| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20201123081940.GA9323@kozik-lap>
Date: Mon, 23 Nov 2020 09:19:40 +0100
From: "krzk@...nel.org" <krzk@...nel.org>
To: Bongsu Jeon <bongsu.jeon@...sung.com>
Cc: "kuba@...nel.org" <kuba@...nel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-nfc@...ts.01.org" <linux-nfc@...ts.01.org>,
"netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next 2/2] net: nfc: s3fwrn5: Support a UART interface
On Mon, Nov 23, 2020 at 04:56:58PM +0900, Bongsu Jeon wrote:
> 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@...sung.com>
Please start sending emails properly, e.g. with git send-email, so all
your patches in the patchset are referencing the first patch.
> ---
> 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
What about SERIAL_DEV_BUS as module? Shouldn't this be
SERIAL_DEV_BUS || !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.jeon@...sung.com>
You copied a lot from existing i2c.c. Please keep also the original
copyrights.
> + * 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"
Remove the define, it is used only once.
> +#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 */
Please do not write obvious comments. Mutex is always used to
synchronize, what else is it for? Instead you must describe what exactly
is protected with mutex.
> + 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;
> +}
All this duplicates I2C version. You need to start either reusing common
blocks.
> +
> +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 = {
const
> + .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);
You should not cast it it unsigned int. I'll fix the s3fwrn5 from which
you copied this apparently.
> + 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);
Why baudrate is fixed?
> + 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");
This is weirdly wrapped.
> + 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);
Eee.... why? Did you test this code?
> +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);
This does not look like tested...
Best regards,
Krzysztof
Powered by blists - more mailing lists