From: Martin Blumenstingl martin.blumenstingl@googlemail.com
[ Upstream commit a29ae8600d50ece1856b062a39ed296b8b952259 ]
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 Signed-off-by: Jerome Brunet jbrunet@baylibre.com Link: https://lore.kernel.org/r/20200501215717.735393-1-martin.blumenstingl@google... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/clk/meson/meson8b.c | 9 +++++++++ drivers/clk/meson/meson8b.h | 4 ++++ 2 files changed, 13 insertions(+)
diff --git a/drivers/clk/meson/meson8b.c b/drivers/clk/meson/meson8b.c index 4f9b79ed79d7d..082178a0f41a3 100644 --- a/drivers/clk/meson/meson8b.c +++ b/drivers/clk/meson/meson8b.c @@ -1910,6 +1910,13 @@ 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 */ }, @@ -1943,6 +1950,8 @@ 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 c889fbeec30f0..c91fb07fcb657 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 */