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

Krzysztof Kozlowski
2020-11-30T18:45:55Z

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On Mon, Nov 30, 2020 at 09:05:45PM +0900, Bongsu Jeon wrote:
> 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),

Compile with W=1. Fix the warnings - preferably by removing
of_match_ptr().

Best regards,
Krzysztof