On Tue, Aug 06, 2019 at 12:43:19PM +0300, Andy Shevchenko wrote:
> For Synopsys DesignWare 8250 uart which version >= 4.00a, there's a
> valid divisor latch fraction register.
>
> Now the preparation is done, it's easy to add the feature support.
> This patch firstly tries to get the fractional divisor width during
> probe, then setups specific get_divisor() and set_divisor() hook.
>
> Among other changes the FIFO size is now retrieved from the hardware.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
FWIW:
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/tty/serial/8250/8250_lpss.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
> index 3bf23770c188..0c6aa990db3d 100644
> --- a/drivers/tty/serial/8250/8250_lpss.c
> +++ b/drivers/tty/serial/8250/8250_lpss.c
> @@ -113,7 +113,6 @@ static unsigned int byt_get_mctrl(struct uart_port *port)
> static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
> {
> struct dw_dma_slave *param = &lpss->dma_param;
> - struct uart_8250_port *up = up_to_u8250p(port);
> struct pci_dev *pdev = to_pci_dev(port->dev);
> unsigned int dma_devfn = PCI_DEVFN(PCI_SLOT(pdev->devfn), 0);
> struct pci_dev *dma_dev = pci_get_slot(pdev->bus, dma_devfn);
> @@ -139,10 +138,6 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
> param->m_master = 0;
> param->p_master = 1;
>
> - /* TODO: Detect FIFO size automaticaly for DesignWare 8250 */
> - port->fifosize = 64;
> - up->tx_loadsz = 64;
> -
> lpss->dma_maxburst = 16;
>
> port->set_termios = byt_set_termios;
> @@ -316,6 +311,8 @@ static int lpss8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> if (ret)
> return ret;
>
> + dw8250_setup_port(&uart.port);
> +
> ret = lpss8250_dma_setup(lpss, &uart);
> if (ret)
> goto err_exit;
> --
> 2.20.1
--
heikki
