From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751913AbcG1WJY (ORCPT ); Thu, 28 Jul 2016 18:09:24 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:34211 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751375AbcG1WJW (ORCPT ); Thu, 28 Jul 2016 18:09:22 -0400 Date: Thu, 28 Jul 2016 15:09:18 -0700 From: Dmitry Torokhov To: Alexandre Belloni Cc: Jonathan Cameron , linux-input@vger.kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 2/2] input: add ADC resistor ladder driver Message-ID: <20160728220918.GA25461@dtor-ws> References: <1468352186-14190-1-git-send-email-alexandre.belloni@free-electrons.com> <1468352186-14190-2-git-send-email-alexandre.belloni@free-electrons.com> <20160713004150.GB24789@dtor-ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160713004150.GB24789@dtor-ws> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 12, 2016 at 05:41:50PM -0700, Dmitry Torokhov wrote: > Hi Alexandre, > > On Tue, Jul 12, 2016 at 09:36:26PM +0200, Alexandre Belloni wrote: > > A common way of multiplexing buttons on a single input in cheap devices is > > to use a resistor ladder on an ADC. This driver supports that configuration > > by polling an ADC channel provided by IIO. > > This looks quite reasonable, just a few small comments. Ping. Did the version below work for you? I am trying sweep in the brand new drivers before we close merge window. Thanks! > > > > > Acked-by: Jonathan Cameron > > Signed-off-by: Alexandre Belloni > > --- > > drivers/input/keyboard/Kconfig | 15 +++ > > drivers/input/keyboard/Makefile | 1 + > > drivers/input/keyboard/adc-keys.c | 210 ++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 226 insertions(+) > > create mode 100644 drivers/input/keyboard/adc-keys.c > > > > diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig > > index 509608c95994..4cf042cc5e63 100644 > > --- a/drivers/input/keyboard/Kconfig > > +++ b/drivers/input/keyboard/Kconfig > > @@ -12,6 +12,21 @@ menuconfig INPUT_KEYBOARD > > > > if INPUT_KEYBOARD > > > > +config KEYBOARD_ADC > > + tristate "ADC ladder Buttons" > > + depends on IIO > > + select INPUT_POLLDEV > > + help > > + This driver implements support for buttons connected > > + to an ADC using a resistor ladder. > > + > > + Say Y here if your device has such buttons connected to an ADC. Your > > + board-specific setup logic must also provide a configuration data > > + saying mapping voltages to buttons. > > + > > + 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 1d416ddf84e4..d9f4cfcf3410 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 000000000000..cf299ff517a0 > > --- /dev/null > > +++ b/drivers/input/keyboard/adc-keys.c > > @@ -0,0 +1,210 @@ > > +/* Input driver for resistor ladder connected on ADC > > + * > > + * Copyright (c) 2016 Alexandre Belloni > > + * > > + * 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 > > +#include > > +#include > > + > > +struct adc_keys_button { > > + u32 voltage; > > + u32 keycode; > > +}; > > + > > +struct adc_keys_state { > > + struct iio_channel *channel; > > + u32 num_keys; > > + u32 last_key; > > + u32 keyup_voltage; > > + struct adc_keys_button *map; > > const > > > +}; > > + > > +static void adc_keys_poll(struct input_polled_dev *dev) > > +{ > > + struct adc_keys_state *st = dev->private; > > + int i, value, ret; > > + u32 diff, closest = 0xffffffff; > > + int keycode = 0; > > + > > + ret = iio_read_channel_processed(st->channel, &value); > > + if (ret < 0) { > > > + if (st->last_key) { > > + input_report_key(dev->input, st->last_key, 0); > > + input_sync(dev->input); > > + st->last_key = 0; > > + } > > + return; > > + } > > + > > + for (i = 0; i < st->num_keys; i++) { > > + diff = abs(st->map[i].voltage - value); > > + if (diff < closest) { > > + closest = diff; > > + keycode = st->map[i].keycode; > > + } > > + } > > + > > + if (abs(st->keyup_voltage - value) < closest) { > > + input_report_key(dev->input, st->last_key, 0); > > + st->last_key = 0; > > + } else { > > + if (st->last_key && st->last_key != keycode) > > + input_report_key(dev->input, st->last_key, 0); > > + input_report_key(dev->input, keycode, 1); > > + st->last_key = keycode; > > + } > > I think this can be simplified a bit, see version below. > > > + > > + input_sync(dev->input); > > +} > > + > > +static int adc_keys_load_dt_keymap(struct device *dev, > > + struct adc_keys_state *st) > > +{ > > + struct device_node *pp, *np = dev->of_node; > > + int i; > > + > > + st->num_keys = of_get_child_count(np); > > + if (st->num_keys == 0) { > > + dev_err(dev, "keymap is missing\n"); > > + return -EINVAL; > > + } > > There is no need to limit this driver to OF, generic device properties > will allow us to use it on DT, ACPI and legacy boards. > > > + > > + st->map = devm_kmalloc_array(dev, st->num_keys, sizeof(*st->map), > > + GFP_KERNEL); > > + if (!st->map) > > + return -ENOMEM; > > + > > + i = 0; > > + for_each_child_of_node(np, pp) { > > + struct adc_keys_button *map = &st->map[i]; > > + > > + if (of_property_read_u32(pp, "press-threshold-mvolt", > > + &map->voltage)) { > > + dev_err(dev, "%s: Invalid or missing voltage\n", > > + pp->name); > > You have to remember to drop node reference if you return early from > for_each_child_of_node(). > > > + return -EINVAL; > > + } > > + > > + if (of_property_read_u32(pp, "linux,code", &map->keycode)) { > > + dev_err(dev, "%s: Invalid or missing linux,code\n", > > + pp->name); > > + return -EINVAL; > > + } > > + > > + i++; > > + } > > + > > + return 0; > > +} > > + > > +static int adc_keys_probe(struct platform_device *pdev) > > +{ > > + struct device *dev = &pdev->dev; > > + struct device_node *node = dev->of_node; > > + struct adc_keys_state *st; > > + struct input_polled_dev *poll_dev = NULL; > > + struct input_dev *input; > > + enum iio_chan_type type; > > + int i, value, ret; > > + > > + st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); > > + if (!st) > > + return -ENOMEM; > > + > > + st->channel = devm_iio_channel_get(dev, "buttons"); > > + if (IS_ERR(st->channel)) > > + return PTR_ERR(st->channel); > > + > > + if (!st->channel->indio_dev) > > + return -ENODEV; > > + > > + ret = iio_get_channel_type(st->channel, &type); > > + if (ret < 0) > > + return ret; > > + > > + if (type != IIO_VOLTAGE) { > > + dev_err(dev, "Incompatible channel type %d\n", type); > > + return -EINVAL; > > + } > > + > > + if (of_property_read_u32(node, "keyup-threshold-mvolt", > > + &st->keyup_voltage)) { > > + dev_err(dev, "Invalid or missing keyup voltage\n"); > > + return -EINVAL; > > + } > > + > > + ret = adc_keys_load_dt_keymap(dev, st); > > + if (ret) > > + return ret; > > + > > + platform_set_drvdata(pdev, st); > > + > > + poll_dev = devm_input_allocate_polled_device(dev); > > + if (!poll_dev) { > > + dev_err(dev, "failed to allocate input device\n"); > > + return -ENOMEM; > > + } > > + > > + if (!of_property_read_u32(node, "poll-interval", &value)) > > + poll_dev->poll_interval = value; > > + poll_dev->poll = adc_keys_poll; > > + poll_dev->private = st; > > + > > + input = poll_dev->input; > > + > > + input->name = pdev->name; > > + input->phys = "adc-keys/input0"; > > + input->dev.parent = &pdev->dev; > > No need to do that for devm input devices - it is done for you. > > > + > > + input->id.bustype = BUS_HOST; > > + input->id.vendor = 0x0001; > > + input->id.product = 0x0001; > > + input->id.version = 0x0100; > > + > > + __set_bit(EV_KEY, input->evbit); > > + for (i = 0; i < st->num_keys; i++) > > + __set_bit(st->map[i].keycode, input->keybit); > > + > > + if (!!of_get_property(node, "autorepeat", NULL)) > > + __set_bit(EV_REP, input->evbit); > > + > > + ret = input_register_polled_device(poll_dev); > > + if (ret) { > > + dev_err(dev, "Unable to register input device\n"); > > + return ret; > > + } > > + > > + return 0; > > +} > > + > > +static const struct of_device_id adc_keys_of_match[] = { > > + { .compatible = "adc-keys", }, > > + { } > > +}; > > +MODULE_DEVICE_TABLE(of, adc_keys_of_match); > > Needs #ifdef CONFIG_OF. > > > + > > +static struct platform_driver __refdata adc_keys_driver = { > > + .driver = { > > + .name = "adc_keys", > > + .of_match_table = adc_keys_of_match, > > of_match_ptr(). > > > + }, > > + .probe = adc_keys_probe, > > +}; > > + > > +module_platform_driver(adc_keys_driver); > > + > > +MODULE_AUTHOR("Alexandre Belloni "); > > +MODULE_DESCRIPTION("Input driver for resistor ladder connected on ADC"); > > +MODULE_LICENSE("GPL v2"); > > -- > > 2.8.1 > > > > Thanks. > > -- > Dmitry > > > Input: add ADC resistor ladder driver > > From: Alexandre Belloni > > A common way of multiplexing buttons on a single input in cheap devices is > to use a resistor ladder on an ADC. This driver supports that configuration > by polling an ADC channel provided by IIO. > > Acked-by: Jonathan Cameron > Signed-off-by: Alexandre Belloni > Signed-off-by: Dmitry Torokhov > --- > .../devicetree/bindings/input/adc-keys.txt | 49 +++++ > drivers/input/keyboard/Kconfig | 15 + > drivers/input/keyboard/Makefile | 1 > drivers/input/keyboard/adc-keys.c | 208 ++++++++++++++++++++ > 4 files changed, 273 insertions(+) > create mode 100644 Documentation/devicetree/bindings/input/adc-keys.txt > create mode 100644 drivers/input/keyboard/adc-keys.c > > diff --git a/Documentation/devicetree/bindings/input/adc-keys.txt b/Documentation/devicetree/bindings/input/adc-keys.txt > new file mode 100644 > index 0000000..feab05a > --- /dev/null > +++ b/Documentation/devicetree/bindings/input/adc-keys.txt > @@ -0,0 +1,49 @@ > +ADC attached resistor ladder buttons > +------------------------------------ > + > +Required properties: > + - compatible: "adc-keys" > + - io-channels: Phandle to an ADC channel > + - io-channel-names = "buttons"; > + - keyup-threshold-mvolt: Voltage at which all the keys are considered up. > + > +Optional properties: > + - poll-interval: Poll interval time in milliseconds > + - autorepeat: Boolean, Enable auto repeat feature of Linux input > + subsystem. > + > +Each button (key) is represented as a sub-node of "adc-keys": > + > +Required subnode-properties: > + - label: Descriptive name of the key. > + - linux,code: Keycode to emit. > + - press-threshold-mvolt: Voltage adc input when this key is pressed. > + > +Example: > + > +#include > + > + adc-keys { > + compatible = "adc-keys"; > + io-channels = <&lradc 0>; > + io-channel-names = "buttons"; > + keyup-threshold-mvolt = <2000>; > + > + button@1500 { > + label = "Volume Up"; > + linux,code = ; > + press-threshold-mvolt = <1500>; > + }; > + > + button@1000 { > + label = "Volume Down"; > + linux,code = ; > + press-threshold-mvolt = <1000>; > + }; > + > + button@500 { > + label = "Enter"; > + linux,code = ; > + press-threshold-mvolt = <500>; > + }; > + }; > diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig > index 509608c..cbd75cf 100644 > --- a/drivers/input/keyboard/Kconfig > +++ b/drivers/input/keyboard/Kconfig > @@ -12,6 +12,21 @@ menuconfig INPUT_KEYBOARD > > if INPUT_KEYBOARD > > +config KEYBOARD_ADC > + tristate "ADC Ladder Buttons" > + depends on IIO > + select INPUT_POLLDEV > + help > + This driver implements support for buttons connected > + to an ADC using a resistor ladder. > + > + Say Y here if your device has such buttons connected to an ADC. Your > + board-specific setup logic must also provide a configuration data > + for mapping voltages to buttons. > + > + 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 1d416dd..d9f4cfc 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..f91eec5 > --- /dev/null > +++ b/drivers/input/keyboard/adc-keys.c > @@ -0,0 +1,208 @@ > +/* > + * Input driver for resistor ladder connected on ADC > + * > + * Copyright (c) 2016 Alexandre Belloni > + * > + * 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 > +#include > +#include > +#include > + > +struct adc_keys_button { > + u32 voltage; > + u32 keycode; > +}; > + > +struct adc_keys_state { > + struct iio_channel *channel; > + u32 num_keys; > + u32 last_key; > + u32 keyup_voltage; > + const struct adc_keys_button *map; > +}; > + > +static void adc_keys_poll(struct input_polled_dev *dev) > +{ > + struct adc_keys_state *st = dev->private; > + int i, value, ret; > + u32 diff, closest = 0xffffffff; > + int keycode = 0; > + > + ret = iio_read_channel_processed(st->channel, &value); > + if (unlikely(ret < 0)) { > + /* Forcibly release key if any was pressed */ > + value = st->keyup_voltage; > + } else { > + for (i = 0; i < st->num_keys; i++) { > + diff = abs(st->map[i].voltage - value); > + if (diff < closest) { > + closest = diff; > + keycode = st->map[i].keycode; > + } > + } > + } > + > + if (abs(st->keyup_voltage - value) < closest) > + keycode = 0; > + > + if (st->last_key && st->last_key != keycode) > + input_report_key(dev->input, st->last_key, 0); > + > + if (keycode) > + input_report_key(dev->input, keycode, 1); > + > + input_sync(dev->input); > + st->last_key = keycode; > +} > + > +static int adc_keys_load_keymap(struct device *dev, struct adc_keys_state *st) > +{ > + struct adc_keys_button *map; > + struct fwnode_handle *child; > + int i; > + > + st->num_keys = device_get_child_node_count(dev); > + if (st->num_keys == 0) { > + dev_err(dev, "keymap is missing\n"); > + return -EINVAL; > + } > + > + map = devm_kmalloc_array(dev, st->num_keys, sizeof(*map), GFP_KERNEL); > + if (!map) > + return -ENOMEM; > + > + i = 0; > + device_for_each_child_node(dev, child) { > + if (fwnode_property_read_u32(child, "press-threshold-mvolt", > + &map[i].voltage)) { > + dev_err(dev, "Key with invalid or missing voltage\n"); > + fwnode_handle_put(child); > + return -EINVAL; > + } > + > + if (fwnode_property_read_u32(child, "linux,code", > + &map[i].keycode)) { > + dev_err(dev, "Key with invalid or missing linux,code\n"); > + fwnode_handle_put(child); > + return -EINVAL; > + } > + > + i++; > + } > + > + st->map = map; > + return 0; > +} > + > +static int adc_keys_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct adc_keys_state *st; > + struct input_polled_dev *poll_dev; > + struct input_dev *input; > + enum iio_chan_type type; > + int i, value; > + int error; > + > + st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); > + if (!st) > + return -ENOMEM; > + > + st->channel = devm_iio_channel_get(dev, "buttons"); > + if (IS_ERR(st->channel)) > + return PTR_ERR(st->channel); > + > + if (!st->channel->indio_dev) > + return -ENXIO; > + > + error = iio_get_channel_type(st->channel, &type); > + if (error < 0) > + return error; > + > + if (type != IIO_VOLTAGE) { > + dev_err(dev, "Incompatible channel type %d\n", type); > + return -EINVAL; > + } > + > + if (device_property_read_u32(dev, "keyup-threshold-mvolt", > + &st->keyup_voltage)) { > + dev_err(dev, "Invalid or missing keyup voltage\n"); > + return -EINVAL; > + } > + > + error = adc_keys_load_keymap(dev, st); > + if (error) > + return error; > + > + platform_set_drvdata(pdev, st); > + > + poll_dev = devm_input_allocate_polled_device(dev); > + if (!poll_dev) { > + dev_err(dev, "failed to allocate input device\n"); > + return -ENOMEM; > + } > + > + if (!device_property_read_u32(dev, "poll-interval", &value)) > + poll_dev->poll_interval = value; > + > + poll_dev->poll = adc_keys_poll; > + poll_dev->private = st; > + > + 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; > + > + __set_bit(EV_KEY, input->evbit); > + for (i = 0; i < st->num_keys; i++) > + __set_bit(st->map[i].keycode, input->keybit); > + > + if (device_property_read_bool(dev, "autorepeat")) > + __set_bit(EV_REP, input->evbit); > + > + error = input_register_polled_device(poll_dev); > + if (error) { > + dev_err(dev, "Unable to register input device: %d\n", error); > + return error; > + } > + > + return 0; > +} > + > +#ifdef CONFIG_OF > +static const struct of_device_id adc_keys_of_match[] = { > + { .compatible = "adc-keys", }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, adc_keys_of_match); > +#endif > + > +static struct platform_driver __refdata adc_keys_driver = { > + .driver = { > + .name = "adc_keys", > + .of_match_table = of_match_ptr(adc_keys_of_match), > + }, > + .probe = adc_keys_probe, > +}; > +module_platform_driver(adc_keys_driver); > + > +MODULE_AUTHOR("Alexandre Belloni "); > +MODULE_DESCRIPTION("Input driver for resistor ladder connected on ADC"); > +MODULE_LICENSE("GPL v2"); -- Dmitry