drivers/nfc/s3fwrn5/i2c.c - kernel/bruno - Git at Google

 /*
  * I2C Link Layer for Samsung S3FWRN5 NCI based Driver
  *
  * Copyright (C) 2015 Samsung Electrnoics
  * Robert Baldyga <r.baldyga@samsung.com>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2 or later, as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */

 #include <linux/i2c.h>
 #include <linux/gpio.h>
 #include <linux/delay.h>
 #include <linux/of_gpio.h>
 #include <linux/of_irq.h>
 #include <linux/module.h>

 #include <net/nfc/nfc.h>

 #include "s3fwrn5.h"

 #define S3FWRN5_I2C_DRIVER_NAME "s3fwrn5_i2c"

 #define S3FWRN5_I2C_MAX_PAYLOAD 32
 #define S3FWRN5_EN_WAIT_TIME 150

 struct s3fwrn5_i2c_phy {
 	struct i2c_client *i2c_dev;
 	struct nci_dev *ndev;

 	unsigned int gpio_en;
 	unsigned int gpio_fw_wake;

 	struct mutex mutex;

 	enum s3fwrn5_mode mode;
 	unsigned int irq_skip:1;
 };

 static void s3fwrn5_i2c_set_wake(void *phy_id, bool wake)
 {
 	struct s3fwrn5_i2c_phy *phy = phy_id;

 	mutex_lock(&phy->mutex);
 	gpio_set_value(phy->gpio_fw_wake, wake);
 	msleep(S3FWRN5_EN_WAIT_TIME/2);
 	mutex_unlock(&phy->mutex);
 }

 static void s3fwrn5_i2c_set_mode(void *phy_id, enum s3fwrn5_mode mode)
 {
 	struct s3fwrn5_i2c_phy *phy = phy_id;

 	mutex_lock(&phy->mutex);

 	if (phy->mode == mode)
 		goto out;

 	phy->mode = mode;

 	gpio_set_value(phy->gpio_en, 1);
 	gpio_set_value(phy->gpio_fw_wake, 0);
 	if (mode == S3FWRN5_MODE_FW)
 		gpio_set_value(phy->gpio_fw_wake, 1);

 	if (mode != S3FWRN5_MODE_COLD) {
 		msleep(S3FWRN5_EN_WAIT_TIME);
 		gpio_set_value(phy->gpio_en, 0);
 		msleep(S3FWRN5_EN_WAIT_TIME/2);
 	}

 	phy->irq_skip = true;

 out:
 	mutex_unlock(&phy->mutex);
 }

 static enum s3fwrn5_mode s3fwrn5_i2c_get_mode(void *phy_id)
 {
 	struct s3fwrn5_i2c_phy *phy = phy_id;
 	enum s3fwrn5_mode mode;

 	mutex_lock(&phy->mutex);

 	mode = phy->mode;

 	mutex_unlock(&phy->mutex);

 	return mode;
 }

 static int s3fwrn5_i2c_write(void *phy_id, struct sk_buff *skb)
 {
 	struct s3fwrn5_i2c_phy *phy = phy_id;
 	int ret;

 	mutex_lock(&phy->mutex);

 	phy->irq_skip = false;

 	ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
 	if (ret == -EREMOTEIO) {
 		/* Retry, chip was in standby */
 		usleep_range(110000, 120000);
 		ret  = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
 	}

 	mutex_unlock(&phy->mutex);

 	if (ret < 0)
 		return ret;

 	if (ret != skb->len)
 		return -EREMOTEIO;

 	return 0;
 }

 static struct s3fwrn5_phy_ops i2c_phy_ops = {
 	.set_wake = s3fwrn5_i2c_set_wake,
 	.set_mode = s3fwrn5_i2c_set_mode,
 	.get_mode = s3fwrn5_i2c_get_mode,
 	.write = s3fwrn5_i2c_write,
 };

 static int s3fwrn5_i2c_read(struct s3fwrn5_i2c_phy *phy)
 {
 	struct sk_buff *skb;
 	size_t hdr_size;
 	size_t data_len;
 	char hdr[4];
 	int ret;

 	hdr_size = (phy->mode == S3FWRN5_MODE_NCI) ?
 		NCI_CTRL_HDR_SIZE : S3FWRN5_FW_HDR_SIZE;
 	ret = i2c_master_recv(phy->i2c_dev, hdr, hdr_size);
 	if (ret < 0)
 		return ret;

 	if (ret < hdr_size)
 		return -EBADMSG;

 	data_len = (phy->mode == S3FWRN5_MODE_NCI) ?
 		((struct nci_ctrl_hdr *)hdr)->plen :
 		((struct s3fwrn5_fw_header *)hdr)->len;

 	skb = alloc_skb(hdr_size + data_len, GFP_KERNEL);
 	if (!skb)
 		return -ENOMEM;

 	memcpy(skb_put(skb, hdr_size), hdr, hdr_size);

 	if (data_len == 0)
 		goto out;

 	ret = i2c_master_recv(phy->i2c_dev, skb_put(skb, data_len), data_len);
 	if (ret != data_len) {
 		kfree_skb(skb);
 		return -EBADMSG;
 	}

 out:
 	return s3fwrn5_recv_frame(phy->ndev, skb, phy->mode);
 }

 static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id)
 {
 	struct s3fwrn5_i2c_phy *phy = phy_id;
 	int ret = 0;

 	if (!phy || !phy->ndev) {
 		WARN_ON_ONCE(1);
 		return IRQ_NONE;
 	}

 	mutex_lock(&phy->mutex);

 	if (phy->irq_skip)
 		goto out;

 	switch (phy->mode) {
 	case S3FWRN5_MODE_NCI:
 	case S3FWRN5_MODE_FW:
 		ret = s3fwrn5_i2c_read(phy);
 		break;
 	case S3FWRN5_MODE_COLD:
 		ret = -EREMOTEIO;
 		break;
 	}

 out:
 	mutex_unlock(&phy->mutex);

 	return IRQ_HANDLED;
 }

 static int s3fwrn5_i2c_parse_dt(struct i2c_client *client)
 {
 	struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
 	struct device_node *np = client->dev.of_node;

 	if (!np)
 		return -ENODEV;

 	phy->gpio_en = of_get_named_gpio(np, "s3fwrn5,en-gpios", 0);
 	if (!gpio_is_valid(phy->gpio_en))
 		return -ENODEV;

 	phy->gpio_fw_wake = of_get_named_gpio(np, "s3fwrn5,fw-gpios", 0);
 	if (!gpio_is_valid(phy->gpio_fw_wake))
 		return -ENODEV;

 	return 0;
 }

 static int s3fwrn5_i2c_probe(struct i2c_client *client,
 				  const struct i2c_device_id *id)
 {
 	struct s3fwrn5_i2c_phy *phy;
 	int ret;

 	phy = devm_kzalloc(&client->dev, sizeof(*phy), GFP_KERNEL);
 	if (!phy)
 		return -ENOMEM;

 	mutex_init(&phy->mutex);
 	phy->mode = S3FWRN5_MODE_COLD;
 	phy->irq_skip = true;

 	phy->i2c_dev = client;
 	i2c_set_clientdata(client, phy);

 	ret = s3fwrn5_i2c_parse_dt(client);
 	if (ret < 0)
 		return ret;

 	ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
 		GPIOF_OUT_INIT_HIGH, "s3fwrn5_en");
 	if (ret < 0)
 		return ret;

 	ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw_wake,
 		GPIOF_OUT_INIT_LOW, "s3fwrn5_fw_wake");
 	if (ret < 0)
 		return ret;

 	ret = s3fwrn5_probe(&phy->ndev, phy, &phy->i2c_dev->dev, &i2c_phy_ops,
 		S3FWRN5_I2C_MAX_PAYLOAD);
 	if (ret < 0)
 		return ret;

 	ret = devm_request_threaded_irq(&client->dev, phy->i2c_dev->irq, NULL,
 		s3fwrn5_i2c_irq_thread_fn, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
 		S3FWRN5_I2C_DRIVER_NAME, phy);
 	if (ret)
 		s3fwrn5_remove(phy->ndev);

 	return ret;
 }

 static int s3fwrn5_i2c_remove(struct i2c_client *client)
 {
 	struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);

 	s3fwrn5_remove(phy->ndev);

 	return 0;
 }

 static struct i2c_device_id s3fwrn5_i2c_id_table[] = {
 	{S3FWRN5_I2C_DRIVER_NAME, 0},
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, s3fwrn5_i2c_id_table);

 static const struct of_device_id of_s3fwrn5_i2c_match[] = {
 	{ .compatible = "samsung,s3fwrn5-i2c", },
 	{}
 };
 MODULE_DEVICE_TABLE(of, of_s3fwrn5_i2c_match);

 static struct i2c_driver s3fwrn5_i2c_driver = {
 	.driver = {
 		.owner = THIS_MODULE,
 		.name = S3FWRN5_I2C_DRIVER_NAME,
 		.of_match_table = of_match_ptr(of_s3fwrn5_i2c_match),
 	},
 	.probe = s3fwrn5_i2c_probe,
 	.remove = s3fwrn5_i2c_remove,
 	.id_table = s3fwrn5_i2c_id_table,
 };

 module_i2c_driver(s3fwrn5_i2c_driver);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("I2C driver for Samsung S3FWRN5");
 MODULE_AUTHOR("Robert Baldyga <r.baldyga@samsung.com>");
	/*
	* I2C Link Layer for Samsung S3FWRN5 NCI based Driver
	*
	* Copyright (C) 2015 Samsung Electrnoics
	* Robert Baldyga <r.baldyga@samsung.com>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2 or later, as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see <http://www.gnu.org/licenses/>.
	*/

	#include <linux/i2c.h>
	#include <linux/gpio.h>
	#include <linux/delay.h>
	#include <linux/of_gpio.h>
	#include <linux/of_irq.h>
	#include <linux/module.h>

	#include <net/nfc/nfc.h>

	#include "s3fwrn5.h"

	#define S3FWRN5_I2C_DRIVER_NAME "s3fwrn5_i2c"

	#define S3FWRN5_I2C_MAX_PAYLOAD 32
	#define S3FWRN5_EN_WAIT_TIME 150

	struct s3fwrn5_i2c_phy {
	struct i2c_client *i2c_dev;
	struct nci_dev *ndev;

	unsigned int gpio_en;
	unsigned int gpio_fw_wake;

	struct mutex mutex;

	enum s3fwrn5_mode mode;
	unsigned int irq_skip:1;
	};

	static void s3fwrn5_i2c_set_wake(void *phy_id, bool wake)
	{
	struct s3fwrn5_i2c_phy *phy = phy_id;

	mutex_lock(&phy->mutex);
	gpio_set_value(phy->gpio_fw_wake, wake);
	msleep(S3FWRN5_EN_WAIT_TIME/2);
	mutex_unlock(&phy->mutex);
	}

	static void s3fwrn5_i2c_set_mode(void *phy_id, enum s3fwrn5_mode mode)
	{
	struct s3fwrn5_i2c_phy *phy = phy_id;

	mutex_lock(&phy->mutex);

	if (phy->mode == mode)
	goto out;

	phy->mode = mode;

	gpio_set_value(phy->gpio_en, 1);
	gpio_set_value(phy->gpio_fw_wake, 0);
	if (mode == S3FWRN5_MODE_FW)
	gpio_set_value(phy->gpio_fw_wake, 1);

	if (mode != S3FWRN5_MODE_COLD) {
	msleep(S3FWRN5_EN_WAIT_TIME);
	gpio_set_value(phy->gpio_en, 0);
	msleep(S3FWRN5_EN_WAIT_TIME/2);
	}

	phy->irq_skip = true;

	out:
	mutex_unlock(&phy->mutex);
	}

	static enum s3fwrn5_mode s3fwrn5_i2c_get_mode(void *phy_id)
	{
	struct s3fwrn5_i2c_phy *phy = phy_id;
	enum s3fwrn5_mode mode;

	mutex_lock(&phy->mutex);

	mode = phy->mode;

	mutex_unlock(&phy->mutex);

	return mode;
	}

	static int s3fwrn5_i2c_write(void phy_id, struct sk_buff skb)
	{
	struct s3fwrn5_i2c_phy *phy = phy_id;
	int ret;

	mutex_lock(&phy->mutex);

	phy->irq_skip = false;

	ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
	if (ret == -EREMOTEIO) {
	/* Retry, chip was in standby */
	usleep_range(110000, 120000);
	ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
	}

	mutex_unlock(&phy->mutex);

	if (ret < 0)
	return ret;

	if (ret != skb->len)
	return -EREMOTEIO;

	return 0;
	}

	static struct s3fwrn5_phy_ops i2c_phy_ops = {
	.set_wake = s3fwrn5_i2c_set_wake,
	.set_mode = s3fwrn5_i2c_set_mode,
	.get_mode = s3fwrn5_i2c_get_mode,
	.write = s3fwrn5_i2c_write,
	};

	static int s3fwrn5_i2c_read(struct s3fwrn5_i2c_phy *phy)
	{
	struct sk_buff *skb;
	size_t hdr_size;
	size_t data_len;
	char hdr[4];
	int ret;

	hdr_size = (phy->mode == S3FWRN5_MODE_NCI) ?
	NCI_CTRL_HDR_SIZE : S3FWRN5_FW_HDR_SIZE;
	ret = i2c_master_recv(phy->i2c_dev, hdr, hdr_size);
	if (ret < 0)
	return ret;

	if (ret < hdr_size)
	return -EBADMSG;

	data_len = (phy->mode == S3FWRN5_MODE_NCI) ?
	((struct nci_ctrl_hdr *)hdr)->plen :
	((struct s3fwrn5_fw_header *)hdr)->len;

	skb = alloc_skb(hdr_size + data_len, GFP_KERNEL);
	if (!skb)
	return -ENOMEM;

	memcpy(skb_put(skb, hdr_size), hdr, hdr_size);

	if (data_len == 0)
	goto out;

	ret = i2c_master_recv(phy->i2c_dev, skb_put(skb, data_len), data_len);
	if (ret != data_len) {
	kfree_skb(skb);
	return -EBADMSG;
	}

	out:
	return s3fwrn5_recv_frame(phy->ndev, skb, phy->mode);
	}

	static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id)
	{
	struct s3fwrn5_i2c_phy *phy = phy_id;
	int ret = 0;

	if (!phy \|\| !phy->ndev) {
	WARN_ON_ONCE(1);
	return IRQ_NONE;
	}

	mutex_lock(&phy->mutex);

	if (phy->irq_skip)
	goto out;

	switch (phy->mode) {
	case S3FWRN5_MODE_NCI:
	case S3FWRN5_MODE_FW:
	ret = s3fwrn5_i2c_read(phy);
	break;
	case S3FWRN5_MODE_COLD:
	ret = -EREMOTEIO;
	break;
	}

	out:
	mutex_unlock(&phy->mutex);

	return IRQ_HANDLED;
	}

	static int s3fwrn5_i2c_parse_dt(struct i2c_client *client)
	{
	struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
	struct device_node *np = client->dev.of_node;

	if (!np)
	return -ENODEV;

	phy->gpio_en = of_get_named_gpio(np, "s3fwrn5,en-gpios", 0);
	if (!gpio_is_valid(phy->gpio_en))
	return -ENODEV;

	phy->gpio_fw_wake = of_get_named_gpio(np, "s3fwrn5,fw-gpios", 0);
	if (!gpio_is_valid(phy->gpio_fw_wake))
	return -ENODEV;

	return 0;
	}

	static int s3fwrn5_i2c_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct s3fwrn5_i2c_phy *phy;
	int ret;

	phy = devm_kzalloc(&client->dev, sizeof(*phy), GFP_KERNEL);
	if (!phy)
	return -ENOMEM;

	mutex_init(&phy->mutex);
	phy->mode = S3FWRN5_MODE_COLD;
	phy->irq_skip = true;

	phy->i2c_dev = client;
	i2c_set_clientdata(client, phy);

	ret = s3fwrn5_i2c_parse_dt(client);
	if (ret < 0)
	return ret;

	ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
	GPIOF_OUT_INIT_HIGH, "s3fwrn5_en");
	if (ret < 0)
	return ret;

	ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw_wake,
	GPIOF_OUT_INIT_LOW, "s3fwrn5_fw_wake");
	if (ret < 0)
	return ret;

	ret = s3fwrn5_probe(&phy->ndev, phy, &phy->i2c_dev->dev, &i2c_phy_ops,
	S3FWRN5_I2C_MAX_PAYLOAD);
	if (ret < 0)
	return ret;

	ret = devm_request_threaded_irq(&client->dev, phy->i2c_dev->irq, NULL,
	s3fwrn5_i2c_irq_thread_fn, IRQF_TRIGGER_HIGH \| IRQF_ONESHOT,
	S3FWRN5_I2C_DRIVER_NAME, phy);
	if (ret)
	s3fwrn5_remove(phy->ndev);

	return ret;
	}

	static int s3fwrn5_i2c_remove(struct i2c_client *client)
	{
	struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);

	s3fwrn5_remove(phy->ndev);

	return 0;
	}

	static struct i2c_device_id s3fwrn5_i2c_id_table[] = {
	{S3FWRN5_I2C_DRIVER_NAME, 0},
	{}
	};
	MODULE_DEVICE_TABLE(i2c, s3fwrn5_i2c_id_table);

	static const struct of_device_id of_s3fwrn5_i2c_match[] = {
	{ .compatible = "samsung,s3fwrn5-i2c", },
	{}
	};
	MODULE_DEVICE_TABLE(of, of_s3fwrn5_i2c_match);

	static struct i2c_driver s3fwrn5_i2c_driver = {
	.driver = {
	.owner = THIS_MODULE,
	.name = S3FWRN5_I2C_DRIVER_NAME,
	.of_match_table = of_match_ptr(of_s3fwrn5_i2c_match),
	},
	.probe = s3fwrn5_i2c_probe,
	.remove = s3fwrn5_i2c_remove,
	.id_table = s3fwrn5_i2c_id_table,
	};

	module_i2c_driver(s3fwrn5_i2c_driver);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("I2C driver for Samsung S3FWRN5");
	MODULE_AUTHOR("Robert Baldyga <r.baldyga@samsung.com>");