[PATCH v2 7/9] clk: meson: fix rate calculation of plls with a fractional part

From: Jerome Brunet
Date: Fri Jan 19 2018 - 10:56:33 EST


The rate of the parent should not be multiplied by 2 when the pll has a
fractional part. This is making the rate calculation of the gxl_hdmi_pll
wrong (and others as well). This multiplication is specific
to the hdmi_pll of gxbb and is most likely due to a multiplier sitting
in front of this particular pll.

Add a fixed factor clock in front on the gxbb pll and remove this constant
from the calculation to fix the problem

Fixes: 4a47295144dd ("clk: meson: fractional pll support")
Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
---
drivers/clk/meson/clk-pll.c | 1 -
drivers/clk/meson/gxbb.c | 14 +++++++++++++-
drivers/clk/meson/gxbb.h | 3 ++-
3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c
index 1595f02f610f..218c769c6d50 100644
--- a/drivers/clk/meson/clk-pll.c
+++ b/drivers/clk/meson/clk-pll.c
@@ -88,7 +88,6 @@ static unsigned long meson_clk_pll_recalc_rate(struct clk_hw *hw,
frac = PARM_GET(p->width, p->shift, reg);

rate += mul_u64_u32_shr(parent_rate, frac, p->width);
- rate *= 2;
}

return div_u64(rate, n) >> od >> od2 >> od3;
diff --git a/drivers/clk/meson/gxbb.c b/drivers/clk/meson/gxbb.c
index f74ed52e2673..b773be1033f8 100644
--- a/drivers/clk/meson/gxbb.c
+++ b/drivers/clk/meson/gxbb.c
@@ -212,6 +212,17 @@ static struct meson_clk_pll gxbb_fixed_pll = {
},
};

+static struct clk_fixed_factor gxbb_hdmi_pll_pre_mult = {
+ .mult = 2,
+ .div = 1,
+ .hw.init = &(struct clk_init_data){
+ .name = "hdmi_pll_pre_mult",
+ .ops = &clk_fixed_factor_ops,
+ .parent_names = (const char *[]){ "xtal" },
+ .num_parents = 1,
+ },
+};
+
static struct meson_clk_pll gxbb_hdmi_pll = {
.m = {
.reg_off = HHI_HDMI_PLL_CNTL,
@@ -247,7 +258,7 @@ static struct meson_clk_pll gxbb_hdmi_pll = {
.hw.init = &(struct clk_init_data){
.name = "hdmi_pll",
.ops = &meson_clk_pll_ro_ops,
- .parent_names = (const char *[]){ "xtal" },
+ .parent_names = (const char *[]){ "hdmi_pll_pre_mult" },
.num_parents = 1,
.flags = CLK_GET_RATE_NOCACHE,
},
@@ -1558,6 +1569,7 @@ static struct clk_hw_onecell_data gxbb_hw_onecell_data = {
[CLKID_VAPB_1] = &gxbb_vapb_1.hw,
[CLKID_VAPB_SEL] = &gxbb_vapb_sel.hw,
[CLKID_VAPB] = &gxbb_vapb.hw,
+ [CLKID_HDMI_PLL_PRE_MULT] = &gxbb_hdmi_pll_pre_mult.hw,
[NR_CLKS] = NULL,
},
.num = NR_CLKS,
diff --git a/drivers/clk/meson/gxbb.h b/drivers/clk/meson/gxbb.h
index aee6fbba2004..42573b28a137 100644
--- a/drivers/clk/meson/gxbb.h
+++ b/drivers/clk/meson/gxbb.h
@@ -194,8 +194,9 @@
#define CLKID_VPU_1_DIV 130
#define CLKID_VAPB_0_DIV 134
#define CLKID_VAPB_1_DIV 137
+#define CLKID_HDMI_PLL_PRE_MULT 141

-#define NR_CLKS 141
+#define NR_CLKS 142

/* include the CLKIDs that have been made part of the DT binding */
#include <dt-bindings/clock/gxbb-clkc.h>
--
2.14.3