1 files changed, 307 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..661a73284
--- /dev/null
+++ b/drivers/clk/sunxi/clk-factors.c
@@ -0,0 +1,307 @@
+/*
+ * Copyright (C) 2013 Emilio López <emilio@elopez.com.ar>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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);
+}