--- /dev/null
+/*
+ * Driver for MAXI MAX11801 - A Resistive touch screen controller with
+ * i2c interface
+ *
+ * Copyright (C) 2011 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>
+
+/* 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
+
+/* 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 XY_BUFSIZE 4
+#define XY_BUF_OFFSET 4
+
+#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 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;
+
+ status = read_register(data->client, GENERNAL_STATUS_REG);
+
+ if (status & (MAX11801_FIFO_INT | MAX11801_FIFO_OVERFLOW)) {
+ status = read_register(data->client, GENERNAL_STATUS_REG);
+
+ 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;
+
+ 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);
+ 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;
+
+ /* 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 */
+ max11801_write_reg(client, OP_MODE_CONF_REG, 0x36);
+}
+
+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;
+
+ 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);
+ input_set_drvdata(input_dev, 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;
+
+ i2c_set_clientdata(client, data);
+ return 0;
+}
+
+static const struct i2c_device_id max11801_ts_id[] = {
+ {"max11801", 0},
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, max11801_ts_id);
+
+static struct i2c_driver max11801_ts_driver = {
+ .driver = {
+ .name = "max11801_ts",
+ .owner = THIS_MODULE,
+ },
+ .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");
Code Review / kvmfornfv.git / blobdiff