[v3] Input: add bu21029 touch driver

Message ID	1526048528-3613-1-git-send-email-mark.jonas@de.bosch.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-input-owner@kernel.org> From: Mark Jonas <mark.jonas@de.bosch.com> To: Dmitry Torokhov <dmitry.torokhov@gmail.com>, Rob Herring <robh+dt@kernel.org>, Mark Rutland <mark.rutland@arm.com> CC: <linux-input@vger.kernel.org>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <hs@denx.de>, Zhu Yi <yi.zhu5@cn.bosch.com>, Mark Jonas <mark.jonas@de.bosch.com> Subject: [PATCH v3] Input: add bu21029 touch driver Date: Fri, 11 May 2018 16:22:08 +0200 Message-ID: <1526048528-3613-1-git-send-email-mark.jonas@de.bosch.com> In-Reply-To: <1521651874-15379-1-git-send-email-mark.jonas@de.bosch.com> References: <1521651874-15379-1-git-send-email-mark.jonas@de.bosch.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-input-owner@vger.kernel.org Precedence: bulk

diff --git a/Documentation/devicetree/bindings/input/touchscreen/bu21029.txt b/Documentation/devicetree/bindings/input/touchscreen/bu21029.txt new file mode 100644 index 0000000..030a888 --- /dev/null +++ b/Documentation/devicetree/bindings/input/touchscreen/bu21029.txt @@ -0,0 +1,34 @@ +* 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 + - reset-gpios : gpio pin to reset the chip (active low) + - rohm,x-plate-ohms : x-plate resistance in Ohm + +Optional properties: + - touchscreen-size-x : horizontal resolution of touchscreen (in pixels) + - touchscreen-size-y : vertical resolution of touchscreen (in pixels) + - touchscreen-max-pressure: maximum pressure value + +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>; + }; + + /* ... */ + }; diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig index 4f15496..e09fe8f 100644 --- a/drivers/input/touchscreen/Kconfig +++ b/drivers/input/touchscreen/Kconfig @@ -151,6 +151,18 @@ config TOUCHSCREEN_BU21013 To compile this driver as a module, choose M here: the 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 tristate "chipone icn8318 touchscreen controller" depends on GPIOLIB || COMPILE_TEST diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile index dddae79..f50624c 100644 --- a/drivers/input/touchscreen/Makefile +++ b/drivers/input/touchscreen/Makefile @@ -18,6 +18,7 @@ obj-$(CONFIG_TOUCHSCREEN_AR1021_I2C) += ar1021_i2c.o obj-$(CONFIG_TOUCHSCREEN_ATMEL_MXT) += atmel_mxt_ts.o obj-$(CONFIG_TOUCHSCREEN_AUO_PIXCIR) += auo-pixcir-ts.o obj-$(CONFIG_TOUCHSCREEN_BU21013) += bu21013_ts.o +obj-$(CONFIG_TOUCHSCREEN_BU21029) += bu21029_ts.o obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8318) += chipone_icn8318.o obj-$(CONFIG_TOUCHSCREEN_CY8CTMG110) += cy8ctmg110_ts.o obj-$(CONFIG_TOUCHSCREEN_CYTTSP_CORE) += cyttsp_core.o diff --git a/drivers/input/touchscreen/bu21029_ts.c b/drivers/input/touchscreen/bu21029_ts.c new file mode 100644 index 0000000..8d0cbe51 --- /dev/null +++ b/drivers/input/touchscreen/bu21029_ts.c @@ -0,0 +1,485 @@ +// 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/module.h> +#include <linux/of.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 msecs_to_jiffies(50) + +#define STOP_DELAY_US 50L +#define START_DELAY_MS 2L +#define BUF_LEN 8L +#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 gpio_desc *reset_gpios; + u32 x_plate_ohms; + struct touchscreen_properties prop; +}; + +static int bu21029_touch_report(struct bu21029_ts_data *bu21029) +{ + struct i2c_client *i2c = bu21029->client; + u8 buf[BUF_LEN]; + u16 x, y, z1, z2; + u32 rz; + s32 max_pressure = bu21029->in_dev->absinfo[ABS_PRESSURE].maximum; + + /* read touch data and deassert INT (by restarting the autoscan mode) */ + int error = i2c_smbus_read_i2c_block_data(i2c, + BU21029_AUTOSCAN, + BUF_LEN, + buf); + if (error < 0) + return error; + + /* + * 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 == 0 || z2 == 0) + return 0; + + /* + * 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); + } + + return 0; +} + +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; + struct i2c_client *i2c = bu21029->client; + + /* + * report touch and deassert interrupt (will assert again after + * INTVL_TIME + tConv4 for continuous touch) + */ + int error = bu21029_touch_report(bu21029); + + if (error) { + dev_err(&i2c->dev, "failed to report (error: %d)\n", error); + return IRQ_NONE; + } + + /* reset timer for pen up detection */ + mod_timer(&bu21029->timer, jiffies + PEN_UP_TIMEOUT); + + return IRQ_HANDLED; +} + +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); + + /* put chip into reset */ + gpiod_set_value_cansleep(bu21029->reset_gpios, 1); + udelay(STOP_DELAY_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; + u16 hwid; + + /* take chip out of reset */ + gpiod_set_value_cansleep(bu21029->reset_gpios, 0); + mdelay(START_DELAY_MS); + + error = i2c_smbus_read_i2c_block_data(i2c, + BU21029_HWID_REG, + 2, + (u8 *)&hwid); + if (error < 0) { + dev_err(&i2c->dev, "failed to read HW ID\n"); + goto out; + } + + if (cpu_to_be16(hwid) != SUPPORTED_HWID) { + dev_err(&i2c->dev, "unsupported HW ID 0x%x\n", hwid); + error = -ENODEV; + goto 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 0x%x to register 0x%x\n", + init_table[i].value, + init_table[i].reg); + goto out; + } + } + + error = i2c_smbus_write_byte(i2c, BU21029_AUTOSCAN); + if (error < 0) { + dev_err(&i2c->dev, "failed to start autoscan\n"); + goto out; + } + + enable_irq(bu21029->client->irq); + return 0; + +out: + bu21029_stop_chip(dev); + return error; +} + +static int bu21029_parse_dt(struct bu21029_ts_data *bu21029) +{ + struct device *dev = &bu21029->client->dev; + struct device_node *np = dev->of_node; + u32 val32; + int error; + + if (!np) { + dev_err(dev, "no device tree data\n"); + return -EINVAL; + } + + bu21029->reset_gpios = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); + if (IS_ERR(bu21029->reset_gpios)) { + error = PTR_ERR(bu21029->reset_gpios); + if (error != -EPROBE_DEFER) + dev_err(dev, "invalid 'reset-gpios':%d\n", error); + return error; + } + + if (of_property_read_u32(np, "rohm,x-plate-ohms", &val32)) { + dev_err(dev, "invalid 'x-plate-ohms' supplied\n"); + return -EINVAL; + } + bu21029->x_plate_ohms = val32; + + touchscreen_parse_properties(bu21029->in_dev, false, &bu21029->prop); + + return 0; +} + +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; + + 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); + + error = bu21029_parse_dt(bu21029); + if (error) + return error; + + input_set_drvdata(in_dev, bu21029); + + 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\n"); + return error; + } + + bu21029_stop_chip(in_dev); + + error = input_register_device(in_dev); + if (error) { + dev_err(&client->dev, "unable to register input device\n"); + return error; + } + + i2c_set_clientdata(client, bu21029); + + return 0; +} + +static int bu21029_remove(struct i2c_client *client) +{ + struct bu21029_ts_data *bu21029 = i2c_get_clientdata(client); + + bu21029_stop_chip(bu21029->in_dev); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int bu21029_suspend(struct device *dev) +{ + struct i2c_client *i2c = to_i2c_client(dev); + struct bu21029_ts_data *bu21029 = i2c_get_clientdata(i2c); + + 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 bu21029_resume(struct device *dev) +{ + struct i2c_client *i2c = to_i2c_client(dev); + struct bu21029_ts_data *bu21029 = i2c_get_clientdata(i2c); + + 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; +} +#endif +static SIMPLE_DEV_PM_OPS(bu21029_pm_ops, bu21029_suspend, bu21029_resume); + +static const struct i2c_device_id bu21029_ids[] = { + {DRIVER_NAME, 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, bu21029_ids); + +static struct i2c_driver bu21029_driver = { + .driver = { + .name = DRIVER_NAME, + .pm = &bu21029_pm_ops, + }, + .id_table = bu21029_ids, + .probe = bu21029_probe, + .remove = bu21029_remove, +}; +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");

[v3] Input: add bu21029 touch driver

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