Re: [PATCH] powerpc/4xx: Add optional "reset_type" property to control reboot via dts
Hi Josh, On Monday 26 April 2010 20:28:29 Josh Boyer wrote: > On Mon, Apr 26, 2010 at 03:39:01PM +0200, Stefan Roese wrote: > >By setting "reset_type" to one of the following values, the default > >software reset mechanism may be overidden. Here the possible values of > > >"reset_type": > NEAT! A 4xx patch! I haven't gotten enough of these lately, so forgive my > nit picking ;) Sure. Comments welcome, as always. > > 1 - PPC4xx core reset > > 2 - PPC4xx chip reset > > 3 - PPC4xx system reset (default) > > We should probably put a brief description of this in the dts bindings > under Documentation (or whereever we're storing them these days. I saw > something about a wiki?). Right. I thought about this as well (too late). I'll include a short documentation in my next patch version. > Also, while it's not a large issue, I wonder if there will be confusion on > whether 'reset-type' is "the type of reset to use" or "the type of reset > that was just done". There are some products that actually care about the > latter for various RAS issues. I don't, however, have a great alternative > property name that comes to mind though. I'll stick with this name for now then. > >This will be used by a new PPC440SPe board port, which needs a "chip > >reset" instead of the default "system reset" to be asserted. > > I'm curious why that is? Hmmm. Frankly, I can't remember the background here. You might what to check this for yourself. Katmai has the same issue. And I just copied this reboot code from Katmai for this new 440SPe board. BTW: Once this patch is finished/accepted, I'll cook up a short katmai patch to fix this reboot issue here too. > >Signed-off-by: Stefan Roese > >Cc: Josh Boyer > >Cc: Benjamin Herrenschmidt > >--- > > > > arch/powerpc/sysdev/ppc4xx_soc.c | 17 +++-- > > 1 files changed, 15 insertions(+), 2 deletions(-) > > > >diff --git a/arch/powerpc/sysdev/ppc4xx_soc.c > >b/arch/powerpc/sysdev/ppc4xx_soc.c index 5c01435..fe54216 100644 > >--- a/arch/powerpc/sysdev/ppc4xx_soc.c > >+++ b/arch/powerpc/sysdev/ppc4xx_soc.c > >@@ -191,11 +191,24 @@ static int __init ppc4xx_l2c_probe(void) > > > > arch_initcall(ppc4xx_l2c_probe); > > > > /* > > > >- * At present, this routine just applies a system reset. > >+ * Apply a system reset. Alternatively a board specific value may be > >+ * provided via the "reset-type" property in the cpu node. > > > > */ > > > > void ppc4xx_reset_system(char *cmd) > > { > > > >-mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_RST_SYSTEM); > >+struct device_node *np; > >+u32 reset_type = DBCR0_RST_SYSTEM; > >+const u32 *prop; > >+ > >+np = of_find_node_by_type(NULL, "cpu"); > >+if (np) { > >+prop = of_get_property(np, "reset-type", NULL); > >+if (prop) > >+reset_type = prop[0] << 28; > >+} > > While I don't think it's a big issue, I wonder if we should sanity check > the resulting value here. I could see someone being dumb and doing: > > reset-type = "system"; > > or something like that. If that is done, what would the resulting shift on > it turn into? Good idea. I'll add a check in the next version. Thanks. Cheers, Stefan ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH] powerpc/4xx: Add optional "reset_type" property to control reboot via dts
On Mon, Apr 26, 2010 at 03:39:01PM +0200, Stefan Roese wrote: >By setting "reset_type" to one of the following values, the default >software reset mechanism may be overidden. Here the possible values of >"reset_type": NEAT! A 4xx patch! I haven't gotten enough of these lately, so forgive my nit picking ;) > > 1 - PPC4xx core reset > 2 - PPC4xx chip reset > 3 - PPC4xx system reset (default) We should probably put a brief description of this in the dts bindings under Documentation (or whereever we're storing them these days. I saw something about a wiki?). Also, while it's not a large issue, I wonder if there will be confusion on whether 'reset-type' is "the type of reset to use" or "the type of reset that was just done". There are some products that actually care about the latter for various RAS issues. I don't, however, have a great alternative property name that comes to mind though. >This will be used by a new PPC440SPe board port, which needs a "chip >reset" instead of the default "system reset" to be asserted. I'm curious why that is? >Signed-off-by: Stefan Roese >Cc: Josh Boyer >Cc: Benjamin Herrenschmidt >--- > arch/powerpc/sysdev/ppc4xx_soc.c | 17 +++-- > 1 files changed, 15 insertions(+), 2 deletions(-) > >diff --git a/arch/powerpc/sysdev/ppc4xx_soc.c >b/arch/powerpc/sysdev/ppc4xx_soc.c >index 5c01435..fe54216 100644 >--- a/arch/powerpc/sysdev/ppc4xx_soc.c >+++ b/arch/powerpc/sysdev/ppc4xx_soc.c >@@ -191,11 +191,24 @@ static int __init ppc4xx_l2c_probe(void) > arch_initcall(ppc4xx_l2c_probe); > > /* >- * At present, this routine just applies a system reset. >+ * Apply a system reset. Alternatively a board specific value may be >+ * provided via the "reset-type" property in the cpu node. > */ > void ppc4xx_reset_system(char *cmd) > { >- mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_RST_SYSTEM); >+ struct device_node *np; >+ u32 reset_type = DBCR0_RST_SYSTEM; >+ const u32 *prop; >+ >+ np = of_find_node_by_type(NULL, "cpu"); >+ if (np) { >+ prop = of_get_property(np, "reset-type", NULL); >+ if (prop) >+ reset_type = prop[0] << 28; >+ } While I don't think it's a big issue, I wonder if we should sanity check the resulting value here. I could see someone being dumb and doing: reset-type = "system"; or something like that. If that is done, what would the resulting shift on it turn into? josh ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
[PATCH] powerpc/4xx: Add optional "reset_type" property to control reboot via dts
By setting "reset_type" to one of the following values, the default software reset mechanism may be overidden. Here the possible values of "reset_type": 1 - PPC4xx core reset 2 - PPC4xx chip reset 3 - PPC4xx system reset (default) This will be used by a new PPC440SPe board port, which needs a "chip reset" instead of the default "system reset" to be asserted. Signed-off-by: Stefan Roese Cc: Josh Boyer Cc: Benjamin Herrenschmidt --- arch/powerpc/sysdev/ppc4xx_soc.c | 17 +++-- 1 files changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/sysdev/ppc4xx_soc.c b/arch/powerpc/sysdev/ppc4xx_soc.c index 5c01435..fe54216 100644 --- a/arch/powerpc/sysdev/ppc4xx_soc.c +++ b/arch/powerpc/sysdev/ppc4xx_soc.c @@ -191,11 +191,24 @@ static int __init ppc4xx_l2c_probe(void) arch_initcall(ppc4xx_l2c_probe); /* - * At present, this routine just applies a system reset. + * Apply a system reset. Alternatively a board specific value may be + * provided via the "reset-type" property in the cpu node. */ void ppc4xx_reset_system(char *cmd) { - mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_RST_SYSTEM); + struct device_node *np; + u32 reset_type = DBCR0_RST_SYSTEM; + const u32 *prop; + + np = of_find_node_by_type(NULL, "cpu"); + if (np) { + prop = of_get_property(np, "reset-type", NULL); + if (prop) + reset_type = prop[0] << 28; + } + + mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | reset_type); + while (1) ; /* Just in case the reset doesn't work */ } -- 1.7.1 ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev