diff options
Diffstat (limited to 'drivers/clk/meson/clk-pll.c')
-rw-r--r-- | drivers/clk/meson/clk-pll.c | 69 |
1 files changed, 46 insertions, 23 deletions
diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c index 348a866f09eb..f5b5b3fabe3c 100644 --- a/drivers/clk/meson/clk-pll.c +++ b/drivers/clk/meson/clk-pll.c @@ -45,7 +45,7 @@ meson_clk_pll_data(struct clk_regmap *clk) } static unsigned long __pll_params_to_rate(unsigned long parent_rate, - const struct pll_rate_table *pllt, + const struct pll_params_table *pllt, u16 frac, struct meson_clk_pll_data *pll) { @@ -66,7 +66,7 @@ static unsigned long meson_clk_pll_recalc_rate(struct clk_hw *hw, { struct clk_regmap *clk = to_clk_regmap(hw); struct meson_clk_pll_data *pll = meson_clk_pll_data(clk); - struct pll_rate_table pllt; + struct pll_params_table pllt; u16 frac; pllt.n = meson_parm_read(clk->map, &pll->n); @@ -81,7 +81,7 @@ static unsigned long meson_clk_pll_recalc_rate(struct clk_hw *hw, static u16 __pll_params_with_frac(unsigned long rate, unsigned long parent_rate, - const struct pll_rate_table *pllt, + const struct pll_params_table *pllt, struct meson_clk_pll_data *pll) { u16 frac_max = (1 << pll->frac.width); @@ -97,29 +97,50 @@ static u16 __pll_params_with_frac(unsigned long rate, return min((u16)val, (u16)(frac_max - 1)); } -static const struct pll_rate_table * +static bool meson_clk_pll_is_better(unsigned long rate, + unsigned long best, + unsigned long now, + struct meson_clk_pll_data *pll) +{ + if (!(pll->flags & CLK_MESON_PLL_ROUND_CLOSEST) || + MESON_PARM_APPLICABLE(&pll->frac)) { + /* Round down */ + if (now < rate && best < now) + return true; + } else { + /* Round Closest */ + if (abs(now - rate) < abs(best - rate)) + return true; + } + + return false; +} + +static const struct pll_params_table * meson_clk_get_pll_settings(unsigned long rate, + unsigned long parent_rate, struct meson_clk_pll_data *pll) { - const struct pll_rate_table *table = pll->table; - unsigned int i = 0; + const struct pll_params_table *table = pll->table; + unsigned long best = 0, now = 0; + unsigned int i, best_i = 0; if (!table) return NULL; - /* Find the first table element exceeding rate */ - while (table[i].rate && table[i].rate <= rate) - i++; + for (i = 0; table[i].n; i++) { + now = __pll_params_to_rate(parent_rate, &table[i], 0, pll); - if (i != 0) { - if (MESON_PARM_APPLICABLE(&pll->frac) || - !(pll->flags & CLK_MESON_PLL_ROUND_CLOSEST) || - (abs(rate - table[i - 1].rate) < - abs(rate - table[i].rate))) - i--; + /* If we get an exact match, don't bother any further */ + if (now == rate) { + return &table[i]; + } else if (meson_clk_pll_is_better(rate, best, now, pll)) { + best = now; + best_i = i; + } } - return (struct pll_rate_table *)&table[i]; + return (struct pll_params_table *)&table[best_i]; } static long meson_clk_pll_round_rate(struct clk_hw *hw, unsigned long rate, @@ -127,16 +148,18 @@ static long meson_clk_pll_round_rate(struct clk_hw *hw, unsigned long rate, { struct clk_regmap *clk = to_clk_regmap(hw); struct meson_clk_pll_data *pll = meson_clk_pll_data(clk); - const struct pll_rate_table *pllt = - meson_clk_get_pll_settings(rate, pll); + const struct pll_params_table *pllt = + meson_clk_get_pll_settings(rate, *parent_rate, pll); + unsigned long round; u16 frac; if (!pllt) return meson_clk_pll_recalc_rate(hw, *parent_rate); - if (!MESON_PARM_APPLICABLE(&pll->frac) - || rate == pllt->rate) - return pllt->rate; + round = __pll_params_to_rate(*parent_rate, pllt, 0, pll); + + if (!MESON_PARM_APPLICABLE(&pll->frac) || rate == round) + return round; /* * The rate provided by the setting is not an exact match, let's @@ -214,7 +237,7 @@ static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate, { struct clk_regmap *clk = to_clk_regmap(hw); struct meson_clk_pll_data *pll = meson_clk_pll_data(clk); - const struct pll_rate_table *pllt; + const struct pll_params_table *pllt; unsigned int enabled; unsigned long old_rate; u16 frac = 0; @@ -224,7 +247,7 @@ static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate, old_rate = rate; - pllt = meson_clk_get_pll_settings(rate, pll); + pllt = meson_clk_get_pll_settings(rate, parent_rate, pll); if (!pllt) return -EINVAL; |