Re: [PATCH 5/6] clk: rockchip: rk3036: fix and add node id for emac clock

Heiko Stübner
2016-03-11T11:15:33Z

Hi Caesar,

Am Freitag, 11. März 2016, 18:55:30 schrieb Caesar Wang:
> From: zhengxing <zhengxing@rock-chips.com>
>
> In the emac driver, we need to refer HCLK_MAC since there are
> only 3PLLs (APLL/GPLL/DPLL) on the rk3036, most clocks are under the
> GPLL, and it is unable to provide the accurate rate for mac_ref which
> need to 50MHz probability, we should let it under the DPLL and are
> able to set the freq which integer multiples of 50MHz, so we add these
> emac node for reference.
>
> Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>
> Signed-off-by: Caesar Wang <wxt@rock-chips.com>

I think I mentioned it somewhere before, but I'd like to do this
differently, like in [0].

That should work in a similar way and at least in my tests the reported
clock rate seems to be correct. As I said as well I haven't been able to
make the emac detect a link on my kylin boards, so it would be cool
if you could test if this different approach works in practice as well.

Thanks
Heiko

------ 8< ---------
From e83a8b19dbf95c40d2c908727c342fbc6b167ea1 Mon Sep 17 00:00:00 2001
From: Heiko Stuebner <heiko@sntech.de>
Date: Fri, 19 Feb 2016 21:31:43 +0100
Subject: [PATCH] clk: rockchip: associate SCLK_MAC_PLL and disable reparenting
on rk3036

The emac needs constant and very specific rate but the possible PLL-sources
are very limited, so we expect the PLL source to be set manually on per
board and don't want it to get changed in an automatic way later.
So add the necessary clock-id and disable reparenting on set_rate calls.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
drivers/clk/rockchip/clk-rk3036.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/rockchip/clk-rk3036.c b/drivers/clk/rockchip/clk-rk3036.c
index 3c742bf..0084c57 100644
--- a/drivers/clk/rockchip/clk-rk3036.c
+++ b/drivers/clk/rockchip/clk-rk3036.c
@@ -348,7 +348,7 @@ static struct rockchip_clk_branch rk3036_clk_branches[] __initdata = {
RK2928_CLKSEL_CON(16), 0, 2, MFLAGS, 2, 5, DFLAGS,
RK2928_CLKGATE_CON(10), 5, GFLAGS),

- COMPOSITE_NOGATE(0, "mac_pll_src", mux_pll_src_3plls_p, 0,
+ COMPOSITE_NOGATE(SCLK_MACPLL, "mac_pll_src", mux_pll_src_3plls_p, CLK_SET_RATE_NO_REPARENT,
RK2928_CLKSEL_CON(21), 0, 2, MFLAGS, 4, 5, DFLAGS),
MUX(SCLK_MACREF, "mac_clk_ref", mux_mac_p, CLK_SET_RATE_PARENT,
RK2928_CLKSEL_CON(21), 3, 1, MFLAGS),

------ 8< ---------

[0] https://github.com/mmind/linux-rockchip/commit/e83a8b19dbf95c40d2c908727c342fbc6b167ea1

> ---
>
> drivers/clk/rockchip/clk-rk3036.c | 9 ++++++---
> include/dt-bindings/clock/rk3036-cru.h | 2 ++
> 2 files changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clk/rockchip/clk-rk3036.c
> b/drivers/clk/rockchip/clk-rk3036.c index 0703c8f..27c35fa 100644
> --- a/drivers/clk/rockchip/clk-rk3036.c
> +++ b/drivers/clk/rockchip/clk-rk3036.c
> @@ -348,8 +348,11 @@ static struct rockchip_clk_branch rk3036_clk_branches[]
> __initdata = { RK2928_CLKSEL_CON(16), 0, 2, MFLAGS, 2, 5, DFLAGS,
> RK2928_CLKGATE_CON(10), 5, GFLAGS),
>
> - COMPOSITE_NOGATE(0, "mac_pll_src", mux_pll_src_3plls_p, 0,
> - RK2928_CLKSEL_CON(21), 0, 2, MFLAGS, 9, 5, DFLAGS),
> + MUX(SCLK_MACPLL, "mac_pll_pre", mux_pll_src_3plls_p, 0,
> + RK2928_CLKSEL_CON(21), 0, 2, MFLAGS),
> + DIV(0, "mac_pll_src", "mac_pll_pre", 0,
> + RK2928_CLKSEL_CON(21), 9, 5, DFLAGS),
> +
> MUX(SCLK_MACREF, "mac_clk_ref", mux_mac_p, CLK_SET_RATE_PARENT,
> RK2928_CLKSEL_CON(21), 3, 1, MFLAGS),
>
> @@ -408,7 +411,7 @@ static struct rockchip_clk_branch rk3036_clk_branches[]
> __initdata = { GATE(HCLK_OTG1, "hclk_otg1", "hclk_peri", CLK_IGNORE_UNUSED,
> RK2928_CLKGATE_CON(7), 3, GFLAGS), GATE(HCLK_I2S, "hclk_i2s", "hclk_peri",
> 0, RK2928_CLKGATE_CON(7), 2, GFLAGS), GATE(0, "hclk_sfc", "hclk_peri",
> CLK_IGNORE_UNUSED, RK2928_CLKGATE_CON(3), 14, GFLAGS), - GATE(0,
> "hclk_mac", "hclk_peri", CLK_IGNORE_UNUSED, RK2928_CLKGATE_CON(3), 15,
> GFLAGS), + GATE(HCLK_MAC, "hclk_mac", "hclk_peri", 0,
> RK2928_CLKGATE_CON(3), 5, GFLAGS),
>
> /* pclk_peri gates */
> GATE(0, "pclk_peri_matrix", "pclk_peri", CLK_IGNORE_UNUSED,
> RK2928_CLKGATE_CON(4), 1, GFLAGS), diff --git
> a/include/dt-bindings/clock/rk3036-cru.h
> b/include/dt-bindings/clock/rk3036-cru.h index ebc7a7b..de44109 100644
> --- a/include/dt-bindings/clock/rk3036-cru.h
> +++ b/include/dt-bindings/clock/rk3036-cru.h
> @@ -54,6 +54,7 @@
> #define SCLK_PVTM_VIDEO 125
> #define SCLK_MAC 151
> #define SCLK_MACREF 152
> +#define SCLK_MACPLL 153
> #define SCLK_SFC 160
>
> /* aclk gates */
> @@ -92,6 +93,7 @@
> #define HCLK_SDMMC 456
> #define HCLK_SDIO 457
> #define HCLK_EMMC 459
> +#define HCLK_MAC 460
> #define HCLK_I2S 462
> #define HCLK_LCDC 465
> #define HCLK_ROM 467