// 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 <asm/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, 0 },
{ /* 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");
