cregit-Linux how code gets into the kernel

Release 4.11 drivers/input/touchscreen/zforce_ts.c

/*
 * Copyright (C) 2012-2013 MundoReader S.L.
 * Author: Heiko Stuebner <heiko@sntech.de>
 *
 * based in parts on Nook zforce driver
 *
 * Copyright (C) 2010 Barnes & Noble, Inc.
 * Author: Pieter Truter<ptruter@intrinsyc.com>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#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/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/device.h>
#include <linux/sysfs.h>
#include <linux/input/mt.h>
#include <linux/platform_data/zforce_ts.h>
#include <linux/regulator/consumer.h>
#include <linux/of.h>


#define WAIT_TIMEOUT		msecs_to_jiffies(1000)


#define FRAME_START		0xee

#define FRAME_MAXSIZE		257

/* Offsets of the different parts of the payload the controller sends */

#define PAYLOAD_HEADER		0

#define PAYLOAD_LENGTH		1

#define PAYLOAD_BODY		2

/* Response offsets */

#define RESPONSE_ID		0

#define RESPONSE_DATA		1

/* Commands */

#define COMMAND_DEACTIVATE	0x00

#define COMMAND_INITIALIZE	0x01

#define COMMAND_RESOLUTION	0x02

#define COMMAND_SETCONFIG	0x03

#define COMMAND_DATAREQUEST	0x04

#define COMMAND_SCANFREQ	0x08

#define COMMAND_STATUS		0X1e

/*
 * Responses the controller sends as a result of
 * command requests
 */

#define RESPONSE_DEACTIVATE	0x00

#define RESPONSE_INITIALIZE	0x01

#define RESPONSE_RESOLUTION	0x02

#define RESPONSE_SETCONFIG	0x03

#define RESPONSE_SCANFREQ	0x08

#define RESPONSE_STATUS		0X1e

/*
 * Notifications are sent by the touch controller without
 * being requested by the driver and include for example
 * touch indications
 */

#define NOTIFICATION_TOUCH		0x04

#define NOTIFICATION_BOOTCOMPLETE	0x07

#define NOTIFICATION_OVERRUN		0x25

#define NOTIFICATION_PROXIMITY		0x26

#define NOTIFICATION_INVALID_COMMAND	0xfe


#define ZFORCE_REPORT_POINTS		2

#define ZFORCE_MAX_AREA			0xff


#define STATE_DOWN			0

#define STATE_MOVE			1

#define STATE_UP			2


#define SETCONFIG_DUALTOUCH		(1 << 0)


struct zforce_point {
	
int coord_x;
	
int coord_y;
	
int state;
	
int id;
	
int area_major;
	
int area_minor;
	
int orientation;
	
int pressure;
	
int prblty;
};

/*
 * @client              the i2c_client
 * @input               the input device
 * @suspending          in the process of going to suspend (don't emit wakeup
 *                      events for commands executed to suspend the device)
 * @suspended           device suspended
 * @access_mutex        serialize i2c-access, to keep multipart reads together
 * @command_done        completion to wait for the command result
 * @command_mutex       serialize commands sent to the ic
 * @command_waiting     the id of the command that is currently waiting
 *                      for a result
 * @command_result      returned result of the command
 */

struct zforce_ts {
	
struct i2c_client	*client;
	
struct input_dev	*input;
	
const struct zforce_ts_platdata *pdata;
	
char			phys[32];

	
struct regulator	*reg_vdd;

	
struct gpio_desc	*gpio_int;
	
struct gpio_desc	*gpio_rst;

	
bool			suspending;
	
bool			suspended;
	
bool			boot_complete;

	/* Firmware version information */
	
u16			version_major;
	
u16			version_minor;
	
u16			version_build;
	
u16			version_rev;

	
struct mutex		access_mutex;

	
struct completion	command_done;
	
struct mutex		command_mutex;
	
int			command_waiting;
	
int			command_result;
};


static int zforce_command(struct zforce_ts *ts, u8 cmd) { struct i2c_client *client = ts->client; char buf[3]; int ret; dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd); buf[0] = FRAME_START; buf[1] = 1; /* data size, command only */ buf[2] = cmd; mutex_lock(&ts->access_mutex); ret = i2c_master_send(client, &buf[0], ARRAY_SIZE(buf)); mutex_unlock(&ts->access_mutex); if (ret < 0) { dev_err(&client->dev, "i2c send data request error: %d\n", ret); return ret; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner128100.00%1100.00%
Total128100.00%1100.00%


static void zforce_reset_assert(struct zforce_ts *ts) { gpiod_set_value_cansleep(ts->gpio_rst, 1); }

Contributors

PersonTokensPropCommitsCommitProp
Dirk Behme20100.00%1100.00%
Total20100.00%1100.00%


static void zforce_reset_deassert(struct zforce_ts *ts) { gpiod_set_value_cansleep(ts->gpio_rst, 0); }

Contributors

PersonTokensPropCommitsCommitProp
Dirk Behme20100.00%1100.00%
Total20100.00%1100.00%


static int zforce_send_wait(struct zforce_ts *ts, const char *buf, int len) { struct i2c_client *client = ts->client; int ret; ret = mutex_trylock(&ts->command_mutex); if (!ret) { dev_err(&client->dev, "already waiting for a command\n"); return -EBUSY; } dev_dbg(&client->dev, "sending %d bytes for command 0x%x\n", buf[1], buf[2]); ts->command_waiting = buf[2]; mutex_lock(&ts->access_mutex); ret = i2c_master_send(client, buf, len); mutex_unlock(&ts->access_mutex); if (ret < 0) { dev_err(&client->dev, "i2c send data request error: %d\n", ret); goto unlock; } dev_dbg(&client->dev, "waiting for result for command 0x%x\n", buf[2]); if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0) { ret = -ETIME; goto unlock; } ret = ts->command_result; unlock: mutex_unlock(&ts->command_mutex); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner199100.00%1100.00%
Total199100.00%1100.00%


static int zforce_command_wait(struct zforce_ts *ts, u8 cmd) { struct i2c_client *client = ts->client; char buf[3]; int ret; dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd); buf[0] = FRAME_START; buf[1] = 1; /* data size, command only */ buf[2] = cmd; ret = zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf)); if (ret < 0) { dev_err(&client->dev, "i2c send data request error: %d\n", ret); return ret; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner112100.00%1100.00%
Total112100.00%1100.00%


static int zforce_resolution(struct zforce_ts *ts, u16 x, u16 y) { struct i2c_client *client = ts->client; char buf[7] = { FRAME_START, 5, COMMAND_RESOLUTION, (x & 0xff), ((x >> 8) & 0xff), (y & 0xff), ((y >> 8) & 0xff) }; dev_dbg(&client->dev, "set resolution to (%d,%d)\n", x, y); return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf)); }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner103100.00%1100.00%
Total103100.00%1100.00%


static int zforce_scan_frequency(struct zforce_ts *ts, u16 idle, u16 finger, u16 stylus) { struct i2c_client *client = ts->client; char buf[9] = { FRAME_START, 7, COMMAND_SCANFREQ, (idle & 0xff), ((idle >> 8) & 0xff), (finger & 0xff), ((finger >> 8) & 0xff), (stylus & 0xff), ((stylus >> 8) & 0xff) }; dev_dbg(&client->dev, "set scan frequency to (idle: %d, finger: %d, stylus: %d)\n", idle, finger, stylus); return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf)); }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner124100.00%1100.00%
Total124100.00%1100.00%


static int zforce_setconfig(struct zforce_ts *ts, char b1) { struct i2c_client *client = ts->client; char buf[7] = { FRAME_START, 5, COMMAND_SETCONFIG, b1, 0, 0, 0 }; dev_dbg(&client->dev, "set config to (%d)\n", b1); return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf)); }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner74100.00%1100.00%
Total74100.00%1100.00%


static int zforce_start(struct zforce_ts *ts) { struct i2c_client *client = ts->client; const struct zforce_ts_platdata *pdata = ts->pdata; int ret; dev_dbg(&client->dev, "starting device\n"); ret = zforce_command_wait(ts, COMMAND_INITIALIZE); if (ret) { dev_err(&client->dev, "Unable to initialize, %d\n", ret); return ret; } ret = zforce_resolution(ts, pdata->x_max, pdata->y_max); if (ret) { dev_err(&client->dev, "Unable to set resolution, %d\n", ret); goto error; } ret = zforce_scan_frequency(ts, 10, 50, 50); if (ret) { dev_err(&client->dev, "Unable to set scan frequency, %d\n", ret); goto error; } ret = zforce_setconfig(ts, SETCONFIG_DUALTOUCH); if (ret) { dev_err(&client->dev, "Unable to set config\n"); goto error; } /* start sending touch events */ ret = zforce_command(ts, COMMAND_DATAREQUEST); if (ret) { dev_err(&client->dev, "Unable to request data\n"); goto error; } /* * Per NN, initial cal. take max. of 200msec. * Allow time to complete this calibration */ msleep(200); return 0; error: zforce_command_wait(ts, COMMAND_DEACTIVATE); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner21597.29%266.67%
Wei Yongjun62.71%133.33%
Total221100.00%3100.00%


static int zforce_stop(struct zforce_ts *ts) { struct i2c_client *client = ts->client; int ret; dev_dbg(&client->dev, "stopping device\n"); /* Deactivates touch sensing and puts the device into sleep. */ ret = zforce_command_wait(ts, COMMAND_DEACTIVATE); if (ret != 0) { dev_err(&client->dev, "could not deactivate device, %d\n", ret); return ret; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner69100.00%1100.00%
Total69100.00%1100.00%


static int zforce_touch_event(struct zforce_ts *ts, u8 *payload) { struct i2c_client *client = ts->client; const struct zforce_ts_platdata *pdata = ts->pdata; struct zforce_point point; int count, i, num = 0; count = payload[0]; if (count > ZFORCE_REPORT_POINTS) { dev_warn(&client->dev, "too many coordinates %d, expected max %d\n", count, ZFORCE_REPORT_POINTS); count = ZFORCE_REPORT_POINTS; } for (i = 0; i < count; i++) { point.coord_x = payload[9 * i + 2] << 8 | payload[9 * i + 1]; point.coord_y = payload[9 * i + 4] << 8 | payload[9 * i + 3]; if (point.coord_x > pdata->x_max || point.coord_y > pdata->y_max) { dev_warn(&client->dev, "coordinates (%d,%d) invalid\n", point.coord_x, point.coord_y); point.coord_x = point.coord_y = 0; } point.state = payload[9 * i + 5] & 0x0f; point.id = (payload[9 * i + 5] & 0xf0) >> 4; /* determine touch major, minor and orientation */ point.area_major = max(payload[9 * i + 6], payload[9 * i + 7]); point.area_minor = min(payload[9 * i + 6], payload[9 * i + 7]); point.orientation = payload[9 * i + 6] > payload[9 * i + 7]; point.pressure = payload[9 * i + 8]; point.prblty = payload[9 * i + 9]; dev_dbg(&client->dev, "point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n", i, count, point.state, point.id, point.pressure, point.prblty, point.coord_x, point.coord_y, point.area_major, point.area_minor, point.orientation); /* the zforce id starts with "1", so needs to be decreased */ input_mt_slot(ts->input, point.id - 1); input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, point.state != STATE_UP); if (point.state != STATE_UP) { input_report_abs(ts->input, ABS_MT_POSITION_X, point.coord_x); input_report_abs(ts->input, ABS_MT_POSITION_Y, point.coord_y); input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR, point.area_major); input_report_abs(ts->input, ABS_MT_TOUCH_MINOR, point.area_minor); input_report_abs(ts->input, ABS_MT_ORIENTATION, point.orientation); num++; } } input_mt_sync_frame(ts->input); input_mt_report_finger_count(ts->input, num); input_sync(ts->input); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner50399.21%250.00%
Knut Wohlrab30.59%125.00%
Luis Ortega Perez de Villar10.20%125.00%
Total507100.00%4100.00%


static int zforce_read_packet(struct zforce_ts *ts, u8 *buf) { struct i2c_client *client = ts->client; int ret; mutex_lock(&ts->access_mutex); /* read 2 byte message header */ ret = i2c_master_recv(client, buf, 2); if (ret < 0) { dev_err(&client->dev, "error reading header: %d\n", ret); goto unlock; } if (buf[PAYLOAD_HEADER] != FRAME_START) { dev_err(&client->dev, "invalid frame start: %d\n", buf[0]); ret = -EIO; goto unlock; } if (buf[PAYLOAD_LENGTH] == 0) { dev_err(&client->dev, "invalid payload length: %d\n", buf[PAYLOAD_LENGTH]); ret = -EIO; goto unlock; } /* read the message */ ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]); if (ret < 0) { dev_err(&client->dev, "error reading payload: %d\n", ret); goto unlock; } dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n", buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]); unlock: mutex_unlock(&ts->access_mutex); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner21299.53%150.00%
Luis Ortega Perez de Villar10.47%150.00%
Total213100.00%2100.00%


static void zforce_complete(struct zforce_ts *ts, int cmd, int result) { struct i2c_client *client = ts->client; if (ts->command_waiting == cmd) { dev_dbg(&client->dev, "completing command 0x%x\n", cmd); ts->command_result = result; complete(&ts->command_done); } else { dev_dbg(&client->dev, "command %d not for us\n", cmd); } }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner77100.00%1100.00%
Total77100.00%1100.00%


static irqreturn_t zforce_irq(int irq, void *dev_id) { struct zforce_ts *ts = dev_id; struct i2c_client *client = ts->client; if (ts->suspended && device_may_wakeup(&client->dev)) pm_wakeup_event(&client->dev, 500); return IRQ_WAKE_THREAD; }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner56100.00%2100.00%
Total56100.00%2100.00%


static irqreturn_t zforce_irq_thread(int irq, void *dev_id) { struct zforce_ts *ts = dev_id; struct i2c_client *client = ts->client; int ret; u8 payload_buffer[FRAME_MAXSIZE]; u8 *payload; /* * When still suspended, return. * Due to the level-interrupt we will get re-triggered later. */ if (ts->suspended) { msleep(20); return IRQ_HANDLED; } dev_dbg(&client->dev, "handling interrupt\n"); /* Don't emit wakeup events from commands run by zforce_suspend */ if (!ts->suspending && device_may_wakeup(&client->dev)) pm_stay_awake(&client->dev); /* * Run at least once and exit the loop if * - the optional interrupt GPIO isn't specified * (there is only one packet read per ISR invocation, then) * or * - the GPIO isn't active any more * (packet read until the level GPIO indicates that there is * no IRQ any more) */ do { ret = zforce_read_packet(ts, payload_buffer); if (ret < 0) { dev_err(&client->dev, "could not read packet, ret: %d\n", ret); break; } payload = &payload_buffer[PAYLOAD_BODY]; switch (payload[RESPONSE_ID]) { case NOTIFICATION_TOUCH: /* * Always report touch-events received while * suspending, when being a wakeup source */ if (ts->suspending && device_may_wakeup(&client->dev)) pm_wakeup_event(&client->dev, 500); zforce_touch_event(ts, &payload[RESPONSE_DATA]); break; case NOTIFICATION_BOOTCOMPLETE: ts->boot_complete = payload[RESPONSE_DATA]; zforce_complete(ts, payload[RESPONSE_ID], 0); break; case RESPONSE_INITIALIZE: case RESPONSE_DEACTIVATE: case RESPONSE_SETCONFIG: case RESPONSE_RESOLUTION: case RESPONSE_SCANFREQ: zforce_complete(ts, payload[RESPONSE_ID], payload[RESPONSE_DATA]); break; case RESPONSE_STATUS: /* * Version Payload Results * [2:major] [2:minor] [2:build] [2:rev] */ ts->version_major = (payload[RESPONSE_DATA + 1] << 8) | payload[RESPONSE_DATA]; ts->version_minor = (payload[RESPONSE_DATA + 3] << 8) | payload[RESPONSE_DATA + 2]; ts->version_build = (payload[RESPONSE_DATA + 5] << 8) | payload[RESPONSE_DATA + 4]; ts->version_rev = (payload[RESPONSE_DATA + 7] << 8) | payload[RESPONSE_DATA + 6]; dev_dbg(&ts->client->dev, "Firmware Version %04x:%04x %04x:%04x\n", ts->version_major, ts->version_minor, ts->version_build, ts->version_rev); zforce_complete(ts, payload[RESPONSE_ID], 0); break; case NOTIFICATION_INVALID_COMMAND: dev_err(&ts->client->dev, "invalid command: 0x%x\n", payload[RESPONSE_DATA]); break; default: dev_err(&ts->client->dev, "unrecognized response id: 0x%x\n", payload[RESPONSE_ID]); break; } } while (gpiod_get_value_cansleep(ts->gpio_int)); if (!ts->suspending && device_may_wakeup(&client->dev)) pm_relax(&client->dev); dev_dbg(&client->dev, "finished interrupt\n"); return IRQ_HANDLED; }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner44497.16%250.00%
Dirk Behme122.63%125.00%
Luis Ortega Perez de Villar10.22%125.00%
Total457100.00%4100.00%


static int zforce_input_open(struct input_dev *dev) { struct zforce_ts *ts = input_get_drvdata(dev); return zforce_start(ts); }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner2696.30%150.00%
Javier Martinez Canillas13.70%150.00%
Total27100.00%2100.00%


static void zforce_input_close(struct input_dev *dev) { struct zforce_ts *ts = input_get_drvdata(dev); struct i2c_client *client = ts->client; int ret; ret = zforce_stop(ts); if (ret) dev_warn(&client->dev, "stopping zforce failed\n"); return; }

Contributors

PersonTokensPropCommitsCommitProp
Heiko Stübner55100.00%1100.00%
Total55100.00%1100.00%


static int __maybe_unused zforce_suspend(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct zforce_ts *ts = i2c_get_clientdata(client); struct input_dev *input = ts->input; int ret = 0; mutex_lock(&input->mutex); ts->suspending = true; /* * When configured as a wakeup source device should always wake * the system, therefore start device if necessary. */ if (device_may_wakeup(&client->dev)) { dev_dbg(&client->dev, "suspend while being a wakeup source\n"); /* Need to start device, if not open, to be a wakeup source. */ if (!input->users) { ret = zforce_start(ts); if (ret) goto unlock; } enable_irq_wake(client->irq); } else if (input->users) { dev_dbg(&client->dev, "suspend without being a wakeup source\n"); ret = zforce_stop(ts); if (ret) goto unlock; disable_irq(client->irq); } ts->suspended = true; unlock: