drivers/gpio/gpio-viperboard.c - kernel/msm-4.9 - Gitiles

 /*
  *  Nano River Technologies viperboard GPIO lib driver
  *
  *  (C) 2012 by Lemonage GmbH
  *  Author: Lars Poeschel <poeschel@lemonage.de>
  *  All rights reserved.
  *
  *  This program is free software; you can redistribute  it and/or modify it
  *  under  the terms of  the GNU General  Public License as published by the
  *  Free Software Foundation;  either version 2 of the	License, or (at your
  *  option) any later version.
  *
  */

 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/mutex.h>
 #include <linux/platform_device.h>

 #include <linux/usb.h>
 #include <linux/gpio.h>

 #include <linux/mfd/viperboard.h>

 #define VPRBRD_GPIOA_CLK_1MHZ		0
 #define VPRBRD_GPIOA_CLK_100KHZ		1
 #define VPRBRD_GPIOA_CLK_10KHZ		2
 #define VPRBRD_GPIOA_CLK_1KHZ		3
 #define VPRBRD_GPIOA_CLK_100HZ		4
 #define VPRBRD_GPIOA_CLK_10HZ		5

 #define VPRBRD_GPIOA_FREQ_DEFAULT	1000

 #define VPRBRD_GPIOA_CMD_CONT		0x00
 #define VPRBRD_GPIOA_CMD_PULSE		0x01
 #define VPRBRD_GPIOA_CMD_PWM		0x02
 #define VPRBRD_GPIOA_CMD_SETOUT		0x03
 #define VPRBRD_GPIOA_CMD_SETIN		0x04
 #define VPRBRD_GPIOA_CMD_SETINT		0x05
 #define VPRBRD_GPIOA_CMD_GETIN		0x06

 #define VPRBRD_GPIOB_CMD_SETDIR		0x00
 #define VPRBRD_GPIOB_CMD_SETVAL		0x01

 struct vprbrd_gpioa_msg {
 	u8 cmd;
 	u8 clk;
 	u8 offset;
 	u8 t1;
 	u8 t2;
 	u8 invert;
 	u8 pwmlevel;
 	u8 outval;
 	u8 risefall;
 	u8 answer;
 	u8 __fill;
 } __packed;

 struct vprbrd_gpiob_msg {
 	u8 cmd;
 	u16 val;
 	u16 mask;
 } __packed;

 struct vprbrd_gpio {
 	struct gpio_chip gpioa; /* gpio a related things */
 	u32 gpioa_out;
 	u32 gpioa_val;
 	struct gpio_chip gpiob; /* gpio b related things */
 	u32 gpiob_out;
 	u32 gpiob_val;
 	struct vprbrd *vb;
 };

 /* gpioa sampling clock module parameter */
 static unsigned char gpioa_clk;
 static unsigned int gpioa_freq = VPRBRD_GPIOA_FREQ_DEFAULT;
 module_param(gpioa_freq, uint, 0);
 MODULE_PARM_DESC(gpioa_freq,
 	"gpio-a sampling freq in Hz (default is 1000Hz) valid values: 10, 100, 1000, 10000, 100000, 1000000");

 /* ----- begin of gipo a chip -------------------------------------------- */

 static int vprbrd_gpioa_get(struct gpio_chip *chip,
 		unsigned offset)
 {
 	int ret, answer, error = 0;
 	struct vprbrd_gpio *gpio =
 			container_of(chip, struct vprbrd_gpio, gpioa);
 	struct vprbrd *vb = gpio->vb;
 	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;

 	/* if io is set to output, just return the saved value */
 	if (gpio->gpioa_out & (1 << offset))
 		return gpio->gpioa_val & (1 << offset);

 	mutex_lock(&vb->lock);

 	gamsg->cmd = VPRBRD_GPIOA_CMD_GETIN;
 	gamsg->clk = 0x00;
 	gamsg->offset = offset;
 	gamsg->t1 = 0x00;
 	gamsg->t2 = 0x00;
 	gamsg->invert = 0x00;
 	gamsg->pwmlevel = 0x00;
 	gamsg->outval = 0x00;
 	gamsg->risefall = 0x00;
 	gamsg->answer = 0x00;
 	gamsg->__fill = 0x00;

 	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
 		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
 		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
 		VPRBRD_USB_TIMEOUT_MS);
 	if (ret != sizeof(struct vprbrd_gpioa_msg))
 		error = -EREMOTEIO;

 	ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
 		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_IN, 0x0000,
 		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
 		VPRBRD_USB_TIMEOUT_MS);
 	answer = gamsg->answer & 0x01;

 	mutex_unlock(&vb->lock);

 	if (ret != sizeof(struct vprbrd_gpioa_msg))
 		error = -EREMOTEIO;

 	if (error)
 		return error;

 	return answer;
 }

 static void vprbrd_gpioa_set(struct gpio_chip *chip,
 		unsigned offset, int value)
 {
 	int ret;
 	struct vprbrd_gpio *gpio =
 			container_of(chip, struct vprbrd_gpio, gpioa);
 	struct vprbrd *vb = gpio->vb;
 	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;

 	if (gpio->gpioa_out & (1 << offset)) {
 		if (value)
 			gpio->gpioa_val |= (1 << offset);
 		else
 			gpio->gpioa_val &= ~(1 << offset);

 		mutex_lock(&vb->lock);

 		gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
 		gamsg->clk = 0x00;
 		gamsg->offset = offset;
 		gamsg->t1 = 0x00;
 		gamsg->t2 = 0x00;
 		gamsg->invert = 0x00;
 		gamsg->pwmlevel = 0x00;
 		gamsg->outval = value;
 		gamsg->risefall = 0x00;
 		gamsg->answer = 0x00;
 		gamsg->__fill = 0x00;

 		ret = usb_control_msg(vb->usb_dev,
 			usb_sndctrlpipe(vb->usb_dev, 0),
 			VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT,
 			0x0000,	0x0000, gamsg,
 			sizeof(struct vprbrd_gpioa_msg), VPRBRD_USB_TIMEOUT_MS);

 		mutex_unlock(&vb->lock);

 		if (ret != sizeof(struct vprbrd_gpioa_msg))
 			dev_err(chip->dev, "usb error setting pin value\n");
 	}
 }

 static int vprbrd_gpioa_direction_input(struct gpio_chip *chip,
 			unsigned offset)
 {
 	int ret;
 	struct vprbrd_gpio *gpio =
 			container_of(chip, struct vprbrd_gpio, gpioa);
 	struct vprbrd *vb = gpio->vb;
 	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;

 	gpio->gpioa_out &= ~(1 << offset);

 	mutex_lock(&vb->lock);

 	gamsg->cmd = VPRBRD_GPIOA_CMD_SETIN;
 	gamsg->clk = gpioa_clk;
 	gamsg->offset = offset;
 	gamsg->t1 = 0x00;
 	gamsg->t2 = 0x00;
 	gamsg->invert = 0x00;
 	gamsg->pwmlevel = 0x00;
 	gamsg->outval = 0x00;
 	gamsg->risefall = 0x00;
 	gamsg->answer = 0x00;
 	gamsg->__fill = 0x00;

 	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
 		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
 		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
 		VPRBRD_USB_TIMEOUT_MS);

 	mutex_unlock(&vb->lock);

 	if (ret != sizeof(struct vprbrd_gpioa_msg))
 		return -EREMOTEIO;

 	return 0;
 }

 static int vprbrd_gpioa_direction_output(struct gpio_chip *chip,
 			unsigned offset, int value)
 {
 	int ret;
 	struct vprbrd_gpio *gpio =
 			container_of(chip, struct vprbrd_gpio, gpioa);
 	struct vprbrd *vb = gpio->vb;
 	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;

 	gpio->gpioa_out |= (1 << offset);
 	if (value)
 		gpio->gpioa_val |= (1 << offset);
 	else
 		gpio->gpioa_val &= ~(1 << offset);

 	mutex_lock(&vb->lock);

 	gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
 	gamsg->clk = 0x00;
 	gamsg->offset = offset;
 	gamsg->t1 = 0x00;
 	gamsg->t2 = 0x00;
 	gamsg->invert = 0x00;
 	gamsg->pwmlevel = 0x00;
 	gamsg->outval = value;
 	gamsg->risefall = 0x00;
 	gamsg->answer = 0x00;
 	gamsg->__fill = 0x00;

 	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
 		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
 		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
 		VPRBRD_USB_TIMEOUT_MS);

 	mutex_unlock(&vb->lock);

 	if (ret != sizeof(struct vprbrd_gpioa_msg))
 		return -EREMOTEIO;

 	return 0;
 }

 /* ----- end of gpio a chip ---------------------------------------------- */

 /* ----- begin of gipo b chip -------------------------------------------- */

 static int vprbrd_gpiob_setdir(struct vprbrd *vb, unsigned offset,
 	unsigned dir)
 {
 	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
 	int ret;

 	gbmsg->cmd = VPRBRD_GPIOB_CMD_SETDIR;
 	gbmsg->val = cpu_to_be16(dir << offset);
 	gbmsg->mask = cpu_to_be16(0x0001 << offset);

 	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
 		VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT, 0x0000,
 		0x0000, gbmsg, sizeof(struct vprbrd_gpiob_msg),
 		VPRBRD_USB_TIMEOUT_MS);

 	if (ret != sizeof(struct vprbrd_gpiob_msg))
 		return -EREMOTEIO;

 	return 0;
 }

 static int vprbrd_gpiob_get(struct gpio_chip *chip,
 		unsigned offset)
 {
 	int ret;
 	u16 val;
 	struct vprbrd_gpio *gpio =
 			container_of(chip, struct vprbrd_gpio, gpiob);
 	struct vprbrd *vb = gpio->vb;
 	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;

 	/* if io is set to output, just return the saved value */
 	if (gpio->gpiob_out & (1 << offset))
 		return gpio->gpiob_val & (1 << offset);

 	mutex_lock(&vb->lock);

 	ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
 		VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_IN, 0x0000,
 		0x0000, gbmsg,	sizeof(struct vprbrd_gpiob_msg),
 		VPRBRD_USB_TIMEOUT_MS);
 	val = gbmsg->val;

 	mutex_unlock(&vb->lock);

 	if (ret != sizeof(struct vprbrd_gpiob_msg))
 		return ret;

 	/* cache the read values */
 	gpio->gpiob_val = be16_to_cpu(val);

 	return (gpio->gpiob_val >> offset) & 0x1;
 }

 static void vprbrd_gpiob_set(struct gpio_chip *chip,
 		unsigned offset, int value)
 {
 	int ret;
 	struct vprbrd_gpio *gpio =
 			container_of(chip, struct vprbrd_gpio, gpiob);
 	struct vprbrd *vb = gpio->vb;
 	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;

 	if (gpio->gpiob_out & (1 << offset)) {
 		if (value)
 			gpio->gpiob_val |= (1 << offset);
 		else
 			gpio->gpiob_val &= ~(1 << offset);

 		mutex_lock(&vb->lock);

 		gbmsg->cmd = VPRBRD_GPIOB_CMD_SETVAL;
 		gbmsg->val = cpu_to_be16(value << offset);
 		gbmsg->mask = cpu_to_be16(0x0001 << offset);

 		ret = usb_control_msg(vb->usb_dev,
 			usb_sndctrlpipe(vb->usb_dev, 0),
 			VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT,
 			0x0000,	0x0000, gbmsg,
 			sizeof(struct vprbrd_gpiob_msg), VPRBRD_USB_TIMEOUT_MS);

 		mutex_unlock(&vb->lock);

 		if (ret != sizeof(struct vprbrd_gpiob_msg))
 			dev_err(chip->dev, "usb error setting pin value\n");
 	}
 }

 static int vprbrd_gpiob_direction_input(struct gpio_chip *chip,
 			unsigned offset)
 {
 	int ret;
 	struct vprbrd_gpio *gpio =
 			container_of(chip, struct vprbrd_gpio, gpiob);
 	struct vprbrd *vb = gpio->vb;

 	gpio->gpiob_out &= ~(1 << offset);

 	mutex_lock(&vb->lock);

 	ret = vprbrd_gpiob_setdir(vb, offset, 0);

 	mutex_unlock(&vb->lock);

 	if (ret)
 		dev_err(chip->dev, "usb error setting pin to input\n");

 	return ret;
 }

 static int vprbrd_gpiob_direction_output(struct gpio_chip *chip,
 			unsigned offset, int value)
 {
 	int ret;
 	struct vprbrd_gpio *gpio =
 			container_of(chip, struct vprbrd_gpio, gpiob);
 	struct vprbrd *vb = gpio->vb;

 	gpio->gpiob_out |= (1 << offset);
 	if (value)
 		gpio->gpiob_val |= (1 << offset);
 	else
 		gpio->gpiob_val &= ~(1 << offset);

 	mutex_lock(&vb->lock);

 	ret = vprbrd_gpiob_setdir(vb, offset, 1);
 	if (ret)
 		dev_err(chip->dev, "usb error setting pin to output\n");

 	mutex_unlock(&vb->lock);

 	vprbrd_gpiob_set(chip, offset, value);

 	return ret;
 }

 /* ----- end of gpio b chip ---------------------------------------------- */

 static int vprbrd_gpio_probe(struct platform_device *pdev)
 {
 	struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
 	struct vprbrd_gpio *vb_gpio;
 	int ret;

 	vb_gpio = devm_kzalloc(&pdev->dev, sizeof(*vb_gpio), GFP_KERNEL);
 	if (vb_gpio == NULL)
 		return -ENOMEM;

 	vb_gpio->vb = vb;
 	/* registering gpio a */
 	vb_gpio->gpioa.label = "viperboard gpio a";
 	vb_gpio->gpioa.dev = &pdev->dev;
 	vb_gpio->gpioa.owner = THIS_MODULE;
 	vb_gpio->gpioa.base = -1;
 	vb_gpio->gpioa.ngpio = 16;
 	vb_gpio->gpioa.can_sleep = 1;
 	vb_gpio->gpioa.set = vprbrd_gpioa_set;
 	vb_gpio->gpioa.get = vprbrd_gpioa_get;
 	vb_gpio->gpioa.direction_input = vprbrd_gpioa_direction_input;
 	vb_gpio->gpioa.direction_output = vprbrd_gpioa_direction_output;
 	ret = gpiochip_add(&vb_gpio->gpioa);
 	if (ret < 0) {
 		dev_err(vb_gpio->gpioa.dev, "could not add gpio a");
 		goto err_gpioa;
 	}

 	/* registering gpio b */
 	vb_gpio->gpiob.label = "viperboard gpio b";
 	vb_gpio->gpiob.dev = &pdev->dev;
 	vb_gpio->gpiob.owner = THIS_MODULE;
 	vb_gpio->gpiob.base = -1;
 	vb_gpio->gpiob.ngpio = 16;
 	vb_gpio->gpiob.can_sleep = 1;
 	vb_gpio->gpiob.set = vprbrd_gpiob_set;
 	vb_gpio->gpiob.get = vprbrd_gpiob_get;
 	vb_gpio->gpiob.direction_input = vprbrd_gpiob_direction_input;
 	vb_gpio->gpiob.direction_output = vprbrd_gpiob_direction_output;
 	ret = gpiochip_add(&vb_gpio->gpiob);
 	if (ret < 0) {
 		dev_err(vb_gpio->gpiob.dev, "could not add gpio b");
 		goto err_gpiob;
 	}

 	platform_set_drvdata(pdev, vb_gpio);

 	return ret;

 err_gpiob:
 	ret = gpiochip_remove(&vb_gpio->gpioa);

 err_gpioa:
 	return ret;
 }

 static int vprbrd_gpio_remove(struct platform_device *pdev)
 {
 	struct vprbrd_gpio *vb_gpio = platform_get_drvdata(pdev);
 	int ret;

 	ret = gpiochip_remove(&vb_gpio->gpiob);
 	if (ret == 0)
 		ret = gpiochip_remove(&vb_gpio->gpioa);

 	return ret;
 }

 static struct platform_driver vprbrd_gpio_driver = {
 	.driver.name	= "viperboard-gpio",
 	.driver.owner	= THIS_MODULE,
 	.probe		= vprbrd_gpio_probe,
 	.remove		= vprbrd_gpio_remove,
 };

 static int __init vprbrd_gpio_init(void)
 {
 	switch (gpioa_freq) {
 	case 1000000:
 		gpioa_clk = VPRBRD_GPIOA_CLK_1MHZ;
 		break;
 	case 100000:
 		gpioa_clk = VPRBRD_GPIOA_CLK_100KHZ;
 		break;
 	case 10000:
 		gpioa_clk = VPRBRD_GPIOA_CLK_10KHZ;
 		break;
 	case 1000:
 		gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
 		break;
 	case 100:
 		gpioa_clk = VPRBRD_GPIOA_CLK_100HZ;
 		break;
 	case 10:
 		gpioa_clk = VPRBRD_GPIOA_CLK_10HZ;
 		break;
 	default:
 		pr_warn("invalid gpioa_freq (%d)\n", gpioa_freq);
 		gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
 	}

 	return platform_driver_register(&vprbrd_gpio_driver);
 }
 subsys_initcall(vprbrd_gpio_init);

 static void __exit vprbrd_gpio_exit(void)
 {
 	platform_driver_unregister(&vprbrd_gpio_driver);
 }
 module_exit(vprbrd_gpio_exit);

 MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
 MODULE_DESCRIPTION("GPIO driver for Nano River Techs Viperboard");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:viperboard-gpio");
	/*
	* Nano River Technologies viperboard GPIO lib driver
	*
	* (C) 2012 by Lemonage GmbH
	* Author: Lars Poeschel <poeschel@lemonage.de>
	* All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the
	* Free Software Foundation; either version 2 of the License, or (at your
	* option) any later version.
	*
	*/

	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/types.h>
	#include <linux/mutex.h>
	#include <linux/platform_device.h>

	#include <linux/usb.h>
	#include <linux/gpio.h>

	#include <linux/mfd/viperboard.h>

	#define VPRBRD_GPIOA_CLK_1MHZ 0
	#define VPRBRD_GPIOA_CLK_100KHZ 1
	#define VPRBRD_GPIOA_CLK_10KHZ 2
	#define VPRBRD_GPIOA_CLK_1KHZ 3
	#define VPRBRD_GPIOA_CLK_100HZ 4
	#define VPRBRD_GPIOA_CLK_10HZ 5

	#define VPRBRD_GPIOA_FREQ_DEFAULT 1000

	#define VPRBRD_GPIOA_CMD_CONT 0x00
	#define VPRBRD_GPIOA_CMD_PULSE 0x01
	#define VPRBRD_GPIOA_CMD_PWM 0x02
	#define VPRBRD_GPIOA_CMD_SETOUT 0x03
	#define VPRBRD_GPIOA_CMD_SETIN 0x04
	#define VPRBRD_GPIOA_CMD_SETINT 0x05
	#define VPRBRD_GPIOA_CMD_GETIN 0x06

	#define VPRBRD_GPIOB_CMD_SETDIR 0x00
	#define VPRBRD_GPIOB_CMD_SETVAL 0x01

	struct vprbrd_gpioa_msg {
	u8 cmd;
	u8 clk;
	u8 offset;
	u8 t1;
	u8 t2;
	u8 invert;
	u8 pwmlevel;
	u8 outval;
	u8 risefall;
	u8 answer;
	u8 __fill;
	} __packed;

	struct vprbrd_gpiob_msg {
	u8 cmd;
	u16 val;
	u16 mask;
	} __packed;

	struct vprbrd_gpio {
	struct gpio_chip gpioa; /* gpio a related things */
	u32 gpioa_out;
	u32 gpioa_val;
	struct gpio_chip gpiob; /* gpio b related things */
	u32 gpiob_out;
	u32 gpiob_val;
	struct vprbrd *vb;
	};

	/* gpioa sampling clock module parameter */
	static unsigned char gpioa_clk;
	static unsigned int gpioa_freq = VPRBRD_GPIOA_FREQ_DEFAULT;
	module_param(gpioa_freq, uint, 0);
	MODULE_PARM_DESC(gpioa_freq,
	"gpio-a sampling freq in Hz (default is 1000Hz) valid values: 10, 100, 1000, 10000, 100000, 1000000");

	/* ----- begin of gipo a chip -------------------------------------------- */

	static int vprbrd_gpioa_get(struct gpio_chip *chip,
	unsigned offset)
	{
	int ret, answer, error = 0;
	struct vprbrd_gpio *gpio =
	container_of(chip, struct vprbrd_gpio, gpioa);
	struct vprbrd *vb = gpio->vb;
	struct vprbrd_gpioa_msg gamsg = (struct vprbrd_gpioa_msg )vb->buf;

	/* if io is set to output, just return the saved value */
	if (gpio->gpioa_out & (1 << offset))
	return gpio->gpioa_val & (1 << offset);

	mutex_lock(&vb->lock);

	gamsg->cmd = VPRBRD_GPIOA_CMD_GETIN;
	gamsg->clk = 0x00;
	gamsg->offset = offset;
	gamsg->t1 = 0x00;
	gamsg->t2 = 0x00;
	gamsg->invert = 0x00;
	gamsg->pwmlevel = 0x00;
	gamsg->outval = 0x00;
	gamsg->risefall = 0x00;
	gamsg->answer = 0x00;
	gamsg->__fill = 0x00;

	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
	VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
	0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
	VPRBRD_USB_TIMEOUT_MS);
	if (ret != sizeof(struct vprbrd_gpioa_msg))
	error = -EREMOTEIO;

	ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
	VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_IN, 0x0000,
	0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
	VPRBRD_USB_TIMEOUT_MS);
	answer = gamsg->answer & 0x01;

	mutex_unlock(&vb->lock);

	if (ret != sizeof(struct vprbrd_gpioa_msg))
	error = -EREMOTEIO;

	if (error)
	return error;

	return answer;
	}

	static void vprbrd_gpioa_set(struct gpio_chip *chip,
	unsigned offset, int value)
	{
	int ret;
	struct vprbrd_gpio *gpio =
	container_of(chip, struct vprbrd_gpio, gpioa);
	struct vprbrd *vb = gpio->vb;
	struct vprbrd_gpioa_msg gamsg = (struct vprbrd_gpioa_msg )vb->buf;

	if (gpio->gpioa_out & (1 << offset)) {
	if (value)
	gpio->gpioa_val \|= (1 << offset);
	else
	gpio->gpioa_val &= ~(1 << offset);

	mutex_lock(&vb->lock);

	gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
	gamsg->clk = 0x00;
	gamsg->offset = offset;
	gamsg->t1 = 0x00;
	gamsg->t2 = 0x00;
	gamsg->invert = 0x00;
	gamsg->pwmlevel = 0x00;
	gamsg->outval = value;
	gamsg->risefall = 0x00;
	gamsg->answer = 0x00;
	gamsg->__fill = 0x00;

	ret = usb_control_msg(vb->usb_dev,
	usb_sndctrlpipe(vb->usb_dev, 0),
	VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT,
	0x0000, 0x0000, gamsg,
	sizeof(struct vprbrd_gpioa_msg), VPRBRD_USB_TIMEOUT_MS);

	mutex_unlock(&vb->lock);

	if (ret != sizeof(struct vprbrd_gpioa_msg))
	dev_err(chip->dev, "usb error setting pin value\n");
	}
	}

	static int vprbrd_gpioa_direction_input(struct gpio_chip *chip,
	unsigned offset)
	{
	int ret;
	struct vprbrd_gpio *gpio =
	container_of(chip, struct vprbrd_gpio, gpioa);
	struct vprbrd *vb = gpio->vb;
	struct vprbrd_gpioa_msg gamsg = (struct vprbrd_gpioa_msg )vb->buf;

	gpio->gpioa_out &= ~(1 << offset);

	mutex_lock(&vb->lock);

	gamsg->cmd = VPRBRD_GPIOA_CMD_SETIN;
	gamsg->clk = gpioa_clk;
	gamsg->offset = offset;
	gamsg->t1 = 0x00;
	gamsg->t2 = 0x00;
	gamsg->invert = 0x00;
	gamsg->pwmlevel = 0x00;
	gamsg->outval = 0x00;
	gamsg->risefall = 0x00;
	gamsg->answer = 0x00;
	gamsg->__fill = 0x00;

	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
	VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
	0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
	VPRBRD_USB_TIMEOUT_MS);

	mutex_unlock(&vb->lock);

	if (ret != sizeof(struct vprbrd_gpioa_msg))
	return -EREMOTEIO;

	return 0;
	}

	static int vprbrd_gpioa_direction_output(struct gpio_chip *chip,
	unsigned offset, int value)
	{
	int ret;
	struct vprbrd_gpio *gpio =
	container_of(chip, struct vprbrd_gpio, gpioa);
	struct vprbrd *vb = gpio->vb;
	struct vprbrd_gpioa_msg gamsg = (struct vprbrd_gpioa_msg )vb->buf;

	gpio->gpioa_out \|= (1 << offset);
	if (value)
	gpio->gpioa_val \|= (1 << offset);
	else
	gpio->gpioa_val &= ~(1 << offset);

	mutex_lock(&vb->lock);

	gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
	gamsg->clk = 0x00;
	gamsg->offset = offset;
	gamsg->t1 = 0x00;
	gamsg->t2 = 0x00;
	gamsg->invert = 0x00;
	gamsg->pwmlevel = 0x00;
	gamsg->outval = value;
	gamsg->risefall = 0x00;
	gamsg->answer = 0x00;
	gamsg->__fill = 0x00;

	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
	VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
	0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
	VPRBRD_USB_TIMEOUT_MS);

	mutex_unlock(&vb->lock);

	if (ret != sizeof(struct vprbrd_gpioa_msg))
	return -EREMOTEIO;

	return 0;
	}

	/* ----- end of gpio a chip ---------------------------------------------- */

	/* ----- begin of gipo b chip -------------------------------------------- */

	static int vprbrd_gpiob_setdir(struct vprbrd *vb, unsigned offset,
	unsigned dir)
	{
	struct vprbrd_gpiob_msg gbmsg = (struct vprbrd_gpiob_msg )vb->buf;
	int ret;

	gbmsg->cmd = VPRBRD_GPIOB_CMD_SETDIR;
	gbmsg->val = cpu_to_be16(dir << offset);
	gbmsg->mask = cpu_to_be16(0x0001 << offset);

	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
	VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT, 0x0000,
	0x0000, gbmsg, sizeof(struct vprbrd_gpiob_msg),
	VPRBRD_USB_TIMEOUT_MS);

	if (ret != sizeof(struct vprbrd_gpiob_msg))
	return -EREMOTEIO;

	return 0;
	}

	static int vprbrd_gpiob_get(struct gpio_chip *chip,
	unsigned offset)
	{
	int ret;
	u16 val;
	struct vprbrd_gpio *gpio =
	container_of(chip, struct vprbrd_gpio, gpiob);
	struct vprbrd *vb = gpio->vb;
	struct vprbrd_gpiob_msg gbmsg = (struct vprbrd_gpiob_msg )vb->buf;

	/* if io is set to output, just return the saved value */
	if (gpio->gpiob_out & (1 << offset))
	return gpio->gpiob_val & (1 << offset);

	mutex_lock(&vb->lock);

	ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
	VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_IN, 0x0000,
	0x0000, gbmsg, sizeof(struct vprbrd_gpiob_msg),
	VPRBRD_USB_TIMEOUT_MS);
	val = gbmsg->val;

	mutex_unlock(&vb->lock);

	if (ret != sizeof(struct vprbrd_gpiob_msg))
	return ret;

	/* cache the read values */
	gpio->gpiob_val = be16_to_cpu(val);

	return (gpio->gpiob_val >> offset) & 0x1;
	}

	static void vprbrd_gpiob_set(struct gpio_chip *chip,
	unsigned offset, int value)
	{
	int ret;
	struct vprbrd_gpio *gpio =
	container_of(chip, struct vprbrd_gpio, gpiob);
	struct vprbrd *vb = gpio->vb;
	struct vprbrd_gpiob_msg gbmsg = (struct vprbrd_gpiob_msg )vb->buf;

	if (gpio->gpiob_out & (1 << offset)) {
	if (value)
	gpio->gpiob_val \|= (1 << offset);
	else
	gpio->gpiob_val &= ~(1 << offset);

	mutex_lock(&vb->lock);

	gbmsg->cmd = VPRBRD_GPIOB_CMD_SETVAL;
	gbmsg->val = cpu_to_be16(value << offset);
	gbmsg->mask = cpu_to_be16(0x0001 << offset);

	ret = usb_control_msg(vb->usb_dev,
	usb_sndctrlpipe(vb->usb_dev, 0),
	VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT,
	0x0000, 0x0000, gbmsg,
	sizeof(struct vprbrd_gpiob_msg), VPRBRD_USB_TIMEOUT_MS);

	mutex_unlock(&vb->lock);

	if (ret != sizeof(struct vprbrd_gpiob_msg))
	dev_err(chip->dev, "usb error setting pin value\n");
	}
	}

	static int vprbrd_gpiob_direction_input(struct gpio_chip *chip,
	unsigned offset)
	{
	int ret;
	struct vprbrd_gpio *gpio =
	container_of(chip, struct vprbrd_gpio, gpiob);
	struct vprbrd *vb = gpio->vb;

	gpio->gpiob_out &= ~(1 << offset);

	mutex_lock(&vb->lock);

	ret = vprbrd_gpiob_setdir(vb, offset, 0);

	mutex_unlock(&vb->lock);

	if (ret)
	dev_err(chip->dev, "usb error setting pin to input\n");

	return ret;
	}

	static int vprbrd_gpiob_direction_output(struct gpio_chip *chip,
	unsigned offset, int value)
	{
	int ret;
	struct vprbrd_gpio *gpio =
	container_of(chip, struct vprbrd_gpio, gpiob);
	struct vprbrd *vb = gpio->vb;

	gpio->gpiob_out \|= (1 << offset);
	if (value)
	gpio->gpiob_val \|= (1 << offset);
	else
	gpio->gpiob_val &= ~(1 << offset);

	mutex_lock(&vb->lock);

	ret = vprbrd_gpiob_setdir(vb, offset, 1);
	if (ret)
	dev_err(chip->dev, "usb error setting pin to output\n");

	mutex_unlock(&vb->lock);

	vprbrd_gpiob_set(chip, offset, value);

	return ret;
	}

	/* ----- end of gpio b chip ---------------------------------------------- */

	static int vprbrd_gpio_probe(struct platform_device *pdev)
	{
	struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
	struct vprbrd_gpio *vb_gpio;
	int ret;

	vb_gpio = devm_kzalloc(&pdev->dev, sizeof(*vb_gpio), GFP_KERNEL);
	if (vb_gpio == NULL)
	return -ENOMEM;

	vb_gpio->vb = vb;
	/* registering gpio a */
	vb_gpio->gpioa.label = "viperboard gpio a";
	vb_gpio->gpioa.dev = &pdev->dev;
	vb_gpio->gpioa.owner = THIS_MODULE;
	vb_gpio->gpioa.base = -1;
	vb_gpio->gpioa.ngpio = 16;
	vb_gpio->gpioa.can_sleep = 1;
	vb_gpio->gpioa.set = vprbrd_gpioa_set;
	vb_gpio->gpioa.get = vprbrd_gpioa_get;
	vb_gpio->gpioa.direction_input = vprbrd_gpioa_direction_input;
	vb_gpio->gpioa.direction_output = vprbrd_gpioa_direction_output;
	ret = gpiochip_add(&vb_gpio->gpioa);
	if (ret < 0) {
	dev_err(vb_gpio->gpioa.dev, "could not add gpio a");
	goto err_gpioa;
	}

	/* registering gpio b */
	vb_gpio->gpiob.label = "viperboard gpio b";
	vb_gpio->gpiob.dev = &pdev->dev;
	vb_gpio->gpiob.owner = THIS_MODULE;
	vb_gpio->gpiob.base = -1;
	vb_gpio->gpiob.ngpio = 16;
	vb_gpio->gpiob.can_sleep = 1;
	vb_gpio->gpiob.set = vprbrd_gpiob_set;
	vb_gpio->gpiob.get = vprbrd_gpiob_get;
	vb_gpio->gpiob.direction_input = vprbrd_gpiob_direction_input;
	vb_gpio->gpiob.direction_output = vprbrd_gpiob_direction_output;
	ret = gpiochip_add(&vb_gpio->gpiob);
	if (ret < 0) {
	dev_err(vb_gpio->gpiob.dev, "could not add gpio b");
	goto err_gpiob;
	}

	platform_set_drvdata(pdev, vb_gpio);

	return ret;

	err_gpiob:
	ret = gpiochip_remove(&vb_gpio->gpioa);

	err_gpioa:
	return ret;
	}

	static int vprbrd_gpio_remove(struct platform_device *pdev)
	{
	struct vprbrd_gpio *vb_gpio = platform_get_drvdata(pdev);
	int ret;

	ret = gpiochip_remove(&vb_gpio->gpiob);
	if (ret == 0)
	ret = gpiochip_remove(&vb_gpio->gpioa);

	return ret;
	}

	static struct platform_driver vprbrd_gpio_driver = {
	.driver.name = "viperboard-gpio",
	.driver.owner = THIS_MODULE,
	.probe = vprbrd_gpio_probe,
	.remove = vprbrd_gpio_remove,
	};

	static int __init vprbrd_gpio_init(void)
	{
	switch (gpioa_freq) {
	case 1000000:
	gpioa_clk = VPRBRD_GPIOA_CLK_1MHZ;
	break;
	case 100000:
	gpioa_clk = VPRBRD_GPIOA_CLK_100KHZ;
	break;
	case 10000:
	gpioa_clk = VPRBRD_GPIOA_CLK_10KHZ;
	break;
	case 1000:
	gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
	break;
	case 100:
	gpioa_clk = VPRBRD_GPIOA_CLK_100HZ;
	break;
	case 10:
	gpioa_clk = VPRBRD_GPIOA_CLK_10HZ;
	break;
	default:
	pr_warn("invalid gpioa_freq (%d)\n", gpioa_freq);
	gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
	}

	return platform_driver_register(&vprbrd_gpio_driver);
	}
	subsys_initcall(vprbrd_gpio_init);

	static void __exit vprbrd_gpio_exit(void)
	{
	platform_driver_unregister(&vprbrd_gpio_driver);
	}
	module_exit(vprbrd_gpio_exit);

	MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
	MODULE_DESCRIPTION("GPIO driver for Nano River Techs Viperboard");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:viperboard-gpio");