/* * Input driver for Microchip CAP11xx based capacitive touch sensors * * (c) 2014 Daniel Mack * * 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 #include #include #include #include #include #include #include #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 "); MODULE_LICENSE("GPL v2");