Goodix i2c-hid touchscreens are mostly i2c-hid compliant but have some
special power sequencing requirements, including the need to drive a
reset line during the sequencing.
Let's use the new rejiggering of i2c-hid to support this with a thin
wrapper driver to support the first Goodix i2c-hid touchscreen:
GT7375P
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---
(no changes since v6)
Changes in v6:
- Suspend/resume are no longer exported from the core.
Changes in v5:
- i2chid_subclass_data => i2chid_ops.
- power_up_device => power_up (same with power_down).
- subclass => ops.
Changes in v4:
- Totally redid based on the new subclass system.
Changes in v3:
- Rework to use subclassing.
drivers/hid/i2c-hid/Kconfig | 19 +++-
drivers/hid/i2c-hid/Makefile | 1 +
drivers/hid/i2c-hid/i2c-hid-of-goodix.c | 116 ++++++++++++++++++++++++
3 files changed, 134 insertions(+), 2 deletions(-)
create mode 100644 drivers/hid/i2c-hid/i2c-hid-of-goodix.c
diff --git a/drivers/hid/i2c-hid/Kconfig b/drivers/hid/i2c-hid/Kconfig
index 819b7521c182..a16c6a69680b 100644
--- a/drivers/hid/i2c-hid/Kconfig
+++ b/drivers/hid/i2c-hid/Kconfig
@@ -32,10 +32,25 @@ config I2C_HID_OF
will be called i2c-hid-of. It will also build/depend on the
module i2c-hid.
+config I2C_HID_OF_GOODIX
+ tristate "Driver for Goodix hid-i2c based devices on OF systems"
+ default n
+ depends on I2C && INPUT && OF
+ help
+ Say Y here if you want support for Goodix i2c devices that use
+ the i2c-hid protocol on Open Firmware (Device Tree)-based
+ systems.
+
+ If unsure, say N.
+
+ This support is also available as a module. If so, the module
+ will be called i2c-hid-of-goodix. It will also build/depend on
+ the module i2c-hid.
+
endmenu
config I2C_HID_CORE
tristate
- default y if I2C_HID_ACPI=y || I2C_HID_OF=y
- default m if I2C_HID_ACPI=m || I2C_HID_OF=m
+ default y if I2C_HID_ACPI=y || I2C_HID_OF=y || I2C_HID_OF_GOODIX=y
+ default m if I2C_HID_ACPI=m || I2C_HID_OF=m || I2C_HID_OF_GOODIX=m
select HID
diff --git a/drivers/hid/i2c-hid/Makefile b/drivers/hid/i2c-hid/Makefile
index 9b4a73446841..302545a771f3 100644
--- a/drivers/hid/i2c-hid/Makefile
+++ b/drivers/hid/i2c-hid/Makefile
@@ -10,3 +10,4 @@ i2c-hid-$(CONFIG_DMI) += i2c-hid-dmi-quirks.o
obj-$(CONFIG_I2C_HID_ACPI) += i2c-hid-acpi.o
obj-$(CONFIG_I2C_HID_OF) += i2c-hid-of.o
+obj-$(CONFIG_I2C_HID_OF_GOODIX) += i2c-hid-of-goodix.o
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 000000000000..7cc51c25c609
--- /dev/null
+++ b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c
@@ -0,0 +1,116 @@
+// 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 gpio_desc *reset_gpio;
+ const struct goodix_i2c_hid_timing_data *timings;
+};
+
+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);
+ int ret;
+
+ ret = regulator_enable(ihid_goodix->vdd);
+ if (ret)
+ return ret;
+
+ if (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);
+
+ return 0;
+}
+
+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);
+
+ gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1);
+ regulator_disable(ihid_goodix->vdd);
+}
+
+static int i2c_hid_of_goodix_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct i2c_hid_of_goodix *ihid_goodix;
+
+ 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);
+
+ return i2c_hid_core_probe(client, &ihid_goodix->ops, 0x0001);
+}
+
+static const struct goodix_i2c_hid_timing_data goodix_gt7375p_timing_data = {
+ .post_power_delay_ms = 10,
+ .post_gpio_reset_delay_ms = 120,
+};
+
+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@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Goodix i2c-hid touchscreen driver");
+MODULE_LICENSE("GPL v2");
--
2.29.2.576.ga3fc446d84-goog
