On Tue, Jul 04, 2023 at 05:29:57PM +0200, neil.armstrong@xxxxxxxxxx wrote: > Hi. > > On 04/07/2023 16:59, Dmitry Rokosov wrote: > > Hello Neil, > > > > Thank you for quick feedback! > > > > On Tue, Jul 04, 2023 at 04:42:39PM +0200, neil.armstrong@xxxxxxxxxx wrote: > > > On 04/07/2023 15:59, Dmitry Rokosov wrote: > > > > It is worth noting that the devname ttyS is a widely recognized tty name > > > > and is commonly used by many uart device drivers. Given the established > > > > usage and compatibility concerns, it may not be feasible to change the > > > > devname for older SoCs. However, for new definitions, it is acceptable > > > > and even recommended to use a new devname to help ensure clarity and > > > > avoid any potential conflicts on lower or upper software levels. In > > > > addition, modify the meson_uart_dt match data for g12a, a1, and s4 to > > > > their appropriate values to ensure proper devname values and > > > > functionality. > > > > > > I'm not confident about modifying a global struct from a probe, > > > I think you should add a separate meson_uart_driver/meson_serial_console couple > > > with ttyS instead of ttyAML, refer to the right uart_driver in meson_uart_data > > > and in probe() register it and pass it to uart_add_one_port(). > > > > Could you provide some insight into why you believe this solution may > > not be acceptable? It appears that the meson_uart_driver and > > meson_serial_console are not labeled with __init, which means it stay in > > memory forever. > Yes but nothing forbids registering a g12a and an a1 uart on the same system, > but you modify the meson_uart_driver/meson_serial_console struct. > This could cause some issues. > > In practice this will never happen, but since we don't control the DT passed > to the system we must make sure we take in account any scenario. > Yep, agree, this will cause an issue. > > > > To clarify, are you suggesting a solution that involves segregating the > > meson_uart_driver and meson_serial_console objects for each scenario and > > subsequently declaring pointers to both objects within the > > meson_uart_data? I want to make sure that I have accurately grasped the > > essence of your proposed approach. > > Not both, only the appropriate one. > > So either we make sure ttyAML and ttyS at exclusive at runtime, in this case we can > modify the global meson_uart_driver/meson_serial_console, or you add > a second set of uart_driver/console structs to handle this improbable case. Got it, thank you for explanation! I will prepare the v2. > > > > > > > > > > For more information please refer to IRC discussion at [1]. > > > > > > > > Links: > > > > [1]: https://libera.irclog.whitequark.org/linux-amlogic/2023-07-03 > > > > > > > > Signed-off-by: Dmitry Rokosov <ddrokosov@xxxxxxxxxxxxxx> > > > > --- > > > > drivers/tty/serial/meson_uart.c | 33 +++++++++++++++++++++++++++++++-- > > > > 1 file changed, 31 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c > > > > index 87c0eb5f2dba..361f9326b527 100644 > > > > --- a/drivers/tty/serial/meson_uart.c > > > > +++ b/drivers/tty/serial/meson_uart.c > > > > @@ -82,6 +82,7 @@ static struct uart_driver meson_uart_driver; > > > > static struct uart_port *meson_ports[AML_UART_PORT_NUM]; > > > > struct meson_uart_data { > > > > + const char *dev_name; > > > > bool has_xtal_div2; > > > > }; > > > > @@ -683,6 +684,7 @@ static int meson_uart_probe_clocks(struct platform_device *pdev, > > > > static int meson_uart_probe(struct platform_device *pdev) > > > > { > > > > + const struct meson_uart_data *priv_data; > > > > struct resource *res_mem; > > > > struct uart_port *port; > > > > u32 fifosize = 64; /* Default is 64, 128 for EE UART_0 */ > > > > @@ -729,6 +731,18 @@ static int meson_uart_probe(struct platform_device *pdev) > > > > if (ret) > > > > return ret; > > > > + priv_data = device_get_match_data(&pdev->dev); > > > > + > > > > + if (priv_data) { > > > > + struct console *cons = meson_uart_driver.cons; > > > > + > > > > + meson_uart_driver.dev_name = priv_data->dev_name; > > > > + > > > > + if (cons) > > > > + strscpy(cons->name, priv_data->dev_name, > > > > + sizeof(cons->name)); > > > > + } > > > > + > > > > if (!meson_uart_driver.state) { > > > > ret = uart_register_driver(&meson_uart_driver); > > > > if (ret) > > > > @@ -748,7 +762,7 @@ static int meson_uart_probe(struct platform_device *pdev) > > > > port->x_char = 0; > > > > port->ops = &meson_uart_ops; > > > > port->fifosize = fifosize; > > > > - port->private_data = (void *)device_get_match_data(&pdev->dev); > > > > + port->private_data = (void *)priv_data; > > > > meson_ports[pdev->id] = port; > > > > platform_set_drvdata(pdev, port); > > > > @@ -780,6 +794,17 @@ static int meson_uart_remove(struct platform_device *pdev) > > > > } > > > > static struct meson_uart_data meson_g12a_uart_data = { > > > > + .dev_name = "ttyAML", > > > > + .has_xtal_div2 = true, > > > > +}; > > > > + > > > > +static struct meson_uart_data meson_a1_uart_data = { > > > > + .dev_name = "ttyS", > > > > + .has_xtal_div2 = false, > > > > +}; > > > > + > > > > +static struct meson_uart_data meson_s4_uart_data = { > > > > + .dev_name = "ttyS", > > > > .has_xtal_div2 = true, > > > > }; > > > > @@ -794,7 +819,11 @@ static const struct of_device_id meson_uart_dt_match[] = { > > > > }, > > > > { > > > > .compatible = "amlogic,meson-s4-uart", > > > > - .data = (void *)&meson_g12a_uart_data, > > > > + .data = (void *)&meson_s4_uart_data, > > > > + }, > > > > + { > > > > + .compatible = "amlogic,meson-a1-uart", > > > > + .data = (void *)&meson_a1_uart_data, > > > > }, > > > > { /* sentinel */ }, > > > > }; > > > > > > -- Thank you, Dmitry
