376 lines
10 KiB
C
376 lines
10 KiB
C
/*
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* Input driver for Microchip CAP11xx based capacitive touch sensors
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*
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* (c) 2014 Daniel Mack <linux@zonque.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/input.h>
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#include <linux/of_irq.h>
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#include <linux/regmap.h>
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#include <linux/i2c.h>
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#include <linux/gpio/consumer.h>
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#define CAP11XX_REG_MAIN_CONTROL 0x00
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#define CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT (6)
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#define CAP11XX_REG_MAIN_CONTROL_GAIN_MASK (0xc0)
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#define CAP11XX_REG_MAIN_CONTROL_DLSEEP BIT(4)
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#define CAP11XX_REG_GENERAL_STATUS 0x02
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#define CAP11XX_REG_SENSOR_INPUT 0x03
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#define CAP11XX_REG_NOISE_FLAG_STATUS 0x0a
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#define CAP11XX_REG_SENOR_DELTA(X) (0x10 + (X))
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#define CAP11XX_REG_SENSITIVITY_CONTROL 0x1f
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#define CAP11XX_REG_CONFIG 0x20
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#define CAP11XX_REG_SENSOR_ENABLE 0x21
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#define CAP11XX_REG_SENSOR_CONFIG 0x22
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#define CAP11XX_REG_SENSOR_CONFIG2 0x23
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#define CAP11XX_REG_SAMPLING_CONFIG 0x24
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#define CAP11XX_REG_CALIBRATION 0x26
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#define CAP11XX_REG_INT_ENABLE 0x27
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#define CAP11XX_REG_REPEAT_RATE 0x28
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#define CAP11XX_REG_MT_CONFIG 0x2a
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#define CAP11XX_REG_MT_PATTERN_CONFIG 0x2b
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#define CAP11XX_REG_MT_PATTERN 0x2d
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#define CAP11XX_REG_RECALIB_CONFIG 0x2f
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#define CAP11XX_REG_SENSOR_THRESH(X) (0x30 + (X))
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#define CAP11XX_REG_SENSOR_NOISE_THRESH 0x38
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#define CAP11XX_REG_STANDBY_CHANNEL 0x40
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#define CAP11XX_REG_STANDBY_CONFIG 0x41
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#define CAP11XX_REG_STANDBY_SENSITIVITY 0x42
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#define CAP11XX_REG_STANDBY_THRESH 0x43
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#define CAP11XX_REG_CONFIG2 0x44
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#define CAP11XX_REG_CONFIG2_ALT_POL BIT(6)
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#define CAP11XX_REG_SENSOR_BASE_CNT(X) (0x50 + (X))
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#define CAP11XX_REG_SENSOR_CALIB (0xb1 + (X))
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#define CAP11XX_REG_SENSOR_CALIB_LSB1 0xb9
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#define CAP11XX_REG_SENSOR_CALIB_LSB2 0xba
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#define CAP11XX_REG_PRODUCT_ID 0xfd
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#define CAP11XX_REG_MANUFACTURER_ID 0xfe
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#define CAP11XX_REG_REVISION 0xff
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#define CAP11XX_MANUFACTURER_ID 0x5d
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struct cap11xx_priv {
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struct regmap *regmap;
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struct input_dev *idev;
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/* config */
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u32 keycodes[];
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};
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struct cap11xx_hw_model {
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u8 product_id;
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unsigned int num_channels;
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};
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enum {
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CAP1106,
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CAP1126,
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CAP1188,
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};
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static const struct cap11xx_hw_model cap11xx_devices[] = {
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[CAP1106] = { .product_id = 0x55, .num_channels = 6 },
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[CAP1126] = { .product_id = 0x53, .num_channels = 6 },
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[CAP1188] = { .product_id = 0x50, .num_channels = 8 },
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};
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static const struct reg_default cap11xx_reg_defaults[] = {
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{ CAP11XX_REG_MAIN_CONTROL, 0x00 },
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{ CAP11XX_REG_GENERAL_STATUS, 0x00 },
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{ CAP11XX_REG_SENSOR_INPUT, 0x00 },
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{ CAP11XX_REG_NOISE_FLAG_STATUS, 0x00 },
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{ CAP11XX_REG_SENSITIVITY_CONTROL, 0x2f },
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{ CAP11XX_REG_CONFIG, 0x20 },
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{ CAP11XX_REG_SENSOR_ENABLE, 0x3f },
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{ CAP11XX_REG_SENSOR_CONFIG, 0xa4 },
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{ CAP11XX_REG_SENSOR_CONFIG2, 0x07 },
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{ CAP11XX_REG_SAMPLING_CONFIG, 0x39 },
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{ CAP11XX_REG_CALIBRATION, 0x00 },
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{ CAP11XX_REG_INT_ENABLE, 0x3f },
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{ CAP11XX_REG_REPEAT_RATE, 0x3f },
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{ CAP11XX_REG_MT_CONFIG, 0x80 },
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{ CAP11XX_REG_MT_PATTERN_CONFIG, 0x00 },
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{ CAP11XX_REG_MT_PATTERN, 0x3f },
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{ CAP11XX_REG_RECALIB_CONFIG, 0x8a },
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{ CAP11XX_REG_SENSOR_THRESH(0), 0x40 },
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{ CAP11XX_REG_SENSOR_THRESH(1), 0x40 },
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{ CAP11XX_REG_SENSOR_THRESH(2), 0x40 },
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{ CAP11XX_REG_SENSOR_THRESH(3), 0x40 },
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{ CAP11XX_REG_SENSOR_THRESH(4), 0x40 },
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{ CAP11XX_REG_SENSOR_THRESH(5), 0x40 },
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{ CAP11XX_REG_SENSOR_NOISE_THRESH, 0x01 },
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{ CAP11XX_REG_STANDBY_CHANNEL, 0x00 },
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{ CAP11XX_REG_STANDBY_CONFIG, 0x39 },
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{ CAP11XX_REG_STANDBY_SENSITIVITY, 0x02 },
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{ CAP11XX_REG_STANDBY_THRESH, 0x40 },
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{ CAP11XX_REG_CONFIG2, 0x40 },
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{ CAP11XX_REG_SENSOR_CALIB_LSB1, 0x00 },
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{ CAP11XX_REG_SENSOR_CALIB_LSB2, 0x00 },
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};
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static bool cap11xx_volatile_reg(struct device *dev, unsigned int reg)
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{
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switch (reg) {
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case CAP11XX_REG_MAIN_CONTROL:
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case CAP11XX_REG_SENSOR_INPUT:
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case CAP11XX_REG_SENOR_DELTA(0):
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case CAP11XX_REG_SENOR_DELTA(1):
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case CAP11XX_REG_SENOR_DELTA(2):
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case CAP11XX_REG_SENOR_DELTA(3):
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case CAP11XX_REG_SENOR_DELTA(4):
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case CAP11XX_REG_SENOR_DELTA(5):
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case CAP11XX_REG_PRODUCT_ID:
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case CAP11XX_REG_MANUFACTURER_ID:
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case CAP11XX_REG_REVISION:
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return true;
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}
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return false;
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}
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static const struct regmap_config cap11xx_regmap_config = {
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.reg_bits = 8,
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.val_bits = 8,
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.max_register = CAP11XX_REG_REVISION,
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.reg_defaults = cap11xx_reg_defaults,
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.num_reg_defaults = ARRAY_SIZE(cap11xx_reg_defaults),
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.cache_type = REGCACHE_RBTREE,
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.volatile_reg = cap11xx_volatile_reg,
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};
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static irqreturn_t cap11xx_thread_func(int irq_num, void *data)
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{
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struct cap11xx_priv *priv = data;
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unsigned int status;
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int ret, i;
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/*
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* Deassert interrupt. This needs to be done before reading the status
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* registers, which will not carry valid values otherwise.
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*/
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ret = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 1, 0);
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if (ret < 0)
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goto out;
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ret = regmap_read(priv->regmap, CAP11XX_REG_SENSOR_INPUT, &status);
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if (ret < 0)
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goto out;
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for (i = 0; i < priv->idev->keycodemax; i++)
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input_report_key(priv->idev, priv->keycodes[i],
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status & (1 << i));
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input_sync(priv->idev);
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out:
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return IRQ_HANDLED;
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}
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static int cap11xx_set_sleep(struct cap11xx_priv *priv, bool sleep)
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{
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return regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL,
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CAP11XX_REG_MAIN_CONTROL_DLSEEP,
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sleep ? CAP11XX_REG_MAIN_CONTROL_DLSEEP : 0);
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}
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static int cap11xx_input_open(struct input_dev *idev)
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{
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struct cap11xx_priv *priv = input_get_drvdata(idev);
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return cap11xx_set_sleep(priv, false);
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}
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static void cap11xx_input_close(struct input_dev *idev)
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{
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struct cap11xx_priv *priv = input_get_drvdata(idev);
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cap11xx_set_sleep(priv, true);
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}
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static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
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const struct i2c_device_id *id)
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{
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struct device *dev = &i2c_client->dev;
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struct cap11xx_priv *priv;
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struct device_node *node;
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const struct cap11xx_hw_model *cap;
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int i, error, irq, gain = 0;
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unsigned int val, rev;
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u32 gain32;
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if (id->driver_data >= ARRAY_SIZE(cap11xx_devices)) {
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dev_err(dev, "Invalid device ID %lu\n", id->driver_data);
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return -EINVAL;
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}
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cap = &cap11xx_devices[id->driver_data];
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if (!cap || !cap->num_channels) {
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dev_err(dev, "Invalid device configuration\n");
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return -EINVAL;
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}
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priv = devm_kzalloc(dev,
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sizeof(*priv) +
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cap->num_channels * sizeof(priv->keycodes[0]),
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GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->regmap = devm_regmap_init_i2c(i2c_client, &cap11xx_regmap_config);
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if (IS_ERR(priv->regmap))
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return PTR_ERR(priv->regmap);
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error = regmap_read(priv->regmap, CAP11XX_REG_PRODUCT_ID, &val);
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if (error)
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return error;
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if (val != cap->product_id) {
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dev_err(dev, "Product ID: Got 0x%02x, expected 0x%02x\n",
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val, cap->product_id);
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return -ENXIO;
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}
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error = regmap_read(priv->regmap, CAP11XX_REG_MANUFACTURER_ID, &val);
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if (error)
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return error;
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if (val != CAP11XX_MANUFACTURER_ID) {
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dev_err(dev, "Manufacturer ID: Got 0x%02x, expected 0x%02x\n",
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val, CAP11XX_MANUFACTURER_ID);
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return -ENXIO;
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}
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error = regmap_read(priv->regmap, CAP11XX_REG_REVISION, &rev);
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if (error < 0)
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return error;
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dev_info(dev, "CAP11XX detected, revision 0x%02x\n", rev);
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i2c_set_clientdata(i2c_client, priv);
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node = dev->of_node;
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if (!of_property_read_u32(node, "microchip,sensor-gain", &gain32)) {
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if (is_power_of_2(gain32) && gain32 <= 8)
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gain = ilog2(gain32);
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else
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dev_err(dev, "Invalid sensor-gain value %d\n", gain32);
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}
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if (of_property_read_bool(node, "microchip,irq-active-high")) {
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error = regmap_update_bits(priv->regmap, CAP11XX_REG_CONFIG2,
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CAP11XX_REG_CONFIG2_ALT_POL, 0);
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if (error)
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return error;
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}
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/* Provide some useful defaults */
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for (i = 0; i < cap->num_channels; i++)
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priv->keycodes[i] = KEY_A + i;
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of_property_read_u32_array(node, "linux,keycodes",
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priv->keycodes, cap->num_channels);
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error = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL,
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CAP11XX_REG_MAIN_CONTROL_GAIN_MASK,
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gain << CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT);
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if (error)
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return error;
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/* Disable autorepeat. The Linux input system has its own handling. */
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error = regmap_write(priv->regmap, CAP11XX_REG_REPEAT_RATE, 0);
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if (error)
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return error;
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priv->idev = devm_input_allocate_device(dev);
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if (!priv->idev)
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return -ENOMEM;
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priv->idev->name = "CAP11XX capacitive touch sensor";
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priv->idev->id.bustype = BUS_I2C;
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priv->idev->evbit[0] = BIT_MASK(EV_KEY);
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if (of_property_read_bool(node, "autorepeat"))
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__set_bit(EV_REP, priv->idev->evbit);
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for (i = 0; i < cap->num_channels; i++)
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__set_bit(priv->keycodes[i], priv->idev->keybit);
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__clear_bit(KEY_RESERVED, priv->idev->keybit);
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priv->idev->keycode = priv->keycodes;
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priv->idev->keycodesize = sizeof(priv->keycodes[0]);
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priv->idev->keycodemax = cap->num_channels;
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priv->idev->id.vendor = CAP11XX_MANUFACTURER_ID;
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priv->idev->id.product = cap->product_id;
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priv->idev->id.version = rev;
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priv->idev->open = cap11xx_input_open;
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priv->idev->close = cap11xx_input_close;
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input_set_drvdata(priv->idev, priv);
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/*
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* Put the device in deep sleep mode for now.
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* ->open() will bring it back once the it is actually needed.
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*/
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cap11xx_set_sleep(priv, true);
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error = input_register_device(priv->idev);
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if (error)
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return error;
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irq = irq_of_parse_and_map(node, 0);
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if (!irq) {
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dev_err(dev, "Unable to parse or map IRQ\n");
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return -ENXIO;
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}
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error = devm_request_threaded_irq(dev, irq, NULL, cap11xx_thread_func,
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IRQF_ONESHOT, dev_name(dev), priv);
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if (error)
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return error;
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return 0;
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}
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static const struct of_device_id cap11xx_dt_ids[] = {
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{ .compatible = "microchip,cap1106", },
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{ .compatible = "microchip,cap1126", },
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{ .compatible = "microchip,cap1188", },
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{}
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};
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MODULE_DEVICE_TABLE(of, cap11xx_dt_ids);
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static const struct i2c_device_id cap11xx_i2c_ids[] = {
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{ "cap1106", CAP1106 },
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{ "cap1126", CAP1126 },
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{ "cap1188", CAP1188 },
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{}
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};
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MODULE_DEVICE_TABLE(i2c, cap11xx_i2c_ids);
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static struct i2c_driver cap11xx_i2c_driver = {
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.driver = {
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.name = "cap11xx",
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.owner = THIS_MODULE,
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.of_match_table = cap11xx_dt_ids,
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},
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.id_table = cap11xx_i2c_ids,
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.probe = cap11xx_i2c_probe,
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};
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module_i2c_driver(cap11xx_i2c_driver);
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MODULE_DESCRIPTION("Microchip CAP11XX driver");
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MODULE_AUTHOR("Daniel Mack <linux@zonque.org>");
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MODULE_LICENSE("GPL v2");
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