| Message ID | 20190228135246.31714-3-horms+renesas@verge.net.au (mailing list archive) |
|---|---|
| State | Under Review |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
| Series | clk: renesas: rcar-gen3: Add ZG support for E3, D3 and RZ/G2E | expand |
Hi Simon, On Thu, Feb 28, 2019 at 2:52 PM Simon Horman <horms+renesas@verge.net.au> wrote: > Adds support for R-Car E3 (r8a77990) ZG clock. > > Signed-off-by: Simon Horman <horms+renesas@verge.net.au> > --- > Tested on Ebisu to the extent that the clock rate is 600MHz on boot > --- > drivers/clk/renesas/r8a77990-cpg-mssr.c | 2 ++ > drivers/clk/renesas/rcar-gen3-cpg.c | 1 - > drivers/clk/renesas/rcar-gen3-cpg.h | 1 + > 3 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/clk/renesas/r8a77990-cpg-mssr.c b/drivers/clk/renesas/r8a77990-cpg-mssr.c > index 0e475dcb68b9..d0d29fc942ff 100644 > --- a/drivers/clk/renesas/r8a77990-cpg-mssr.c > +++ b/drivers/clk/renesas/r8a77990-cpg-mssr.c > @@ -83,6 +83,8 @@ static const struct cpg_core_clk r8a77990_core_clks[] __initconst = { > DEF_FIXED("za8", R8A77990_CLK_ZA8, CLK_PLL0D8, 1, 1), > DEF_GEN3_Z("z2", R8A77990_CLK_Z2, CLK_TYPE_GEN3_Z, CLK_PLL0, > 4, CPG_FRQCRC, 8), > + DEF_GEN3_Z("zg", R8A77990_CLK_ZG, CLK_TYPE_GEN3_Z, CLK_PLL0, > + 8, CPG_FRQCRB, 24), While this approach may be correct for R-Car H3, M3-W, and M3-N, this is not correct for R-Car E3, due to the presence of Spread Spectrum Clock Generator support: - When SCCG is enabled (MD12=1), the parent clock is either S0 or S1, with only 2 or 3 (out of 32) supported dividers, - When SCCG is disabled (MD12=0), the parent clock is PLL0, with only 2 (out of 32) supported dividers. So I'm afraid the ZG clock on SCCG-capable SoCs needs its own very special clock type. This applies also to R-Car D3 and RZ/G2E. Gr{oetje,eeting}s, Geert
On Fri, Mar 01, 2019 at 01:52:50PM +0100, Geert Uytterhoeven wrote: > Hi Simon, > > On Thu, Feb 28, 2019 at 2:52 PM Simon Horman <horms+renesas@verge.net.au> wrote: > > Adds support for R-Car E3 (r8a77990) ZG clock. > > > > Signed-off-by: Simon Horman <horms+renesas@verge.net.au> > > --- > > Tested on Ebisu to the extent that the clock rate is 600MHz on boot > > --- > > drivers/clk/renesas/r8a77990-cpg-mssr.c | 2 ++ > > drivers/clk/renesas/rcar-gen3-cpg.c | 1 - > > drivers/clk/renesas/rcar-gen3-cpg.h | 1 + > > 3 files changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/clk/renesas/r8a77990-cpg-mssr.c b/drivers/clk/renesas/r8a77990-cpg-mssr.c > > index 0e475dcb68b9..d0d29fc942ff 100644 > > --- a/drivers/clk/renesas/r8a77990-cpg-mssr.c > > +++ b/drivers/clk/renesas/r8a77990-cpg-mssr.c > > @@ -83,6 +83,8 @@ static const struct cpg_core_clk r8a77990_core_clks[] __initconst = { > > DEF_FIXED("za8", R8A77990_CLK_ZA8, CLK_PLL0D8, 1, 1), > > DEF_GEN3_Z("z2", R8A77990_CLK_Z2, CLK_TYPE_GEN3_Z, CLK_PLL0, > > 4, CPG_FRQCRC, 8), > > + DEF_GEN3_Z("zg", R8A77990_CLK_ZG, CLK_TYPE_GEN3_Z, CLK_PLL0, > > + 8, CPG_FRQCRB, 24), > > While this approach may be correct for R-Car H3, M3-W, and M3-N, this is > not correct for R-Car E3, due to the presence of Spread Spectrum Clock > Generator support: > - When SCCG is enabled (MD12=1), the parent clock is either S0 or S1, > with only 2 or 3 (out of 32) supported dividers, > - When SCCG is disabled (MD12=0), the parent clock is PLL0, with only > 2 (out of 32) supported dividers. > > So I'm afraid the ZG clock on SCCG-capable SoCs needs its own very special > clock type. Thanks for pointing this out, I'll investigate further. > > This applies also to R-Car D3 and RZ/G2E. > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds >
Hi Simon, On Mon, Mar 4, 2019 at 10:45 AM Simon Horman <horms@verge.net.au> wrote: > On Fri, Mar 01, 2019 at 01:52:50PM +0100, Geert Uytterhoeven wrote: > > On Thu, Feb 28, 2019 at 2:52 PM Simon Horman <horms+renesas@verge.net.au> wrote: > > > Adds support for R-Car E3 (r8a77990) ZG clock. > > > > > > Signed-off-by: Simon Horman <horms+renesas@verge.net.au> > > > --- > > > Tested on Ebisu to the extent that the clock rate is 600MHz on boot > > > --- > > > drivers/clk/renesas/r8a77990-cpg-mssr.c | 2 ++ > > > drivers/clk/renesas/rcar-gen3-cpg.c | 1 - > > > drivers/clk/renesas/rcar-gen3-cpg.h | 1 + > > > 3 files changed, 3 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/clk/renesas/r8a77990-cpg-mssr.c b/drivers/clk/renesas/r8a77990-cpg-mssr.c > > > index 0e475dcb68b9..d0d29fc942ff 100644 > > > --- a/drivers/clk/renesas/r8a77990-cpg-mssr.c > > > +++ b/drivers/clk/renesas/r8a77990-cpg-mssr.c > > > @@ -83,6 +83,8 @@ static const struct cpg_core_clk r8a77990_core_clks[] __initconst = { > > > DEF_FIXED("za8", R8A77990_CLK_ZA8, CLK_PLL0D8, 1, 1), > > > DEF_GEN3_Z("z2", R8A77990_CLK_Z2, CLK_TYPE_GEN3_Z, CLK_PLL0, > > > 4, CPG_FRQCRC, 8), > > > + DEF_GEN3_Z("zg", R8A77990_CLK_ZG, CLK_TYPE_GEN3_Z, CLK_PLL0, > > > + 8, CPG_FRQCRB, 24), > > > > While this approach may be correct for R-Car H3, M3-W, and M3-N, this is > > not correct for R-Car E3, due to the presence of Spread Spectrum Clock > > Generator support: > > - When SCCG is enabled (MD12=1), the parent clock is either S0 or S1, > > with only 2 or 3 (out of 32) supported dividers, > > - When SCCG is disabled (MD12=0), the parent clock is PLL0, with only > > 2 (out of 32) supported dividers. > > > > So I'm afraid the ZG clock on SCCG-capable SoCs needs its own very special > > clock type. > > Thanks for pointing this out, I'll investigate further. Given MD12 is sampled a reset time, there's no need to handle both cases at runtime. I.e. if MD12=0, you can register a simple clock with one parent and two dividers. If MD12=1, you can register a more complex custom clock with two parents and 2 or 3 dividers. Gr{oetje,eeting}s, Geert
diff --git a/drivers/clk/renesas/r8a77990-cpg-mssr.c b/drivers/clk/renesas/r8a77990-cpg-mssr.c index 0e475dcb68b9..d0d29fc942ff 100644 --- a/drivers/clk/renesas/r8a77990-cpg-mssr.c +++ b/drivers/clk/renesas/r8a77990-cpg-mssr.c @@ -83,6 +83,8 @@ static const struct cpg_core_clk r8a77990_core_clks[] __initconst = { DEF_FIXED("za8", R8A77990_CLK_ZA8, CLK_PLL0D8, 1, 1), DEF_GEN3_Z("z2", R8A77990_CLK_Z2, CLK_TYPE_GEN3_Z, CLK_PLL0, 4, CPG_FRQCRC, 8), + DEF_GEN3_Z("zg", R8A77990_CLK_ZG, CLK_TYPE_GEN3_Z, CLK_PLL0, + 8, CPG_FRQCRB, 24), DEF_FIXED("ztr", R8A77990_CLK_ZTR, CLK_PLL1, 6, 1), DEF_FIXED("zt", R8A77990_CLK_ZT, CLK_PLL1, 4, 1), DEF_FIXED("zx", R8A77990_CLK_ZX, CLK_PLL1, 3, 1), diff --git a/drivers/clk/renesas/rcar-gen3-cpg.c b/drivers/clk/renesas/rcar-gen3-cpg.c index 14a82c51682e..0d0e698442e2 100644 --- a/drivers/clk/renesas/rcar-gen3-cpg.c +++ b/drivers/clk/renesas/rcar-gen3-cpg.c @@ -70,7 +70,6 @@ static void cpg_simple_notifier_register(struct raw_notifier_head *notifiers, * rate - rate is adjustable. clk->rate = (parent->rate * mult / 32 ) / 2 * parent - fixed parent. No clk_set_parent support */ -#define CPG_FRQCRB 0x00000004 #define CPG_FRQCRB_KICK BIT(31) struct cpg_z_clk { diff --git a/drivers/clk/renesas/rcar-gen3-cpg.h b/drivers/clk/renesas/rcar-gen3-cpg.h index 02bf3785263c..9525df8a835c 100644 --- a/drivers/clk/renesas/rcar-gen3-cpg.h +++ b/drivers/clk/renesas/rcar-gen3-cpg.h @@ -68,6 +68,7 @@ struct rcar_gen3_cpg_pll_config { u8 osc_prediv; }; +#define CPG_FRQCRB 0x004 #define CPG_FRQCRC 0x0e0 #define CPG_RCKCR 0x240
Adds support for R-Car E3 (r8a77990) ZG clock. Signed-off-by: Simon Horman <horms+renesas@verge.net.au> --- Tested on Ebisu to the extent that the clock rate is 600MHz on boot --- drivers/clk/renesas/r8a77990-cpg-mssr.c | 2 ++ drivers/clk/renesas/rcar-gen3-cpg.c | 1 - drivers/clk/renesas/rcar-gen3-cpg.h | 1 + 3 files changed, 3 insertions(+), 1 deletion(-)