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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/clk/meson/sclk-div.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/clk/meson/sclk-div.c')
-rw-r--r-- | drivers/clk/meson/sclk-div.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/drivers/clk/meson/sclk-div.c b/drivers/clk/meson/sclk-div.c new file mode 100644 index 000000000..76d31c0a3 --- /dev/null +++ b/drivers/clk/meson/sclk-div.c @@ -0,0 +1,253 @@ +// 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 <linux/clk-provider.h> +#include <linux/module.h> + +#include "clk-regmap.h" +#include "sclk-div.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 int 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); + + return 0; +} + +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); + +MODULE_DESCRIPTION("Amlogic Sample divider driver"); +MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>"); +MODULE_LICENSE("GPL v2"); |