Re: [PATCH] input: Add support for the TSC2003 controller.

From: Kwangwoo Lee
Date: Wed Apr 29 2009 - 21:36:00 EST

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In reply to: Trilok Soni: "Re: [PATCH] input: Add support for the TSC2003 controller."
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Hi Thierry and Trilok,

On Wed, Apr 29, 2009 at 10:23 PM, Trilok Soni <soni.trilok@xxxxxxxxx> wrote:
> Hi Thierry,
>
> I have added linux-omap community. How different is this chip from
> tsc2007. It looks to me that this chip is not much different from
> tsc2007 (this is just quick look at the driver). If they
> are similar please consider using i2c_device_id feature in tsc2007 to
> accommodate this chip.

I agree with the Trilok's opinion.
And some comments about the codes below..

> On Wed, Apr 29, 2009 at 5:33 PM, Thierry Reding
> <thierry.reding@xxxxxxxxxxxxxxxxx> wrote:
>> This patch implements touchscreen support for the TSC2003 controller. There is
>> no support for the temperature sensor yet.
>>
>> Signed-off-by: Thierry Reding <thierry.reding@xxxxxxxxxxxxxxxxx>
>>
>> ---
>> drivers/input/touchscreen/Kconfig | 8 +
>> drivers/input/touchscreen/Makefile | 1 +
>> drivers/input/touchscreen/tsc2003.c | 416 +++++++++++++++++++++++++++++++++++
>> include/linux/i2c/tsc2003.h | 28 +++
>> 4 files changed, 453 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
>> index b01fd61..87b980c 100644
>> --- a/drivers/input/touchscreen/Kconfig
>> +++ b/drivers/input/touchscreen/Kconfig
>> @@ -455,6 +455,14 @@ config TOUCHSCREEN_TOUCHIT213
>> To compile this driver as a module, choose M here: the
>> module will be called touchit213.
>>
>> +config TOUCHSCREEN_TSC2003
>> + tristate "Texas Instruments TSC2003 Touchscreen Controller"
>> + depends on I2C
>> + ---help---
>> + If you say yes here you get support for the Texas Instruments
>> + TSC2003 Touchscreen Controller with on-chip temperature
>> + measurement.
>> +
>> config TOUCHSCREEN_TSC2007
>> tristate "TSC2007 based touchscreens"
>> depends on I2C
>> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
>> index 6700f7b..e965422 100644
>> --- a/drivers/input/touchscreen/Makefile
>> +++ b/drivers/input/touchscreen/Makefile
>> @@ -27,6 +27,7 @@ obj-$(CONFIG_TOUCHSCREEN_PENMOUNT) += penmount.o
>> obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213) += touchit213.o
>> obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT) += touchright.o
>> obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN) += touchwin.o
>> +obj-$(CONFIG_TOUCHSCREEN_TSC2003) += tsc2003.o
>> obj-$(CONFIG_TOUCHSCREEN_TSC2007) += tsc2007.o
>> obj-$(CONFIG_TOUCHSCREEN_UCB1400) += ucb1400_ts.o
>> obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001) += wacom_w8001.o
>> diff --git a/drivers/input/touchscreen/tsc2003.c b/drivers/input/touchscreen/tsc2003.c
>> new file mode 100644
>> index 0000000..5acaa0d
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/tsc2003.c
>> @@ -0,0 +1,416 @@
>> +/*
>> + * linux/drivers/input/touchscreen/tsc2003.c
>> + *
>> + * Copyright (C) 2007-2008 Avionic Design Development GmbH
>> + * Copyright (C) 2008-2009 Avionic Design GmbH
>> + *
>> + * 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.
>> + *
>> + * Written by Thierry Reding <thierry.reding@xxxxxxxxxxxxxxxxx>
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/i2c.h>
>> +#include <linux/input.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/i2c/tsc2003.h>
>> +
>> +#define DRIVER_NAME "tsc2003"
>> +#define DRIVER_VERSION "1"
>> +
>> +/* basic commands */
>> +#define CMD_MEASURE_TEMPERATURE_0 0x00
>> +#define CMD_MEASURE_BATTERY_1 0x10
>> +#define CMD_MEASURE_INPUT_1 0x20
>> +#define CMD_MEASURE_TEMPERATURE_1 0x40
>> +#define CMD_MEASURE_BATTERY_2 0x50
>> +#define CMD_MEASURE_INPUT_2 0x60
>> +#define CMD_ACTIVATE_X 0x80
>> +#define CMD_ACTIVATE_Y 0x90
>> +#define CMD_ACTIVATE_XY 0xA0
>> +#define CMD_MEASURE_X 0xC0
>> +#define CMD_MEASURE_Y 0xD0
>> +#define CMD_MEASURE_Z1 0xE0
>> +#define CMD_MEASURE_Z2 0xF0
>> +
>> +/* powerdown modes */
>> +#define PDM_POWERDOWN 0x00
>> +#define PDM_IR_OFF_ADC_ON 0x04
>> +#define PDM_IR_ON_ADC_OFF 0x08
>> +#define PDM_IR_ON_ADC_ON 0x0A
>> +#define PDM_TOUCH_IRQ_OFF 0x04
>> +

Most of the commands are same with tsc2007.

struct tsc2007 has a member variable named model in tsc2007 driver.
It is acquired from platform_data. So I think it can be used to
distinguish chipsets.

>> +/* data width modes */
>> +#define MODE_12BIT 0x00
>> +#define MODE_8BIT 0x02
>> +
>> +/* periodic polling delay and period */
>> +#define TS_POLL_DELAY (1 * 1000000)
>> +#define TS_POLL_PERIOD (5 * 1000000)
>> +
>> +/**
>> + * struct ts_event - touchscreen event structure
>> + * @pendown: state of the pen
>> + * @x: X-coordinate of the event
>> + * @y: Y-coordinate of the event
>> + * @z: pressure of the event
>> + */
>> +struct ts_event {
>> + short pendown;
>> + short x;
>> + short y;
>> + short z;
>> +};
>> +
>> +/**
>> + * struct tsc2003 - touchscreen controller context
>> + * @client: I2C client
>> + * @input: touchscreen input device
>> + * @lock: lock for resource protection
>> + * @timer: timer for periodical polling
>> + * @work: workqueue structure
>> + * @pendown: current pen state
>> + * @event: current touchscreen event
>> + * @pdata: platform-specific information
>> + */
>> +struct tsc2003 {
>> + struct i2c_client *client;
>> + struct input_dev *input;
>> + spinlock_t lock;
>> + struct hrtimer timer;
>> + struct work_struct work;
>> +
>> + struct ts_event event;
>> + unsigned pendown:1;
>> +
>> + struct tsc2003_platform_data *pdata;
>> +};
>> +
>> +/**
>> + * tsc2003_get_pendown_state() - obtain the current pen state
>> + * @ts: touchscreen controller context
>> + */
>> +static int tsc2003_get_pendown_state(struct tsc2003 *ts)
>> +{
>> + int state = 0;
>> +
>> + if (ts && ts->pdata && ts->pdata->get_irq_level)
>> + state = !ts->pdata->get_irq_level();
>> +
>> + return state;
>> +}
>> +
>> +/**
>> + * tsc2003_read() - send a command and read the response
>> + * @client: I2C client
>> + * @command: command to send
>> + */
>> +static int tsc2003_read(struct i2c_client *client, u8 command)
>> +{
>> + u8 value[2] = { 0, 0 };
>> + int size = 2;
>> + int status;
>> +
>> + command &= ~MODE_8BIT;
>> +
>> + status = i2c_master_send(client, &command, 1);
>> + if (status < 0)
>> + return status;
>> +
>> + if (command & MODE_8BIT)
>> + size = 1;
>> +
>> + status = i2c_master_recv(client, value, size);
>> + if (status < 0)
>> + return status;
>> +
>> + if (command & MODE_8BIT)
>> + return value[0];
>> +
>> + return (value[0] << 4) | (value[1] >> 4);
>> +}

Jean said that these two APIs can be racy in tsc2007 driver.
So I used i2c_smbus_read_word_data() to replace it.

>> +
>> +/**
>> + * tsc2003_read_x() - read touch screen X-coordinate
>> + * @client: I2C client
>> + * @pdm: powerdown mode
>> + * @samples: number of samples to average over
>> + */
>> +static int tsc2003_read_x(struct i2c_client *client, u8 pdm, int samples)
>> +{
>> + return tsc2003_read(client, CMD_MEASURE_X | pdm);
>> +}
>> +
>> +/**
>> + * tsc2003_read_y() - read touch screen Y-coordinate
>> + * @client: I2C client
>> + * @pdm: powerdown mode
>> + * @samples: number of samples to average over
>> + */
>> +static int tsc2003_read_y(struct i2c_client *client, u8 pdm, int samples)
>> +{
>> + return tsc2003_read(client, CMD_MEASURE_Y | pdm);
>> +}
>> +
>> +/**
>> + * tsc2003_read_z() - read touch screen pressure
>> + * @client: I2C client
>> + * @pdm: powerdown mode
>> + * @samples: number of samples to average over
>> + */
>> +static int tsc2003_read_z(struct i2c_client *client, u8 pdm, int samples)
>> +{
>> + int p1 = tsc2003_read(client, CMD_MEASURE_Z1 | pdm);
>> + int p2 = tsc2003_read(client, CMD_MEASURE_Z2 | pdm);
>> +
>> + p2 = 0;
>> +
>> + return p1;
>> +}
>> +
>> +/**
>> + * tsc2003_timer() - timer callback function
>> + * @timer: timer that caused this function call
>> + */
>> +static enum hrtimer_restart tsc2003_timer(struct hrtimer *timer)
>> +{
>> + struct tsc2003 *ts = container_of(timer, struct tsc2003, timer);
>> + unsigned long flags = 0;
>> + int state = 0;
>> +
>> + spin_lock_irqsave(&ts->lock, flags);
>> +
>> + state = tsc2003_get_pendown_state(ts);
>> + if (state) {
>> + /* reset if this is the first pen down event */
>> + if (!ts->pendown) {
>> + ts->event.pendown = 0;
>> + ts->pendown = 1;
>> + }
>> +
>> + schedule_work(&ts->work);
>> + } else {
>> + /* enable IRQ after the pen was lifted */
>> + if (ts->pendown)
>> + ts->pendown = 0;
>> +
>> + input_report_key(ts->input, BTN_TOUCH, 0);
>> + input_report_abs(ts->input, ABS_PRESSURE, 0);
>> + input_sync(ts->input);
>> +
>> + enable_irq(ts->client->irq);
>> + }
>> +
>> + spin_unlock_irqrestore(&ts->lock, flags);
>> + return HRTIMER_NORESTART;
>> +}
>> +
>> +/**
>> + * tsc2003_work() - work queue handler (initiated by the interrupt handler)
>> + * @work: work queue to handle
>> + */
>> +static void tsc2003_work(struct work_struct *work)
>> +{
>> + struct tsc2003 *ts = container_of(work, struct tsc2003, work);
>> +
>> + /* report only the first pen down event */
>> + if (!ts->event.pendown) {
>> + input_report_key(ts->input, BTN_TOUCH, 1);
>> + ts->event.pendown = 1;
>> + }
>> +
>> + /* read X- and Y-coordinates and the pressure */
>> + ts->event.x = tsc2003_read_x(ts->client, PDM_POWERDOWN, 1);
>> + ts->event.y = tsc2003_read_y(ts->client, PDM_POWERDOWN, 1);
>> + ts->event.z = tsc2003_read_z(ts->client, PDM_POWERDOWN, 1);
>> +
>> + /* report X- and Y-coordinates and the pressure */
>> + input_report_abs(ts->input, ABS_X, ts->event.x);
>> + input_report_abs(ts->input, ABS_Y, ts->event.y);
>> + input_report_abs(ts->input, ABS_PRESSURE, ts->event.z);
>> + input_sync(ts->input);
>> +
>> + /* restart the timer */
>> + hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
>> + HRTIMER_MODE_REL);
>> +}
>> +
>> +/**
>> + * tsc2003_interrupt() - interrupt handler for touch events
>> + * @irq: interrupt to handle
>> + * @dev_id: device-specific information
>> + */
>> +static irqreturn_t tsc2003_interrupt(int irq, void *dev_id)
>> +{
>> + struct i2c_client *client = (struct i2c_client *)dev_id;
>> + struct tsc2003 *ts = i2c_get_clientdata(client);
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&ts->lock, flags);
>> +
>> + /* if the pen is down, disable IRQ and start timer chain */
>> + if (tsc2003_get_pendown_state(ts)) {
>> + disable_irq_nosync(client->irq);
>> + hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
>> + HRTIMER_MODE_REL);
>> + }
>> +
>> + spin_unlock_irqrestore(&ts->lock, flags);
>> + return IRQ_HANDLED;
>> +}
>> +
>> +/**
>> + * tsc2003_probe() - initialize the I2C client
>> + * @client: client to initialize
>> + * @id: I2C device ID
>> + */
>> +static int tsc2003_probe(struct i2c_client *client,
>> + const struct i2c_device_id *id)
>> +{
>> + struct tsc2003 *ts;
>> + int err = 0;
>> +
>> + ts = kzalloc(sizeof(*ts), GFP_KERNEL);
>> + if (!ts) {
>> + err = -ENOMEM;
>> + goto fail;
>> + }
>> +
>> + ts->client = client;
>> +
>> + ts->input = input_allocate_device();
>> + if (!ts->input) {
>> + err = -ENOMEM;
>> + goto fail;
>> + }
>> +
>> + /* setup the input device */
>> + ts->input->name = "Texas Instruments TSC2003 I2C Touchscreen";
>> + ts->input->phys = DRIVER_NAME "/input0";
>> + ts->input->id.bustype = BUS_I2C;
>> + ts->input->dev.parent = &client->dev;
>> +
>> + ts->input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
>> + ts->input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
>> + input_set_abs_params(ts->input, ABS_X, 0, 0x3ff, 0, 0);
>> + input_set_abs_params(ts->input, ABS_Y, 0, 0x3ff, 0, 0);
>> + input_set_abs_params(ts->input, ABS_PRESSURE, 0, 0x3ff, 0, 0);
>> +
>> + /* setup platform-specific hooks */
>> + ts->pdata = client->dev.platform_data;
>> + if (!ts->pdata || !ts->pdata->init_irq || !ts->pdata->get_irq_level) {
>> + dev_err(&client->dev, "no platform-specific callbacks "
>> + "provided\n");
>> + err = -ENXIO;
>> + goto fail;
>> + }
>> +
>> + if (ts->pdata->init_irq) {
>> + err = ts->pdata->init_irq();
>> + if (err < 0) {
>> + dev_err(&client->dev, "failed to initialize IRQ#%d: "
>> + "%d\n", client->irq, err);
>> + goto fail;
>> + }
>> + }
>> +
>> + spin_lock_init(&ts->lock);
>> + hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
>> + ts->timer.function = tsc2003_timer;
>> + INIT_WORK(&ts->work, tsc2003_work);
>> + ts->pendown = 0;
>> +
>> + err = request_irq(client->irq, tsc2003_interrupt, IRQF_SHARED,
>> + "TSC2003 Touch Screen", client);
>> + if (err) {
>> + dev_err(&client->dev, "failed to request IRQ#%d: %d\n",
>> + client->irq, err);
>> + goto fail;
>> + }
>> +
>> + i2c_set_clientdata(client, ts);
>> +
>> + err = input_register_device(ts->input);
>> + if (err) {
>> + dev_err(&client->dev, "failed to register input device: %d\n",
>> + err);
>> + goto fail_irq;
>> + }
>> +
>> + /* dummy read; necessary to enable the pen IRQ */
>> + (void)tsc2003_read_z(client, PDM_POWERDOWN, 1);
>> + err = 0;
>> + goto out;
>> +
>> +fail_irq:
>> + free_irq(client->irq, client);
>> +
>> +fail:
>> + if (ts) {
>> + input_free_device(ts->input);
>> + kfree(ts);
>> + }
>> +
>> + i2c_set_clientdata(client, NULL);
>> +out:
>> + return err;
>> +}
>> +
>> +/**
>> + * tsc2003_remove() - cleanup the I2C client
>> + * @client: client to clean up
>> + */
>> +static int tsc2003_remove(struct i2c_client *client)
>> +{
>> + struct tsc2003 *priv = i2c_get_clientdata(client);
>> +
>> + free_irq(client->irq, client);
>> + i2c_set_clientdata(client, NULL);
>> + input_unregister_device(priv->input);
>> + kfree(priv);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct i2c_device_id tsc2003_ids[] = {
>> + { DRIVER_NAME, 0 },
>> + { }
>> +};
>> +
>> +/* TSC2003 I2C driver */
>> +static struct i2c_driver tsc2003_driver = {
>> + .driver = {
>> + .name = DRIVER_NAME,
>> + .owner = THIS_MODULE,
>> + },
>> + .probe = tsc2003_probe,
>> + .remove = __devexit_p(tsc2003_remove),
>> + .id_table = tsc2003_ids,
>> +};
>> +
>> +/**
>> + * tsc2003_init() - module initialization
>> + */
>> +static int __init tsc2003_init(void)
>> +{
>> + return i2c_add_driver(&tsc2003_driver);
>> +}
>> +
>> +/**
>> + * tsc2003_exit() - module cleanup
>> + */
>> +static void __exit tsc2003_exit(void)
>> +{
>> + i2c_del_driver(&tsc2003_driver);
>> +}
>> +
>> +module_init(tsc2003_init);
>> +module_exit(tsc2003_exit);
>> +
>> +MODULE_AUTHOR("Thierry Reding <thierry.reding@xxxxxxxxxxxxxxxxx>");
>> +MODULE_DESCRIPTION("Texas Instruments TSC2003 I2C Touch Screen driver");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_VERSION(DRIVER_VERSION);
>> +
>> diff --git a/include/linux/i2c/tsc2003.h b/include/linux/i2c/tsc2003.h
>> new file mode 100644
>> index 0000000..45e6100
>> --- /dev/null
>> +++ b/include/linux/i2c/tsc2003.h
>> @@ -0,0 +1,28 @@
>> +/**
>> + * linux/include/i2c/tsc2003.h
>> + *
>> + * Copyright (C) 2007-2008 Avionic Design Development GmbH
>> + * Copyright (C) 2008-2009 Avionic Design GmbH
>> + *
>> + * This file is subject to the terms and conditions of the GNU General Public
>> + * License. See the file COPYING in the main directory of this archive for
>> + * more details.
>> + *
>> + * Written by Thierry Reding <thierry.reding@xxxxxxxxxxxxxxxxx>
>> + */
>> +
>> +#ifndef LINUX_I2C_TSC2003_H
>> +#define LINUX_I2C_TSC2003_H
>> +
>> +/**
>> + * struct tsc2003_platform_data - platform-specific TSC2003 data
>> + * @init_irq: initialize interrupt
>> + * @get_irq_level: obtain current interrupt level
>> + */
>> +struct tsc2003_platform_data {
>> + int (*init_irq)(void);
>> + int (*get_irq_level)(void);
>> +};
>> +
>> +#endif /* !LINUX_I2C_TSC2003_H */
>> +
>> --
>> tg: (fb160d7..) adx/i2c/tsc2003 (depends on: adx/master)
>> --
> ---Trilok Soni
> http://triloksoni.wordpress.com
> http://www.linkedin.com/in/triloksoni

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Kwangwoo Lee <kwangwoo.lee@xxxxxxxxx>
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Next message: Tejun Heo: "Re: [PATCH] [Target_Core_Mod/pSCSI]: Add block/blk-map.c:blk_rq_map_kern_sg()usage"
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In reply to: Trilok Soni: "Re: [PATCH] input: Add support for the TSC2003 controller."
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