Hi Mark, On Wed, Mar 21, 2018 at 06:04:34PM +0100, Mark Jonas wrote: > From: Zhu Yi <yi.zhu5@xxxxxxxxxxxx> > > Add the ROHM BU21029 resistive touch panel controller > support with i2c interface. > > Signed-off-by: Zhu Yi <yi.zhu5@xxxxxxxxxxxx> > Signed-off-by: Mark Jonas <mark.jonas@xxxxxxxxxxxx> > Reviewed-by: Heiko Schocher <hs@xxxxxxx> > --- > .../bindings/input/touchscreen/bu21029.txt | 30 ++ > drivers/input/touchscreen/Kconfig | 12 + > drivers/input/touchscreen/Makefile | 1 + > drivers/input/touchscreen/bu21029_ts.c | 456 +++++++++++++++++++++ > 4 files changed, 499 insertions(+) > create mode 100644 Documentation/devicetree/bindings/input/touchscreen/bu21029.txt > create mode 100644 drivers/input/touchscreen/bu21029_ts.c > > diff --git a/Documentation/devicetree/bindings/input/touchscreen/bu21029.txt b/Documentation/devicetree/bindings/input/touchscreen/bu21029.txt > new file mode 100644 > index 0000000..7b61602 > --- /dev/null > +++ b/Documentation/devicetree/bindings/input/touchscreen/bu21029.txt > @@ -0,0 +1,30 @@ > +* Rohm BU21029 Touch Screen Controller > + > +Required properties: > + - compatible : must be "rohm,bu21029" > + - reg : i2c device address of the chip > + - 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 > + - rohm,x-plate-ohms : x-plate resistance in ohms > + > +Optional properties: > + - 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-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..d5cbf11 > --- /dev/null > +++ b/drivers/input/touchscreen/bu21029_ts.c > @@ -0,0 +1,456 @@ Please add SPDX tag for the driver. > +/* > + * Rohm BU21029 touchscreen controller driver > + * > + * Copyright (C) 2015 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.h> > +#include <linux/i2c.h> > +#include <linux/input.h> > +#include <linux/interrupt.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_gpio.h> Please use GPIOD API (and include linux/gpio/consumer.h instead of of_gpio.h). > +#include <linux/timer.h> > + > +/* HW_ID1 Register (PAGE=0, ADDR=0x0E, Reset value=0x02, Read only) Multi-line comments start with empty comment line: /* * Multi * line. */ > + * +--------+--------+--------+--------+--------+--------+--------+--------+ > + * | 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; > + u32 reset_gpios; > + u32 reset_gpios_assert; > + u32 x_plate_ohms; > + u32 max_pressure; > +}; > + > +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; > + > + /* 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 <= bu21029->max_pressure) { > + input_report_abs(bu21029->in_dev, ABS_X, x); > + input_report_abs(bu21029->in_dev, ABS_Y, y); > + input_report_abs(bu21029->in_dev, ABS_PRESSURE, rz); What is the values of pressure reported when finger is touching the surface? IOW is 'rz' pressure or resistance? > + 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_reset_chip(struct bu21029_ts_data *bu21029) > +{ > + gpio_set_value(bu21029->reset_gpios, > + bu21029->reset_gpios_assert); > + udelay(STOP_DELAY_US); > + gpio_set_value(bu21029->reset_gpios, > + !bu21029->reset_gpios_assert); > + mdelay(START_DELAY_MS); > +} > + > +static int bu21029_init_chip(struct bu21029_ts_data *bu21029) > +{ > + 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; > + > + bu21029_reset_chip(bu21029); > + > + 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"); > + return error; > + } > + > + if (cpu_to_be16(hwid) != SUPPORTED_HWID) { > + dev_err(&i2c->dev, "unsupported HW ID 0x%x\n", hwid); > + return -ENODEV; > + } > + > + 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); > + return error; > + } > + } > + > + error = i2c_smbus_write_byte(i2c, BU21029_AUTOSCAN); > + if (error < 0) { > + dev_err(&i2c->dev, "failed to start autoscan\n"); > + return error; > + } > + > + return 0; > +} > + > +static int bu21029_parse_dt(struct bu21029_ts_data *bu21029) > +{ > + struct device *dev = &bu21029->client->dev; > + struct device_node *np = dev->of_node; > + enum of_gpio_flags flags; > + u32 val32; > + int gpio; > + > + if (!np) { > + dev_err(dev, "no device tree data\n"); > + return -EINVAL; > + } > + > + gpio = of_get_named_gpio_flags(np, "reset-gpios", 0, &flags); > + if (!gpio_is_valid(gpio)) { > + dev_err(dev, "invalid 'reset-gpios' supplied\n"); > + return -EINVAL; > + } > + bu21029->reset_gpios = gpio; > + bu21029->reset_gpios_assert = (flags & OF_GPIO_ACTIVE_LOW) ? 0 : 1; > + > + 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; > + > + if (of_property_read_u32(np, "touchscreen-max-pressure", &val32)) > + bu21029->max_pressure = MAX_12BIT; > + else > + bu21029->max_pressure = val32; Please use infrastructure form include/linux/input/touchscreen.h so that you handle different sizes and orientations. > + > + 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); > + > + error = bu21029_parse_dt(bu21029); > + if (error) > + return error; > + > + error = devm_gpio_request_one(&client->dev, > + bu21029->reset_gpios, > + GPIOF_OUT_INIT_HIGH, > + DRIVER_NAME); > + if (error) { > + dev_err(&client->dev, "unable to request reset-gpios\n"); > + return error; > + } > + > + error = bu21029_init_chip(bu21029); > + if (error) { > + dev_err(&client->dev, "unable to config bu21029\n"); > + return error; > + } > + > + in_dev->name = DRIVER_NAME; > + in_dev->id.bustype = BUS_I2C; > + in_dev->dev.parent = &client->dev; Not needed with devm_input_allocate_device(). > + > + __set_bit(EV_SYN, in_dev->evbit); > + __set_bit(EV_KEY, in_dev->evbit); > + __set_bit(EV_ABS, in_dev->evbit); > + __set_bit(ABS_X, in_dev->absbit); > + __set_bit(ABS_Y, in_dev->absbit); > + __set_bit(ABS_PRESSURE, in_dev->absbit); > + __set_bit(BTN_TOUCH, in_dev->keybit); > + > + 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, bu21029->max_pressure, 0, 0); > + input_set_drvdata(in_dev, bu21029); > + > + 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); > + > + 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; > + } > + > + return 0; > +} > + > +static int bu21029_remove(struct i2c_client *client) > +{ > + struct bu21029_ts_data *bu21029 = i2c_get_clientdata(client); > + > + del_timer_sync(&bu21029->timer); If interrupt comes here kernel will be unhappy. You need to either work canceling timer into devm unwid stream (devm_add_action_or_reset()) or somehow make sure that you shut off interrupts before canceling the timer. > + > + return 0; > +} > + > +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, > + .owner = THIS_MODULE, Not needed. > + }, > + .id_table = bu21029_ids, > + .probe = bu21029_probe, > + .remove = bu21029_remove, > +}; > +module_i2c_driver(bu21029_driver); > + > +MODULE_AUTHOR("Zhu Yi <yi.zhu5@xxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Rohm BU21029 touchscreen controller driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.7.4 > Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html