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455 lines
11 KiB
455 lines
11 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* drivers/input/touchscreen/tsc2007.c |
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* |
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* Copyright (c) 2008 MtekVision Co., Ltd. |
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* Kwangwoo Lee <[email protected]> |
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* |
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* Using code from: |
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* - ads7846.c |
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* Copyright (c) 2005 David Brownell |
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* Copyright (c) 2006 Nokia Corporation |
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* - corgi_ts.c |
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* Copyright (C) 2004-2005 Richard Purdie |
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* - omap_ts.[hc], ads7846.h, ts_osk.c |
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* Copyright (C) 2002 MontaVista Software |
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* Copyright (C) 2004 Texas Instruments |
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* Copyright (C) 2005 Dirk Behme |
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*/ |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/input.h> |
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#include <linux/interrupt.h> |
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#include <linux/i2c.h> |
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#include <linux/of_device.h> |
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#include <linux/of_gpio.h> |
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#include <linux/platform_data/tsc2007.h> |
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#include "tsc2007.h" |
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int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd) |
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{ |
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s32 data; |
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u16 val; |
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data = i2c_smbus_read_word_data(tsc->client, cmd); |
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if (data < 0) { |
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dev_err(&tsc->client->dev, "i2c io error: %d\n", data); |
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return data; |
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} |
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/* The protocol and raw data format from i2c interface: |
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* S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P |
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* Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit]. |
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*/ |
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val = swab16(data) >> 4; |
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dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val); |
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return val; |
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} |
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static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc) |
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{ |
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/* y- still on; turn on only y+ (and ADC) */ |
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tc->y = tsc2007_xfer(tsc, READ_Y); |
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/* turn y- off, x+ on, then leave in lowpower */ |
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tc->x = tsc2007_xfer(tsc, READ_X); |
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/* turn y+ off, x- on; we'll use formula #1 */ |
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tc->z1 = tsc2007_xfer(tsc, READ_Z1); |
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tc->z2 = tsc2007_xfer(tsc, READ_Z2); |
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/* Prepare for next touch reading - power down ADC, enable PENIRQ */ |
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tsc2007_xfer(tsc, PWRDOWN); |
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} |
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u32 tsc2007_calculate_resistance(struct tsc2007 *tsc, struct ts_event *tc) |
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{ |
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u32 rt = 0; |
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/* range filtering */ |
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if (tc->x == MAX_12BIT) |
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tc->x = 0; |
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if (likely(tc->x && tc->z1)) { |
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/* compute touch resistance using equation #1 */ |
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rt = tc->z2 - tc->z1; |
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rt *= tc->x; |
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rt *= tsc->x_plate_ohms; |
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rt /= tc->z1; |
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rt = (rt + 2047) >> 12; |
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} |
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return rt; |
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} |
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bool tsc2007_is_pen_down(struct tsc2007 *ts) |
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{ |
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/* |
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* NOTE: We can't rely on the pressure to determine the pen down |
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* state, even though this controller has a pressure sensor. |
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* The pressure value can fluctuate for quite a while after |
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* lifting the pen and in some cases may not even settle at the |
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* expected value. |
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* |
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* The only safe way to check for the pen up condition is in the |
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* work function by reading the pen signal state (it's a GPIO |
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* and IRQ). Unfortunately such callback is not always available, |
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* in that case we assume that the pen is down and expect caller |
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* to fall back on the pressure reading. |
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*/ |
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if (!ts->get_pendown_state) |
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return true; |
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return ts->get_pendown_state(&ts->client->dev); |
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} |
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static irqreturn_t tsc2007_soft_irq(int irq, void *handle) |
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{ |
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struct tsc2007 *ts = handle; |
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struct input_dev *input = ts->input; |
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struct ts_event tc; |
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u32 rt; |
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while (!ts->stopped && tsc2007_is_pen_down(ts)) { |
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/* pen is down, continue with the measurement */ |
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mutex_lock(&ts->mlock); |
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tsc2007_read_values(ts, &tc); |
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mutex_unlock(&ts->mlock); |
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rt = tsc2007_calculate_resistance(ts, &tc); |
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if (!rt && !ts->get_pendown_state) { |
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/* |
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* If pressure reported is 0 and we don't have |
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* callback to check pendown state, we have to |
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* assume that pen was lifted up. |
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*/ |
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break; |
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} |
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if (rt <= ts->max_rt) { |
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dev_dbg(&ts->client->dev, |
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"DOWN point(%4d,%4d), resistance (%4u)\n", |
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tc.x, tc.y, rt); |
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rt = ts->max_rt - rt; |
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input_report_key(input, BTN_TOUCH, 1); |
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input_report_abs(input, ABS_X, tc.x); |
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input_report_abs(input, ABS_Y, tc.y); |
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input_report_abs(input, ABS_PRESSURE, rt); |
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input_sync(input); |
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} else { |
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/* |
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* Sample found inconsistent by debouncing or pressure is |
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* beyond the maximum. Don't report it to user space, |
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* repeat at least once more the measurement. |
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*/ |
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dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt); |
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} |
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wait_event_timeout(ts->wait, ts->stopped, ts->poll_period); |
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} |
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dev_dbg(&ts->client->dev, "UP\n"); |
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input_report_key(input, BTN_TOUCH, 0); |
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input_report_abs(input, ABS_PRESSURE, 0); |
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input_sync(input); |
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if (ts->clear_penirq) |
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ts->clear_penirq(); |
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return IRQ_HANDLED; |
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} |
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static irqreturn_t tsc2007_hard_irq(int irq, void *handle) |
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{ |
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struct tsc2007 *ts = handle; |
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if (tsc2007_is_pen_down(ts)) |
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return IRQ_WAKE_THREAD; |
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if (ts->clear_penirq) |
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ts->clear_penirq(); |
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return IRQ_HANDLED; |
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} |
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static void tsc2007_stop(struct tsc2007 *ts) |
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{ |
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ts->stopped = true; |
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mb(); |
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wake_up(&ts->wait); |
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disable_irq(ts->irq); |
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} |
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static int tsc2007_open(struct input_dev *input_dev) |
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{ |
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struct tsc2007 *ts = input_get_drvdata(input_dev); |
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int err; |
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ts->stopped = false; |
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mb(); |
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enable_irq(ts->irq); |
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/* Prepare for touch readings - power down ADC and enable PENIRQ */ |
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err = tsc2007_xfer(ts, PWRDOWN); |
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if (err < 0) { |
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tsc2007_stop(ts); |
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return err; |
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} |
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return 0; |
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} |
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static void tsc2007_close(struct input_dev *input_dev) |
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{ |
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struct tsc2007 *ts = input_get_drvdata(input_dev); |
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tsc2007_stop(ts); |
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} |
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#ifdef CONFIG_OF |
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static int tsc2007_get_pendown_state_gpio(struct device *dev) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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struct tsc2007 *ts = i2c_get_clientdata(client); |
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return !gpio_get_value(ts->gpio); |
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} |
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static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts) |
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{ |
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struct device_node *np = client->dev.of_node; |
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u32 val32; |
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u64 val64; |
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if (!np) { |
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dev_err(&client->dev, "missing device tree data\n"); |
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return -EINVAL; |
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} |
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if (!of_property_read_u32(np, "ti,max-rt", &val32)) |
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ts->max_rt = val32; |
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else |
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ts->max_rt = MAX_12BIT; |
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if (!of_property_read_u32(np, "ti,fuzzx", &val32)) |
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ts->fuzzx = val32; |
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if (!of_property_read_u32(np, "ti,fuzzy", &val32)) |
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ts->fuzzy = val32; |
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if (!of_property_read_u32(np, "ti,fuzzz", &val32)) |
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ts->fuzzz = val32; |
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if (!of_property_read_u64(np, "ti,poll-period", &val64)) |
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ts->poll_period = msecs_to_jiffies(val64); |
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else |
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ts->poll_period = msecs_to_jiffies(1); |
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if (!of_property_read_u32(np, "ti,x-plate-ohms", &val32)) { |
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ts->x_plate_ohms = val32; |
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} else { |
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dev_err(&client->dev, "missing ti,x-plate-ohms devicetree property."); |
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return -EINVAL; |
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} |
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ts->gpio = of_get_gpio(np, 0); |
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if (gpio_is_valid(ts->gpio)) |
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ts->get_pendown_state = tsc2007_get_pendown_state_gpio; |
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else |
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dev_warn(&client->dev, |
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"GPIO not specified in DT (of_get_gpio returned %d)\n", |
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ts->gpio); |
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return 0; |
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} |
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#else |
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static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts) |
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{ |
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dev_err(&client->dev, "platform data is required!\n"); |
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return -EINVAL; |
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} |
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#endif |
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static int tsc2007_probe_pdev(struct i2c_client *client, struct tsc2007 *ts, |
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const struct tsc2007_platform_data *pdata, |
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const struct i2c_device_id *id) |
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{ |
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ts->model = pdata->model; |
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ts->x_plate_ohms = pdata->x_plate_ohms; |
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ts->max_rt = pdata->max_rt ? : MAX_12BIT; |
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ts->poll_period = msecs_to_jiffies(pdata->poll_period ? : 1); |
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ts->get_pendown_state = pdata->get_pendown_state; |
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ts->clear_penirq = pdata->clear_penirq; |
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ts->fuzzx = pdata->fuzzx; |
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ts->fuzzy = pdata->fuzzy; |
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ts->fuzzz = pdata->fuzzz; |
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if (pdata->x_plate_ohms == 0) { |
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dev_err(&client->dev, "x_plate_ohms is not set up in platform data"); |
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return -EINVAL; |
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} |
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return 0; |
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} |
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static void tsc2007_call_exit_platform_hw(void *data) |
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{ |
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struct device *dev = data; |
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const struct tsc2007_platform_data *pdata = dev_get_platdata(dev); |
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pdata->exit_platform_hw(); |
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} |
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static int tsc2007_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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const struct tsc2007_platform_data *pdata = |
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dev_get_platdata(&client->dev); |
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struct tsc2007 *ts; |
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struct input_dev *input_dev; |
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int err; |
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if (!i2c_check_functionality(client->adapter, |
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I2C_FUNC_SMBUS_READ_WORD_DATA)) |
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return -EIO; |
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ts = devm_kzalloc(&client->dev, sizeof(struct tsc2007), GFP_KERNEL); |
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if (!ts) |
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return -ENOMEM; |
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if (pdata) |
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err = tsc2007_probe_pdev(client, ts, pdata, id); |
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else |
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err = tsc2007_probe_dt(client, ts); |
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if (err) |
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return err; |
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input_dev = devm_input_allocate_device(&client->dev); |
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if (!input_dev) |
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return -ENOMEM; |
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i2c_set_clientdata(client, ts); |
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ts->client = client; |
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ts->irq = client->irq; |
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ts->input = input_dev; |
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init_waitqueue_head(&ts->wait); |
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mutex_init(&ts->mlock); |
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snprintf(ts->phys, sizeof(ts->phys), |
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"%s/input0", dev_name(&client->dev)); |
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input_dev->name = "TSC2007 Touchscreen"; |
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input_dev->phys = ts->phys; |
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input_dev->id.bustype = BUS_I2C; |
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input_dev->open = tsc2007_open; |
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input_dev->close = tsc2007_close; |
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input_set_drvdata(input_dev, ts); |
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input_set_capability(input_dev, EV_KEY, BTN_TOUCH); |
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input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, ts->fuzzx, 0); |
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input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, ts->fuzzy, 0); |
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input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, |
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ts->fuzzz, 0); |
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if (pdata) { |
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if (pdata->exit_platform_hw) { |
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err = devm_add_action(&client->dev, |
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tsc2007_call_exit_platform_hw, |
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&client->dev); |
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if (err) { |
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dev_err(&client->dev, |
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"Failed to register exit_platform_hw action, %d\n", |
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err); |
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return err; |
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} |
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} |
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if (pdata->init_platform_hw) |
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pdata->init_platform_hw(); |
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} |
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err = devm_request_threaded_irq(&client->dev, ts->irq, |
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tsc2007_hard_irq, tsc2007_soft_irq, |
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IRQF_ONESHOT, |
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client->dev.driver->name, ts); |
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if (err) { |
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dev_err(&client->dev, "Failed to request irq %d: %d\n", |
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ts->irq, err); |
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return err; |
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} |
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tsc2007_stop(ts); |
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/* power down the chip (TSC2007_SETUP does not ACK on I2C) */ |
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err = tsc2007_xfer(ts, PWRDOWN); |
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if (err < 0) { |
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dev_err(&client->dev, |
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"Failed to setup chip: %d\n", err); |
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return err; /* chip does not respond */ |
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} |
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err = input_register_device(input_dev); |
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if (err) { |
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dev_err(&client->dev, |
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"Failed to register input device: %d\n", err); |
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return err; |
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} |
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err = tsc2007_iio_configure(ts); |
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if (err) { |
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dev_err(&client->dev, |
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"Failed to register with IIO: %d\n", err); |
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return err; |
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} |
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return 0; |
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} |
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static const struct i2c_device_id tsc2007_idtable[] = { |
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{ "tsc2007", 0 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, tsc2007_idtable); |
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#ifdef CONFIG_OF |
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static const struct of_device_id tsc2007_of_match[] = { |
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{ .compatible = "ti,tsc2007" }, |
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{ /* sentinel */ } |
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}; |
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MODULE_DEVICE_TABLE(of, tsc2007_of_match); |
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#endif |
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static struct i2c_driver tsc2007_driver = { |
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.driver = { |
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.name = "tsc2007", |
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.of_match_table = of_match_ptr(tsc2007_of_match), |
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}, |
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.id_table = tsc2007_idtable, |
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.probe = tsc2007_probe, |
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}; |
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module_i2c_driver(tsc2007_driver); |
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MODULE_AUTHOR("Kwangwoo Lee <[email protected]>"); |
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MODULE_DESCRIPTION("TSC2007 TouchScreen Driver"); |
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MODULE_LICENSE("GPL");
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