Re: [PATCH] clk: meson: meson8b: Don't rely on u-boot to init all GP_PLL registers
From: Jerome Brunet <jbrunet@baylibre.com>
Date: 2020-05-02 00:01:59
Also in:
linux-amlogic, linux-clk, lkml
On Fri 01 May 2020 at 23:57, Martin Blumenstingl [off-list ref] wrote:
Not all u-boot versions initialize the HHI_GP_PLL_CNTL[2-5] registers.
In that case all HHI_GPLL_PLL_CNTL[1-5] registers are 0x0 and when
booting Linux the PLL fails to lock.
The initialization sequence from u-boot is:
- put the PLL into reset
- write 0x59C88000 to HHI_GP_PLL_CNTL2
- write 0xCA463823 to HHI_GP_PLL_CNTL3
- write 0x0286A027 to HHI_GP_PLL_CNTL4
- write 0x00003000 to HHI_GP_PLL_CNTL5
- set M, N, OD and the enable bit
- take the PLL out of reset
- check if it has locked
- disable the PLL
In Linux we already initialize M, N, OD, the enable and the reset bits.
Also the HHI_GP_PLL_CNTL[2-5] registers with these magic values (the
exact meaning is unknown) so the PLL can lock when the vendor u-boot did
not initialize these registers yet.
Fixes: b882964b376f21 ("clk: meson: meson8b: add support for the GP_PLL clock on Meson8m2")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
Jerome, this one is also not critical because we don't enable the VPU
yet. So I based this on commit 16afd70af5b21b ("clk: meson: meson8b:
Make the CCF use the glitch-free VPU mux").
drivers/clk/meson/meson8b.c | 9 +++++++++
drivers/clk/meson/meson8b.h | 4 ++++
2 files changed, 13 insertions(+)Applied, Thx
quoted hunk ↗ jump to hunk
diff --git a/drivers/clk/meson/meson8b.c b/drivers/clk/meson/meson8b.c index 811af1c11456..edc09d050ecf 100644 --- a/drivers/clk/meson/meson8b.c +++ b/drivers/clk/meson/meson8b.c@@ -1918,6 +1918,13 @@ static struct clk_regmap meson8b_mali = { }, }; +static const struct reg_sequence meson8m2_gp_pll_init_regs[] = { + { .reg = HHI_GP_PLL_CNTL2, .def = 0x59c88000 }, + { .reg = HHI_GP_PLL_CNTL3, .def = 0xca463823 }, + { .reg = HHI_GP_PLL_CNTL4, .def = 0x0286a027 }, + { .reg = HHI_GP_PLL_CNTL5, .def = 0x00003000 }, +}; + static const struct pll_params_table meson8m2_gp_pll_params_table[] = { PLL_PARAMS(182, 3), { /* sentinel */ },@@ -1951,6 +1958,8 @@ static struct clk_regmap meson8m2_gp_pll_dco = { .width = 1, }, .table = meson8m2_gp_pll_params_table, + .init_regs = meson8m2_gp_pll_init_regs, + .init_count = ARRAY_SIZE(meson8m2_gp_pll_init_regs), }, .hw.init = &(struct clk_init_data){ .name = "gp_pll_dco",diff --git a/drivers/clk/meson/meson8b.h b/drivers/clk/meson/meson8b.h index 94ce3ef0c1d5..cd38ae2a9cb5 100644 --- a/drivers/clk/meson/meson8b.h +++ b/drivers/clk/meson/meson8b.h@@ -20,6 +20,10 @@ * [0] http://dn.odroid.com/S805/Datasheet/S805_Datasheet%20V0.8%2020150126.pdf */ #define HHI_GP_PLL_CNTL 0x40 /* 0x10 offset in data sheet */ +#define HHI_GP_PLL_CNTL2 0x44 /* 0x11 offset in data sheet */ +#define HHI_GP_PLL_CNTL3 0x48 /* 0x12 offset in data sheet */ +#define HHI_GP_PLL_CNTL4 0x4C /* 0x13 offset in data sheet */ +#define HHI_GP_PLL_CNTL5 0x50 /* 0x14 offset in data sheet */ #define HHI_VIID_CLK_DIV 0x128 /* 0x4a offset in data sheet */ #define HHI_VIID_CLK_CNTL 0x12c /* 0x4b offset in data sheet */ #define HHI_GCLK_MPEG0 0x140 /* 0x50 offset in data sheet */
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