110494dceSDaniel Mack /* 210494dceSDaniel Mack * Touch Screen driver for EETI's I2C connected touch screen panels 310494dceSDaniel Mack * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de> 410494dceSDaniel Mack * 510494dceSDaniel Mack * See EETI's software guide for the protocol specification: 610494dceSDaniel Mack * http://home.eeti.com.tw/web20/eg/guide.htm 710494dceSDaniel Mack * 810494dceSDaniel Mack * Based on migor_ts.c 910494dceSDaniel Mack * Copyright (c) 2008 Magnus Damm 1010494dceSDaniel Mack * Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com> 1110494dceSDaniel Mack * 1210494dceSDaniel Mack * This file is free software; you can redistribute it and/or 1310494dceSDaniel Mack * modify it under the terms of the GNU General Public 1410494dceSDaniel Mack * License as published by the Free Software Foundation; either 1510494dceSDaniel Mack * version 2 of the License, or (at your option) any later version. 1610494dceSDaniel Mack * 1710494dceSDaniel Mack * This file is distributed in the hope that it will be useful, 1810494dceSDaniel Mack * but WITHOUT ANY WARRANTY; without even the implied warranty of 1910494dceSDaniel Mack * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 2010494dceSDaniel Mack * General Public License for more details. 2110494dceSDaniel Mack * 2210494dceSDaniel Mack * You should have received a copy of the GNU General Public 2310494dceSDaniel Mack * License along with this library; if not, write to the Free Software 2410494dceSDaniel Mack * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 2510494dceSDaniel Mack */ 2610494dceSDaniel Mack 2710494dceSDaniel Mack #include <linux/module.h> 2810494dceSDaniel Mack #include <linux/moduleparam.h> 2910494dceSDaniel Mack #include <linux/kernel.h> 3010494dceSDaniel Mack #include <linux/input.h> 3110494dceSDaniel Mack #include <linux/interrupt.h> 3210494dceSDaniel Mack #include <linux/i2c.h> 3310494dceSDaniel Mack #include <linux/timer.h> 34d99caa47SDmitry Torokhov #include <linux/gpio/consumer.h> 355a0e3ad6STejun Heo #include <linux/slab.h> 36e9f66cdbSDmitry Torokhov #include <asm/unaligned.h> 3710494dceSDaniel Mack 3890ab5ee9SRusty Russell static bool flip_x; 3910494dceSDaniel Mack module_param(flip_x, bool, 0644); 4010494dceSDaniel Mack MODULE_PARM_DESC(flip_x, "flip x coordinate"); 4110494dceSDaniel Mack 4290ab5ee9SRusty Russell static bool flip_y; 4310494dceSDaniel Mack module_param(flip_y, bool, 0644); 4410494dceSDaniel Mack MODULE_PARM_DESC(flip_y, "flip y coordinate"); 4510494dceSDaniel Mack 46720bebdfSDmitry Torokhov struct eeti_ts { 4710494dceSDaniel Mack struct i2c_client *client; 4810494dceSDaniel Mack struct input_dev *input; 49d99caa47SDmitry Torokhov struct gpio_desc *attn_gpio; 500378008aSDmitry Torokhov bool running; 5110494dceSDaniel Mack }; 5210494dceSDaniel Mack 5310494dceSDaniel Mack #define EETI_TS_BITDEPTH (11) 5410494dceSDaniel Mack #define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1) 5510494dceSDaniel Mack 56272c03bbSDmitry Torokhov #define REPORT_BIT_PRESSED BIT(0) 57272c03bbSDmitry Torokhov #define REPORT_BIT_AD0 BIT(1) 58272c03bbSDmitry Torokhov #define REPORT_BIT_AD1 BIT(2) 59272c03bbSDmitry Torokhov #define REPORT_BIT_HAS_PRESSURE BIT(6) 6010494dceSDaniel Mack #define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH) 6110494dceSDaniel Mack 620378008aSDmitry Torokhov static void eeti_ts_report_event(struct eeti_ts *eeti, u8 *buf) 6310494dceSDaniel Mack { 640378008aSDmitry Torokhov unsigned int res; 650378008aSDmitry Torokhov u16 x, y; 6610494dceSDaniel Mack 6710494dceSDaniel Mack res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1)); 68e9f66cdbSDmitry Torokhov 69e9f66cdbSDmitry Torokhov x = get_unaligned_be16(&buf[1]); 70e9f66cdbSDmitry Torokhov y = get_unaligned_be16(&buf[3]); 7110494dceSDaniel Mack 7210494dceSDaniel Mack /* fix the range to 11 bits */ 7310494dceSDaniel Mack x >>= res - EETI_TS_BITDEPTH; 7410494dceSDaniel Mack y >>= res - EETI_TS_BITDEPTH; 7510494dceSDaniel Mack 7610494dceSDaniel Mack if (flip_x) 7710494dceSDaniel Mack x = EETI_MAXVAL - x; 7810494dceSDaniel Mack 7910494dceSDaniel Mack if (flip_y) 8010494dceSDaniel Mack y = EETI_MAXVAL - y; 8110494dceSDaniel Mack 8210494dceSDaniel Mack if (buf[0] & REPORT_BIT_HAS_PRESSURE) 83720bebdfSDmitry Torokhov input_report_abs(eeti->input, ABS_PRESSURE, buf[5]); 8410494dceSDaniel Mack 85720bebdfSDmitry Torokhov input_report_abs(eeti->input, ABS_X, x); 86720bebdfSDmitry Torokhov input_report_abs(eeti->input, ABS_Y, y); 870378008aSDmitry Torokhov input_report_key(eeti->input, BTN_TOUCH, buf[0] & REPORT_BIT_PRESSED); 88720bebdfSDmitry Torokhov input_sync(eeti->input); 8910494dceSDaniel Mack } 9010494dceSDaniel Mack 9110494dceSDaniel Mack static irqreturn_t eeti_ts_isr(int irq, void *dev_id) 9210494dceSDaniel Mack { 93720bebdfSDmitry Torokhov struct eeti_ts *eeti = dev_id; 940378008aSDmitry Torokhov int len; 950378008aSDmitry Torokhov int error; 960378008aSDmitry Torokhov char buf[6]; 9710494dceSDaniel Mack 980378008aSDmitry Torokhov do { 990378008aSDmitry Torokhov len = i2c_master_recv(eeti->client, buf, sizeof(buf)); 1000378008aSDmitry Torokhov if (len != sizeof(buf)) { 1010378008aSDmitry Torokhov error = len < 0 ? len : -EIO; 1020378008aSDmitry Torokhov dev_err(&eeti->client->dev, 1030378008aSDmitry Torokhov "failed to read touchscreen data: %d\n", 1040378008aSDmitry Torokhov error); 1050378008aSDmitry Torokhov break; 1060378008aSDmitry Torokhov } 1070378008aSDmitry Torokhov 1080378008aSDmitry Torokhov if (buf[0] & 0x80) { 1090378008aSDmitry Torokhov /* Motion packet */ 1100378008aSDmitry Torokhov eeti_ts_report_event(eeti, buf); 1110378008aSDmitry Torokhov } 112d99caa47SDmitry Torokhov } while (eeti->running && 113d99caa47SDmitry Torokhov eeti->attn_gpio && gpiod_get_value_cansleep(eeti->attn_gpio)); 11410494dceSDaniel Mack 11510494dceSDaniel Mack return IRQ_HANDLED; 11610494dceSDaniel Mack } 11710494dceSDaniel Mack 118720bebdfSDmitry Torokhov static void eeti_ts_start(struct eeti_ts *eeti) 11910494dceSDaniel Mack { 1200378008aSDmitry Torokhov eeti->running = true; 1210378008aSDmitry Torokhov wmb(); 1222d388499SDmitry Torokhov enable_irq(eeti->client->irq); 1237fbef0d1SDaniel Mack } 1247fbef0d1SDaniel Mack 125720bebdfSDmitry Torokhov static void eeti_ts_stop(struct eeti_ts *eeti) 1267fbef0d1SDaniel Mack { 1270378008aSDmitry Torokhov eeti->running = false; 1280378008aSDmitry Torokhov wmb(); 1292d388499SDmitry Torokhov disable_irq(eeti->client->irq); 1307fbef0d1SDaniel Mack } 1317fbef0d1SDaniel Mack 1327fbef0d1SDaniel Mack static int eeti_ts_open(struct input_dev *dev) 1337fbef0d1SDaniel Mack { 134720bebdfSDmitry Torokhov struct eeti_ts *eeti = input_get_drvdata(dev); 1357fbef0d1SDaniel Mack 136720bebdfSDmitry Torokhov eeti_ts_start(eeti); 13710494dceSDaniel Mack 13810494dceSDaniel Mack return 0; 13910494dceSDaniel Mack } 14010494dceSDaniel Mack 14110494dceSDaniel Mack static void eeti_ts_close(struct input_dev *dev) 14210494dceSDaniel Mack { 143720bebdfSDmitry Torokhov struct eeti_ts *eeti = input_get_drvdata(dev); 14410494dceSDaniel Mack 145720bebdfSDmitry Torokhov eeti_ts_stop(eeti); 14610494dceSDaniel Mack } 14710494dceSDaniel Mack 1485298cc4cSBill Pemberton static int eeti_ts_probe(struct i2c_client *client, 14910494dceSDaniel Mack const struct i2c_device_id *idp) 15010494dceSDaniel Mack { 1516f9fab69SDmitry Torokhov struct device *dev = &client->dev; 152720bebdfSDmitry Torokhov struct eeti_ts *eeti; 15310494dceSDaniel Mack struct input_dev *input; 1546f9fab69SDmitry Torokhov int error; 15510494dceSDaniel Mack 1567fbef0d1SDaniel Mack /* 1577fbef0d1SDaniel Mack * In contrast to what's described in the datasheet, there seems 15810494dceSDaniel Mack * to be no way of probing the presence of that device using I2C 15910494dceSDaniel Mack * commands. So we need to blindly believe it is there, and wait 1607fbef0d1SDaniel Mack * for interrupts to occur. 1617fbef0d1SDaniel Mack */ 16210494dceSDaniel Mack 1636f9fab69SDmitry Torokhov eeti = devm_kzalloc(dev, sizeof(*eeti), GFP_KERNEL); 164720bebdfSDmitry Torokhov if (!eeti) { 1656f9fab69SDmitry Torokhov dev_err(dev, "failed to allocate driver data\n"); 166ad03ae44SGuenter Roeck return -ENOMEM; 16710494dceSDaniel Mack } 16810494dceSDaniel Mack 1696f9fab69SDmitry Torokhov input = devm_input_allocate_device(dev); 17010494dceSDaniel Mack if (!input) { 1716f9fab69SDmitry Torokhov dev_err(dev, "Failed to allocate input device.\n"); 1726f9fab69SDmitry Torokhov return -ENOMEM; 17310494dceSDaniel Mack } 17410494dceSDaniel Mack 17542e02a6aSDmitry Torokhov input_set_capability(input, EV_KEY, BTN_TOUCH); 17610494dceSDaniel Mack 17710494dceSDaniel Mack input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0); 17810494dceSDaniel Mack input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0); 17910494dceSDaniel Mack input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0); 18010494dceSDaniel Mack 18110494dceSDaniel Mack input->name = client->name; 18210494dceSDaniel Mack input->id.bustype = BUS_I2C; 18310494dceSDaniel Mack input->open = eeti_ts_open; 18410494dceSDaniel Mack input->close = eeti_ts_close; 18510494dceSDaniel Mack 186720bebdfSDmitry Torokhov eeti->client = client; 187720bebdfSDmitry Torokhov eeti->input = input; 18810494dceSDaniel Mack 189d99caa47SDmitry Torokhov eeti->attn_gpio = devm_gpiod_get_optional(dev, "attn", GPIOD_IN); 190d99caa47SDmitry Torokhov if (IS_ERR(eeti->attn_gpio)) 191d99caa47SDmitry Torokhov return PTR_ERR(eeti->attn_gpio); 19225a70e38SDaniel Mack 193720bebdfSDmitry Torokhov i2c_set_clientdata(client, eeti); 194720bebdfSDmitry Torokhov input_set_drvdata(input, eeti); 19510494dceSDaniel Mack 1960378008aSDmitry Torokhov error = devm_request_threaded_irq(dev, client->irq, 1970378008aSDmitry Torokhov NULL, eeti_ts_isr, 198d422be5fSDmitry Torokhov IRQF_ONESHOT, 199720bebdfSDmitry Torokhov client->name, eeti); 2006f9fab69SDmitry Torokhov if (error) { 2016f9fab69SDmitry Torokhov dev_err(dev, "Unable to request touchscreen IRQ: %d\n", 2026f9fab69SDmitry Torokhov error); 2036f9fab69SDmitry Torokhov return error; 20410494dceSDaniel Mack } 20510494dceSDaniel Mack 2067fbef0d1SDaniel Mack /* 2077fbef0d1SDaniel Mack * Disable the device for now. It will be enabled once the 2087fbef0d1SDaniel Mack * input device is opened. 2097fbef0d1SDaniel Mack */ 210720bebdfSDmitry Torokhov eeti_ts_stop(eeti); 21110494dceSDaniel Mack 2120378008aSDmitry Torokhov error = input_register_device(input); 2130378008aSDmitry Torokhov if (error) 2140378008aSDmitry Torokhov return error; 2150378008aSDmitry Torokhov 21610494dceSDaniel Mack return 0; 21710494dceSDaniel Mack } 21810494dceSDaniel Mack 21902b6a58bSJingoo Han static int __maybe_unused eeti_ts_suspend(struct device *dev) 22010494dceSDaniel Mack { 22185012fffSMark Brown struct i2c_client *client = to_i2c_client(dev); 222720bebdfSDmitry Torokhov struct eeti_ts *eeti = i2c_get_clientdata(client); 223720bebdfSDmitry Torokhov struct input_dev *input_dev = eeti->input; 2247fbef0d1SDaniel Mack 2257fbef0d1SDaniel Mack mutex_lock(&input_dev->mutex); 2267fbef0d1SDaniel Mack 2277fbef0d1SDaniel Mack if (input_dev->users) 228720bebdfSDmitry Torokhov eeti_ts_stop(eeti); 2297fbef0d1SDaniel Mack 2307fbef0d1SDaniel Mack mutex_unlock(&input_dev->mutex); 23110494dceSDaniel Mack 23210494dceSDaniel Mack if (device_may_wakeup(&client->dev)) 2332d388499SDmitry Torokhov enable_irq_wake(client->irq); 23410494dceSDaniel Mack 23510494dceSDaniel Mack return 0; 23610494dceSDaniel Mack } 23710494dceSDaniel Mack 23802b6a58bSJingoo Han static int __maybe_unused eeti_ts_resume(struct device *dev) 23910494dceSDaniel Mack { 24085012fffSMark Brown struct i2c_client *client = to_i2c_client(dev); 241720bebdfSDmitry Torokhov struct eeti_ts *eeti = i2c_get_clientdata(client); 242720bebdfSDmitry Torokhov struct input_dev *input_dev = eeti->input; 24310494dceSDaniel Mack 24410494dceSDaniel Mack if (device_may_wakeup(&client->dev)) 2452d388499SDmitry Torokhov disable_irq_wake(client->irq); 24610494dceSDaniel Mack 2477fbef0d1SDaniel Mack mutex_lock(&input_dev->mutex); 2487fbef0d1SDaniel Mack 2497fbef0d1SDaniel Mack if (input_dev->users) 250720bebdfSDmitry Torokhov eeti_ts_start(eeti); 2517fbef0d1SDaniel Mack 2527fbef0d1SDaniel Mack mutex_unlock(&input_dev->mutex); 2537fbef0d1SDaniel Mack 25410494dceSDaniel Mack return 0; 25510494dceSDaniel Mack } 25685012fffSMark Brown 25785012fffSMark Brown static SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume); 25810494dceSDaniel Mack 25910494dceSDaniel Mack static const struct i2c_device_id eeti_ts_id[] = { 26010494dceSDaniel Mack { "eeti_ts", 0 }, 26110494dceSDaniel Mack { } 26210494dceSDaniel Mack }; 26310494dceSDaniel Mack MODULE_DEVICE_TABLE(i2c, eeti_ts_id); 26410494dceSDaniel Mack 26510494dceSDaniel Mack static struct i2c_driver eeti_ts_driver = { 26610494dceSDaniel Mack .driver = { 26710494dceSDaniel Mack .name = "eeti_ts", 26885012fffSMark Brown .pm = &eeti_ts_pm, 26910494dceSDaniel Mack }, 27010494dceSDaniel Mack .probe = eeti_ts_probe, 27110494dceSDaniel Mack .id_table = eeti_ts_id, 27210494dceSDaniel Mack }; 27310494dceSDaniel Mack 2741b92c1cfSAxel Lin module_i2c_driver(eeti_ts_driver); 27510494dceSDaniel Mack 27610494dceSDaniel Mack MODULE_DESCRIPTION("EETI Touchscreen driver"); 27710494dceSDaniel Mack MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); 27810494dceSDaniel Mack MODULE_LICENSE("GPL"); 279