Merge branch 'for-6.8/mcp2200' into for-linus

- support for controlling mcp2200 GPIOs (Johannes Roith)

drivers/hid/Kconfig

@@ -1296,6 +1296,15 @@ config HID_ALPS
 	Say Y here if you have a Alps touchpads over i2c-hid or usbhid
 	and want support for its special functionalities.
 
+config HID_MCP2200
+	tristate "Microchip MCP2200 HID USB-to-GPIO bridge"
+	depends on USB_HID && GPIOLIB
+	help
+	  Provides GPIO functionality over USB-HID through MCP2200 device.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called hid-mcp2200.ko.
+
 config HID_MCP2221
 	tristate "Microchip MCP2221 HID USB-to-I2C/SMbus host support"
 	depends on USB_HID && I2C

drivers/hid/Makefile

@@ -79,6 +79,7 @@ obj-$(CONFIG_HID_LOGITECH_HIDPP)	+= hid-logitech-hidpp.o
 obj-$(CONFIG_HID_MACALLY)	+= hid-macally.o
 obj-$(CONFIG_HID_MAGICMOUSE)	+= hid-magicmouse.o
 obj-$(CONFIG_HID_MALTRON)	+= hid-maltron.o
+obj-$(CONFIG_HID_MCP2200)	+= hid-mcp2200.o
 obj-$(CONFIG_HID_MCP2221)	+= hid-mcp2221.o
 obj-$(CONFIG_HID_MAYFLASH)	+= hid-mf.o
 obj-$(CONFIG_HID_MEGAWORLD_FF)	+= hid-megaworld.o

drivers/hid/hid-ids.h

@@ -916,6 +916,7 @@
 #define USB_DEVICE_ID_PICK16F1454	0x0042
 #define USB_DEVICE_ID_PICK16F1454_V2	0xf2f7
 #define USB_DEVICE_ID_LUXAFOR		0xf372
+#define USB_DEVICE_ID_MCP2200		0x00df
 #define USB_DEVICE_ID_MCP2221		0x00dd
 
 #define USB_VENDOR_ID_MICROSOFT		0x045e

drivers/hid/hid-mcp2200.c

@@ -0,0 +1,392 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MCP2200 - Microchip USB to GPIO bridge
+ *
+ * Copyright (c) 2023, Johannes Roith <johannes@gnu-linux.rocks>
+ *
+ * Datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/22228A.pdf
+ * App Note for HID: https://ww1.microchip.com/downloads/en/DeviceDoc/93066A.pdf
+ */
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio/driver.h>
+#include <linux/hid.h>
+#include <linux/hidraw.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include "hid-ids.h"
+
+/* Commands codes in a raw output report */
+#define SET_CLEAR_OUTPUTS	0x08
+#define CONFIGURE		0x10
+#define READ_EE			0x20
+#define WRITE_EE		0x40
+#define READ_ALL		0x80
+
+/* MCP GPIO direction encoding */
+enum MCP_IO_DIR {
+	MCP2200_DIR_OUT = 0x00,
+	MCP2200_DIR_IN  = 0x01,
+};
+
+/* Altternative pin assignments */
+#define TXLED		2
+#define RXLED		3
+#define USBCFG		6
+#define SSPND		7
+#define MCP_NGPIO	8
+
+/* CMD to set or clear a GPIO output */
+struct mcp_set_clear_outputs {
+	u8 cmd;
+	u8 dummys1[10];
+	u8 set_bmap;
+	u8 clear_bmap;
+	u8 dummys2[3];
+} __packed;
+
+/* CMD to configure the IOs */
+struct mcp_configure {
+	u8 cmd;
+	u8 dummys1[3];
+	u8 io_bmap;
+	u8 config_alt_pins;
+	u8 io_default_val_bmap;
+	u8 config_alt_options;
+	u8 baud_h;
+	u8 baud_l;
+	u8 dummys2[6];
+} __packed;
+
+/* CMD to read all parameters */
+struct mcp_read_all {
+	u8 cmd;
+	u8 dummys[15];
+} __packed;
+
+/* Response to the read all cmd */
+struct mcp_read_all_resp {
+	u8 cmd;
+	u8 eep_addr;
+	u8 dummy;
+	u8 eep_val;
+	u8 io_bmap;
+	u8 config_alt_pins;
+	u8 io_default_val_bmap;
+	u8 config_alt_options;
+	u8 baud_h;
+	u8 baud_l;
+	u8 io_port_val_bmap;
+	u8 dummys[5];
+} __packed;
+
+struct mcp2200 {
+	struct hid_device *hdev;
+	struct mutex lock;
+	struct completion wait_in_report;
+	u8 gpio_dir;
+	u8 gpio_val;
+	u8 gpio_inval;
+	u8 baud_h;
+	u8 baud_l;
+	u8 config_alt_pins;
+	u8 gpio_reset_val;
+	u8 config_alt_options;
+	int status;
+	struct gpio_chip gc;
+	u8 hid_report[16];
+};
+
+/* this executes the READ_ALL cmd */
+static int mcp_cmd_read_all(struct mcp2200 *mcp)
+{
+	struct mcp_read_all *read_all;
+	int len, t;
+
+	reinit_completion(&mcp->wait_in_report);
+
+	mutex_lock(&mcp->lock);
+
+	read_all = (struct mcp_read_all *) mcp->hid_report;
+	read_all->cmd = READ_ALL;
+	len = hid_hw_output_report(mcp->hdev, (u8 *) read_all,
+				   sizeof(struct mcp_read_all));
+
+	mutex_unlock(&mcp->lock);
+
+	if (len != sizeof(struct mcp_read_all))
+		return -EINVAL;
+
+	t = wait_for_completion_timeout(&mcp->wait_in_report,
+					msecs_to_jiffies(4000));
+	if (!t)
+		return -ETIMEDOUT;
+
+	/* return status, negative value if wrong response was received */
+	return mcp->status;
+}
+
+static void mcp_set_multiple(struct gpio_chip *gc, unsigned long *mask,
+			     unsigned long *bits)
+{
+	struct mcp2200 *mcp = gpiochip_get_data(gc);
+	u8 value;
+	int status;
+	struct mcp_set_clear_outputs *cmd;
+
+	mutex_lock(&mcp->lock);
+	cmd = (struct mcp_set_clear_outputs *) mcp->hid_report;
+
+	value = mcp->gpio_val & ~*mask;
+	value |= (*mask & *bits);
+
+	cmd->cmd = SET_CLEAR_OUTPUTS;
+	cmd->set_bmap = value;
+	cmd->clear_bmap = ~(value);
+
+	status = hid_hw_output_report(mcp->hdev, (u8 *) cmd,
+		       sizeof(struct mcp_set_clear_outputs));
+
+	if (status == sizeof(struct mcp_set_clear_outputs))
+		mcp->gpio_val = value;
+
+	mutex_unlock(&mcp->lock);
+}
+
+static void mcp_set(struct gpio_chip *gc, unsigned int gpio_nr, int value)
+{
+	unsigned long mask = 1 << gpio_nr;
+	unsigned long bmap_value = value << gpio_nr;
+
+	mcp_set_multiple(gc, &mask, &bmap_value);
+}
+
+static int mcp_get_multiple(struct gpio_chip *gc, unsigned long *mask,
+		unsigned long *bits)
+{
+	u32 val;
+	struct mcp2200 *mcp = gpiochip_get_data(gc);
+	int status;
+
+	status = mcp_cmd_read_all(mcp);
+	if (status)
+		return status;
+
+	val = mcp->gpio_inval;
+	*bits = (val & *mask);
+	return 0;
+}
+
+static int mcp_get(struct gpio_chip *gc, unsigned int gpio_nr)
+{
+	unsigned long mask = 0, bits = 0;
+
+	mask = (1 << gpio_nr);
+	mcp_get_multiple(gc, &mask, &bits);
+	return bits > 0;
+}
+
+static int mcp_get_direction(struct gpio_chip *gc, unsigned int gpio_nr)
+{
+	struct mcp2200 *mcp = gpiochip_get_data(gc);
+
+	return (mcp->gpio_dir & (MCP2200_DIR_IN << gpio_nr))
+		? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT;
+}
+
+static int mcp_set_direction(struct gpio_chip *gc, unsigned int gpio_nr,
+			     enum MCP_IO_DIR io_direction)
+{
+	struct mcp2200 *mcp = gpiochip_get_data(gc);
+	struct mcp_configure *conf;
+	int status;
+	/* after the configure cmd we will need to set the outputs again */
+	unsigned long mask = ~(mcp->gpio_dir); /* only set outputs */
+	unsigned long bits = mcp->gpio_val;
+	/* Offsets of alternative pins in config_alt_pins, 0 is not used */
+	u8 alt_pin_conf[8] = {SSPND, USBCFG, 0, 0, 0, 0, RXLED, TXLED};
+	u8 config_alt_pins = mcp->config_alt_pins;
+
+	/* Read in the reset baudrate first, we need it later */
+	status = mcp_cmd_read_all(mcp);
+	if (status != 0)
+		return status;
+
+	mutex_lock(&mcp->lock);
+	conf = (struct mcp_configure  *) mcp->hid_report;
+
+	/* configure will reset the chip! */
+	conf->cmd = CONFIGURE;
+	conf->io_bmap = (mcp->gpio_dir & ~(1 << gpio_nr))
+		| (io_direction << gpio_nr);
+	/* Don't overwrite the reset parameters */
+	conf->baud_h = mcp->baud_h;
+	conf->baud_l = mcp->baud_l;
+	conf->config_alt_options = mcp->config_alt_options;
+	conf->io_default_val_bmap = mcp->gpio_reset_val;
+	/* Adjust alt. func if necessary */
+	if (alt_pin_conf[gpio_nr])
+		config_alt_pins &= ~(1 << alt_pin_conf[gpio_nr]);
+	conf->config_alt_pins = config_alt_pins;
+
+	status = hid_hw_output_report(mcp->hdev, (u8 *) conf,
+				      sizeof(struct mcp_set_clear_outputs));
+
+	if (status == sizeof(struct mcp_set_clear_outputs)) {
+		mcp->gpio_dir = conf->io_bmap;
+		mcp->config_alt_pins = config_alt_pins;
+	} else {
+		mutex_unlock(&mcp->lock);
+		return -EIO;
+	}
+
+	mutex_unlock(&mcp->lock);
+
+	/* Configure CMD will clear all IOs -> rewrite them */
+	mcp_set_multiple(gc, &mask, &bits);
+	return 0;
+}
+
+static int mcp_direction_input(struct gpio_chip *gc, unsigned int gpio_nr)
+{
+	return mcp_set_direction(gc, gpio_nr, MCP2200_DIR_IN);
+}
+
+static int mcp_direction_output(struct gpio_chip *gc, unsigned int gpio_nr,
+				int value)
+{
+	int ret;
+	unsigned long mask, bmap_value;
+
+	mask = 1 << gpio_nr;
+	bmap_value = value << gpio_nr;
+
+	ret = mcp_set_direction(gc, gpio_nr, MCP2200_DIR_OUT);
+	if (!ret)
+		mcp_set_multiple(gc, &mask, &bmap_value);
+	return ret;
+}
+
+static const struct gpio_chip template_chip = {
+	.label			= "mcp2200",
+	.owner			= THIS_MODULE,
+	.get_direction		= mcp_get_direction,
+	.direction_input	= mcp_direction_input,
+	.direction_output	= mcp_direction_output,
+	.set			= mcp_set,
+	.set_multiple		= mcp_set_multiple,
+	.get			= mcp_get,
+	.get_multiple		= mcp_get_multiple,
+	.base			= -1,
+	.ngpio			= MCP_NGPIO,
+	.can_sleep		= true,
+};
+
+/*
+ * MCP2200 uses interrupt endpoint for input reports. This function
+ * is called by HID layer when it receives i/p report from mcp2200,
+ * which is actually a response to the previously sent command.
+ */
+static int mcp2200_raw_event(struct hid_device *hdev, struct hid_report *report,
+		u8 *data, int size)
+{
+	struct mcp2200 *mcp = hid_get_drvdata(hdev);
+	struct mcp_read_all_resp *all_resp;
+
+	switch (data[0]) {
+	case READ_ALL:
+		all_resp = (struct mcp_read_all_resp *) data;
+		mcp->status = 0;
+		mcp->gpio_inval = all_resp->io_port_val_bmap;
+		mcp->baud_h = all_resp->baud_h;
+		mcp->baud_l = all_resp->baud_l;
+		mcp->gpio_reset_val = all_resp->io_default_val_bmap;
+		mcp->config_alt_pins = all_resp->config_alt_pins;
+		mcp->config_alt_options = all_resp->config_alt_options;
+		break;
+	default:
+		mcp->status = -EIO;
+		break;
+	}
+
+	complete(&mcp->wait_in_report);
+	return 0;
+}
+
+static int mcp2200_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	int ret;
+	struct mcp2200 *mcp;
+
+	mcp = devm_kzalloc(&hdev->dev, sizeof(*mcp), GFP_KERNEL);
+	if (!mcp)
+		return -ENOMEM;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "can't parse reports\n");
+		return ret;
+	}
+
+	ret = hid_hw_start(hdev, 0);
+	if (ret) {
+		hid_err(hdev, "can't start hardware\n");
+		return ret;
+	}
+
+	hid_info(hdev, "USB HID v%x.%02x Device [%s] on %s\n", hdev->version >> 8,
+			hdev->version & 0xff, hdev->name, hdev->phys);
+
+	ret = hid_hw_open(hdev);
+	if (ret) {
+		hid_err(hdev, "can't open device\n");
+		hid_hw_stop(hdev);
+		return ret;
+	}
+
+	mutex_init(&mcp->lock);
+	init_completion(&mcp->wait_in_report);
+	hid_set_drvdata(hdev, mcp);
+	mcp->hdev = hdev;
+
+	mcp->gc = template_chip;
+	mcp->gc.parent = &hdev->dev;
+
+	ret = devm_gpiochip_add_data(&hdev->dev, &mcp->gc, mcp);
+	if (ret < 0) {
+		hid_err(hdev, "Unable to register gpiochip\n");
+		hid_hw_close(hdev);
+		hid_hw_stop(hdev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void mcp2200_remove(struct hid_device *hdev)
+{
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
+static const struct hid_device_id mcp2200_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_MCP2200) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, mcp2200_devices);
+
+static struct hid_driver mcp2200_driver = {
+	.name		= "mcp2200",
+	.id_table	= mcp2200_devices,
+	.probe		= mcp2200_probe,
+	.remove		= mcp2200_remove,
+	.raw_event	= mcp2200_raw_event,
+};
+
+/* Register with HID core */
+module_hid_driver(mcp2200_driver);
+
+MODULE_AUTHOR("Johannes Roith <johannes@gnu-linux.rocks>");
+MODULE_DESCRIPTION("MCP2200 Microchip HID USB to GPIO bridge");
+MODULE_LICENSE("GPL");