[PATCH 1/5] clk: berlin: add support for clocks

[Alexandre Belloni]

Add support for clocks having their own register set.

Signed-off-by: Alexandre Belloni <alexandre.belloni at free-electrons.com>
---
 drivers/clk/berlin/Makefile |   2 +-
 drivers/clk/berlin/clk.c    | 132 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 133 insertions(+), 1 deletion(-)
 create mode 100644 drivers/clk/berlin/clk.c

diff --git a/drivers/clk/berlin/Makefile b/drivers/clk/berlin/Makefile
index 94859513de90..9bfa58eaf25a 100644
--- a/drivers/clk/berlin/Makefile
+++ b/drivers/clk/berlin/Makefile
@@ -1,4 +1,4 @@
-obj-y += pll.o
+obj-y += pll.o clk.o
 obj-$(CONFIG_MACH_BERLIN_BG2)   += pll-berlin2.o
 obj-$(CONFIG_MACH_BERLIN_BG2CD) += pll-berlin2.o
 obj-$(CONFIG_MACH_BERLIN_BG2Q)  += pll-berlin2q.o
diff --git a/drivers/clk/berlin/clk.c b/drivers/clk/berlin/clk.c
new file mode 100644
index 000000000000..a0e688e5bead
--- /dev/null
+++ b/drivers/clk/berlin/clk.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2014 Marvell Technology Group Ltd.
+ *
+ * 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/bitops.h>
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+#include "common.h"
+
+#define CLKEN		(1 << 0)
+#define CLKPLLSEL_MASK	7
+#define CLKPLLSEL_SHIFT	1
+#define CLKPLLSWITCH	(1 << 4)
+#define CLKSWITCH	(1 << 5)
+#define CLKD3SWITCH	(1 << 6)
+#define CLKSEL_MASK	7
+#define CLKSEL_SHIFT	7
+
+struct berlin_clk {
+	struct clk_hw hw;
+	void __iomem *base;
+};
+
+#define to_berlin_clk(hw)	container_of(hw, struct berlin_clk, hw)
+
+static u8 clk_div[] = {1, 2, 4, 6, 8, 12, 1, 1};
+
+static unsigned long berlin_clk_recalc_rate(struct clk_hw *hw,
+					unsigned long parent_rate)
+{
+	u32 val, divider;
+	struct berlin_clk *clk = to_berlin_clk(hw);
+
+	val = readl_relaxed(clk->base);
+	if (val & CLKD3SWITCH)
+		divider = 3;
+	else {
+		if (val & CLKSWITCH) {
+			val >>= CLKSEL_SHIFT;
+			val &= CLKSEL_MASK;
+			divider = clk_div[val];
+		} else
+			divider = 1;
+	}
+
+	return parent_rate / divider;
+}
+
+static u8 berlin_clk_get_parent(struct clk_hw *hw)
+{
+	u32 val;
+	struct berlin_clk *clk = to_berlin_clk(hw);
+
+	val = readl_relaxed(clk->base);
+	if (val & CLKPLLSWITCH) {
+		val >>= CLKPLLSEL_SHIFT;
+		val &= CLKPLLSEL_MASK;
+		return val;
+	}
+
+	return 0;
+}
+
+static const struct clk_ops berlin_clk_ops = {
+	.recalc_rate	= berlin_clk_recalc_rate,
+	.get_parent	= berlin_clk_get_parent,
+};
+
+static void __init berlin_clk_setup(struct device_node *np)
+{
+	struct clk_init_data init;
+	struct berlin_clk *bclk;
+	struct clk *clk;
+	const char **parent_names;
+	int nparents, i, ret;
+
+	bclk = kzalloc(sizeof(*bclk), GFP_KERNEL);
+	if (WARN_ON(!bclk))
+		return;
+
+	bclk->base = of_iomap(np, 0);
+	if (WARN_ON(!bclk->base))
+		goto exit;
+
+	nparents = of_clk_get_parent_count(np);
+	if (WARN_ON(!nparents))
+		goto exit;
+
+	parent_names = kzalloc((sizeof(char *) * nparents), GFP_KERNEL);
+	if (WARN_ON(!parent_names))
+		goto exit;
+
+	init.name = np->name;
+	init.ops = &berlin_clk_ops;
+	for (i = 0; i < nparents; i++) {
+		parent_names[i] = of_clk_get_parent_name(np, i);
+		if (!parent_names[i])
+			break;
+	}
+	init.parent_names = parent_names;
+	init.num_parents = i;
+
+	bclk->hw.init = &init;
+
+	clk = clk_register(NULL, &bclk->hw);
+	kfree(parent_names);
+	if (WARN_ON(IS_ERR(clk)))
+		goto exit;
+
+	ret = of_clk_add_provider(np, of_clk_src_simple_get, clk);
+	WARN_ON(ret);
+
+	return;
+exit:
+	kfree(bclk);
+}
+
+CLK_OF_DECLARE(berlin_clk, "marvell,berlin-clk", berlin_clk_setup);
-- 
1.9.1