Since S3FWRN82 NFC Chip, The UART interface can be used.
S3FWRN82 uses NCI protocol and supports I2C and UART interface.
Signed-off-by: Bongsu Jeon <bongsu.j...@samsung.com>
---
drivers/nfc/s3fwrn5/Kconfig | 12 ++
drivers/nfc/s3fwrn5/Makefile | 2 +
drivers/nfc/s3fwrn5/uart.c | 250 +++++++++++++++++++++++++++++++++++
3 files changed, 264 insertions(+)
create mode 100644 drivers/nfc/s3fwrn5/uart.c
diff --git a/drivers/nfc/s3fwrn5/Kconfig b/drivers/nfc/s3fwrn5/Kconfig
index 3f8b6da58280..6f88737769e1 100644
--- a/drivers/nfc/s3fwrn5/Kconfig
+++ b/drivers/nfc/s3fwrn5/Kconfig
@@ -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.
diff --git a/drivers/nfc/s3fwrn5/Makefile b/drivers/nfc/s3fwrn5/Makefile
index d0ffa35f50e8..d1902102060b 100644
--- a/drivers/nfc/s3fwrn5/Makefile
+++ b/drivers/nfc/s3fwrn5/Makefile
@@ -5,6 +5,8 @@
s3fwrn5-objs = core.o firmware.o nci.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
diff --git a/drivers/nfc/s3fwrn5/uart.c b/drivers/nfc/s3fwrn5/uart.c
new file mode 100644
index 000000000000..b3c36a5b28d3
--- /dev/null
+++ b/drivers/nfc/s3fwrn5/uart.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * UART Link Layer for S3FWRN82 NCI based Driver
+ *
+ * Copyright (C) 2020 Samsung Electronics
+ * Author: Bongsu Jeon <bongsu.j...@samsung.com>
+ * All rights reserved.
+ */
+
+#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 "s3fwrn5.h"
+
+#define S3FWRN82_UART_DRIVER_NAME "s3fwrn82_uart"
+#define S3FWRN82_NCI_HEADER 3
+#define S3FWRN82_NCI_IDX 2
+#define S3FWRN82_EN_WAIT_TIME 20
+#define NCI_SKB_BUFF_LEN 258
+
+struct s3fwrn82_uart_phy {
+ struct serdev_device *ser_dev;
+ struct nci_dev *ndev;
+ struct sk_buff *recv_skb;
+
+ unsigned int gpio_en;
+ unsigned int gpio_fw_wake;
+
+ /* mutex is used to synchronize */
+ struct mutex mutex;
+ enum s3fwrn5_mode mode;
+};
+
+static void s3fwrn82_uart_set_wake(void *phy_id, bool wake)
+{
+ struct s3fwrn82_uart_phy *phy = phy_id;
+
+ mutex_lock(&phy->mutex);
+ gpio_set_value(phy->gpio_fw_wake, wake);
+ msleep(S3FWRN82_EN_WAIT_TIME);
+ mutex_unlock(&phy->mutex);
+}
+
+static void s3fwrn82_uart_set_mode(void *phy_id, enum s3fwrn5_mode mode)
+{
+ struct s3fwrn82_uart_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(S3FWRN82_EN_WAIT_TIME);
+ gpio_set_value(phy->gpio_en, 0);
+ msleep(S3FWRN82_EN_WAIT_TIME);
+ }
+out:
+ mutex_unlock(&phy->mutex);
+}
+
+static enum s3fwrn5_mode s3fwrn82_uart_get_mode(void *phy_id)
+{
+ struct s3fwrn82_uart_phy *phy = phy_id;
+ enum s3fwrn5_mode mode;
+
+ mutex_lock(&phy->mutex);
+ mode = phy->mode;
+ mutex_unlock(&phy->mutex);
+ return mode;
+}
+
+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 = s3fwrn82_uart_set_wake,
+ .set_mode = s3fwrn82_uart_set_mode,
+ .get_mode = s3fwrn82_uart_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->ndev, phy->recv_skb, phy->mode);
+ phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL);
+ if (!phy->recv_skb)
+ return 0;
+ }
+
+ return i;
+}
+
+static 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-uart", },
+ {},
+};
+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->gpio_en = of_get_named_gpio(np, "en-gpios", 0);
+ if (!gpio_is_valid(phy->gpio_en))
+ return -ENODEV;
+
+ phy->gpio_fw_wake = of_get_named_gpio(np, "wake-gpios", 0);
+ if (!gpio_is_valid(phy->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_free;
+
+ mutex_init(&phy->mutex);
+ phy->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->gpio_en,
+ GPIOF_OUT_INIT_HIGH,
+ "s3fwrn82_en");
+ if (ret < 0)
+ goto err_serdev;
+
+ ret = devm_gpio_request_one(&phy->ser_dev->dev,
+ phy->gpio_fw_wake,
+ GPIOF_OUT_INIT_LOW,
+ "s3fwrn82_fw_wake");
+ if (ret < 0)
+ goto err_serdev;
+
+ ret = s3fwrn5_probe(&phy->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_free:
+ kfree(phy);
+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->ndev);
+ serdev_device_close(serdev);
+ kfree_skb(phy->recv_skb);
+ kfree(phy);
+}
+
+static struct serdev_device_driver s3fwrn82_uart_driver = {
+ .probe = s3fwrn82_uart_probe,
+ .remove = s3fwrn82_uart_remove,
+ .driver = {
+ .name = S3FWRN82_UART_DRIVER_NAME,
+ .of_match_table = of_match_ptr(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.j...@samsung.com>");
--
2.17.1
