Commit 3f52c2cb authored by Bongsu Jeon's avatar Bongsu Jeon Committed by Jakub Kicinski
Browse files

nfc: s3fwrn5: Support a UART interface 



Since S3FWRN82 NFC Chip, The UART interface can be used.
S3FWRN82 uses NCI protocol and supports I2C and UART interface.

Reviewed-by: default avatarKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: default avatarBongsu Jeon <bongsu.jeon@samsung.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b3799d59

drivers/nfc/s3fwrn5/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -20,3 +20,15 @@ config NFC_S3FWRN5_I2C 
	  To compile this driver as a module, choose m here. The module will

	  be called s3fwrn5_i2c.ko.

	  Say N if unsure.



config NFC_S3FWRN82_UART

        tristate "Samsung S3FWRN82 UART support"

        depends on NFC_NCI && SERIAL_DEV_BUS

        select NFC_S3FWRN5

        help

          This module adds support for a UART interface to the S3FWRN82 chip.

          Select this if your platform is using the UART bus.



          To compile this driver as a module, choose m here. The module will

          be called s3fwrn82_uart.ko.

          Say N if unsure.

drivers/nfc/s3fwrn5/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -5,6 +5,8 @@ 


s3fwrn5-objs = core.o firmware.o nci.o phy_common.o

s3fwrn5_i2c-objs = i2c.o

s3fwrn82_uart-objs = uart.o



obj-$(CONFIG_NFC_S3FWRN5) += s3fwrn5.o

obj-$(CONFIG_NFC_S3FWRN5_I2C) += s3fwrn5_i2c.o

obj-$(CONFIG_NFC_S3FWRN82_UART) += s3fwrn82_uart.o

drivers/nfc/s3fwrn5/phy_common.c

+12 −0
Original line number Diff line number Diff line
@@ -47,6 +47,18 @@ bool s3fwrn5_phy_power_ctrl(struct phy_common *phy, enum s3fwrn5_mode mode) 
}

EXPORT_SYMBOL(s3fwrn5_phy_power_ctrl);



void s3fwrn5_phy_set_mode(void *phy_id, enum s3fwrn5_mode mode)

{

	struct phy_common *phy = phy_id;



	mutex_lock(&phy->mutex);



	s3fwrn5_phy_power_ctrl(phy, mode);



	mutex_unlock(&phy->mutex);

}

EXPORT_SYMBOL(s3fwrn5_phy_set_mode);



enum s3fwrn5_mode s3fwrn5_phy_get_mode(void *phy_id)

{

	struct phy_common *phy = phy_id;

drivers/nfc/s3fwrn5/phy_common.h

+1 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ struct phy_common { 


void s3fwrn5_phy_set_wake(void *phy_id, bool wake);

bool s3fwrn5_phy_power_ctrl(struct phy_common *phy, enum s3fwrn5_mode mode);

void s3fwrn5_phy_set_mode(void *phy_id, enum s3fwrn5_mode mode);

enum s3fwrn5_mode s3fwrn5_phy_get_mode(void *phy_id);



#endif /* __NFC_S3FWRN5_PHY_COMMON_H */

drivers/nfc/s3fwrn5/uart.c

0 → 100644
+196 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+

/*

 * UART Link Layer for S3FWRN82 NCI based Driver

 *

 * Copyright (C) 2015 Samsung Electronics

 * Robert Baldyga <r.baldyga@samsung.com>

 * Copyright (C) 2020 Samsung Electronics

 * Bongsu Jeon <bongsu.jeon@samsung.com>

 */



#include <linux/device.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/nfc.h>

#include <linux/netdevice.h>

#include <linux/of.h>

#include <linux/serdev.h>

#include <linux/gpio.h>

#include <linux/of_gpio.h>



#include "phy_common.h"



#define S3FWRN82_NCI_HEADER 3

#define S3FWRN82_NCI_IDX 2

#define NCI_SKB_BUFF_LEN 258



struct s3fwrn82_uart_phy {

	struct phy_common common;

	struct serdev_device *ser_dev;

	struct sk_buff *recv_skb;

};



static int s3fwrn82_uart_write(void *phy_id, struct sk_buff *out)

{

	struct s3fwrn82_uart_phy *phy = phy_id;

	int err;



	err = serdev_device_write(phy->ser_dev,

				  out->data, out->len,

				  MAX_SCHEDULE_TIMEOUT);

	if (err < 0)

		return err;



	return 0;

}



static const struct s3fwrn5_phy_ops uart_phy_ops = {

	.set_wake = s3fwrn5_phy_set_wake,

	.set_mode = s3fwrn5_phy_set_mode,

	.get_mode = s3fwrn5_phy_get_mode,

	.write = s3fwrn82_uart_write,

};



static int s3fwrn82_uart_read(struct serdev_device *serdev,

			      const unsigned char *data,

			      size_t count)

{

	struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev);

	size_t i;



	for (i = 0; i < count; i++) {

		skb_put_u8(phy->recv_skb, *data++);



		if (phy->recv_skb->len < S3FWRN82_NCI_HEADER)

			continue;



		if ((phy->recv_skb->len - S3FWRN82_NCI_HEADER)

				< phy->recv_skb->data[S3FWRN82_NCI_IDX])

			continue;



		s3fwrn5_recv_frame(phy->common.ndev, phy->recv_skb,

				   phy->common.mode);

		phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL);

		if (!phy->recv_skb)

			return 0;

	}



	return i;

}



static const struct serdev_device_ops s3fwrn82_serdev_ops = {

	.receive_buf = s3fwrn82_uart_read,

	.write_wakeup = serdev_device_write_wakeup,

};



static const struct of_device_id s3fwrn82_uart_of_match[] = {

	{ .compatible = "samsung,s3fwrn82", },

	{},

};

MODULE_DEVICE_TABLE(of, s3fwrn82_uart_of_match);



static int s3fwrn82_uart_parse_dt(struct serdev_device *serdev)

{

	struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev);

	struct device_node *np = serdev->dev.of_node;



	if (!np)

		return -ENODEV;



	phy->common.gpio_en = of_get_named_gpio(np, "en-gpios", 0);

	if (!gpio_is_valid(phy->common.gpio_en))

		return -ENODEV;



	phy->common.gpio_fw_wake = of_get_named_gpio(np, "wake-gpios", 0);

	if (!gpio_is_valid(phy->common.gpio_fw_wake))

		return -ENODEV;



	return 0;

}



static int s3fwrn82_uart_probe(struct serdev_device *serdev)

{

	struct s3fwrn82_uart_phy *phy;

	int ret = -ENOMEM;



	phy = devm_kzalloc(&serdev->dev, sizeof(*phy), GFP_KERNEL);

	if (!phy)

		goto err_exit;



	phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL);

	if (!phy->recv_skb)

		goto err_exit;



	mutex_init(&phy->common.mutex);

	phy->common.mode = S3FWRN5_MODE_COLD;



	phy->ser_dev = serdev;

	serdev_device_set_drvdata(serdev, phy);

	serdev_device_set_client_ops(serdev, &s3fwrn82_serdev_ops);

	ret = serdev_device_open(serdev);

	if (ret) {

		dev_err(&serdev->dev, "Unable to open device\n");

		goto err_skb;

	}



	ret = serdev_device_set_baudrate(serdev, 115200);

	if (ret != 115200) {

		ret = -EINVAL;

		goto err_serdev;

	}



	serdev_device_set_flow_control(serdev, false);



	ret = s3fwrn82_uart_parse_dt(serdev);

	if (ret < 0)

		goto err_serdev;



	ret = devm_gpio_request_one(&phy->ser_dev->dev, phy->common.gpio_en,

				    GPIOF_OUT_INIT_HIGH, "s3fwrn82_en");

	if (ret < 0)

		goto err_serdev;



	ret = devm_gpio_request_one(&phy->ser_dev->dev,

				    phy->common.gpio_fw_wake,

				    GPIOF_OUT_INIT_LOW, "s3fwrn82_fw_wake");

	if (ret < 0)

		goto err_serdev;



	ret = s3fwrn5_probe(&phy->common.ndev, phy, &phy->ser_dev->dev,

			    &uart_phy_ops);

	if (ret < 0)

		goto err_serdev;



	return ret;



err_serdev:

	serdev_device_close(serdev);

err_skb:

	kfree_skb(phy->recv_skb);

err_exit:

	return ret;

}



static void s3fwrn82_uart_remove(struct serdev_device *serdev)

{

	struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev);



	s3fwrn5_remove(phy->common.ndev);

	serdev_device_close(serdev);

	kfree_skb(phy->recv_skb);

}



static struct serdev_device_driver s3fwrn82_uart_driver = {

	.probe = s3fwrn82_uart_probe,

	.remove = s3fwrn82_uart_remove,

	.driver = {

		.name = "s3fwrn82_uart",

		.of_match_table = s3fwrn82_uart_of_match,

	},

};



module_serdev_device_driver(s3fwrn82_uart_driver);



MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("UART driver for Samsung NFC");

MODULE_AUTHOR("Bongsu Jeon <bongsu.jeon@samsung.com>");