diff options
Diffstat (limited to 'drivers/input/keyboard/cap1106.c')
| -rw-r--r-- | drivers/input/keyboard/cap1106.c | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/drivers/input/keyboard/cap1106.c b/drivers/input/keyboard/cap1106.c new file mode 100644 index 000000000000..f7d7a0d4ab4e --- /dev/null +++ b/drivers/input/keyboard/cap1106.c @@ -0,0 +1,335 @@ +/* + * Input driver for Microchip CAP1106, 6 channel capacitive touch sensor + * + * http://www.microchip.com/wwwproducts/Devices.aspx?product=CAP1106 + * + * (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 CAP1106_REG_MAIN_CONTROL 0x00 +#define CAP1106_REG_MAIN_CONTROL_GAIN_SHIFT (6) +#define CAP1106_REG_MAIN_CONTROL_GAIN_MASK (0xc0) +#define CAP1106_REG_MAIN_CONTROL_DLSEEP BIT(4) +#define CAP1106_REG_GENERAL_STATUS 0x02 +#define CAP1106_REG_SENSOR_INPUT 0x03 +#define CAP1106_REG_NOISE_FLAG_STATUS 0x0a +#define CAP1106_REG_SENOR_DELTA(X) (0x10 + (X)) +#define CAP1106_REG_SENSITIVITY_CONTROL 0x1f +#define CAP1106_REG_CONFIG 0x20 +#define CAP1106_REG_SENSOR_ENABLE 0x21 +#define CAP1106_REG_SENSOR_CONFIG 0x22 +#define CAP1106_REG_SENSOR_CONFIG2 0x23 +#define CAP1106_REG_SAMPLING_CONFIG 0x24 +#define CAP1106_REG_CALIBRATION 0x25 +#define CAP1106_REG_INT_ENABLE 0x26 +#define CAP1106_REG_REPEAT_RATE 0x28 +#define CAP1106_REG_MT_CONFIG 0x2a +#define CAP1106_REG_MT_PATTERN_CONFIG 0x2b +#define CAP1106_REG_MT_PATTERN 0x2d +#define CAP1106_REG_RECALIB_CONFIG 0x2f +#define CAP1106_REG_SENSOR_THRESH(X) (0x30 + (X)) +#define CAP1106_REG_SENSOR_NOISE_THRESH 0x38 +#define CAP1106_REG_STANDBY_CHANNEL 0x40 +#define CAP1106_REG_STANDBY_CONFIG 0x41 +#define CAP1106_REG_STANDBY_SENSITIVITY 0x42 +#define CAP1106_REG_STANDBY_THRESH 0x43 +#define CAP1106_REG_CONFIG2 0x44 +#define CAP1106_REG_SENSOR_BASE_CNT(X) (0x50 + (X)) +#define CAP1106_REG_SENSOR_CALIB (0xb1 + (X)) +#define CAP1106_REG_SENSOR_CALIB_LSB1 0xb9 +#define CAP1106_REG_SENSOR_CALIB_LSB2 0xba +#define CAP1106_REG_PRODUCT_ID 0xfd +#define CAP1106_REG_MANUFACTURER_ID 0xfe +#define CAP1106_REG_REVISION 0xff + +#define CAP1106_NUM_CHN 6 +#define CAP1106_PRODUCT_ID 0x55 +#define CAP1106_MANUFACTURER_ID 0x5d + +struct cap1106_priv { + struct regmap *regmap; + struct input_dev *idev; + + /* config */ + unsigned int keycodes[CAP1106_NUM_CHN]; +}; + +static const struct reg_default cap1106_reg_defaults[] = { + { CAP1106_REG_MAIN_CONTROL, 0x00 }, + { CAP1106_REG_GENERAL_STATUS, 0x00 }, + { CAP1106_REG_SENSOR_INPUT, 0x00 }, + { CAP1106_REG_NOISE_FLAG_STATUS, 0x00 }, + { CAP1106_REG_SENSITIVITY_CONTROL, 0x2f }, + { CAP1106_REG_CONFIG, 0x20 }, + { CAP1106_REG_SENSOR_ENABLE, 0x3f }, + { CAP1106_REG_SENSOR_CONFIG, 0xa4 }, + { CAP1106_REG_SENSOR_CONFIG2, 0x07 }, + { CAP1106_REG_SAMPLING_CONFIG, 0x39 }, + { CAP1106_REG_CALIBRATION, 0x00 }, + { CAP1106_REG_INT_ENABLE, 0x3f }, + { CAP1106_REG_REPEAT_RATE, 0x3f }, + { CAP1106_REG_MT_CONFIG, 0x80 }, + { CAP1106_REG_MT_PATTERN_CONFIG, 0x00 }, + { CAP1106_REG_MT_PATTERN, 0x3f }, + { CAP1106_REG_RECALIB_CONFIG, 0x8a }, + { CAP1106_REG_SENSOR_THRESH(0), 0x40 }, + { CAP1106_REG_SENSOR_THRESH(1), 0x40 }, + { CAP1106_REG_SENSOR_THRESH(2), 0x40 }, + { CAP1106_REG_SENSOR_THRESH(3), 0x40 }, + { CAP1106_REG_SENSOR_THRESH(4), 0x40 }, + { CAP1106_REG_SENSOR_THRESH(5), 0x40 }, + { CAP1106_REG_SENSOR_NOISE_THRESH, 0x01 }, + { CAP1106_REG_STANDBY_CHANNEL, 0x00 }, + { CAP1106_REG_STANDBY_CONFIG, 0x39 }, + { CAP1106_REG_STANDBY_SENSITIVITY, 0x02 }, + { CAP1106_REG_STANDBY_THRESH, 0x40 }, + { CAP1106_REG_CONFIG2, 0x40 }, + { CAP1106_REG_SENSOR_CALIB_LSB1, 0x00 }, + { CAP1106_REG_SENSOR_CALIB_LSB2, 0x00 }, +}; + +static bool cap1106_volatile_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case CAP1106_REG_MAIN_CONTROL: + case CAP1106_REG_SENSOR_INPUT: + case CAP1106_REG_SENOR_DELTA(0): + case CAP1106_REG_SENOR_DELTA(1): + case CAP1106_REG_SENOR_DELTA(2): + case CAP1106_REG_SENOR_DELTA(3): + case CAP1106_REG_SENOR_DELTA(4): + case CAP1106_REG_SENOR_DELTA(5): + case CAP1106_REG_PRODUCT_ID: + case CAP1106_REG_MANUFACTURER_ID: + case CAP1106_REG_REVISION: + return true; + } + + return false; +} + +static const struct regmap_config cap1106_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + + .max_register = CAP1106_REG_REVISION, + .reg_defaults = cap1106_reg_defaults, + + .num_reg_defaults = ARRAY_SIZE(cap1106_reg_defaults), + .cache_type = REGCACHE_RBTREE, + .volatile_reg = cap1106_volatile_reg, +}; + +static irqreturn_t cap1106_thread_func(int irq_num, void *data) +{ + struct cap1106_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, CAP1106_REG_MAIN_CONTROL, 1, 0); + if (ret < 0) + goto out; + + ret = regmap_read(priv->regmap, CAP1106_REG_SENSOR_INPUT, &status); + if (ret < 0) + goto out; + + for (i = 0; i < CAP1106_NUM_CHN; i++) + input_report_key(priv->idev, priv->keycodes[i], + status & (1 << i)); + + input_sync(priv->idev); + +out: + return IRQ_HANDLED; +} + +static int cap1106_set_sleep(struct cap1106_priv *priv, bool sleep) +{ + return regmap_update_bits(priv->regmap, CAP1106_REG_MAIN_CONTROL, + CAP1106_REG_MAIN_CONTROL_DLSEEP, + sleep ? CAP1106_REG_MAIN_CONTROL_DLSEEP : 0); +} + +static int cap1106_input_open(struct input_dev *idev) +{ + struct cap1106_priv *priv = input_get_drvdata(idev); + + return cap1106_set_sleep(priv, false); +} + +static void cap1106_input_close(struct input_dev *idev) +{ + struct cap1106_priv *priv = input_get_drvdata(idev); + + cap1106_set_sleep(priv, true); +} + +static int cap1106_i2c_probe(struct i2c_client *i2c_client, + const struct i2c_device_id *id) +{ + struct device *dev = &i2c_client->dev; + struct cap1106_priv *priv; + struct device_node *node; + int i, error, irq, gain = 0; + unsigned int val, rev; + u32 gain32, keycodes[CAP1106_NUM_CHN]; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->regmap = devm_regmap_init_i2c(i2c_client, &cap1106_regmap_config); + if (IS_ERR(priv->regmap)) + return PTR_ERR(priv->regmap); + + error = regmap_read(priv->regmap, CAP1106_REG_PRODUCT_ID, &val); + if (error) + return error; + + if (val != CAP1106_PRODUCT_ID) { + dev_err(dev, "Product ID: Got 0x%02x, expected 0x%02x\n", + val, CAP1106_PRODUCT_ID); + return -ENODEV; + } + + error = regmap_read(priv->regmap, CAP1106_REG_MANUFACTURER_ID, &val); + if (error) + return error; + + if (val != CAP1106_MANUFACTURER_ID) { + dev_err(dev, "Manufacturer ID: Got 0x%02x, expected 0x%02x\n", + val, CAP1106_MANUFACTURER_ID); + return -ENODEV; + } + + error = regmap_read(priv->regmap, CAP1106_REG_REVISION, &rev); + if (error < 0) + return error; + + dev_info(dev, "CAP1106 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); + } + + BUILD_BUG_ON(ARRAY_SIZE(keycodes) != ARRAY_SIZE(priv->keycodes)); + + /* Provide some useful defaults */ + for (i = 0; i < ARRAY_SIZE(keycodes); i++) + keycodes[i] = KEY_A + i; + + of_property_read_u32_array(node, "linux,keycodes", + keycodes, ARRAY_SIZE(keycodes)); + + for (i = 0; i < ARRAY_SIZE(keycodes); i++) + priv->keycodes[i] = keycodes[i]; + + error = regmap_update_bits(priv->regmap, CAP1106_REG_MAIN_CONTROL, + CAP1106_REG_MAIN_CONTROL_GAIN_MASK, + gain << CAP1106_REG_MAIN_CONTROL_GAIN_SHIFT); + if (error) + return error; + + /* Disable autorepeat. The Linux input system has its own handling. */ + error = regmap_write(priv->regmap, CAP1106_REG_REPEAT_RATE, 0); + if (error) + return error; + + priv->idev = devm_input_allocate_device(dev); + if (!priv->idev) + return -ENOMEM; + + priv->idev->name = "CAP1106 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 < CAP1106_NUM_CHN; i++) + __set_bit(priv->keycodes[i], priv->idev->keybit); + + priv->idev->id.vendor = CAP1106_MANUFACTURER_ID; + priv->idev->id.product = CAP1106_PRODUCT_ID; + priv->idev->id.version = rev; + + priv->idev->open = cap1106_input_open; + priv->idev->close = cap1106_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. + */ + cap1106_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, cap1106_thread_func, + IRQF_ONESHOT, dev_name(dev), priv); + if (error) + return error; + + return 0; +} + +static const struct of_device_id cap1106_dt_ids[] = { + { .compatible = "microchip,cap1106", }, + {} +}; +MODULE_DEVICE_TABLE(of, cap1106_dt_ids); + +static const struct i2c_device_id cap1106_i2c_ids[] = { + { "cap1106", 0 }, + {} +}; +MODULE_DEVICE_TABLE(i2c, cap1106_i2c_ids); + +static struct i2c_driver cap1106_i2c_driver = { + .driver = { + .name = "cap1106", + .owner = THIS_MODULE, + .of_match_table = cap1106_dt_ids, + }, + .id_table = cap1106_i2c_ids, + .probe = cap1106_i2c_probe, +}; + +module_i2c_driver(cap1106_i2c_driver); + +MODULE_ALIAS("platform:cap1106"); +MODULE_DESCRIPTION("Microchip CAP1106 driver"); +MODULE_AUTHOR("Daniel Mack <linux@zonque.org>"); +MODULE_LICENSE("GPL v2"); |