summaryrefslogtreecommitdiffstats
path: root/drivers/clk/actions/owl-factor.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/clk/actions/owl-factor.c')
-rw-r--r--drivers/clk/actions/owl-factor.c220
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 0000000000..64f316cf7c
--- /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, &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);
+
+ 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,
+};