clk: berlin: add driver for BG2x simple PLLs

This is a clock driver for the simple PLLs found on Berlin SoCs.
With repect to PLL registers and features, BG2/BG2CD and BG2Q are
slightly different, e.g. different allowed VCO dividers and bit
shifts.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

diff --git a/drivers/clk/berlin/Makefile b/drivers/clk/berlin/Makefile
index 5905733..9d3490e 100644 (file)
--- a/drivers/clk/berlin/Makefile
+++ b/drivers/clk/berlin/Makefile
@@ -1 +1 @@
-obj-y += berlin2-avpll.o
+obj-y += berlin2-avpll.o berlin2-pll.o

diff --git a/drivers/clk/berlin/berlin2-pll.c b/drivers/clk/berlin/berlin2-pll.c
new file mode 100644 (file)
index 0000000..bdc506b
--- /dev/null
+++ b/drivers/clk/berlin/berlin2-pll.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2014 Marvell Technology Group Ltd.
+ *
+ * Alexandre Belloni <alexandre.belloni@free-electrons.com>
+ * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.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-provider.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <asm/div64.h>
+
+#include "berlin2-div.h"
+
+struct berlin2_pll_map {
+       const u8 vcodiv[16];
+       u8 mult;
+       u8 fbdiv_shift;
+       u8 rfdiv_shift;
+       u8 divsel_shift;
+};
+
+struct berlin2_pll {
+       struct clk_hw hw;
+       void __iomem *base;
+       struct berlin2_pll_map map;
+};
+
+#define to_berlin2_pll(hw) container_of(hw, struct berlin2_pll, hw)
+
+#define SPLL_CTRL0     0x00
+#define SPLL_CTRL1     0x04
+#define SPLL_CTRL2     0x08
+#define SPLL_CTRL3     0x0c
+#define SPLL_CTRL4     0x10
+
+#define FBDIV_MASK     0x1ff
+#define RFDIV_MASK     0x1f
+#define DIVSEL_MASK    0xf
+
+/*
+ * The output frequency formula for the pll is:
+ * clkout = fbdiv / refdiv * parent / vcodiv
+ */
+static unsigned long
+berlin2_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
+{
+       struct berlin2_pll *pll = to_berlin2_pll(hw);
+       struct berlin2_pll_map *map = &pll->map;
+       u32 val, fbdiv, rfdiv, vcodivsel, vcodiv;
+       u64 rate = parent_rate;
+
+       val = readl_relaxed(pll->base + SPLL_CTRL0);
+       fbdiv = (val >> map->fbdiv_shift) & FBDIV_MASK;
+       rfdiv = (val >> map->rfdiv_shift) & RFDIV_MASK;
+       if (rfdiv == 0) {
+               pr_warn("%s has zero rfdiv\n", __clk_get_name(hw->clk));
+               rfdiv = 1;
+       }
+
+       val = readl_relaxed(pll->base + SPLL_CTRL1);
+       vcodivsel = (val >> map->divsel_shift) & DIVSEL_MASK;
+       vcodiv = map->vcodiv[vcodivsel];
+       if (vcodiv == 0) {
+               pr_warn("%s has zero vcodiv (index %d)\n",
+                       __clk_get_name(hw->clk), vcodivsel);
+               vcodiv = 1;
+       }
+
+       rate *= fbdiv * map->mult;
+       do_div(rate, rfdiv * vcodiv);
+
+       return (unsigned long)rate;
+}
+
+static const struct clk_ops berlin2_pll_ops = {
+       .recalc_rate    = berlin2_pll_recalc_rate,
+};
+
+struct clk * __init
+berlin2_pll_register(const struct berlin2_pll_map *map,
+                    void __iomem *base, const char *name,
+                    const char *parent_name, unsigned long flags)
+{
+       struct clk_init_data init;
+       struct berlin2_pll *pll;
+
+       pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+       if (!pll)
+               return ERR_PTR(-ENOMEM);
+
+       /* copy pll_map to allow __initconst */
+       memcpy(&pll->map, map, sizeof(*map));
+       pll->base = base;
+       pll->hw.init = &init;
+       init.name = name;
+       init.ops = &berlin2_pll_ops;
+       init.parent_names = &parent_name;
+       init.num_parents = 1;
+       init.flags = flags;
+
+       return clk_register(NULL, &pll->hw);
+}

diff --git a/drivers/clk/berlin/berlin2-pll.h b/drivers/clk/berlin/berlin2-pll.h
new file mode 100644 (file)
index 0000000..8831ce2
--- /dev/null
+++ b/drivers/clk/berlin/berlin2-pll.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2014 Marvell Technology Group Ltd.
+ *
+ * Alexandre Belloni <alexandre.belloni@free-electrons.com>
+ * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.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/>.
+ */
+#ifndef __BERLIN2_PLL_H
+#define __BERLIN2_PLL_H
+
+struct clk;
+
+struct berlin2_pll_map {
+       const u8 vcodiv[16];
+       u8 mult;
+       u8 fbdiv_shift;
+       u8 rfdiv_shift;
+       u8 divsel_shift;
+};
+
+struct clk * __init
+berlin2_pll_register(const struct berlin2_pll_map *map,
+                    void __iomem *base, const char *name,
+                    const char *parent_name, unsigned long flags);
+
+#endif /* __BERLIN2_PLL_H */