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Subject: Re: [PATCH 4.19 150/422] tty/serial: atmel: Change the driver to work
 under at91-usart MFD
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org,
        Nicolas Ferre <nicolas.ferre@microchip.com>,
        Radu Pirea <radu_nicolae.pirea@upb.ro>
Cc:     "stable # 4 . 4+" <stable@vger.kernel.org>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Richard Genoud <richard.genoud@gmail.com>,
        Lee Jones <lee.jones@linaro.org>,
        Sasha Levin <sashal@kernel.org>
References: <20191119051400.261610025@linuxfoundation.org>
 <20191119051408.360814564@linuxfoundation.org>
From:   Richard Genoud <richard.genoud@gmail.com>
Message-ID: <86754813-17ae-46c1-f222-1635c535668e@gmail.com>
Date:   Tue, 19 Nov 2019 13:01:01 +0100
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Hi all,

Le 19/11/2019 à 06:15, Greg Kroah-Hartman a écrit :
> From: Radu Pirea <radu.pirea@microchip.com>
> 
> [ Upstream commit c24d25317a7c6bb3053d4c193b3cf57d1e9a3e4b ]
> 
> This patch modifies the place where resources and device tree properties
> are searched.

Maybe I missed something, but I don't see why this is backported to stable.
I don't think that this patch was send with a Cc: stable (I just came
back from holidays, so I may be wrong :))

Moreover, it's part of a series that introduce "config MFD_AT91_USART",
but grepping MFD_AT91_USART on stable-rc/linux-4.19.y only returns:
drivers/tty/serial/Kconfig:     select MFD_AT91_USART

So I think this is a mistake (but how it got there ? it is by a bot or
something ?)

regards,
Richard

> 
> Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Acked-by: Richard Genoud <richard.genoud@gmail.com>
> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Lee Jones <lee.jones@linaro.org>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  drivers/tty/serial/Kconfig        |  1 +
>  drivers/tty/serial/atmel_serial.c | 42 ++++++++++++++++++++-----------
>  2 files changed, 28 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index df8bd0c7b97db..32886c3046413 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -118,6 +118,7 @@ config SERIAL_ATMEL
>  	depends on ARCH_AT91 || COMPILE_TEST
>  	select SERIAL_CORE
>  	select SERIAL_MCTRL_GPIO if GPIOLIB
> +	select MFD_AT91_USART
>  	help
>  	  This enables the driver for the on-chip UARTs of the Atmel
>  	  AT91 processors.
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index dd8949e8fcd7a..251f708f47f76 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -195,8 +195,7 @@ static struct console atmel_console;
>  
>  #if defined(CONFIG_OF)
>  static const struct of_device_id atmel_serial_dt_ids[] = {
> -	{ .compatible = "atmel,at91rm9200-usart" },
> -	{ .compatible = "atmel,at91sam9260-usart" },
> +	{ .compatible = "atmel,at91rm9200-usart-serial" },
>  	{ /* sentinel */ }
>  };
>  #endif
> @@ -926,6 +925,7 @@ static void atmel_tx_dma(struct uart_port *port)
>  static int atmel_prepare_tx_dma(struct uart_port *port)
>  {
>  	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> +	struct device *mfd_dev = port->dev->parent;
>  	dma_cap_mask_t		mask;
>  	struct dma_slave_config config;
>  	int ret, nent;
> @@ -933,7 +933,7 @@ static int atmel_prepare_tx_dma(struct uart_port *port)
>  	dma_cap_zero(mask);
>  	dma_cap_set(DMA_SLAVE, mask);
>  
> -	atmel_port->chan_tx = dma_request_slave_channel(port->dev, "tx");
> +	atmel_port->chan_tx = dma_request_slave_channel(mfd_dev, "tx");
>  	if (atmel_port->chan_tx == NULL)
>  		goto chan_err;
>  	dev_info(port->dev, "using %s for tx DMA transfers\n",
> @@ -1104,6 +1104,7 @@ static void atmel_rx_from_dma(struct uart_port *port)
>  static int atmel_prepare_rx_dma(struct uart_port *port)
>  {
>  	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> +	struct device *mfd_dev = port->dev->parent;
>  	struct dma_async_tx_descriptor *desc;
>  	dma_cap_mask_t		mask;
>  	struct dma_slave_config config;
> @@ -1115,7 +1116,7 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
>  	dma_cap_zero(mask);
>  	dma_cap_set(DMA_CYCLIC, mask);
>  
> -	atmel_port->chan_rx = dma_request_slave_channel(port->dev, "rx");
> +	atmel_port->chan_rx = dma_request_slave_channel(mfd_dev, "rx");
>  	if (atmel_port->chan_rx == NULL)
>  		goto chan_err;
>  	dev_info(port->dev, "using %s for rx DMA transfers\n",
> @@ -2246,8 +2247,8 @@ static const char *atmel_type(struct uart_port *port)
>   */
>  static void atmel_release_port(struct uart_port *port)
>  {
> -	struct platform_device *pdev = to_platform_device(port->dev);
> -	int size = pdev->resource[0].end - pdev->resource[0].start + 1;
> +	struct platform_device *mpdev = to_platform_device(port->dev->parent);
> +	int size = resource_size(mpdev->resource);
>  
>  	release_mem_region(port->mapbase, size);
>  
> @@ -2262,8 +2263,8 @@ static void atmel_release_port(struct uart_port *port)
>   */
>  static int atmel_request_port(struct uart_port *port)
>  {
> -	struct platform_device *pdev = to_platform_device(port->dev);
> -	int size = pdev->resource[0].end - pdev->resource[0].start + 1;
> +	struct platform_device *mpdev = to_platform_device(port->dev->parent);
> +	int size = resource_size(mpdev->resource);
>  
>  	if (!request_mem_region(port->mapbase, size, "atmel_serial"))
>  		return -EBUSY;
> @@ -2365,27 +2366,28 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
>  {
>  	int ret;
>  	struct uart_port *port = &atmel_port->uart;
> +	struct platform_device *mpdev = to_platform_device(pdev->dev.parent);
>  
>  	atmel_init_property(atmel_port, pdev);
>  	atmel_set_ops(port);
>  
> -	uart_get_rs485_mode(&pdev->dev, &port->rs485);
> +	uart_get_rs485_mode(&mpdev->dev, &port->rs485);
>  
>  	port->iotype		= UPIO_MEM;
>  	port->flags		= UPF_BOOT_AUTOCONF | UPF_IOREMAP;
>  	port->ops		= &atmel_pops;
>  	port->fifosize		= 1;
>  	port->dev		= &pdev->dev;
> -	port->mapbase	= pdev->resource[0].start;
> -	port->irq	= pdev->resource[1].start;
> +	port->mapbase		= mpdev->resource[0].start;
> +	port->irq		= mpdev->resource[1].start;
>  	port->rs485_config	= atmel_config_rs485;
> -	port->membase	= NULL;
> +	port->membase		= NULL;
>  
>  	memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
>  
>  	/* for console, the clock could already be configured */
>  	if (!atmel_port->clk) {
> -		atmel_port->clk = clk_get(&pdev->dev, "usart");
> +		atmel_port->clk = clk_get(&mpdev->dev, "usart");
>  		if (IS_ERR(atmel_port->clk)) {
>  			ret = PTR_ERR(atmel_port->clk);
>  			atmel_port->clk = NULL;
> @@ -2718,13 +2720,22 @@ static void atmel_serial_probe_fifos(struct atmel_uart_port *atmel_port,
>  static int atmel_serial_probe(struct platform_device *pdev)
>  {
>  	struct atmel_uart_port *atmel_port;
> -	struct device_node *np = pdev->dev.of_node;
> +	struct device_node *np = pdev->dev.parent->of_node;
>  	void *data;
>  	int ret = -ENODEV;
>  	bool rs485_enabled;
>  
>  	BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
>  
> +	/*
> +	 * In device tree there is no node with "atmel,at91rm9200-usart-serial"
> +	 * as compatible string. This driver is probed by at91-usart mfd driver
> +	 * which is just a wrapper over the atmel_serial driver and
> +	 * spi-at91-usart driver. All attributes needed by this driver are
> +	 * found in of_node of parent.
> +	 */
> +	pdev->dev.of_node = np;
> +
>  	ret = of_alias_get_id(np, "serial");
>  	if (ret < 0)
>  		/* port id not found in platform data nor device-tree aliases:
> @@ -2860,6 +2871,7 @@ static int atmel_serial_remove(struct platform_device *pdev)
>  
>  	clk_put(atmel_port->clk);
>  	atmel_port->clk = NULL;
> +	pdev->dev.of_node = NULL;
>  
>  	return ret;
>  }
> @@ -2870,7 +2882,7 @@ static struct platform_driver atmel_serial_driver = {
>  	.suspend	= atmel_serial_suspend,
>  	.resume		= atmel_serial_resume,
>  	.driver		= {
> -		.name			= "atmel_usart",
> +		.name			= "atmel_usart_serial",
>  		.of_match_table		= of_match_ptr(atmel_serial_dt_ids),
>  	},
>  };
>