diff options
| -rw-r--r-- | drivers/clk/meson/Makefile | 2 | ||||
| -rw-r--r-- | drivers/clk/meson/clkc-audio.h | 8 | ||||
| -rw-r--r-- | drivers/clk/meson/sclk-div.c | 243 |
3 files changed, 252 insertions, 1 deletions
diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile index 74ec070b0974..1574e3f0de5c 100644 --- a/drivers/clk/meson/Makefile +++ b/drivers/clk/meson/Makefile @@ -4,7 +4,7 @@ obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-audio-divider.o obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-phase.o -obj-$(CONFIG_COMMON_CLK_AMLOGIC_AUDIO) += clk-triphase.o +obj-$(CONFIG_COMMON_CLK_AMLOGIC_AUDIO) += clk-triphase.o sclk-div.o obj-$(CONFIG_COMMON_CLK_MESON_AO) += meson-aoclk.o obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o obj-$(CONFIG_COMMON_CLK_GXBB) += gxbb.o gxbb-aoclk.o gxbb-aoclk-32k.o diff --git a/drivers/clk/meson/clkc-audio.h b/drivers/clk/meson/clkc-audio.h index 286ff1201258..0a7c157ebf81 100644 --- a/drivers/clk/meson/clkc-audio.h +++ b/drivers/clk/meson/clkc-audio.h @@ -15,6 +15,14 @@ struct meson_clk_triphase_data { struct parm ph2; }; +struct meson_sclk_div_data { + struct parm div; + struct parm hi; + unsigned int cached_div; + struct clk_duty cached_duty; +}; + extern const struct clk_ops meson_clk_triphase_ops; +extern const struct clk_ops meson_sclk_div_ops; #endif /* __MESON_CLKC_AUDIO_H */ diff --git a/drivers/clk/meson/sclk-div.c b/drivers/clk/meson/sclk-div.c new file mode 100644 index 000000000000..bc64019b8eeb --- /dev/null +++ b/drivers/clk/meson/sclk-div.c @@ -0,0 +1,243 @@ +// SPDX-License-Identifier: (GPL-2.0 OR MIT) +/* + * Copyright (c) 2018 BayLibre, SAS. + * Author: Jerome Brunet <jbrunet@baylibre.com> + * + * Sample clock generator divider: + * This HW divider gates with value 0 but is otherwise a zero based divider: + * + * val >= 1 + * divider = val + 1 + * + * The duty cycle may also be set for the LR clock variant. The duty cycle + * ratio is: + * + * hi = [0 - val] + * duty_cycle = (1 + hi) / (1 + val) + */ + +#include "clkc-audio.h" + +static inline struct meson_sclk_div_data * +meson_sclk_div_data(struct clk_regmap *clk) +{ + return (struct meson_sclk_div_data *)clk->data; +} + +static int sclk_div_maxval(struct meson_sclk_div_data *sclk) +{ + return (1 << sclk->div.width) - 1; +} + +static int sclk_div_maxdiv(struct meson_sclk_div_data *sclk) +{ + return sclk_div_maxval(sclk) + 1; +} + +static int sclk_div_getdiv(struct clk_hw *hw, unsigned long rate, + unsigned long prate, int maxdiv) +{ + int div = DIV_ROUND_CLOSEST_ULL((u64)prate, rate); + + return clamp(div, 2, maxdiv); +} + +static int sclk_div_bestdiv(struct clk_hw *hw, unsigned long rate, + unsigned long *prate, + struct meson_sclk_div_data *sclk) +{ + struct clk_hw *parent = clk_hw_get_parent(hw); + int bestdiv = 0, i; + unsigned long maxdiv, now, parent_now; + unsigned long best = 0, best_parent = 0; + + if (!rate) + rate = 1; + + maxdiv = sclk_div_maxdiv(sclk); + + if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) + return sclk_div_getdiv(hw, rate, *prate, maxdiv); + + /* + * The maximum divider we can use without overflowing + * unsigned long in rate * i below + */ + maxdiv = min(ULONG_MAX / rate, maxdiv); + + for (i = 2; i <= maxdiv; i++) { + /* + * It's the most ideal case if the requested rate can be + * divided from parent clock without needing to change + * parent rate, so return the divider immediately. + */ + if (rate * i == *prate) + return i; + + parent_now = clk_hw_round_rate(parent, rate * i); + now = DIV_ROUND_UP_ULL((u64)parent_now, i); + + if (abs(rate - now) < abs(rate - best)) { + bestdiv = i; + best = now; + best_parent = parent_now; + } + } + + if (!bestdiv) + bestdiv = sclk_div_maxdiv(sclk); + else + *prate = best_parent; + + return bestdiv; +} + +static long sclk_div_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + int div; + + div = sclk_div_bestdiv(hw, rate, prate, sclk); + + return DIV_ROUND_UP_ULL((u64)*prate, div); +} + +static void sclk_apply_ratio(struct clk_regmap *clk, + struct meson_sclk_div_data *sclk) +{ + unsigned int hi = DIV_ROUND_CLOSEST(sclk->cached_div * + sclk->cached_duty.num, + sclk->cached_duty.den); + + if (hi) + hi -= 1; + + meson_parm_write(clk->map, &sclk->hi, hi); +} + +static int sclk_div_set_duty_cycle(struct clk_hw *hw, + struct clk_duty *duty) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + + if (MESON_PARM_APPLICABLE(&sclk->hi)) { + memcpy(&sclk->cached_duty, duty, sizeof(*duty)); + sclk_apply_ratio(clk, sclk); + } + + return 0; +} + +static int sclk_div_get_duty_cycle(struct clk_hw *hw, + struct clk_duty *duty) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + int hi; + + if (!MESON_PARM_APPLICABLE(&sclk->hi)) { + duty->num = 1; + duty->den = 2; + return 0; + } + + hi = meson_parm_read(clk->map, &sclk->hi); + duty->num = hi + 1; + duty->den = sclk->cached_div; + return 0; +} + +static void sclk_apply_divider(struct clk_regmap *clk, + struct meson_sclk_div_data *sclk) +{ + if (MESON_PARM_APPLICABLE(&sclk->hi)) + sclk_apply_ratio(clk, sclk); + + meson_parm_write(clk->map, &sclk->div, sclk->cached_div - 1); +} + +static int sclk_div_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long prate) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + unsigned long maxdiv = sclk_div_maxdiv(sclk); + + sclk->cached_div = sclk_div_getdiv(hw, rate, prate, maxdiv); + + if (clk_hw_is_enabled(hw)) + sclk_apply_divider(clk, sclk); + + return 0; +} + +static unsigned long sclk_div_recalc_rate(struct clk_hw *hw, + unsigned long prate) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + + return DIV_ROUND_UP_ULL((u64)prate, sclk->cached_div); +} + +static int sclk_div_enable(struct clk_hw *hw) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + + sclk_apply_divider(clk, sclk); + + return 0; +} + +static void sclk_div_disable(struct clk_hw *hw) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + + meson_parm_write(clk->map, &sclk->div, 0); +} + +static int sclk_div_is_enabled(struct clk_hw *hw) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + + if (meson_parm_read(clk->map, &sclk->div)) + return 1; + + return 0; +} + +static void sclk_div_init(struct clk_hw *hw) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + unsigned int val; + + val = meson_parm_read(clk->map, &sclk->div); + + /* if the divider is initially disabled, assume max */ + if (!val) + sclk->cached_div = sclk_div_maxdiv(sclk); + else + sclk->cached_div = val + 1; + + sclk_div_get_duty_cycle(hw, &sclk->cached_duty); +} + +const struct clk_ops meson_sclk_div_ops = { + .recalc_rate = sclk_div_recalc_rate, + .round_rate = sclk_div_round_rate, + .set_rate = sclk_div_set_rate, + .enable = sclk_div_enable, + .disable = sclk_div_disable, + .is_enabled = sclk_div_is_enabled, + .get_duty_cycle = sclk_div_get_duty_cycle, + .set_duty_cycle = sclk_div_set_duty_cycle, + .init = sclk_div_init, +}; +EXPORT_SYMBOL_GPL(meson_sclk_div_ops); |