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