* Kelvin Cheung (keguang.zhang@xxxxxxxxx) [110914 15:54]: > 2011/9/14, Andreas Barth <aba@xxxxxxxxxxxxxxx>: > > * keguang.zhang@xxxxxxxxx (keguang.zhang@xxxxxxxxx) [110914 12:49]: > >> This patch adds basic support for Loongson1B > >> including serial, timer and interrupt handler. > > > > I have a couple of questions. One of them is if it shouldn't be > > possible to add this as part of the loongson-platform, and if we > > really need a new platform. Each platform comes with some maintainence > > costs which we should try to avoid. Making things more generic is > > usually the right answer. > > I've tried to add Loongson1 to loongson-platform (acturally loongson2 > platform), but there is essential difference between them. The > loongson2 platform is something like the PC's architecture, which has > north and south bridge, while the loongson1 is SoC. > So, I think it's better that adding loongson1 as a new platform. I'm not convinced, but that's also not necessary. > >> --- /dev/null > >> +++ b/arch/mips/loongson1/common/clock.c > >> @@ -0,0 +1,164 @@ > >> +/* > >> + * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@xxxxxxxxx> > > > > Is this file not derived from any of the clock drivers we already have > > in Linux? > > > > Doesn't any of the existing clock drivers work? > > > > Is this clock part of the CPU? Otherwise it would make sense to move > > it out to the generic drivers section. What's the answer to this questions? > >> --- /dev/null > >> +++ b/arch/mips/loongson1/common/irq.c > >> @@ -0,0 +1,132 @@ > >> +/* > >> + * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@xxxxxxxxx> > >> + * > >> + * Based on Copyright (C) 2009 Lemote Inc. > > > > same question here. Also, do you have permission from Lemote to put > > the code within GPLv2? > > These code are based on the loongson platform, which is part of the > kernel code already. In that case, it would make sense to say "derived from arch/mips/..." so that other people can understand where it comes from. > >> diff --git a/arch/mips/loongson1/common/prom.c > >> b/arch/mips/loongson1/common/prom.c > >> new file mode 100644 > >> index 0000000..84a25f6 > >> --- /dev/null > >> +++ b/arch/mips/loongson1/common/prom.c > > > > Can't we re-use the prom-routines from the loongson platform here? Or > > even better, factor them out somewhere else in the mips or even > > generic linux tree? > > Same reason as question 1. Not really. Please try to de-duplicate code as far as possible, and to generalize it's usage. Having some code of the form + while (((readb(PORT(UART_BASE, UART_LSR)) & UART_LSR_THRE) == 0) + && (timeout-- > 0)) + ; + + writeb(c, PORT(UART_BASE, UART_TX)); here doesn't make too much sense to me. (Also questioning why this is part of the prom.c file). Andi
