| Message ID | 1588933426-3952-2-git-send-email-amittomer25@gmail.com |
|---|---|
| State | Superseded |
| Delegated to: | Tom Rini |
| Headers | show |
| Series | Calculate SDRAM size for Actions OWL SoCs | expand |
Hi Amit, On Fri, May 08, 2020 at 03:53:45PM +0530, Amit Singh Tomar wrote: > Calculate the SDRAM size from DDR capacity register registers instead > of using hard-coded value. This is quite useful to get correct size > on differnt boards based on Actions OWL family of SoCs (S700 and S900). > > There is no documentation available that talks about DDR registers, and > this is very much taken from vendor source. > > This commit lets Linux boot on Cubieboard7-lite(based on S700). > > Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com> > --- > Changes since v1: > * added support for S900 > * updated the commit message to reflect common OWL > support. > --- > arch/arm/mach-owl/soc.c | 27 ++++++++++++++++++++++++++- > 1 file changed, 26 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/mach-owl/soc.c b/arch/arm/mach-owl/soc.c > index 409cbd319f20..2ae357e3672a 100644 > --- a/arch/arm/mach-owl/soc.c > +++ b/arch/arm/mach-owl/soc.c > @@ -13,15 +13,40 @@ > #include <asm/mach-types.h> > #include <asm/psci.h> > > +#define DMM_INTERLEAVE_BASE (0xe0290020) > +#define DMM_INTERLEAVE_PER_CH_CFG (DMM_INTERLEAVE_BASE + 0x08) > +#define DMM_MASTER_READ_TO (DMM_INTERLEAVE_BASE + 0x48) > + > DECLARE_GLOBAL_DATA_PTR; > > +unsigned int get_owl_ram_size(void) > +{ > + __maybe_unused unsigned int val, cap, channel, channel_num; > + > + /* ddr capacity register initialized by ddr driver > + * in early bootloader > + */ > +#if defined(CONFIG_MACH_S700) > + val = (readl(DMM_INTERLEAVE_PER_CH_CFG) >> 8) & 0x7; > + cap = (val + 1) * 256; > +#elif defined(CONFIG_MACH_S900) > + chennel_num = (readl(DMM_INTERLEAVE_BASE) >> 24) & 0xf; > + channel = (ch_num >= 3) ? 1 : 0; > + val = (readl(DMM_MASTER_READ_TO)) & 0xf; > + cap = ((val + 1) << channel) * 256; This doesn't work on Bubblegum96. But poking into the vendor tree, I'm able to come up with below working code: val = (readl(DMM_INTERLEAVE_PER_CH_CFG) >> 8) & 0xf; cap = 64 * (1 << val); So, you can use this and remove other stuffs. Also this function should be named as owl_get_ddr_cap(). Thanks, Mani > +#endif > + > + return cap; > +} > + > /* > * dram_init - sets uboots idea of sdram size > */ > int dram_init(void) > { > - gd->ram_size = CONFIG_SYS_SDRAM_SIZE; > + gd->ram_size = get_owl_ram_size() * 1024 * 1024; > return 0; > + > } > > /* This is called after dram_init() so use get_ram_size result */ > -- > 2.7.4 >
Hi Mani, > > This doesn't work on Bubblegum96. But poking into the vendor tree, I'm able > to come up with below working code: > > val = (readl(DMM_INTERLEAVE_PER_CH_CFG) >> 8) & 0xf; > cap = 64 * (1 << val); > > So, you can use this and remove other stuffs. Also this function should be named > as owl_get_ddr_cap(). Thanks for pointing this out, and I just sent v3 as v2 didn't even compile for Bubblegum96. Would send the updated version that works on S900. Thanks Amit.
diff --git a/arch/arm/mach-owl/soc.c b/arch/arm/mach-owl/soc.c index 409cbd319f20..2ae357e3672a 100644 --- a/arch/arm/mach-owl/soc.c +++ b/arch/arm/mach-owl/soc.c @@ -13,15 +13,40 @@ #include <asm/mach-types.h> #include <asm/psci.h> +#define DMM_INTERLEAVE_BASE (0xe0290020) +#define DMM_INTERLEAVE_PER_CH_CFG (DMM_INTERLEAVE_BASE + 0x08) +#define DMM_MASTER_READ_TO (DMM_INTERLEAVE_BASE + 0x48) + DECLARE_GLOBAL_DATA_PTR; +unsigned int get_owl_ram_size(void) +{ + __maybe_unused unsigned int val, cap, channel, channel_num; + + /* ddr capacity register initialized by ddr driver + * in early bootloader + */ +#if defined(CONFIG_MACH_S700) + val = (readl(DMM_INTERLEAVE_PER_CH_CFG) >> 8) & 0x7; + cap = (val + 1) * 256; +#elif defined(CONFIG_MACH_S900) + chennel_num = (readl(DMM_INTERLEAVE_BASE) >> 24) & 0xf; + channel = (ch_num >= 3) ? 1 : 0; + val = (readl(DMM_MASTER_READ_TO)) & 0xf; + cap = ((val + 1) << channel) * 256; +#endif + + return cap; +} + /* * dram_init - sets uboots idea of sdram size */ int dram_init(void) { - gd->ram_size = CONFIG_SYS_SDRAM_SIZE; + gd->ram_size = get_owl_ram_size() * 1024 * 1024; return 0; + } /* This is called after dram_init() so use get_ram_size result */
Calculate the SDRAM size from DDR capacity register registers instead of using hard-coded value. This is quite useful to get correct size on differnt boards based on Actions OWL family of SoCs (S700 and S900). There is no documentation available that talks about DDR registers, and this is very much taken from vendor source. This commit lets Linux boot on Cubieboard7-lite(based on S700). Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com> --- Changes since v1: * added support for S900 * updated the commit message to reflect common OWL support. --- arch/arm/mach-owl/soc.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-)