summaryrefslogtreecommitdiffstats
path: root/drivers/clk/sunxi-ng/ccu_mp.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/clk/sunxi-ng/ccu_mp.c')
-rw-r--r--drivers/clk/sunxi-ng/ccu_mp.c330
1 files changed, 330 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/ccu_mp.c b/drivers/clk/sunxi-ng/ccu_mp.c
new file mode 100644
index 0000000000..cc94a694cb
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_mp.c
@@ -0,0 +1,330 @@
+// 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_gate.h"
+#include "ccu_mp.h"
+
+static unsigned long ccu_mp_find_best(unsigned long parent, unsigned long rate,
+ unsigned int max_m, unsigned int max_p,
+ unsigned int *m, unsigned int *p)
+{
+ unsigned long best_rate = 0;
+ unsigned int best_m = 0, best_p = 0;
+ unsigned int _m, _p;
+
+ for (_p = 1; _p <= max_p; _p <<= 1) {
+ for (_m = 1; _m <= max_m; _m++) {
+ unsigned long tmp_rate = parent / _p / _m;
+
+ if (tmp_rate > rate)
+ continue;
+
+ if ((rate - tmp_rate) < (rate - best_rate)) {
+ best_rate = tmp_rate;
+ best_m = _m;
+ best_p = _p;
+ }
+ }
+ }
+
+ *m = best_m;
+ *p = best_p;
+
+ return best_rate;
+}
+
+static unsigned long ccu_mp_find_best_with_parent_adj(struct clk_hw *hw,
+ unsigned long *parent,
+ unsigned long rate,
+ unsigned int max_m,
+ unsigned int max_p)
+{
+ unsigned long parent_rate_saved;
+ unsigned long parent_rate, now;
+ unsigned long best_rate = 0;
+ unsigned int _m, _p, div;
+ unsigned long maxdiv;
+
+ parent_rate_saved = *parent;
+
+ /*
+ * The maximum divider we can use without overflowing
+ * unsigned long in rate * m * p below
+ */
+ maxdiv = max_m * max_p;
+ maxdiv = min(ULONG_MAX / rate, maxdiv);
+
+ for (_p = 1; _p <= max_p; _p <<= 1) {
+ for (_m = 1; _m <= max_m; _m++) {
+ div = _m * _p;
+
+ if (div > maxdiv)
+ break;
+
+ if (rate * div == parent_rate_saved) {
+ /*
+ * 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.
+ */
+ *parent = parent_rate_saved;
+ return rate;
+ }
+
+ parent_rate = clk_hw_round_rate(hw, rate * div);
+ now = parent_rate / div;
+
+ if (now <= rate && now > best_rate) {
+ best_rate = now;
+ *parent = parent_rate;
+
+ if (now == rate)
+ return rate;
+ }
+ }
+ }
+
+ return best_rate;
+}
+
+static unsigned long ccu_mp_round_rate(struct ccu_mux_internal *mux,
+ struct clk_hw *hw,
+ unsigned long *parent_rate,
+ unsigned long rate,
+ void *data)
+{
+ struct ccu_mp *cmp = data;
+ unsigned int max_m, max_p;
+ unsigned int m, p;
+
+ if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate *= cmp->fixed_post_div;
+
+ max_m = cmp->m.max ?: 1 << cmp->m.width;
+ max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1);
+
+ if (!clk_hw_can_set_rate_parent(&cmp->common.hw)) {
+ rate = ccu_mp_find_best(*parent_rate, rate, max_m, max_p, &m, &p);
+ } else {
+ rate = ccu_mp_find_best_with_parent_adj(hw, parent_rate, rate,
+ max_m, max_p);
+ }
+
+ if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate /= cmp->fixed_post_div;
+
+ return rate;
+}
+
+static void ccu_mp_disable(struct clk_hw *hw)
+{
+ struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+ return ccu_gate_helper_disable(&cmp->common, cmp->enable);
+}
+
+static int ccu_mp_enable(struct clk_hw *hw)
+{
+ struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+ return ccu_gate_helper_enable(&cmp->common, cmp->enable);
+}
+
+static int ccu_mp_is_enabled(struct clk_hw *hw)
+{
+ struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+ return ccu_gate_helper_is_enabled(&cmp->common, cmp->enable);
+}
+
+static unsigned long ccu_mp_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+ unsigned long rate;
+ unsigned int m, p;
+ u32 reg;
+
+ /* Adjust parent_rate according to pre-dividers */
+ parent_rate = ccu_mux_helper_apply_prediv(&cmp->common, &cmp->mux, -1,
+ parent_rate);
+
+ reg = readl(cmp->common.base + cmp->common.reg);
+
+ m = reg >> cmp->m.shift;
+ m &= (1 << cmp->m.width) - 1;
+ m += cmp->m.offset;
+ if (!m)
+ m++;
+
+ p = reg >> cmp->p.shift;
+ p &= (1 << cmp->p.width) - 1;
+
+ rate = (parent_rate >> p) / m;
+ if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate /= cmp->fixed_post_div;
+
+ return rate;
+}
+
+static int ccu_mp_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+ return ccu_mux_helper_determine_rate(&cmp->common, &cmp->mux,
+ req, ccu_mp_round_rate, cmp);
+}
+
+static int ccu_mp_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+ unsigned long flags;
+ unsigned int max_m, max_p;
+ unsigned int m, p;
+ u32 reg;
+
+ /* Adjust parent_rate according to pre-dividers */
+ parent_rate = ccu_mux_helper_apply_prediv(&cmp->common, &cmp->mux, -1,
+ parent_rate);
+
+ max_m = cmp->m.max ?: 1 << cmp->m.width;
+ max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1);
+
+ /* Adjust target rate according to post-dividers */
+ if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate = rate * cmp->fixed_post_div;
+
+ ccu_mp_find_best(parent_rate, rate, max_m, max_p, &m, &p);
+
+ spin_lock_irqsave(cmp->common.lock, flags);
+
+ reg = readl(cmp->common.base + cmp->common.reg);
+ reg &= ~GENMASK(cmp->m.width + cmp->m.shift - 1, cmp->m.shift);
+ reg &= ~GENMASK(cmp->p.width + cmp->p.shift - 1, cmp->p.shift);
+ reg |= (m - cmp->m.offset) << cmp->m.shift;
+ reg |= ilog2(p) << cmp->p.shift;
+
+ writel(reg, cmp->common.base + cmp->common.reg);
+
+ spin_unlock_irqrestore(cmp->common.lock, flags);
+
+ return 0;
+}
+
+static u8 ccu_mp_get_parent(struct clk_hw *hw)
+{
+ struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+ return ccu_mux_helper_get_parent(&cmp->common, &cmp->mux);
+}
+
+static int ccu_mp_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+ return ccu_mux_helper_set_parent(&cmp->common, &cmp->mux, index);
+}
+
+const struct clk_ops ccu_mp_ops = {
+ .disable = ccu_mp_disable,
+ .enable = ccu_mp_enable,
+ .is_enabled = ccu_mp_is_enabled,
+
+ .get_parent = ccu_mp_get_parent,
+ .set_parent = ccu_mp_set_parent,
+
+ .determine_rate = ccu_mp_determine_rate,
+ .recalc_rate = ccu_mp_recalc_rate,
+ .set_rate = ccu_mp_set_rate,
+};
+EXPORT_SYMBOL_NS_GPL(ccu_mp_ops, SUNXI_CCU);
+
+/*
+ * Support for MMC timing mode switching
+ *
+ * The MMC clocks on some SoCs support switching between old and
+ * new timing modes. A platform specific API is provided to query
+ * and set the timing mode on supported SoCs.
+ *
+ * In addition, a special class of ccu_mp_ops is provided, which
+ * takes in to account the timing mode switch. When the new timing
+ * mode is active, the clock output rate is halved. This new class
+ * is a wrapper around the generic ccu_mp_ops. When clock rates
+ * are passed through to ccu_mp_ops callbacks, they are doubled
+ * if the new timing mode bit is set, to account for the post
+ * divider. Conversely, when clock rates are passed back, they
+ * are halved if the mode bit is set.
+ */
+
+static unsigned long ccu_mp_mmc_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ unsigned long rate = ccu_mp_recalc_rate(hw, parent_rate);
+ struct ccu_common *cm = hw_to_ccu_common(hw);
+ u32 val = readl(cm->base + cm->reg);
+
+ if (val & CCU_MMC_NEW_TIMING_MODE)
+ return rate / 2;
+ return rate;
+}
+
+static int ccu_mp_mmc_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct ccu_common *cm = hw_to_ccu_common(hw);
+ u32 val = readl(cm->base + cm->reg);
+ int ret;
+
+ /* adjust the requested clock rate */
+ if (val & CCU_MMC_NEW_TIMING_MODE) {
+ req->rate *= 2;
+ req->min_rate *= 2;
+ req->max_rate *= 2;
+ }
+
+ ret = ccu_mp_determine_rate(hw, req);
+
+ /* re-adjust the requested clock rate back */
+ if (val & CCU_MMC_NEW_TIMING_MODE) {
+ req->rate /= 2;
+ req->min_rate /= 2;
+ req->max_rate /= 2;
+ }
+
+ return ret;
+}
+
+static int ccu_mp_mmc_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct ccu_common *cm = hw_to_ccu_common(hw);
+ u32 val = readl(cm->base + cm->reg);
+
+ if (val & CCU_MMC_NEW_TIMING_MODE)
+ rate *= 2;
+
+ return ccu_mp_set_rate(hw, rate, parent_rate);
+}
+
+const struct clk_ops ccu_mp_mmc_ops = {
+ .disable = ccu_mp_disable,
+ .enable = ccu_mp_enable,
+ .is_enabled = ccu_mp_is_enabled,
+
+ .get_parent = ccu_mp_get_parent,
+ .set_parent = ccu_mp_set_parent,
+
+ .determine_rate = ccu_mp_mmc_determine_rate,
+ .recalc_rate = ccu_mp_mmc_recalc_rate,
+ .set_rate = ccu_mp_mmc_set_rate,
+};
+EXPORT_SYMBOL_NS_GPL(ccu_mp_mmc_ops, SUNXI_CCU);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 13:37:37 +0000