[PATCH v2 05/18] clk: at91: sam9x60-pll: check fcore against ranges
From: Claudiu Beznea <hidden>
Date: 2020-07-22 07:38:59
Also in:
linux-clk, lkml
Subsystem:
common clk framework, the rest · Maintainers:
Michael Turquette, Stephen Boyd, Linus Torvalds
According to datasheet the range of 600-1200MHz is for the
frequency generated by the fractional part of the PLL (namely
Fcorepllck according to datasheet). With this in mind the output
range of the PLL itself (fractional + div), taking into account
that the divider is 8 bits wide, is 600/256-1200Hz=2.3-1200MHz.
Fixes: a436c2a447e59 ("clk: at91: add sam9x60 PLL driver")
Signed-off-by: Claudiu Beznea <redacted>
---
drivers/clk/at91/clk-sam9x60-pll.c | 12 +++++++++++-
drivers/clk/at91/sam9x60.c | 2 +-
2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/at91/clk-sam9x60-pll.c b/drivers/clk/at91/clk-sam9x60-pll.c
index 4b7b6c435d4e..a933abebfbaf 100644
--- a/drivers/clk/at91/clk-sam9x60-pll.c
+++ b/drivers/clk/at91/clk-sam9x60-pll.c@@ -21,6 +21,9 @@ #define UPLL_DIV 2 #define PLL_MUL_MAX (FIELD_GET(PMC_PLL_CTRL1_MUL_MSK, UINT_MAX) + 1) +#define FCORE_MIN (600000000) +#define FCORE_MAX (1200000000) + #define PLL_MAX_ID 1 struct sam9x60_pll {
@@ -168,6 +171,7 @@ static long sam9x60_pll_get_best_div_mul(struct sam9x60_pll *pll, unsigned long bestdiv = 0; unsigned long bestmul = 0; unsigned long bestfrac = 0; + u64 fcore = 0; if (rate < characteristics->output[0].min || rate > characteristics->output[0].max)
@@ -212,6 +216,11 @@ static long sam9x60_pll_get_best_div_mul(struct sam9x60_pll *pll, remainder = rate - tmprate; } + fcore = parent_rate * (tmpmul + 1) + + ((u64)parent_rate * tmpfrac >> 22); + if (fcore < FCORE_MIN || fcore > FCORE_MAX) + continue; + /* * Compare the remainder with the best remainder found until * now and elect a new best multiplier/divider pair if the
@@ -231,7 +240,8 @@ static long sam9x60_pll_get_best_div_mul(struct sam9x60_pll *pll, } /* Check if bestrate is a valid output rate */ - if (bestrate < characteristics->output[0].min || + if (fcore < FCORE_MIN || fcore > FCORE_MAX || + bestrate < characteristics->output[0].min || bestrate > characteristics->output[0].max) return -ERANGE;
diff --git a/drivers/clk/at91/sam9x60.c b/drivers/clk/at91/sam9x60.c
index 3e20aa68259f..633891b98d43 100644
--- a/drivers/clk/at91/sam9x60.c
+++ b/drivers/clk/at91/sam9x60.c@@ -22,7 +22,7 @@ static const struct clk_master_layout sam9x60_master_layout = { }; static const struct clk_range plla_outputs[] = { - { .min = 300000000, .max = 600000000 }, + { .min = 2343750, .max = 1200000000 }, }; static const struct clk_pll_characteristics plla_characteristics = {
--
2.7.4
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