driver
			*
			* Copyright (C) 2015-2018 Bosch Sicherheitssysteme GmbH
			*
			* This program is free software; you can redistribute it and/or modify
			* it under the terms of the GNU General Public License version 2 as
			* published by the Free Software Foundation.
			*/

			#include <linux/delay.h>
			#include <linux/gpio/consumer.h>
			#include <linux/i2c.h>
			#include <linux/input.h>
			#include <linux/input/touchscreen.h>
			#include <linux/interrupt.h>
			#include <linux/irq.h>
			#include <linux/module.h>
			#include <linux/regulator/consumer.h>
			#include <linux/timer.h>

			/*
			* HW_ID1 Register (PAGE=0, ADDR=0x0E, Reset value=0x02, Read only)
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| D7 \| D6 \| D5 \| D4 \| D3 \| D2 \| D1 \| D0 \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| HW_IDH \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* HW_ID2 Register (PAGE=0, ADDR=0x0F, Reset value=0x29, Read only)
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| D7 \| D6 \| D5 \| D4 \| D3 \| D2 \| D1 \| D0 \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| HW_IDL \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* HW_IDH: high 8bits of IC's ID
			* HW_IDL: low 8bits of IC's ID
			*/
			#define BU21029_HWID_REG (0x0E << 3)
			#define SUPPORTED_HWID 0x0229

			/*
			* CFR0 Register (PAGE=0, ADDR=0x00, Reset value=0x20)
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| D7 \| D6 \| D5 \| D4 \| D3 \| D2 \| D1 \| D0 \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| 0 \| 0 \| CALIB \| INTRM \| 0 \| 0 \| 0 \| 0 \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* CALIB: 0 = not to use calibration result (*)
			* 1 = use calibration result
			* INTRM: 0 = INT output depend on "pen down" (*)
			* 1 = INT output always "0"
			*/
			#define BU21029_CFR0_REG (0x00 << 3)
			#define CFR0_VALUE 0x00

			/*
			* CFR1 Register (PAGE=0, ADDR=0x01, Reset value=0xA6)
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| D7 \| D6 \| D5 \| D4 \| D3 \| D2 \| D1 \| D0 \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| MAV \| AVE[2:0] \| 0 \| SMPL[2:0] \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* MAV: 0 = median average filter off
			* 1 = median average filter on (*)
			* AVE: AVE+1 = number of average samples for MAV,
			* if AVE>SMPL, then AVE=SMPL (=3)
			* SMPL: SMPL+1 = number of conversion samples for MAV (=7)
			*/
			#define BU21029_CFR1_REG (0x01 << 3)
			#define CFR1_VALUE 0xA6

			/*
			* CFR2 Register (PAGE=0, ADDR=0x02, Reset value=0x04)
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| D7 \| D6 \| D5 \| D4 \| D3 \| D2 \| D1 \| D0 \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| INTVL_TIME[3:0] \| TIME_ST_ADC[3:0] \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* INTVL_TIME: waiting time between completion of conversion
			* and start of next conversion, only usable in
			* autoscan mode (=20.480ms)
			* TIME_ST_ADC: waiting time between application of voltage
			* to panel and start of A/D conversion (=100us)
			*/
			#define BU21029_CFR2_REG (0x02 << 3)
			#define CFR2_VALUE 0xC9

			/*
			* CFR3 Register (PAGE=0, ADDR=0x0B, Reset value=0x72)
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| D7 \| D6 \| D5 \| D4 \| D3 \| D2 \| D1 \| D0 \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| RM8 \| STRETCH\| PU90K \| DUAL \| PIDAC_OFS[3:0] \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* RM8: 0 = coordinate resolution is 12bit (*)
			* 1 = coordinate resolution is 8bit
			* STRETCH: 0 = SCL_STRETCH function off
			* 1 = SCL_STRETCH function on (*)
			* PU90K: 0 = internal pull-up resistance for touch detection is ~50kohms (*)
			* 1 = internal pull-up resistance for touch detection is ~90kohms
			* DUAL: 0 = dual touch detection off (*)
			* 1 = dual touch detection on
			* PIDAC_OFS: dual touch detection circuit adjustment, it is not necessary
			* to change this from initial value
			*/
			#define BU21029_CFR3_REG (0x0B << 3)
			#define CFR3_VALUE 0x42

			/*
			* LDO Register (PAGE=0, ADDR=0x0C, Reset value=0x00)
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| D7 \| D6 \| D5 \| D4 \| D3 \| D2 \| D1 \| D0 \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| 0 \| PVDD[2:0] \| 0 \| AVDD[2:0] \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* PVDD: output voltage of panel output regulator (=2.000V)
			* AVDD: output voltage of analog circuit regulator (=2.000V)
			*/
			#define BU21029_LDO_REG (0x0C << 3)
			#define LDO_VALUE 0x77

			/*
			* Serial Interface Command Byte 1 (CID=1)
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| D7 \| D6 \| D5 \| D4 \| D3 \| D2 \| D1 \| D0 \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* \| 1 \| CF \| CMSK \| PDM \| STP \|
			* +--------+--------+--------+--------+--------+--------+--------+--------+
			* CF: conversion function, see table 3 in datasheet p6 (=0000, automatic scan)
			* CMSK: 0 = executes convert function (*)
			* 1 = reads the convert result
			* PDM: 0 = power down after convert function stops (*)
			* 1 = keep power on after convert function stops
			* STP: 1 = abort current conversion and power down, set to "0" automatically
			*/
			#define BU21029_AUTOSCAN 0x80

			/*
			* The timeout value needs to be larger than INTVL_TIME + tConv4 (sample and
			* conversion time), where tConv4 is calculated by formula:
			* tPON + tDLY1 + (tTIME_ST_ADC + (tADC * tSMPL) * 2 + tDLY2) * 3
			* see figure 8 in datasheet p15 for details of each field.
			*/
			#define PEN_UP_TIMEOUT_MS 50

			#define STOP_DELAY_MIN_US 50
			#define STOP_DELAY_MAX_US 1000
			#define START_DELAY_MS 2
			#define BUF_LEN 8
			#define SCALE_12BIT (1 << 12)
			#define MAX_12BIT ((1 << 12) - 1)
			#define DRIVER_NAME "bu21029"

			struct bu21029_ts_data {
			struct i2c_client *client;
			struct input_dev *in_dev;
			struct timer_list timer;
			struct regulator *vdd;
			struct gpio_desc *reset_gpios;
			u32 x_plate_ohms;
			struct touchscreen_properties prop;
			};

			static void bu21029_touch_report(struct bu21029_ts_data bu21029, const u8 buf)
			{
			u16 x, y, z1, z2;
			u32 rz;
			s32 max_pressure = input_abs_get_max(bu21029->in_dev, ABS_PRESSURE);

			/*
			* compose upper 8 and lower 4 bits into a 12bit value:
			* +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
			* \| ByteH \| ByteL \|
			* +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
			* \|b07\|b06\|b05\|b04\|b03\|b02\|b01\|b00\|b07\|b06\|b05\|b04\|b03\|b02\|b01\|b00\|
			* +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
			* \|v11\|v10\|v09\|v08\|v07\|v06\|v05\|v04\|v03\|v02\|v01\|v00\| 0 \| 0 \| 0 \| 0 \|
			* +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
			*/
			x = (buf[0] << 4) \| (buf[1] >> 4);
			y = (buf[2] << 4) \| (buf[3] >> 4);
			z1 = (buf[4] << 4) \| (buf[5] >> 4);
			z2 = (buf[6] << 4) \| (buf[7] >> 4);

			if (z1 && z2) {
			/*
			* calculate Rz (pressure resistance value) by equation:
			* Rz = Rx * (x/Q) * ((z2/z1) - 1), where
			* Rx is x-plate resistance,
			* Q is the touch screen resolution (8bit = 256, 12bit = 4096)
			* x, z1, z2 are the measured positions.
			*/
			rz = z2 - z1;
			rz *= x;
			rz *= bu21029->x_plate_ohms;
			rz /= z1;
			rz = DIV_ROUND_CLOSEST(rz, SCALE_12BIT);
			if (rz <= max_pressure) {
			touchscreen_report_pos(bu21029->in_dev, &bu21029->prop,
			x, y, false);
			input_report_abs(bu21029->in_dev, ABS_PRESSURE,
			max_pressure - rz);
			input_report_key(bu21029->in_dev, BTN_TOUCH, 1);
			input_sync(bu21029->in_dev);
			}
			}
			}

			static void bu21029_touch_release(struct timer_list *t)
			{
			struct bu21029_ts_data *bu21029 = from_timer(bu21029, t, timer);

			input_report_abs(bu21029->in_dev, ABS_PRESSURE, 0);
			input_report_key(bu21029->in_dev, BTN_TOUCH, 0);
			input_sync(bu21029->in_dev);
			}

			static irqreturn_t bu21029_touch_soft_irq(int irq, void *data)
			{
			struct bu21029_ts_data *bu21029 = data;
			u8 buf[BUF_LEN];
			int error;

			/*
			* Read touch data and deassert interrupt (will assert again after
			* INTVL_TIME + tConv4 for continuous touch)
			*/
			error = i2c_smbus_read_i2c_block_data(bu21029->client, BU21029_AUTOSCAN,
			sizeof(buf), buf);
			if (error < 0)
			goto out;

			bu21029_touch_report(bu21029, buf);

			/* reset timer for pen up detection */
			mod_timer(&bu21029->timer,
			jiffies + msecs_to_jiffies(PEN_UP_TIMEOUT_MS));

			out:
			return IRQ_HANDLED;
			}

			static void bu21029_put_chip_in_reset(struct bu21029_ts_data *bu21029)
			{
			if (bu21029->reset_gpios) {
			gpiod_set_value_cansleep(bu21029->reset_gpios, 1);
			usleep_range(STOP_DELAY_MIN_US, STOP_DELAY_MAX_US);
			}
			}

			static int bu21029_start_chip(struct input_dev *dev)
			{
			struct bu21029_ts_data *bu21029 = input_get_drvdata(dev);
			struct i2c_client *i2c = bu21029->client;
			struct {
			u8 reg;
			u8 value;
			} init_table[] = {
			{BU21029_CFR0_REG, CFR0_VALUE},
			{BU21029_CFR1_REG, CFR1_VALUE},
			{BU21029_CFR2_REG, CFR2_VALUE},
			{BU21029_CFR3_REG, CFR3_VALUE},
			{BU21029_LDO_REG, LDO_VALUE}
			};
			int error, i;
			__be16 hwid;

			error = regulator_enable(bu21029->vdd);
			if (error) {
			dev_err(&i2c->dev, "failed to power up chip: %d", error);
			return error;
			}

			/* take chip out of reset */
			if (bu21029->reset_gpios) {
			gpiod_set_value_cansleep(bu21029->reset_gpios, 0);
			msleep(START_DELAY_MS);
			}

			error = i2c_smbus_read_i2c_block_data(i2c, BU21029_HWID_REG,
			sizeof(hwid), (u8 *)&hwid);
			if (error < 0) {
			dev_err(&i2c->dev, "failed to read HW ID\n");
			goto err_out;
			}

			if (be16_to_cpu(hwid) != SUPPORTED_HWID) {
			dev_err(&i2c->dev,
			"unsupported HW ID 0x%x\n", be16_to_cpu(hwid));
			error = -ENODEV;
			goto err_out;
			}

			for (i = 0; i < ARRAY_SIZE(init_table); ++i) {
			error = i2c_smbus_write_byte_data(i2c,
			init_table[i].reg,
			init_table[i].value);
			if (error < 0) {
			dev_err(&i2c->dev,
			"failed to write %#02x to register %#02x: %d\n",
			init_table[i].value, init_table[i].reg,
			error);
			goto err_out;
			}
			}

			error = i2c_smbus_write_byte(i2c, BU21029_AUTOSCAN);
			if (error < 0) {
			dev_err(&i2c->dev, "failed to start autoscan\n");
			goto err_out;
			}

			enable_irq(bu21029->client->irq);
			return 0;

			err_out:
			bu21029_put_chip_in_reset(bu21029);
			regulator_disable(bu21029->vdd);
			return error;
			}

			static void bu21029_stop_chip(struct input_dev *dev)
			{
			struct bu21029_ts_data *bu21029 = input_get_drvdata(dev);

			disable_irq(bu21029->client->irq);
			del_timer_sync(&bu21029->timer);

			bu21029_put_chip_in_reset(bu21029);
			regulator_disable(bu21029->vdd);
			}

			static int bu21029_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
			{
			struct bu21029_ts_data *bu21029;
			struct input_dev *in_dev;
			int error;

			if (!i2c_check_functionality(client->adapter,
			I2C_FUNC_SMBUS_WRITE_BYTE \|
			I2C_FUNC_SMBUS_WRITE_BYTE_DATA \|
			I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
			dev_err(&client->dev,
			"i2c functionality support is not sufficient\n");
			return -EIO;
			}

			bu21029 = devm_kzalloc(&client->dev, sizeof(*bu21029), GFP_KERNEL);
			if (!bu21029)
			return -ENOMEM;

			error = device_property_read_u32(&client->dev, "rohm,x-plate-ohms",
			&bu21029->x_plate_ohms);
			if (error) {
			dev_err(&client->dev,
			"invalid 'x-plate-ohms' supplied: %d\n", error);
			return error;
			}

			bu21029->vdd = devm_regulator_get(&client->dev, "vdd");
			if (IS_ERR(bu21029->vdd)) {
			error = PTR_ERR(bu21029->vdd);
			if (error != -EPROBE_DEFER)
			dev_err(&client->dev,
			"failed to acquire 'vdd' supply: %d\n", error);
			return error;
			}

			bu21029->reset_gpios = devm_gpiod_get_optional(&client->dev,
			"reset", GPIOD_OUT_HIGH);
			if (IS_ERR(bu21029->reset_gpios)) {
			error = PTR_ERR(bu21029->reset_gpios);
			if (error != -EPROBE_DEFER)
			dev_err(&client->dev,
			"failed to acquire 'reset' gpio: %d\n", error);
			return error;
			}

			in_dev = devm_input_allocate_device(&client->dev);
			if (!in_dev) {
			dev_err(&client->dev, "unable to allocate input device\n");
			return -ENOMEM;
			}

			bu21029->client = client;
			bu21029->in_dev = in_dev;
			timer_setup(&bu21029->timer, bu21029_touch_release, 0);

			in_dev->name = DRIVER_NAME;
			in_dev->id.bustype = BUS_I2C;
			in_dev->open = bu21029_start_chip;
			in_dev->close = bu21029_stop_chip;

			input_set_capability(in_dev, EV_KEY, BTN_TOUCH);
			input_set_abs_params(in_dev, ABS_X, 0, MAX_12BIT, 0, 0);
			input_set_abs_params(in_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
			input_set_abs_params(in_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
			touchscreen_parse_properties(in_dev, false, &bu21029->prop);

			input_set_drvdata(in_dev, bu21029);

			irq_set_status_flags(client->irq, IRQ_NOAUTOEN);
			error = devm_request_threaded_irq(&client->dev, client->irq,
			NULL, bu21029_touch_soft_irq,
			IRQF_ONESHOT, DRIVER_NAME, bu21029);
			if (error) {
			dev_err(&client->dev,
			"unable to request touch irq: %d\n", error);
			return error;
			}

			error = input_register_device(in_dev);
			if (error) {
			dev_err(&client->dev,
			"unable to register input device: %d\n", error);
			return error;
			}

			i2c_set_clientdata(client, bu21029);

			return 0;
			}

			static int __maybe_unused bu21029_suspend(struct device *dev)
			{
			struct i2c_client *i2c = to_i2c_client(dev);
			struct bu21029_ts_data *bu21029 = i2c_get_clientdata(i2c);

			if (!device_may_wakeup(dev)) {
			mutex_lock(&bu21029->in_dev->mutex);
			if (bu21029->in_dev->users)
			bu21029_stop_chip(bu21029->in_dev);
			mutex_unlock(&bu21029->in_dev->mutex);
			}

			return 0;
			}

			static int __maybe_unused bu21029_resume(struct device *dev)
			{
			struct i2c_client *i2c = to_i2c_client(dev);
			struct bu21029_ts_data *bu21029 = i2c_get_clientdata(i2c);

			if (!device_may_wakeup(dev)) {
			mutex_lock(&bu21029->in_dev->mutex);
			if (bu21029->in_dev->users)
			bu21029_start_chip(bu21029->in_dev);
			mutex_unlock(&bu21029->in_dev->mutex);
			}

			return 0;
			}
			static SIMPLE_DEV_PM_OPS(bu21029_pm_ops, bu21029_suspend, bu21029_resume);

			static const struct i2c_device_id bu21029_ids[] = {
			{ DRIVER_NAME, 0 },
			{ /* sentinel */ }
			};
			MODULE_DEVICE_TABLE(i2c, bu21029_ids);

			#ifdef CONFIG_OF
			static const struct of_device_id bu21029_of_ids[] = {
			{ .compatible = "rohm,bu21029" },
			{ /* sentinel */ }
			};
			MODULE_DEVICE_TABLE(of, bu21029_of_ids);
			#endif

			static struct i2c_driver bu21029_driver = {
			.driver = {
			.name = DRIVER_NAME,
			.of_match_table = of_match_ptr(bu21029_of_ids),
			.pm = &bu21029_pm_ops,
			},
			.id_table = bu21029_ids,
			.probe = bu21029_probe,
			};
			module_i2c_driver(bu21029_driver);

			MODULE_AUTHOR("Zhu Yi <yi.zhu5@cn.bosch.com>");
			MODULE_DESCRIPTION("Rohm BU21029 touchscreen controller driver");
			MODULE_LICENSE("GPL v2");