Merge branch 'nfc-s3fwrn5-support-a-uart-interface'

Bongsu Jeon says:

====================
nfc: s3fwrn5: Support a UART interface

S3FWRN82 is the Samsung's NFC chip that supports the UART communication.
Before adding the UART driver module, I did refactoring the s3fwrn5_i2c
module to reuse the common blocks.
====================

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

Documentation/devicetree/bindings/net/nfc/samsung,s3fwrn5.yaml

···
 
 properties:
   compatible:
-    const: samsung,s3fwrn5-i2c
+    enum:
+      - samsung,s3fwrn5-i2c
+      - samsung,s3fwrn82
 
   en-gpios:
     maxItems: 1
···
 required:
   - compatible
   - en-gpios
-  - interrupts
-  - reg
   - wake-gpios
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: samsung,s3fwrn5-i2c
+    then:
+      required:
+        - interrupts
+        - reg
 
 examples:
   - |
···
 
             en-gpios = <&gpf1 4 GPIO_ACTIVE_HIGH>;
             wake-gpios = <&gpj0 2 GPIO_ACTIVE_HIGH>;
+        };
+    };
+  # UART example on Raspberry Pi
+  - |
+    uart0 {
+        status = "okay";
+
+        nfc {
+            compatible = "samsung,s3fwrn82";
+
+            en-gpios = <&gpio 20 GPIO_ACTIVE_HIGH>;
+            wake-gpios = <&gpio 16 GPIO_ACTIVE_HIGH>;
+
+            status = "okay";
         };
     };

drivers/nfc/s3fwrn5/Kconfig

···
 	  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

···
 # Makefile for Samsung S3FWRN5 NFC driver
 #
 
-s3fwrn5-objs = core.o firmware.o nci.o
+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/i2c.c

···
 
 #include <net/nfc/nfc.h>
 
-#include "s3fwrn5.h"
+#include "phy_common.h"
 
 #define S3FWRN5_I2C_DRIVER_NAME "s3fwrn5_i2c"
 
-#define S3FWRN5_EN_WAIT_TIME 150
-
 struct s3fwrn5_i2c_phy {
+	struct phy_common common;
 	struct i2c_client *i2c_dev;
-	struct nci_dev *ndev;
 
-	int gpio_en;
-	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);
+	mutex_lock(&phy->common.mutex);
 
-	if (phy->mode == mode)
+	if (s3fwrn5_phy_power_ctrl(&phy->common, mode) == false)
 		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;
+	mutex_unlock(&phy->common.mutex);
 }
 
 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);
+	mutex_lock(&phy->common.mutex);
 
 	phy->irq_skip = false;
 
···
 		ret  = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
 	}
 
-	mutex_unlock(&phy->mutex);
+	mutex_unlock(&phy->common.mutex);
 
 	if (ret < 0)
 		return ret;
···
 }
 
 static const struct s3fwrn5_phy_ops i2c_phy_ops = {
-	.set_wake = s3fwrn5_i2c_set_wake,
+	.set_wake = s3fwrn5_phy_set_wake,
 	.set_mode = s3fwrn5_i2c_set_mode,
-	.get_mode = s3fwrn5_i2c_get_mode,
+	.get_mode = s3fwrn5_phy_get_mode,
 	.write = s3fwrn5_i2c_write,
 };
 
···
 	char hdr[4];
 	int ret;
 
-	hdr_size = (phy->mode == S3FWRN5_MODE_NCI) ?
+	hdr_size = (phy->common.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)
···
 	if (ret < hdr_size)
 		return -EBADMSG;
 
-	data_len = (phy->mode == S3FWRN5_MODE_NCI) ?
+	data_len = (phy->common.mode == S3FWRN5_MODE_NCI) ?
 		((struct nci_ctrl_hdr *)hdr)->plen :
 		((struct s3fwrn5_fw_header *)hdr)->len;
 
···
 	}
 
 out:
-	return s3fwrn5_recv_frame(phy->ndev, skb, phy->mode);
+	return s3fwrn5_recv_frame(phy->common.ndev, skb, phy->common.mode);
 }
 
 static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id)
 {
 	struct s3fwrn5_i2c_phy *phy = phy_id;
 
-	if (!phy || !phy->ndev) {
+	if (!phy || !phy->common.ndev) {
 		WARN_ON_ONCE(1);
 		return IRQ_NONE;
 	}
 
-	mutex_lock(&phy->mutex);
+	mutex_lock(&phy->common.mutex);
 
 	if (phy->irq_skip)
 		goto out;
 
-	switch (phy->mode) {
+	switch (phy->common.mode) {
 	case S3FWRN5_MODE_NCI:
 	case S3FWRN5_MODE_FW:
 		s3fwrn5_i2c_read(phy);
···
 	}
 
 out:
-	mutex_unlock(&phy->mutex);
+	mutex_unlock(&phy->common.mutex);
 
 	return IRQ_HANDLED;
 }
···
 	if (!np)
 		return -ENODEV;
 
-	phy->gpio_en = of_get_named_gpio(np, "en-gpios", 0);
-	if (!gpio_is_valid(phy->gpio_en)) {
+	phy->common.gpio_en = of_get_named_gpio(np, "en-gpios", 0);
+	if (!gpio_is_valid(phy->common.gpio_en)) {
 		/* Support also deprecated property */
-		phy->gpio_en = of_get_named_gpio(np, "s3fwrn5,en-gpios", 0);
-		if (!gpio_is_valid(phy->gpio_en))
+		phy->common.gpio_en = of_get_named_gpio(np,
+							"s3fwrn5,en-gpios",
+							0);
+		if (!gpio_is_valid(phy->common.gpio_en))
 			return -ENODEV;
 	}
 
-	phy->gpio_fw_wake = of_get_named_gpio(np, "wake-gpios", 0);
-	if (!gpio_is_valid(phy->gpio_fw_wake)) {
+	phy->common.gpio_fw_wake = of_get_named_gpio(np, "wake-gpios", 0);
+	if (!gpio_is_valid(phy->common.gpio_fw_wake)) {
 		/* Support also deprecated property */
-		phy->gpio_fw_wake = of_get_named_gpio(np, "s3fwrn5,fw-gpios", 0);
-		if (!gpio_is_valid(phy->gpio_fw_wake))
+		phy->common.gpio_fw_wake = of_get_named_gpio(np,
+							     "s3fwrn5,fw-gpios",
+							     0);
+		if (!gpio_is_valid(phy->common.gpio_fw_wake))
 			return -ENODEV;
 	}
 
···
 	if (!phy)
 		return -ENOMEM;
 
-	mutex_init(&phy->mutex);
-	phy->mode = S3FWRN5_MODE_COLD;
+	mutex_init(&phy->common.mutex);
+	phy->common.mode = S3FWRN5_MODE_COLD;
 	phy->irq_skip = true;
 
 	phy->i2c_dev = client;
···
 	if (ret < 0)
 		return ret;
 
-	ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
-		GPIOF_OUT_INIT_HIGH, "s3fwrn5_en");
+	ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->common.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");
+	ret = devm_gpio_request_one(&phy->i2c_dev->dev,
+				    phy->common.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);
+	ret = s3fwrn5_probe(&phy->common.ndev, phy, &phy->i2c_dev->dev,
+			    &i2c_phy_ops);
 	if (ret < 0)
 		return ret;
 
···
 		s3fwrn5_i2c_irq_thread_fn, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
 		S3FWRN5_I2C_DRIVER_NAME, phy);
 	if (ret)
-		s3fwrn5_remove(phy->ndev);
+		s3fwrn5_remove(phy->common.ndev);
 
 	return ret;
 }
···
 {
 	struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
 
-	s3fwrn5_remove(phy->ndev);
+	s3fwrn5_remove(phy->common.ndev);
 
 	return 0;
 }

drivers/nfc/s3fwrn5/phy_common.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Link Layer for Samsung S3FWRN5 NCI based Driver
+ *
+ * Copyright (C) 2015 Samsung Electrnoics
+ * Robert Baldyga <[e-mail]>
+ * Copyright (C) 2020 Samsung Electrnoics
+ * Bongsu Jeon <[e-mail]>
+ */
+
+#include <linux/gpio.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+
+#include "phy_common.h"
+
+void s3fwrn5_phy_set_wake(void *phy_id, bool wake)
+{
+	struct phy_common *phy = phy_id;
+
+	mutex_lock(&phy->mutex);
+	gpio_set_value(phy->gpio_fw_wake, wake);
+	msleep(S3FWRN5_EN_WAIT_TIME);
+	mutex_unlock(&phy->mutex);
+}
+EXPORT_SYMBOL(s3fwrn5_phy_set_wake);
+
+bool s3fwrn5_phy_power_ctrl(struct phy_common *phy, enum s3fwrn5_mode mode)
+{
+	if (phy->mode == mode)
+		return false;
+
+	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);
+	}
+
+	return true;
+}
+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;
+	enum s3fwrn5_mode mode;
+
+	mutex_lock(&phy->mutex);
+
+	mode = phy->mode;
+
+	mutex_unlock(&phy->mutex);
+
+	return mode;
+}
+EXPORT_SYMBOL(s3fwrn5_phy_get_mode);

drivers/nfc/s3fwrn5/phy_common.h

···
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * Link Layer for Samsung S3FWRN5 NCI based Driver
+ *
+ * Copyright (C) 2015 Samsung Electrnoics
+ * Robert Baldyga <[e-mail]>
+ * Copyright (C) 2020 Samsung Electrnoics
+ * Bongsu Jeon <[e-mail]>
+ */
+
+#ifndef __NFC_S3FWRN5_PHY_COMMON_H
+#define __NFC_S3FWRN5_PHY_COMMON_H
+
+#include <linux/mutex.h>
+#include <net/nfc/nci_core.h>
+
+#include "s3fwrn5.h"
+
+#define S3FWRN5_EN_WAIT_TIME 20
+
+struct phy_common {
+	struct nci_dev *ndev;
+
+	int gpio_en;
+	int gpio_fw_wake;
+
+	struct mutex mutex;
+
+	enum s3fwrn5_mode mode;
+};
+
+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

···
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * UART Link Layer for S3FWRN82 NCI based Driver
+ *
+ * Copyright (C) 2015 Samsung Electronics
+ * Robert Baldyga <[e-mail]>
+ * Copyright (C) 2020 Samsung Electronics
+ * Bongsu Jeon <[e-mail]>
+ */
+
+#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 <[e-mail]>");