From ac7d7419fb795308444afbde5b03ffa8b2aa3623 Mon Sep 17 00:00:00 2001
From: Heiko Stuebner <heiko@sntech.de>
Date: Tue, 27 Dec 2016 00:00:38 +0100
Subject: [PATCH 1/2] clk: rockchip: add a clock-type for muxes based in the
 grf

Rockchip socs often have some tiny number of muxes not controlled from
the core clock controller but through bits set in the general register
files. Add a clock-type that can control these as well, so that we
don't need to work around them being absent.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
Hi Elaine,

these two patches showcase how I'd think the tiny amount of grf-based clocks
is handled best. I did some reparenting tests with the aclk_vcodec_pre
from the second patch, so am pretty confident that it should work as expected.

If noone complains, I plan to apply these two for 4.11 so your rk3328 clock-
controller can build on top of these.

 drivers/clk/rockchip/Makefile     |   1 +
 drivers/clk/rockchip/clk-muxgrf.c | 102 ++++++++++++++++++++++++++++++++++++++
 drivers/clk/rockchip/clk.c        |   7 +++
 drivers/clk/rockchip/clk.h        |  21 ++++++++
 4 files changed, 131 insertions(+)
 create mode 100644 drivers/clk/rockchip/clk-muxgrf.c

diff --git a/drivers/clk/rockchip/Makefile b/drivers/clk/rockchip/Makefile
index 16e098c..a43a54d 100644
--- a/drivers/clk/rockchip/Makefile
+++ b/drivers/clk/rockchip/Makefile
@@ -8,6 +8,7 @@ obj-y	+= clk-pll.o
 obj-y	+= clk-cpu.o
 obj-y	+= clk-inverter.o
 obj-y	+= clk-mmc-phase.o
+obj-y	+= clk-muxgrf.o
 obj-y	+= clk-ddr.o
 obj-$(CONFIG_RESET_CONTROLLER)	+= softrst.o
 
diff --git a/drivers/clk/rockchip/clk-muxgrf.c b/drivers/clk/rockchip/clk-muxgrf.c
new file mode 100644
index 0000000..4f29118
--- /dev/null
+++ b/drivers/clk/rockchip/clk-muxgrf.c
@@ -0,0 +1,102 @@
+/*
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that 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.
+ */
+
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/regmap.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include "clk.h"
+
+struct rockchip_muxgrf_clock {
+	struct clk_hw		hw;
+	struct regmap		*regmap;
+	u32			reg;
+	u32			shift;
+	u32			width;
+	int			flags;
+};
+
+#define to_muxgrf_clock(_hw) container_of(_hw, struct rockchip_muxgrf_clock, hw)
+
+static u8 rockchip_muxgrf_get_parent(struct clk_hw *hw)
+{
+	struct rockchip_muxgrf_clock *mux = to_muxgrf_clock(hw);
+	unsigned int mask = GENMASK(mux->width - 1, 0);
+	unsigned int val;
+
+	regmap_read(mux->regmap, mux->reg, &val);
+
+	val >>= mux->shift;
+	val &= mask;
+
+	return val;
+}
+
+static int rockchip_muxgrf_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct rockchip_muxgrf_clock *mux = to_muxgrf_clock(hw);
+	unsigned int mask = GENMASK(mux->width + mux->shift - 1, mux->shift);
+	unsigned int val;
+
+	val = index;
+	val <<= mux->shift;
+
+	if (mux->flags & CLK_MUX_HIWORD_MASK)
+		return regmap_write(mux->regmap, mux->reg, val | (mask << 16));
+	else
+		return regmap_update_bits(mux->regmap, mux->reg, mask, val);
+}
+
+static const struct clk_ops rockchip_muxgrf_clk_ops = {
+	.get_parent = rockchip_muxgrf_get_parent,
+	.set_parent = rockchip_muxgrf_set_parent,
+	.determine_rate = __clk_mux_determine_rate,
+};
+
+struct clk *rockchip_clk_register_muxgrf(const char *name,
+				const char *const *parent_names, u8 num_parents,
+				int flags, struct regmap *regmap, int reg,
+				int shift, int width, int mux_flags)
+{
+	struct rockchip_muxgrf_clock *muxgrf_clock;
+	struct clk_init_data init;
+	struct clk *clk;
+
+	if (IS_ERR(regmap)) {
+		pr_err("%s: regmap not available\n", __func__);
+		return ERR_PTR(-ENOTSUPP);
+	}
+
+	muxgrf_clock = kmalloc(sizeof(*muxgrf_clock), GFP_KERNEL);
+	if (!muxgrf_clock)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.flags = flags;
+	init.num_parents = num_parents;
+	init.parent_names = parent_names;
+	init.ops = &rockchip_muxgrf_clk_ops;
+
+	muxgrf_clock->hw.init = &init;
+	muxgrf_clock->regmap = regmap;
+	muxgrf_clock->reg = reg;
+	muxgrf_clock->shift = shift;
+	muxgrf_clock->width = width;
+	muxgrf_clock->flags = mux_flags;
+
+	clk = clk_register(NULL, &muxgrf_clock->hw);
+	if (IS_ERR(clk))
+		kfree(muxgrf_clock);
+
+	return clk;
+}
diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
index b886be3..3abcbf4 100644
--- a/drivers/clk/rockchip/clk.c
+++ b/drivers/clk/rockchip/clk.c
@@ -417,6 +417,13 @@ void __init rockchip_clk_register_branches(
 				list->mux_shift, list->mux_width,
 				list->mux_flags, &ctx->lock);
 			break;
+		case branch_muxgrf:
+			clk = rockchip_clk_register_muxgrf(list->name,
+				list->parent_names, list->num_parents,
+				flags, ctx->grf, list->muxdiv_offset,
+				list->mux_shift, list->mux_width,
+				list->mux_flags);
+			break;
 		case branch_divider:
 			if (list->div_table)
 				clk = clk_register_divider_table(NULL,
diff --git a/drivers/clk/rockchip/clk.h b/drivers/clk/rockchip/clk.h
index d67eecc..58be202 100644
--- a/drivers/clk/rockchip/clk.h
+++ b/drivers/clk/rockchip/clk.h
@@ -317,11 +317,17 @@ struct clk *rockchip_clk_register_inverter(const char *name,
 				void __iomem *reg, int shift, int flags,
 				spinlock_t *lock);
 
+struct clk *rockchip_clk_register_muxgrf(const char *name,
+				const char *const *parent_names, u8 num_parents,
+				int flags, struct regmap *grf, int reg,
+				int shift, int width, int mux_flags);
+
 #define PNAME(x) static const char *const x[] __initconst
 
 enum rockchip_clk_branch_type {
 	branch_composite,
 	branch_mux,
+	branch_muxgrf,
 	branch_divider,
 	branch_fraction_divider,
 	branch_gate,
@@ -551,6 +557,21 @@ struct rockchip_clk_branch {
 		.gate_offset	= -1,				\
 	}
 
+#define MUXGRF(_id, cname, pnames, f, o, s, w, mf)		\
+	{							\
+		.id		= _id,				\
+		.branch_type	= branch_muxgrf,		\
+		.name		= cname,			\
+		.parent_names	= pnames,			\
+		.num_parents	= ARRAY_SIZE(pnames),		\
+		.flags		= f,				\
+		.muxdiv_offset	= o,				\
+		.mux_shift	= s,				\
+		.mux_width	= w,				\
+		.mux_flags	= mf,				\
+		.gate_offset	= -1,				\
+	}
+
 #define DIV(_id, cname, pname, f, o, s, w, df)			\
 	{							\
 		.id		= _id,				\
-- 
2.10.2

