[PATCH v2 net-next 4/4] net: nfc: s3fwrn5: Support a UART interface

Bongsu Jeon
2020-11-30T12:05:45Z

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From: Bongsu Jeon <bongsu.jeon@samsung.com>

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.jeon@samsung.com>
---

Changes in v2:
- remove the kfree(phy) because of duplicated free.
- use the phy_common blocks.
- wrap lines properly.

drivers/nfc/s3fwrn5/Kconfig | 12 +++
drivers/nfc/s3fwrn5/Makefile | 2 +
drivers/nfc/s3fwrn5/phy_common.c | 12 +++
drivers/nfc/s3fwrn5/phy_common.h | 1 +
drivers/nfc/s3fwrn5/uart.c | 197 +++++++++++++++++++++++++++++++++++++++
5 files changed, 224 insertions(+)
create mode 100644 drivers/nfc/s3fwrn5/uart.c

diff --git a/drivers/nfc/s3fwrn5/Kconfig b/drivers/nfc/s3fwrn5/Kconfig
index 3f8b6da..8a6b1a7 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 6b6f52d..7da827a 100644
--- a/drivers/nfc/s3fwrn5/Makefile
+++ b/drivers/nfc/s3fwrn5/Makefile
@@ -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
diff --git a/drivers/nfc/s3fwrn5/phy_common.c b/drivers/nfc/s3fwrn5/phy_common.c
index 5cad1f4..497b02b 100644
--- a/drivers/nfc/s3fwrn5/phy_common.c
+++ b/drivers/nfc/s3fwrn5/phy_common.c
@@ -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;
diff --git a/drivers/nfc/s3fwrn5/phy_common.h b/drivers/nfc/s3fwrn5/phy_common.h
index b98531d..99749c9 100644
--- a/drivers/nfc/s3fwrn5/phy_common.h
+++ b/drivers/nfc/s3fwrn5/phy_common.h
@@ -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 */
diff --git a/drivers/nfc/s3fwrn5/uart.c b/drivers/nfc/s3fwrn5/uart.c
new file mode 100644
index 0000000..f5ac017
--- /dev/null
+++ b/drivers/nfc/s3fwrn5/uart.c
@@ -0,0 +1,197 @@
+// 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_free;
+
+ 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_free:
+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 = 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.jeon@samsung.com>");
--
1.9.1