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-rw-r--r--drivers/clk/sunxi/clk-factors.c304
1 files changed, 304 insertions, 0 deletions
diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
new file mode 100644
index 000000000..4d8f0422b
--- /dev/null
+++ b/drivers/clk/sunxi/clk-factors.c
@@ -0,0 +1,304 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2013 Emilio López <emilio@elopez.com.ar>
+ *
+ * Adjustable factor-based clock implementation
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "clk-factors.h"
+
+/*
+ * DOC: basic adjustable factor-based clock
+ *
+ * Traits of this clock:
+ * prepare - clk_prepare only ensures that parents are prepared
+ * enable - clk_enable only ensures that parents are enabled
+ * rate - rate is adjustable.
+ * clk->rate = (parent->rate * N * (K + 1) >> P) / (M + 1)
+ * parent - fixed parent. No clk_set_parent support
+ */
+
+#define to_clk_factors(_hw) container_of(_hw, struct clk_factors, hw)
+
+#define FACTORS_MAX_PARENTS 5
+
+#define SETMASK(len, pos) (((1U << (len)) - 1) << (pos))
+#define CLRMASK(len, pos) (~(SETMASK(len, pos)))
+#define FACTOR_GET(bit, len, reg) (((reg) & SETMASK(len, bit)) >> (bit))
+
+#define FACTOR_SET(bit, len, reg, val) \
+ (((reg) & CLRMASK(len, bit)) | (val << (bit)))
+
+static unsigned long clk_factors_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ u8 n = 1, k = 0, p = 0, m = 0;
+ u32 reg;
+ unsigned long rate;
+ struct clk_factors *factors = to_clk_factors(hw);
+ const struct clk_factors_config *config = factors->config;
+
+ /* Fetch the register value */
+ reg = readl(factors->reg);
+
+ /* Get each individual factor if applicable */
+ if (config->nwidth != SUNXI_FACTORS_NOT_APPLICABLE)
+ n = FACTOR_GET(config->nshift, config->nwidth, reg);
+ if (config->kwidth != SUNXI_FACTORS_NOT_APPLICABLE)
+ k = FACTOR_GET(config->kshift, config->kwidth, reg);
+ if (config->mwidth != SUNXI_FACTORS_NOT_APPLICABLE)
+ m = FACTOR_GET(config->mshift, config->mwidth, reg);
+ if (config->pwidth != SUNXI_FACTORS_NOT_APPLICABLE)
+ p = FACTOR_GET(config->pshift, config->pwidth, reg);
+
+ if (factors->recalc) {
+ struct factors_request factors_req = {
+ .parent_rate = parent_rate,
+ .n = n,
+ .k = k,
+ .m = m,
+ .p = p,
+ };
+
+ /* get mux details from mux clk structure */
+ if (factors->mux)
+ factors_req.parent_index =
+ (reg >> factors->mux->shift) &
+ factors->mux->mask;
+
+ factors->recalc(&factors_req);
+
+ return factors_req.rate;
+ }
+
+ /* Calculate the rate */
+ rate = (parent_rate * (n + config->n_start) * (k + 1) >> p) / (m + 1);
+
+ return rate;
+}
+
+static int clk_factors_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct clk_factors *factors = to_clk_factors(hw);
+ struct clk_hw *parent, *best_parent = NULL;
+ int i, num_parents;
+ unsigned long parent_rate, best = 0, child_rate, best_child_rate = 0;
+
+ /* find the parent that can help provide the fastest rate <= rate */
+ num_parents = clk_hw_get_num_parents(hw);
+ for (i = 0; i < num_parents; i++) {
+ struct factors_request factors_req = {
+ .rate = req->rate,
+ .parent_index = i,
+ };
+ parent = clk_hw_get_parent_by_index(hw, i);
+ if (!parent)
+ continue;
+ if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)
+ parent_rate = clk_hw_round_rate(parent, req->rate);
+ else
+ parent_rate = clk_hw_get_rate(parent);
+
+ factors_req.parent_rate = parent_rate;
+ factors->get_factors(&factors_req);
+ child_rate = factors_req.rate;
+
+ if (child_rate <= req->rate && child_rate > best_child_rate) {
+ best_parent = parent;
+ best = parent_rate;
+ best_child_rate = child_rate;
+ }
+ }
+
+ if (!best_parent)
+ return -EINVAL;
+
+ req->best_parent_hw = best_parent;
+ req->best_parent_rate = best;
+ req->rate = best_child_rate;
+
+ return 0;
+}
+
+static int clk_factors_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct factors_request req = {
+ .rate = rate,
+ .parent_rate = parent_rate,
+ };
+ u32 reg;
+ struct clk_factors *factors = to_clk_factors(hw);
+ const struct clk_factors_config *config = factors->config;
+ unsigned long flags = 0;
+
+ factors->get_factors(&req);
+
+ if (factors->lock)
+ spin_lock_irqsave(factors->lock, flags);
+
+ /* Fetch the register value */
+ reg = readl(factors->reg);
+
+ /* Set up the new factors - macros do not do anything if width is 0 */
+ reg = FACTOR_SET(config->nshift, config->nwidth, reg, req.n);
+ reg = FACTOR_SET(config->kshift, config->kwidth, reg, req.k);
+ reg = FACTOR_SET(config->mshift, config->mwidth, reg, req.m);
+ reg = FACTOR_SET(config->pshift, config->pwidth, reg, req.p);
+
+ /* Apply them now */
+ writel(reg, factors->reg);
+
+ /* delay 500us so pll stabilizes */
+ __delay((rate >> 20) * 500 / 2);
+
+ if (factors->lock)
+ spin_unlock_irqrestore(factors->lock, flags);
+
+ return 0;
+}
+
+static const struct clk_ops clk_factors_ops = {
+ .determine_rate = clk_factors_determine_rate,
+ .recalc_rate = clk_factors_recalc_rate,
+ .set_rate = clk_factors_set_rate,
+};
+
+static struct clk *__sunxi_factors_register(struct device_node *node,
+ const struct factors_data *data,
+ spinlock_t *lock, void __iomem *reg,
+ unsigned long flags)
+{
+ struct clk *clk;
+ struct clk_factors *factors;
+ struct clk_gate *gate = NULL;
+ struct clk_mux *mux = NULL;
+ struct clk_hw *gate_hw = NULL;
+ struct clk_hw *mux_hw = NULL;
+ const char *clk_name = node->name;
+ const char *parents[FACTORS_MAX_PARENTS];
+ int ret, i = 0;
+
+ /* if we have a mux, we will have >1 parents */
+ i = of_clk_parent_fill(node, parents, FACTORS_MAX_PARENTS);
+
+ /*
+ * some factor clocks, such as pll5 and pll6, may have multiple
+ * outputs, and have their name designated in factors_data
+ */
+ if (data->name)
+ clk_name = data->name;
+ else
+ of_property_read_string(node, "clock-output-names", &clk_name);
+
+ factors = kzalloc(sizeof(struct clk_factors), GFP_KERNEL);
+ if (!factors)
+ goto err_factors;
+
+ /* set up factors properties */
+ factors->reg = reg;
+ factors->config = data->table;
+ factors->get_factors = data->getter;
+ factors->recalc = data->recalc;
+ factors->lock = lock;
+
+ /* Add a gate if this factor clock can be gated */
+ if (data->enable) {
+ gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL);
+ if (!gate)
+ goto err_gate;
+
+ factors->gate = gate;
+
+ /* set up gate properties */
+ gate->reg = reg;
+ gate->bit_idx = data->enable;
+ gate->lock = factors->lock;
+ gate_hw = &gate->hw;
+ }
+
+ /* Add a mux if this factor clock can be muxed */
+ if (data->mux) {
+ mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL);
+ if (!mux)
+ goto err_mux;
+
+ factors->mux = mux;
+
+ /* set up gate properties */
+ mux->reg = reg;
+ mux->shift = data->mux;
+ mux->mask = data->muxmask;
+ mux->lock = factors->lock;
+ mux_hw = &mux->hw;
+ }
+
+ clk = clk_register_composite(NULL, clk_name,
+ parents, i,
+ mux_hw, &clk_mux_ops,
+ &factors->hw, &clk_factors_ops,
+ gate_hw, &clk_gate_ops, CLK_IS_CRITICAL);
+ if (IS_ERR(clk))
+ goto err_register;
+
+ ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
+ if (ret)
+ goto err_provider;
+
+ return clk;
+
+err_provider:
+ /* TODO: The composite clock stuff will leak a bit here. */
+ clk_unregister(clk);
+err_register:
+ kfree(mux);
+err_mux:
+ kfree(gate);
+err_gate:
+ kfree(factors);
+err_factors:
+ return NULL;
+}
+
+struct clk *sunxi_factors_register(struct device_node *node,
+ const struct factors_data *data,
+ spinlock_t *lock,
+ void __iomem *reg)
+{
+ return __sunxi_factors_register(node, data, lock, reg, 0);
+}
+
+struct clk *sunxi_factors_register_critical(struct device_node *node,
+ const struct factors_data *data,
+ spinlock_t *lock,
+ void __iomem *reg)
+{
+ return __sunxi_factors_register(node, data, lock, reg, CLK_IS_CRITICAL);
+}
+
+void sunxi_factors_unregister(struct device_node *node, struct clk *clk)
+{
+ struct clk_hw *hw = __clk_get_hw(clk);
+ struct clk_factors *factors;
+
+ if (!hw)
+ return;
+
+ factors = to_clk_factors(hw);
+
+ of_clk_del_provider(node);
+ /* TODO: The composite clock stuff will leak a bit here. */
+ clk_unregister(clk);
+ kfree(factors->mux);
+ kfree(factors->gate);
+ kfree(factors);
+}