Input: synaptics-rmi4 - add support for F3A

RMI4 F3A supports the touchpad GPIO function, it's designed to
support more GPIOs and used on newer touchpads. This patch adds
support of the touchpad buttons.

Signed-off-by: Vincent Huang <vincent.huang@tw.synaptics.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andrew Duggan <aduggan@synaptics.com>
Link: https://lore.kernel.org/r/20200930094147.635556-3-vincent.huang@tw.synaptics.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/rmi4/Kconfig

@@ -100,6 +100,14 @@ config RMI4_F34
 	  device via the firmware loader interface. This is triggered using a
 	  sysfs attribute.
 
+config RMI4_F3A
+	bool "RMI4 Function 3A (GPIO)"
+	help
+	  Say Y here if you want to add support for RMI4 function 3A.
+
+	  Function 3A provides GPIO support for RMI4 devices. This includes
+	  support for buttons on TouchPads and ClickPads.
+
 config RMI4_F54
 	bool "RMI4 Function 54 (Analog diagnostics)"
 	depends on VIDEO_V4L2=y || (RMI4_CORE=m && VIDEO_V4L2=m)

drivers/input/rmi4/Makefile

@@ -10,6 +10,7 @@ rmi_core-$(CONFIG_RMI4_F11) += rmi_f11.o
 rmi_core-$(CONFIG_RMI4_F12) += rmi_f12.o
 rmi_core-$(CONFIG_RMI4_F30) += rmi_f30.o
 rmi_core-$(CONFIG_RMI4_F34) += rmi_f34.o rmi_f34v7.o
+rmi_core-$(CONFIG_RMI4_F3A) += rmi_f3a.o
 rmi_core-$(CONFIG_RMI4_F54) += rmi_f54.o
 rmi_core-$(CONFIG_RMI4_F55) += rmi_f55.o
 

drivers/input/rmi4/rmi_bus.c

@@ -365,6 +365,9 @@ static struct rmi_function_handler *fn_handlers[] = {
 #ifdef CONFIG_RMI4_F34
 	&rmi_f34_handler,
 #endif
+#ifdef CONFIG_RMI4_F3A
+	&rmi_f3a_handler,
+#endif
 #ifdef CONFIG_RMI4_F54
 	&rmi_f54_handler,
 #endif

drivers/input/rmi4/rmi_driver.h

@@ -135,6 +135,7 @@ extern struct rmi_function_handler rmi_f11_handler;
 extern struct rmi_function_handler rmi_f12_handler;
 extern struct rmi_function_handler rmi_f30_handler;
 extern struct rmi_function_handler rmi_f34_handler;
+extern struct rmi_function_handler rmi_f3a_handler;
 extern struct rmi_function_handler rmi_f54_handler;
 extern struct rmi_function_handler rmi_f55_handler;
 #endif

drivers/input/rmi4/rmi_f3a.c

@@ -0,0 +1,241 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2012-2020 Synaptics Incorporated
+ */
+
+#include <linux/kernel.h>
+#include <linux/rmi.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include "rmi_driver.h"
+
+#define RMI_F3A_MAX_GPIO_COUNT		128
+#define RMI_F3A_MAX_REG_SIZE		DIV_ROUND_UP(RMI_F3A_MAX_GPIO_COUNT, 8)
+
+/* Defs for Query 0 */
+#define RMI_F3A_GPIO_COUNT		0x7F
+
+#define RMI_F3A_DATA_REGS_MAX_SIZE	RMI_F3A_MAX_REG_SIZE
+
+#define TRACKSTICK_RANGE_START		3
+#define TRACKSTICK_RANGE_END		6
+
+struct f3a_data {
+	/* Query Data */
+	u8 gpio_count;
+
+	u8 register_count;
+
+	u8 data_regs[RMI_F3A_DATA_REGS_MAX_SIZE];
+	u16 *gpio_key_map;
+
+	struct input_dev *input;
+
+	struct rmi_function *f03;
+	bool trackstick_buttons;
+};
+
+static void rmi_f3a_report_button(struct rmi_function *fn,
+				  struct f3a_data *f3a, unsigned int button)
+{
+	u16 key_code = f3a->gpio_key_map[button];
+	bool key_down = !(f3a->data_regs[0] & BIT(button));
+
+	if (f3a->trackstick_buttons &&
+		button >= TRACKSTICK_RANGE_START &&
+		button <= TRACKSTICK_RANGE_END) {
+		rmi_f03_overwrite_button(f3a->f03, key_code, key_down);
+	} else {
+		rmi_dbg(RMI_DEBUG_FN, &fn->dev,
+			"%s: call input report key (0x%04x) value (0x%02x)",
+			__func__, key_code, key_down);
+		input_report_key(f3a->input, key_code, key_down);
+	}
+}
+
+static irqreturn_t rmi_f3a_attention(int irq, void *ctx)
+{
+	struct rmi_function *fn = ctx;
+	struct f3a_data *f3a = dev_get_drvdata(&fn->dev);
+	struct rmi_driver_data *drvdata = dev_get_drvdata(&fn->rmi_dev->dev);
+	int error;
+	int i;
+
+	if (drvdata->attn_data.data) {
+		if (drvdata->attn_data.size < f3a->register_count) {
+			dev_warn(&fn->dev,
+				 "F3A interrupted, but data is missing\n");
+			return IRQ_HANDLED;
+		}
+		memcpy(f3a->data_regs, drvdata->attn_data.data,
+			f3a->register_count);
+		drvdata->attn_data.data += f3a->register_count;
+		drvdata->attn_data.size -= f3a->register_count;
+	} else {
+		error = rmi_read_block(fn->rmi_dev, fn->fd.data_base_addr,
+					f3a->data_regs, f3a->register_count);
+		if (error) {
+			dev_err(&fn->dev,
+				"%s: Failed to read F3a data registers: %d\n",
+				__func__, error);
+			return IRQ_RETVAL(error);
+		}
+	}
+
+	for (i = 0; i < f3a->gpio_count; i++)
+		if (f3a->gpio_key_map[i] != KEY_RESERVED)
+			rmi_f3a_report_button(fn, f3a, i);
+	if (f3a->trackstick_buttons)
+		rmi_f03_commit_buttons(f3a->f03);
+
+	return IRQ_HANDLED;
+}
+
+static int rmi_f3a_config(struct rmi_function *fn)
+{
+	struct f3a_data *f3a = dev_get_drvdata(&fn->dev);
+	struct rmi_driver *drv = fn->rmi_dev->driver;
+	const struct rmi_device_platform_data *pdata =
+			rmi_get_platform_data(fn->rmi_dev);
+
+	if (!f3a)
+		return 0;
+
+	if (pdata->gpio_data.trackstick_buttons) {
+		/* Try [re-]establish link to F03. */
+		f3a->f03 = rmi_find_function(fn->rmi_dev, 0x03);
+		f3a->trackstick_buttons = f3a->f03 != NULL;
+	}
+
+	drv->set_irq_bits(fn->rmi_dev, fn->irq_mask);
+
+	return 0;
+}
+
+static bool rmi_f3a_is_valid_button(int button, struct f3a_data *f3a,
+					u8 *query1_regs, u8 *ctrl1_regs)
+{
+	/* gpio exist && direction input */
+	return (query1_regs[0] & BIT(button)) && !(ctrl1_regs[0] & BIT(button));
+}
+
+static int rmi_f3a_map_gpios(struct rmi_function *fn, struct f3a_data *f3a,
+				u8 *query1_regs, u8 *ctrl1_regs)
+{
+	const struct rmi_device_platform_data *pdata =
+			rmi_get_platform_data(fn->rmi_dev);
+	struct input_dev *input = f3a->input;
+	unsigned int button = BTN_LEFT;
+	unsigned int trackstick_button = BTN_LEFT;
+	bool button_mapped = false;
+	int i;
+	int button_count = min_t(u8, f3a->gpio_count, TRACKSTICK_RANGE_END);
+
+	f3a->gpio_key_map = devm_kcalloc(&fn->dev,
+						button_count,
+						sizeof(f3a->gpio_key_map[0]),
+						GFP_KERNEL);
+	if (!f3a->gpio_key_map) {
+		dev_err(&fn->dev, "Failed to allocate gpio map memory.\n");
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < button_count; i++) {
+		if (!rmi_f3a_is_valid_button(i, f3a, query1_regs, ctrl1_regs))
+			continue;
+
+		if (pdata->gpio_data.trackstick_buttons &&
+			i >= TRACKSTICK_RANGE_START &&
+			i < TRACKSTICK_RANGE_END) {
+			f3a->gpio_key_map[i] = trackstick_button++;
+		} else if (!pdata->gpio_data.buttonpad || !button_mapped) {
+			f3a->gpio_key_map[i] = button;
+			input_set_capability(input, EV_KEY, button++);
+			button_mapped = true;
+		}
+	}
+	input->keycode = f3a->gpio_key_map;
+	input->keycodesize = sizeof(f3a->gpio_key_map[0]);
+	input->keycodemax = f3a->gpio_count;
+
+	if (pdata->gpio_data.buttonpad || (button - BTN_LEFT == 1))
+		__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
+
+	return 0;
+}
+
+static int rmi_f3a_initialize(struct rmi_function *fn, struct f3a_data *f3a)
+{
+	u8 query1[RMI_F3A_MAX_REG_SIZE];
+	u8 ctrl1[RMI_F3A_MAX_REG_SIZE];
+	u8 buf;
+	int error;
+
+	error = rmi_read(fn->rmi_dev, fn->fd.query_base_addr, &buf);
+	if (error < 0) {
+		dev_err(&fn->dev, "Failed to read general info register: %d\n",
+			error);
+		return -ENODEV;
+	}
+
+	f3a->gpio_count = buf & RMI_F3A_GPIO_COUNT;
+	f3a->register_count = DIV_ROUND_UP(f3a->gpio_count, 8);
+
+	/* Query1 -> gpio exist */
+	error = rmi_read_block(fn->rmi_dev, fn->fd.query_base_addr + 1,
+				query1, f3a->register_count);
+	if (error) {
+		dev_err(&fn->dev, "Failed to read query1 register\n");
+		return error;
+	}
+
+	/* Ctrl1 -> gpio direction */
+	error = rmi_read_block(fn->rmi_dev, fn->fd.control_base_addr + 1,
+				ctrl1, f3a->register_count);
+	if (error) {
+		dev_err(&fn->dev, "Failed to read control1 register\n");
+		return error;
+	}
+
+	error = rmi_f3a_map_gpios(fn, f3a, query1, ctrl1);
+	if (error)
+		return error;
+
+	return 0;
+}
+
+static int rmi_f3a_probe(struct rmi_function *fn)
+{
+	struct rmi_device *rmi_dev = fn->rmi_dev;
+	struct rmi_driver_data *drv_data = dev_get_drvdata(&rmi_dev->dev);
+	struct f3a_data *f3a;
+	int error;
+
+	if (!drv_data->input) {
+		dev_info(&fn->dev, "F3A: no input device found, ignoring\n");
+		return -ENXIO;
+	}
+
+	f3a = devm_kzalloc(&fn->dev, sizeof(*f3a), GFP_KERNEL);
+	if (!f3a)
+		return -ENOMEM;
+
+	f3a->input = drv_data->input;
+
+	error = rmi_f3a_initialize(fn, f3a);
+	if (error)
+		return error;
+
+	dev_set_drvdata(&fn->dev, f3a);
+	return 0;
+}
+
+struct rmi_function_handler rmi_f3a_handler = {
+	.driver = {
+		.name = "rmi4_f3a",
+	},
+	.func = 0x3a,
+	.probe = rmi_f3a_probe,
+	.config = rmi_f3a_config,
+	.attention = rmi_f3a_attention,
+};