From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Lukas Wunner <lukas@wunner.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>,
"Matwey V. Kornilov" <matwey@sai.msu.ru>,
Giulio Benetti <giulio.benetti@micronovasrl.com>,
Heiko Stuebner <heiko@sntech.de>,
Christoph Muellner <christoph.muellner@theobroma-systems.com>,
linux-serial@vger.kernel.org
Subject: Re: [PATCH v2 2/4] serial: Allow uart_get_rs485_mode() to return errno
Date: Tue, 12 May 2020 16:46:52 +0300 [thread overview]
Message-ID: <20200512134652.GA185537@smile.fi.intel.com> (raw)
In-Reply-To: <271e814af4b0db3bffbbb74abf2b46b75add4516.1589285873.git.lukas@wunner.de>
On Tue, May 12, 2020 at 02:40:02PM +0200, Lukas Wunner wrote:
> We're about to amend uart_get_rs485_mode() to support a GPIO pin for
> rs485 bus termination. Retrieving the GPIO descriptor may fail, so
> allow uart_get_rs485_mode() to return an errno and change all callers
> to check for failure.
>
> The GPIO descriptor is going to be stored in struct uart_port. Pass
> that struct to uart_get_rs485_mode() in lieu of a struct device and
> struct serial_rs485, both of which are directly accessible from struct
> uart_port.
>
> A few drivers call uart_get_rs485_mode() before setting the struct
> device pointer in struct uart_port. Shuffle those calls around where
> necessary.
> [Heiko Stuebner did the ar933x_uart.c portion, hence his Signed-off-by.]
We also have Co-developed-by tag in addition to SoB to specify the credit.
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> Signed-off-by: Lukas Wunner <lukas@wunner.de>
> ---
> drivers/tty/serial/8250/8250_core.c | 4 +++-
> drivers/tty/serial/ar933x_uart.c | 6 ++++--
> drivers/tty/serial/atmel_serial.c | 6 ++++--
> drivers/tty/serial/fsl_lpuart.c | 5 ++++-
> drivers/tty/serial/imx.c | 6 +++++-
> drivers/tty/serial/omap-serial.c | 4 +++-
> drivers/tty/serial/serial_core.c | 6 +++++-
> drivers/tty/serial/stm32-usart.c | 8 ++++----
> include/linux/serial_core.h | 2 +-
> 9 files changed, 33 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
> index 9548d3f8fc8e..fc118f649887 100644
> --- a/drivers/tty/serial/8250/8250_core.c
> +++ b/drivers/tty/serial/8250/8250_core.c
> @@ -1026,7 +1026,9 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
>
> if (up->port.dev) {
> uart->port.dev = up->port.dev;
> - uart_get_rs485_mode(uart->port.dev, &uart->port.rs485);
> + ret = uart_get_rs485_mode(&uart->port);
> + if (ret)
> + goto err;
> }
>
> if (up->port.flags & UPF_FIXED_TYPE)
> diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c
> index 7e7f1398019f..0c80a79d7442 100644
> --- a/drivers/tty/serial/ar933x_uart.c
> +++ b/drivers/tty/serial/ar933x_uart.c
> @@ -766,8 +766,6 @@ static int ar933x_uart_probe(struct platform_device *pdev)
> goto err_disable_clk;
> }
>
> - uart_get_rs485_mode(&pdev->dev, &port->rs485);
> -
> port->mapbase = mem_res->start;
> port->line = id;
> port->irq = irq_res->start;
> @@ -786,6 +784,10 @@ static int ar933x_uart_probe(struct platform_device *pdev)
> baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP);
> up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD);
>
> + ret = uart_get_rs485_mode(port);
> + if (ret)
> + goto err_disable_clk;
> +
> up->gpios = mctrl_gpio_init(port, 0);
> if (IS_ERR(up->gpios) && PTR_ERR(up->gpios) != -ENOSYS)
> return PTR_ERR(up->gpios);
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 8d7080efad9b..e43471b33710 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -2491,8 +2491,6 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
> atmel_init_property(atmel_port, pdev);
> atmel_set_ops(port);
>
> - uart_get_rs485_mode(&mpdev->dev, &port->rs485);
> -
> port->iotype = UPIO_MEM;
> port->flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
> port->ops = &atmel_pops;
> @@ -2506,6 +2504,10 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
>
> memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
>
> + ret = uart_get_rs485_mode(port);
> + if (ret)
> + return ret;
> +
> /* for console, the clock could already be configured */
> if (!atmel_port->clk) {
> atmel_port->clk = clk_get(&mpdev->dev, "usart");
> diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
> index 6a9909e56449..029324c77cd7 100644
> --- a/drivers/tty/serial/fsl_lpuart.c
> +++ b/drivers/tty/serial/fsl_lpuart.c
> @@ -2619,7 +2619,9 @@ static int lpuart_probe(struct platform_device *pdev)
> if (ret)
> goto failed_attach_port;
>
> - uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
> + ret = uart_get_rs485_mode(&sport->port);
> + if (ret)
> + goto failed_get_rs485;
>
> if (sport->port.rs485.flags & SER_RS485_RX_DURING_TX)
> dev_err(&pdev->dev, "driver doesn't support RX during TX\n");
> @@ -2632,6 +2634,7 @@ static int lpuart_probe(struct platform_device *pdev)
>
> return 0;
>
> +failed_get_rs485:
> failed_attach_port:
> failed_irq_request:
> lpuart_disable_clks(sport);
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index f4d68109bc8b..91f3910d6c44 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -2302,7 +2302,11 @@ static int imx_uart_probe(struct platform_device *pdev)
> sport->ucr4 = readl(sport->port.membase + UCR4);
> sport->ufcr = readl(sport->port.membase + UFCR);
>
> - uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
> + ret = uart_get_rs485_mode(&sport->port);
> + if (ret) {
> + clk_disable_unprepare(sport->clk_ipg);
> + return ret;
> + }
>
> if (sport->port.rs485.flags & SER_RS485_ENABLED &&
> (!sport->have_rtscts && !sport->have_rtsgpio))
> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
> index c71c1a2266dc..8573fc9cb0cd 100644
> --- a/drivers/tty/serial/omap-serial.c
> +++ b/drivers/tty/serial/omap-serial.c
> @@ -1608,7 +1608,9 @@ static int serial_omap_probe_rs485(struct uart_omap_port *up,
> if (!np)
> return 0;
>
> - uart_get_rs485_mode(up->dev, rs485conf);
> + ret = uart_get_rs485_mode(&up->port);
> + if (ret)
> + return ret;
>
> if (of_property_read_bool(np, "rs485-rts-active-high")) {
> rs485conf->flags |= SER_RS485_RTS_ON_SEND;
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index 66a5e2faf57e..43b6682877d5 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -3295,8 +3295,10 @@ EXPORT_SYMBOL(uart_remove_one_port);
> * This function implements the device tree binding described in
> * Documentation/devicetree/bindings/serial/rs485.txt.
> */
> -void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf)
> +int uart_get_rs485_mode(struct uart_port *port)
> {
> + struct serial_rs485 *rs485conf = &port->rs485;
> + struct device *dev = port->dev;
> u32 rs485_delay[2];
> int ret;
>
> @@ -3328,6 +3330,8 @@ void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf)
> rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
> rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
> }
> +
> + return 0;
> }
> EXPORT_SYMBOL_GPL(uart_get_rs485_mode);
>
> diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
> index 5e93e8d40f59..e3db54398159 100644
> --- a/drivers/tty/serial/stm32-usart.c
> +++ b/drivers/tty/serial/stm32-usart.c
> @@ -158,9 +158,7 @@ static int stm32_init_rs485(struct uart_port *port,
> if (!pdev->dev.of_node)
> return -ENODEV;
>
> - uart_get_rs485_mode(&pdev->dev, rs485conf);
> -
> - return 0;
> + return uart_get_rs485_mode(port);
> }
>
> static int stm32_pending_rx(struct uart_port *port, u32 *sr, int *last_res,
> @@ -931,7 +929,9 @@ static int stm32_init_port(struct stm32_port *stm32port,
>
> port->rs485_config = stm32_config_rs485;
>
> - stm32_init_rs485(port, pdev);
> + ret = stm32_init_rs485(port, pdev);
> + if (ret)
> + return ret;
>
> if (stm32port->info->cfg.has_wakeup) {
> stm32port->wakeirq = platform_get_irq(pdev, 1);
> diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
> index 92f5eba86052..b649a2b894e7 100644
> --- a/include/linux/serial_core.h
> +++ b/include/linux/serial_core.h
> @@ -472,5 +472,5 @@ extern int uart_handle_break(struct uart_port *port);
> (cflag) & CRTSCTS || \
> !((cflag) & CLOCAL))
>
> -void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf);
> +int uart_get_rs485_mode(struct uart_port *port);
> #endif /* LINUX_SERIAL_CORE_H */
> --
> 2.26.2
>
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2020-05-12 13:46 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-12 12:40 [PATCH v2 0/4] rs485 bus termination GPIO Lukas Wunner
2020-05-12 12:40 ` [PATCH v2 1/4] serial: 8250: Avoid error message on reprobe Lukas Wunner
2020-05-12 13:45 ` Andy Shevchenko
2020-05-12 12:40 ` [PATCH v2 2/4] serial: Allow uart_get_rs485_mode() to return errno Lukas Wunner
2020-05-12 13:46 ` Andy Shevchenko [this message]
2020-05-12 12:40 ` [PATCH v2 3/4] dt-bindings: serial: Add binding for rs485 bus termination GPIO Lukas Wunner
2020-05-12 12:40 ` [PATCH v2 4/4] serial: 8250: Support " Lukas Wunner
2020-05-12 14:09 ` Andy Shevchenko
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