clk: at91: Port at91 DT clock code

Port at91 DT clock code from Linux 4.9-rc3.

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 254 insertions, 0 deletions

diff --git a/drivers/clk/at91/clk-programmable.c b/drivers/clk/at91/clk-programmable.c
new file mode 100644
index 0000000000..ddb18c0f7c
--- /dev/null
+++ b/drivers/clk/at91/clk-programmable.c
@@ -0,0 +1,254 @@
+/*
+ *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <common.h>
+#include <clock.h>
+#include <of.h>
+#include <io.h>
+#include <linux/list.h>
+#include <linux/clk.h>
+#include <linux/clk/at91_pmc.h>
+#include <mfd/syscon.h>
+#include <regmap.h>
+
+#include "pmc.h"
+
+#define PROG_SOURCE_MAX		5
+#define PROG_ID_MAX		7
+
+#define PROG_STATUS_MASK(id)	(1 << ((id) + 8))
+#define PROG_PRES_MASK		0x7
+#define PROG_PRES(layout, pckr)	((pckr >> layout->pres_shift) & PROG_PRES_MASK)
+#define PROG_MAX_RM9200_CSS	3
+
+struct clk_programmable_layout {
+	u8 pres_shift;
+	u8 css_mask;
+	u8 have_slck_mck;
+};
+
+struct clk_programmable {
+	struct clk clk;
+	struct regmap *regmap;
+	u8 id;
+	const struct clk_programmable_layout *layout;
+	const char *parent_names[PROG_SOURCE_MAX];
+};
+
+#define to_clk_programmable(clk) container_of(clk, struct clk_programmable, clk)
+
+static unsigned long clk_programmable_recalc_rate(struct clk *clk,
+						  unsigned long parent_rate)
+{
+	struct clk_programmable *prog = to_clk_programmable(clk);
+	unsigned int pckr;
+
+	regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr);
+
+	return parent_rate >> PROG_PRES(prog->layout, pckr);
+}
+
+static int clk_programmable_set_parent(struct clk *clk, u8 index)
+{
+	struct clk_programmable *prog = to_clk_programmable(clk);
+	const struct clk_programmable_layout *layout = prog->layout;
+	unsigned int mask = layout->css_mask;
+	unsigned int pckr = index;
+
+	if (layout->have_slck_mck)
+		mask |= AT91_PMC_CSSMCK_MCK;
+
+	if (index > layout->css_mask) {
+		if (index > PROG_MAX_RM9200_CSS && !layout->have_slck_mck)
+			return -EINVAL;
+
+		pckr |= AT91_PMC_CSSMCK_MCK;
+	}
+
+	regmap_write_bits(prog->regmap, AT91_PMC_PCKR(prog->id), mask, pckr);
+
+	return 0;
+}
+
+static int clk_programmable_get_parent(struct clk *clk)
+{
+	struct clk_programmable *prog = to_clk_programmable(clk);
+	const struct clk_programmable_layout *layout = prog->layout;
+	unsigned int pckr;
+	u8 ret;
+
+	regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr);
+
+	ret = pckr & layout->css_mask;
+
+	if (layout->have_slck_mck && (pckr & AT91_PMC_CSSMCK_MCK) && !ret)
+		ret = PROG_MAX_RM9200_CSS + 1;
+
+	return ret;
+}
+
+static int clk_programmable_set_rate(struct clk *clk, unsigned long rate,
+				     unsigned long parent_rate)
+{
+	struct clk_programmable *prog = to_clk_programmable(clk);
+	const struct clk_programmable_layout *layout = prog->layout;
+	unsigned long div = parent_rate / rate;
+	unsigned int pckr;
+	int shift = 0;
+
+	regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr);
+
+	if (!div)
+		return -EINVAL;
+
+	shift = fls(div) - 1;
+
+	if (div != (1 << shift))
+		return -EINVAL;
+
+	if (shift >= PROG_PRES_MASK)
+		return -EINVAL;
+
+	regmap_write_bits(prog->regmap, AT91_PMC_PCKR(prog->id),
+			   PROG_PRES_MASK << layout->pres_shift,
+			   shift << layout->pres_shift);
+
+	return 0;
+}
+
+static const struct clk_ops programmable_ops = {
+	.recalc_rate = clk_programmable_recalc_rate,
+	.get_parent = clk_programmable_get_parent,
+	.set_parent = clk_programmable_set_parent,
+	.set_rate = clk_programmable_set_rate,
+};
+
+static struct clk *
+at91_clk_register_programmable(struct regmap *regmap,
+			       const char *name, const char **parent_names,
+			       u8 num_parents, u8 id,
+			       const struct clk_programmable_layout *layout)
+{
+	struct clk_programmable *prog;
+	int ret;
+
+	if (id > PROG_ID_MAX)
+		return ERR_PTR(-EINVAL);
+
+	prog = kzalloc(sizeof(*prog), GFP_KERNEL);
+	if (!prog)
+		return ERR_PTR(-ENOMEM);
+
+	prog->clk.name = name;
+	prog->clk.ops = &programmable_ops;
+	memcpy(prog->parent_names, parent_names,
+	       num_parents * sizeof(prog->parent_names[0]));
+	prog->clk.parent_names = &prog->parent_names[0];
+	prog->clk.num_parents = num_parents;
+	/* init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; */
+
+	prog->id = id;
+	prog->layout = layout;
+	prog->regmap = regmap;
+
+	ret = clk_register(&prog->clk);
+	if (ret) {
+		kfree(prog);
+		return ERR_PTR(ret);
+	}
+
+	return &prog->clk;
+}
+
+static const struct clk_programmable_layout at91rm9200_programmable_layout = {
+	.pres_shift = 2,
+	.css_mask = 0x3,
+	.have_slck_mck = 0,
+};
+
+static const struct clk_programmable_layout at91sam9g45_programmable_layout = {
+	.pres_shift = 2,
+	.css_mask = 0x3,
+	.have_slck_mck = 1,
+};
+
+static const struct clk_programmable_layout at91sam9x5_programmable_layout = {
+	.pres_shift = 4,
+	.css_mask = 0x7,
+	.have_slck_mck = 0,
+};
+
+static int
+of_at91_clk_prog_setup(struct device_node *np,
+		       const struct clk_programmable_layout *layout)
+{
+	int num;
+	u32 id;
+	struct clk *clk;
+	unsigned int num_parents;
+	const char *parent_names[PROG_SOURCE_MAX];
+	const char *name;
+	struct device_node *progclknp;
+	struct regmap *regmap;
+
+	num_parents = of_clk_get_parent_count(np);
+	if (num_parents == 0 || num_parents > PROG_SOURCE_MAX)
+		return -EINVAL;
+
+	of_clk_parent_fill(np, parent_names, num_parents);
+
+	num = of_get_child_count(np);
+	if (!num || num > (PROG_ID_MAX + 1))
+		return -EINVAL;
+
+	regmap = syscon_node_to_regmap(of_get_parent(np));
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	for_each_child_of_node(np, progclknp) {
+		if (of_property_read_u32(progclknp, "reg", &id))
+			continue;
+
+		if (of_property_read_string(np, "clock-output-names", &name))
+			name = progclknp->name;
+
+		clk = at91_clk_register_programmable(regmap, name,
+						     parent_names, num_parents,
+						     id, layout);
+		if (IS_ERR(clk))
+			continue;
+
+		of_clk_add_provider(progclknp, of_clk_src_simple_get, clk);
+	}
+
+	return 0;
+}
+
+
+static void __init of_at91rm9200_clk_prog_setup(struct device_node *np)
+{
+	of_at91_clk_prog_setup(np, &at91rm9200_programmable_layout);
+}
+CLK_OF_DECLARE(at91rm9200_clk_prog, "atmel,at91rm9200-clk-programmable",
+	       of_at91rm9200_clk_prog_setup);
+
+static int of_at91sam9g45_clk_prog_setup(struct device_node *np)
+{
+	return of_at91_clk_prog_setup(np, &at91sam9g45_programmable_layout);
+}
+CLK_OF_DECLARE(at91sam9g45_clk_prog, "atmel,at91sam9g45-clk-programmable",
+	       of_at91sam9g45_clk_prog_setup);
+
+static int of_at91sam9x5_clk_prog_setup(struct device_node *np)
+{
+	return of_at91_clk_prog_setup(np, &at91sam9x5_programmable_layout);
+}
+CLK_OF_DECLARE(at91sam9x5_clk_prog, "atmel,at91sam9x5-clk-programmable",
+	       of_at91sam9x5_clk_prog_setup);