diff mbox series

[v8,4/4] HID: i2c-hid: Introduce goodix-i2c-hid using i2c-hid core

Message ID 20201211142412.v8.4.If41b7d621633b94d56653c6d53f5f89c5274de7b@changeid (mailing list archive)
State Superseded
Delegated to: Jiri Kosina
Headers show
Series HID: i2c-hid: Reorganize to allow supporting goodix,gt7375p | expand

Commit Message

Doug Anderson Dec. 11, 2020, 10:24 p.m. UTC
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@chromium.org>
---

(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

Comments

Doug Anderson Jan. 6, 2021, 4:44 p.m. UTC | #1
Hi,

On Fri, Dec 11, 2020 at 2:25 PM Douglas Anderson <dianders@chromium.org> wrote:
>
> +static const struct goodix_i2c_hid_timing_data goodix_gt7375p_timing_data = {
> +       .post_power_delay_ms = 10,
> +       .post_gpio_reset_delay_ms = 120,

As I've been going through my holiday email I found that Goodix has
released a new datasheet (datasheet rev 0.6 from 2020-12-11) where
this moves from 120 ms to 180 ms.  Sigh.

I'm hoping that we can just land it with the 120 though and then I'll
send a follow-up patch to change to 180.  This will avoid spamming
everyone with a v9 of the patch series.  Please yell if there are any
objections to that plan.  I'd also be fine if you wanted to just
change it to 180 when landing it.

Thanks much!

-Doug
diff mbox series

Patch

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@chromium.org>");
+MODULE_DESCRIPTION("Goodix i2c-hid touchscreen driver");
+MODULE_LICENSE("GPL v2");