ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/drivers/input/misc/rotary_encoder.c b/marvell/linux/drivers/input/misc/rotary_encoder.c
new file mode 100644
index 0000000..6d613f2
--- /dev/null
+++ b/marvell/linux/drivers/input/misc/rotary_encoder.c
@@ -0,0 +1,370 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * rotary_encoder.c
+ *
+ * (c) 2009 Daniel Mack <daniel@caiaq.de>
+ * Copyright (C) 2011 Johan Hovold <jhovold@gmail.com>
+ *
+ * state machine code inspired by code from Tim Ruetz
+ *
+ * A generic driver for rotary encoders connected to GPIO lines.
+ * See file:Documentation/input/devices/rotary-encoder.rst for more information
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/input.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/property.h>
+
+#define DRV_NAME "rotary-encoder"
+
+enum rotary_encoder_encoding {
+ ROTENC_GRAY,
+ ROTENC_BINARY,
+};
+
+struct rotary_encoder {
+ struct input_dev *input;
+
+ struct mutex access_mutex;
+
+ u32 steps;
+ u32 axis;
+ bool relative_axis;
+ bool rollover;
+ enum rotary_encoder_encoding encoding;
+
+ unsigned int pos;
+
+ struct gpio_descs *gpios;
+
+ unsigned int *irq;
+
+ bool armed;
+ signed char dir; /* 1 - clockwise, -1 - CCW */
+
+ unsigned int last_stable;
+};
+
+static unsigned int rotary_encoder_get_state(struct rotary_encoder *encoder)
+{
+ int i;
+ unsigned int ret = 0;
+
+ for (i = 0; i < encoder->gpios->ndescs; ++i) {
+ int val = gpiod_get_value_cansleep(encoder->gpios->desc[i]);
+
+ /* convert from gray encoding to normal */
+ if (encoder->encoding == ROTENC_GRAY && ret & 1)
+ val = !val;
+
+ ret = ret << 1 | val;
+ }
+
+ return ret & 3;
+}
+
+static void rotary_encoder_report_event(struct rotary_encoder *encoder)
+{
+ if (encoder->relative_axis) {
+ input_report_rel(encoder->input,
+ encoder->axis, encoder->dir);
+ } else {
+ unsigned int pos = encoder->pos;
+
+ if (encoder->dir < 0) {
+ /* turning counter-clockwise */
+ if (encoder->rollover)
+ pos += encoder->steps;
+ if (pos)
+ pos--;
+ } else {
+ /* turning clockwise */
+ if (encoder->rollover || pos < encoder->steps)
+ pos++;
+ }
+
+ if (encoder->rollover)
+ pos %= encoder->steps;
+
+ encoder->pos = pos;
+ input_report_abs(encoder->input, encoder->axis, encoder->pos);
+ }
+
+ input_sync(encoder->input);
+}
+
+static irqreturn_t rotary_encoder_irq(int irq, void *dev_id)
+{
+ struct rotary_encoder *encoder = dev_id;
+ unsigned int state;
+
+ mutex_lock(&encoder->access_mutex);
+
+ state = rotary_encoder_get_state(encoder);
+
+ switch (state) {
+ case 0x0:
+ if (encoder->armed) {
+ rotary_encoder_report_event(encoder);
+ encoder->armed = false;
+ }
+ break;
+
+ case 0x1:
+ case 0x3:
+ if (encoder->armed)
+ encoder->dir = 2 - state;
+ break;
+
+ case 0x2:
+ encoder->armed = true;
+ break;
+ }
+
+ mutex_unlock(&encoder->access_mutex);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id)
+{
+ struct rotary_encoder *encoder = dev_id;
+ unsigned int state;
+
+ mutex_lock(&encoder->access_mutex);
+
+ state = rotary_encoder_get_state(encoder);
+
+ if (state & 1) {
+ encoder->dir = ((encoder->last_stable - state + 1) % 4) - 1;
+ } else {
+ if (state != encoder->last_stable) {
+ rotary_encoder_report_event(encoder);
+ encoder->last_stable = state;
+ }
+ }
+
+ mutex_unlock(&encoder->access_mutex);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t rotary_encoder_quarter_period_irq(int irq, void *dev_id)
+{
+ struct rotary_encoder *encoder = dev_id;
+ unsigned int state;
+
+ mutex_lock(&encoder->access_mutex);
+
+ state = rotary_encoder_get_state(encoder);
+
+ if ((encoder->last_stable + 1) % 4 == state)
+ encoder->dir = 1;
+ else if (encoder->last_stable == (state + 1) % 4)
+ encoder->dir = -1;
+ else
+ goto out;
+
+ rotary_encoder_report_event(encoder);
+
+out:
+ encoder->last_stable = state;
+ mutex_unlock(&encoder->access_mutex);
+
+ return IRQ_HANDLED;
+}
+
+static int rotary_encoder_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rotary_encoder *encoder;
+ struct input_dev *input;
+ irq_handler_t handler;
+ u32 steps_per_period;
+ unsigned int i;
+ int err;
+
+ encoder = devm_kzalloc(dev, sizeof(struct rotary_encoder), GFP_KERNEL);
+ if (!encoder)
+ return -ENOMEM;
+
+ mutex_init(&encoder->access_mutex);
+
+ device_property_read_u32(dev, "rotary-encoder,steps", &encoder->steps);
+
+ err = device_property_read_u32(dev, "rotary-encoder,steps-per-period",
+ &steps_per_period);
+ if (err) {
+ /*
+ * The 'half-period' property has been deprecated, you must
+ * use 'steps-per-period' and set an appropriate value, but
+ * we still need to parse it to maintain compatibility. If
+ * neither property is present we fall back to the one step
+ * per period behavior.
+ */
+ steps_per_period = device_property_read_bool(dev,
+ "rotary-encoder,half-period") ? 2 : 1;
+ }
+
+ encoder->rollover =
+ device_property_read_bool(dev, "rotary-encoder,rollover");
+
+ if (!device_property_present(dev, "rotary-encoder,encoding") ||
+ !device_property_match_string(dev, "rotary-encoder,encoding",
+ "gray")) {
+ dev_info(dev, "gray");
+ encoder->encoding = ROTENC_GRAY;
+ } else if (!device_property_match_string(dev, "rotary-encoder,encoding",
+ "binary")) {
+ dev_info(dev, "binary");
+ encoder->encoding = ROTENC_BINARY;
+ } else {
+ dev_err(dev, "unknown encoding setting\n");
+ return -EINVAL;
+ }
+
+ device_property_read_u32(dev, "linux,axis", &encoder->axis);
+ encoder->relative_axis =
+ device_property_read_bool(dev, "rotary-encoder,relative-axis");
+
+ encoder->gpios = devm_gpiod_get_array(dev, NULL, GPIOD_IN);
+ if (IS_ERR(encoder->gpios)) {
+ err = PTR_ERR(encoder->gpios);
+ if (err != -EPROBE_DEFER)
+ dev_err(dev, "unable to get gpios: %d\n", err);
+ return err;
+ }
+ if (encoder->gpios->ndescs < 2) {
+ dev_err(dev, "not enough gpios found\n");
+ return -EINVAL;
+ }
+
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return -ENOMEM;
+
+ encoder->input = input;
+
+ input->name = pdev->name;
+ input->id.bustype = BUS_HOST;
+ input->dev.parent = dev;
+
+ if (encoder->relative_axis)
+ input_set_capability(input, EV_REL, encoder->axis);
+ else
+ input_set_abs_params(input,
+ encoder->axis, 0, encoder->steps, 0, 1);
+
+ switch (steps_per_period >> (encoder->gpios->ndescs - 2)) {
+ case 4:
+ handler = &rotary_encoder_quarter_period_irq;
+ encoder->last_stable = rotary_encoder_get_state(encoder);
+ break;
+ case 2:
+ handler = &rotary_encoder_half_period_irq;
+ encoder->last_stable = rotary_encoder_get_state(encoder);
+ break;
+ case 1:
+ handler = &rotary_encoder_irq;
+ break;
+ default:
+ dev_err(dev, "'%d' is not a valid steps-per-period value\n",
+ steps_per_period);
+ return -EINVAL;
+ }
+
+ encoder->irq =
+ devm_kcalloc(dev,
+ encoder->gpios->ndescs, sizeof(*encoder->irq),
+ GFP_KERNEL);
+ if (!encoder->irq)
+ return -ENOMEM;
+
+ for (i = 0; i < encoder->gpios->ndescs; ++i) {
+ encoder->irq[i] = gpiod_to_irq(encoder->gpios->desc[i]);
+
+ err = devm_request_threaded_irq(dev, encoder->irq[i],
+ NULL, handler,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
+ IRQF_ONESHOT,
+ DRV_NAME, encoder);
+ if (err) {
+ dev_err(dev, "unable to request IRQ %d (gpio#%d)\n",
+ encoder->irq[i], i);
+ return err;
+ }
+ }
+
+ err = input_register_device(input);
+ if (err) {
+ dev_err(dev, "failed to register input device\n");
+ return err;
+ }
+
+ device_init_wakeup(dev,
+ device_property_read_bool(dev, "wakeup-source"));
+
+ platform_set_drvdata(pdev, encoder);
+
+ return 0;
+}
+
+static int __maybe_unused rotary_encoder_suspend(struct device *dev)
+{
+ struct rotary_encoder *encoder = dev_get_drvdata(dev);
+ unsigned int i;
+
+ if (device_may_wakeup(dev)) {
+ for (i = 0; i < encoder->gpios->ndescs; ++i)
+ enable_irq_wake(encoder->irq[i]);
+ }
+
+ return 0;
+}
+
+static int __maybe_unused rotary_encoder_resume(struct device *dev)
+{
+ struct rotary_encoder *encoder = dev_get_drvdata(dev);
+ unsigned int i;
+
+ if (device_may_wakeup(dev)) {
+ for (i = 0; i < encoder->gpios->ndescs; ++i)
+ disable_irq_wake(encoder->irq[i]);
+ }
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(rotary_encoder_pm_ops,
+ rotary_encoder_suspend, rotary_encoder_resume);
+
+#ifdef CONFIG_OF
+static const struct of_device_id rotary_encoder_of_match[] = {
+ { .compatible = "rotary-encoder", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, rotary_encoder_of_match);
+#endif
+
+static struct platform_driver rotary_encoder_driver = {
+ .probe = rotary_encoder_probe,
+ .driver = {
+ .name = DRV_NAME,
+ .pm = &rotary_encoder_pm_ops,
+ .of_match_table = of_match_ptr(rotary_encoder_of_match),
+ }
+};
+module_platform_driver(rotary_encoder_driver);
+
+MODULE_ALIAS("platform:" DRV_NAME);
+MODULE_DESCRIPTION("GPIO rotary encoder driver");
+MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>, Johan Hovold");
+MODULE_LICENSE("GPL v2");