[PATCH v14 0/4] Input: add initial support for Goodix Berlin touchscreen IC

[PATCH v14 0/4] Input: add initial support for Goodix Berlin touchscreen IC

[Neil Armstrong]

These touchscreen ICs support SPI, I2C and I3C interface, up to
10 finger touch, stylus and gestures events.

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/SM8650 MTP & QRD touch panel.

The current implementation only supports BerlinD, aka GT9916.

Support for advanced features like:
- Firmware & config update
- Stylus events
- Gestures events
- Previous revisions support (BerlinA or BerlinB)
is not included in current version.

The current support will work with currently flashed firmware
and config, and bail out if firmware or config aren't flashed yet.

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

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
Changes in v14:
- Rebased on next-20231221
- Fixed build on SPI/I2S drivers missing <linux/input.h> include
- Link to v13: https://lore.kernel.org/r/20231213-topic-goodix-berlin-upstream-initial-v13-0-5d7a26a5eaa2@linaro.org

Changes in v13:
- Thanks to Dmitry's suggestion:
  - Move core defines and structs into goodix_berlin_core.c
  - Comments typos and rephrasings
  - Identation fixes
  - Refactor of goodix_berlin_power_on
  - goodix_berlin_get_ic_info move to __free(kfree) to avoid leaking
- Added comment explaining how data is retrieved in irq handler
- Link to v12: https://lore.kernel.org/r/20231209-topic-goodix-berlin-upstream-initial-v12-0-eaffaeb53fb5@linaro.org

Changes in v12:
- Rebased on next-20231208
- Link to v11: https://lore.kernel.org/r/20231106-topic-goodix-berlin-upstream-initial-v11-0-5c47e9707c03@linaro.org

Changes in v11:
- Fixes according to Jeff's review:
 - s/dev_info/dev_err/ in goodix_berlin_get_ic_info()
 - remove spurious return instead of goto in goodix_berlin_get_ic_info()
 - added back dropped msleep() in goodix_berlin_request_handle_reset()
- Link to v10: https://lore.kernel.org/r/20231023-topic-goodix-berlin-upstream-initial-v10-0-88eec2e51c0b@linaro.org

Changes in v10:
- Fix according to Dmitry's review:
 - move goodix_berlin_get_ic_info() afe_data to heap
 - merge the goodix_berlin_parse_finger() loops and skip invalid fingers instead of returning
 - remove unwanted goodix_berlin_touch_handler() "static" for buffer
 - only call goodix_berlin_request_handle_reset() if gpio was provided
 - use "error = func(); if(error) return error;" instead of "return func()" when function handles multiple error cases
- Link to v9: https://lore.kernel.org/r/20231021-topic-goodix-berlin-upstream-initial-v9-0-13fb4e887156@linaro.org

Changes in v9:
- Rebased on next-20231020 
- Link to v8: https://lore.kernel.org/r/20231003-topic-goodix-berlin-upstream-initial-v8-0-171606102ed6@linaro.org

Changes in v8:
- Add missing bitfield.h include in core
- Link to v7: https://lore.kernel.org/r/20231002-topic-goodix-berlin-upstream-initial-v7-0-792fb91f5e88@linaro.org

Changes in v7:
- rebased on v6.6-rc3
- Link to v6: https://lore.kernel.org/r/20230912-topic-goodix-berlin-upstream-initial-v6-0-b4ecfa49fb9d@linaro.org

Changes in v6:
- rebased on v6.6-rc1
- changed commit message prefix to match the other Input commits
- Link to v5: https://lore.kernel.org/r/20230801-topic-goodix-berlin-upstream-initial-v5-0-079252935593@linaro.org

Changes in v5:
- rebased on next-20230801
- Link to v4: https://lore.kernel.org/r/20230606-topic-goodix-berlin-upstream-initial-v4-0-0947c489be17@linaro.org

Changes in v4:
- Core updates:
 - drop kconfig depends, deps will be handled by _SPI and _I2C
 - change power_on() error labels
 - print errors on all dev_err() prints
 - remove useless default variable initialization
 - switch irq touch checksum error to dev_err()
 - add Jeff's review tag
- I2C changes
 - change REGMAP_I2C Kconfig from depends to select
 - add Jeff's review tag
- SPI changes
 - add select REGMAP to Kconfig
 - added GOODIX_BERLIN_ prefix to defines
 - switched from ret to error
 - add Jeff's review tag
- Link to v3: https://lore.kernel.org/r/20230606-topic-goodix-berlin-upstream-initial-v3-0-f0577cead709@linaro.org

Changes in v3:
- Another guge cleanups after Jeff's review:
 - appended goodix_berlin_ before all defines
 - removed some unused defines
 - removed retries on most of read functions, can be added back later
 - added __le to ic_info structures
 - reworked and simplified irq handling, dropped enum and ts_event structs
 - added struct for touch data
 - simplified and cleaned goodix_berlin_check_checksum & goodix_berlin_is_dummy_data
 - moved touch_data_addr to the end of the main code_data
 - reworked probe to get_irq last and right before setip input device
 - cleaned probe by removing the "cd->dev"
 - added short paragraph to justify new driver for berlin devices
 - defined all offsets & masks
- Added bindings review tag
- Link to v2: https://lore.kernel.org/r/20230606-topic-goodix-berlin-upstream-initial-v2-0-26bc8fe1e90e@linaro.org

Changes in v2:
- Huge cleanups after Jeff's review:
 - switch to error instead of ret
 - drop dummy vendor/product ids
 - drop unused defined/enums
 - drop unused ic_info and only keep needes values
 - cleanup namings and use goodix_berlin_ everywhere
 - fix regulator setup
 - fix default variables value when assigned afterwars
 - removed indirections
 - dropped debugfs
 - cleaned input_dev setup
 - dropped _remove()
 - sync'ed i2c and spi drivers
- fixed yaml bindings
- Link to v1: https://lore.kernel.org/r/20230606-topic-goodix-berlin-upstream-initial-v1-0-4a0741b8aefd@linaro.org

---
Neil Armstrong (4):
      dt-bindings: input: document Goodix Berlin Touchscreen IC
      Input: add core support for Goodix Berlin Touchscreen IC
      Input: goodix-berlin - add I2C support for Goodix Berlin Touchscreen IC
      Input: goodix-berlin - add SPI support for Goodix Berlin Touchscreen IC

 .../bindings/input/touchscreen/goodix,gt9916.yaml  |  95 +++
 drivers/input/touchscreen/Kconfig                  |  31 +
 drivers/input/touchscreen/Makefile                 |   3 +
 drivers/input/touchscreen/goodix_berlin.h          |  24 +
 drivers/input/touchscreen/goodix_berlin_core.c     | 766 +++++++++++++++++++++
 drivers/input/touchscreen/goodix_berlin_i2c.c      |  75 ++
 drivers/input/touchscreen/goodix_berlin_spi.c      | 178 +++++
 7 files changed, 1172 insertions(+)
---
base-commit: 857647efa9be89a13cf8963c7e167fab062b28bb
change-id: 20230606-topic-goodix-berlin-upstream-initial-ba97e8ec8f4c

Best regards,
-- 
Neil Armstrong <neil.armstrong@linaro.org>

[PATCH v14 1/4] dt-bindings: input: document Goodix Berlin Touchscreen IC

[Neil Armstrong]

Document the Goodix GT9916 wich is part of the "Berlin" serie
of Touchscreen controllers IC from Goodix.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 .../bindings/input/touchscreen/goodix,gt9916.yaml  | 95 ++++++++++++++++++++++
 1 file changed, 95 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/touchscreen/goodix,gt9916.yaml b/Documentation/devicetree/bindings/input/touchscreen/goodix,gt9916.yaml
new file mode 100644
index 000000000000..d90f045ac06c
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/goodix,gt9916.yaml
@@ -0,0 +1,95 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/touchscreen/goodix,gt9916.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Goodix Berlin series touchscreen controller
+
+description: The Goodix Berlin series of touchscreen controllers
+  be connected to either I2C or SPI buses.
+
+maintainers:
+  - Neil Armstrong <neil.armstrong@linaro.org>
+
+allOf:
+  - $ref: touchscreen.yaml#
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - goodix,gt9916
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  reset-gpios:
+    maxItems: 1
+
+  avdd-supply:
+    description: Analog power supply regulator on AVDD pin
+
+  vddio-supply:
+    description: power supply regulator on VDDIO pin
+
+  spi-max-frequency: true
+  touchscreen-inverted-x: true
+  touchscreen-inverted-y: true
+  touchscreen-size-x: true
+  touchscreen-size-y: true
+  touchscreen-swapped-x-y: true
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - avdd-supply
+  - touchscreen-size-x
+  - touchscreen-size-y
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      touchscreen@5d {
+        compatible = "goodix,gt9916";
+        reg = <0x5d>;
+        interrupt-parent = <&gpio>;
+        interrupts = <25 IRQ_TYPE_LEVEL_LOW>;
+        reset-gpios = <&gpio1 1 GPIO_ACTIVE_LOW>;
+        avdd-supply = <&ts_avdd>;
+        touchscreen-size-x = <1024>;
+        touchscreen-size-y = <768>;
+      };
+    };
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      num-cs = <1>;
+      cs-gpios = <&gpio 2 GPIO_ACTIVE_HIGH>;
+      touchscreen@0 {
+        compatible = "goodix,gt9916";
+        reg = <0>;
+        interrupt-parent = <&gpio>;
+        interrupts = <25 IRQ_TYPE_LEVEL_LOW>;
+        reset-gpios = <&gpio1 1 GPIO_ACTIVE_LOW>;
+        avdd-supply = <&ts_avdd>;
+        spi-max-frequency = <1000000>;
+        touchscreen-size-x = <1024>;
+        touchscreen-size-y = <768>;
+      };
+    };
+
+...

-- 
2.34.1

[PATCH v14 2/4] Input: add core support for Goodix Berlin Touchscreen IC

[Neil Armstrong]

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

These touchscreen ICs support SPI, I2C and I3C interface, up to
10 finger touch, stylus and gestures events.

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.

Support for advanced features like:
- Firmware & config update
- Stylus events
- Gestures events
- Previous revisions support (BerlinA or BerlinB)
is not included in current version.

The current support will work with currently flashed firmware
and config, and bail out if firmware or config aren't flashed yet.

[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              |   3 +
 drivers/input/touchscreen/Makefile             |   1 +
 drivers/input/touchscreen/goodix_berlin.h      |  24 +
 drivers/input/touchscreen/goodix_berlin_core.c | 766 +++++++++++++++++++++++++
 4 files changed, 794 insertions(+)

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index e3e2324547b9..950da599ae1a 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -416,6 +416,9 @@ config TOUCHSCREEN_GOODIX
 	  To compile this driver as a module, choose M here: the
 	  module will be called goodix.
 
+config TOUCHSCREEN_GOODIX_BERLIN_CORE
+	tristate
+
 config TOUCHSCREEN_HIDEEP
 	tristate "HiDeep Touch IC"
 	depends on I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 62bd24f3ac8e..2e2f3e70cd2c 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_TOUCHSCREEN_EGALAX_SERIAL)	+= egalax_ts_serial.o
 obj-$(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_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.h b/drivers/input/touchscreen/goodix_berlin.h
new file mode 100644
index 000000000000..1fd77eb69c9a
--- /dev/null
+++ b/drivers/input/touchscreen/goodix_berlin.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Goodix Touchscreen Driver
+ * Copyright (C) 2020 - 2021 Goodix, Inc.
+ * Copyright (C) 2023 Linaro Ltd.
+ *
+ * Based on goodix_berlin_berlin driver.
+ */
+
+#ifndef __GOODIX_BERLIN_H_
+#define __GOODIX_BERLIN_H_
+
+#include <linux/pm.h>
+
+struct device;
+struct input_id;
+struct regmap;
+
+int goodix_berlin_probe(struct device *dev, int irq, const struct input_id *id,
+			struct regmap *regmap);
+
+extern const struct dev_pm_ops goodix_berlin_pm_ops;
+
+#endif
diff --git a/drivers/input/touchscreen/goodix_berlin_core.c b/drivers/input/touchscreen/goodix_berlin_core.c
new file mode 100644
index 000000000000..6aca57e6b5d6
--- /dev/null
+++ b/drivers/input/touchscreen/goodix_berlin_core.c
@@ -0,0 +1,766 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Goodix "Berlin" Touchscreen IC driver
+ * Copyright (C) 2020 - 2021 Goodix, Inc.
+ * Copyright (C) 2023 Linaro Ltd.
+ *
+ * Based on goodix_ts_berlin driver.
+ *
+ * This driver is distinct from goodix.c since hardware interface
+ * is different enough to require a new driver.
+ * None of the register address or data structure are close enough
+ * to the previous generations.
+ *
+ * Currently the driver only handles Multitouch events with already
+ * programmed firmware and "config" for "Revision D" Berlin IC.
+ *
+ * Support is missing for:
+ * - ESD Management
+ * - Firmware update/flashing
+ * - "Config" update/flashing
+ * - Stylus Events
+ * - Gesture Events
+ * - Support for older revisions (A & B)
+ */
+
+#include <linux/bitfield.h>
+#include <linux/gpio/consumer.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/sizes.h>
+#include <asm/unaligned.h>
+
+#include "goodix_berlin.h"
+
+#define GOODIX_BERLIN_MAX_TOUCH			10
+
+#define GOODIX_BERLIN_NORMAL_RESET_DELAY_MS	100
+
+#define GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN	8
+#define GOODIX_BERLIN_STATUS_OFFSET		0
+#define GOODIX_BERLIN_REQUEST_TYPE_OFFSET	2
+
+#define GOODIX_BERLIN_BYTES_PER_POINT		8
+#define GOODIX_BERLIN_COOR_DATA_CHECKSUM_SIZE	2
+#define GOODIX_BERLIN_COOR_DATA_CHECKSUM_MASK	GENMASK(15, 0)
+
+/* Read n finger events */
+#define GOODIX_BERLIN_IRQ_READ_LEN(n)		(GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN + \
+						 (GOODIX_BERLIN_BYTES_PER_POINT * (n)) + \
+						 GOODIX_BERLIN_COOR_DATA_CHECKSUM_SIZE)
+
+#define GOODIX_BERLIN_TOUCH_EVENT		BIT(7)
+#define GOODIX_BERLIN_REQUEST_EVENT		BIT(6)
+#define GOODIX_BERLIN_TOUCH_COUNT_MASK		GENMASK(3, 0)
+
+#define GOODIX_BERLIN_REQUEST_CODE_RESET	3
+
+#define GOODIX_BERLIN_POINT_TYPE_MASK		GENMASK(3, 0)
+#define GOODIX_BERLIN_POINT_TYPE_STYLUS_HOVER	1
+#define GOODIX_BERLIN_POINT_TYPE_STYLUS		3
+
+#define GOODIX_BERLIN_TOUCH_ID_MASK		GENMASK(7, 4)
+
+#define GOODIX_BERLIN_DEV_CONFIRM_VAL		0xAA
+#define GOODIX_BERLIN_BOOTOPTION_ADDR		0x10000
+#define GOODIX_BERLIN_FW_VERSION_INFO_ADDR	0x10014
+
+#define GOODIX_BERLIN_IC_INFO_MAX_LEN		SZ_1K
+#define GOODIX_BERLIN_IC_INFO_ADDR		0x10070
+
+struct goodix_berlin_fw_version {
+	u8 rom_pid[6];
+	u8 rom_vid[3];
+	u8 rom_vid_reserved;
+	u8 patch_pid[8];
+	u8 patch_vid[4];
+	u8 patch_vid_reserved;
+	u8 sensor_id;
+	u8 reserved[2];
+	__le16 checksum;
+} __packed;
+
+struct goodix_berlin_ic_info_version {
+	u8 info_customer_id;
+	u8 info_version_id;
+	u8 ic_die_id;
+	u8 ic_version_id;
+	__le32 config_id;
+	u8 config_version;
+	u8 frame_data_customer_id;
+	u8 frame_data_version_id;
+	u8 touch_data_customer_id;
+	u8 touch_data_version_id;
+	u8 reserved[3];
+} __packed;
+
+struct goodix_berlin_ic_info_feature {
+	__le16 freqhop_feature;
+	__le16 calibration_feature;
+	__le16 gesture_feature;
+	__le16 side_touch_feature;
+	__le16 stylus_feature;
+} __packed;
+
+struct goodix_berlin_ic_info_misc {
+	__le32 cmd_addr;
+	__le16 cmd_max_len;
+	__le32 cmd_reply_addr;
+	__le16 cmd_reply_len;
+	__le32 fw_state_addr;
+	__le16 fw_state_len;
+	__le32 fw_buffer_addr;
+	__le16 fw_buffer_max_len;
+	__le32 frame_data_addr;
+	__le16 frame_data_head_len;
+	__le16 fw_attr_len;
+	__le16 fw_log_len;
+	u8 pack_max_num;
+	u8 pack_compress_version;
+	__le16 stylus_struct_len;
+	__le16 mutual_struct_len;
+	__le16 self_struct_len;
+	__le16 noise_struct_len;
+	__le32 touch_data_addr;
+	__le16 touch_data_head_len;
+	__le16 point_struct_len;
+	__le16 reserved1;
+	__le16 reserved2;
+	__le32 mutual_rawdata_addr;
+	__le32 mutual_diffdata_addr;
+	__le32 mutual_refdata_addr;
+	__le32 self_rawdata_addr;
+	__le32 self_diffdata_addr;
+	__le32 self_refdata_addr;
+	__le32 iq_rawdata_addr;
+	__le32 iq_refdata_addr;
+	__le32 im_rawdata_addr;
+	__le16 im_readata_len;
+	__le32 noise_rawdata_addr;
+	__le16 noise_rawdata_len;
+	__le32 stylus_rawdata_addr;
+	__le16 stylus_rawdata_len;
+	__le32 noise_data_addr;
+	__le32 esd_addr;
+} __packed;
+
+struct goodix_berlin_touch_data {
+	u8 id;
+	u8 unused;
+	__le16 x;
+	__le16 y;
+	__le16 w;
+} __packed;
+
+struct goodix_berlin_core {
+	struct device *dev;
+	struct regmap *regmap;
+	struct regulator *avdd;
+	struct regulator *iovdd;
+	struct gpio_desc *reset_gpio;
+	struct touchscreen_properties props;
+	struct goodix_berlin_fw_version fw_version;
+	struct input_dev *input_dev;
+	int irq;
+
+	/* Runtime parameters extracted from IC_INFO buffer  */
+	u32 touch_data_addr;
+};
+
+static bool goodix_berlin_checksum_valid(const u8 *data, int size)
+{
+	u32 cal_checksum = 0;
+	u16 r_checksum;
+	u32 i;
+
+	if (size < GOODIX_BERLIN_COOR_DATA_CHECKSUM_SIZE)
+		return false;
+
+	for (i = 0; i < size - GOODIX_BERLIN_COOR_DATA_CHECKSUM_SIZE; i++)
+		cal_checksum += data[i];
+
+	cal_checksum = FIELD_GET(GOODIX_BERLIN_COOR_DATA_CHECKSUM_MASK,
+				 cal_checksum);
+	r_checksum = get_unaligned_le16(&data[i]);
+
+	return cal_checksum == r_checksum;
+}
+
+static bool goodix_berlin_is_dummy_data(struct goodix_berlin_core *cd,
+					const u8 *data, int size)
+{
+	int i;
+
+	/*
+	 * If the device is missing or doesn't respond the buffer
+	 * could be filled with bus default line state, 0x00 or 0xff,
+	 * so declare success the first time we encounter neither.
+	 */
+	for (i = 0; i < size; i++)
+		if (data[i] > 0 && data[i] < 0xff)
+			return false;
+
+	return true;
+}
+
+static int goodix_berlin_dev_confirm(struct goodix_berlin_core *cd)
+{
+	u8 tx_buf[8], rx_buf[8];
+	int retry = 3;
+	int error;
+
+	memset(tx_buf, GOODIX_BERLIN_DEV_CONFIRM_VAL, sizeof(tx_buf));
+	while (retry--) {
+		error = regmap_raw_write(cd->regmap,
+					 GOODIX_BERLIN_BOOTOPTION_ADDR,
+					 tx_buf, sizeof(tx_buf));
+		if (error)
+			return error;
+
+		error = regmap_raw_read(cd->regmap,
+					GOODIX_BERLIN_BOOTOPTION_ADDR,
+					rx_buf, sizeof(rx_buf));
+		if (error)
+			return error;
+
+		if (!memcmp(tx_buf, rx_buf, sizeof(tx_buf)))
+			return 0;
+
+		usleep_range(5000, 5100);
+	}
+
+	dev_err(cd->dev, "device confirm failed, rx_buf: %*ph\n",
+		(int)sizeof(rx_buf), rx_buf);
+
+	return -EINVAL;
+}
+
+static int goodix_berlin_power_on(struct goodix_berlin_core *cd)
+{
+	int error;
+
+	error = regulator_enable(cd->iovdd);
+	if (error) {
+		dev_err(cd->dev, "Failed to enable iovdd: %d\n", error);
+		return error;
+	}
+
+	/* Vendor waits 3ms for IOVDD to settle */
+	usleep_range(3000, 3100);
+
+	error = regulator_enable(cd->avdd);
+	if (error) {
+		dev_err(cd->dev, "Failed to enable avdd: %d\n", error);
+		goto err_iovdd_disable;
+	}
+
+	/* Vendor waits 15ms for IOVDD to settle */
+	usleep_range(15000, 15100);
+
+	gpiod_set_value_cansleep(cd->reset_gpio, 0);
+
+	/* Vendor waits 4ms for Firmware to initialize */
+	usleep_range(4000, 4100);
+
+	error = goodix_berlin_dev_confirm(cd);
+	if (error)
+		goto err_dev_reset;
+
+	/* Vendor waits 100ms for Firmware to fully boot */
+	msleep(GOODIX_BERLIN_NORMAL_RESET_DELAY_MS);
+
+	return 0;
+
+err_dev_reset:
+	gpiod_set_value_cansleep(cd->reset_gpio, 1);
+	regulator_disable(cd->avdd);
+err_iovdd_disable:
+	regulator_disable(cd->iovdd);
+	return error;
+}
+
+static void goodix_berlin_power_off(struct goodix_berlin_core *cd)
+{
+	gpiod_set_value_cansleep(cd->reset_gpio, 1);
+	regulator_disable(cd->avdd);
+	regulator_disable(cd->iovdd);
+}
+
+static int goodix_berlin_read_version(struct goodix_berlin_core *cd)
+{
+	u8 buf[sizeof(struct goodix_berlin_fw_version)];
+	int error;
+
+	error = regmap_raw_read(cd->regmap, GOODIX_BERLIN_FW_VERSION_INFO_ADDR,
+				buf, sizeof(buf));
+	if (error) {
+		dev_err(cd->dev, "error reading fw version, %d\n", error);
+		return error;
+	}
+
+	if (!goodix_berlin_checksum_valid(buf, sizeof(buf))) {
+		dev_err(cd->dev, "invalid fw version: checksum error\n");
+		return -EINVAL;
+	}
+
+	memcpy(&cd->fw_version, buf, sizeof(cd->fw_version));
+
+	return 0;
+}
+
+/* Only extract necessary data for runtime */
+static int goodix_berlin_convert_ic_info(struct goodix_berlin_core *cd,
+					 const u8 *data, u16 length)
+{
+	struct goodix_berlin_ic_info_misc misc;
+	unsigned int offset = 0;
+	u8 param_num;
+
+	offset += sizeof(__le16); /* length */
+	offset += sizeof(struct goodix_berlin_ic_info_version);
+	offset += sizeof(struct goodix_berlin_ic_info_feature);
+
+	/* IC_INFO Parameters, variable width structure */
+	offset += 4 * sizeof(u8); /* drv_num, sen_num, button_num, force_num */
+
+	if (offset >= length)
+		goto invalid_offset;
+
+	param_num = data[offset++]; /* active_scan_rate_num */
+
+	offset += param_num * sizeof(__le16);
+
+	if (offset >= length)
+		goto invalid_offset;
+
+	param_num = data[offset++]; /* mutual_freq_num*/
+
+	offset += param_num * sizeof(__le16);
+
+	if (offset >= length)
+		goto invalid_offset;
+
+	param_num = data[offset++]; /* self_tx_freq_num */
+
+	offset += param_num * sizeof(__le16);
+
+	if (offset >= length)
+		goto invalid_offset;
+
+	param_num = data[offset++]; /* self_rx_freq_num */
+
+	offset += param_num * sizeof(__le16);
+
+	if (offset >= length)
+		goto invalid_offset;
+
+	param_num = data[offset++]; /* stylus_freq_num */
+
+	offset += param_num * sizeof(__le16);
+
+	if (offset + sizeof(misc) > length)
+		goto invalid_offset;
+
+	/* goodix_berlin_ic_info_misc */
+	memcpy(&misc, &data[offset], sizeof(misc));
+
+	cd->touch_data_addr = le32_to_cpu(misc.touch_data_addr);
+
+	return 0;
+
+invalid_offset:
+	dev_err(cd->dev, "ic_info length is invalid (offset %d length %d)\n",
+		offset, length);
+	return -EINVAL;
+}
+
+static int goodix_berlin_get_ic_info(struct goodix_berlin_core *cd)
+{
+	u8 *afe_data __free(kfree) = NULL;
+	__le16 length_raw;
+	u16 length;
+	int error;
+
+	afe_data = kzalloc(GOODIX_BERLIN_IC_INFO_MAX_LEN, GFP_KERNEL);
+	if (!afe_data)
+		return -ENOMEM;
+
+	error = regmap_raw_read(cd->regmap, GOODIX_BERLIN_IC_INFO_ADDR,
+				&length_raw, sizeof(length_raw));
+	if (error) {
+		dev_err(cd->dev, "failed get ic info length, %d\n", error);
+		return error;
+	}
+
+	length = le16_to_cpu(length_raw);
+	if (length >= GOODIX_BERLIN_IC_INFO_MAX_LEN) {
+		dev_err(cd->dev, "invalid ic info length %d\n", length);
+		return -EINVAL;
+	}
+
+	error = regmap_raw_read(cd->regmap, GOODIX_BERLIN_IC_INFO_ADDR,
+				afe_data, length);
+	if (error) {
+		dev_err(cd->dev, "failed get ic info data, %d\n", error);
+		return error;
+	}
+
+	/* check whether the data is valid (ex. bus default values) */
+	if (goodix_berlin_is_dummy_data(cd, afe_data, length)) {
+		dev_err(cd->dev, "fw info data invalid\n");
+		return -EINVAL;
+	}
+
+	if (!goodix_berlin_checksum_valid(afe_data, length)) {
+		dev_err(cd->dev, "fw info checksum error\n");
+		return -EINVAL;
+	}
+
+	error = goodix_berlin_convert_ic_info(cd, afe_data, length);
+	if (error)
+		return error;
+
+	/* check some key info */
+	if (!cd->touch_data_addr) {
+		dev_err(cd->dev, "touch_data_addr is null\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void goodix_berlin_parse_finger(struct goodix_berlin_core *cd,
+				       const void *buf, int touch_num)
+{
+	const struct goodix_berlin_touch_data *touch_data = buf;
+	int i;
+
+	/* Report finger touches */
+	for (i = 0; i < touch_num; i++) {
+		unsigned int id = FIELD_GET(GOODIX_BERLIN_TOUCH_ID_MASK,
+					    touch_data[i].id);
+
+		if (id >= GOODIX_BERLIN_MAX_TOUCH) {
+			dev_warn_ratelimited(cd->dev,
+					     "invalid finger id %d\n", id);
+			continue;
+		}
+
+		input_mt_slot(cd->input_dev, id);
+		input_mt_report_slot_state(cd->input_dev, MT_TOOL_FINGER, true);
+
+		touchscreen_report_pos(cd->input_dev, &cd->props,
+				       __le16_to_cpu(touch_data[i].x),
+				       __le16_to_cpu(touch_data[i].y),
+				       true);
+		input_report_abs(cd->input_dev, ABS_MT_TOUCH_MAJOR,
+				 __le16_to_cpu(touch_data[i].w));
+	}
+
+	input_mt_sync_frame(cd->input_dev);
+	input_sync(cd->input_dev);
+}
+
+static void goodix_berlin_touch_handler(struct goodix_berlin_core *cd,
+					const void *pre_buf, u32 pre_buf_len)
+{
+	u8 buffer[GOODIX_BERLIN_IRQ_READ_LEN(GOODIX_BERLIN_MAX_TOUCH)];
+	u8 point_type, touch_num;
+	int error;
+
+	/* copy pre-data to buffer */
+	memcpy(buffer, pre_buf, pre_buf_len);
+
+	touch_num = FIELD_GET(GOODIX_BERLIN_TOUCH_COUNT_MASK,
+			      buffer[GOODIX_BERLIN_REQUEST_TYPE_OFFSET]);
+
+	if (touch_num > GOODIX_BERLIN_MAX_TOUCH) {
+		dev_warn(cd->dev, "invalid touch num %d\n", touch_num);
+		return;
+	}
+
+	if (touch_num) {
+		/* read more data if more than 2 touch events */
+		if (unlikely(touch_num > 2)) {
+			error = regmap_raw_read(cd->regmap,
+						cd->touch_data_addr + pre_buf_len,
+						&buffer[pre_buf_len],
+						(touch_num - 2) * GOODIX_BERLIN_BYTES_PER_POINT);
+			if (error) {
+				dev_err_ratelimited(cd->dev, "failed to get touch data, %d\n",
+						    error);
+				return;
+			}
+		}
+
+		point_type = FIELD_GET(GOODIX_BERLIN_POINT_TYPE_MASK,
+				       buffer[GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN]);
+
+		if (point_type == GOODIX_BERLIN_POINT_TYPE_STYLUS ||
+		    point_type == GOODIX_BERLIN_POINT_TYPE_STYLUS_HOVER) {
+			dev_warn_once(cd->dev, "Stylus event type not handled\n");
+			return;
+		}
+
+		if (!goodix_berlin_checksum_valid(&buffer[GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN],
+						  touch_num * GOODIX_BERLIN_BYTES_PER_POINT + 2)) {
+			dev_err(cd->dev, "touch data checksum error: %*ph\n",
+				touch_num * GOODIX_BERLIN_BYTES_PER_POINT + 2,
+				&buffer[GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN]);
+			return;
+		}
+	}
+
+	goodix_berlin_parse_finger(cd, &buffer[GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN],
+				   touch_num);
+}
+
+static int goodix_berlin_request_handle_reset(struct goodix_berlin_core *cd)
+{
+	gpiod_set_value_cansleep(cd->reset_gpio, 1);
+	usleep_range(2000, 2100);
+	gpiod_set_value_cansleep(cd->reset_gpio, 0);
+
+	msleep(GOODIX_BERLIN_NORMAL_RESET_DELAY_MS);
+
+	return 0;
+}
+
+static irqreturn_t goodix_berlin_irq(int irq, void *data)
+{
+	struct goodix_berlin_core *cd = data;
+	u8 buf[GOODIX_BERLIN_IRQ_READ_LEN(2)];
+	u8 event_status;
+	int error;
+
+	/*
+	 * First, read buffer with space for 2 touch events:
+	 * - GOODIX_BERLIN_IRQ_EVENT_HEAD = 8 bytes
+	 * - GOODIX_BERLIN_BYTES_PER_POINT * 2 +
+	 *   GOODIX_BERLIN_COOR_DATA_CHECKSUM = 18 bytes
+	 * For a total of 26 bytes.
+	 *
+	 * If only a single finger is reported, we will read 8 bytes more than needed:
+	 * - bytes 0-7:   GOODIX_BERLIN_IRQ_EVENT_HEAD
+	 * - bytes 8-15:  Finger 0 Data
+	 * - bytes 16-17: GOODIX_BERLIN_COOR_DATA_CHECKSUM
+	 * - bytes 18-25: Unused 8 bytes
+	 *
+	 * If 2 fingers are reported, we would have read the exact needed amount of
+	 * data and checkout would be at the end of the buffer:
+	 * - bytes 0-7:	  GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN
+	 * - bytes 8-15:  Finger 0 Bytes 0-7
+	 * - bytes 16-23: Finger 1 Bytes 0-7
+	 * - bytes 24-25: GOODIX_BERLIN_COOR_DATA_CHECKSUM
+	 *
+	 * If more than 2 fingers were reported, the "Checksum" bytes would in fact
+	 * contain part of the next finger data, and then we would complete the buffer
+	 * with the missing bytes, but by keeping the GOODIX_BERLIN_IRQ_READ_LEN(2)
+	 * size as base, it will still contain space for the final 2 bytes checksum:
+	 * - bytes 0-7:	  GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN]
+	 * - bytes 8-15:  Finger 0 Bytes 0-7
+	 * - bytes 16-23: Finger 1 Bytes 0-7
+	 * - bytes 24-25: Finger 2 Bytes 0-1
+	 * for example if 3 fingers are reported, (3 - 2) * 8 = 8 bytes would be read:
+	 * - bytes 26-31: Finger 2 Bytes 2-7
+	 * - bytes 32-33: GOODIX_BERLIN_COOR_DATA_CHECKSUM
+	 */
+	error = regmap_raw_read(cd->regmap, cd->touch_data_addr, buf,
+				GOODIX_BERLIN_IRQ_READ_LEN(2));
+	if (error) {
+		dev_warn_ratelimited(cd->dev,
+				     "failed get event head data: %d\n", error);
+		return IRQ_HANDLED;
+	}
+
+	if (buf[GOODIX_BERLIN_STATUS_OFFSET] == 0)
+		return IRQ_HANDLED;
+
+	if (!goodix_berlin_checksum_valid(buf, GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN)) {
+		dev_warn_ratelimited(cd->dev,
+				     "touch head checksum error: %*ph\n",
+				     GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN, buf);
+		return IRQ_HANDLED;
+	}
+
+	event_status = buf[GOODIX_BERLIN_STATUS_OFFSET];
+
+	if (event_status & GOODIX_BERLIN_TOUCH_EVENT)
+		goodix_berlin_touch_handler(cd, buf,
+					    GOODIX_BERLIN_IRQ_READ_LEN(2));
+
+	if (event_status & GOODIX_BERLIN_REQUEST_EVENT) {
+		switch (buf[GOODIX_BERLIN_REQUEST_TYPE_OFFSET]) {
+		case GOODIX_BERLIN_REQUEST_CODE_RESET:
+			if (cd->reset_gpio)
+				goodix_berlin_request_handle_reset(cd);
+			break;
+
+		default:
+			dev_warn(cd->dev, "unsupported request code 0x%x\n",
+				 buf[GOODIX_BERLIN_REQUEST_TYPE_OFFSET]);
+		}
+	}
+
+	/* Clear up status field */
+	regmap_write(cd->regmap, cd->touch_data_addr, 0);
+
+	return IRQ_HANDLED;
+}
+
+static int goodix_berlin_input_dev_config(struct goodix_berlin_core *cd,
+					  const struct input_id *id)
+{
+	struct input_dev *input_dev;
+	int error;
+
+	input_dev = devm_input_allocate_device(cd->dev);
+	if (!input_dev)
+		return -ENOMEM;
+
+	cd->input_dev = input_dev;
+	input_set_drvdata(input_dev, cd);
+
+	input_dev->name = "Goodix Berlin Capacitive TouchScreen";
+	input_dev->phys = "input/ts";
+
+	input_dev->id = *id;
+
+	input_set_abs_params(cd->input_dev, ABS_MT_POSITION_X,
+			     0, SZ_64K - 1, 0, 0);
+	input_set_abs_params(cd->input_dev, ABS_MT_POSITION_Y,
+			     0, SZ_64K - 1, 0, 0);
+	input_set_abs_params(cd->input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
+
+	touchscreen_parse_properties(cd->input_dev, true, &cd->props);
+
+	error = input_mt_init_slots(cd->input_dev, GOODIX_BERLIN_MAX_TOUCH,
+				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+	if (error)
+		return error;
+
+	error = input_register_device(cd->input_dev);
+	if (error)
+		return error;
+
+	return 0;
+}
+
+static int goodix_berlin_suspend(struct device *dev)
+{
+	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
+
+	disable_irq(cd->irq);
+	goodix_berlin_power_off(cd);
+
+	return 0;
+}
+
+static int goodix_berlin_resume(struct device *dev)
+{
+	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
+	int error;
+
+	error = goodix_berlin_power_on(cd);
+	if (error)
+		return error;
+
+	enable_irq(cd->irq);
+
+	return 0;
+}
+
+EXPORT_GPL_SIMPLE_DEV_PM_OPS(goodix_berlin_pm_ops,
+			     goodix_berlin_suspend, goodix_berlin_resume);
+
+static void goodix_berlin_power_off_act(void *data)
+{
+	struct goodix_berlin_core *cd = data;
+
+	goodix_berlin_power_off(cd);
+}
+
+int goodix_berlin_probe(struct device *dev, int irq, const struct input_id *id,
+			struct regmap *regmap)
+{
+	struct goodix_berlin_core *cd;
+	int error;
+
+	if (irq <= 0) {
+		dev_err(dev, "Missing interrupt number\n");
+		return -EINVAL;
+	}
+
+	cd = devm_kzalloc(dev, sizeof(*cd), GFP_KERNEL);
+	if (!cd)
+		return -ENOMEM;
+
+	cd->dev = dev;
+	cd->regmap = regmap;
+	cd->irq = irq;
+
+	cd->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(cd->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(cd->reset_gpio),
+				     "Failed to request reset gpio\n");
+
+	cd->avdd = devm_regulator_get(dev, "avdd");
+	if (IS_ERR(cd->avdd))
+		return dev_err_probe(dev, PTR_ERR(cd->avdd),
+				     "Failed to request avdd regulator\n");
+
+	cd->iovdd = devm_regulator_get(dev, "iovdd");
+	if (IS_ERR(cd->iovdd))
+		return dev_err_probe(dev, PTR_ERR(cd->iovdd),
+				     "Failed to request iovdd regulator\n");
+
+	error = goodix_berlin_power_on(cd);
+	if (error) {
+		dev_err(dev, "failed power on");
+		return error;
+	}
+
+	error = devm_add_action_or_reset(dev, goodix_berlin_power_off_act, cd);
+	if (error)
+		return error;
+
+	error = goodix_berlin_read_version(cd);
+	if (error) {
+		dev_err(dev, "failed to get version info");
+		return error;
+	}
+
+	error = goodix_berlin_get_ic_info(cd);
+	if (error) {
+		dev_err(dev, "invalid ic info, abort");
+		return error;
+	}
+
+	error = goodix_berlin_input_dev_config(cd, id);
+	if (error) {
+		dev_err(dev, "failed set input device");
+		return error;
+	}
+
+	error = devm_request_threaded_irq(dev, cd->irq, NULL, goodix_berlin_irq,
+					  IRQF_ONESHOT, "goodix-berlin", cd);
+	if (error) {
+		dev_err(dev, "request threaded irq failed: %d\n", error);
+		return error;
+	}
+
+	dev_set_drvdata(dev, cd);
+
+	dev_dbg(dev, "Goodix Berlin %s Touchscreen Controller",
+		cd->fw_version.patch_pid);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(goodix_berlin_probe);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Goodix Berlin Core Touchscreen driver");
+MODULE_AUTHOR("Neil Armstrong <neil.armstrong@linaro.org>");

-- 
2.34.1

[PATCH v14 3/4] Input: goodix-berlin - add I2C support for Goodix Berlin Touchscreen IC

[Neil Armstrong]

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 | 75 +++++++++++++++++++++++++++
 3 files changed, 90 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..6ed9aa8088cb
--- /dev/null
+++ b/drivers/input/touchscreen/goodix_berlin_i2c.c
@@ -0,0 +1,75 @@
+// 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 <linux/input.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

[PATCH v14 4/4] Input: goodix-berlin - add SPI support for Goodix Berlin Touchscreen IC

[Neil Armstrong]

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

The driver doesn't use the regmap_spi code since the SPI messages
needs to be prefixed, thus this custom regmap code.

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_spi.c | 178 ++++++++++++++++++++++++++
 3 files changed, 193 insertions(+)

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index cc7b88118158..c821fe3ee794 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -433,6 +433,20 @@ config TOUCHSCREEN_GOODIX_BERLIN_I2C
 	  To compile this driver as a module, choose M here: the
 	  module will be called goodix_berlin_i2c.
 
+config TOUCHSCREEN_GOODIX_BERLIN_SPI
+	tristate "Goodix Berlin SPI touchscreen"
+	depends on SPI_MASTER
+	select REGMAP
+	select TOUCHSCREEN_GOODIX_BERLIN_CORE
+	help
+	  Say Y here if you have a Goodix Berlin IC connected to
+	  your system via SPI.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called goodix_berlin_spi.
+
 config TOUCHSCREEN_HIDEEP
 	tristate "HiDeep Touch IC"
 	depends on I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 7ef677cf7a10..a81cb5aa21a5 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -49,6 +49,7 @@ 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-$(CONFIG_TOUCHSCREEN_GOODIX_BERLIN_SPI)	+= goodix_berlin_spi.o
 obj-$(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_spi.c b/drivers/input/touchscreen/goodix_berlin_spi.c
new file mode 100644
index 000000000000..4cc557da048a
--- /dev/null
+++ b/drivers/input/touchscreen/goodix_berlin_spi.c
@@ -0,0 +1,178 @@
+// 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 <asm/unaligned.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/input.h>
+
+#include "goodix_berlin.h"
+
+#define GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN	1
+#define GOODIX_BERLIN_REGISTER_WIDTH		4
+#define GOODIX_BERLIN_SPI_READ_DUMMY_LEN	3
+#define GOODIX_BERLIN_SPI_READ_PREFIX_LEN	(GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + \
+						 GOODIX_BERLIN_REGISTER_WIDTH + \
+						 GOODIX_BERLIN_SPI_READ_DUMMY_LEN)
+#define GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN	(GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + \
+						 GOODIX_BERLIN_REGISTER_WIDTH)
+
+#define GOODIX_BERLIN_SPI_WRITE_FLAG		0xF0
+#define GOODIX_BERLIN_SPI_READ_FLAG		0xF1
+
+static int goodix_berlin_spi_read(void *context, const void *reg_buf,
+				  size_t reg_size, void *val_buf,
+				  size_t val_size)
+{
+	struct spi_device *spi = context;
+	struct spi_transfer xfers;
+	struct spi_message spi_msg;
+	const u32 *reg = reg_buf; /* reg is stored as native u32 at start of buffer */
+	u8 *buf;
+	int error;
+
+	if (reg_size != GOODIX_BERLIN_REGISTER_WIDTH)
+		return -EINVAL;
+
+	buf = kzalloc(GOODIX_BERLIN_SPI_READ_PREFIX_LEN + val_size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	spi_message_init(&spi_msg);
+	memset(&xfers, 0, sizeof(xfers));
+
+	/* buffer format: 0xF1 + addr(4bytes) + dummy(3bytes) + data */
+	buf[0] = GOODIX_BERLIN_SPI_READ_FLAG;
+	put_unaligned_be32(*reg, buf + GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN);
+	memset(buf + GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + GOODIX_BERLIN_REGISTER_WIDTH,
+	       0xff, GOODIX_BERLIN_SPI_READ_DUMMY_LEN);
+
+	xfers.tx_buf = buf;
+	xfers.rx_buf = buf;
+	xfers.len = GOODIX_BERLIN_SPI_READ_PREFIX_LEN + val_size;
+	xfers.cs_change = 0;
+	spi_message_add_tail(&xfers, &spi_msg);
+
+	error = spi_sync(spi, &spi_msg);
+	if (error < 0)
+		dev_err(&spi->dev, "spi transfer error, %d", error);
+	else
+		memcpy(val_buf, buf + GOODIX_BERLIN_SPI_READ_PREFIX_LEN, val_size);
+
+	kfree(buf);
+	return error;
+}
+
+static int goodix_berlin_spi_write(void *context, const void *data,
+				   size_t count)
+{
+	unsigned int len = count - GOODIX_BERLIN_REGISTER_WIDTH;
+	struct spi_device *spi = context;
+	struct spi_transfer xfers;
+	struct spi_message spi_msg;
+	const u32 *reg = data; /* reg is stored as native u32 at start of buffer */
+	u8 *buf;
+	int error;
+
+	buf = kzalloc(GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN + len, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	spi_message_init(&spi_msg);
+	memset(&xfers, 0, sizeof(xfers));
+
+	buf[0] = GOODIX_BERLIN_SPI_WRITE_FLAG;
+	put_unaligned_be32(*reg, buf + GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN);
+	memcpy(buf + GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN,
+	       data + GOODIX_BERLIN_REGISTER_WIDTH, len);
+
+	xfers.tx_buf = buf;
+	xfers.len = GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN + len;
+	xfers.cs_change = 0;
+	spi_message_add_tail(&xfers, &spi_msg);
+
+	error = spi_sync(spi, &spi_msg);
+	if (error < 0)
+		dev_err(&spi->dev, "spi transfer error, %d", error);
+
+	kfree(buf);
+	return error;
+}
+
+static const struct regmap_config goodix_berlin_spi_regmap_conf = {
+	.reg_bits = 32,
+	.val_bits = 8,
+	.read = goodix_berlin_spi_read,
+	.write = goodix_berlin_spi_write,
+};
+
+/* vendor & product left unassigned here, should probably be updated from fw info */
+static const struct input_id goodix_berlin_spi_input_id = {
+	.bustype = BUS_SPI,
+};
+
+static int goodix_berlin_spi_probe(struct spi_device *spi)
+{
+	struct regmap_config regmap_config;
+	struct regmap *regmap;
+	size_t max_size;
+	int error = 0;
+
+	spi->mode = SPI_MODE_0;
+	spi->bits_per_word = 8;
+	error = spi_setup(spi);
+	if (error)
+		return error;
+
+	max_size = spi_max_transfer_size(spi);
+
+	regmap_config = goodix_berlin_spi_regmap_conf;
+	regmap_config.max_raw_read = max_size - GOODIX_BERLIN_SPI_READ_PREFIX_LEN;
+	regmap_config.max_raw_write = max_size - GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN;
+
+	regmap = devm_regmap_init(&spi->dev, NULL, spi, &regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	error = goodix_berlin_probe(&spi->dev, spi->irq,
+				    &goodix_berlin_spi_input_id, regmap);
+	if (error)
+		return error;
+
+	return 0;
+}
+
+static const struct spi_device_id goodix_berlin_spi_ids[] = {
+	{ "gt9916" },
+	{ },
+};
+MODULE_DEVICE_TABLE(spi, goodix_berlin_spi_ids);
+
+static const struct of_device_id goodix_berlin_spi_of_match[] = {
+	{ .compatible = "goodix,gt9916", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, goodix_berlin_spi_of_match);
+
+static struct spi_driver goodix_berlin_spi_driver = {
+	.driver = {
+		.name = "goodix-berlin-spi",
+		.of_match_table = goodix_berlin_spi_of_match,
+		.pm = pm_sleep_ptr(&goodix_berlin_pm_ops),
+	},
+	.probe = goodix_berlin_spi_probe,
+	.id_table = goodix_berlin_spi_ids,
+};
+module_spi_driver(goodix_berlin_spi_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Goodix Berlin SPI Touchscreen driver");
+MODULE_AUTHOR("Neil Armstrong <neil.armstrong@linaro.org>");

-- 
2.34.1

Re: [PATCH v14 2/4] Input: add core support for Goodix Berlin Touchscreen IC

[Dmitry Torokhov]

Hi Neil,

On Thu, Dec 21, 2023 at 04:21:20PM +0100, Neil Armstrong wrote:
> Add initial support for the new Goodix "Berlin" touchscreen ICs.

Thank you very much for explaining how reading of additional contacts
and checksum works, it makes sense now.

I was a bit unhappy about number of times we copy/move the data over;
could you please try the patch below to see if the device still works
with it?

I also shortened some #defines and defines some additional structures.
Also as far as I can see not everything needs to be packed as the data
is naturally aligned on the word boundaries.

Thanks!

-- 
Dmitry


diff --git a/drivers/input/touchscreen/goodix_berlin_core.c b/drivers/input/touchscreen/goodix_berlin_core.c
index 6aca57e6b5d6..d1f1c0474116 100644
--- a/drivers/input/touchscreen/goodix_berlin_core.c
+++ b/drivers/input/touchscreen/goodix_berlin_core.c
@@ -39,19 +39,6 @@
 
 #define GOODIX_BERLIN_NORMAL_RESET_DELAY_MS	100
 
-#define GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN	8
-#define GOODIX_BERLIN_STATUS_OFFSET		0
-#define GOODIX_BERLIN_REQUEST_TYPE_OFFSET	2
-
-#define GOODIX_BERLIN_BYTES_PER_POINT		8
-#define GOODIX_BERLIN_COOR_DATA_CHECKSUM_SIZE	2
-#define GOODIX_BERLIN_COOR_DATA_CHECKSUM_MASK	GENMASK(15, 0)
-
-/* Read n finger events */
-#define GOODIX_BERLIN_IRQ_READ_LEN(n)		(GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN + \
-						 (GOODIX_BERLIN_BYTES_PER_POINT * (n)) + \
-						 GOODIX_BERLIN_COOR_DATA_CHECKSUM_SIZE)
-
 #define GOODIX_BERLIN_TOUCH_EVENT		BIT(7)
 #define GOODIX_BERLIN_REQUEST_EVENT		BIT(6)
 #define GOODIX_BERLIN_TOUCH_COUNT_MASK		GENMASK(3, 0)
@@ -71,6 +58,8 @@
 #define GOODIX_BERLIN_IC_INFO_MAX_LEN		SZ_1K
 #define GOODIX_BERLIN_IC_INFO_ADDR		0x10070
 
+#define GOODIX_BERLIN_CHECKSUM_SIZE		sizeof(u16)
+
 struct goodix_berlin_fw_version {
 	u8 rom_pid[6];
 	u8 rom_vid[3];
@@ -81,7 +70,7 @@ struct goodix_berlin_fw_version {
 	u8 sensor_id;
 	u8 reserved[2];
 	__le16 checksum;
-} __packed;
+};
 
 struct goodix_berlin_ic_info_version {
 	u8 info_customer_id;
@@ -147,13 +136,30 @@ struct goodix_berlin_ic_info_misc {
 	__le32 esd_addr;
 } __packed;
 
-struct goodix_berlin_touch_data {
-	u8 id;
-	u8 unused;
+struct goodix_berlin_touch {
+	u8 status;
+	u8 reserved;
 	__le16 x;
 	__le16 y;
 	__le16 w;
-} __packed;
+};
+#define GOODIX_BERLIN_TOUCH_SIZE	sizeof(struct goodix_berlin_touch)
+
+struct goodix_berlin_header {
+	u8 status;
+	u8 reserved1;
+	u8 request_type;
+	u8 reserved2[3];
+	__le16 checksum;
+};
+#define GOODIX_BERLIN_HEADER_SIZE	sizeof(struct goodix_berlin_header)
+
+struct goodix_berlin_event {
+	struct goodix_berlin_header hdr;
+	/* The data below is u16/__le16 aligned */
+	u8 data[GOODIX_BERLIN_TOUCH_SIZE * GOODIX_BERLIN_MAX_TOUCH +
+		GOODIX_BERLIN_CHECKSUM_SIZE];
+};
 
 struct goodix_berlin_core {
 	struct device *dev;
@@ -168,25 +174,25 @@ struct goodix_berlin_core {
 
 	/* Runtime parameters extracted from IC_INFO buffer  */
 	u32 touch_data_addr;
+
+	struct goodix_berlin_event event;
 };
 
 static bool goodix_berlin_checksum_valid(const u8 *data, int size)
 {
 	u32 cal_checksum = 0;
 	u16 r_checksum;
-	u32 i;
+	int i;
 
-	if (size < GOODIX_BERLIN_COOR_DATA_CHECKSUM_SIZE)
+	if (size < GOODIX_BERLIN_CHECKSUM_SIZE)
 		return false;
 
-	for (i = 0; i < size - GOODIX_BERLIN_COOR_DATA_CHECKSUM_SIZE; i++)
+	for (i = 0; i < size - GOODIX_BERLIN_CHECKSUM_SIZE; i++)
 		cal_checksum += data[i];
 
-	cal_checksum = FIELD_GET(GOODIX_BERLIN_COOR_DATA_CHECKSUM_MASK,
-				 cal_checksum);
 	r_checksum = get_unaligned_le16(&data[i]);
 
-	return cal_checksum == r_checksum;
+	return (u16)cal_checksum == r_checksum;
 }
 
 static bool goodix_berlin_is_dummy_data(struct goodix_berlin_core *cd,
@@ -291,33 +297,30 @@ static void goodix_berlin_power_off(struct goodix_berlin_core *cd)
 
 static int goodix_berlin_read_version(struct goodix_berlin_core *cd)
 {
-	u8 buf[sizeof(struct goodix_berlin_fw_version)];
 	int error;
 
 	error = regmap_raw_read(cd->regmap, GOODIX_BERLIN_FW_VERSION_INFO_ADDR,
-				buf, sizeof(buf));
+				&cd->fw_version, sizeof(cd->fw_version));
 	if (error) {
 		dev_err(cd->dev, "error reading fw version, %d\n", error);
 		return error;
 	}
 
-	if (!goodix_berlin_checksum_valid(buf, sizeof(buf))) {
+	if (!goodix_berlin_checksum_valid((u8 *)&cd->fw_version,
+					  sizeof(cd->fw_version))) {
 		dev_err(cd->dev, "invalid fw version: checksum error\n");
 		return -EINVAL;
 	}
 
-	memcpy(&cd->fw_version, buf, sizeof(cd->fw_version));
-
 	return 0;
 }
 
 /* Only extract necessary data for runtime */
-static int goodix_berlin_convert_ic_info(struct goodix_berlin_core *cd,
-					 const u8 *data, u16 length)
+static int goodix_berlin_parse_ic_info(struct goodix_berlin_core *cd,
+				       const u8 *data, u16 length)
 {
-	struct goodix_berlin_ic_info_misc misc;
+	struct goodix_berlin_ic_info_misc *misc;
 	unsigned int offset = 0;
-	u8 param_num;
 
 	offset += sizeof(__le16); /* length */
 	offset += sizeof(struct goodix_berlin_ic_info_version);
@@ -325,49 +328,25 @@ static int goodix_berlin_convert_ic_info(struct goodix_berlin_core *cd,
 
 	/* IC_INFO Parameters, variable width structure */
 	offset += 4 * sizeof(u8); /* drv_num, sen_num, button_num, force_num */
-
-	if (offset >= length)
-		goto invalid_offset;
-
-	param_num = data[offset++]; /* active_scan_rate_num */
-
-	offset += param_num * sizeof(__le16);
-
-	if (offset >= length)
-		goto invalid_offset;
-
-	param_num = data[offset++]; /* mutual_freq_num*/
-
-	offset += param_num * sizeof(__le16);
-
-	if (offset >= length)
-		goto invalid_offset;
-
-	param_num = data[offset++]; /* self_tx_freq_num */
-
-	offset += param_num * sizeof(__le16);
-
-	if (offset >= length)
-		goto invalid_offset;
-
-	param_num = data[offset++]; /* self_rx_freq_num */
-
-	offset += param_num * sizeof(__le16);
-
 	if (offset >= length)
 		goto invalid_offset;
 
-	param_num = data[offset++]; /* stylus_freq_num */
-
-	offset += param_num * sizeof(__le16);
-
-	if (offset + sizeof(misc) > length)
-		goto invalid_offset;
-
-	/* goodix_berlin_ic_info_misc */
-	memcpy(&misc, &data[offset], sizeof(misc));
-
-	cd->touch_data_addr = le32_to_cpu(misc.touch_data_addr);
+#define ADVANCE_LE16_PARAMS()				\
+	do {						\
+		u8 param_num = data[offset++];		\
+		offset += param_num * sizeof(__le16);	\
+		if (offset >= length)			\
+			goto invalid_offset;		\
+	} while (0)
+	ADVANCE_LE16_PARAMS(); /* active_scan_rate_num */
+	ADVANCE_LE16_PARAMS(); /* mutual_freq_num*/
+	ADVANCE_LE16_PARAMS(); /* self_tx_freq_num */
+	ADVANCE_LE16_PARAMS(); /* self_rx_freq_num */
+	ADVANCE_LE16_PARAMS(); /* stylus_freq_num */
+#undef ADVANCE_LE16_PARAMS
+
+	misc = (struct goodix_berlin_ic_info_misc *)&data[offset];
+	cd->touch_data_addr = le32_to_cpu(misc->touch_data_addr);
 
 	return 0;
 
@@ -419,7 +398,7 @@ static int goodix_berlin_get_ic_info(struct goodix_berlin_core *cd)
 		return -EINVAL;
 	}
 
-	error = goodix_berlin_convert_ic_info(cd, afe_data, length);
+	error = goodix_berlin_parse_ic_info(cd, afe_data, length);
 	if (error)
 		return error;
 
@@ -432,20 +411,47 @@ static int goodix_berlin_get_ic_info(struct goodix_berlin_core *cd)
 	return 0;
 }
 
-static void goodix_berlin_parse_finger(struct goodix_berlin_core *cd,
-				       const void *buf, int touch_num)
+static int goodix_berlin_get_remaining_contacts(struct goodix_berlin_core *cd,
+						int n)
+{
+	size_t offset = 2 * GOODIX_BERLIN_TOUCH_SIZE +
+				GOODIX_BERLIN_CHECKSUM_SIZE;
+	u32 addr = cd->touch_data_addr + GOODIX_BERLIN_HEADER_SIZE + offset;
+	int error;
+
+	error = regmap_raw_read(cd->regmap, addr,
+				&cd->event.data[offset],
+				(n - 2) * GOODIX_BERLIN_TOUCH_SIZE);
+	if (error) {
+		dev_err_ratelimited(cd->dev, "failed to get touch data, %d\n",
+				    error);
+		return error;
+	}
+
+	return 0;
+}
+
+static void goodix_berlin_report_state(struct goodix_berlin_core *cd, int n)
 {
-	const struct goodix_berlin_touch_data *touch_data = buf;
+	struct goodix_berlin_touch *touch_data =
+			(struct goodix_berlin_touch *)cd->event.data;
+	struct goodix_berlin_touch *t;
 	int i;
+	u8 type, id;
+
+	for (i = 0; i < n; i++) {
+		t = &touch_data[i];
 
-	/* Report finger touches */
-	for (i = 0; i < touch_num; i++) {
-		unsigned int id = FIELD_GET(GOODIX_BERLIN_TOUCH_ID_MASK,
-					    touch_data[i].id);
+		type = FIELD_GET(GOODIX_BERLIN_POINT_TYPE_MASK, t->status);
+		if (type == GOODIX_BERLIN_POINT_TYPE_STYLUS ||
+		    type == GOODIX_BERLIN_POINT_TYPE_STYLUS_HOVER) {
+			dev_warn_once(cd->dev, "Stylus event type not handled\n");
+			continue;
+		}
 
+		id = FIELD_GET(GOODIX_BERLIN_TOUCH_ID_MASK, t->status);
 		if (id >= GOODIX_BERLIN_MAX_TOUCH) {
-			dev_warn_ratelimited(cd->dev,
-					     "invalid finger id %d\n", id);
+			dev_warn_ratelimited(cd->dev, "invalid finger id %d\n", id);
 			continue;
 		}
 
@@ -453,69 +459,46 @@ static void goodix_berlin_parse_finger(struct goodix_berlin_core *cd,
 		input_mt_report_slot_state(cd->input_dev, MT_TOOL_FINGER, true);
 
 		touchscreen_report_pos(cd->input_dev, &cd->props,
-				       __le16_to_cpu(touch_data[i].x),
-				       __le16_to_cpu(touch_data[i].y),
+				       __le16_to_cpu(t->x), __le16_to_cpu(t->y),
 				       true);
 		input_report_abs(cd->input_dev, ABS_MT_TOUCH_MAJOR,
-				 __le16_to_cpu(touch_data[i].w));
+				 __le16_to_cpu(t->w));
 	}
 
 	input_mt_sync_frame(cd->input_dev);
 	input_sync(cd->input_dev);
 }
 
-static void goodix_berlin_touch_handler(struct goodix_berlin_core *cd,
-					const void *pre_buf, u32 pre_buf_len)
+static void goodix_berlin_touch_handler(struct goodix_berlin_core *cd)
 {
-	u8 buffer[GOODIX_BERLIN_IRQ_READ_LEN(GOODIX_BERLIN_MAX_TOUCH)];
-	u8 point_type, touch_num;
+	u8 touch_num;
 	int error;
 
-	/* copy pre-data to buffer */
-	memcpy(buffer, pre_buf, pre_buf_len);
-
 	touch_num = FIELD_GET(GOODIX_BERLIN_TOUCH_COUNT_MASK,
-			      buffer[GOODIX_BERLIN_REQUEST_TYPE_OFFSET]);
-
+			      cd->event.hdr.request_type);
 	if (touch_num > GOODIX_BERLIN_MAX_TOUCH) {
 		dev_warn(cd->dev, "invalid touch num %d\n", touch_num);
 		return;
 	}
 
-	if (touch_num) {
-		/* read more data if more than 2 touch events */
-		if (unlikely(touch_num > 2)) {
-			error = regmap_raw_read(cd->regmap,
-						cd->touch_data_addr + pre_buf_len,
-						&buffer[pre_buf_len],
-						(touch_num - 2) * GOODIX_BERLIN_BYTES_PER_POINT);
-			if (error) {
-				dev_err_ratelimited(cd->dev, "failed to get touch data, %d\n",
-						    error);
-				return;
-			}
-		}
-
-		point_type = FIELD_GET(GOODIX_BERLIN_POINT_TYPE_MASK,
-				       buffer[GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN]);
-
-		if (point_type == GOODIX_BERLIN_POINT_TYPE_STYLUS ||
-		    point_type == GOODIX_BERLIN_POINT_TYPE_STYLUS_HOVER) {
-			dev_warn_once(cd->dev, "Stylus event type not handled\n");
+	if (touch_num > 2) {
+		/* read additional contact data if more than 2 touch events */
+		error = goodix_berlin_get_remaining_contacts(cd, touch_num);
+		if (error)
 			return;
-		}
+	}
 
-		if (!goodix_berlin_checksum_valid(&buffer[GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN],
-						  touch_num * GOODIX_BERLIN_BYTES_PER_POINT + 2)) {
+	if (touch_num) {
+		int len = touch_num * GOODIX_BERLIN_TOUCH_SIZE +
+			  GOODIX_BERLIN_CHECKSUM_SIZE;
+		if (!goodix_berlin_checksum_valid(cd->event.data, len)) {
 			dev_err(cd->dev, "touch data checksum error: %*ph\n",
-				touch_num * GOODIX_BERLIN_BYTES_PER_POINT + 2,
-				&buffer[GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN]);
+				len, cd->event.data);
 			return;
 		}
 	}
 
-	goodix_berlin_parse_finger(cd, &buffer[GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN],
-				   touch_num);
+	goodix_berlin_report_state(cd, touch_num);
 }
 
 static int goodix_berlin_request_handle_reset(struct goodix_berlin_core *cd)
@@ -532,68 +515,72 @@ static int goodix_berlin_request_handle_reset(struct goodix_berlin_core *cd)
 static irqreturn_t goodix_berlin_irq(int irq, void *data)
 {
 	struct goodix_berlin_core *cd = data;
-	u8 buf[GOODIX_BERLIN_IRQ_READ_LEN(2)];
-	u8 event_status;
 	int error;
 
 	/*
 	 * First, read buffer with space for 2 touch events:
-	 * - GOODIX_BERLIN_IRQ_EVENT_HEAD = 8 bytes
-	 * - GOODIX_BERLIN_BYTES_PER_POINT * 2 +
-	 *   GOODIX_BERLIN_COOR_DATA_CHECKSUM = 18 bytes
+	 * - GOODIX_BERLIN_HEADER_SIZE = 8 bytes
+	 * - GOODIX_BERLIN_TOUCH_SIZE * 2 = 16 bytes
+	 * - GOODIX_BERLIN_CHECKLSUM_SIZE = 2 bytes
 	 * For a total of 26 bytes.
 	 *
-	 * If only a single finger is reported, we will read 8 bytes more than needed:
-	 * - bytes 0-7:   GOODIX_BERLIN_IRQ_EVENT_HEAD
+	 * If only a single finger is reported, we will read 8 bytes more than
+	 * needed:
+	 * - bytes 0-7:   Header (GOODIX_BERLIN_HEADER_SIZE)
 	 * - bytes 8-15:  Finger 0 Data
-	 * - bytes 16-17: GOODIX_BERLIN_COOR_DATA_CHECKSUM
+	 * - bytes 24-25: Checksum
 	 * - bytes 18-25: Unused 8 bytes
 	 *
-	 * If 2 fingers are reported, we would have read the exact needed amount of
-	 * data and checkout would be at the end of the buffer:
-	 * - bytes 0-7:	  GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN
+	 * If 2 fingers are reported, we would have read the exact needed
+	 * amount of data and checksum would be at the end of the buffer:
+	 * - bytes 0-7:   Header (GOODIX_BERLIN_HEADER_SIZE)
 	 * - bytes 8-15:  Finger 0 Bytes 0-7
 	 * - bytes 16-23: Finger 1 Bytes 0-7
-	 * - bytes 24-25: GOODIX_BERLIN_COOR_DATA_CHECKSUM
+	 * - bytes 24-25: Checksum
 	 *
-	 * If more than 2 fingers were reported, the "Checksum" bytes would in fact
-	 * contain part of the next finger data, and then we would complete the buffer
-	 * with the missing bytes, but by keeping the GOODIX_BERLIN_IRQ_READ_LEN(2)
-	 * size as base, it will still contain space for the final 2 bytes checksum:
-	 * - bytes 0-7:	  GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN]
+	 * If more than 2 fingers were reported, the "Checksum" bytes would
+	 * in fact contain part of the next finger data, and then
+	 * goodix_berlin_get_remaining_contacts() would complete the buffer
+	 * with the missing bytes, including the trailing checksum.
+	 * For example, if 3 fingers are reported, then we would do:
+	 * Read 1:
+	 * - bytes 0-7:   Header (GOODIX_BERLIN_HEADER_SIZE)
 	 * - bytes 8-15:  Finger 0 Bytes 0-7
 	 * - bytes 16-23: Finger 1 Bytes 0-7
 	 * - bytes 24-25: Finger 2 Bytes 0-1
-	 * for example if 3 fingers are reported, (3 - 2) * 8 = 8 bytes would be read:
+	 * Read 2 (with length of (3 - 2) * 8 = 8 bytes):
 	 * - bytes 26-31: Finger 2 Bytes 2-7
-	 * - bytes 32-33: GOODIX_BERLIN_COOR_DATA_CHECKSUM
+	 * - bytes 32-33: Checksum
 	 */
-	error = regmap_raw_read(cd->regmap, cd->touch_data_addr, buf,
-				GOODIX_BERLIN_IRQ_READ_LEN(2));
+	error = regmap_raw_read(cd->regmap, cd->touch_data_addr,
+				&cd->event,
+				GOODIX_BERLIN_HEADER_SIZE +
+					2 * GOODIX_BERLIN_TOUCH_SIZE +
+					GOODIX_BERLIN_CHECKSUM_SIZE);
 	if (error) {
 		dev_warn_ratelimited(cd->dev,
 				     "failed get event head data: %d\n", error);
-		return IRQ_HANDLED;
+		goto out;
 	}
 
-	if (buf[GOODIX_BERLIN_STATUS_OFFSET] == 0)
-		return IRQ_HANDLED;
+	if (cd->event.hdr.status == 0)
+		goto out;
 
-	if (!goodix_berlin_checksum_valid(buf, GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN)) {
+	if (!goodix_berlin_checksum_valid((u8 *)&cd->event.hdr,
+					  GOODIX_BERLIN_HEADER_SIZE)) {
 		dev_warn_ratelimited(cd->dev,
 				     "touch head checksum error: %*ph\n",
-				     GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN, buf);
-		return IRQ_HANDLED;
+				     (int)GOODIX_BERLIN_HEADER_SIZE,
+				     &cd->event.hdr);
+		// FIXME: should we clear the status?
+		goto out;
 	}
 
-	event_status = buf[GOODIX_BERLIN_STATUS_OFFSET];
-
-	if (event_status & GOODIX_BERLIN_TOUCH_EVENT)
-		goodix_berlin_touch_handler(cd, buf,
-					    GOODIX_BERLIN_IRQ_READ_LEN(2));
+	if (cd->event.hdr.status & GOODIX_BERLIN_TOUCH_EVENT)
+		goodix_berlin_touch_handler(cd);
 
-	if (event_status & GOODIX_BERLIN_REQUEST_EVENT) {
-		switch (buf[GOODIX_BERLIN_REQUEST_TYPE_OFFSET]) {
+	if (cd->event.hdr.status & GOODIX_BERLIN_REQUEST_EVENT) {
+		switch (cd->event.hdr.request_type) {
 		case GOODIX_BERLIN_REQUEST_CODE_RESET:
 			if (cd->reset_gpio)
 				goodix_berlin_request_handle_reset(cd);
@@ -601,13 +588,14 @@ static irqreturn_t goodix_berlin_irq(int irq, void *data)
 
 		default:
 			dev_warn(cd->dev, "unsupported request code 0x%x\n",
-				 buf[GOODIX_BERLIN_REQUEST_TYPE_OFFSET]);
+				 cd->event.hdr.request_type);
 		}
 	}
 
 	/* Clear up status field */
 	regmap_write(cd->regmap, cd->touch_data_addr, 0);
 
+out:
 	return IRQ_HANDLED;
 }
 

Re: [PATCH v14 2/4] Input: add core support for Goodix Berlin Touchscreen IC

[Neil Armstrong]

Hi Dmitry,

On 11/01/2024 08:20, Dmitry Torokhov wrote:
> Hi Neil,
> 
> On Thu, Dec 21, 2023 at 04:21:20PM +0100, Neil Armstrong wrote:
>> Add initial support for the new Goodix "Berlin" touchscreen ICs.
> 
> Thank you very much for explaining how reading of additional contacts
> and checksum works, it makes sense now.
> 
> I was a bit unhappy about number of times we copy/move the data over;
> could you please try the patch below to see if the device still works
> with it?

Sure, I'll test it and report you.

> 
> I also shortened some #defines and defines some additional structures.
> Also as far as I can see not everything needs to be packed as the data
> is naturally aligned on the word boundaries.

Great, thank!

Neil

> 
> Thanks!
> 

Re: [PATCH v14 2/4] Input: add core support for Goodix Berlin Touchscreen IC

[Neil Armstrong]

On 12/01/2024 16:08, Neil Armstrong wrote:
> Hi Dmitry,
> 
> On 11/01/2024 08:20, Dmitry Torokhov wrote:
>> Hi Neil,
>>
>> On Thu, Dec 21, 2023 at 04:21:20PM +0100, Neil Armstrong wrote:
>>> Add initial support for the new Goodix "Berlin" touchscreen ICs.
>>
>> Thank you very much for explaining how reading of additional contacts
>> and checksum works, it makes sense now.
>>
>> I was a bit unhappy about number of times we copy/move the data over;
>> could you please try the patch below to see if the device still works
>> with it?
> 
> Sure, I'll test it and report you.

Ok it still works fine!

Sending v15 with those changes and rebased on latest linux-next.

Thanks,
Neil

> 
>>
>> I also shortened some #defines and defines some additional structures.
>> Also as far as I can see not everything needs to be packed as the data
>> is naturally aligned on the word boundaries.
> 
> Great, thank!
> 
> Neil
> 
>>
>> Thanks!
>>
>