>-----Original Message----- >From: Mark Rutland [mailto:mark.rutland@xxxxxxx] >Sent: Thursday, July 03, 2014 11:12 PM >To: Lu Jingchang-B35083 >Cc: Guo Shawn-R65073; shawn.guo@xxxxxxxxxx; linux-arm- >kernel@xxxxxxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx >Subject: Re: [PATCH 4/5] ARM: imx: Add initial support for Freescale >LS1021A > >On Thu, Jul 03, 2014 at 11:17:12AM +0100, Jingchang Lu wrote: >> >-----Original Message----- >> >From: Mark Rutland [mailto:mark.rutland@xxxxxxx] >> >Sent: Wednesday, July 02, 2014 7:21 PM >> >To: Lu Jingchang-B35083 >> >Cc: shawn.guo@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; >> >devicetree@xxxxxxxxxxxxxxx; Lu Jingchang-B35083 >> >Subject: Re: [PATCH 4/5] ARM: imx: Add initial support for Freescale >> >LS1021A >> > >> >On Wed, Jul 02, 2014 at 10:02:51AM +0100, Jingchang Lu wrote: >> >> From: Jingchang Lu <b35083@xxxxxxxxxxxxx> >> >> >> >> diff --git a/arch/arm/mach-imx/mach-ls1021a.c >> >> b/arch/arm/mach-imx/mach-ls1021a.c >> >> new file mode 100644 >> >> index 0000000..d1a9bb9 >> >> --- /dev/null >> >> +++ b/arch/arm/mach-imx/mach-ls1021a.c >> >> @@ -0,0 +1,49 @@ >> >> +/* >> >> + * Copyright 2013-2014 Freescale Semiconductor, Inc. >> >> + * >> >> + * This program is free software; you can redistribute it and/or >> >> +modify >> >> + * it under the terms of the GNU General Public License as >> >> +published by >> >> + * the Free Software Foundation; either version 2 of the License, >> >> +or >> >> + * (at your option) any later version. >> >> + */ >> >> + >> >> +#include <linux/of_platform.h> >> >> +#include <asm/mach/arch.h> >> >> + >> >> +#include "common.h" >> >> + >> >> +static const struct of_device_id of_ls1021a_match_table[] = { >> >> + { >> >> + .compatible = "simple-bus", >> >> + }, >> >> + { >> >> + .compatible = "fsl,ifc", >> >> + }, >> >> + { >> >> + .compatible = "fsl,fpga-qixis", >> >> + }, >> >> + { >> >> + .compatible = "fsl,qe", >> >> + }, >> >> + {} >> >> +}; >> > >> >Are any of thse not always-on (or default-on) MMIO busses? >> > >> >Is there any reason for not giving them their own drivers? >> > >> Normally these are always-on. The child nodes are handled by different >> drivers, so to make the devices being added by the of system, they are >claimed here. >> Thanks. > >If these are always-on MMIO busses, is there any reason these can't have >"simple-bus" as a fallback in their compatible lists in the DT? They would >seemd to be compatible with it given they are in the table above... > >That way we don't need the table at all, and we can always add drivers for >them later if we need them... Yes, if they can work well with the default "simple-bus", I will change to it, I will try this. Thanks. > >> >> + >> >> +static void __init ls1021a_init_machine(void) { >> >> + mxc_arch_reset_init_dt(); >> > >> >This looks to only be used to set up a watchdog timer. Is there any >> >reason this logic can't be moved to the watchdog timer driver? >> > >> >> + >> >> +DT_MACHINE_START(LS1021A, "Freescale LS1021A") #ifdef >CONFIG_ZONE_DMA >> >> + .dma_zone_size = SZ_128M, >> >> +#endif >> >> + .init_machine = ls1021a_init_machine, >> >> + .dt_compat = ls1021a_dt_compat, >> >> + .restart = mxc_restart, >> > >> >AFAICT, that jsut uses the WDT for restart. Why can't the watchdog >> >driver register itself as a restart device? >> > >> >That would bring us close to an empty machine descriptor, and enable >> >reuse of the WDT and those busses. >> > >> >Thanks, >> >Mark. >> Yes, we use the watchdog timer for restart, just as i.MX and Vybrid, >> the WDT as a common driver it is still work for watchdog. Thanks. > >That doesn't answer the question of why the restart code (and registration >thereof) can't live in the WDT driver. > >Thanks, >Mark. Several i.MX SoCs have used this mxc_restart currently, and the watchdog driver is shared between them, if here move it to the driver layer, all others needs changes accordingly. So I think if that is preferred, we can move it together some times later. And BTW, what's the preferred restart register manner in the driver, just assign to the arm_pm_restart? Thanks. Best Regards, Jingchang ��.n��������+%������w��{.n����z�{��ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
