[PATCH 6/7] pm: at91: add achieve the mpddrc peripheral ID and the DDR clock ID support
Yang, Wenyou
Wenyou.Yang at atmel.com
Mon Jan 26 21:24:51 PST 2015
Hi Mark,
Thank you for your review.
> -----Original Message-----
> From: Mark Rutland [mailto:mark.rutland at arm.com]
> Sent: Monday, January 26, 2015 7:50 PM
> To: Yang, Wenyou
> Cc: Ferre, Nicolas; linux at arm.linux.org.uk; sylvain.rochet at finsecur.com; Vilchez,
> Patrice; linux-kernel at vger.kernel.org; alexandre.belloni at free-electrons.com;
> peda at axentia.se; linux-arm-kernel at lists.infradead.org
> Subject: Re: [PATCH 6/7] pm: at91: add achieve the mpddrc peripheral ID and the
> DDR clock ID support
>
> On Mon, Jan 26, 2015 at 10:08:16AM +0000, Wenyou Yang wrote:
> > The patch achieves the mpddr controller peripheral ID and the DDR
> > clock ID from the dts file.
> >
> > They will be used in the future to disable the mpddr controller'c
> > clock the and DDR clock to decrease the power consumption during suspending.
> >
> > Signed-off-by: Wenyou Yang <wenyou.yang at atmel.com>
> > ---
> > arch/arm/mach-at91/generic.h | 2 ++
> > arch/arm/mach-at91/setup.c | 24 ++++++++++++++++++++++++
> > 2 files changed, 26 insertions(+)
> >
> > diff --git a/arch/arm/mach-at91/generic.h
> > b/arch/arm/mach-at91/generic.h index 41796bf..3c72a3e 100644
> > --- a/arch/arm/mach-at91/generic.h
> > +++ b/arch/arm/mach-at91/generic.h
> > @@ -47,6 +47,8 @@ void __init at91_sam9x5_pm_init(void) { } struct
> > at91_pm_struct {
> > unsigned long uhp_udp_mask;
> > int memctrl;
> > + u32 mpddrc_id[2];
> > + u32 ddrck_id;
> > };
> >
> > #endif /* _AT91_GENERIC_H */
> > diff --git a/arch/arm/mach-at91/setup.c b/arch/arm/mach-at91/setup.c
> > index 7924663..a306f95 100644
> > --- a/arch/arm/mach-at91/setup.c
> > +++ b/arch/arm/mach-at91/setup.c
> > @@ -363,6 +363,27 @@ void __init at91_ioremap_matrix(u32 base_addr)
> > panic(pr_fmt("Impossible to ioremap at91_matrix_base\n")); }
> >
> > +static u32 at91_of_get_ddr_id(struct device_node *np, char *name) {
> > + struct of_phandle_args clkspec;
> > + u32 id;
> > + int index;
> > + int rc;
> > +
> > + index = of_property_match_string(np, "clock-names", name);
> > + rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
> &clkspec);
> > + if (rc)
> > + return 0;
> > +
> > + rc = of_property_read_u32(clkspec.np, "reg", &id);
> > + if (rc)
> > + return 0;
> > +
> > + of_node_put(clkspec.np);
> > +
> > + return id;
> > +}
>
> This doesn't look right to me. This assumes the format of the clock provider node,
> which invalidates the point of having the abstraction in the first place.
>
> > +
> > struct at91_ramc_of_data {
> > u8 ramc_type;
> > };
> > @@ -400,6 +421,9 @@ static void at91_dt_ramc(void)
> > of_data = of_id->data;
> > at91_pm_data.memctrl = of_data->ramc_type;
> >
> > + at91_pm_data.mpddrc_id[idx] = at91_of_get_ddr_id(np, "mpddr");
> > + at91_pm_data.ddrck_id = at91_of_get_ddr_id(np, "ddrck");
> > +
>
> Why do you need these here?
>
> Surely the logic for poking any clocks should live in the relevant clock controller
> drivers?
Thank for your suggestion.
I thought that it is reasonable to get the DDR controller's peripheral id from the DDR device node.
Anyway, let me think over how to do it.
>
> Mark.
Best Regards,
Wenyou Yang
More information about the linux-arm-kernel
mailing list