diff options
Diffstat (limited to 'drivers/input/touchscreen/eeti_ts.c')
| -rw-r--r-- | drivers/input/touchscreen/eeti_ts.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/eeti_ts.c b/drivers/input/touchscreen/eeti_ts.c new file mode 100644 index 0000000000..5e4167f6c6 --- /dev/null +++ b/drivers/input/touchscreen/eeti_ts.c @@ -0,0 +1,302 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Touch Screen driver for EETI's I2C connected touch screen panels + * Copyright (c) 2009,2018 Daniel Mack <daniel@zonque.org> + * + * See EETI's software guide for the protocol specification: + * http://home.eeti.com.tw/documentation.html + * + * Based on migor_ts.c + * Copyright (c) 2008 Magnus Damm + * Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com> + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/input.h> +#include <linux/input/touchscreen.h> +#include <linux/interrupt.h> +#include <linux/i2c.h> +#include <linux/timer.h> +#include <linux/gpio/consumer.h> +#include <linux/of.h> +#include <linux/slab.h> +#include <asm/unaligned.h> + +struct eeti_ts { + struct i2c_client *client; + struct input_dev *input; + struct gpio_desc *attn_gpio; + struct touchscreen_properties props; + struct mutex mutex; + bool running; +}; + +#define EETI_TS_BITDEPTH (11) +#define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1) + +#define REPORT_BIT_PRESSED BIT(0) +#define REPORT_BIT_AD0 BIT(1) +#define REPORT_BIT_AD1 BIT(2) +#define REPORT_BIT_HAS_PRESSURE BIT(6) +#define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH) + +static void eeti_ts_report_event(struct eeti_ts *eeti, u8 *buf) +{ + unsigned int res; + u16 x, y; + + res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1)); + + x = get_unaligned_be16(&buf[1]); + y = get_unaligned_be16(&buf[3]); + + /* fix the range to 11 bits */ + x >>= res - EETI_TS_BITDEPTH; + y >>= res - EETI_TS_BITDEPTH; + + if (buf[0] & REPORT_BIT_HAS_PRESSURE) + input_report_abs(eeti->input, ABS_PRESSURE, buf[5]); + + touchscreen_report_pos(eeti->input, &eeti->props, x, y, false); + input_report_key(eeti->input, BTN_TOUCH, buf[0] & REPORT_BIT_PRESSED); + input_sync(eeti->input); +} + +static int eeti_ts_read(struct eeti_ts *eeti) +{ + int len, error; + char buf[6]; + + len = i2c_master_recv(eeti->client, buf, sizeof(buf)); + if (len != sizeof(buf)) { + error = len < 0 ? len : -EIO; + dev_err(&eeti->client->dev, + "failed to read touchscreen data: %d\n", + error); + return error; + } + + /* Motion packet */ + if (buf[0] & 0x80) + eeti_ts_report_event(eeti, buf); + + return 0; +} + +static irqreturn_t eeti_ts_isr(int irq, void *dev_id) +{ + struct eeti_ts *eeti = dev_id; + int error; + + mutex_lock(&eeti->mutex); + + do { + /* + * If we have attention GPIO, trust it. Otherwise we'll read + * once and exit. We assume that in this case we are using + * level triggered interrupt and it will get raised again + * if/when there is more data. + */ + if (eeti->attn_gpio && + !gpiod_get_value_cansleep(eeti->attn_gpio)) { + break; + } + + error = eeti_ts_read(eeti); + if (error) + break; + + } while (eeti->running && eeti->attn_gpio); + + mutex_unlock(&eeti->mutex); + return IRQ_HANDLED; +} + +static void eeti_ts_start(struct eeti_ts *eeti) +{ + mutex_lock(&eeti->mutex); + + eeti->running = true; + enable_irq(eeti->client->irq); + + /* + * Kick the controller in case we are using edge interrupt and + * we missed our edge while interrupt was disabled. We expect + * the attention GPIO to be wired in this case. + */ + if (eeti->attn_gpio && gpiod_get_value_cansleep(eeti->attn_gpio)) + eeti_ts_read(eeti); + + mutex_unlock(&eeti->mutex); +} + +static void eeti_ts_stop(struct eeti_ts *eeti) +{ + /* + * Not locking here, just setting a flag and expect that the + * interrupt thread will notice the flag eventually. + */ + eeti->running = false; + wmb(); + disable_irq(eeti->client->irq); +} + +static int eeti_ts_open(struct input_dev *dev) +{ + struct eeti_ts *eeti = input_get_drvdata(dev); + + eeti_ts_start(eeti); + + return 0; +} + +static void eeti_ts_close(struct input_dev *dev) +{ + struct eeti_ts *eeti = input_get_drvdata(dev); + + eeti_ts_stop(eeti); +} + +static int eeti_ts_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + struct eeti_ts *eeti; + struct input_dev *input; + int error; + + /* + * In contrast to what's described in the datasheet, there seems + * to be no way of probing the presence of that device using I2C + * commands. So we need to blindly believe it is there, and wait + * for interrupts to occur. + */ + + eeti = devm_kzalloc(dev, sizeof(*eeti), GFP_KERNEL); + if (!eeti) { + dev_err(dev, "failed to allocate driver data\n"); + return -ENOMEM; + } + + mutex_init(&eeti->mutex); + + input = devm_input_allocate_device(dev); + if (!input) { + dev_err(dev, "Failed to allocate input device.\n"); + return -ENOMEM; + } + + input_set_capability(input, EV_KEY, BTN_TOUCH); + + input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0); + input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0); + input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0); + + touchscreen_parse_properties(input, false, &eeti->props); + + input->name = client->name; + input->id.bustype = BUS_I2C; + input->open = eeti_ts_open; + input->close = eeti_ts_close; + + eeti->client = client; + eeti->input = input; + + eeti->attn_gpio = devm_gpiod_get_optional(dev, "attn", GPIOD_IN); + if (IS_ERR(eeti->attn_gpio)) + return PTR_ERR(eeti->attn_gpio); + + i2c_set_clientdata(client, eeti); + input_set_drvdata(input, eeti); + + error = devm_request_threaded_irq(dev, client->irq, + NULL, eeti_ts_isr, + IRQF_ONESHOT, + client->name, eeti); + if (error) { + dev_err(dev, "Unable to request touchscreen IRQ: %d\n", + error); + return error; + } + + /* + * Disable the device for now. It will be enabled once the + * input device is opened. + */ + eeti_ts_stop(eeti); + + error = input_register_device(input); + if (error) + return error; + + return 0; +} + +static int eeti_ts_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct eeti_ts *eeti = i2c_get_clientdata(client); + struct input_dev *input_dev = eeti->input; + + mutex_lock(&input_dev->mutex); + + if (input_device_enabled(input_dev)) + eeti_ts_stop(eeti); + + mutex_unlock(&input_dev->mutex); + + if (device_may_wakeup(&client->dev)) + enable_irq_wake(client->irq); + + return 0; +} + +static int eeti_ts_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct eeti_ts *eeti = i2c_get_clientdata(client); + struct input_dev *input_dev = eeti->input; + + if (device_may_wakeup(&client->dev)) + disable_irq_wake(client->irq); + + mutex_lock(&input_dev->mutex); + + if (input_device_enabled(input_dev)) + eeti_ts_start(eeti); + + mutex_unlock(&input_dev->mutex); + + return 0; +} + +static DEFINE_SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume); + +static const struct i2c_device_id eeti_ts_id[] = { + { "eeti_ts", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, eeti_ts_id); + +#ifdef CONFIG_OF +static const struct of_device_id of_eeti_ts_match[] = { + { .compatible = "eeti,exc3000-i2c", }, + { } +}; +#endif + +static struct i2c_driver eeti_ts_driver = { + .driver = { + .name = "eeti_ts", + .pm = pm_sleep_ptr(&eeti_ts_pm), + .of_match_table = of_match_ptr(of_eeti_ts_match), + }, + .probe = eeti_ts_probe, + .id_table = eeti_ts_id, +}; + +module_i2c_driver(eeti_ts_driver); + +MODULE_DESCRIPTION("EETI Touchscreen driver"); +MODULE_AUTHOR("Daniel Mack <daniel@zonque.org>"); +MODULE_LICENSE("GPL"); |