| /* |
| * drivers/input/touchscreen/ak4183.c |
| * |
| * Copyright (C) 2004-2009, Ambarella, Inc. |
| * Zhenwu Xue <zwxue@ambarella.com> |
| * |
| * |
| * 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/module.h> |
| #include <linux/hrtimer.h> |
| #include <linux/slab.h> |
| #include <linux/input.h> |
| #include <linux/interrupt.h> |
| #include <linux/i2c.h> |
| #include <linux/i2c/ak4183.h> |
| |
| /* ns delay before the first sample */ |
| #define TS_POLL_DELAY (10 * 1000) |
| /* ns delay between samples */ |
| #define TS_POLL_PERIOD (5 * 1000) |
| |
| |
| #define AK4183_MEASURE_X (0xc << 4) |
| #define AK4183_MEASURE_Y (0xd << 4) |
| #define AK4183_MEASURE_Z1 (0xe << 4) |
| #define AK4183_MEASURE_Z2 (0xf << 4) |
| |
| #define AK4183_AUTO_POWER_IRQ_EN (0x0 << 2) |
| #define AK4183_ADC_ON_IRQ_DIS (0x1 << 2) |
| |
| #define AK4183_12BIT (0x0 << 1) |
| #define AK4183_8BIT (0x1 << 1) |
| |
| #define VAL_12BIT (1 << 12) |
| #define MAX_12BIT (VAL_12BIT - 1) |
| |
| #define ADC_ON_12BIT (AK4183_12BIT | AK4183_AUTO_POWER_IRQ_EN) |
| |
| #define READ_X (ADC_ON_12BIT | AK4183_MEASURE_X) |
| #define READ_Y (ADC_ON_12BIT | AK4183_MEASURE_Y) |
| #define READ_Z1 (ADC_ON_12BIT | AK4183_MEASURE_Z1) |
| #define READ_Z2 (ADC_ON_12BIT | AK4183_MEASURE_Z2) |
| |
| struct ts_event { |
| u16 x; |
| u16 y; |
| u16 z1, z2; |
| }; |
| |
| struct ak4183 { |
| struct input_dev *input; |
| char phys[32]; |
| struct hrtimer timer; |
| struct ts_event tc; |
| |
| struct workqueue_struct *workqueue; |
| struct work_struct report_worker; |
| |
| struct i2c_client *client; |
| |
| spinlock_t lock; |
| |
| u16 model; |
| u16 x_plate_ohms; |
| struct ak4183_fix_data fix; |
| |
| unsigned pendown; |
| int irq; |
| |
| int (*get_pendown_state)(void); |
| void (*clear_penirq)(void); |
| }; |
| |
| static inline int ak4183_xfer(struct ak4183 *tsc, u8 cmd) |
| { |
| s32 data; |
| u16 val; |
| |
| data = i2c_smbus_read_word_data(tsc->client, cmd); |
| if (data < 0) { |
| dev_err(&tsc->client->dev, "i2c io error: %d\n", data); |
| return data; |
| } |
| |
| /* The protocol and raw data format from i2c interface: |
| * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P |
| * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit]. |
| */ |
| val = swab16(data) >> 4; |
| |
| dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val); |
| |
| return val; |
| } |
| |
| static void ak4183_send_event(void *tsc) |
| { |
| struct ak4183 *ts = tsc; |
| u32 rt; |
| u32 x, y, z1, z2; |
| |
| x = ts->tc.x; |
| y = ts->tc.y; |
| z1 = ts->tc.z1; |
| z2 = ts->tc.z2; |
| |
| /* range filtering */ |
| if (x >= MAX_12BIT) |
| x = 0; |
| |
| if (likely(x && z1)) { |
| /* compute touch pressure resistance using equation #1 */ |
| rt = z2; |
| rt -= z1; |
| rt *= x; |
| rt *= ts->x_plate_ohms; |
| rt /= z1; |
| rt = (rt + 2047) >> 12; |
| } else |
| rt = 0; |
| |
| /* Sample found inconsistent by debouncing or pressure is beyond |
| * the maximum. Don't report it to user space, repeat at least |
| * once more the measurement |
| */ |
| if (rt > MAX_12BIT) { |
| dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt); |
| |
| return; |
| } |
| |
| /* NOTE: We can't rely on the pressure to determine the pen down |
| * state, even this controller has a pressure sensor. The pressure |
| * value can fluctuate for quite a while after lifting the pen and |
| * in some cases may not even settle at the expected value. |
| * |
| * The only safe way to check for the pen up condition is in the |
| * timer by reading the pen signal state (it's a GPIO _and_ IRQ). |
| */ |
| if (rt) { |
| struct input_dev *input = ts->input; |
| |
| if (!ts->pendown) { |
| dev_dbg(&ts->client->dev, "DOWN\n"); |
| |
| input_report_key(input, BTN_TOUCH, 1); |
| ts->pendown = 1; |
| } |
| |
| if (ts->fix.x_rescale) { |
| x = (x > ts->fix.x_min) ? (x - ts->fix.x_min) : 0; |
| x *= VAL_12BIT; |
| x /= (ts->fix.x_max - ts->fix.x_min); |
| if (x >= MAX_12BIT) |
| x = MAX_12BIT; |
| } |
| |
| if (ts->fix.y_rescale) { |
| y = (y > ts->fix.y_min) ? (y - ts->fix.y_min) : 0; |
| y *= VAL_12BIT; |
| y /= (ts->fix.y_max - ts->fix.y_min); |
| if (y >= MAX_12BIT) |
| y = MAX_12BIT; |
| } |
| |
| if (ts->fix.x_invert) |
| x = (MAX_12BIT - x); |
| |
| if (ts->fix.y_invert) |
| y = (MAX_12BIT - y); |
| |
| input_report_abs(input, ABS_X, x); |
| input_report_abs(input, ABS_Y, y); |
| input_report_abs(input, ABS_PRESSURE, rt); |
| |
| input_sync(input); |
| |
| dev_dbg(&ts->client->dev, |
| "point(%4d,%4d), pressure (%4u), real(%4d,%4d)\n", |
| x, y, rt, ts->tc.x, ts->tc.y); |
| } |
| } |
| |
| static int ak4183_read_values(struct ak4183 *tsc) |
| { |
| /* y- still on; turn on only y+ (and ADC) */ |
| tsc->tc.y = ak4183_xfer(tsc, READ_Y); |
| |
| /* turn y- off, x+ on, then leave in lowpower */ |
| tsc->tc.x = ak4183_xfer(tsc, READ_X); |
| |
| /* turn y+ off, x- on; we'll use formula #1 */ |
| tsc->tc.z1 = ak4183_xfer(tsc, READ_Z1); |
| tsc->tc.z2 = ak4183_xfer(tsc, READ_Z2); |
| |
| return 0; |
| } |
| |
| static enum hrtimer_restart ak4183_timer(struct hrtimer *handle) |
| { |
| struct ak4183 *ts = container_of(handle, struct ak4183, timer); |
| |
| queue_work(ts->workqueue, &ts->report_worker); |
| |
| return HRTIMER_NORESTART; |
| } |
| |
| static irqreturn_t ak4183_irq(int irq, void *handle) |
| { |
| struct ak4183 *ts = handle; |
| |
| if (likely(ts->get_pendown_state())) { |
| disable_irq_nosync(ts->irq); |
| hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY), |
| HRTIMER_MODE_REL); |
| } |
| |
| return IRQ_HANDLED; |
| } |
| |
| static void ak4183_report_worker(struct work_struct *work) |
| { |
| struct ak4183 *ts; |
| |
| ts = container_of(work, struct ak4183, report_worker); |
| |
| if (unlikely(!ts->get_pendown_state() && ts->pendown)) { |
| struct input_dev *input = ts->input; |
| |
| dev_dbg(&ts->client->dev, "UP\n"); |
| |
| input_report_key(input, BTN_TOUCH, 0); |
| input_report_abs(input, ABS_PRESSURE, 0); |
| input_sync(input); |
| |
| ts->pendown = 0; |
| |
| if (ts->clear_penirq) |
| ts->clear_penirq(); |
| enable_irq(ts->irq); |
| } else { |
| /* pen is still down, continue with the measurement */ |
| dev_dbg(&ts->client->dev, "pen is still down\n"); |
| |
| ak4183_read_values(ts); |
| ak4183_send_event(ts); |
| |
| hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD), |
| HRTIMER_MODE_REL); |
| } |
| } |
| |
| static int ak4183_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| struct ak4183 *ts; |
| struct ak4183_platform_data *pdata = pdata = client->dev.platform_data; |
| struct input_dev *input_dev; |
| int err; |
| |
| if (!pdata) { |
| dev_err(&client->dev, "platform data is required!\n"); |
| return -EINVAL; |
| } |
| |
| if (!i2c_check_functionality(client->adapter, |
| I2C_FUNC_SMBUS_READ_WORD_DATA)) |
| return -EIO; |
| |
| ts = kzalloc(sizeof(struct ak4183), GFP_KERNEL); |
| input_dev = input_allocate_device(); |
| if (!ts || !input_dev) { |
| err = -ENOMEM; |
| goto err_free_mem; |
| } |
| |
| ts->client = client; |
| i2c_set_clientdata(client, ts); |
| |
| ts->input = input_dev; |
| |
| hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
| ts->timer.function = ak4183_timer; |
| |
| spin_lock_init(&ts->lock); |
| |
| ts->model = pdata->model; |
| ts->x_plate_ohms = pdata->x_plate_ohms; |
| ts->fix = pdata->fix; |
| ts->get_pendown_state = pdata->get_pendown_state; |
| ts->clear_penirq = pdata->clear_penirq; |
| |
| pdata->init_platform_hw(); |
| |
| snprintf(ts->phys, sizeof(ts->phys), |
| "%s/input0", dev_name(&client->dev)); |
| |
| input_dev->name = "AK4183 Touchscreen"; |
| input_dev->phys = ts->phys; |
| input_dev->id.bustype = BUS_I2C; |
| |
| input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); |
| input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); |
| |
| input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0); |
| input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0); |
| input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0); |
| |
| ak4183_read_values(ts); |
| |
| ts->workqueue = create_singlethread_workqueue("ak4183"); |
| INIT_WORK(&ts->report_worker, ak4183_report_worker); |
| ts->irq = client->irq; |
| |
| err = request_irq(ts->irq, ak4183_irq, 0, |
| client->dev.driver->name, ts); |
| if (err < 0) { |
| dev_err(&client->dev, "irq %d busy?\n", ts->irq); |
| goto err_free_mem; |
| } |
| |
| err = input_register_device(input_dev); |
| if (err) |
| goto err_free_irq; |
| |
| dev_info(&client->dev, "registered with irq (%d)\n", ts->irq); |
| |
| return 0; |
| |
| err_free_irq: |
| free_irq(ts->irq, ts); |
| hrtimer_cancel(&ts->timer); |
| err_free_mem: |
| input_free_device(input_dev); |
| kfree(ts); |
| return err; |
| } |
| |
| static int ak4183_remove(struct i2c_client *client) |
| { |
| struct ak4183 *ts = i2c_get_clientdata(client); |
| struct ak4183_platform_data *pdata; |
| |
| pdata = client->dev.platform_data; |
| pdata->exit_platform_hw(); |
| |
| destroy_workqueue(ts->workqueue); |
| free_irq(ts->irq, ts); |
| hrtimer_cancel(&ts->timer); |
| input_unregister_device(ts->input); |
| kfree(ts); |
| |
| return 0; |
| } |
| |
| static struct i2c_device_id ak4183_idtable[] = { |
| { "ak4183", 0 }, |
| { } |
| }; |
| |
| MODULE_DEVICE_TABLE(i2c, ak4183_idtable); |
| |
| static struct i2c_driver ak4183_driver = { |
| .driver = { |
| .owner = THIS_MODULE, |
| .name = "ak4183" |
| }, |
| .id_table = ak4183_idtable, |
| .probe = ak4183_probe, |
| .remove = ak4183_remove, |
| }; |
| |
| static int __init ak4183_init(void) |
| { |
| return i2c_add_driver(&ak4183_driver); |
| } |
| |
| static void __exit ak4183_exit(void) |
| { |
| i2c_del_driver(&ak4183_driver); |
| } |
| |
| module_init(ak4183_init); |
| module_exit(ak4183_exit); |
| |
| MODULE_AUTHOR("Zhenwu Xue <zwxue@ambarella.com>"); |
| MODULE_DESCRIPTION("AK4183 TouchScreen Driver"); |
| MODULE_LICENSE("GPL"); |