diff options
Diffstat (limited to 'drivers/input/touchscreen/egalax_ts_serial.c')
| -rw-r--r-- | drivers/input/touchscreen/egalax_ts_serial.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/egalax_ts_serial.c b/drivers/input/touchscreen/egalax_ts_serial.c new file mode 100644 index 000000000..657bbae60 --- /dev/null +++ b/drivers/input/touchscreen/egalax_ts_serial.c @@ -0,0 +1,194 @@ +/* + * EETI Egalax serial touchscreen driver + * + * Copyright (c) 2015 Zoltán Böszörményi <zboszor@pr.hu> + * + * based on the + * + * Hampshire serial touchscreen driver (Copyright (c) 2010 Adam Bennett) + */ + +/* + * 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/errno.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/input.h> +#include <linux/serio.h> + +#define DRIVER_DESC "EETI Egalax serial touchscreen driver" + +/* + * Definitions & global arrays. + */ + +#define EGALAX_FORMAT_MAX_LENGTH 6 +#define EGALAX_FORMAT_START_BIT BIT(7) +#define EGALAX_FORMAT_PRESSURE_BIT BIT(6) +#define EGALAX_FORMAT_TOUCH_BIT BIT(0) +#define EGALAX_FORMAT_RESOLUTION_MASK 0x06 + +#define EGALAX_MIN_XC 0 +#define EGALAX_MAX_XC 0x4000 +#define EGALAX_MIN_YC 0 +#define EGALAX_MAX_YC 0x4000 + +/* + * Per-touchscreen data. + */ +struct egalax { + struct input_dev *input; + struct serio *serio; + int idx; + u8 data[EGALAX_FORMAT_MAX_LENGTH]; + char phys[32]; +}; + +static void egalax_process_data(struct egalax *egalax) +{ + struct input_dev *dev = egalax->input; + u8 *data = egalax->data; + u16 x, y; + u8 shift; + u8 mask; + + shift = 3 - ((data[0] & EGALAX_FORMAT_RESOLUTION_MASK) >> 1); + mask = 0xff >> (shift + 1); + + x = (((u16)(data[1] & mask) << 7) | (data[2] & 0x7f)) << shift; + y = (((u16)(data[3] & mask) << 7) | (data[4] & 0x7f)) << shift; + + input_report_key(dev, BTN_TOUCH, data[0] & EGALAX_FORMAT_TOUCH_BIT); + input_report_abs(dev, ABS_X, x); + input_report_abs(dev, ABS_Y, y); + input_sync(dev); +} + +static irqreturn_t egalax_interrupt(struct serio *serio, + unsigned char data, unsigned int flags) +{ + struct egalax *egalax = serio_get_drvdata(serio); + int pkt_len; + + egalax->data[egalax->idx++] = data; + + if (likely(egalax->data[0] & EGALAX_FORMAT_START_BIT)) { + pkt_len = egalax->data[0] & EGALAX_FORMAT_PRESSURE_BIT ? 6 : 5; + if (pkt_len == egalax->idx) { + egalax_process_data(egalax); + egalax->idx = 0; + } + } else { + dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n", + egalax->data[0]); + egalax->idx = 0; + } + + return IRQ_HANDLED; +} + +/* + * egalax_connect() is the routine that is called when someone adds a + * new serio device that supports egalax protocol and registers it as + * an input device. This is usually accomplished using inputattach. + */ +static int egalax_connect(struct serio *serio, struct serio_driver *drv) +{ + struct egalax *egalax; + struct input_dev *input_dev; + int error; + + egalax = kzalloc(sizeof(struct egalax), GFP_KERNEL); + input_dev = input_allocate_device(); + if (!egalax || !input_dev) { + error = -ENOMEM; + goto err_free_mem; + } + + egalax->serio = serio; + egalax->input = input_dev; + snprintf(egalax->phys, sizeof(egalax->phys), + "%s/input0", serio->phys); + + input_dev->name = "EETI eGalaxTouch Serial TouchScreen"; + input_dev->phys = egalax->phys; + input_dev->id.bustype = BUS_RS232; + input_dev->id.vendor = SERIO_EGALAX; + input_dev->id.product = 0; + input_dev->id.version = 0x0001; + input_dev->dev.parent = &serio->dev; + + input_set_capability(input_dev, EV_KEY, BTN_TOUCH); + input_set_abs_params(input_dev, ABS_X, + EGALAX_MIN_XC, EGALAX_MAX_XC, 0, 0); + input_set_abs_params(input_dev, ABS_Y, + EGALAX_MIN_YC, EGALAX_MAX_YC, 0, 0); + + serio_set_drvdata(serio, egalax); + + error = serio_open(serio, drv); + if (error) + goto err_reset_drvdata; + + error = input_register_device(input_dev); + if (error) + goto err_close_serio; + + return 0; + +err_close_serio: + serio_close(serio); +err_reset_drvdata: + serio_set_drvdata(serio, NULL); +err_free_mem: + input_free_device(input_dev); + kfree(egalax); + return error; +} + +static void egalax_disconnect(struct serio *serio) +{ + struct egalax *egalax = serio_get_drvdata(serio); + + serio_close(serio); + serio_set_drvdata(serio, NULL); + input_unregister_device(egalax->input); + kfree(egalax); +} + +/* + * The serio driver structure. + */ + +static const struct serio_device_id egalax_serio_ids[] = { + { + .type = SERIO_RS232, + .proto = SERIO_EGALAX, + .id = SERIO_ANY, + .extra = SERIO_ANY, + }, + { 0 } +}; + +MODULE_DEVICE_TABLE(serio, egalax_serio_ids); + +static struct serio_driver egalax_drv = { + .driver = { + .name = "egalax", + }, + .description = DRIVER_DESC, + .id_table = egalax_serio_ids, + .interrupt = egalax_interrupt, + .connect = egalax_connect, + .disconnect = egalax_disconnect, +}; +module_serio_driver(egalax_drv); + +MODULE_AUTHOR("Zoltán Böszörményi <zboszor@pr.hu>"); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL v2"); |