[PATCH v3 0/4] input: touchscreen: add initial support for Goodix Berlin touchscreen IC

[PATCH v3 0/4] input: touchscreen: 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 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 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: touchscreen: add core support for Goodix Berlin Touchscreen IC
      input: touchscreen: add I2C support for Goodix Berlin Touchscreen IC
      input: touchscreen: add SPI support for Goodix Berlin Touchscreen IC

 .../bindings/input/touchscreen/goodix,gt9916.yaml  |  95 ++++
 drivers/input/touchscreen/Kconfig                  |  32 ++
 drivers/input/touchscreen/Makefile                 |   3 +
 drivers/input/touchscreen/goodix_berlin.h          | 159 ++++++
 drivers/input/touchscreen/goodix_berlin_core.c     | 584 +++++++++++++++++++++
 drivers/input/touchscreen/goodix_berlin_i2c.c      |  69 +++
 drivers/input/touchscreen/goodix_berlin_spi.c      | 172 ++++++
 7 files changed, 1114 insertions(+)
---
base-commit: 6db29e14f4fb7bce9eb5290288e71b05c2b0d118
change-id: 20230606-topic-goodix-berlin-upstream-initial-ba97e8ec8f4c

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

[PATCH v3 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 v3 2/4] input: touchscreen: 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

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/input/touchscreen/Kconfig              |   5 +
 drivers/input/touchscreen/Makefile             |   1 +
 drivers/input/touchscreen/goodix_berlin.h      | 159 +++++++
 drivers/input/touchscreen/goodix_berlin_core.c | 584 +++++++++++++++++++++++++
 4 files changed, 749 insertions(+)

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index c2cbd332af1d..1a6f6f6da991 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -416,6 +416,11 @@ config TOUCHSCREEN_GOODIX
 	  To compile this driver as a module, choose M here: the
 	  module will be called goodix.
 
+config TOUCHSCREEN_GOODIX_BERLIN_CORE
+	depends on GPIOLIB || COMPILE_TEST
+	depends on REGMAP
+	tristate
+
 config TOUCHSCREEN_HIDEEP
 	tristate "HiDeep Touch IC"
 	depends on I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 159cd5136fdb..29cdb042e104 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..235f44947a28
--- /dev/null
+++ b/drivers/input/touchscreen/goodix_berlin.h
@@ -0,0 +1,159 @@
+/* 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/gpio/consumer.h>
+#include <linux/input.h>
+#include <linux/input/touchscreen.h>
+#include <linux/regulator/consumer.h>
+#include <linux/sizes.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;
+};
+
+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..af3e73bbb3ec
--- /dev/null
+++ b/drivers/input/touchscreen/goodix_berlin_core.c
@@ -0,0 +1,584 @@
+// 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_ts_berlin driver.
+ */
+#include <asm/unaligned.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/regmap.h>
+
+#include "goodix_berlin.h"
+
+/*
+ * Goodix "Berlin" Touchscreen ID 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 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)
+ */
+
+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];
+
+	r_checksum = get_unaligned_le16(&data[i]);
+
+	return FIELD_GET(GOODIX_BERLIN_COOR_DATA_CHECKSUM_MASK, 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", 8, rx_buf);
+
+	return -EINVAL;
+}
+
+static int goodix_berlin_power_on(struct goodix_berlin_core *cd, bool on)
+{
+	int error = 0;
+
+	if (on) {
+		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 error_avdd_regulator;
+		}
+
+		/* Vendor waits 15ms for IOVDD to settle */
+		usleep_range(15000, 15100);
+
+		gpiod_set_value(cd->reset_gpio, 0);
+
+		/* Vendor waits 4ms for Firmware to initialize */
+		usleep_range(4000, 4100);
+
+		error = goodix_berlin_dev_confirm(cd);
+		if (error)
+			goto error_dev_confirm;
+
+		/* Vendor waits 100ms for Firmware to fully boot */
+		msleep(GOODIX_BERLIN_NORMAL_RESET_DELAY_MS);
+
+		return 0;
+	}
+
+error_dev_confirm:
+	gpiod_set_value(cd->reset_gpio, 1);
+
+	regulator_disable(cd->avdd);
+
+error_avdd_regulator:
+	regulator_disable(cd->iovdd);
+
+	return error;
+}
+
+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\n");
+		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[GOODIX_BERLIN_IC_INFO_MAX_LEN];
+	__le16 length_raw;
+	u16 length;
+	int error;
+
+	error = regmap_raw_read(cd->regmap, GOODIX_BERLIN_IC_INFO_ADDR,
+				&length_raw, sizeof(length_raw));
+	if (error) {
+		dev_info(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_info(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_info(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, (const uint8_t *)afe_data, length)) {
+		dev_err(cd->dev, "fw info data invalid\n");
+		return -EINVAL;
+	}
+
+	if (!goodix_berlin_checksum_valid((const uint8_t *)afe_data, length)) {
+		dev_info(cd->dev, "fw info checksum error\n");
+		return -EINVAL;
+	}
+
+	error = goodix_berlin_convert_ic_info(cd, afe_data, length);
+	if (error) {
+		dev_err(cd->dev, "error converting ic info\n");
+		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;
+
+	/* Check for data validity */
+	for (i = 0; i < touch_num; i++) {
+		unsigned int id;
+
+		id = FIELD_GET(GOODIX_BERLIN_TOUCH_ID_MASK, touch_data[i].id);
+
+		if (id >= GOODIX_BERLIN_MAX_TOUCH) {
+			dev_warn(cd->dev, "invalid finger id %d\n", id);
+			return;
+		}
+	}
+
+	/* Report finger touches */
+	for (i = 0; i < touch_num; i++) {
+		input_mt_slot(cd->input_dev,
+			      FIELD_GET(GOODIX_BERLIN_TOUCH_ID_MASK,
+					touch_data[i].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)
+{
+	static u8 buffer[GOODIX_BERLIN_IRQ_READ_LEN(GOODIX_BERLIN_MAX_TOUCH)];
+	u8 point_type = 0;
+	u8 touch_num = 0;
+	int error = 0;
+
+	/* 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 get touch data\n");
+				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_dbg(cd->dev, "touch data checksum error\n");
+			dev_dbg(cd->dev, "data: %*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(cd->reset_gpio, 1);
+	usleep_range(2000, 2100);
+	gpiod_set_value(cd->reset_gpio, 0);
+
+	msleep(GOODIX_BERLIN_NORMAL_RESET_DELAY_MS);
+
+	return 0;
+}
+
+static irqreturn_t goodix_berlin_threadirq_func(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 */
+	error = regmap_raw_read(cd->regmap, cd->touch_data_addr, buf,
+				GOODIX_BERLIN_IRQ_READ_LEN(2));
+	if (error) {
+		dev_err_ratelimited(cd->dev, "failed get event head data\n");
+		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 err : %*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:
+			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;
+
+	return input_register_device(cd->input_dev);
+}
+
+static int goodix_berlin_pm_suspend(struct device *dev)
+{
+	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
+
+	disable_irq(cd->irq);
+
+	return goodix_berlin_power_on(cd, false);
+}
+
+static int goodix_berlin_pm_resume(struct device *dev)
+{
+	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
+	int error;
+
+	error = goodix_berlin_power_on(cd, true);
+	if (error)
+		return error;
+
+	enable_irq(cd->irq);
+
+	return 0;
+}
+
+EXPORT_GPL_SIMPLE_DEV_PM_OPS(goodix_berlin_pm_ops,
+			     goodix_berlin_pm_suspend,
+			     goodix_berlin_pm_resume);
+
+static void goodix_berlin_power_off(void *data)
+{
+	struct goodix_berlin_core *cd = data;
+
+	goodix_berlin_power_on(cd, false);
+}
+
+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, true);
+	if (error) {
+		dev_err(dev, "failed power on");
+		return error;
+	}
+
+	error = devm_add_action_or_reset(dev, goodix_berlin_power_off, 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, irq, NULL,
+					  goodix_berlin_threadirq_func,
+					  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 v3 3/4] input: touchscreen: 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

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 1a6f6f6da991..5e21cca6025d 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -421,6 +421,20 @@ config TOUCHSCREEN_GOODIX_BERLIN_CORE
 	depends on REGMAP
 	tristate
 
+config TOUCHSCREEN_GOODIX_BERLIN_I2C
+	tristate "Goodix Berlin I2C touchscreen"
+	depends on I2C
+	depends on 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 29cdb042e104..921a2da0c2be 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

[PATCH v3 4/4] input: touchscreen: 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

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/input/touchscreen/Kconfig             |  13 ++
 drivers/input/touchscreen/Makefile            |   1 +
 drivers/input/touchscreen/goodix_berlin_spi.c | 172 ++++++++++++++++++++++++++
 3 files changed, 186 insertions(+)

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 5e21cca6025d..2d86615e5090 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -435,6 +435,19 @@ 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 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 921a2da0c2be..29524e8a83db 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..3a1bc251b32d
--- /dev/null
+++ b/drivers/input/touchscreen/goodix_berlin_spi.c
@@ -0,0 +1,172 @@
+// 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 "goodix_berlin.h"
+
+#define SPI_TRANS_PREFIX_LEN	1
+#define REGISTER_WIDTH		4
+#define SPI_READ_DUMMY_LEN	3
+#define SPI_READ_PREFIX_LEN	(SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH + SPI_READ_DUMMY_LEN)
+#define SPI_WRITE_PREFIX_LEN	(SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH)
+
+#define SPI_WRITE_FLAG		0xF0
+#define 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 ret;
+
+	if (reg_size != REGISTER_WIDTH)
+		return -EINVAL;
+
+	buf = kzalloc(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] = SPI_READ_FLAG;
+	put_unaligned_be32(*reg, buf + SPI_TRANS_PREFIX_LEN);
+	memset(buf + SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH, 0xff,
+	       SPI_READ_DUMMY_LEN);
+
+	xfers.tx_buf = buf;
+	xfers.rx_buf = buf;
+	xfers.len = SPI_READ_PREFIX_LEN + val_size;
+	xfers.cs_change = 0;
+	spi_message_add_tail(&xfers, &spi_msg);
+
+	ret = spi_sync(spi, &spi_msg);
+	if (ret < 0)
+		dev_err(&spi->dev, "transfer error:%d", ret);
+	else
+		memcpy(val_buf, buf + SPI_READ_PREFIX_LEN, val_size);
+
+	kfree(buf);
+	return ret;
+}
+
+static int goodix_berlin_spi_write(void *context, const void *data,
+				   size_t count)
+{
+	unsigned int len = count - 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 ret;
+
+	buf = kzalloc(SPI_WRITE_PREFIX_LEN + len, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	spi_message_init(&spi_msg);
+	memset(&xfers, 0, sizeof(xfers));
+
+	buf[0] = SPI_WRITE_FLAG;
+	put_unaligned_be32(*reg, buf + SPI_TRANS_PREFIX_LEN);
+	memcpy(buf + SPI_WRITE_PREFIX_LEN, data + REGISTER_WIDTH, len);
+
+	xfers.tx_buf = buf;
+	xfers.len = SPI_WRITE_PREFIX_LEN + len;
+	xfers.cs_change = 0;
+	spi_message_add_tail(&xfers, &spi_msg);
+
+	ret = spi_sync(spi, &spi_msg);
+	if (ret < 0)
+		dev_err(&spi->dev, "transfer error:%d", ret);
+
+	kfree(buf);
+	return ret;
+}
+
+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;
+
+	regmap_config = devm_kmemdup(&spi->dev, &goodix_berlin_spi_regmap_conf,
+				     sizeof(*regmap_config), GFP_KERNEL);
+	if (!regmap_config)
+		return -ENOMEM;
+
+	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->max_raw_read = max_size - SPI_READ_PREFIX_LEN;
+	regmap_config->max_raw_write = max_size - SPI_WRITE_PREFIX_LEN;
+
+	regmap = devm_regmap_init(&spi->dev, NULL, spi, regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	return goodix_berlin_probe(&spi->dev, spi->irq,
+				   &goodix_berlin_spi_input_id, regmap);
+}
+
+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 v3 2/4] input: touchscreen: add core support for Goodix Berlin Touchscreen IC

[Jeff LaBundy]

Hi Neil,

On Thu, Jun 22, 2023 at 04:29:00PM +0200, Neil Armstrong wrote:
> 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
> 
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---

Great work; thank you for the productive discussion. I only had some
minor cosmetic comments this last time; once those are addressed, feel
free to add:

Reviewed-by: Jeff LaBundy <jeff@labundy.com>

>  drivers/input/touchscreen/Kconfig              |   5 +
>  drivers/input/touchscreen/Makefile             |   1 +
>  drivers/input/touchscreen/goodix_berlin.h      | 159 +++++++
>  drivers/input/touchscreen/goodix_berlin_core.c | 584 +++++++++++++++++++++++++
>  4 files changed, 749 insertions(+)
> 
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index c2cbd332af1d..1a6f6f6da991 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -416,6 +416,11 @@ config TOUCHSCREEN_GOODIX
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called goodix.
>  
> +config TOUCHSCREEN_GOODIX_BERLIN_CORE
> +	depends on GPIOLIB || COMPILE_TEST

My comment seems to have been missed; this driver does not actually depend
on GPIOLIB and the dependency here can be dropped. However, this would leave
the driver to be built only if COMPILE_TEST is set which is obviously not
what we want. Therefore, this line can simply be dropped entirely.

> +	depends on REGMAP

Rather than depending on REGMAP here, you should simply select the appropriate
transport from the I2C or SPI driver (which seems to have been missed in those
patches as well; I will follow up there). In the meantime, this line can just
be dropped.

MFD has several examples of dual I2C/SPI devices that demonstrate the correct
pattern; see any of those for reference.

> +	tristate
> +
>  config TOUCHSCREEN_HIDEEP
>  	tristate "HiDeep Touch IC"
>  	depends on I2C
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 159cd5136fdb..29cdb042e104 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..235f44947a28
> --- /dev/null
> +++ b/drivers/input/touchscreen/goodix_berlin.h
> @@ -0,0 +1,159 @@
> +/* 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/gpio/consumer.h>
> +#include <linux/input.h>
> +#include <linux/input/touchscreen.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/sizes.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;
> +};
> +
> +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..af3e73bbb3ec
> --- /dev/null
> +++ b/drivers/input/touchscreen/goodix_berlin_core.c
> @@ -0,0 +1,584 @@
> +// 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_ts_berlin driver.
> + */
> +#include <asm/unaligned.h>
> +#include <linux/input/mt.h>
> +#include <linux/input/touchscreen.h>
> +#include <linux/regmap.h>
> +
> +#include "goodix_berlin.h"
> +
> +/*
> + * Goodix "Berlin" Touchscreen ID 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 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)
> + */
> +
> +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];
> +
> +	r_checksum = get_unaligned_le16(&data[i]);
> +
> +	return FIELD_GET(GOODIX_BERLIN_COOR_DATA_CHECKSUM_MASK, 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", 8, rx_buf);
> +
> +	return -EINVAL;
> +}
> +
> +static int goodix_berlin_power_on(struct goodix_berlin_core *cd, bool on)
> +{
> +	int error = 0;
> +
> +	if (on) {
> +		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 error_avdd_regulator;
> +		}
> +
> +		/* Vendor waits 15ms for IOVDD to settle */
> +		usleep_range(15000, 15100);
> +
> +		gpiod_set_value(cd->reset_gpio, 0);
> +
> +		/* Vendor waits 4ms for Firmware to initialize */
> +		usleep_range(4000, 4100);
> +
> +		error = goodix_berlin_dev_confirm(cd);
> +		if (error)
> +			goto error_dev_confirm;
> +
> +		/* Vendor waits 100ms for Firmware to fully boot */
> +		msleep(GOODIX_BERLIN_NORMAL_RESET_DELAY_MS);
> +
> +		return 0;
> +	}
> +
> +error_dev_confirm:
> +	gpiod_set_value(cd->reset_gpio, 1);

These labels are still confusing in my opinion. Rather than name the label
based on the code that could have gotten us here, it is better for the name
to reflect the action that follows.

How about err_dev_reset and err_iovdd_disable?

> +
> +	regulator_disable(cd->avdd);
> +
> +error_avdd_regulator:
> +	regulator_disable(cd->iovdd);
> +
> +	return error;
> +}
> +
> +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\n");

It's handy to print the return value here as you do elsewhere.

> +		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[GOODIX_BERLIN_IC_INFO_MAX_LEN];
> +	__le16 length_raw;
> +	u16 length;
> +	int error;
> +
> +	error = regmap_raw_read(cd->regmap, GOODIX_BERLIN_IC_INFO_ADDR,
> +				&length_raw, sizeof(length_raw));
> +	if (error) {
> +		dev_info(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_info(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_info(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, (const uint8_t *)afe_data, length)) {
> +		dev_err(cd->dev, "fw info data invalid\n");
> +		return -EINVAL;
> +	}
> +
> +	if (!goodix_berlin_checksum_valid((const uint8_t *)afe_data, length)) {
> +		dev_info(cd->dev, "fw info checksum error\n");
> +		return -EINVAL;
> +	}
> +
> +	error = goodix_berlin_convert_ic_info(cd, afe_data, length);
> +	if (error) {
> +		dev_err(cd->dev, "error converting ic info\n");

This function already prints an error message upon failure; consider dropping
one of the two.

> +		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;
> +
> +	/* Check for data validity */
> +	for (i = 0; i < touch_num; i++) {
> +		unsigned int id;
> +
> +		id = FIELD_GET(GOODIX_BERLIN_TOUCH_ID_MASK, touch_data[i].id);
> +
> +		if (id >= GOODIX_BERLIN_MAX_TOUCH) {
> +			dev_warn(cd->dev, "invalid finger id %d\n", id);
> +			return;
> +		}
> +	}
> +
> +	/* Report finger touches */
> +	for (i = 0; i < touch_num; i++) {
> +		input_mt_slot(cd->input_dev,
> +			      FIELD_GET(GOODIX_BERLIN_TOUCH_ID_MASK,
> +					touch_data[i].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)
> +{
> +	static u8 buffer[GOODIX_BERLIN_IRQ_READ_LEN(GOODIX_BERLIN_MAX_TOUCH)];
> +	u8 point_type = 0;
> +	u8 touch_num = 0;
> +	int error = 0;

Nit: some more unnecessary initializations in here. All of this cleaned up
quite nicely however.

> +
> +	/* 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 get touch data\n");

failed to get touch data: %d

(insert the word "to" and print the return value)

> +				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_dbg(cd->dev, "touch data checksum error\n");
> +			dev_dbg(cd->dev, "data: %*ph\n",
> +				touch_num * GOODIX_BERLIN_BYTES_PER_POINT + 2,
> +				&buffer[GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN]);

This case seems worth of a dev_err; the two messages can be combined as well.

> +			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(cd->reset_gpio, 1);
> +	usleep_range(2000, 2100);
> +	gpiod_set_value(cd->reset_gpio, 0);
> +
> +	msleep(GOODIX_BERLIN_NORMAL_RESET_DELAY_MS);
> +
> +	return 0;
> +}
> +
> +static irqreturn_t goodix_berlin_threadirq_func(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 */
> +	error = regmap_raw_read(cd->regmap, cd->touch_data_addr, buf,
> +				GOODIX_BERLIN_IRQ_READ_LEN(2));
> +	if (error) {
> +		dev_err_ratelimited(cd->dev, "failed get event head data\n");

failed to get event head data: %d

(same comment as earlier)

> +		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 err : %*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:
> +			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;
> +
> +	return input_register_device(cd->input_dev);
> +}
> +
> +static int goodix_berlin_pm_suspend(struct device *dev)
> +{
> +	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
> +
> +	disable_irq(cd->irq);
> +
> +	return goodix_berlin_power_on(cd, false);
> +}
> +
> +static int goodix_berlin_pm_resume(struct device *dev)
> +{
> +	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
> +	int error;
> +
> +	error = goodix_berlin_power_on(cd, true);
> +	if (error)
> +		return error;
> +
> +	enable_irq(cd->irq);
> +
> +	return 0;
> +}
> +
> +EXPORT_GPL_SIMPLE_DEV_PM_OPS(goodix_berlin_pm_ops,
> +			     goodix_berlin_pm_suspend,
> +			     goodix_berlin_pm_resume);
> +
> +static void goodix_berlin_power_off(void *data)
> +{
> +	struct goodix_berlin_core *cd = data;
> +
> +	goodix_berlin_power_on(cd, false);
> +}
> +
> +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, true);
> +	if (error) {
> +		dev_err(dev, "failed power on");
> +		return error;
> +	}
> +
> +	error = devm_add_action_or_reset(dev, goodix_berlin_power_off, 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, irq, NULL,
> +					  goodix_berlin_threadirq_func,
> +					  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
> 

Kind regards,
Jeff LaBundy

Re: [PATCH v3 3/4] input: touchscreen: add I2C support for Goodix Berlin Touchscreen IC

[Jeff LaBundy]

Hi Neil,

On Thu, Jun 22, 2023 at 04:29:01PM +0200, Neil Armstrong wrote:
> 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
> 
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---

Just one comment below, then feel free to add:

Reviewed-by: Jeff LaBundy <jeff@labundy.com>

>  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 1a6f6f6da991..5e21cca6025d 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -421,6 +421,20 @@ config TOUCHSCREEN_GOODIX_BERLIN_CORE
>  	depends on REGMAP
>  	tristate
>  
> +config TOUCHSCREEN_GOODIX_BERLIN_I2C
> +	tristate "Goodix Berlin I2C touchscreen"
> +	depends on I2C
> +	depends on REGMAP_I2C

select REGMAP_I2C

(keep "depends on 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 29cdb042e104..921a2da0c2be 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
> 

Kind regards,
Jeff LaBundy

Re: [PATCH v3 4/4] input: touchscreen: add SPI support for Goodix Berlin Touchscreen IC

[Jeff LaBundy]

Hi Neil,

On Thu, Jun 22, 2023 at 04:29:02PM +0200, Neil Armstrong wrote:
> 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
> 
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---

Just a few comments below, then feel free to add:

Reviewed-by: Jeff LaBundy <jeff@labundy.com>

>  drivers/input/touchscreen/Kconfig             |  13 ++
>  drivers/input/touchscreen/Makefile            |   1 +
>  drivers/input/touchscreen/goodix_berlin_spi.c | 172 ++++++++++++++++++++++++++
>  3 files changed, 186 insertions(+)
> 
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 5e21cca6025d..2d86615e5090 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -435,6 +435,19 @@ 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

(keep "depends on SPI_MASTER")

> +	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 921a2da0c2be..29524e8a83db 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..3a1bc251b32d
> --- /dev/null
> +++ b/drivers/input/touchscreen/goodix_berlin_spi.c
> @@ -0,0 +1,172 @@
> +// 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 "goodix_berlin.h"
> +
> +#define SPI_TRANS_PREFIX_LEN	1
> +#define REGISTER_WIDTH		4
> +#define SPI_READ_DUMMY_LEN	3
> +#define SPI_READ_PREFIX_LEN	(SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH + SPI_READ_DUMMY_LEN)
> +#define SPI_WRITE_PREFIX_LEN	(SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH)
> +
> +#define SPI_WRITE_FLAG		0xF0
> +#define SPI_READ_FLAG		0xF1

Please namespace all of these as you have done in the core driver.

> +
> +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 ret;

	int error;

> +
> +	if (reg_size != REGISTER_WIDTH)
> +		return -EINVAL;
> +
> +	buf = kzalloc(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] = SPI_READ_FLAG;
> +	put_unaligned_be32(*reg, buf + SPI_TRANS_PREFIX_LEN);
> +	memset(buf + SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH, 0xff,
> +	       SPI_READ_DUMMY_LEN);
> +
> +	xfers.tx_buf = buf;
> +	xfers.rx_buf = buf;
> +	xfers.len = SPI_READ_PREFIX_LEN + val_size;
> +	xfers.cs_change = 0;
> +	spi_message_add_tail(&xfers, &spi_msg);
> +
> +	ret = spi_sync(spi, &spi_msg);

	error = spi_sync(...);

> +	if (ret < 0)

	if (error)

> +		dev_err(&spi->dev, "transfer error:%d", ret);
> +	else
> +		memcpy(val_buf, buf + SPI_READ_PREFIX_LEN, val_size);
> +
> +	kfree(buf);
> +	return ret;
> +}
> +
> +static int goodix_berlin_spi_write(void *context, const void *data,
> +				   size_t count)
> +{
> +	unsigned int len = count - 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 ret;

Same comments here regarding 'error' vs. 'ret'.

> +
> +	buf = kzalloc(SPI_WRITE_PREFIX_LEN + len, GFP_KERNEL);
> +	if (!buf)
> +		return -ENOMEM;
> +
> +	spi_message_init(&spi_msg);
> +	memset(&xfers, 0, sizeof(xfers));
> +
> +	buf[0] = SPI_WRITE_FLAG;
> +	put_unaligned_be32(*reg, buf + SPI_TRANS_PREFIX_LEN);
> +	memcpy(buf + SPI_WRITE_PREFIX_LEN, data + REGISTER_WIDTH, len);
> +
> +	xfers.tx_buf = buf;
> +	xfers.len = SPI_WRITE_PREFIX_LEN + len;
> +	xfers.cs_change = 0;
> +	spi_message_add_tail(&xfers, &spi_msg);
> +
> +	ret = spi_sync(spi, &spi_msg);
> +	if (ret < 0)
> +		dev_err(&spi->dev, "transfer error:%d", ret);
> +
> +	kfree(buf);
> +	return ret;
> +}
> +
> +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;
> +
> +	regmap_config = devm_kmemdup(&spi->dev, &goodix_berlin_spi_regmap_conf,
> +				     sizeof(*regmap_config), GFP_KERNEL);
> +	if (!regmap_config)
> +		return -ENOMEM;

Is there any reason we cannot simply pass goodix_berlin_spi_regmap_conf to
devm_regmap_init() below? Why to duplicate and pass the copy?

For reference, BMP280 in IIO is a similar example of a device with regmap
sitting atop a bespoke SPI protocol; it does not seem to take this extra
step.

> +
> +	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->max_raw_read = max_size - SPI_READ_PREFIX_LEN;
> +	regmap_config->max_raw_write = max_size - SPI_WRITE_PREFIX_LEN;
> +
> +	regmap = devm_regmap_init(&spi->dev, NULL, spi, regmap_config);
> +	if (IS_ERR(regmap))
> +		return PTR_ERR(regmap);
> +
> +	return goodix_berlin_probe(&spi->dev, spi->irq,
> +				   &goodix_berlin_spi_input_id, regmap);
> +}
> +
> +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
> 

Kind regards,
Jeff LaBundy

Re: [PATCH v3 2/4] input: touchscreen: add core support for Goodix Berlin Touchscreen IC

[Neil Armstrong]

On 25/06/2023 21:14, Jeff LaBundy wrote:
> Hi Neil,
> 
> On Thu, Jun 22, 2023 at 04:29:00PM +0200, Neil Armstrong wrote:
>> 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
>>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
> 
> Great work; thank you for the productive discussion. I only had some
> minor cosmetic comments this last time; once those are addressed, feel
> free to add:
> 
> Reviewed-by: Jeff LaBundy <jeff@labundy.com>

Thanks a lot for you reviews!

> 
>>   drivers/input/touchscreen/Kconfig              |   5 +
>>   drivers/input/touchscreen/Makefile             |   1 +
>>   drivers/input/touchscreen/goodix_berlin.h      | 159 +++++++
>>   drivers/input/touchscreen/goodix_berlin_core.c | 584 +++++++++++++++++++++++++
>>   4 files changed, 749 insertions(+)
>>
>> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
>> index c2cbd332af1d..1a6f6f6da991 100644
>> --- a/drivers/input/touchscreen/Kconfig
>> +++ b/drivers/input/touchscreen/Kconfig
>> @@ -416,6 +416,11 @@ config TOUCHSCREEN_GOODIX
>>   	  To compile this driver as a module, choose M here: the
>>   	  module will be called goodix.
>>   
>> +config TOUCHSCREEN_GOODIX_BERLIN_CORE
>> +	depends on GPIOLIB || COMPILE_TEST
> 
> My comment seems to have been missed; this driver does not actually depend
> on GPIOLIB and the dependency here can be dropped. However, this would leave
> the driver to be built only if COMPILE_TEST is set which is obviously not
> what we want. Therefore, this line can simply be dropped entirely.


Indeed, I forgot to change this thx for the reminder.

> 
>> +	depends on REGMAP
> 
> Rather than depending on REGMAP here, you should simply select the appropriate
> transport from the I2C or SPI driver (which seems to have been missed in those
> patches as well; I will follow up there). In the meantime, this line can just
> be dropped.
> 
> MFD has several examples of dual I2C/SPI devices that demonstrate the correct
> pattern; see any of those for reference.

Ack, I'll update this and the i2c/spi entries aswell as you pointed.

> 
>> +	tristate
>> +
>>   config TOUCHSCREEN_HIDEEP
>>   	tristate "HiDeep Touch IC"
>>   	depends on I2C
>> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
>> index 159cd5136fdb..29cdb042e104 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..235f44947a28
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/goodix_berlin.h
>> @@ -0,0 +1,159 @@
>> +/* 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/gpio/consumer.h>
>> +#include <linux/input.h>
>> +#include <linux/input/touchscreen.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/sizes.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;
>> +};
>> +
>> +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..af3e73bbb3ec
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/goodix_berlin_core.c
>> @@ -0,0 +1,584 @@
>> +// 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_ts_berlin driver.
>> + */
>> +#include <asm/unaligned.h>
>> +#include <linux/input/mt.h>
>> +#include <linux/input/touchscreen.h>
>> +#include <linux/regmap.h>
>> +
>> +#include "goodix_berlin.h"
>> +
>> +/*
>> + * Goodix "Berlin" Touchscreen ID 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 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)
>> + */
>> +
>> +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];
>> +
>> +	r_checksum = get_unaligned_le16(&data[i]);
>> +
>> +	return FIELD_GET(GOODIX_BERLIN_COOR_DATA_CHECKSUM_MASK, 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", 8, rx_buf);
>> +
>> +	return -EINVAL;
>> +}
>> +
>> +static int goodix_berlin_power_on(struct goodix_berlin_core *cd, bool on)
>> +{
>> +	int error = 0;
>> +
>> +	if (on) {
>> +		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 error_avdd_regulator;
>> +		}
>> +
>> +		/* Vendor waits 15ms for IOVDD to settle */
>> +		usleep_range(15000, 15100);
>> +
>> +		gpiod_set_value(cd->reset_gpio, 0);
>> +
>> +		/* Vendor waits 4ms for Firmware to initialize */
>> +		usleep_range(4000, 4100);
>> +
>> +		error = goodix_berlin_dev_confirm(cd);
>> +		if (error)
>> +			goto error_dev_confirm;
>> +
>> +		/* Vendor waits 100ms for Firmware to fully boot */
>> +		msleep(GOODIX_BERLIN_NORMAL_RESET_DELAY_MS);
>> +
>> +		return 0;
>> +	}
>> +
>> +error_dev_confirm:
>> +	gpiod_set_value(cd->reset_gpio, 1);
> 
> These labels are still confusing in my opinion. Rather than name the label
> based on the code that could have gotten us here, it is better for the name
> to reflect the action that follows.
> 
> How about err_dev_reset and err_iovdd_disable?

Ack, I wasn't sure in which way those should be names

>> +
>> +	regulator_disable(cd->avdd);
>> +
>> +error_avdd_regulator:
>> +	regulator_disable(cd->iovdd);
>> +
>> +	return error;
>> +}
>> +
>> +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\n");
> 
> It's handy to print the return value here as you do elsewhere.

Ack

> 
>> +		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[GOODIX_BERLIN_IC_INFO_MAX_LEN];
>> +	__le16 length_raw;
>> +	u16 length;
>> +	int error;
>> +
>> +	error = regmap_raw_read(cd->regmap, GOODIX_BERLIN_IC_INFO_ADDR,
>> +				&length_raw, sizeof(length_raw));
>> +	if (error) {
>> +		dev_info(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_info(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_info(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, (const uint8_t *)afe_data, length)) {
>> +		dev_err(cd->dev, "fw info data invalid\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (!goodix_berlin_checksum_valid((const uint8_t *)afe_data, length)) {
>> +		dev_info(cd->dev, "fw info checksum error\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	error = goodix_berlin_convert_ic_info(cd, afe_data, length);
>> +	if (error) {
>> +		dev_err(cd->dev, "error converting ic info\n");
> 
> This function already prints an error message upon failure; consider dropping
> one of the two.

Ack

> 
>> +		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;
>> +
>> +	/* Check for data validity */
>> +	for (i = 0; i < touch_num; i++) {
>> +		unsigned int id;
>> +
>> +		id = FIELD_GET(GOODIX_BERLIN_TOUCH_ID_MASK, touch_data[i].id);
>> +
>> +		if (id >= GOODIX_BERLIN_MAX_TOUCH) {
>> +			dev_warn(cd->dev, "invalid finger id %d\n", id);
>> +			return;
>> +		}
>> +	}
>> +
>> +	/* Report finger touches */
>> +	for (i = 0; i < touch_num; i++) {
>> +		input_mt_slot(cd->input_dev,
>> +			      FIELD_GET(GOODIX_BERLIN_TOUCH_ID_MASK,
>> +					touch_data[i].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)
>> +{
>> +	static u8 buffer[GOODIX_BERLIN_IRQ_READ_LEN(GOODIX_BERLIN_MAX_TOUCH)];
>> +	u8 point_type = 0;
>> +	u8 touch_num = 0;
>> +	int error = 0;
> 
> Nit: some more unnecessary initializations in here. All of this cleaned up
> quite nicely however.

Ack, forgot those in the refactor

> 
>> +
>> +	/* 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 get touch data\n");
> 
> failed to get touch data: %d
> 
> (insert the word "to" and print the return value)

Ack

> 
>> +				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_dbg(cd->dev, "touch data checksum error\n");
>> +			dev_dbg(cd->dev, "data: %*ph\n",
>> +				touch_num * GOODIX_BERLIN_BYTES_PER_POINT + 2,
>> +				&buffer[GOODIX_BERLIN_IRQ_EVENT_HEAD_LEN]);
> 
> This case seems worth of a dev_err; the two messages can be combined as well.

Yep

> 
>> +			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(cd->reset_gpio, 1);
>> +	usleep_range(2000, 2100);
>> +	gpiod_set_value(cd->reset_gpio, 0);
>> +
>> +	msleep(GOODIX_BERLIN_NORMAL_RESET_DELAY_MS);
>> +
>> +	return 0;
>> +}
>> +
>> +static irqreturn_t goodix_berlin_threadirq_func(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 */
>> +	error = regmap_raw_read(cd->regmap, cd->touch_data_addr, buf,
>> +				GOODIX_BERLIN_IRQ_READ_LEN(2));
>> +	if (error) {
>> +		dev_err_ratelimited(cd->dev, "failed get event head data\n");
> 
> failed to get event head data: %d
> 
> (same comment as earlier)
> 

Ack

>> +		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 err : %*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:
>> +			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;
>> +
>> +	return input_register_device(cd->input_dev);
>> +}
>> +
>> +static int goodix_berlin_pm_suspend(struct device *dev)
>> +{
>> +	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
>> +
>> +	disable_irq(cd->irq);
>> +
>> +	return goodix_berlin_power_on(cd, false);
>> +}
>> +
>> +static int goodix_berlin_pm_resume(struct device *dev)
>> +{
>> +	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
>> +	int error;
>> +
>> +	error = goodix_berlin_power_on(cd, true);
>> +	if (error)
>> +		return error;
>> +
>> +	enable_irq(cd->irq);
>> +
>> +	return 0;
>> +}
>> +
>> +EXPORT_GPL_SIMPLE_DEV_PM_OPS(goodix_berlin_pm_ops,
>> +			     goodix_berlin_pm_suspend,
>> +			     goodix_berlin_pm_resume);
>> +
>> +static void goodix_berlin_power_off(void *data)
>> +{
>> +	struct goodix_berlin_core *cd = data;
>> +
>> +	goodix_berlin_power_on(cd, false);
>> +}
>> +
>> +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, true);
>> +	if (error) {
>> +		dev_err(dev, "failed power on");
>> +		return error;
>> +	}
>> +
>> +	error = devm_add_action_or_reset(dev, goodix_berlin_power_off, 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, irq, NULL,
>> +					  goodix_berlin_threadirq_func,
>> +					  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
>>
> 
> Kind regards,
> Jeff LaBundy

Thanks,
Neil

Re: [PATCH v3 3/4] input: touchscreen: add I2C support for Goodix Berlin Touchscreen IC

[Neil Armstrong]

Hi Jeff,

On 25/06/2023 21:17, Jeff LaBundy wrote:
> Hi Neil,
> 
> On Thu, Jun 22, 2023 at 04:29:01PM +0200, Neil Armstrong wrote:
>> 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
>>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
> 
> Just one comment below, then feel free to add:
> 
> Reviewed-by: Jeff LaBundy <jeff@labundy.com>
> 
>>   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 1a6f6f6da991..5e21cca6025d 100644
>> --- a/drivers/input/touchscreen/Kconfig
>> +++ b/drivers/input/touchscreen/Kconfig
>> @@ -421,6 +421,20 @@ config TOUCHSCREEN_GOODIX_BERLIN_CORE
>>   	depends on REGMAP
>>   	tristate
>>   
>> +config TOUCHSCREEN_GOODIX_BERLIN_I2C
>> +	tristate "Goodix Berlin I2C touchscreen"
>> +	depends on I2C
>> +	depends on REGMAP_I2C
> 
> select REGMAP_I2C
> 
> (keep "depends on I2C")

Good point,

Thanks,
Neil

> 
>> +	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 29cdb042e104..921a2da0c2be 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
>>
> 
> Kind regards,
> Jeff LaBundy

Re: [PATCH v3 4/4] input: touchscreen: add SPI support for Goodix Berlin Touchscreen IC

[Neil Armstrong]

Hi Jeff,

On 25/06/2023 21:38, Jeff LaBundy wrote:
> Hi Neil,
> 
> On Thu, Jun 22, 2023 at 04:29:02PM +0200, Neil Armstrong wrote:
>> 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
>>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
> 
> Just a few comments below, then feel free to add:
> 
> Reviewed-by: Jeff LaBundy <jeff@labundy.com>
> 
>>   drivers/input/touchscreen/Kconfig             |  13 ++
>>   drivers/input/touchscreen/Makefile            |   1 +
>>   drivers/input/touchscreen/goodix_berlin_spi.c | 172 ++++++++++++++++++++++++++
>>   3 files changed, 186 insertions(+)
>>
>> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
>> index 5e21cca6025d..2d86615e5090 100644
>> --- a/drivers/input/touchscreen/Kconfig
>> +++ b/drivers/input/touchscreen/Kconfig
>> @@ -435,6 +435,19 @@ 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
> 
> (keep "depends on SPI_MASTER")

Ack, indeed it looks cleaner to do that

> 
>> +	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 921a2da0c2be..29524e8a83db 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..3a1bc251b32d
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/goodix_berlin_spi.c
>> @@ -0,0 +1,172 @@
>> +// 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 "goodix_berlin.h"
>> +
>> +#define SPI_TRANS_PREFIX_LEN	1
>> +#define REGISTER_WIDTH		4
>> +#define SPI_READ_DUMMY_LEN	3
>> +#define SPI_READ_PREFIX_LEN	(SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH + SPI_READ_DUMMY_LEN)
>> +#define SPI_WRITE_PREFIX_LEN	(SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH)
>> +
>> +#define SPI_WRITE_FLAG		0xF0
>> +#define SPI_READ_FLAG		0xF1
> 
> Please namespace all of these as you have done in the core driver.

Ack

> 
>> +
>> +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 ret;
> 
> 	int error;
> 
>> +
>> +	if (reg_size != REGISTER_WIDTH)
>> +		return -EINVAL;
>> +
>> +	buf = kzalloc(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] = SPI_READ_FLAG;
>> +	put_unaligned_be32(*reg, buf + SPI_TRANS_PREFIX_LEN);
>> +	memset(buf + SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH, 0xff,
>> +	       SPI_READ_DUMMY_LEN);
>> +
>> +	xfers.tx_buf = buf;
>> +	xfers.rx_buf = buf;
>> +	xfers.len = SPI_READ_PREFIX_LEN + val_size;
>> +	xfers.cs_change = 0;
>> +	spi_message_add_tail(&xfers, &spi_msg);
>> +
>> +	ret = spi_sync(spi, &spi_msg);
> 
> 	error = spi_sync(...);
> 
>> +	if (ret < 0)
> 
> 	if (error)
> 
>> +		dev_err(&spi->dev, "transfer error:%d", ret);
>> +	else
>> +		memcpy(val_buf, buf + SPI_READ_PREFIX_LEN, val_size);
>> +
>> +	kfree(buf);
>> +	return ret;
>> +}
>> +
>> +static int goodix_berlin_spi_write(void *context, const void *data,
>> +				   size_t count)
>> +{
>> +	unsigned int len = count - 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 ret;
> 
> Same comments here regarding 'error' vs. 'ret'.

Seems I forgot to do the rename here, thanks for pointing it!

> 
>> +
>> +	buf = kzalloc(SPI_WRITE_PREFIX_LEN + len, GFP_KERNEL);
>> +	if (!buf)
>> +		return -ENOMEM;
>> +
>> +	spi_message_init(&spi_msg);
>> +	memset(&xfers, 0, sizeof(xfers));
>> +
>> +	buf[0] = SPI_WRITE_FLAG;
>> +	put_unaligned_be32(*reg, buf + SPI_TRANS_PREFIX_LEN);
>> +	memcpy(buf + SPI_WRITE_PREFIX_LEN, data + REGISTER_WIDTH, len);
>> +
>> +	xfers.tx_buf = buf;
>> +	xfers.len = SPI_WRITE_PREFIX_LEN + len;
>> +	xfers.cs_change = 0;
>> +	spi_message_add_tail(&xfers, &spi_msg);
>> +
>> +	ret = spi_sync(spi, &spi_msg);
>> +	if (ret < 0)
>> +		dev_err(&spi->dev, "transfer error:%d", ret);
>> +
>> +	kfree(buf);
>> +	return ret;
>> +}
>> +
>> +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;
>> +
>> +	regmap_config = devm_kmemdup(&spi->dev, &goodix_berlin_spi_regmap_conf,
>> +				     sizeof(*regmap_config), GFP_KERNEL);
>> +	if (!regmap_config)
>> +		return -ENOMEM;
> 
> Is there any reason we cannot simply pass goodix_berlin_spi_regmap_conf to
> devm_regmap_init() below? Why to duplicate and pass the copy?
> 
> For reference, BMP280 in IIO is a similar example of a device with regmap
> sitting atop a bespoke SPI protocol; it does not seem to take this extra
> step.

The goodix_berlin_spi_regmap_conf copy is modified after with the correct
max raw read/write size, and I'm not a fan of modifying a global structure
that could be use for multiple probes, I can make a copy in a stack variable
if it feels simpler.

> 
>> +
>> +	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->max_raw_read = max_size - SPI_READ_PREFIX_LEN;
>> +	regmap_config->max_raw_write = max_size - SPI_WRITE_PREFIX_LEN;
>> +
>> +	regmap = devm_regmap_init(&spi->dev, NULL, spi, regmap_config);
>> +	if (IS_ERR(regmap))
>> +		return PTR_ERR(regmap);
>> +
>> +	return goodix_berlin_probe(&spi->dev, spi->irq,
>> +				   &goodix_berlin_spi_input_id, regmap);
>> +}
>> +
>> +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
>>
> 
> Kind regards,
> Jeff LaBundy

Thanks,
Neil

Re: [PATCH v3 4/4] input: touchscreen: add SPI support for Goodix Berlin Touchscreen IC

[Jeff LaBundy]

Hi Neil,

On Mon, Jun 26, 2023 at 09:02:16AM +0200, Neil Armstrong wrote:

[...]

> > > +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;
> > > +
> > > +	regmap_config = devm_kmemdup(&spi->dev, &goodix_berlin_spi_regmap_conf,
> > > +				     sizeof(*regmap_config), GFP_KERNEL);
> > > +	if (!regmap_config)
> > > +		return -ENOMEM;
> > 
> > Is there any reason we cannot simply pass goodix_berlin_spi_regmap_conf to
> > devm_regmap_init() below? Why to duplicate and pass the copy?
> > 
> > For reference, BMP280 in IIO is a similar example of a device with regmap
> > sitting atop a bespoke SPI protocol; it does not seem to take this extra
> > step.
> 
> The goodix_berlin_spi_regmap_conf copy is modified after with the correct
> max raw read/write size, and I'm not a fan of modifying a global structure
> that could be use for multiple probes, I can make a copy in a stack variable
> if it feels simpler.

Ah, that makes sense; in that case, the existing implementation seems fine
to me. No changes necessary.

Correct me if I'm wrong, but the stack variable method wouldn't work since
that memory is gone after goodix_berlin_spi_probe() returns.

Kind regards,
Jeff LaBundy

Re: [PATCH v3 4/4] input: touchscreen: add SPI support for Goodix Berlin Touchscreen IC

[Neil Armstrong]

Hi,

On 26/06/2023 15:01, Jeff LaBundy wrote:
> Hi Neil,
> 
> On Mon, Jun 26, 2023 at 09:02:16AM +0200, Neil Armstrong wrote:
> 
> [...]
> 
>>>> +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;
>>>> +
>>>> +	regmap_config = devm_kmemdup(&spi->dev, &goodix_berlin_spi_regmap_conf,
>>>> +				     sizeof(*regmap_config), GFP_KERNEL);
>>>> +	if (!regmap_config)
>>>> +		return -ENOMEM;
>>>
>>> Is there any reason we cannot simply pass goodix_berlin_spi_regmap_conf to
>>> devm_regmap_init() below? Why to duplicate and pass the copy?
>>>
>>> For reference, BMP280 in IIO is a similar example of a device with regmap
>>> sitting atop a bespoke SPI protocol; it does not seem to take this extra
>>> step.
>>
>> The goodix_berlin_spi_regmap_conf copy is modified after with the correct
>> max raw read/write size, and I'm not a fan of modifying a global structure
>> that could be use for multiple probes, I can make a copy in a stack variable
>> if it feels simpler.
> 
> Ah, that makes sense; in that case, the existing implementation seems fine
> to me. No changes necessary.
> 
> Correct me if I'm wrong, but the stack variable method wouldn't work since
> that memory is gone after goodix_berlin_spi_probe() returns.

The config is only needed for the devm_regmap_init() duration, so keeping
the memory allocated for the whole lifetime of the device seems useless.

Neil

> 
> Kind regards,
> Jeff LaBundy

Re: [PATCH v3 4/4] input: touchscreen: add SPI support for Goodix Berlin Touchscreen IC

[Jeff LaBundy]

Hi Neil,

On Mon, Jun 26, 2023 at 03:20:35PM +0200, Neil Armstrong wrote:
> Hi,
> 
> On 26/06/2023 15:01, Jeff LaBundy wrote:
> > Hi Neil,
> > 
> > On Mon, Jun 26, 2023 at 09:02:16AM +0200, Neil Armstrong wrote:
> > 
> > [...]
> > 
> > > > > +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;
> > > > > +
> > > > > +	regmap_config = devm_kmemdup(&spi->dev, &goodix_berlin_spi_regmap_conf,
> > > > > +				     sizeof(*regmap_config), GFP_KERNEL);
> > > > > +	if (!regmap_config)
> > > > > +		return -ENOMEM;
> > > > 
> > > > Is there any reason we cannot simply pass goodix_berlin_spi_regmap_conf to
> > > > devm_regmap_init() below? Why to duplicate and pass the copy?
> > > > 
> > > > For reference, BMP280 in IIO is a similar example of a device with regmap
> > > > sitting atop a bespoke SPI protocol; it does not seem to take this extra
> > > > step.
> > > 
> > > The goodix_berlin_spi_regmap_conf copy is modified after with the correct
> > > max raw read/write size, and I'm not a fan of modifying a global structure
> > > that could be use for multiple probes, I can make a copy in a stack variable
> > > if it feels simpler.
> > 
> > Ah, that makes sense; in that case, the existing implementation seems fine
> > to me. No changes necessary.
> > 
> > Correct me if I'm wrong, but the stack variable method wouldn't work since
> > that memory is gone after goodix_berlin_spi_probe() returns.
> 
> The config is only needed for the devm_regmap_init() duration, so keeping
> the memory allocated for the whole lifetime of the device seems useless.

I revisted the regmap code, and you are indeed correct. I agree with your
suggestion.

> 
> Neil
> 
> > 
> > Kind regards,
> > Jeff LaBundy
> 

Kind regards,
Jeff LaBundy