On 28/03/15 00:43, Andrew Bresticker wrote: > Add a polled input driver for a keypad in which the buttons are connected > in resistor ladders to an ADC. The IIO framework is used to claim and > read the ADC channels. > > Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx> The IIO side of things looks fine. > --- > drivers/input/keyboard/Kconfig | 13 ++ > drivers/input/keyboard/Makefile | 1 + > drivers/input/keyboard/adc-keys.c | 291 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 305 insertions(+) > create mode 100644 drivers/input/keyboard/adc-keys.c > > diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig > index a89ba7c..bbaff9e 100644 > --- a/drivers/input/keyboard/Kconfig > +++ b/drivers/input/keyboard/Kconfig > @@ -12,6 +12,19 @@ menuconfig INPUT_KEYBOARD > > if INPUT_KEYBOARD > > +config KEYBOARD_ADC > + tristate "ADC Keypad" > + depends on IIO > + select INPUT_POLLDEV > + help > + This driver supports generic ADC keypads using IIO. > + > + Say Y here if your device has buttons connected in a resistor ladder > + to an ADC. > + > + To compile this driver as a module, choose M here: the module will > + be called adc-keys. > + > config KEYBOARD_ADP5520 > tristate "Keypad Support for ADP5520 PMIC" > depends on PMIC_ADP5520 > diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile > index 4707678..888fa62 100644 > --- a/drivers/input/keyboard/Makefile > +++ b/drivers/input/keyboard/Makefile > @@ -4,6 +4,7 @@ > > # Each configuration option enables a list of files. > > +obj-$(CONFIG_KEYBOARD_ADC) += adc-keys.o > obj-$(CONFIG_KEYBOARD_ADP5520) += adp5520-keys.o > obj-$(CONFIG_KEYBOARD_ADP5588) += adp5588-keys.o > obj-$(CONFIG_KEYBOARD_ADP5589) += adp5589-keys.o > diff --git a/drivers/input/keyboard/adc-keys.c b/drivers/input/keyboard/adc-keys.c > new file mode 100644 > index 0000000..1b9bcad > --- /dev/null > +++ b/drivers/input/keyboard/adc-keys.c > @@ -0,0 +1,291 @@ > +/* > + * ADC keypad driver > + * > + * Copyright (C) 2015 Google, Inc. > + * > + * Based on /drivers/input/keybaord/gpio_keys_polled.c: > + * Copyright (C) 2007-2010 Gabor Juhos <juhosg@xxxxxxxxxxx> > + * Copyright (C) 2010 Nuno Goncalves <nunojpg@xxxxxxxxx> > + * > + * 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/iio/consumer.h> > +#include <linux/input.h> > +#include <linux/input-polldev.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/slab.h> > + > +struct adc_key { > + const char *desc; > + unsigned int type; > + unsigned int code; > + unsigned int min_uV; > + unsigned int max_uV; > +}; > + > +struct adc_chan_map { > + struct adc_key *keys; > + unsigned int num_keys; > + int last_key; > +}; > + > +struct adc_keypad { > + struct device *dev; > + struct input_polled_dev *poll_dev; > + unsigned int poll_interval; > + bool autorepeat; > + struct iio_channel *iio_chans; > + unsigned int num_chans; > + struct adc_chan_map *chan_map; > +}; > + > +static void adc_keypad_poll_chan(struct adc_keypad *keypad, unsigned int chan) > +{ > + struct adc_chan_map *chan_map = &keypad->chan_map[chan]; > + struct input_dev *input = keypad->poll_dev->input; > + struct adc_key *key; > + unsigned int adc_uV; > + int ret, val, i; > + > + ret = iio_read_channel_processed(&keypad->iio_chans[chan], &val); > + if (ret < 0) { > + dev_err(keypad->dev, "Failed to read ADC: %d\n", ret); > + return; > + } > + adc_uV = val * 1000; > + > + for (i = 0; i < chan_map->num_keys; i++) { > + if (adc_uV >= chan_map->keys[i].min_uV && > + adc_uV <= chan_map->keys[i].max_uV) > + break; > + } > + if (i >= chan_map->num_keys) > + i = -1; > + > + if (i != chan_map->last_key) { > + if (chan_map->last_key >= 0) { > + key = &chan_map->keys[chan_map->last_key]; > + input_event(input, key->type, key->code, 0); > + } > + if (i >= 0) { > + key = &chan_map->keys[i]; > + input_event(input, key->type, key->code, 1); > + } > + input_sync(input); > + chan_map->last_key = i; > + } > +} > + > +static void adc_keypad_poll(struct input_polled_dev *poll_dev) > +{ > + struct adc_keypad *keypad = poll_dev->private; > + unsigned int i; > + > + for (i = 0; i < keypad->num_chans; i++) > + adc_keypad_poll_chan(keypad, i); > +} > + > +static int adc_keypad_of_parse_chan(struct adc_keypad *keypad, > + unsigned int chan) > +{ > + struct device_node *child, *np = keypad->dev->of_node; > + struct adc_key *keys; > + unsigned int i = 0; > + int ret; > + > + for_each_child_of_node(np, child) { > + unsigned int c; > + > + ret = of_property_read_u32(child, "channel", &c); > + if (ret < 0) > + continue; > + if (c != chan) > + continue; > + i++; > + } > + > + keys = devm_kcalloc(keypad->dev, i, sizeof(*keys), GFP_KERNEL); > + if (!keys) > + return -ENOMEM; > + keypad->chan_map[chan].keys = keys; > + keypad->chan_map[chan].num_keys = i; > + > + i = 0; > + for_each_child_of_node(np, child) { > + struct adc_key *key = &keys[i]; > + unsigned int c; > + > + ret = of_property_read_u32(child, "channel", &c); > + if (ret < 0) > + continue; > + if (c != chan) > + continue; > + > + ret = of_property_read_string(child, "label", &key->desc); > + if (ret < 0) > + return ret; > + > + ret = of_property_read_u32(child, "min-voltage", &key->min_uV); > + if (ret < 0) > + return ret; > + > + ret = of_property_read_u32(child, "max-voltage", &key->max_uV); > + if (ret < 0) > + return ret; > + > + ret = of_property_read_u32(child, "linux,code", &key->code); > + if (ret < 0) > + return ret; > + > + ret = of_property_read_u32(child, "linux,input-type", > + &key->type); > + if (ret < 0) > + key->type = EV_KEY; > + > + i++; > + if (i >= keypad->chan_map[chan].num_keys) > + break; > + } > + > + return 0; > +} > + > +static int adc_keypad_of_parse(struct adc_keypad *keypad) > +{ > + struct device_node *np = keypad->dev->of_node; > + unsigned int i; > + int ret; > + > + keypad->autorepeat = of_property_read_bool(np, "autorepeat"); > + ret = of_property_read_u32(np, "poll-interval", &keypad->poll_interval); > + if (ret < 0) > + return ret; > + > + for (i = 0; i < keypad->num_chans; i++) { > + ret = adc_keypad_of_parse_chan(keypad, i); > + if (ret < 0) > + return ret; > + } > + > + return 0; > +} > + > +static int adc_keypad_probe(struct platform_device *pdev) > +{ > + struct adc_keypad *keypad; > + struct input_polled_dev *poll_dev; > + struct input_dev *input; > + unsigned int i; > + int ret; > + > + keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL); > + if (!keypad) > + return -ENOMEM; > + keypad->dev = &pdev->dev; > + platform_set_drvdata(pdev, keypad); > + > + keypad->iio_chans = iio_channel_get_all(&pdev->dev); > + if (IS_ERR(keypad->iio_chans)) { > + dev_err(&pdev->dev, "Failed to get IIO channels: %ld\n", > + PTR_ERR(keypad->iio_chans)); > + return PTR_ERR(keypad->iio_chans); > + } > + > + i = 0; > + while (keypad->iio_chans[i].channel != NULL) > + i++; > + keypad->num_chans = i; > + keypad->chan_map = devm_kcalloc(&pdev->dev, keypad->num_chans, > + sizeof(*keypad->chan_map), GFP_KERNEL); > + if (!keypad->chan_map) { > + ret = -ENOMEM; > + goto put_chans; > + } > + > + ret = adc_keypad_of_parse(keypad); > + if (ret < 0) > + goto put_chans; > + > + poll_dev = devm_input_allocate_polled_device(&pdev->dev); > + if (!poll_dev) { > + ret = -ENOMEM; > + goto put_chans; > + } > + keypad->poll_dev = poll_dev; > + > + poll_dev->private = keypad; > + poll_dev->poll = adc_keypad_poll; > + poll_dev->poll_interval = keypad->poll_interval; > + > + input = poll_dev->input; > + input->name = pdev->name; > + input->phys = "adc-keys/input0"; > + > + input->id.bustype = BUS_HOST; > + input->id.vendor = 0x0001; > + input->id.product = 0x0001; > + input->id.version = 0x0100; Why these particular values? > + > + __set_bit(EV_KEY, input->evbit); > + if (keypad->autorepeat) > + __set_bit(EV_REP, input->evbit); > + > + for (i = 0; i < keypad->num_chans; i++) { > + struct adc_chan_map *chan_map = &keypad->chan_map[i]; > + unsigned int j; > + > + for (j = 0; j < chan_map->num_keys; j++) > + input_set_capability(input, chan_map->keys[j].type, > + chan_map->keys[j].code); > + } > + > + ret = input_register_polled_device(poll_dev); > + if (ret < 0) { > + dev_err(&pdev->dev, "Failed to register polled device: %d\n", > + ret); > + goto put_chans; > + } > + > + return 0; > + > +put_chans: > + iio_channel_release_all(keypad->iio_chans); > + return ret; > +} > + > +static int adc_keypad_remove(struct platform_device *pdev) > +{ > + struct adc_keypad *keypad = platform_get_drvdata(pdev); > + > + input_unregister_polled_device(keypad->poll_dev); > + > + iio_channel_release_all(keypad->iio_chans); > + > + return 0; > +} > + > +static const struct of_device_id adc_keypad_of_match[] = { > + { .compatible = "adc-keys", }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, adc_keypad_of_match); > + > +static struct platform_driver adc_keypad_driver = { > + .probe = adc_keypad_probe, > + .remove = adc_keypad_remove, > + .driver = { > + .name = "adc-keys", > + .of_match_table = adc_keypad_of_match, > + }, > +}; > +module_platform_driver(adc_keypad_driver); > + > +MODULE_DESCRIPTION("ADC keypad driver"); > +MODULE_AUTHOR("Andrew Bresticker <abrestic@xxxxxxxxxxxx>"); > +MODULE_LICENSE("GPL v2"); > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html