clk: meson: Add support for Meson clock controller

This patchset adds the infrastructure for registering and managing the
core clocks found on Amlogic MesonX SoCs. In particular:

- PLLs
- CPU clock
- Fixed rate clocks, fixed factor clocks, ...

Signed-off-by: Carlo Caione <carlo@endlessm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

1 files changed, 250 insertions, 0 deletions

diff --git a/drivers/clk/meson/clkc.c b/drivers/clk/meson/clkc.c
new file mode 100644
index 000000000000..b8c511c5e7a7
--- /dev/null
+++ b/drivers/clk/meson/clkc.c
@@ -0,0 +1,250 @@
+/*
+ * Copyright (c) 2015 Endless Mobile, Inc.
+ * Author: Carlo Caione <carlo@endlessm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/mfd/syscon.h>
+#include <linux/slab.h>
+
+#include "clkc.h"
+
+static DEFINE_SPINLOCK(clk_lock);
+
+static struct clk **clks;
+static struct clk_onecell_data clk_data;
+
+struct clk ** __init meson_clk_init(struct device_node *np,
+				   unsigned long nr_clks)
+{
+	clks = kcalloc(nr_clks, sizeof(*clks), GFP_KERNEL);
+	if (!clks)
+		return ERR_PTR(-ENOMEM);
+
+	clk_data.clks = clks;
+	clk_data.clk_num = nr_clks;
+	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
+
+	return clks;
+}
+
+static void meson_clk_add_lookup(struct clk *clk, unsigned int id)
+{
+	if (clks && id)
+		clks[id] = clk;
+}
+
+static struct clk * __init
+meson_clk_register_composite(const struct clk_conf *clk_conf,
+			     void __iomem *clk_base)
+{
+	struct clk *clk;
+	struct clk_mux *mux = NULL;
+	struct clk_divider *div = NULL;
+	struct clk_gate *gate = NULL;
+	const struct clk_ops *mux_ops = NULL;
+	const struct composite_conf *composite_conf;
+
+	composite_conf = clk_conf->conf.composite;
+
+	if (clk_conf->num_parents > 1) {
+		mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+		if (!mux)
+			return ERR_PTR(-ENOMEM);
+
+		mux->reg = clk_base + clk_conf->reg_off
+				+ composite_conf->mux_parm.reg_off;
+		mux->shift = composite_conf->mux_parm.shift;
+		mux->mask = BIT(composite_conf->mux_parm.width) - 1;
+		mux->flags = composite_conf->mux_flags;
+		mux->lock = &clk_lock;
+		mux->table = composite_conf->mux_table;
+		mux_ops = (composite_conf->mux_flags & CLK_MUX_READ_ONLY) ?
+			  &clk_mux_ro_ops : &clk_mux_ops;
+	}
+
+	if (MESON_PARM_APPLICABLE(&composite_conf->div_parm)) {
+		div = kzalloc(sizeof(*div), GFP_KERNEL);
+		if (!div) {
+			clk = ERR_PTR(-ENOMEM);
+			goto error;
+		}
+
+		div->reg = clk_base + clk_conf->reg_off
+				+ composite_conf->div_parm.reg_off;
+		div->shift = composite_conf->div_parm.shift;
+		div->width = composite_conf->div_parm.width;
+		div->lock = &clk_lock;
+		div->flags = composite_conf->div_flags;
+		div->table = composite_conf->div_table;
+	}
+
+	if (MESON_PARM_APPLICABLE(&composite_conf->gate_parm)) {
+		gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+		if (!gate) {
+			clk = ERR_PTR(-ENOMEM);
+			goto error;
+		}
+
+		gate->reg = clk_base + clk_conf->reg_off
+				+ composite_conf->div_parm.reg_off;
+		gate->bit_idx = composite_conf->gate_parm.shift;
+		gate->flags = composite_conf->gate_flags;
+		gate->lock = &clk_lock;
+	}
+
+	clk = clk_register_composite(NULL, clk_conf->clk_name,
+				    clk_conf->clks_parent,
+				    clk_conf->num_parents,
+				    mux ? &mux->hw : NULL, mux_ops,
+				    div ? &div->hw : NULL, &clk_divider_ops,
+				    gate ? &gate->hw : NULL, &clk_gate_ops,
+				    clk_conf->flags);
+	if (IS_ERR(clk))
+		goto error;
+
+	return clk;
+
+error:
+	kfree(gate);
+	kfree(div);
+	kfree(mux);
+
+	return clk;
+}
+
+static struct clk * __init
+meson_clk_register_fixed_factor(const struct clk_conf *clk_conf,
+				void __iomem *clk_base)
+{
+	struct clk *clk;
+	const struct fixed_fact_conf *fixed_fact_conf;
+	const struct parm *p;
+	unsigned int mult, div;
+	u32 reg;
+
+	fixed_fact_conf = &clk_conf->conf.fixed_fact;
+
+	mult = clk_conf->conf.fixed_fact.mult;
+	div = clk_conf->conf.fixed_fact.div;
+
+	if (!mult) {
+		mult = 1;
+		p = &fixed_fact_conf->mult_parm;
+		if (MESON_PARM_APPLICABLE(p)) {
+			reg = readl(clk_base + clk_conf->reg_off + p->reg_off);
+			mult = PARM_GET(p->width, p->shift, reg);
+		}
+	}
+
+	if (!div) {
+		div = 1;
+		p = &fixed_fact_conf->div_parm;
+		if (MESON_PARM_APPLICABLE(p)) {
+			reg = readl(clk_base + clk_conf->reg_off + p->reg_off);
+			mult = PARM_GET(p->width, p->shift, reg);
+		}
+	}
+
+	clk = clk_register_fixed_factor(NULL,
+			clk_conf->clk_name,
+			clk_conf->clks_parent[0],
+			clk_conf->flags,
+			mult, div);
+
+	return clk;
+}
+
+static struct clk * __init
+meson_clk_register_fixed_rate(const struct clk_conf *clk_conf,
+			      void __iomem *clk_base)
+{
+	struct clk *clk;
+	const struct fixed_rate_conf *fixed_rate_conf;
+	const struct parm *r;
+	unsigned long rate;
+	u32 reg;
+
+	fixed_rate_conf = &clk_conf->conf.fixed_rate;
+	rate = fixed_rate_conf->rate;
+
+	if (!rate) {
+		r = &fixed_rate_conf->rate_parm;
+		reg = readl(clk_base + clk_conf->reg_off + r->reg_off);
+		rate = PARM_GET(r->width, r->shift, reg);
+	}
+
+	rate *= 1000000;
+
+	clk = clk_register_fixed_rate(NULL,
+			clk_conf->clk_name,
+			clk_conf->num_parents
+				? clk_conf->clks_parent[0] : NULL,
+			clk_conf->flags, rate);
+
+	return clk;
+}
+
+void __init meson_clk_register_clks(const struct clk_conf *clk_confs,
+				    size_t nr_confs,
+				    void __iomem *clk_base)
+{
+	unsigned int i;
+	struct clk *clk = NULL;
+
+	for (i = 0; i < nr_confs; i++) {
+		const struct clk_conf *clk_conf = &clk_confs[i];
+
+		switch (clk_conf->clk_type) {
+		case CLK_FIXED_RATE:
+			clk = meson_clk_register_fixed_rate(clk_conf,
+							    clk_base);
+			break;
+		case CLK_FIXED_FACTOR:
+			clk = meson_clk_register_fixed_factor(clk_conf,
+							      clk_base);
+			break;
+		case CLK_COMPOSITE:
+			clk = meson_clk_register_composite(clk_conf,
+							   clk_base);
+			break;
+		case CLK_CPU:
+			clk = meson_clk_register_cpu(clk_conf, clk_base,
+						     &clk_lock);
+			break;
+		case CLK_PLL:
+			clk = meson_clk_register_pll(clk_conf, clk_base,
+						     &clk_lock);
+			break;
+		default:
+			clk = NULL;
+		}
+
+		if (!clk) {
+			pr_err("%s: unknown clock type %d\n", __func__,
+			       clk_conf->clk_type);
+			continue;
+		}
+
+		if (IS_ERR(clk)) {
+			pr_warn("%s: Unable to create %s clock\n", __func__,
+				clk_conf->clk_name);
+			continue;
+		}
+
+		meson_clk_add_lookup(clk, clk_conf->clk_id);
+	}
+}