Hi
On Fri, Jul 11, 2014 at 9:42 AM, Daniel Mack <[email protected]> wrote:
> This patch adds a driver for Microchips CAP1106, an I2C driven, 6-channel
> capacitive touch sensor.
>
> For now, only the capacitive buttons are supported, and no specific
> settings that can be tweaked for individual channels, except for the
> device-wide sensitivity gain. The defaults seem to work just fine out of
> the box, so I'll leave configurable parameters for someone who's in need
> of them and who can actually measure the impact. All registers are
> prepared, however. Many of them are just not used for now.
>
> The implementation does not make any attempt to be compatible to platform
> data driven boards, but fully depends on CONFIG_OF.
>
> Power management functions are also left for volounteers with the ability
> to actually test them.
>
> Signed-off-by: Daniel Mack <[email protected]>
> ---
> .../devicetree/bindings/input/cap1106.txt | 63 ++++
> drivers/input/keyboard/Kconfig | 10 +
> drivers/input/keyboard/Makefile | 1 +
> drivers/input/keyboard/cap1106.c | 376
> +++++++++++++++++++++
> 4 files changed, 450 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/input/cap1106.txt
> create mode 100644 drivers/input/keyboard/cap1106.c
>
> diff --git a/Documentation/devicetree/bindings/input/cap1106.txt
> b/Documentation/devicetree/bindings/input/cap1106.txt
> new file mode 100644
> index 0000000..57f5af3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/cap1106.txt
> @@ -0,0 +1,63 @@
> +Device tree bindings for Microchip CAP1106, 6 channel capacitive touch sensor
> +
> +The node for this driver must be a child of a I2C controller node, as the
> +device communication via I2C only.
> +
> +Required properties:
> +
> + compatible: Must be "microchip,cap1106"
> + reg: The I2C slave address of the device.
> + Only 0x28 is valid.
> + interrupt: Node describing the interrupt line the
> device's
> + ALERT#/CM_IRQ# pin is connected to.
> +
> +Optional properties:
> +
> + autorepeat: Enables the Linux input system's autorepeat
> + feature on the input device.
> + microchip,sensor-gain: Defines the gain of the sensor circuitry. This
> + effectively controls the sensitivity, as a
> + smaller delta capacitance is required to
> + generate the same delta count values.
> + Valid values are 1, 2, 4, and 8.
> + By default, a gain of 1 is set.
> +
> +To define details of each individual button channel, six subnodes can be
> +specified. Inside each of those, the following property is valid:
> +
> + linux,keycode: Specify the numeric identifier of the keycode to be
> + generated when this channel is activated. If this
> + property is omitted, KEY_A, KEY_B, etc are used as
> + defaults.
> +
> +Example:
> +
> +i2c_controller {
> + cap1106@28 {
> + compatible = "microchip,cap1106";
> + interrupt-parent = <&gpio1>;
> + interrupts = <0 0>;
> + reg = <0x28>;
> + autorepeat;
> + microchip,sensor-gain = <2>;
> +
> + up {
> + linux,keycode = <103>; /* KEY_UP */
> + };
> + right {
> + linux,keycode = <106>; /* KEY_RIGHT */
> + };
> + down {
> + linux,keycode = <108>; /* KEY_DOWN */
> + };
> + left {
> + linux,keycode = <105>; /* KEY_LEFT */
> + };
> + pagedown {
> + linux,keycode = <109>; /* KEY_PAGEDOWN */
> + };
> + pageup {
> + linux,keycode = <104>; /* KEY_PAGEUP */
> + };
> + };
> +}
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index f7e79b4..a3958c6 100644
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@ -665,4 +665,14 @@ config KEYBOARD_CROS_EC
> To compile this driver as a module, choose M here: the
> module will be called cros_ec_keyb.
>
> +config KEYBOARD_CAP1106
> + tristate "Microchip CAP1106 touch sensor"
> + depends on OF && I2C
> + select REGMAP_I2C
> + help
> + Say Y here to enable the CAP1106 touch sensor driver.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called cap1106.
> +
> endif
> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
> index 7504ae1..0a33456 100644
> --- a/drivers/input/keyboard/Makefile
> +++ b/drivers/input/keyboard/Makefile
> @@ -11,6 +11,7 @@ obj-$(CONFIG_KEYBOARD_AMIGA) += amikbd.o
> obj-$(CONFIG_KEYBOARD_ATARI) += atakbd.o
> obj-$(CONFIG_KEYBOARD_ATKBD) += atkbd.o
> obj-$(CONFIG_KEYBOARD_BFIN) += bf54x-keys.o
> +obj-$(CONFIG_KEYBOARD_CAP1106) += cap1106.o
> obj-$(CONFIG_KEYBOARD_CLPS711X) += clps711x-keypad.o
> obj-$(CONFIG_KEYBOARD_CROS_EC) += cros_ec_keyb.o
> obj-$(CONFIG_KEYBOARD_DAVINCI) += davinci_keyscan.o
> diff --git a/drivers/input/keyboard/cap1106.c
> b/drivers/input/keyboard/cap1106.c
> new file mode 100644
> index 0000000..ad0f0fb
> --- /dev/null
> +++ b/drivers/input/keyboard/cap1106.c
> @@ -0,0 +1,376 @@
> +/*
> + * Input driver for Microchip CAP1106, 6 channel capacitive touch sensor
> + *
> + * http://www.microchip.com/wwwproducts/Devices.aspx?product=CAP1106
> + *
> + * (c) 2014 Daniel Mack <[email protected]>
> + *
> + * 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;
> + struct work_struct work;
> + spinlock_t lock;
> + int irq;
> +
> + /* 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 void cap1106_work(struct work_struct *w)
> +{
> + struct cap1106_priv *priv = container_of(w, struct cap1106_priv,
> work);
> + unsigned int status;
> + int ret, i;
> +
> + spin_lock(&priv->lock);
If your worker started and is _about_ to take the spinlock, you might
dead-lock with cap1106_close(). They might already hold the spinlock
and then call cancel_work_sync(), thus waiting for this task to take
the lock end exit..
How about you add "bool closed : 1;" to your cap1106_priv structure
and drop the lock here, but..
> +
> + /*
> + * 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:
> + enable_irq(priv->irq);
> + spin_unlock(&priv->lock);
...change this to:
spin_lock(&priv->lock);
if (!priv->closed)
enable_irq(priv->irq);
spin_unlock(&priv->lock);
> +}
> +
> +static irqreturn_t cap1106_isr(int irq_num, void *data)
> +{
> + struct cap1106_priv *priv = data;
> +
> + spin_lock(&priv->lock);
> + disable_irq_nosync(priv->irq);
> + schedule_work(&priv->work);
> + spin_unlock(&priv->lock);
Locks here can be simply dropped. The IRQ is always stopped
synchronously before any worker is stopped, so this cannot race.
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int cap1106_open(struct input_dev *input_dev)
> +{
> + struct cap1106_priv *priv = input_get_drvdata(input_dev);
> + int ret;
> +
> + /* disable deep sleep */
> + ret = regmap_update_bits(priv->regmap, CAP1106_REG_MAIN_CONTROL,
> + CAP1106_REG_MAIN_CONTROL_DLSEEP, 0);
> +
You'd have to add:
priv->closed = false;
No need for locking as enable_irq and work-structs work as barriers.
> + enable_irq(priv->irq);
> +
> + return ret;
> +}
> +
> +static void cap1106_close(struct input_dev *input_dev)
> +{
> + struct cap1106_priv *priv = input_get_drvdata(input_dev);
> + unsigned long flags;
> +
> + spin_lock_irqsave(&priv->lock, flags);
> + disable_irq(priv->irq);
> + cancel_work_sync(&priv->work);
> + spin_unlock_irqrestore(&priv->lock, flags);
This would become:
spin_lock(&priv->lock);
priv->closed = true;
disable_irq(priv->irq);
spin_unlock(&priv->lock);
cancel_work_sync(&priv->work);
Btw., no need for irqsave/irqrestore here, ->closed is called in user-context.
Everything else looks good to me:
Thanks
David
> +
> + /* enable deep sleep */
> + regmap_update_bits(priv->regmap, CAP1106_REG_MAIN_CONTROL,
> + CAP1106_REG_MAIN_CONTROL_DLSEEP,
> + CAP1106_REG_MAIN_CONTROL_DLSEEP);
> +}
> +
> +static int cap1106_i2c_probe(struct i2c_client *i2c_client,
> + const struct i2c_device_id *id)
> +{
> + struct device *dev = &i2c_client->dev;
> + struct device_node *child, *node;
> + struct cap1106_priv *priv;
> + unsigned int val, rev;
> + u8 gain = 0;
> + int i, ret;
> + u32 tmp32;
> +
> + 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);
> +
> + ret = regmap_read(priv->regmap, CAP1106_REG_PRODUCT_ID, &val);
> + if (ret < 0)
> + return ret;
> +
> + if (val != CAP1106_PRODUCT_ID) {
> + dev_err(dev, "Product ID: Got 0x%02x, expected 0x%02x\n",
> + val, CAP1106_PRODUCT_ID);
> + return -ENODEV;
> + }
> +
> + ret = regmap_read(priv->regmap, CAP1106_REG_MANUFACTURER_ID, &val);
> + if (ret < 0)
> + return ret;
> +
> + if (val != CAP1106_MANUFACTURER_ID) {
> + dev_err(dev, "Manufacturer ID: Got 0x%02x, expected 0x%02x\n",
> + val, CAP1106_MANUFACTURER_ID);
> + return -ENODEV;
> + }
> +
> + ret = regmap_read(priv->regmap, CAP1106_REG_REVISION, &rev);
> + if (ret < 0)
> + return ret;
> +
> + dev_info(dev, "CAP1106 detected, revision 0x%02x\n", rev);
> + i2c_set_clientdata(i2c_client, priv);
> + INIT_WORK(&priv->work, cap1106_work);
> + spin_lock_init(&priv->lock);
> + node = dev->of_node;
> +
> + if (!of_property_read_u32(node, "microchip,sensor-gain", &tmp32)) {
> + if (is_power_of_2(tmp32) && tmp32 <= 8)
> + gain = ilog2(tmp32);
> + else
> + dev_err(dev, "Invalid sensor-gain value %d\n", tmp32);
> + }
> +
> + ret = regmap_update_bits(priv->regmap, CAP1106_REG_MAIN_CONTROL,
> + CAP1106_REG_MAIN_CONTROL_GAIN_MASK,
> + gain << CAP1106_REG_MAIN_CONTROL_GAIN_SHIFT);
> + if (ret < 0)
> + return ret;
> +
> + /* disable autorepeat. The Linux input system has its own handling. */
> + ret = regmap_write(priv->regmap, CAP1106_REG_REPEAT_RATE, 0);
> + if (ret < 0)
> + return ret;
> +
> + /* set the defaults */
> + for (i = 0; i < CAP1106_NUM_CHN; i++)
> + priv->keycodes[i] = KEY_A + i;
> +
> + i = 0;
> + for_each_child_of_node(node, child) {
> + if (i == CAP1106_NUM_CHN) {
> + dev_err(dev, "Too many button nodes.\n");
> + return -EINVAL;
> + }
> +
> + if (!of_property_read_u32(child, "linux,keycode", &tmp32))
> + priv->keycodes[i] = tmp32;
> +
> + i++;
> + }
> +
> + 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_get_property(node, "autorepeat", NULL))
> + __set_bit(EV_REP, priv->idev->evbit);
> +
> + for (i = 0; i < CAP1106_NUM_CHN; i++) {
> + unsigned int code = priv->keycodes[i];
> + priv->idev->keybit[BIT_WORD(code)] |= BIT_MASK(code);
> + }
> +
> + priv->idev->id.vendor = CAP1106_MANUFACTURER_ID;
> + priv->idev->id.product = CAP1106_PRODUCT_ID;
> + priv->idev->id.version = rev;
> +
> + priv->idev->open = cap1106_open;
> + priv->idev->close = cap1106_close;
> +
> + input_set_drvdata(priv->idev, priv);
> +
> + ret = input_register_device(priv->idev);
> + if (ret < 0)
> + return ret;
> +
> + priv->irq = irq_of_parse_and_map(node, 0);
> + if (!priv->irq) {
> + dev_err(dev, "Unable to parse or map IRQ\n");
> + return -ENXIO;
> + }
> +
> + ret = devm_request_irq(dev, priv->irq, cap1106_isr, IRQF_DISABLED,
> + dev_name(dev), priv);
> + if (ret < 0)
> + return ret;
> +
> + return 0;
> +}
> +
> +static int cap1106_i2c_remove(struct i2c_client *i2c_client)
> +{
> + struct cap1106_priv *priv = i2c_get_clientdata(i2c_client);
> +
> + input_unregister_device(priv->idev);
> +
> + 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,
> + .remove = cap1106_i2c_remove,
> +};
> +
> +module_i2c_driver(cap1106_i2c_driver);
> +
> +MODULE_ALIAS("platform:" DRV_NAME);
> +MODULE_DESCRIPTION("Microchip CAP1106 driver");
> +MODULE_AUTHOR("Daniel Mack <[email protected]>");
> +MODULE_LICENSE("GPL v2");
> --
> 1.9.3
>
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