From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/input/touchscreen/ektf2127.c | 381 +++++++++++++++++++++++++++++++++++ 1 file changed, 381 insertions(+) create mode 100644 drivers/input/touchscreen/ektf2127.c (limited to 'drivers/input/touchscreen/ektf2127.c') diff --git a/drivers/input/touchscreen/ektf2127.c b/drivers/input/touchscreen/ektf2127.c new file mode 100644 index 000000000..572a37d4e --- /dev/null +++ b/drivers/input/touchscreen/ektf2127.c @@ -0,0 +1,381 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Driver for ELAN eKTF2127 i2c touchscreen controller + * + * For this driver the layout of the Chipone icn8318 i2c + * touchscreencontroller is used. + * + * Author: + * Michel Verlaan + * Siebren Vroegindeweij + * + * Original chipone_icn8318 driver: + * Hans de Goede + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Packet header defines (first byte of data send / received) */ +#define EKTF2127_NOISE 0x40 +#define EKTF2127_RESPONSE 0x52 +#define EKTF2127_REQUEST 0x53 +#define EKTF2127_HELLO 0x55 +#define EKTF2127_REPORT2 0x5a +#define EKTF2127_REPORT 0x5d +#define EKTF2127_CALIB_DONE 0x66 + +/* Register defines (second byte of data send / received) */ +#define EKTF2127_ENV_NOISY 0x41 +#define EKTF2127_HEIGHT 0x60 +#define EKTF2127_WIDTH 0x63 + +/* 2 bytes header + 5 * 3 bytes coordinates + 3 bytes pressure info + footer */ +#define EKTF2127_TOUCH_REPORT_SIZE 21 +#define EKTF2127_MAX_TOUCHES 5 + +struct ektf2127_ts { + struct i2c_client *client; + struct input_dev *input; + struct gpio_desc *power_gpios; + struct touchscreen_properties prop; + int status_shift; +}; + +struct ektf2127_i2c_chip_data { + int status_shift; +}; + +static void ektf2127_parse_coordinates(const u8 *buf, unsigned int touch_count, + struct input_mt_pos *touches) +{ + int index = 0; + int i; + + for (i = 0; i < touch_count; i++) { + index = 2 + i * 3; + + touches[i].x = (buf[index] & 0x0f); + touches[i].x <<= 8; + touches[i].x |= buf[index + 2]; + + touches[i].y = (buf[index] & 0xf0); + touches[i].y <<= 4; + touches[i].y |= buf[index + 1]; + } +} + +static void ektf2127_report_event(struct ektf2127_ts *ts, const u8 *buf) +{ + struct input_mt_pos touches[EKTF2127_MAX_TOUCHES]; + int slots[EKTF2127_MAX_TOUCHES]; + unsigned int touch_count, i; + + touch_count = buf[1] & 0x07; + if (touch_count > EKTF2127_MAX_TOUCHES) { + dev_err(&ts->client->dev, + "Too many touches %d > %d\n", + touch_count, EKTF2127_MAX_TOUCHES); + touch_count = EKTF2127_MAX_TOUCHES; + } + + ektf2127_parse_coordinates(buf, touch_count, touches); + input_mt_assign_slots(ts->input, slots, touches, + touch_count, 0); + + for (i = 0; i < touch_count; i++) { + input_mt_slot(ts->input, slots[i]); + input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true); + touchscreen_report_pos(ts->input, &ts->prop, + touches[i].x, touches[i].y, true); + } + + input_mt_sync_frame(ts->input); + input_sync(ts->input); +} + +static void ektf2127_report2_contact(struct ektf2127_ts *ts, int slot, + const u8 *buf, bool active) +{ + input_mt_slot(ts->input, slot); + input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, active); + + if (active) { + int x = (buf[0] & 0xf0) << 4 | buf[1]; + int y = (buf[0] & 0x0f) << 8 | buf[2]; + + touchscreen_report_pos(ts->input, &ts->prop, x, y, true); + } +} + +static void ektf2127_report2_event(struct ektf2127_ts *ts, const u8 *buf) +{ + ektf2127_report2_contact(ts, 0, &buf[1], !!(buf[7] & BIT(ts->status_shift))); + ektf2127_report2_contact(ts, 1, &buf[4], !!(buf[7] & BIT(ts->status_shift + 1))); + + input_mt_sync_frame(ts->input); + input_sync(ts->input); +} + +static irqreturn_t ektf2127_irq(int irq, void *dev_id) +{ + struct ektf2127_ts *ts = dev_id; + struct device *dev = &ts->client->dev; + char buf[EKTF2127_TOUCH_REPORT_SIZE]; + int ret; + + ret = i2c_master_recv(ts->client, buf, EKTF2127_TOUCH_REPORT_SIZE); + if (ret != EKTF2127_TOUCH_REPORT_SIZE) { + dev_err(dev, "Error reading touch data: %d\n", ret); + goto out; + } + + switch (buf[0]) { + case EKTF2127_REPORT: + ektf2127_report_event(ts, buf); + break; + + case EKTF2127_REPORT2: + ektf2127_report2_event(ts, buf); + break; + + case EKTF2127_NOISE: + if (buf[1] == EKTF2127_ENV_NOISY) + dev_dbg(dev, "Environment is electrically noisy\n"); + break; + + case EKTF2127_HELLO: + case EKTF2127_CALIB_DONE: + break; + + default: + dev_err(dev, "Unexpected packet header byte %#02x\n", buf[0]); + break; + } + +out: + return IRQ_HANDLED; +} + +static int ektf2127_start(struct input_dev *dev) +{ + struct ektf2127_ts *ts = input_get_drvdata(dev); + + enable_irq(ts->client->irq); + gpiod_set_value_cansleep(ts->power_gpios, 1); + + return 0; +} + +static void ektf2127_stop(struct input_dev *dev) +{ + struct ektf2127_ts *ts = input_get_drvdata(dev); + + disable_irq(ts->client->irq); + gpiod_set_value_cansleep(ts->power_gpios, 0); +} + +static int ektf2127_suspend(struct device *dev) +{ + struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev)); + + guard(mutex)(&ts->input->mutex); + + if (input_device_enabled(ts->input)) + ektf2127_stop(ts->input); + + return 0; +} + +static int ektf2127_resume(struct device *dev) +{ + struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev)); + + guard(mutex)(&ts->input->mutex); + + if (input_device_enabled(ts->input)) + ektf2127_start(ts->input); + + return 0; +} + +static DEFINE_SIMPLE_DEV_PM_OPS(ektf2127_pm_ops, ektf2127_suspend, + ektf2127_resume); + +static int ektf2127_query_dimension(struct i2c_client *client, bool width) +{ + struct device *dev = &client->dev; + const char *what = width ? "width" : "height"; + u8 what_code = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT; + u8 buf[4]; + int ret; + int error; + + /* Request dimension */ + buf[0] = EKTF2127_REQUEST; + buf[1] = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT; + buf[2] = 0x00; + buf[3] = 0x00; + ret = i2c_master_send(client, buf, sizeof(buf)); + if (ret != sizeof(buf)) { + error = ret < 0 ? ret : -EIO; + dev_err(dev, "Failed to request %s: %d\n", what, error); + return error; + } + + msleep(20); + + /* Read response */ + ret = i2c_master_recv(client, buf, sizeof(buf)); + if (ret != sizeof(buf)) { + error = ret < 0 ? ret : -EIO; + dev_err(dev, "Failed to receive %s data: %d\n", what, error); + return error; + } + + if (buf[0] != EKTF2127_RESPONSE || buf[1] != what_code) { + dev_err(dev, "Unexpected %s data: %#02x %#02x\n", + what, buf[0], buf[1]); + return -EIO; + } + + return (((buf[3] & 0xf0) << 4) | buf[2]) - 1; +} + +static int ektf2127_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + const struct ektf2127_i2c_chip_data *chip_data; + struct ektf2127_ts *ts; + struct input_dev *input; + u8 buf[4]; + int max_x, max_y; + int error; + + if (!client->irq) { + dev_err(dev, "Error no irq specified\n"); + return -EINVAL; + } + + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL); + if (!ts) + return -ENOMEM; + + /* This requests the gpio *and* turns on the touchscreen controller */ + ts->power_gpios = devm_gpiod_get(dev, "power", GPIOD_OUT_HIGH); + if (IS_ERR(ts->power_gpios)) + return dev_err_probe(dev, PTR_ERR(ts->power_gpios), "Error getting power gpio\n"); + + input = devm_input_allocate_device(dev); + if (!input) + return -ENOMEM; + + input->name = client->name; + input->id.bustype = BUS_I2C; + input->open = ektf2127_start; + input->close = ektf2127_stop; + + ts->client = client; + + /* Read hello (ignore result, depends on initial power state) */ + msleep(20); + i2c_master_recv(ts->client, buf, sizeof(buf)); + + /* Read resolution from chip */ + max_x = ektf2127_query_dimension(client, true); + if (max_x < 0) + return max_x; + + max_y = ektf2127_query_dimension(client, false); + if (max_y < 0) + return max_y; + + input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_x, 0, 0); + input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_y, 0, 0); + touchscreen_parse_properties(input, true, &ts->prop); + + error = input_mt_init_slots(input, EKTF2127_MAX_TOUCHES, + INPUT_MT_DIRECT | + INPUT_MT_DROP_UNUSED | + INPUT_MT_TRACK); + if (error) + return error; + + ts->input = input; + + chip_data = i2c_get_match_data(client); + if (!chip_data) + return dev_err_probe(&client->dev, -EINVAL, "missing chip data\n"); + + ts->status_shift = chip_data->status_shift; + + input_set_drvdata(input, ts); + + error = devm_request_threaded_irq(dev, client->irq, + NULL, ektf2127_irq, + IRQF_ONESHOT, client->name, ts); + if (error) { + dev_err(dev, "Error requesting irq: %d\n", error); + return error; + } + + /* Stop device till opened */ + ektf2127_stop(ts->input); + + error = input_register_device(input); + if (error) + return error; + + i2c_set_clientdata(client, ts); + + return 0; +} + +static const struct ektf2127_i2c_chip_data ektf2127_data = { + .status_shift = 1, +}; + +static const struct ektf2127_i2c_chip_data ektf2232_data = { + .status_shift = 0, +}; + +#ifdef CONFIG_OF +static const struct of_device_id ektf2127_of_match[] = { + { .compatible = "elan,ektf2127", .data = &ektf2127_data}, + { .compatible = "elan,ektf2132", .data = &ektf2127_data}, + { .compatible = "elan,ektf2232", .data = &ektf2232_data}, + {} +}; +MODULE_DEVICE_TABLE(of, ektf2127_of_match); +#endif + +static const struct i2c_device_id ektf2127_i2c_id[] = { + { .name = "ektf2127", .driver_data = (long)&ektf2127_data }, + { .name = "ektf2132", .driver_data = (long)&ektf2127_data }, + { .name = "ektf2232", .driver_data = (long)&ektf2232_data }, + {} +}; +MODULE_DEVICE_TABLE(i2c, ektf2127_i2c_id); + +static struct i2c_driver ektf2127_driver = { + .driver = { + .name = "elan_ektf2127", + .pm = pm_sleep_ptr(&ektf2127_pm_ops), + .of_match_table = of_match_ptr(ektf2127_of_match), + }, + .probe = ektf2127_probe, + .id_table = ektf2127_i2c_id, +}; +module_i2c_driver(ektf2127_driver); + +MODULE_DESCRIPTION("ELAN eKTF2127/eKTF2132 I2C Touchscreen Driver"); +MODULE_AUTHOR("Michel Verlaan, Siebren Vroegindeweij"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1