Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 178 insertions, 0 deletions

diff --git a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c
new file mode 100644
index 000000000..ec6c73f75
--- /dev/null
+++ b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Goodix touchscreens that use the i2c-hid protocol.
+ *
+ * Copyright 2020 Google LLC
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/regulator/consumer.h>
+
+#include "i2c-hid.h"
+
+struct goodix_i2c_hid_timing_data {
+	unsigned int post_gpio_reset_delay_ms;
+	unsigned int post_power_delay_ms;
+};
+
+struct i2c_hid_of_goodix {
+	struct i2chid_ops ops;
+
+	struct regulator *vdd;
+	struct notifier_block nb;
+	struct gpio_desc *reset_gpio;
+	const struct goodix_i2c_hid_timing_data *timings;
+};
+
+static void goodix_i2c_hid_deassert_reset(struct i2c_hid_of_goodix *ihid_goodix,
+					  bool regulator_just_turned_on)
+{
+	if (regulator_just_turned_on && ihid_goodix->timings->post_power_delay_ms)
+		msleep(ihid_goodix->timings->post_power_delay_ms);
+
+	gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 0);
+	if (ihid_goodix->timings->post_gpio_reset_delay_ms)
+		msleep(ihid_goodix->timings->post_gpio_reset_delay_ms);
+}
+
+static int goodix_i2c_hid_power_up(struct i2chid_ops *ops)
+{
+	struct i2c_hid_of_goodix *ihid_goodix =
+		container_of(ops, struct i2c_hid_of_goodix, ops);
+
+	return regulator_enable(ihid_goodix->vdd);
+}
+
+static void goodix_i2c_hid_power_down(struct i2chid_ops *ops)
+{
+	struct i2c_hid_of_goodix *ihid_goodix =
+		container_of(ops, struct i2c_hid_of_goodix, ops);
+
+	regulator_disable(ihid_goodix->vdd);
+}
+
+static int ihid_goodix_vdd_notify(struct notifier_block *nb,
+				    unsigned long event,
+				    void *ignored)
+{
+	struct i2c_hid_of_goodix *ihid_goodix =
+		container_of(nb, struct i2c_hid_of_goodix, nb);
+	int ret = NOTIFY_OK;
+
+	switch (event) {
+	case REGULATOR_EVENT_PRE_DISABLE:
+		gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1);
+		break;
+
+	case REGULATOR_EVENT_ENABLE:
+		goodix_i2c_hid_deassert_reset(ihid_goodix, true);
+		break;
+
+	case REGULATOR_EVENT_ABORT_DISABLE:
+		goodix_i2c_hid_deassert_reset(ihid_goodix, false);
+		break;
+
+	default:
+		ret = NOTIFY_DONE;
+		break;
+	}
+
+	return ret;
+}
+
+static int i2c_hid_of_goodix_probe(struct i2c_client *client,
+				   const struct i2c_device_id *id)
+{
+	struct i2c_hid_of_goodix *ihid_goodix;
+	int ret;
+	ihid_goodix = devm_kzalloc(&client->dev, sizeof(*ihid_goodix),
+				   GFP_KERNEL);
+	if (!ihid_goodix)
+		return -ENOMEM;
+
+	ihid_goodix->ops.power_up = goodix_i2c_hid_power_up;
+	ihid_goodix->ops.power_down = goodix_i2c_hid_power_down;
+
+	/* Start out with reset asserted */
+	ihid_goodix->reset_gpio =
+		devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(ihid_goodix->reset_gpio))
+		return PTR_ERR(ihid_goodix->reset_gpio);
+
+	ihid_goodix->vdd = devm_regulator_get(&client->dev, "vdd");
+	if (IS_ERR(ihid_goodix->vdd))
+		return PTR_ERR(ihid_goodix->vdd);
+
+	ihid_goodix->timings = device_get_match_data(&client->dev);
+
+	/*
+	 * We need to control the "reset" line in lockstep with the regulator
+	 * actually turning on an off instead of just when we make the request.
+	 * This matters if the regulator is shared with another consumer.
+	 * - If the regulator is off then we must assert reset. The reset
+	 *   line is active low and on some boards it could cause a current
+	 *   leak if left high.
+	 * - If the regulator is on then we don't want reset asserted for very
+	 *   long. Holding the controller in reset apparently draws extra
+	 *   power.
+	 */
+	ihid_goodix->nb.notifier_call = ihid_goodix_vdd_notify;
+	ret = devm_regulator_register_notifier(ihid_goodix->vdd, &ihid_goodix->nb);
+	if (ret)
+		return dev_err_probe(&client->dev, ret,
+			"regulator notifier request failed\n");
+
+	/*
+	 * If someone else is holding the regulator on (or the regulator is
+	 * an always-on one) we might never be told to deassert reset. Do it
+	 * now... and temporarily bump the regulator reference count just to
+	 * make sure it is impossible for this to race with our own notifier!
+	 * We also assume that someone else might have _just barely_ turned
+	 * the regulator on so we'll do the full "post_power_delay" just in
+	 * case.
+	 */
+	if (ihid_goodix->reset_gpio && regulator_is_enabled(ihid_goodix->vdd)) {
+		ret = regulator_enable(ihid_goodix->vdd);
+		if (ret)
+			return ret;
+		goodix_i2c_hid_deassert_reset(ihid_goodix, true);
+		regulator_disable(ihid_goodix->vdd);
+	}
+
+	return i2c_hid_core_probe(client, &ihid_goodix->ops, 0x0001, 0);
+}
+
+static const struct goodix_i2c_hid_timing_data goodix_gt7375p_timing_data = {
+	.post_power_delay_ms = 10,
+	.post_gpio_reset_delay_ms = 180,
+};
+
+static const struct of_device_id goodix_i2c_hid_of_match[] = {
+	{ .compatible = "goodix,gt7375p", .data = &goodix_gt7375p_timing_data },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, goodix_i2c_hid_of_match);
+
+static struct i2c_driver goodix_i2c_hid_ts_driver = {
+	.driver = {
+		.name	= "i2c_hid_of_goodix",
+		.pm	= &i2c_hid_core_pm,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = of_match_ptr(goodix_i2c_hid_of_match),
+	},
+	.probe		= i2c_hid_of_goodix_probe,
+	.remove		= i2c_hid_core_remove,
+	.shutdown	= i2c_hid_core_shutdown,
+};
+module_i2c_driver(goodix_i2c_hid_ts_driver);
+
+MODULE_AUTHOR("Douglas Anderson <dianders@chromium.org>");
+MODULE_DESCRIPTION("Goodix i2c-hid touchscreen driver");
+MODULE_LICENSE("GPL v2");