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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/input/keyboard/adc-keys.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'drivers/input/keyboard/adc-keys.c')
-rw-r--r--drivers/input/keyboard/adc-keys.c204
1 files changed, 204 insertions, 0 deletions
diff --git a/drivers/input/keyboard/adc-keys.c b/drivers/input/keyboard/adc-keys.c
new file mode 100644
index 000000000..f17532074
--- /dev/null
+++ b/drivers/input/keyboard/adc-keys.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Input driver for resistor ladder connected on ADC
+ *
+ * Copyright (c) 2016 Alexandre Belloni
+ */
+
+#include <linux/err.h>
+#include <linux/iio/consumer.h>
+#include <linux/iio/types.h>
+#include <linux/input.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+
+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_dev *input)
+{
+ struct adc_keys_state *st = input_get_drvdata(input);
+ 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(input, st->last_key, 0);
+
+ if (keycode)
+ input_report_key(input, keycode, 1);
+
+ input_sync(input);
+ st->last_key = keycode;
+}
+
+static int adc_keys_load_keymap(struct device *dev, struct adc_keys_state *st)
+{
+ struct adc_keys_button *map;
+ 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_scoped(dev, child) {
+ if (fwnode_property_read_u32(child, "press-threshold-microvolt",
+ &map[i].voltage)) {
+ dev_err(dev, "Key with invalid or missing voltage\n");
+ return -EINVAL;
+ }
+ map[i].voltage /= 1000;
+
+ if (fwnode_property_read_u32(child, "linux,code",
+ &map[i].keycode)) {
+ dev_err(dev, "Key with invalid or missing linux,code\n");
+ 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_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-microvolt",
+ &st->keyup_voltage)) {
+ dev_err(dev, "Invalid or missing keyup voltage\n");
+ return -EINVAL;
+ }
+ st->keyup_voltage /= 1000;
+
+ error = adc_keys_load_keymap(dev, st);
+ if (error)
+ return error;
+
+ input = devm_input_allocate_device(dev);
+ if (!input) {
+ dev_err(dev, "failed to allocate input device\n");
+ return -ENOMEM;
+ }
+
+ input_set_drvdata(input, st);
+
+ 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_setup_polling(input, adc_keys_poll);
+ if (error) {
+ dev_err(dev, "Unable to set up polling: %d\n", error);
+ return error;
+ }
+
+ if (!device_property_read_u32(dev, "poll-interval", &value))
+ input_set_poll_interval(input, value);
+
+ error = input_register_device(input);
+ 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 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 <alexandre.belloni@free-electrons.com>");
+MODULE_DESCRIPTION("Input driver for resistor ladder connected on ADC");
+MODULE_LICENSE("GPL v2");