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Diffstat (limited to '')
| -rw-r--r-- | drivers/clk/actions/owl-factor.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/clk/actions/owl-factor.c b/drivers/clk/actions/owl-factor.c new file mode 100644 index 000000000..64f316cf7 --- /dev/null +++ b/drivers/clk/actions/owl-factor.c @@ -0,0 +1,220 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// OWL factor clock driver +// +// Copyright (c) 2014 Actions Semi Inc. +// Author: David Liu <liuwei@actions-semi.com> +// +// Copyright (c) 2018 Linaro Ltd. +// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> + +#include <linux/clk-provider.h> +#include <linux/regmap.h> + +#include "owl-factor.h" + +static unsigned int _get_table_maxval(const struct clk_factor_table *table) +{ + unsigned int maxval = 0; + const struct clk_factor_table *clkt; + + for (clkt = table; clkt->div; clkt++) + if (clkt->val > maxval) + maxval = clkt->val; + return maxval; +} + +static int _get_table_div_mul(const struct clk_factor_table *table, + unsigned int val, unsigned int *mul, unsigned int *div) +{ + const struct clk_factor_table *clkt; + + for (clkt = table; clkt->div; clkt++) { + if (clkt->val == val) { + *mul = clkt->mul; + *div = clkt->div; + return 1; + } + } + + return 0; +} + +static unsigned int _get_table_val(const struct clk_factor_table *table, + unsigned long rate, unsigned long parent_rate) +{ + const struct clk_factor_table *clkt; + int val = -1; + u64 calc_rate; + + for (clkt = table; clkt->div; clkt++) { + calc_rate = parent_rate * clkt->mul; + do_div(calc_rate, clkt->div); + + if ((unsigned long)calc_rate <= rate) { + val = clkt->val; + break; + } + } + + if (val == -1) + val = _get_table_maxval(table); + + return val; +} + +static int owl_clk_val_best(const struct owl_factor_hw *factor_hw, + struct clk_hw *hw, unsigned long rate, + unsigned long *best_parent_rate) +{ + const struct clk_factor_table *clkt = factor_hw->table; + unsigned long parent_rate, try_parent_rate, best = 0, cur_rate; + unsigned long parent_rate_saved = *best_parent_rate; + int bestval = 0; + + if (!rate) + rate = 1; + + if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) { + parent_rate = *best_parent_rate; + bestval = _get_table_val(clkt, rate, parent_rate); + return bestval; + } + + for (clkt = factor_hw->table; clkt->div; clkt++) { + try_parent_rate = rate * clkt->div / clkt->mul; + + if (try_parent_rate == parent_rate_saved) { + pr_debug("%s: [%d %d %d] found try_parent_rate %ld\n", + __func__, clkt->val, clkt->mul, clkt->div, + try_parent_rate); + /* + * It's the most ideal case if the requested rate can be + * divided from parent clock without any need to change + * parent rate, so return the divider immediately. + */ + *best_parent_rate = parent_rate_saved; + return clkt->val; + } + + parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), + try_parent_rate); + cur_rate = DIV_ROUND_UP(parent_rate, clkt->div) * clkt->mul; + if (cur_rate <= rate && cur_rate > best) { + bestval = clkt->val; + best = cur_rate; + *best_parent_rate = parent_rate; + } + } + + if (!bestval) { + bestval = _get_table_maxval(clkt); + *best_parent_rate = clk_hw_round_rate( + clk_hw_get_parent(hw), 1); + } + + return bestval; +} + +long owl_factor_helper_round_rate(struct owl_clk_common *common, + const struct owl_factor_hw *factor_hw, + unsigned long rate, + unsigned long *parent_rate) +{ + const struct clk_factor_table *clkt = factor_hw->table; + unsigned int val, mul = 0, div = 1; + + val = owl_clk_val_best(factor_hw, &common->hw, rate, parent_rate); + _get_table_div_mul(clkt, val, &mul, &div); + + return *parent_rate * mul / div; +} + +static long owl_factor_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct owl_factor *factor = hw_to_owl_factor(hw); + struct owl_factor_hw *factor_hw = &factor->factor_hw; + + return owl_factor_helper_round_rate(&factor->common, factor_hw, + rate, parent_rate); +} + +unsigned long owl_factor_helper_recalc_rate(struct owl_clk_common *common, + const struct owl_factor_hw *factor_hw, + unsigned long parent_rate) +{ + const struct clk_factor_table *clkt = factor_hw->table; + unsigned long long int rate; + u32 reg, val, mul, div; + + div = 0; + mul = 0; + + regmap_read(common->regmap, factor_hw->reg, ®); + + val = reg >> factor_hw->shift; + val &= div_mask(factor_hw); + + _get_table_div_mul(clkt, val, &mul, &div); + if (!div) { + WARN(!(factor_hw->fct_flags & CLK_DIVIDER_ALLOW_ZERO), + "%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n", + __clk_get_name(common->hw.clk)); + return parent_rate; + } + + rate = (unsigned long long int)parent_rate * mul; + do_div(rate, div); + + return rate; +} + +static unsigned long owl_factor_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct owl_factor *factor = hw_to_owl_factor(hw); + struct owl_factor_hw *factor_hw = &factor->factor_hw; + struct owl_clk_common *common = &factor->common; + + return owl_factor_helper_recalc_rate(common, factor_hw, parent_rate); +} + +int owl_factor_helper_set_rate(const struct owl_clk_common *common, + const struct owl_factor_hw *factor_hw, + unsigned long rate, + unsigned long parent_rate) +{ + u32 val, reg; + + val = _get_table_val(factor_hw->table, rate, parent_rate); + + if (val > div_mask(factor_hw)) + val = div_mask(factor_hw); + + regmap_read(common->regmap, factor_hw->reg, ®); + + reg &= ~(div_mask(factor_hw) << factor_hw->shift); + reg |= val << factor_hw->shift; + + regmap_write(common->regmap, factor_hw->reg, reg); + + return 0; +} + +static int owl_factor_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct owl_factor *factor = hw_to_owl_factor(hw); + struct owl_factor_hw *factor_hw = &factor->factor_hw; + struct owl_clk_common *common = &factor->common; + + return owl_factor_helper_set_rate(common, factor_hw, + rate, parent_rate); +} + +const struct clk_ops owl_factor_ops = { + .round_rate = owl_factor_round_rate, + .recalc_rate = owl_factor_recalc_rate, + .set_rate = owl_factor_set_rate, +}; |