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 | 69 +++++++++++++++++++++++++++
 3 files changed, 84 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..6407b2258eb1
--- /dev/null
+++ b/drivers/input/touchscreen/goodix_berlin_i2c.c
@@ -0,0 +1,69 @@
+// 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;
+
+	regmap = devm_regmap_init_i2c(client, &goodix_berlin_i2c_regmap_conf);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	return goodix_berlin_probe(&client->dev, client->irq,
+				   &goodix_berlin_i2c_input_id, regmap);
+}
+
+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

Hi Neil,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 2030579113a1b1b5bfd7ff24c0852847836d8fd1]

url:    https://github.com/intel-lab-lkp/linux/commits/Neil-Armstrong/dt-bindings-input-document-Goodix-Berlin-Touchscreen-IC/20231021-191942
base:   2030579113a1b1b5bfd7ff24c0852847836d8fd1
patch link:    https://lore.kernel.org/r/20231021-topic-goodix-berlin-upstream-initial-v9-3-13fb4e887156%40linaro.org
patch subject: [PATCH v9 3/4] Input: goodix-berlin - add I2C support for Goodix Berlin Touchscreen IC
config: sh-allyesconfig (https://download.01.org/0day-ci/archive/20231023/202310231123.eHyxswnW-lkp@intel.com/config)
compiler: sh4-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231023/202310231123.eHyxswnW-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202310231123.eHyxswnW-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/input/touchscreen/goodix_berlin_core.c: In function 'goodix_berlin_get_ic_info':
>> drivers/input/touchscreen/goodix_berlin_core.c:285:1: warning: the frame size of 1148 bytes is larger than 1024 bytes [-Wframe-larger-than=]
     285 | }
         | ^


vim +285 drivers/input/touchscreen/goodix_berlin_core.c

7aae63b22cf7e9 Neil Armstrong 2023-10-21  235  
7aae63b22cf7e9 Neil Armstrong 2023-10-21  236  static int goodix_berlin_get_ic_info(struct goodix_berlin_core *cd)
7aae63b22cf7e9 Neil Armstrong 2023-10-21  237  {
7aae63b22cf7e9 Neil Armstrong 2023-10-21  238  	u8 afe_data[GOODIX_BERLIN_IC_INFO_MAX_LEN];
7aae63b22cf7e9 Neil Armstrong 2023-10-21  239  	__le16 length_raw;
7aae63b22cf7e9 Neil Armstrong 2023-10-21  240  	u16 length;
7aae63b22cf7e9 Neil Armstrong 2023-10-21  241  	int error;
7aae63b22cf7e9 Neil Armstrong 2023-10-21  242  
7aae63b22cf7e9 Neil Armstrong 2023-10-21  243  	error = regmap_raw_read(cd->regmap, GOODIX_BERLIN_IC_INFO_ADDR,
7aae63b22cf7e9 Neil Armstrong 2023-10-21  244  				&length_raw, sizeof(length_raw));
7aae63b22cf7e9 Neil Armstrong 2023-10-21  245  	if (error) {
7aae63b22cf7e9 Neil Armstrong 2023-10-21  246  		dev_info(cd->dev, "failed get ic info length, %d\n", error);
7aae63b22cf7e9 Neil Armstrong 2023-10-21  247  		return error;
7aae63b22cf7e9 Neil Armstrong 2023-10-21  248  	}
7aae63b22cf7e9 Neil Armstrong 2023-10-21  249  
7aae63b22cf7e9 Neil Armstrong 2023-10-21  250  	length = le16_to_cpu(length_raw);
7aae63b22cf7e9 Neil Armstrong 2023-10-21  251  	if (length >= GOODIX_BERLIN_IC_INFO_MAX_LEN) {
7aae63b22cf7e9 Neil Armstrong 2023-10-21  252  		dev_info(cd->dev, "invalid ic info length %d\n", length);
7aae63b22cf7e9 Neil Armstrong 2023-10-21  253  		return -EINVAL;
7aae63b22cf7e9 Neil Armstrong 2023-10-21  254  	}
7aae63b22cf7e9 Neil Armstrong 2023-10-21  255  
7aae63b22cf7e9 Neil Armstrong 2023-10-21  256  	error = regmap_raw_read(cd->regmap, GOODIX_BERLIN_IC_INFO_ADDR,
7aae63b22cf7e9 Neil Armstrong 2023-10-21  257  				afe_data, length);
7aae63b22cf7e9 Neil Armstrong 2023-10-21  258  	if (error) {
7aae63b22cf7e9 Neil Armstrong 2023-10-21  259  		dev_info(cd->dev, "failed get ic info data, %d\n", error);
7aae63b22cf7e9 Neil Armstrong 2023-10-21  260  		return error;
7aae63b22cf7e9 Neil Armstrong 2023-10-21  261  	}
7aae63b22cf7e9 Neil Armstrong 2023-10-21  262  
7aae63b22cf7e9 Neil Armstrong 2023-10-21  263  	/* check whether the data is valid (ex. bus default values) */
7aae63b22cf7e9 Neil Armstrong 2023-10-21  264  	if (goodix_berlin_is_dummy_data(cd, (const uint8_t *)afe_data, length)) {
7aae63b22cf7e9 Neil Armstrong 2023-10-21  265  		dev_err(cd->dev, "fw info data invalid\n");
7aae63b22cf7e9 Neil Armstrong 2023-10-21  266  		return -EINVAL;
7aae63b22cf7e9 Neil Armstrong 2023-10-21  267  	}
7aae63b22cf7e9 Neil Armstrong 2023-10-21  268  
7aae63b22cf7e9 Neil Armstrong 2023-10-21  269  	if (!goodix_berlin_checksum_valid((const uint8_t *)afe_data, length)) {
7aae63b22cf7e9 Neil Armstrong 2023-10-21  270  		dev_info(cd->dev, "fw info checksum error\n");
7aae63b22cf7e9 Neil Armstrong 2023-10-21  271  		return -EINVAL;
7aae63b22cf7e9 Neil Armstrong 2023-10-21  272  	}
7aae63b22cf7e9 Neil Armstrong 2023-10-21  273  
7aae63b22cf7e9 Neil Armstrong 2023-10-21  274  	error = goodix_berlin_convert_ic_info(cd, afe_data, length);
7aae63b22cf7e9 Neil Armstrong 2023-10-21  275  	if (error)
7aae63b22cf7e9 Neil Armstrong 2023-10-21  276  		return error;
7aae63b22cf7e9 Neil Armstrong 2023-10-21  277  
7aae63b22cf7e9 Neil Armstrong 2023-10-21  278  	/* check some key info */
7aae63b22cf7e9 Neil Armstrong 2023-10-21  279  	if (!cd->touch_data_addr) {
7aae63b22cf7e9 Neil Armstrong 2023-10-21  280  		dev_err(cd->dev, "touch_data_addr is null\n");
7aae63b22cf7e9 Neil Armstrong 2023-10-21  281  		return -EINVAL;
7aae63b22cf7e9 Neil Armstrong 2023-10-21  282  	}
7aae63b22cf7e9 Neil Armstrong 2023-10-21  283  
7aae63b22cf7e9 Neil Armstrong 2023-10-21  284  	return 0;
7aae63b22cf7e9 Neil Armstrong 2023-10-21 @285  }
7aae63b22cf7e9 Neil Armstrong 2023-10-21  286  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki