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path: root/drivers/clk/sunxi-ng/ccu_nm.c
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-rw-r--r--drivers/clk/sunxi-ng/ccu_nm.c240
1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c
new file mode 100644
index 000000000..e6bcc0a71
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_nm.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2016 Maxime Ripard
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+
+#include "ccu_frac.h"
+#include "ccu_gate.h"
+#include "ccu_nm.h"
+
+struct _ccu_nm {
+ unsigned long n, min_n, max_n;
+ unsigned long m, min_m, max_m;
+};
+
+static unsigned long ccu_nm_calc_rate(unsigned long parent,
+ unsigned long n, unsigned long m)
+{
+ u64 rate = parent;
+
+ rate *= n;
+ do_div(rate, m);
+
+ return rate;
+}
+
+static void ccu_nm_find_best(unsigned long parent, unsigned long rate,
+ struct _ccu_nm *nm)
+{
+ unsigned long best_rate = 0;
+ unsigned long best_n = 0, best_m = 0;
+ unsigned long _n, _m;
+
+ for (_n = nm->min_n; _n <= nm->max_n; _n++) {
+ for (_m = nm->min_m; _m <= nm->max_m; _m++) {
+ unsigned long tmp_rate = ccu_nm_calc_rate(parent,
+ _n, _m);
+
+ if (tmp_rate > rate)
+ continue;
+
+ if ((rate - tmp_rate) < (rate - best_rate)) {
+ best_rate = tmp_rate;
+ best_n = _n;
+ best_m = _m;
+ }
+ }
+ }
+
+ nm->n = best_n;
+ nm->m = best_m;
+}
+
+static void ccu_nm_disable(struct clk_hw *hw)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+
+ return ccu_gate_helper_disable(&nm->common, nm->enable);
+}
+
+static int ccu_nm_enable(struct clk_hw *hw)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+
+ return ccu_gate_helper_enable(&nm->common, nm->enable);
+}
+
+static int ccu_nm_is_enabled(struct clk_hw *hw)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+
+ return ccu_gate_helper_is_enabled(&nm->common, nm->enable);
+}
+
+static unsigned long ccu_nm_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+ unsigned long rate;
+ unsigned long n, m;
+ u32 reg;
+
+ if (ccu_frac_helper_is_enabled(&nm->common, &nm->frac)) {
+ rate = ccu_frac_helper_read_rate(&nm->common, &nm->frac);
+
+ if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate /= nm->fixed_post_div;
+
+ return rate;
+ }
+
+ reg = readl(nm->common.base + nm->common.reg);
+
+ n = reg >> nm->n.shift;
+ n &= (1 << nm->n.width) - 1;
+ n += nm->n.offset;
+ if (!n)
+ n++;
+
+ m = reg >> nm->m.shift;
+ m &= (1 << nm->m.width) - 1;
+ m += nm->m.offset;
+ if (!m)
+ m++;
+
+ if (ccu_sdm_helper_is_enabled(&nm->common, &nm->sdm))
+ rate = ccu_sdm_helper_read_rate(&nm->common, &nm->sdm, m, n);
+ else
+ rate = ccu_nm_calc_rate(parent_rate, n, m);
+
+ if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate /= nm->fixed_post_div;
+
+ return rate;
+}
+
+static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+ struct _ccu_nm _nm;
+
+ if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate *= nm->fixed_post_div;
+
+ if (rate < nm->min_rate) {
+ rate = nm->min_rate;
+ if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate /= nm->fixed_post_div;
+ return rate;
+ }
+
+ if (nm->max_rate && rate > nm->max_rate) {
+ rate = nm->max_rate;
+ if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate /= nm->fixed_post_div;
+ return rate;
+ }
+
+ if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) {
+ if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate /= nm->fixed_post_div;
+ return rate;
+ }
+
+ if (ccu_sdm_helper_has_rate(&nm->common, &nm->sdm, rate)) {
+ if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate /= nm->fixed_post_div;
+ return rate;
+ }
+
+ _nm.min_n = nm->n.min ?: 1;
+ _nm.max_n = nm->n.max ?: 1 << nm->n.width;
+ _nm.min_m = 1;
+ _nm.max_m = nm->m.max ?: 1 << nm->m.width;
+
+ ccu_nm_find_best(*parent_rate, rate, &_nm);
+ rate = ccu_nm_calc_rate(*parent_rate, _nm.n, _nm.m);
+
+ if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate /= nm->fixed_post_div;
+
+ return rate;
+}
+
+static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+ struct _ccu_nm _nm;
+ unsigned long flags;
+ u32 reg;
+
+ /* Adjust target rate according to post-dividers */
+ if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate = rate * nm->fixed_post_div;
+
+ if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) {
+ spin_lock_irqsave(nm->common.lock, flags);
+
+ /* most SoCs require M to be 0 if fractional mode is used */
+ reg = readl(nm->common.base + nm->common.reg);
+ reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
+ writel(reg, nm->common.base + nm->common.reg);
+
+ spin_unlock_irqrestore(nm->common.lock, flags);
+
+ ccu_frac_helper_enable(&nm->common, &nm->frac);
+
+ return ccu_frac_helper_set_rate(&nm->common, &nm->frac,
+ rate, nm->lock);
+ } else {
+ ccu_frac_helper_disable(&nm->common, &nm->frac);
+ }
+
+ _nm.min_n = nm->n.min ?: 1;
+ _nm.max_n = nm->n.max ?: 1 << nm->n.width;
+ _nm.min_m = 1;
+ _nm.max_m = nm->m.max ?: 1 << nm->m.width;
+
+ if (ccu_sdm_helper_has_rate(&nm->common, &nm->sdm, rate)) {
+ ccu_sdm_helper_enable(&nm->common, &nm->sdm, rate);
+
+ /* Sigma delta modulation requires specific N and M factors */
+ ccu_sdm_helper_get_factors(&nm->common, &nm->sdm, rate,
+ &_nm.m, &_nm.n);
+ } else {
+ ccu_sdm_helper_disable(&nm->common, &nm->sdm);
+ ccu_nm_find_best(parent_rate, rate, &_nm);
+ }
+
+ spin_lock_irqsave(nm->common.lock, flags);
+
+ reg = readl(nm->common.base + nm->common.reg);
+ reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift);
+ reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
+
+ reg |= (_nm.n - nm->n.offset) << nm->n.shift;
+ reg |= (_nm.m - nm->m.offset) << nm->m.shift;
+ writel(reg, nm->common.base + nm->common.reg);
+
+ spin_unlock_irqrestore(nm->common.lock, flags);
+
+ ccu_helper_wait_for_lock(&nm->common, nm->lock);
+
+ return 0;
+}
+
+const struct clk_ops ccu_nm_ops = {
+ .disable = ccu_nm_disable,
+ .enable = ccu_nm_enable,
+ .is_enabled = ccu_nm_is_enabled,
+
+ .recalc_rate = ccu_nm_recalc_rate,
+ .round_rate = ccu_nm_round_rate,
+ .set_rate = ccu_nm_set_rate,
+};