2
* Synaptics touchpad with I2C interface
4
* Copyright (C) 2009 Compulab, Ltd.
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* Mike Rapoport <mike@compulab.co.il>
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* Igor Grinberg <grinberg@compulab.co.il>
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive for
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#include <linux/module.h>
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#include <linux/i2c.h>
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#include <linux/irq.h>
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#include <linux/interrupt.h>
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#include <linux/input.h>
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#include <linux/delay.h>
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#include <linux/workqueue.h>
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#include <linux/slab.h>
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#define DRIVER_NAME "synaptics_i2c"
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/* maximum product id is 15 characters */
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#define PRODUCT_ID_LENGTH 15
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#define REGISTER_LENGTH 8
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* after soft reset, we should wait for 1 ms
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* before the device becomes operational
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#define SOFT_RESET_DELAY_MS 3
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/* and after hard reset, we should wait for max 500ms */
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#define HARD_RESET_DELAY_MS 500
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/* Registers by SMBus address */
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#define PAGE_SEL_REG 0xff
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#define DEVICE_STATUS_REG 0x09
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/* Registers by RMI address */
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#define DEV_CONTROL_REG 0x0000
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#define INTERRUPT_EN_REG 0x0001
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#define ERR_STAT_REG 0x0002
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#define INT_REQ_STAT_REG 0x0003
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#define DEV_COMMAND_REG 0x0004
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#define RMI_PROT_VER_REG 0x0200
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#define MANUFACT_ID_REG 0x0201
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#define PHYS_INT_VER_REG 0x0202
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#define PROD_PROPERTY_REG 0x0203
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#define INFO_QUERY_REG0 0x0204
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#define INFO_QUERY_REG1 (INFO_QUERY_REG0 + 1)
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#define INFO_QUERY_REG2 (INFO_QUERY_REG0 + 2)
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#define INFO_QUERY_REG3 (INFO_QUERY_REG0 + 3)
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#define PRODUCT_ID_REG0 0x0210
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#define PRODUCT_ID_REG1 (PRODUCT_ID_REG0 + 1)
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#define PRODUCT_ID_REG2 (PRODUCT_ID_REG0 + 2)
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#define PRODUCT_ID_REG3 (PRODUCT_ID_REG0 + 3)
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#define PRODUCT_ID_REG4 (PRODUCT_ID_REG0 + 4)
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#define PRODUCT_ID_REG5 (PRODUCT_ID_REG0 + 5)
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#define PRODUCT_ID_REG6 (PRODUCT_ID_REG0 + 6)
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#define PRODUCT_ID_REG7 (PRODUCT_ID_REG0 + 7)
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#define PRODUCT_ID_REG8 (PRODUCT_ID_REG0 + 8)
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#define PRODUCT_ID_REG9 (PRODUCT_ID_REG0 + 9)
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#define PRODUCT_ID_REG10 (PRODUCT_ID_REG0 + 10)
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#define PRODUCT_ID_REG11 (PRODUCT_ID_REG0 + 11)
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#define PRODUCT_ID_REG12 (PRODUCT_ID_REG0 + 12)
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#define PRODUCT_ID_REG13 (PRODUCT_ID_REG0 + 13)
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#define PRODUCT_ID_REG14 (PRODUCT_ID_REG0 + 14)
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#define PRODUCT_ID_REG15 (PRODUCT_ID_REG0 + 15)
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#define DATA_REG0 0x0400
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#define ABS_PRESSURE_REG 0x0401
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#define ABS_MSB_X_REG 0x0402
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#define ABS_LSB_X_REG (ABS_MSB_X_REG + 1)
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#define ABS_MSB_Y_REG 0x0404
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#define ABS_LSB_Y_REG (ABS_MSB_Y_REG + 1)
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#define REL_X_REG 0x0406
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#define REL_Y_REG 0x0407
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#define DEV_QUERY_REG0 0x1000
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#define DEV_QUERY_REG1 (DEV_QUERY_REG0 + 1)
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#define DEV_QUERY_REG2 (DEV_QUERY_REG0 + 2)
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#define DEV_QUERY_REG3 (DEV_QUERY_REG0 + 3)
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#define DEV_QUERY_REG4 (DEV_QUERY_REG0 + 4)
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#define DEV_QUERY_REG5 (DEV_QUERY_REG0 + 5)
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#define DEV_QUERY_REG6 (DEV_QUERY_REG0 + 6)
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#define DEV_QUERY_REG7 (DEV_QUERY_REG0 + 7)
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#define DEV_QUERY_REG8 (DEV_QUERY_REG0 + 8)
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#define GENERAL_2D_CONTROL_REG 0x1041
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#define SENSOR_SENSITIVITY_REG 0x1044
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#define SENS_MAX_POS_MSB_REG 0x1046
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#define SENS_MAX_POS_LSB_REG (SENS_MAX_POS_UPPER_REG + 1)
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/* Device Control Register Bits */
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#define REPORT_RATE_1ST_BIT 6
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/* Interrupt Enable Register Bits (INTERRUPT_EN_REG) */
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#define F10_ABS_INT_ENA 0
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#define F10_REL_INT_ENA 1
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#define F20_INT_ENA 2
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/* Interrupt Request Register Bits (INT_REQ_STAT_REG | DEVICE_STATUS_REG) */
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#define F10_ABS_INT_REQ 0
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#define F10_REL_INT_REQ 1
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#define F20_INT_REQ 2
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/* Device Status Register Bits (DEVICE_STATUS_REG) */
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#define STAT_CONFIGURED 6
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/* Device Command Register Bits (DEV_COMMAND_REG) */
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#define RESET_COMMAND 0x01
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#define REZERO_COMMAND 0x02
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/* Data Register 0 Bits (DATA_REG0) */
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/* Device Query Registers Bits */
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#define HAS_PALM_DETECT 1
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#define HAS_MULTI_FING 2
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#define HAS_SCROLLER 4
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#define HAS_2D_SCROLL 5
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/* General 2D Control Register Bits (GENERAL_2D_CONTROL_REG) */
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#define NO_DECELERATION 1
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#define REDUCE_REPORTING 3
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/* Device Control Register Masks (DEV_CONTROL_REG) */
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#define REPORT_RATE_MSK 0xc0
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#define SLEEP_MODE_MSK 0x07
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/* Device Sleep Modes */
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#define FULL_AWAKE 0x0
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#define NORMAL_OP 0x1
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#define LOW_PWR_OP 0x2
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#define VERY_LOW_PWR_OP 0x3
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#define SENS_SLEEP 0x4
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#define SLEEP_MOD 0x5
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#define DEEP_SLEEP 0x6
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#define HIBERNATE 0x7
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/* Interrupt Register Mask */
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/* (INT_REQ_STAT_REG | DEVICE_STATUS_REG | INTERRUPT_EN_REG) */
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#define INT_ENA_REQ_MSK 0x07
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#define INT_ENA_ABS_MSK 0x01
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#define INT_ENA_REL_MSK 0x02
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#define INT_ENA_F20_MSK 0x04
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/* Device Status Register Masks (DEVICE_STATUS_REG) */
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#define CONFIGURED_MSK 0x40
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#define ERROR_MSK 0x80
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/* Data Register 0 Masks */
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#define FINGER_WIDTH_MSK 0xf0
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#define GESTURE_MSK 0x08
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#define SENSOR_STATUS_MSK 0x07
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* MSB Position Register Masks
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* ABS_MSB_X_REG | ABS_MSB_Y_REG | SENS_MAX_POS_MSB_REG |
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* DEV_QUERY_REG3 | DEV_QUERY_REG5
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#define MSB_POSITION_MSK 0x1f
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/* Device Query Registers Masks */
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#define NUM_EXTRA_POS_MSK 0x07
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/* When in IRQ mode read the device every THREAD_IRQ_SLEEP_SECS */
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#define THREAD_IRQ_SLEEP_SECS 2
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#define THREAD_IRQ_SLEEP_MSECS (THREAD_IRQ_SLEEP_SECS * MSEC_PER_SEC)
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* When in Polling mode and no data received for NO_DATA_THRES msecs
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* reduce the polling rate to NO_DATA_SLEEP_MSECS
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#define NO_DATA_THRES (MSEC_PER_SEC)
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#define NO_DATA_SLEEP_MSECS (MSEC_PER_SEC / 4)
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/* Control touchpad's No Deceleration option */
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static int no_decel = 1;
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module_param(no_decel, bool, 0644);
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MODULE_PARM_DESC(no_decel, "No Deceleration. Default = 1 (on)");
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/* Control touchpad's Reduced Reporting option */
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static int reduce_report;
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module_param(reduce_report, bool, 0644);
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MODULE_PARM_DESC(reduce_report, "Reduced Reporting. Default = 0 (off)");
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/* Control touchpad's No Filter option */
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static int no_filter;
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module_param(no_filter, bool, 0644);
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MODULE_PARM_DESC(no_filter, "No Filter. Default = 0 (off)");
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* touchpad Attention line is Active Low and Open Drain,
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* therefore should be connected to pulled up line
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* and the irq configuration should be set to Falling Edge Trigger
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/* Control IRQ / Polling option */
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static bool polling_req;
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module_param(polling_req, bool, 0444);
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MODULE_PARM_DESC(polling_req, "Request Polling. Default = 0 (use irq)");
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/* Control Polling Rate */
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static int scan_rate = 80;
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module_param(scan_rate, int, 0644);
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MODULE_PARM_DESC(scan_rate, "Polling rate in times/sec. Default = 80");
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/* The main device structure */
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struct synaptics_i2c {
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struct i2c_client *client;
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struct input_dev *input;
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struct delayed_work dwork;
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int reduce_report_param;
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static inline void set_scan_rate(struct synaptics_i2c *touch, int scan_rate)
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touch->scan_ms = MSEC_PER_SEC / scan_rate;
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touch->scan_rate_param = scan_rate;
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* Driver's initial design makes no race condition possible on i2c bus,
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* so there is no need in any locking.
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* Keep it in mind, while playing with the code.
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static s32 synaptics_i2c_reg_get(struct i2c_client *client, u16 reg)
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ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
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ret = i2c_smbus_read_byte_data(client, reg & 0xff);
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static s32 synaptics_i2c_reg_set(struct i2c_client *client, u16 reg, u8 val)
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ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
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ret = i2c_smbus_write_byte_data(client, reg & 0xff, val);
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static s32 synaptics_i2c_word_get(struct i2c_client *client, u16 reg)
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ret = i2c_smbus_write_byte_data(client, PAGE_SEL_REG, reg >> 8);
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ret = i2c_smbus_read_word_data(client, reg & 0xff);
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static int synaptics_i2c_config(struct i2c_client *client)
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/* set Report Rate to Device Highest (>=80) and Sleep to normal */
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ret = synaptics_i2c_reg_set(client, DEV_CONTROL_REG, 0xc1);
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/* set Interrupt Disable to Func20 / Enable to Func10) */
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int_en = (polling_req) ? 0 : INT_ENA_ABS_MSK | INT_ENA_REL_MSK;
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ret = synaptics_i2c_reg_set(client, INTERRUPT_EN_REG, int_en);
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control = synaptics_i2c_reg_get(client, GENERAL_2D_CONTROL_REG);
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/* No Deceleration */
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control |= no_decel ? 1 << NO_DECELERATION : 0;
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/* Reduced Reporting */
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control |= reduce_report ? 1 << REDUCE_REPORTING : 0;
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control |= no_filter ? 1 << NO_FILTER : 0;
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ret = synaptics_i2c_reg_set(client, GENERAL_2D_CONTROL_REG, control);
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static int synaptics_i2c_reset_config(struct i2c_client *client)
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/* Reset the Touchpad */
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ret = synaptics_i2c_reg_set(client, DEV_COMMAND_REG, RESET_COMMAND);
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dev_err(&client->dev, "Unable to reset device\n");
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msleep(SOFT_RESET_DELAY_MS);
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ret = synaptics_i2c_config(client);
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dev_err(&client->dev, "Unable to config device\n");
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static int synaptics_i2c_check_error(struct i2c_client *client)
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status = i2c_smbus_read_byte_data(client, DEVICE_STATUS_REG) &
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(CONFIGURED_MSK | ERROR_MSK);
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if (status != CONFIGURED_MSK)
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ret = synaptics_i2c_reset_config(client);
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static bool synaptics_i2c_get_input(struct synaptics_i2c *touch)
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struct input_dev *input = touch->input;
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int xy_delta, gesture;
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/* Deal with spontanious resets and errors */
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if (synaptics_i2c_check_error(touch->client))
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/* Get Gesture Bit */
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data = synaptics_i2c_reg_get(touch->client, DATA_REG0);
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gesture = (data >> GESTURE) & 0x1;
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* Get Relative axes. we have to get them in one shot,
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* so we get 2 bytes starting from REL_X_REG.
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xy_delta = synaptics_i2c_word_get(touch->client, REL_X_REG) & 0xffff;
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/* Separate X from Y */
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x_delta = xy_delta & 0xff;
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y_delta = (xy_delta >> REGISTER_LENGTH) & 0xff;
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/* Report the button event */
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input_report_key(input, BTN_LEFT, gesture);
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/* Report the deltas */
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input_report_rel(input, REL_X, x_delta);
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input_report_rel(input, REL_Y, -y_delta);
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return xy_delta || gesture;
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static void synaptics_i2c_reschedule_work(struct synaptics_i2c *touch,
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spin_lock_irqsave(&touch->lock, flags);
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* If work is already scheduled then subsequent schedules will not
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* change the scheduled time that's why we have to cancel it first.
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__cancel_delayed_work(&touch->dwork);
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schedule_delayed_work(&touch->dwork, delay);
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spin_unlock_irqrestore(&touch->lock, flags);
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static irqreturn_t synaptics_i2c_irq(int irq, void *dev_id)
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struct synaptics_i2c *touch = dev_id;
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synaptics_i2c_reschedule_work(touch, 0);
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static void synaptics_i2c_check_params(struct synaptics_i2c *touch)
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if (scan_rate != touch->scan_rate_param)
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set_scan_rate(touch, scan_rate);
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if (no_decel != touch->no_decel_param) {
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touch->no_decel_param = no_decel;
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if (no_filter != touch->no_filter_param) {
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touch->no_filter_param = no_filter;
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if (reduce_report != touch->reduce_report_param) {
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touch->reduce_report_param = reduce_report;
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synaptics_i2c_reset_config(touch->client);
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/* Control the Device polling rate / Work Handler sleep time */
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static unsigned long synaptics_i2c_adjust_delay(struct synaptics_i2c *touch,
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unsigned long delay, nodata_count_thres;
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delay = touch->scan_ms;
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touch->no_data_count = 0;
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nodata_count_thres = NO_DATA_THRES / touch->scan_ms;
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if (touch->no_data_count < nodata_count_thres)
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touch->no_data_count++;
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delay = NO_DATA_SLEEP_MSECS;
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return msecs_to_jiffies(delay);
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delay = msecs_to_jiffies(THREAD_IRQ_SLEEP_MSECS);
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return round_jiffies_relative(delay);
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static void synaptics_i2c_work_handler(struct work_struct *work)
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struct synaptics_i2c *touch =
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container_of(work, struct synaptics_i2c, dwork.work);
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synaptics_i2c_check_params(touch);
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have_data = synaptics_i2c_get_input(touch);
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delay = synaptics_i2c_adjust_delay(touch, have_data);
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* While interrupt driven, there is no real need to poll the device.
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* But touchpads are very sensitive, so there could be errors
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* related to physical environment and the attention line isn't
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* necessarily asserted. In such case we can lose the touchpad.
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* We poll the device once in THREAD_IRQ_SLEEP_SECS and
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* if error is detected, we try to reset and reconfigure the touchpad.
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synaptics_i2c_reschedule_work(touch, delay);
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static int synaptics_i2c_open(struct input_dev *input)
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struct synaptics_i2c *touch = input_get_drvdata(input);
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ret = synaptics_i2c_reset_config(touch->client);
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synaptics_i2c_reschedule_work(touch,
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msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
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static void synaptics_i2c_close(struct input_dev *input)
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struct synaptics_i2c *touch = input_get_drvdata(input);
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synaptics_i2c_reg_set(touch->client, INTERRUPT_EN_REG, 0);
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cancel_delayed_work_sync(&touch->dwork);
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/* Save some power */
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synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
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static void synaptics_i2c_set_input_params(struct synaptics_i2c *touch)
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struct input_dev *input = touch->input;
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input->name = touch->client->name;
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input->phys = touch->client->adapter->name;
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input->id.bustype = BUS_I2C;
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input->id.version = synaptics_i2c_word_get(touch->client,
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input->dev.parent = &touch->client->dev;
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input->open = synaptics_i2c_open;
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input->close = synaptics_i2c_close;
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input_set_drvdata(input, touch);
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/* Register the device as mouse */
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__set_bit(EV_REL, input->evbit);
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__set_bit(REL_X, input->relbit);
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__set_bit(REL_Y, input->relbit);
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/* Register device's buttons and keys */
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__set_bit(EV_KEY, input->evbit);
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__set_bit(BTN_LEFT, input->keybit);
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static struct synaptics_i2c *synaptics_i2c_touch_create(struct i2c_client *client)
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struct synaptics_i2c *touch;
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touch = kzalloc(sizeof(struct synaptics_i2c), GFP_KERNEL);
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touch->client = client;
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touch->no_decel_param = no_decel;
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touch->scan_rate_param = scan_rate;
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set_scan_rate(touch, scan_rate);
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INIT_DELAYED_WORK(&touch->dwork, synaptics_i2c_work_handler);
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spin_lock_init(&touch->lock);
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static int __devinit synaptics_i2c_probe(struct i2c_client *client,
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const struct i2c_device_id *dev_id)
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struct synaptics_i2c *touch;
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touch = synaptics_i2c_touch_create(client);
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ret = synaptics_i2c_reset_config(client);
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touch->input = input_allocate_device();
566
synaptics_i2c_set_input_params(touch);
569
dev_dbg(&touch->client->dev,
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"Requesting IRQ: %d\n", touch->client->irq);
572
ret = request_irq(touch->client->irq, synaptics_i2c_irq,
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IRQ_TYPE_EDGE_FALLING,
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dev_warn(&touch->client->dev,
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"IRQ request failed: %d, "
578
"falling back to polling\n", ret);
580
synaptics_i2c_reg_set(touch->client,
581
INTERRUPT_EN_REG, 0);
586
dev_dbg(&touch->client->dev,
587
"Using polling at rate: %d times/sec\n", scan_rate);
589
/* Register the device in input subsystem */
590
ret = input_register_device(touch->input);
592
dev_err(&client->dev,
593
"Input device register failed: %d\n", ret);
597
i2c_set_clientdata(client, touch);
602
input_free_device(touch->input);
609
static int __devexit synaptics_i2c_remove(struct i2c_client *client)
611
struct synaptics_i2c *touch = i2c_get_clientdata(client);
614
free_irq(client->irq, touch);
616
input_unregister_device(touch->input);
622
#ifdef CONFIG_PM_SLEEP
623
static int synaptics_i2c_suspend(struct device *dev)
625
struct i2c_client *client = to_i2c_client(dev);
626
struct synaptics_i2c *touch = i2c_get_clientdata(client);
628
cancel_delayed_work_sync(&touch->dwork);
630
/* Save some power */
631
synaptics_i2c_reg_set(touch->client, DEV_CONTROL_REG, DEEP_SLEEP);
636
static int synaptics_i2c_resume(struct device *dev)
639
struct i2c_client *client = to_i2c_client(dev);
640
struct synaptics_i2c *touch = i2c_get_clientdata(client);
642
ret = synaptics_i2c_reset_config(client);
646
synaptics_i2c_reschedule_work(touch,
647
msecs_to_jiffies(NO_DATA_SLEEP_MSECS));
653
static SIMPLE_DEV_PM_OPS(synaptics_i2c_pm, synaptics_i2c_suspend,
654
synaptics_i2c_resume);
656
static const struct i2c_device_id synaptics_i2c_id_table[] = {
657
{ "synaptics_i2c", 0 },
660
MODULE_DEVICE_TABLE(i2c, synaptics_i2c_id_table);
662
static struct i2c_driver synaptics_i2c_driver = {
665
.owner = THIS_MODULE,
666
.pm = &synaptics_i2c_pm,
669
.probe = synaptics_i2c_probe,
670
.remove = __devexit_p(synaptics_i2c_remove),
672
.id_table = synaptics_i2c_id_table,
675
static int __init synaptics_i2c_init(void)
677
return i2c_add_driver(&synaptics_i2c_driver);
680
static void __exit synaptics_i2c_exit(void)
682
i2c_del_driver(&synaptics_i2c_driver);
685
module_init(synaptics_i2c_init);
686
module_exit(synaptics_i2c_exit);
688
MODULE_DESCRIPTION("Synaptics I2C touchpad driver");
689
MODULE_AUTHOR("Mike Rapoport, Igor Grinberg, Compulab");
690
MODULE_LICENSE("GPL");