[PATCH v12 3/4] Input: goodix-berlin - add I2C support for Goodix Berlin Touchscreen IC

Neil Armstrong
2023-12-09T07:34:04Z

Add initial support for the new Goodix "Berlin" touchscreen ICs
over the I2C interface.

This initial driver is derived from the Goodix goodix_ts_berlin
available at [1] and [2] and only supports the GT9916 IC
present on the Qualcomm SM8550 MTP & QRD touch panel.

The current implementation only supports BerlinD, aka GT9916.

[1] https://github.com/goodix/goodix_ts_berlin
[2] https://git.codelinaro.org/clo/la/platform/vendor/opensource/touch-drivers

Reviewed-by: Jeff LaBundy <jeff@labundy.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
drivers/input/touchscreen/Kconfig | 14 +++++
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/goodix_berlin_i2c.c | 74 +++++++++++++++++++++++++++
3 files changed, 89 insertions(+)

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 950da599ae1a..cc7b88118158 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -419,6 +419,20 @@ config TOUCHSCREEN_GOODIX
config TOUCHSCREEN_GOODIX_BERLIN_CORE
tristate

+config TOUCHSCREEN_GOODIX_BERLIN_I2C
+ tristate "Goodix Berlin I2C touchscreen"
+ depends on I2C
+ select REGMAP_I2C
+ select TOUCHSCREEN_GOODIX_BERLIN_CORE
+ help
+ Say Y here if you have a Goodix Berlin IC connected to
+ your system via I2C.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the
+ module will be called goodix_berlin_i2c.
+
config TOUCHSCREEN_HIDEEP
tristate "HiDeep Touch IC"
depends on I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 2e2f3e70cd2c..7ef677cf7a10 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_TOUCHSCREEN_EXC3000) += exc3000.o
obj-$(CONFIG_TOUCHSCREEN_FUJITSU) += fujitsu_ts.o
obj-$(CONFIG_TOUCHSCREEN_GOODIX) += goodix_ts.o
obj-$(CONFIG_TOUCHSCREEN_GOODIX_BERLIN_CORE) += goodix_berlin_core.o
+obj-$(CONFIG_TOUCHSCREEN_GOODIX_BERLIN_I2C) += goodix_berlin_i2c.o
obj-$(CONFIG_TOUCHSCREEN_HIDEEP) += hideep.o
obj-$(CONFIG_TOUCHSCREEN_HYNITRON_CSTXXX) += hynitron_cstxxx.o
obj-$(CONFIG_TOUCHSCREEN_ILI210X) += ili210x.o
diff --git a/drivers/input/touchscreen/goodix_berlin_i2c.c b/drivers/input/touchscreen/goodix_berlin_i2c.c
new file mode 100644
index 000000000000..4d5bcc101569
--- /dev/null
+++ b/drivers/input/touchscreen/goodix_berlin_i2c.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Goodix Berlin Touchscreen Driver
+ *
+ * Copyright (C) 2020 - 2021 Goodix, Inc.
+ * Copyright (C) 2023 Linaro Ltd.
+ *
+ * Based on goodix_ts_berlin driver.
+ */
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include "goodix_berlin.h"
+
+#define I2C_MAX_TRANSFER_SIZE 256
+
+static const struct regmap_config goodix_berlin_i2c_regmap_conf = {
+ .reg_bits = 32,
+ .val_bits = 8,
+ .max_raw_read = I2C_MAX_TRANSFER_SIZE,
+ .max_raw_write = I2C_MAX_TRANSFER_SIZE,
+};
+
+/* vendor & product left unassigned here, should probably be updated from fw info */
+static const struct input_id goodix_berlin_i2c_input_id = {
+ .bustype = BUS_I2C,
+};
+
+static int goodix_berlin_i2c_probe(struct i2c_client *client)
+{
+ struct regmap *regmap;
+ int error;
+
+ regmap = devm_regmap_init_i2c(client, &goodix_berlin_i2c_regmap_conf);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ error = goodix_berlin_probe(&client->dev, client->irq,
+ &goodix_berlin_i2c_input_id, regmap);
+ if (error)
+ return error;
+
+ return 0;
+}
+
+static const struct i2c_device_id goodix_berlin_i2c_id[] = {
+ { "gt9916", 0 },
+ { }
+};
+
+MODULE_DEVICE_TABLE(i2c, goodix_berlin_i2c_id);
+
+static const struct of_device_id goodix_berlin_i2c_of_match[] = {
+ { .compatible = "goodix,gt9916", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, goodix_berlin_i2c_of_match);
+
+static struct i2c_driver goodix_berlin_i2c_driver = {
+ .driver = {
+ .name = "goodix-berlin-i2c",
+ .of_match_table = goodix_berlin_i2c_of_match,
+ .pm = pm_sleep_ptr(&goodix_berlin_pm_ops),
+ },
+ .probe = goodix_berlin_i2c_probe,
+ .id_table = goodix_berlin_i2c_id,
+};
+module_i2c_driver(goodix_berlin_i2c_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Goodix Berlin I2C Touchscreen driver");
+MODULE_AUTHOR("Neil Armstrong <neil.armstrong@linaro.org>");

--
2.34.1