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02228658df7d84d384ea622d848920da170281da
i2som-imx-linux/drivers/input/touchscreen/max11801_ts.c
Robert Chiras 1f497f31f3 MLK-14473: touchscreen: Fix return type 
The touchscreen driver, max11801, which is on 12c2 bus, won't be probed
when using the hdcp specific DTS (this is disabling 12c2, since it
will acquire it for DDC communications). Since this driver won't be
probed, it will spam the dmesg with the pr_err from max11801_read_adc()
function. This function is periodically called by the battery driver. For
this reason, I removed the pr_err() call.
Also, to be noticed that the function signature is u32, but in case of an
error it will return a negative integer. In order to correctly propagate
errors, I changed the function signature to int. This is safe, since the
read value from i2c is on 16 bits (MSB and LSB on 8 bits).

Also, the function calibration_voltage is calling max11801_read_adc from
touchscreen driverm which can return negative values in case of an
error. I case of an error, just stop reading ADC data and return 0 as
voltage_data.

Signed-off-by: Robert Chiras <robert.chiras@nxp.com>
2019-02-12 10:26:05 +08:00

378 lines
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/*
* Driver for MAXI MAX11801 - A Resistive touch screen controller with
* i2c interface
*
* Copyright (C) 2011-2015 Freescale Semiconductor, Inc.
* Author: Zhang Jiejing <jiejing.zhang@freescale.com>
*
* Based on mcs5000_ts.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
/*
* This driver aims to support the series of MAXI touch chips max11801
* through max11803. The main difference between these 4 chips can be
* found in the table below:
* -----------------------------------------------------
* | CHIP | AUTO MODE SUPPORT(FIFO) | INTERFACE |
* |----------------------------------------------------|
* | max11800 | YES | SPI |
* | max11801 | YES | I2C |
* | max11802 | NO | SPI |
* | max11803 | NO | I2C |
* ------------------------------------------------------
*
* Currently, this driver only supports max11801.
*
* Data Sheet:
* http://www.maxim-ic.com/datasheet/index.mvp/id/5943
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_device.h>
/* Register Address define */
#define GENERNAL_STATUS_REG 0x00
#define GENERNAL_CONF_REG 0x01
#define MESURE_RES_CONF_REG 0x02
#define MESURE_AVER_CONF_REG 0x03
#define ADC_SAMPLE_TIME_CONF_REG 0x04
#define PANEL_SETUPTIME_CONF_REG 0x05
#define DELAY_CONVERSION_CONF_REG 0x06
#define TOUCH_DETECT_PULLUP_CONF_REG 0x07
#define AUTO_MODE_TIME_CONF_REG 0x08 /* only for max11800/max11801 */
#define APERTURE_CONF_REG 0x09 /* only for max11800/max11801 */
#define AUX_MESURE_CONF_REG 0x0a
#define OP_MODE_CONF_REG 0x0b
#define Panel_Setup_X (0x69 << 1)
#define Panel_Setup_Y (0x6b << 1)
#define XY_combined_measurement (0x70 << 1)
#define X_measurement (0x78 << 1)
#define Y_measurement (0x7a << 1)
#define AUX_measurement (0x76 << 1)
/* FIFO is found only in max11800 and max11801 */
#define FIFO_RD_CMD (0x50 << 1)
#define MAX11801_FIFO_INT (1 << 2)
#define MAX11801_FIFO_OVERFLOW (1 << 3)
#define MAX11801_EDGE_INT (1 << 1)
#define FIFO_RD_X_MSB (0x52 << 1)
#define FIFO_RD_X_LSB (0x53 << 1)
#define FIFO_RD_Y_MSB (0x54 << 1)
#define FIFO_RD_Y_LSB (0x55 << 1)
#define FIFO_RD_AUX_MSB (0x5a << 1)
#define FIFO_RD_AUX_LSB (0x5b << 1)
#define XY_BUFSIZE 4
#define XY_BUF_OFFSET 4
#define AUX_BUFSIZE 2
#define MAX11801_MAX_X 0xfff
#define MAX11801_MAX_Y 0xfff
#define MEASURE_TAG_OFFSET 2
#define MEASURE_TAG_MASK (3 << MEASURE_TAG_OFFSET)
#define EVENT_TAG_OFFSET 0
#define EVENT_TAG_MASK (3 << EVENT_TAG_OFFSET)
#define MEASURE_X_TAG (0 << MEASURE_TAG_OFFSET)
#define MEASURE_Y_TAG (1 << MEASURE_TAG_OFFSET)
/* These are the state of touch event state machine */
enum {
EVENT_INIT,
EVENT_MIDDLE,
EVENT_RELEASE,
EVENT_FIFO_END
};
struct max11801_data {
struct i2c_client *client;
struct input_dev *input_dev;
};
static struct i2c_client *max11801_client;
static unsigned int max11801_workmode;
static u8 aux_buf[AUX_BUFSIZE];
static int max11801_dcm_write_command(struct i2c_client *client, int command)
{
return i2c_smbus_write_byte(client, command);
}
static int max11801_dcm_sample_aux(struct i2c_client *client)
{
int ret;
int aux = 0;
int sample_data;
/* AUX_measurement */
max11801_dcm_write_command(client, AUX_measurement);
mdelay(5);
ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_AUX_MSB,
1, &aux_buf[0]);
if (ret < 0) {
dev_err(&client->dev, "FIFO_RD_AUX_MSB read failed (%d)\n",
ret);
return ret;
}
mdelay(5);
ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_AUX_LSB,
1, &aux_buf[1]);
if (ret < 0) {
dev_err(&client->dev, "FIFO_RD_AUX_LSB read failed (%d)\n",
ret);
return ret;
}
aux = (aux_buf[0] << 4) + (aux_buf[1] >> 4);
/*
* voltage = (9170*aux)/7371;
* voltage is (26.2*3150*aux)/(16.2*0xFFF)
* V(aux)=3150*sample/0xFFF,V(battery)=212*V(aux)/81
* sample_data = (14840*aux)/7371-1541;
*/
sample_data = (14840 * aux) / 7371;
return sample_data;
}
int max11801_read_adc(void)
{
int adc_data;
if (!max11801_client)
return -ENODEV;
adc_data = max11801_dcm_sample_aux(max11801_client);
return adc_data;
}
EXPORT_SYMBOL_GPL(max11801_read_adc);
static u8 read_register(struct i2c_client *client, int addr)
{
/* XXX: The chip ignores LSB of register address */
return i2c_smbus_read_byte_data(client, addr << 1);
}
static int max11801_write_reg(struct i2c_client *client, int addr, int data)
{
/* XXX: The chip ignores LSB of register address */
return i2c_smbus_write_byte_data(client, addr << 1, data);
}
static irqreturn_t max11801_ts_interrupt(int irq, void *dev_id)
{
struct max11801_data *data = dev_id;
struct i2c_client *client = data->client;
int status, i, ret;
u8 buf[XY_BUFSIZE];
int x = -1;
int y = -1;
u8 command = FIFO_RD_X_MSB;
status = read_register(data->client, GENERNAL_STATUS_REG);
if ((!max11801_workmode && (status & (MAX11801_FIFO_INT |
MAX11801_FIFO_OVERFLOW))) || (max11801_workmode && (status &
MAX11801_EDGE_INT))) {
status = read_register(data->client, GENERNAL_STATUS_REG);
if (!max11801_workmode) {
/* ACM mode */
ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_CMD,
XY_BUFSIZE, buf);
/*
* We should get 4 bytes buffer that contains X,Y
* and event tag
*/
if (ret < XY_BUFSIZE)
goto out;
} else {
/* DCM mode */
/* X = panel setup */
max11801_dcm_write_command(client, Panel_Setup_X);
/* X_measurement */
max11801_dcm_write_command(client, X_measurement);
for (i = 0; i < 2; i++) {
ret = i2c_smbus_read_i2c_block_data(client,
command, 1, &buf[i]);
if (ret < 1)
goto out;
command = FIFO_RD_X_LSB;
}
/* Y = panel setup */
max11801_dcm_write_command(client, Panel_Setup_Y);
/* Y_measurement */
max11801_dcm_write_command(client, Y_measurement);
command = FIFO_RD_Y_MSB;
for (i = 2; i < XY_BUFSIZE; i++) {
ret = i2c_smbus_read_i2c_block_data(client,
command, 1, &buf[i]);
if (ret < 1)
goto out;
command = FIFO_RD_Y_LSB;
}
}
for (i = 0; i < XY_BUFSIZE; i += XY_BUFSIZE / 2) {
if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_X_TAG)
x = (buf[i] << XY_BUF_OFFSET) +
(buf[i + 1] >> XY_BUF_OFFSET);
else if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_Y_TAG)
y = (buf[i] << XY_BUF_OFFSET) +
(buf[i + 1] >> XY_BUF_OFFSET);
}
if ((buf[1] & EVENT_TAG_MASK) != (buf[3] & EVENT_TAG_MASK))
goto out;
switch (buf[1] & EVENT_TAG_MASK) {
case EVENT_INIT:
/* fall through */
case EVENT_MIDDLE:
input_report_abs(data->input_dev, ABS_X, x);
y = MAX11801_MAX_Y - y; /* Calibration */
input_report_abs(data->input_dev, ABS_Y, y);
input_event(data->input_dev, EV_KEY, BTN_TOUCH, 1);
input_sync(data->input_dev);
break;
case EVENT_RELEASE:
input_event(data->input_dev, EV_KEY, BTN_TOUCH, 0);
input_sync(data->input_dev);
break;
case EVENT_FIFO_END:
break;
}
}
out:
return IRQ_HANDLED;
}
static void max11801_ts_phy_init(struct max11801_data *data)
{
struct i2c_client *client = data->client;
max11801_client = client;
/* Average X,Y, take 16 samples average eight media sample */
max11801_write_reg(client, MESURE_AVER_CONF_REG, 0xff);
/* X,Y panel setup time set to 20us */
max11801_write_reg(client, PANEL_SETUPTIME_CONF_REG, 0x11);
/* Rough pullup time (2uS), Fine pullup time (10us) */
max11801_write_reg(client, TOUCH_DETECT_PULLUP_CONF_REG, 0x10);
/* Auto mode init period = 5ms , scan period = 5ms*/
max11801_write_reg(client, AUTO_MODE_TIME_CONF_REG, 0xaa);
/* Aperture X,Y set to +- 4LSB */
max11801_write_reg(client, APERTURE_CONF_REG, 0x33);
/* Enable Power, enable Automode, enable Aperture, enable Average X,Y */
if (!max11801_workmode)
max11801_write_reg(client, OP_MODE_CONF_REG, 0x36);
else {
max11801_write_reg(client, OP_MODE_CONF_REG, 0x16);
/*
* Delay initial=1ms, Sampling time 2us
* Averaging sample depth 2
* samples, Resolution 12bit
*/
max11801_write_reg(client, AUX_MESURE_CONF_REG, 0x76);
/*
* Use edge interrupt with
* direct conversion mode
*/
max11801_write_reg(client, GENERNAL_CONF_REG, 0xf3);
}
}
static int max11801_ts_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct max11801_data *data;
struct input_dev *input_dev;
int error;
struct device_node *of_node = client->dev.of_node;
data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
input_dev = devm_input_allocate_device(&client->dev);
if (!data || !input_dev) {
dev_err(&client->dev, "Failed to allocate memory\n");
return -ENOMEM;
}
data->client = client;
data->input_dev = input_dev;
input_dev->name = "max11801_ts";
input_dev->id.bustype = BUS_I2C;
input_dev->dev.parent = &client->dev;
__set_bit(EV_ABS, input_dev->evbit);
__set_bit(EV_KEY, input_dev->evbit);
__set_bit(BTN_TOUCH, input_dev->keybit);
input_set_abs_params(input_dev, ABS_X, 0, MAX11801_MAX_X, 0, 0);
input_set_abs_params(input_dev, ABS_Y, 0, MAX11801_MAX_Y, 0, 0);
if (of_property_read_u32(of_node, "work-mode", &max11801_workmode))
max11801_workmode = *(int *)(client->dev).platform_data;
max11801_ts_phy_init(data);
error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
max11801_ts_interrupt,
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
"max11801_ts", data);
if (error) {
dev_err(&client->dev, "Failed to register interrupt\n");
return error;
}
error = input_register_device(data->input_dev);
if (error)
return error;
return 0;
}
static const struct i2c_device_id max11801_ts_id[] = {
{"max11801", 0},
{ }
};
MODULE_DEVICE_TABLE(i2c, max11801_ts_id);
static const struct of_device_id max11801_ts_dt_ids[] = {
{ .compatible = "maxim,max11801" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, max11801_ts_dt_ids);
static struct i2c_driver max11801_ts_driver = {
.driver = {
.name = "max11801_ts",
.of_match_table = max11801_ts_dt_ids,
},
.id_table = max11801_ts_id,
.probe = max11801_ts_probe,
};
module_i2c_driver(max11801_ts_driver);
MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");
MODULE_DESCRIPTION("Touchscreen driver for MAXI MAX11801 controller");
MODULE_LICENSE("GPL");
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