1 files changed, 331 insertions, 0 deletions
diff --git a/drivers/clk/st/clk-flexgen.c b/drivers/clk/st/clk-flexgen.c
new file mode 100644
index 000000000000..2282cef9f2ff
--- /dev/null
+++ b/drivers/clk/st/clk-flexgen.c
@@ -0,0 +1,331 @@
+/*
+ * clk-flexgen.c
+ *
+ * Copyright (C) ST-Microelectronics SA 2013
+ * Author:  Maxime Coquelin <maxime.coquelin@st.com> for ST-Microelectronics.
+ * License terms:  GNU General Public License (GPL), version 2  */
+
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+struct flexgen {
+	struct clk_hw hw;
+
+	/* Crossbar */
+	struct clk_mux mux;
+	/* Pre-divisor's gate */
+	struct clk_gate pgate;
+	/* Pre-divisor */
+	struct clk_divider pdiv;
+	/* Final divisor's gate */
+	struct clk_gate fgate;
+	/* Final divisor */
+	struct clk_divider fdiv;
+};
+
+#define to_flexgen(_hw) container_of(_hw, struct flexgen, hw)
+
+static int flexgen_enable(struct clk_hw *hw)
+{
+	struct flexgen *flexgen = to_flexgen(hw);
+	struct clk_hw *pgate_hw = &flexgen->pgate.hw;
+	struct clk_hw *fgate_hw = &flexgen->fgate.hw;
+
+	pgate_hw->clk = hw->clk;
+	fgate_hw->clk = hw->clk;
+
+	clk_gate_ops.enable(pgate_hw);
+
+	clk_gate_ops.enable(fgate_hw);
+
+	pr_debug("%s: flexgen output enabled\n", __clk_get_name(hw->clk));
+	return 0;
+}
+
+static void flexgen_disable(struct clk_hw *hw)
+{
+	struct flexgen *flexgen = to_flexgen(hw);
+	struct clk_hw *fgate_hw = &flexgen->fgate.hw;
+
+	/* disable only the final gate */
+	fgate_hw->clk = hw->clk;
+
+	clk_gate_ops.disable(fgate_hw);
+
+	pr_debug("%s: flexgen output disabled\n", __clk_get_name(hw->clk));
+}
+
+static int flexgen_is_enabled(struct clk_hw *hw)
+{
+	struct flexgen *flexgen = to_flexgen(hw);
+	struct clk_hw *fgate_hw = &flexgen->fgate.hw;
+
+	fgate_hw->clk = hw->clk;
+
+	if (!clk_gate_ops.is_enabled(fgate_hw))
+		return 0;
+
+	return 1;
+}
+
+static u8 flexgen_get_parent(struct clk_hw *hw)
+{
+	struct flexgen *flexgen = to_flexgen(hw);
+	struct clk_hw *mux_hw = &flexgen->mux.hw;
+
+	mux_hw->clk = hw->clk;
+
+	return clk_mux_ops.get_parent(mux_hw);
+}
+
+static int flexgen_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct flexgen *flexgen = to_flexgen(hw);
+	struct clk_hw *mux_hw = &flexgen->mux.hw;
+
+	mux_hw->clk = hw->clk;
+
+	return clk_mux_ops.set_parent(mux_hw, index);
+}
+
+static inline unsigned long
+clk_best_div(unsigned long parent_rate, unsigned long rate)
+{
+	return parent_rate / rate + ((rate > (2*(parent_rate % rate))) ? 0 : 1);
+}
+
+static long flexgen_round_rate(struct clk_hw *hw, unsigned long rate,
+				   unsigned long *prate)
+{
+	unsigned long div;
+
+	/* Round div according to exact prate and wished rate */
+	div = clk_best_div(*prate, rate);
+
+	if (__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT) {
+		*prate = rate * div;
+		return rate;
+	}
+
+	return *prate / div;
+}
+
+unsigned long flexgen_recalc_rate(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	struct flexgen *flexgen = to_flexgen(hw);
+	struct clk_hw *pdiv_hw = &flexgen->pdiv.hw;
+	struct clk_hw *fdiv_hw = &flexgen->fdiv.hw;
+	unsigned long mid_rate;
+
+	pdiv_hw->clk = hw->clk;
+	fdiv_hw->clk = hw->clk;
+
+	mid_rate = clk_divider_ops.recalc_rate(pdiv_hw, parent_rate);
+
+	return clk_divider_ops.recalc_rate(fdiv_hw, mid_rate);
+}
+
+static int flexgen_set_rate(struct clk_hw *hw, unsigned long rate,
+				unsigned long parent_rate)
+{
+	struct flexgen *flexgen = to_flexgen(hw);
+	struct clk_hw *pdiv_hw = &flexgen->pdiv.hw;
+	struct clk_hw *fdiv_hw = &flexgen->fdiv.hw;
+	unsigned long primary_div = 0;
+	int ret = 0;
+
+	pdiv_hw->clk = hw->clk;
+	fdiv_hw->clk = hw->clk;
+
+	primary_div = clk_best_div(parent_rate, rate);
+
+	clk_divider_ops.set_rate(fdiv_hw, parent_rate, parent_rate);
+	ret = clk_divider_ops.set_rate(pdiv_hw, rate, rate * primary_div);
+
+	return ret;
+}
+
+static const struct clk_ops flexgen_ops = {
+	.enable = flexgen_enable,
+	.disable = flexgen_disable,
+	.is_enabled = flexgen_is_enabled,
+	.get_parent = flexgen_get_parent,
+	.set_parent = flexgen_set_parent,
+	.round_rate = flexgen_round_rate,
+	.recalc_rate = flexgen_recalc_rate,
+	.set_rate = flexgen_set_rate,
+};
+
+struct clk *clk_register_flexgen(const char *name,
+				const char **parent_names, u8 num_parents,
+				void __iomem *reg, spinlock_t *lock, u32 idx,
+				unsigned long flexgen_flags) {
+	struct flexgen *fgxbar;
+	struct clk *clk;
+	struct clk_init_data init;
+	u32  xbar_shift;
+	void __iomem *xbar_reg, *fdiv_reg;
+
+	fgxbar = kzalloc(sizeof(struct flexgen), GFP_KERNEL);
+	if (!fgxbar)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &flexgen_ops;
+	init.flags = CLK_IS_BASIC | flexgen_flags;
+	init.parent_names = parent_names;
+	init.num_parents = num_parents;
+
+	xbar_reg = reg + 0x18 + (idx & ~0x3);
+	xbar_shift = (idx % 4) * 0x8;
+	fdiv_reg = reg + 0x164 + idx * 4;
+
+	/* Crossbar element config */
+	fgxbar->mux.lock = lock;
+	fgxbar->mux.mask = BIT(6) - 1;
+	fgxbar->mux.reg = xbar_reg;
+	fgxbar->mux.shift = xbar_shift;
+	fgxbar->mux.table = NULL;
+
+
+	/* Pre-divider's gate config (in xbar register)*/
+	fgxbar->pgate.lock = lock;
+	fgxbar->pgate.reg = xbar_reg;
+	fgxbar->pgate.bit_idx = xbar_shift + 6;
+
+	/* Pre-divider config */
+	fgxbar->pdiv.lock = lock;
+	fgxbar->pdiv.reg = reg + 0x58 + idx * 4;
+	fgxbar->pdiv.width = 10;
+
+	/* Final divider's gate config */
+	fgxbar->fgate.lock = lock;
+	fgxbar->fgate.reg = fdiv_reg;
+	fgxbar->fgate.bit_idx = 6;
+
+	/* Final divider config */
+	fgxbar->fdiv.lock = lock;
+	fgxbar->fdiv.reg = fdiv_reg;
+	fgxbar->fdiv.width = 6;
+
+	fgxbar->hw.init = &init;
+
+	clk = clk_register(NULL, &fgxbar->hw);
+	if (IS_ERR(clk))
+		kfree(fgxbar);
+	else
+		pr_debug("%s: parent %s rate %u\n",
+			__clk_get_name(clk),
+			__clk_get_name(clk_get_parent(clk)),
+			(unsigned int)clk_get_rate(clk));
+	return clk;
+}
+
+static const char ** __init flexgen_get_parents(struct device_node *np,
+						       int *num_parents)
+{
+	const char **parents;
+	int nparents, i;
+
+	nparents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
+	if (WARN_ON(nparents <= 0))
+		return NULL;
+
+	parents = kcalloc(nparents, sizeof(const char *), GFP_KERNEL);
+	if (!parents)
+		return NULL;
+
+	for (i = 0; i < nparents; i++)
+		parents[i] = of_clk_get_parent_name(np, i);
+
+	*num_parents = nparents;
+	return parents;
+}
+
+void __init st_of_flexgen_setup(struct device_node *np)
+{
+	struct device_node *pnode;
+	void __iomem *reg;
+	struct clk_onecell_data *clk_data;
+	const char **parents;
+	int num_parents, i;
+	spinlock_t *rlock = NULL;
+	unsigned long flex_flags = 0;
+
+	pnode = of_get_parent(np);
+	if (!pnode)
+		return;
+
+	reg = of_iomap(pnode, 0);
+	if (!reg)
+		return;
+
+	parents = flexgen_get_parents(np, &num_parents);
+	if (!parents)
+		return;
+
+	clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
+	if (!clk_data)
+		goto err;
+
+	clk_data->clk_num = of_property_count_strings(np ,
+			"clock-output-names");
+	if (clk_data->clk_num <= 0) {
+		pr_err("%s: Failed to get number of output clocks (%d)",
+				__func__, clk_data->clk_num);
+		goto err;
+	}
+
+	clk_data->clks = kcalloc(clk_data->clk_num, sizeof(struct clk *),
+			GFP_KERNEL);
+	if (!clk_data->clks)
+		goto err;
+
+	rlock = kzalloc(sizeof(spinlock_t), GFP_KERNEL);
+	if (!rlock)
+		goto err;
+
+	for (i = 0; i < clk_data->clk_num; i++) {
+		struct clk *clk;
+		const char *clk_name;
+
+		if (of_property_read_string_index(np, "clock-output-names",
+						  i, &clk_name)) {
+			break;
+		}
+
+		/*
+		 * If we read an empty clock name then the output is unused
+		 */
+		if (*clk_name == '\0')
+			continue;
+
+		clk = clk_register_flexgen(clk_name, parents, num_parents,
+					   reg, rlock, i, flex_flags);
+
+		if (IS_ERR(clk))
+			goto err;
+
+		clk_data->clks[i] = clk;
+	}
+
+	kfree(parents);
+	of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
+
+	return;
+
+err:
+	if (clk_data)
+		kfree(clk_data->clks);
+	kfree(clk_data);
+	kfree(parents);
+	kfree(rlock);
+}
+CLK_OF_DECLARE(flexgen, "st,flexgen", st_of_flexgen_setup);