diff options
Diffstat (limited to 'drivers/input/touchscreen/tsc40.c')
| -rw-r--r-- | drivers/input/touchscreen/tsc40.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/tsc40.c b/drivers/input/touchscreen/tsc40.c new file mode 100644 index 0000000000..1395770214 --- /dev/null +++ b/drivers/input/touchscreen/tsc40.c @@ -0,0 +1,172 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TSC-40 serial touchscreen driver. It should be compatible with + * TSC-10 and 25. + * + * Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/input.h> +#include <linux/serio.h> + +#define PACKET_LENGTH 5 +struct tsc_ser { + struct input_dev *dev; + struct serio *serio; + u32 idx; + unsigned char data[PACKET_LENGTH]; + char phys[32]; +}; + +static void tsc_process_data(struct tsc_ser *ptsc) +{ + struct input_dev *dev = ptsc->dev; + u8 *data = ptsc->data; + u32 x; + u32 y; + + x = ((data[1] & 0x03) << 8) | data[2]; + y = ((data[3] & 0x03) << 8) | data[4]; + + input_report_abs(dev, ABS_X, x); + input_report_abs(dev, ABS_Y, y); + input_report_key(dev, BTN_TOUCH, 1); + + input_sync(dev); +} + +static irqreturn_t tsc_interrupt(struct serio *serio, + unsigned char data, unsigned int flags) +{ + struct tsc_ser *ptsc = serio_get_drvdata(serio); + struct input_dev *dev = ptsc->dev; + + ptsc->data[ptsc->idx] = data; + switch (ptsc->idx++) { + case 0: + if (unlikely((data & 0x3e) != 0x10)) { + dev_dbg(&serio->dev, + "unsynchronized packet start (0x%02x)\n", data); + ptsc->idx = 0; + } else if (!(data & 0x01)) { + input_report_key(dev, BTN_TOUCH, 0); + input_sync(dev); + ptsc->idx = 0; + } + break; + + case 1: + case 3: + if (unlikely(data & 0xfc)) { + dev_dbg(&serio->dev, + "unsynchronized data 0x%02x at offset %d\n", + data, ptsc->idx - 1); + ptsc->idx = 0; + } + break; + + case 4: + tsc_process_data(ptsc); + ptsc->idx = 0; + break; + } + + return IRQ_HANDLED; +} + +static int tsc_connect(struct serio *serio, struct serio_driver *drv) +{ + struct tsc_ser *ptsc; + struct input_dev *input_dev; + int error; + + ptsc = kzalloc(sizeof(struct tsc_ser), GFP_KERNEL); + input_dev = input_allocate_device(); + if (!ptsc || !input_dev) { + error = -ENOMEM; + goto fail1; + } + + ptsc->serio = serio; + ptsc->dev = input_dev; + snprintf(ptsc->phys, sizeof(ptsc->phys), "%s/input0", serio->phys); + + input_dev->name = "TSC-10/25/40 Serial TouchScreen"; + input_dev->phys = ptsc->phys; + input_dev->id.bustype = BUS_RS232; + input_dev->id.vendor = SERIO_TSC40; + input_dev->id.product = 40; + input_dev->id.version = 0x0001; + input_dev->dev.parent = &serio->dev; + + input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); + __set_bit(BTN_TOUCH, input_dev->keybit); + input_set_abs_params(ptsc->dev, ABS_X, 0, 0x3ff, 0, 0); + input_set_abs_params(ptsc->dev, ABS_Y, 0, 0x3ff, 0, 0); + + serio_set_drvdata(serio, ptsc); + + error = serio_open(serio, drv); + if (error) + goto fail2; + + error = input_register_device(ptsc->dev); + if (error) + goto fail3; + + return 0; + +fail3: + serio_close(serio); +fail2: + serio_set_drvdata(serio, NULL); +fail1: + input_free_device(input_dev); + kfree(ptsc); + return error; +} + +static void tsc_disconnect(struct serio *serio) +{ + struct tsc_ser *ptsc = serio_get_drvdata(serio); + + serio_close(serio); + + input_unregister_device(ptsc->dev); + kfree(ptsc); + + serio_set_drvdata(serio, NULL); +} + +static const struct serio_device_id tsc_serio_ids[] = { + { + .type = SERIO_RS232, + .proto = SERIO_TSC40, + .id = SERIO_ANY, + .extra = SERIO_ANY, + }, + { 0 } +}; +MODULE_DEVICE_TABLE(serio, tsc_serio_ids); + +#define DRIVER_DESC "TSC-10/25/40 serial touchscreen driver" + +static struct serio_driver tsc_drv = { + .driver = { + .name = "tsc40", + }, + .description = DRIVER_DESC, + .id_table = tsc_serio_ids, + .interrupt = tsc_interrupt, + .connect = tsc_connect, + .disconnect = tsc_disconnect, +}; + +module_serio_driver(tsc_drv); + +MODULE_AUTHOR("Sebastian Andrzej Siewior <bigeasy@linutronix.de>"); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL v2"); |