Re: [PATCH v3 6/6] tty/serial: atmel: changed the driver to work under at91-usart mfd

From: Radu Pirea
Date: Tue May 15 2018 - 13:38:27 EST


On Mon, 2018-05-14 at 12:57 +0200, Richard Genoud wrote:
> Hi,
>
> On 11/05/2018 12:38, Radu Pirea wrote:
> > This patch modifies the place where resources and device tree
> > properties
> > are searched.
> >
> > Signed-off-by: Radu Pirea <radu.pirea@xxxxxxxxxxxxx>
> > ---
> > drivers/tty/serial/Kconfig | 1 +
> > drivers/tty/serial/atmel_serial.c | 29 +++++++++++++++----------
> > ----
> > 2 files changed, 16 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/tty/serial/Kconfig
> > b/drivers/tty/serial/Kconfig
> > index 3682fd3e960c..25e55332f8b1 100644
> > --- a/drivers/tty/serial/Kconfig
> > +++ b/drivers/tty/serial/Kconfig
> > @@ -119,6 +119,7 @@ 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 df46a9e88c34..6b4494352853 100644
> > --- a/drivers/tty/serial/atmel_serial.c
> > +++ b/drivers/tty/serial/atmel_serial.c
> > @@ -193,8 +193,8 @@ 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" },
> > + { .compatible = "atmel,at91sam9260-usart-serial" },
> > { /* sentinel */ }
> > };
> > #endif
> > @@ -1631,7 +1631,7 @@ static void atmel_tasklet_tx_func(unsigned
> > long data)
> > static void atmel_init_property(struct atmel_uart_port
> > *atmel_port,
> > struct platform_device *pdev)
> > {
> > - struct device_node *np = pdev->dev.of_node;
> > + struct device_node *np = pdev->dev.parent->of_node;
> >
> > /* DMA/PDC usage specification */
> > if (of_property_read_bool(np, "atmel,use-dma-rx")) {
> > @@ -2223,7 +2223,8 @@ 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;
> > + int size = to_platform_device(pdev->dev.parent)-
> > >resource[0].end -
> > + to_platform_device(pdev->dev.parent)-
> > >resource[0].start + 1;
>
> I think it may be simpler with something like:
> + struct platform_device *mfd_pdev = to_platform_device(port-
> >dev->parent);
> + int size = mfd_pdev->resource[0].end - mfd_pdev-
> >resource[0].start + 1;
>
> >
> > release_mem_region(port->mapbase, size);
> >
> > @@ -2239,7 +2240,8 @@ 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;
> > + int size = to_platform_device(pdev->dev.parent)-
> > >resource[0].end -
> > + to_platform_device(pdev->dev.parent)-
> > >resource[0].start + 1;
> >
>
> ditto
>
> > if (!request_mem_region(port->mapbase, size,
> > "atmel_serial"))
> > return -EBUSY;
> > @@ -2345,23 +2347,23 @@ static int atmel_init_port(struct
> > atmel_uart_port *atmel_port,
>
> Here, we could also add:
> + struct device *mfd_dev = pdev->dev.parent;
> + struct platform_device *mfd_pdev =
> to_platform_device(mfd_dev);
>
> > atmel_init_property(atmel_port, pdev);
> > atmel_set_ops(port);
> >
> > - uart_get_rs485_mode(&pdev->dev, &port->rs485);
> > + uart_get_rs485_mode(pdev->dev.parent, &port->rs485);
>
> ...and use them here
>
> >
> > 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 = to_platform_device(pdev-
> > >dev.parent)->resource[0].start;
> > + port->irq = to_platform_device(pdev-
> > >dev.parent)->resource[1].start;
>
> and here
> I think it would be easier to read.
>
> > 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(pdev->dev.parent,
> > "usart");
>
> and here
>
> > if (IS_ERR(atmel_port->clk)) {
> > ret = PTR_ERR(atmel_port->clk);
> > atmel_port->clk = NULL;
> > @@ -2656,7 +2658,7 @@ static void atmel_serial_probe_fifos(struct
> > atmel_uart_port *atmel_port,
> > atmel_port->rts_low = 0;
> > atmel_port->rts_high = 0;
> >
> > - if (of_property_read_u32(pdev->dev.of_node,
> > + if (of_property_read_u32(pdev->dev.parent->of_node,
> > "atmel,fifo-size",
> > &atmel_port->fifo_size))
> > return;
> > @@ -2694,11 +2696,10 @@ 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;
> > -
>
> I think this line feed wasn't so bad.
>
> > BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE &
> > (ATMEL_SERIAL_RINGSIZE - 1));
> >
> > ret = of_alias_get_id(np, "serial");
> > @@ -2845,7 +2846,7 @@ 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),
> > },
> > };
> >
>
> After your patch, the DMA is not selected anymore:
> atmel_usart_serial atmel_usart_serial.0.auto: TX channel not
> available, switch to pio
> instead of:
> atmel_usart fffff200.serial: using dma1chan2 for tx DMA transfers
>
Fixed.
> And the kernel doesn't log anymore on the serial console, despite the
> loglevel=8
> (after reverting this series, the kernel logs reappears on the serial
> console)
>
Which serial are you using as console?
> (tests done on sam9g35)
>
I will consider the rest of suggestions.
> regards,
> Richard
>

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