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629 lines
15 KiB
629 lines
15 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
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* TSC2004/TSC2005 touchscreen driver core |
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* |
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* Copyright (C) 2006-2010 Nokia Corporation |
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* Copyright (C) 2015 QWERTY Embedded Design |
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* Copyright (C) 2015 EMAC Inc. |
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* |
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* Author: Lauri Leukkunen <[email protected]> |
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* based on TSC2301 driver by Klaus K. Pedersen <[email protected]> |
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*/ |
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|
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/input.h> |
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#include <linux/input/touchscreen.h> |
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#include <linux/interrupt.h> |
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#include <linux/delay.h> |
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#include <linux/pm.h> |
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#include <linux/of.h> |
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#include <linux/regulator/consumer.h> |
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#include <linux/regmap.h> |
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#include <linux/gpio/consumer.h> |
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#include "tsc200x-core.h" |
|
|
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/* |
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* The touchscreen interface operates as follows: |
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* |
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* 1) Pen is pressed against the touchscreen. |
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* 2) TSC200X performs AD conversion. |
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* 3) After the conversion is done TSC200X drives DAV line down. |
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* 4) GPIO IRQ is received and tsc200x_irq_thread() is scheduled. |
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* 5) tsc200x_irq_thread() queues up a transfer to fetch the x, y, z1, z2 |
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* values. |
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* 6) tsc200x_irq_thread() reports coordinates to input layer and sets up |
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* tsc200x_penup_timer() to be called after TSC200X_PENUP_TIME_MS (40ms). |
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* 7) When the penup timer expires, there have not been touch or DAV interrupts |
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* during the last 40ms which means the pen has been lifted. |
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* |
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* ESD recovery via a hardware reset is done if the TSC200X doesn't respond |
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* after a configurable period (in ms) of activity. If esd_timeout is 0, the |
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* watchdog is disabled. |
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*/ |
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|
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static const struct regmap_range tsc200x_writable_ranges[] = { |
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regmap_reg_range(TSC200X_REG_AUX_HIGH, TSC200X_REG_CFR2), |
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}; |
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|
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static const struct regmap_access_table tsc200x_writable_table = { |
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.yes_ranges = tsc200x_writable_ranges, |
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.n_yes_ranges = ARRAY_SIZE(tsc200x_writable_ranges), |
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}; |
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|
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const struct regmap_config tsc200x_regmap_config = { |
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.reg_bits = 8, |
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.val_bits = 16, |
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.reg_stride = 0x08, |
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.max_register = 0x78, |
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.read_flag_mask = TSC200X_REG_READ, |
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.write_flag_mask = TSC200X_REG_PND0, |
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.wr_table = &tsc200x_writable_table, |
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.use_single_read = true, |
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.use_single_write = true, |
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}; |
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EXPORT_SYMBOL_GPL(tsc200x_regmap_config); |
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|
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struct tsc200x_data { |
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u16 x; |
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u16 y; |
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u16 z1; |
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u16 z2; |
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} __packed; |
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#define TSC200X_DATA_REGS 4 |
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|
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struct tsc200x { |
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struct device *dev; |
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struct regmap *regmap; |
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__u16 bustype; |
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|
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struct input_dev *idev; |
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char phys[32]; |
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|
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struct mutex mutex; |
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|
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/* raw copy of previous x,y,z */ |
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int in_x; |
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int in_y; |
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int in_z1; |
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int in_z2; |
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|
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spinlock_t lock; |
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struct timer_list penup_timer; |
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|
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unsigned int esd_timeout; |
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struct delayed_work esd_work; |
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unsigned long last_valid_interrupt; |
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|
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unsigned int x_plate_ohm; |
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|
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bool opened; |
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bool suspended; |
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|
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bool pen_down; |
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|
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struct regulator *vio; |
|
|
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struct gpio_desc *reset_gpio; |
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int (*tsc200x_cmd)(struct device *dev, u8 cmd); |
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int irq; |
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}; |
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|
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static void tsc200x_update_pen_state(struct tsc200x *ts, |
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int x, int y, int pressure) |
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{ |
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if (pressure) { |
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input_report_abs(ts->idev, ABS_X, x); |
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input_report_abs(ts->idev, ABS_Y, y); |
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input_report_abs(ts->idev, ABS_PRESSURE, pressure); |
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if (!ts->pen_down) { |
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input_report_key(ts->idev, BTN_TOUCH, !!pressure); |
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ts->pen_down = true; |
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} |
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} else { |
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input_report_abs(ts->idev, ABS_PRESSURE, 0); |
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if (ts->pen_down) { |
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input_report_key(ts->idev, BTN_TOUCH, 0); |
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ts->pen_down = false; |
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} |
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} |
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input_sync(ts->idev); |
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dev_dbg(ts->dev, "point(%4d,%4d), pressure (%4d)\n", x, y, |
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pressure); |
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} |
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|
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static irqreturn_t tsc200x_irq_thread(int irq, void *_ts) |
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{ |
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struct tsc200x *ts = _ts; |
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unsigned long flags; |
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unsigned int pressure; |
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struct tsc200x_data tsdata; |
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int error; |
|
|
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/* read the coordinates */ |
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error = regmap_bulk_read(ts->regmap, TSC200X_REG_X, &tsdata, |
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TSC200X_DATA_REGS); |
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if (unlikely(error)) |
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goto out; |
|
|
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/* validate position */ |
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if (unlikely(tsdata.x > MAX_12BIT || tsdata.y > MAX_12BIT)) |
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goto out; |
|
|
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/* Skip reading if the pressure components are out of range */ |
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if (unlikely(tsdata.z1 == 0 || tsdata.z2 > MAX_12BIT)) |
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goto out; |
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if (unlikely(tsdata.z1 >= tsdata.z2)) |
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goto out; |
|
|
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/* |
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* Skip point if this is a pen down with the exact same values as |
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* the value before pen-up - that implies SPI fed us stale data |
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*/ |
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if (!ts->pen_down && |
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ts->in_x == tsdata.x && ts->in_y == tsdata.y && |
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ts->in_z1 == tsdata.z1 && ts->in_z2 == tsdata.z2) { |
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goto out; |
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} |
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|
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/* |
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* At this point we are happy we have a valid and useful reading. |
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* Remember it for later comparisons. We may now begin downsampling. |
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*/ |
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ts->in_x = tsdata.x; |
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ts->in_y = tsdata.y; |
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ts->in_z1 = tsdata.z1; |
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ts->in_z2 = tsdata.z2; |
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|
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/* Compute touch pressure resistance using equation #1 */ |
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pressure = tsdata.x * (tsdata.z2 - tsdata.z1) / tsdata.z1; |
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pressure = pressure * ts->x_plate_ohm / 4096; |
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if (unlikely(pressure > MAX_12BIT)) |
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goto out; |
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|
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spin_lock_irqsave(&ts->lock, flags); |
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|
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tsc200x_update_pen_state(ts, tsdata.x, tsdata.y, pressure); |
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mod_timer(&ts->penup_timer, |
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jiffies + msecs_to_jiffies(TSC200X_PENUP_TIME_MS)); |
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|
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spin_unlock_irqrestore(&ts->lock, flags); |
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|
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ts->last_valid_interrupt = jiffies; |
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out: |
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return IRQ_HANDLED; |
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} |
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|
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static void tsc200x_penup_timer(struct timer_list *t) |
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{ |
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struct tsc200x *ts = from_timer(ts, t, penup_timer); |
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unsigned long flags; |
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|
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spin_lock_irqsave(&ts->lock, flags); |
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tsc200x_update_pen_state(ts, 0, 0, 0); |
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spin_unlock_irqrestore(&ts->lock, flags); |
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} |
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|
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static void tsc200x_start_scan(struct tsc200x *ts) |
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{ |
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regmap_write(ts->regmap, TSC200X_REG_CFR0, TSC200X_CFR0_INITVALUE); |
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regmap_write(ts->regmap, TSC200X_REG_CFR1, TSC200X_CFR1_INITVALUE); |
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regmap_write(ts->regmap, TSC200X_REG_CFR2, TSC200X_CFR2_INITVALUE); |
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ts->tsc200x_cmd(ts->dev, TSC200X_CMD_NORMAL); |
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} |
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|
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static void tsc200x_stop_scan(struct tsc200x *ts) |
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{ |
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ts->tsc200x_cmd(ts->dev, TSC200X_CMD_STOP); |
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} |
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|
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static void tsc200x_reset(struct tsc200x *ts) |
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{ |
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if (ts->reset_gpio) { |
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gpiod_set_value_cansleep(ts->reset_gpio, 1); |
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usleep_range(100, 500); /* only 10us required */ |
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gpiod_set_value_cansleep(ts->reset_gpio, 0); |
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} |
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} |
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|
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/* must be called with ts->mutex held */ |
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static void __tsc200x_disable(struct tsc200x *ts) |
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{ |
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tsc200x_stop_scan(ts); |
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|
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disable_irq(ts->irq); |
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del_timer_sync(&ts->penup_timer); |
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|
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cancel_delayed_work_sync(&ts->esd_work); |
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|
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enable_irq(ts->irq); |
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} |
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|
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/* must be called with ts->mutex held */ |
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static void __tsc200x_enable(struct tsc200x *ts) |
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{ |
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tsc200x_start_scan(ts); |
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|
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if (ts->esd_timeout && ts->reset_gpio) { |
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ts->last_valid_interrupt = jiffies; |
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schedule_delayed_work(&ts->esd_work, |
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round_jiffies_relative( |
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msecs_to_jiffies(ts->esd_timeout))); |
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} |
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} |
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|
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static ssize_t tsc200x_selftest_show(struct device *dev, |
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struct device_attribute *attr, |
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char *buf) |
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{ |
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struct tsc200x *ts = dev_get_drvdata(dev); |
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unsigned int temp_high; |
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unsigned int temp_high_orig; |
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unsigned int temp_high_test; |
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bool success = true; |
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int error; |
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|
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mutex_lock(&ts->mutex); |
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|
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/* |
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* Test TSC200X communications via temp high register. |
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*/ |
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__tsc200x_disable(ts); |
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|
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error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high_orig); |
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if (error) { |
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dev_warn(dev, "selftest failed: read error %d\n", error); |
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success = false; |
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goto out; |
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} |
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|
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temp_high_test = (temp_high_orig - 1) & MAX_12BIT; |
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|
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error = regmap_write(ts->regmap, TSC200X_REG_TEMP_HIGH, temp_high_test); |
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if (error) { |
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dev_warn(dev, "selftest failed: write error %d\n", error); |
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success = false; |
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goto out; |
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} |
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|
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error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high); |
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if (error) { |
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dev_warn(dev, "selftest failed: read error %d after write\n", |
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error); |
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success = false; |
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goto out; |
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} |
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|
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if (temp_high != temp_high_test) { |
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dev_warn(dev, "selftest failed: %d != %d\n", |
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temp_high, temp_high_test); |
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success = false; |
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} |
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|
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/* hardware reset */ |
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tsc200x_reset(ts); |
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|
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if (!success) |
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goto out; |
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|
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/* test that the reset really happened */ |
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error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high); |
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if (error) { |
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dev_warn(dev, "selftest failed: read error %d after reset\n", |
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error); |
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success = false; |
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goto out; |
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} |
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|
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if (temp_high != temp_high_orig) { |
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dev_warn(dev, "selftest failed after reset: %d != %d\n", |
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temp_high, temp_high_orig); |
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success = false; |
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} |
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|
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out: |
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__tsc200x_enable(ts); |
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mutex_unlock(&ts->mutex); |
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|
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return sprintf(buf, "%d\n", success); |
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} |
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|
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static DEVICE_ATTR(selftest, S_IRUGO, tsc200x_selftest_show, NULL); |
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|
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static struct attribute *tsc200x_attrs[] = { |
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&dev_attr_selftest.attr, |
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NULL |
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}; |
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|
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static umode_t tsc200x_attr_is_visible(struct kobject *kobj, |
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struct attribute *attr, int n) |
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{ |
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struct device *dev = container_of(kobj, struct device, kobj); |
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struct tsc200x *ts = dev_get_drvdata(dev); |
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umode_t mode = attr->mode; |
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|
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if (attr == &dev_attr_selftest.attr) { |
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if (!ts->reset_gpio) |
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mode = 0; |
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} |
|
|
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return mode; |
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} |
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|
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static const struct attribute_group tsc200x_attr_group = { |
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.is_visible = tsc200x_attr_is_visible, |
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.attrs = tsc200x_attrs, |
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}; |
|
|
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static void tsc200x_esd_work(struct work_struct *work) |
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{ |
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struct tsc200x *ts = container_of(work, struct tsc200x, esd_work.work); |
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int error; |
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unsigned int r; |
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|
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if (!mutex_trylock(&ts->mutex)) { |
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/* |
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* If the mutex is taken, it means that disable or enable is in |
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* progress. In that case just reschedule the work. If the work |
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* is not needed, it will be canceled by disable. |
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*/ |
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goto reschedule; |
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} |
|
|
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if (time_is_after_jiffies(ts->last_valid_interrupt + |
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msecs_to_jiffies(ts->esd_timeout))) |
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goto out; |
|
|
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/* We should be able to read register without disabling interrupts. */ |
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error = regmap_read(ts->regmap, TSC200X_REG_CFR0, &r); |
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if (!error && |
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!((r ^ TSC200X_CFR0_INITVALUE) & TSC200X_CFR0_RW_MASK)) { |
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goto out; |
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} |
|
|
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/* |
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* If we could not read our known value from configuration register 0 |
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* then we should reset the controller as if from power-up and start |
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* scanning again. |
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*/ |
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dev_info(ts->dev, "TSC200X not responding - resetting\n"); |
|
|
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disable_irq(ts->irq); |
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del_timer_sync(&ts->penup_timer); |
|
|
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tsc200x_update_pen_state(ts, 0, 0, 0); |
|
|
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tsc200x_reset(ts); |
|
|
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enable_irq(ts->irq); |
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tsc200x_start_scan(ts); |
|
|
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out: |
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mutex_unlock(&ts->mutex); |
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reschedule: |
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/* re-arm the watchdog */ |
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schedule_delayed_work(&ts->esd_work, |
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round_jiffies_relative( |
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msecs_to_jiffies(ts->esd_timeout))); |
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} |
|
|
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static int tsc200x_open(struct input_dev *input) |
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{ |
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struct tsc200x *ts = input_get_drvdata(input); |
|
|
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mutex_lock(&ts->mutex); |
|
|
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if (!ts->suspended) |
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__tsc200x_enable(ts); |
|
|
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ts->opened = true; |
|
|
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mutex_unlock(&ts->mutex); |
|
|
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return 0; |
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} |
|
|
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static void tsc200x_close(struct input_dev *input) |
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{ |
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struct tsc200x *ts = input_get_drvdata(input); |
|
|
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mutex_lock(&ts->mutex); |
|
|
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if (!ts->suspended) |
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__tsc200x_disable(ts); |
|
|
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ts->opened = false; |
|
|
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mutex_unlock(&ts->mutex); |
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} |
|
|
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int tsc200x_probe(struct device *dev, int irq, const struct input_id *tsc_id, |
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struct regmap *regmap, |
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int (*tsc200x_cmd)(struct device *dev, u8 cmd)) |
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{ |
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struct tsc200x *ts; |
|
struct input_dev *input_dev; |
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u32 x_plate_ohm; |
|
u32 esd_timeout; |
|
int error; |
|
|
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if (irq <= 0) { |
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dev_err(dev, "no irq\n"); |
|
return -ENODEV; |
|
} |
|
|
|
if (IS_ERR(regmap)) |
|
return PTR_ERR(regmap); |
|
|
|
if (!tsc200x_cmd) { |
|
dev_err(dev, "no cmd function\n"); |
|
return -ENODEV; |
|
} |
|
|
|
ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL); |
|
if (!ts) |
|
return -ENOMEM; |
|
|
|
input_dev = devm_input_allocate_device(dev); |
|
if (!input_dev) |
|
return -ENOMEM; |
|
|
|
ts->irq = irq; |
|
ts->dev = dev; |
|
ts->idev = input_dev; |
|
ts->regmap = regmap; |
|
ts->tsc200x_cmd = tsc200x_cmd; |
|
|
|
error = device_property_read_u32(dev, "ti,x-plate-ohms", &x_plate_ohm); |
|
ts->x_plate_ohm = error ? TSC200X_DEF_RESISTOR : x_plate_ohm; |
|
|
|
error = device_property_read_u32(dev, "ti,esd-recovery-timeout-ms", |
|
&esd_timeout); |
|
ts->esd_timeout = error ? 0 : esd_timeout; |
|
|
|
ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); |
|
if (IS_ERR(ts->reset_gpio)) { |
|
error = PTR_ERR(ts->reset_gpio); |
|
dev_err(dev, "error acquiring reset gpio: %d\n", error); |
|
return error; |
|
} |
|
|
|
ts->vio = devm_regulator_get(dev, "vio"); |
|
if (IS_ERR(ts->vio)) { |
|
error = PTR_ERR(ts->vio); |
|
dev_err(dev, "error acquiring vio regulator: %d", error); |
|
return error; |
|
} |
|
|
|
mutex_init(&ts->mutex); |
|
|
|
spin_lock_init(&ts->lock); |
|
timer_setup(&ts->penup_timer, tsc200x_penup_timer, 0); |
|
|
|
INIT_DELAYED_WORK(&ts->esd_work, tsc200x_esd_work); |
|
|
|
snprintf(ts->phys, sizeof(ts->phys), |
|
"%s/input-ts", dev_name(dev)); |
|
|
|
if (tsc_id->product == 2004) { |
|
input_dev->name = "TSC200X touchscreen"; |
|
} else { |
|
input_dev->name = devm_kasprintf(dev, GFP_KERNEL, |
|
"TSC%04d touchscreen", |
|
tsc_id->product); |
|
if (!input_dev->name) |
|
return -ENOMEM; |
|
} |
|
|
|
input_dev->phys = ts->phys; |
|
input_dev->id = *tsc_id; |
|
|
|
input_dev->open = tsc200x_open; |
|
input_dev->close = tsc200x_close; |
|
|
|
input_set_drvdata(input_dev, ts); |
|
|
|
__set_bit(INPUT_PROP_DIRECT, input_dev->propbit); |
|
input_set_capability(input_dev, EV_KEY, BTN_TOUCH); |
|
|
|
input_set_abs_params(input_dev, ABS_X, |
|
0, MAX_12BIT, TSC200X_DEF_X_FUZZ, 0); |
|
input_set_abs_params(input_dev, ABS_Y, |
|
0, MAX_12BIT, TSC200X_DEF_Y_FUZZ, 0); |
|
input_set_abs_params(input_dev, ABS_PRESSURE, |
|
0, MAX_12BIT, TSC200X_DEF_P_FUZZ, 0); |
|
|
|
touchscreen_parse_properties(input_dev, false, NULL); |
|
|
|
/* Ensure the touchscreen is off */ |
|
tsc200x_stop_scan(ts); |
|
|
|
error = devm_request_threaded_irq(dev, irq, NULL, |
|
tsc200x_irq_thread, |
|
IRQF_TRIGGER_RISING | IRQF_ONESHOT, |
|
"tsc200x", ts); |
|
if (error) { |
|
dev_err(dev, "Failed to request irq, err: %d\n", error); |
|
return error; |
|
} |
|
|
|
error = regulator_enable(ts->vio); |
|
if (error) |
|
return error; |
|
|
|
dev_set_drvdata(dev, ts); |
|
error = sysfs_create_group(&dev->kobj, &tsc200x_attr_group); |
|
if (error) { |
|
dev_err(dev, |
|
"Failed to create sysfs attributes, err: %d\n", error); |
|
goto disable_regulator; |
|
} |
|
|
|
error = input_register_device(ts->idev); |
|
if (error) { |
|
dev_err(dev, |
|
"Failed to register input device, err: %d\n", error); |
|
goto err_remove_sysfs; |
|
} |
|
|
|
irq_set_irq_wake(irq, 1); |
|
return 0; |
|
|
|
err_remove_sysfs: |
|
sysfs_remove_group(&dev->kobj, &tsc200x_attr_group); |
|
disable_regulator: |
|
regulator_disable(ts->vio); |
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(tsc200x_probe); |
|
|
|
int tsc200x_remove(struct device *dev) |
|
{ |
|
struct tsc200x *ts = dev_get_drvdata(dev); |
|
|
|
sysfs_remove_group(&dev->kobj, &tsc200x_attr_group); |
|
|
|
regulator_disable(ts->vio); |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(tsc200x_remove); |
|
|
|
static int __maybe_unused tsc200x_suspend(struct device *dev) |
|
{ |
|
struct tsc200x *ts = dev_get_drvdata(dev); |
|
|
|
mutex_lock(&ts->mutex); |
|
|
|
if (!ts->suspended && ts->opened) |
|
__tsc200x_disable(ts); |
|
|
|
ts->suspended = true; |
|
|
|
mutex_unlock(&ts->mutex); |
|
|
|
return 0; |
|
} |
|
|
|
static int __maybe_unused tsc200x_resume(struct device *dev) |
|
{ |
|
struct tsc200x *ts = dev_get_drvdata(dev); |
|
|
|
mutex_lock(&ts->mutex); |
|
|
|
if (ts->suspended && ts->opened) |
|
__tsc200x_enable(ts); |
|
|
|
ts->suspended = false; |
|
|
|
mutex_unlock(&ts->mutex); |
|
|
|
return 0; |
|
} |
|
|
|
SIMPLE_DEV_PM_OPS(tsc200x_pm_ops, tsc200x_suspend, tsc200x_resume); |
|
EXPORT_SYMBOL_GPL(tsc200x_pm_ops); |
|
|
|
MODULE_AUTHOR("Lauri Leukkunen <[email protected]>"); |
|
MODULE_DESCRIPTION("TSC200x Touchscreen Driver Core"); |
|
MODULE_LICENSE("GPL");
|
|
|