| Message ID | 20240706101856.3077-1-jszhang@kernel.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | serial: 8250: move mmp|pxa uart earlycon code and add xscale earlycon | expand |
Hi On 18:18 Sat 06 Jul , Jisheng Zhang wrote: > There are two other drivers that bind to "mrvl,mmp-uart": the 8250_of > and the 8250_pxa. The previous one is generic and the latter is binded > to ARCH_PXA || ARCH_MMP. Now we may have pxa programming compatible > HW to support, making use of the generic 8250_of seems a good idea. > However, there's no earlycon support if we go with this solution. So > move the mmp|pxa-uart earlycon code to core 8250_early.c. > > At the same, add xscale earlycon support too, only build test since > I have no xscale machine any more. > > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > --- > drivers/tty/serial/8250/8250_early.c | 11 +++++++++++ > drivers/tty/serial/8250/8250_pxa.c | 16 ---------------- > 2 files changed, 11 insertions(+), 16 deletions(-) > > diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c > index e3f482fd3de4..6176083d0341 100644 > --- a/drivers/tty/serial/8250/8250_early.c > +++ b/drivers/tty/serial/8250/8250_early.c > @@ -171,6 +171,17 @@ OF_EARLYCON_DECLARE(ns16550a, "ns16550a", early_serial8250_setup); > OF_EARLYCON_DECLARE(uart, "nvidia,tegra20-uart", early_serial8250_setup); > OF_EARLYCON_DECLARE(uart, "snps,dw-apb-uart", early_serial8250_setup); > > +static int __init early_serial8250_rs2_setup(struct earlycon_device *device, > + const char *options) > +{ > + device->port.regshift = 2; just wondering if possible to introduce a generic earlycon sub option? so kernel can parse reg-shift from command line parameter instead of hardcoding here, which would benefit more drivers (potentially without adding more OF_EARLYCON_DECLAREs..) I mean something like this: Documentation/admin-guide/kernel-parameters.txt uart[8250],mmio32,<addr>[,options[,reg-shift=0,1,2,4 ..]] > + > + return early_serial8250_setup(device, options); > +} > +OF_EARLYCON_DECLARE(uart, "intel,xscale-uart", early_serial8250_rs2_setup); > +OF_EARLYCON_DECLARE(uart, "mrvl,mmp-uart", early_serial8250_rs2_setup); > +OF_EARLYCON_DECLARE(uart, "mrvl,pxa-uart", early_serial8250_rs2_setup); > + > #ifdef CONFIG_SERIAL_8250_OMAP > > static int __init early_omap8250_setup(struct earlycon_device *device, > diff --git a/drivers/tty/serial/8250/8250_pxa.c b/drivers/tty/serial/8250/8250_pxa.c > index ba96fa913e7f..b5d937f6f3f9 100644 > --- a/drivers/tty/serial/8250/8250_pxa.c > +++ b/drivers/tty/serial/8250/8250_pxa.c > @@ -165,22 +165,6 @@ static struct platform_driver serial_pxa_driver = { > > module_platform_driver(serial_pxa_driver); > > -#ifdef CONFIG_SERIAL_8250_CONSOLE > -static int __init early_serial_pxa_setup(struct earlycon_device *device, > - const char *options) > -{ > - struct uart_port *port = &device->port; > - > - if (!(device->port.membase || device->port.iobase)) > - return -ENODEV; > - > - port->regshift = 2; > - return early_serial8250_setup(device, NULL); > -} > -OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup); > -OF_EARLYCON_DECLARE(mmp, "mrvl,mmp-uart", early_serial_pxa_setup); > -#endif > - > MODULE_AUTHOR("Sergei Ianovich"); > MODULE_LICENSE("GPL"); > MODULE_ALIAS("platform:pxa2xx-uart"); > -- > 2.43.0 >
On Sat, Jul 06, 2024 at 10:33:23PM +0000, Yixun Lan wrote: > Hi > On 18:18 Sat 06 Jul , Jisheng Zhang wrote: > > There are two other drivers that bind to "mrvl,mmp-uart": the 8250_of > > and the 8250_pxa. The previous one is generic and the latter is binded > > to ARCH_PXA || ARCH_MMP. Now we may have pxa programming compatible > > HW to support, making use of the generic 8250_of seems a good idea. > > However, there's no earlycon support if we go with this solution. So > > move the mmp|pxa-uart earlycon code to core 8250_early.c. > > > > At the same, add xscale earlycon support too, only build test since > > I have no xscale machine any more. > > > > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > > --- > > drivers/tty/serial/8250/8250_early.c | 11 +++++++++++ > > drivers/tty/serial/8250/8250_pxa.c | 16 ---------------- > > 2 files changed, 11 insertions(+), 16 deletions(-) > > > > diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c > > index e3f482fd3de4..6176083d0341 100644 > > --- a/drivers/tty/serial/8250/8250_early.c > > +++ b/drivers/tty/serial/8250/8250_early.c > > @@ -171,6 +171,17 @@ OF_EARLYCON_DECLARE(ns16550a, "ns16550a", early_serial8250_setup); > > OF_EARLYCON_DECLARE(uart, "nvidia,tegra20-uart", early_serial8250_setup); > > OF_EARLYCON_DECLARE(uart, "snps,dw-apb-uart", early_serial8250_setup); > > > > +static int __init early_serial8250_rs2_setup(struct earlycon_device *device, > > + const char *options) > > +{ > > + device->port.regshift = 2; > just wondering if possible to introduce a generic earlycon sub option? so kernel the 8250 ealycon can parse reg-shift from dt too, so no sub option is needed. The reason I hardcoded here is: pxa-uart and xscale-uart doesn't mandate "reg-shift" property in the binding, while I did see mmp-uart mentions "reg-shift" is required in the DT binding. > can parse reg-shift from command line parameter instead of hardcoding here, > which would benefit more drivers (potentially without adding more OF_EARLYCON_DECLAREs..) > > I mean something like this: > Documentation/admin-guide/kernel-parameters.txt > uart[8250],mmio32,<addr>[,options[,reg-shift=0,1,2,4 ..]] > > > + > > + return early_serial8250_setup(device, options); > > +} > > +OF_EARLYCON_DECLARE(uart, "intel,xscale-uart", early_serial8250_rs2_setup); > > +OF_EARLYCON_DECLARE(uart, "mrvl,mmp-uart", early_serial8250_rs2_setup); > > +OF_EARLYCON_DECLARE(uart, "mrvl,pxa-uart", early_serial8250_rs2_setup); > > + > > #ifdef CONFIG_SERIAL_8250_OMAP > > > > static int __init early_omap8250_setup(struct earlycon_device *device, > > diff --git a/drivers/tty/serial/8250/8250_pxa.c b/drivers/tty/serial/8250/8250_pxa.c > > index ba96fa913e7f..b5d937f6f3f9 100644 > > --- a/drivers/tty/serial/8250/8250_pxa.c > > +++ b/drivers/tty/serial/8250/8250_pxa.c > > @@ -165,22 +165,6 @@ static struct platform_driver serial_pxa_driver = { > > > > module_platform_driver(serial_pxa_driver); > > > > -#ifdef CONFIG_SERIAL_8250_CONSOLE > > -static int __init early_serial_pxa_setup(struct earlycon_device *device, > > - const char *options) > > -{ > > - struct uart_port *port = &device->port; > > - > > - if (!(device->port.membase || device->port.iobase)) > > - return -ENODEV; > > - > > - port->regshift = 2; > > - return early_serial8250_setup(device, NULL); > > -} > > -OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup); > > -OF_EARLYCON_DECLARE(mmp, "mrvl,mmp-uart", early_serial_pxa_setup); > > -#endif > > - > > MODULE_AUTHOR("Sergei Ianovich"); > > MODULE_LICENSE("GPL"); > > MODULE_ALIAS("platform:pxa2xx-uart"); > > -- > > 2.43.0 > > > > -- > Yixun Lan (dlan) > Gentoo Linux Developer > GPG Key ID AABEFD55
diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c index e3f482fd3de4..6176083d0341 100644 --- a/drivers/tty/serial/8250/8250_early.c +++ b/drivers/tty/serial/8250/8250_early.c @@ -171,6 +171,17 @@ OF_EARLYCON_DECLARE(ns16550a, "ns16550a", early_serial8250_setup); OF_EARLYCON_DECLARE(uart, "nvidia,tegra20-uart", early_serial8250_setup); OF_EARLYCON_DECLARE(uart, "snps,dw-apb-uart", early_serial8250_setup); +static int __init early_serial8250_rs2_setup(struct earlycon_device *device, + const char *options) +{ + device->port.regshift = 2; + + return early_serial8250_setup(device, options); +} +OF_EARLYCON_DECLARE(uart, "intel,xscale-uart", early_serial8250_rs2_setup); +OF_EARLYCON_DECLARE(uart, "mrvl,mmp-uart", early_serial8250_rs2_setup); +OF_EARLYCON_DECLARE(uart, "mrvl,pxa-uart", early_serial8250_rs2_setup); + #ifdef CONFIG_SERIAL_8250_OMAP static int __init early_omap8250_setup(struct earlycon_device *device, diff --git a/drivers/tty/serial/8250/8250_pxa.c b/drivers/tty/serial/8250/8250_pxa.c index ba96fa913e7f..b5d937f6f3f9 100644 --- a/drivers/tty/serial/8250/8250_pxa.c +++ b/drivers/tty/serial/8250/8250_pxa.c @@ -165,22 +165,6 @@ static struct platform_driver serial_pxa_driver = { module_platform_driver(serial_pxa_driver); -#ifdef CONFIG_SERIAL_8250_CONSOLE -static int __init early_serial_pxa_setup(struct earlycon_device *device, - const char *options) -{ - struct uart_port *port = &device->port; - - if (!(device->port.membase || device->port.iobase)) - return -ENODEV; - - port->regshift = 2; - return early_serial8250_setup(device, NULL); -} -OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup); -OF_EARLYCON_DECLARE(mmp, "mrvl,mmp-uart", early_serial_pxa_setup); -#endif - MODULE_AUTHOR("Sergei Ianovich"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:pxa2xx-uart");
There are two other drivers that bind to "mrvl,mmp-uart": the 8250_of and the 8250_pxa. The previous one is generic and the latter is binded to ARCH_PXA || ARCH_MMP. Now we may have pxa programming compatible HW to support, making use of the generic 8250_of seems a good idea. However, there's no earlycon support if we go with this solution. So move the mmp|pxa-uart earlycon code to core 8250_early.c. At the same, add xscale earlycon support too, only build test since I have no xscale machine any more. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> --- drivers/tty/serial/8250/8250_early.c | 11 +++++++++++ drivers/tty/serial/8250/8250_pxa.c | 16 ---------------- 2 files changed, 11 insertions(+), 16 deletions(-)