clk: st: Support for PLLs inside ClockGenA(s)

The patch supports the c65/c32 type PLLs used by ClockGenA(s)

PLL clock : It includes support for all c65/c32 type PLLs
inside ClockGenA(s) : implemented as Fixed Parent / Fixed Rate clock,
with clock rate calculated reading H/w settings done at BOOT.

c65 PLLs have 2 outputs : HS and LS
c32 PLLs have 1-4 outputs : ODFx

Signed-off-by: Pankaj Dev <[e-mail]>
Signed-off-by: Gabriel Fernandez <[e-mail]>
Signed-off-by: Mike Turquette <[e-mail]>

drivers/clk/st/Makefile

···
-obj-y += clkgen-mux.o
+obj-y += clkgen-mux.o clkgen-pll.o

drivers/clk/st/clkgen-pll.c

···
+/*
+ * Copyright (C) 2014 STMicroelectronics (R&D) Limited
+ *
+ * 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.
+ *
+ */
+
+/*
+ * Authors:
+ * Stephen Gallimore <[e-mail]>,
+ * Pankaj Dev <[e-mail]>.
+ */
+
+#include <linux/slab.h>
+#include <linux/of_address.h>
+#include <linux/clk-provider.h>
+
+#include "clkgen.h"
+
+static DEFINE_SPINLOCK(clkgena_c32_odf_lock);
+
+/*
+ * Common PLL configuration register bits for PLL800 and PLL1600 C65
+ */
+#define C65_MDIV_PLL800_MASK	(0xff)
+#define C65_MDIV_PLL1600_MASK	(0x7)
+#define C65_NDIV_MASK		(0xff)
+#define C65_PDIV_MASK		(0x7)
+
+/*
+ * PLL configuration register bits for PLL3200 C32
+ */
+#define C32_NDIV_MASK (0xff)
+#define C32_IDF_MASK (0x7)
+#define C32_ODF_MASK (0x3f)
+#define C32_LDF_MASK (0x7f)
+
+#define C32_MAX_ODFS (4)
+
+struct clkgen_pll_data {
+	struct clkgen_field pdn_status;
+	struct clkgen_field locked_status;
+	struct clkgen_field mdiv;
+	struct clkgen_field ndiv;
+	struct clkgen_field pdiv;
+	struct clkgen_field idf;
+	struct clkgen_field ldf;
+	unsigned int num_odfs;
+	struct clkgen_field odf[C32_MAX_ODFS];
+	struct clkgen_field odf_gate[C32_MAX_ODFS];
+	const struct clk_ops *ops;
+};
+
+static const struct clk_ops st_pll1600c65_ops;
+static const struct clk_ops st_pll800c65_ops;
+static const struct clk_ops stm_pll3200c32_ops;
+static const struct clk_ops st_pll1200c32_ops;
+
+static struct clkgen_pll_data st_pll1600c65_ax = {
+	.pdn_status	= CLKGEN_FIELD(0x0, 0x1,			19),
+	.locked_status	= CLKGEN_FIELD(0x0, 0x1,			31),
+	.mdiv		= CLKGEN_FIELD(0x0, C65_MDIV_PLL1600_MASK,	0),
+	.ndiv		= CLKGEN_FIELD(0x0, C65_NDIV_MASK,		8),
+	.ops		= &st_pll1600c65_ops
+};
+
+static struct clkgen_pll_data st_pll800c65_ax = {
+	.pdn_status	= CLKGEN_FIELD(0x0,	0x1,			19),
+	.locked_status	= CLKGEN_FIELD(0x0,	0x1,			31),
+	.mdiv		= CLKGEN_FIELD(0x0,	C65_MDIV_PLL800_MASK,	0),
+	.ndiv		= CLKGEN_FIELD(0x0,	C65_NDIV_MASK,		8),
+	.pdiv		= CLKGEN_FIELD(0x0,	C65_PDIV_MASK,		16),
+	.ops		= &st_pll800c65_ops
+};
+
+static struct clkgen_pll_data st_pll3200c32_a1x_0 = {
+	.pdn_status	= CLKGEN_FIELD(0x0,	0x1,			31),
+	.locked_status	= CLKGEN_FIELD(0x4,	0x1,			31),
+	.ndiv		= CLKGEN_FIELD(0x0,	C32_NDIV_MASK,		0x0),
+	.idf		= CLKGEN_FIELD(0x4,	C32_IDF_MASK,		0x0),
+	.num_odfs = 4,
+	.odf =	{	CLKGEN_FIELD(0x54,	C32_ODF_MASK,		4),
+			CLKGEN_FIELD(0x54,	C32_ODF_MASK,		10),
+			CLKGEN_FIELD(0x54,	C32_ODF_MASK,		16),
+			CLKGEN_FIELD(0x54,	C32_ODF_MASK,		22) },
+	.odf_gate = {	CLKGEN_FIELD(0x54,	0x1,			0),
+			CLKGEN_FIELD(0x54,	0x1,			1),
+			CLKGEN_FIELD(0x54,	0x1,			2),
+			CLKGEN_FIELD(0x54,	0x1,			3) },
+	.ops		= &stm_pll3200c32_ops,
+};
+
+static struct clkgen_pll_data st_pll3200c32_a1x_1 = {
+	.pdn_status	= CLKGEN_FIELD(0xC,	0x1,			31),
+	.locked_status	= CLKGEN_FIELD(0x10,	0x1,			31),
+	.ndiv		= CLKGEN_FIELD(0xC,	C32_NDIV_MASK,		0x0),
+	.idf		= CLKGEN_FIELD(0x10,	C32_IDF_MASK,		0x0),
+	.num_odfs = 4,
+	.odf = {	CLKGEN_FIELD(0x58,	C32_ODF_MASK,		4),
+			CLKGEN_FIELD(0x58,	C32_ODF_MASK,		10),
+			CLKGEN_FIELD(0x58,	C32_ODF_MASK,		16),
+			CLKGEN_FIELD(0x58,	C32_ODF_MASK,		22) },
+	.odf_gate = {	CLKGEN_FIELD(0x58,	0x1,			0),
+			CLKGEN_FIELD(0x58,	0x1,			1),
+			CLKGEN_FIELD(0x58,	0x1,			2),
+			CLKGEN_FIELD(0x58,	0x1,			3) },
+	.ops		= &stm_pll3200c32_ops,
+};
+
+/**
+ * DOC: Clock Generated by PLL, rate set and enabled by bootloader
+ *
+ * Traits of this clock:
+ * prepare - clk_(un)prepare only ensures parent is (un)prepared
+ * enable - clk_enable/disable only ensures parent is enabled
+ * rate - rate is fixed. No clk_set_rate support
+ * parent - fixed parent.  No clk_set_parent support
+ */
+
+/**
+ * PLL clock that is integrated in the ClockGenA instances on the STiH415
+ * and STiH416.
+ *
+ * @hw: handle between common and hardware-specific interfaces.
+ * @type: PLL instance type.
+ * @regs_base: base of the PLL configuration register(s).
+ *
+ */
+struct clkgen_pll {
+	struct clk_hw		hw;
+	struct clkgen_pll_data	*data;
+	void __iomem		*regs_base;
+};
+
+#define to_clkgen_pll(_hw) container_of(_hw, struct clkgen_pll, hw)
+
+static int clkgen_pll_is_locked(struct clk_hw *hw)
+{
+	struct clkgen_pll *pll = to_clkgen_pll(hw);
+	u32 locked = CLKGEN_READ(pll, locked_status);
+
+	return !!locked;
+}
+
+static int clkgen_pll_is_enabled(struct clk_hw *hw)
+{
+	struct clkgen_pll *pll = to_clkgen_pll(hw);
+	u32 poweroff = CLKGEN_READ(pll, pdn_status);
+	return !poweroff;
+}
+
+unsigned long recalc_stm_pll800c65(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	struct clkgen_pll *pll = to_clkgen_pll(hw);
+	unsigned long mdiv, ndiv, pdiv;
+	unsigned long rate;
+	uint64_t res;
+
+	if (!clkgen_pll_is_enabled(hw) || !clkgen_pll_is_locked(hw))
+		return 0;
+
+	pdiv = CLKGEN_READ(pll, pdiv);
+	mdiv = CLKGEN_READ(pll, mdiv);
+	ndiv = CLKGEN_READ(pll, ndiv);
+
+	if (!mdiv)
+		mdiv++; /* mdiv=0 or 1 => MDIV=1 */
+
+	res = (uint64_t)2 * (uint64_t)parent_rate * (uint64_t)ndiv;
+	rate = (unsigned long)div64_u64(res, mdiv * (1 << pdiv));
+
+	pr_debug("%s:%s rate %lu\n", __clk_get_name(hw->clk), __func__, rate);
+
+	return rate;
+
+}
+
+unsigned long recalc_stm_pll1600c65(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	struct clkgen_pll *pll = to_clkgen_pll(hw);
+	unsigned long mdiv, ndiv;
+	unsigned long rate;
+
+	if (!clkgen_pll_is_enabled(hw) || !clkgen_pll_is_locked(hw))
+		return 0;
+
+	mdiv = CLKGEN_READ(pll, mdiv);
+	ndiv = CLKGEN_READ(pll, ndiv);
+
+	if (!mdiv)
+		mdiv = 1;
+
+	/* Note: input is divided by 1000 to avoid overflow */
+	rate = ((2 * (parent_rate / 1000) * ndiv) / mdiv) * 1000;
+
+	pr_debug("%s:%s rate %lu\n", __clk_get_name(hw->clk), __func__, rate);
+
+	return rate;
+}
+
+unsigned long recalc_stm_pll3200c32(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	struct clkgen_pll *pll = to_clkgen_pll(hw);
+	unsigned long ndiv, idf;
+	unsigned long rate = 0;
+
+	if (!clkgen_pll_is_enabled(hw) || !clkgen_pll_is_locked(hw))
+		return 0;
+
+	ndiv = CLKGEN_READ(pll, ndiv);
+	idf = CLKGEN_READ(pll, idf);
+
+	if (idf)
+		/* Note: input is divided to avoid overflow */
+		rate = ((2 * (parent_rate/1000) * ndiv) / idf) * 1000;
+
+	pr_debug("%s:%s rate %lu\n", __clk_get_name(hw->clk), __func__, rate);
+
+	return rate;
+}
+
+unsigned long recalc_stm_pll1200c32(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	struct clkgen_pll *pll = to_clkgen_pll(hw);
+	unsigned long odf, ldf, idf;
+	unsigned long rate;
+
+	if (!clkgen_pll_is_enabled(hw) || !clkgen_pll_is_locked(hw))
+		return 0;
+
+	odf = CLKGEN_READ(pll, odf[0]);
+	ldf = CLKGEN_READ(pll, ldf);
+	idf = CLKGEN_READ(pll, idf);
+
+	if (!idf) /* idf==0 means 1 */
+		idf = 1;
+	if (!odf) /* odf==0 means 1 */
+		odf = 1;
+
+	/* Note: input is divided by 1000 to avoid overflow */
+	rate = (((parent_rate / 1000) * ldf) / (odf * idf)) * 1000;
+
+	pr_debug("%s:%s rate %lu\n", __clk_get_name(hw->clk), __func__, rate);
+
+	return rate;
+}
+
+static const struct clk_ops st_pll1600c65_ops = {
+	.is_enabled	= clkgen_pll_is_enabled,
+	.recalc_rate	= recalc_stm_pll1600c65,
+};
+
+static const struct clk_ops st_pll800c65_ops = {
+	.is_enabled	= clkgen_pll_is_enabled,
+	.recalc_rate	= recalc_stm_pll800c65,
+};
+
+static const struct clk_ops stm_pll3200c32_ops = {
+	.is_enabled	= clkgen_pll_is_enabled,
+	.recalc_rate	= recalc_stm_pll3200c32,
+};
+
+static const struct clk_ops st_pll1200c32_ops = {
+	.is_enabled	= clkgen_pll_is_enabled,
+	.recalc_rate	= recalc_stm_pll1200c32,
+};
+
+static struct clk * __init clkgen_pll_register(const char *parent_name,
+				struct clkgen_pll_data	*pll_data,
+				void __iomem *reg,
+				const char *clk_name)
+{
+	struct clkgen_pll *pll;
+	struct clk *clk;
+	struct clk_init_data init;
+
+	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+	if (!pll)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = clk_name;
+	init.ops = pll_data->ops;
+
+	init.flags = CLK_IS_BASIC;
+	init.parent_names = &parent_name;
+	init.num_parents  = 1;
+
+	pll->data = pll_data;
+	pll->regs_base = reg;
+	pll->hw.init = &init;
+
+	clk = clk_register(NULL, &pll->hw);
+	if (IS_ERR(clk)) {
+		kfree(pll);
+		return clk;
+	}
+
+	pr_debug("%s: parent %s rate %lu\n",
+			__clk_get_name(clk),
+			__clk_get_name(clk_get_parent(clk)),
+			clk_get_rate(clk));
+
+	return clk;
+}
+
+static struct clk * __init clkgen_c65_lsdiv_register(const char *parent_name,
+						     const char *clk_name)
+{
+	struct clk *clk;
+
+	clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0, 1, 2);
+	if (IS_ERR(clk))
+		return clk;
+
+	pr_debug("%s: parent %s rate %lu\n",
+			__clk_get_name(clk),
+			__clk_get_name(clk_get_parent(clk)),
+			clk_get_rate(clk));
+	return clk;
+}
+
+static void __iomem * __init clkgen_get_register_base(
+				struct device_node *np)
+{
+	struct device_node *pnode;
+	void __iomem *reg = NULL;
+
+	pnode = of_get_parent(np);
+	if (!pnode)
+		return NULL;
+
+	reg = of_iomap(pnode, 0);
+
+	of_node_put(pnode);
+	return reg;
+}
+
+#define CLKGENAx_PLL0_OFFSET 0x0
+#define CLKGENAx_PLL1_OFFSET 0x4
+
+static void __init clkgena_c65_pll_setup(struct device_node *np)
+{
+	const int num_pll_outputs = 3;
+	struct clk_onecell_data *clk_data;
+	const char *parent_name;
+	void __iomem *reg;
+	const char *clk_name;
+
+	parent_name = of_clk_get_parent_name(np, 0);
+	if (!parent_name)
+		return;
+
+	reg = clkgen_get_register_base(np);
+	if (!reg)
+		return;
+
+	clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
+	if (!clk_data)
+		return;
+
+	clk_data->clk_num = num_pll_outputs;
+	clk_data->clks = kzalloc(clk_data->clk_num * sizeof(struct clk *),
+				 GFP_KERNEL);
+
+	if (!clk_data->clks)
+		goto err;
+
+	if (of_property_read_string_index(np, "clock-output-names",
+					  0, &clk_name))
+		goto err;
+
+	/*
+	 * PLL0 HS (high speed) output
+	 */
+	clk_data->clks[0] = clkgen_pll_register(parent_name,
+						&st_pll1600c65_ax,
+						reg + CLKGENAx_PLL0_OFFSET,
+						clk_name);
+
+	if (IS_ERR(clk_data->clks[0]))
+		goto err;
+
+	if (of_property_read_string_index(np, "clock-output-names",
+					  1, &clk_name))
+		goto err;
+
+	/*
+	 * PLL0 LS (low speed) output, which is a fixed divide by 2 of the
+	 * high speed output.
+	 */
+	clk_data->clks[1] = clkgen_c65_lsdiv_register(__clk_get_name
+						      (clk_data->clks[0]),
+						      clk_name);
+
+	if (IS_ERR(clk_data->clks[1]))
+		goto err;
+
+	if (of_property_read_string_index(np, "clock-output-names",
+					  2, &clk_name))
+		goto err;
+
+	/*
+	 * PLL1 output
+	 */
+	clk_data->clks[2] = clkgen_pll_register(parent_name,
+						&st_pll800c65_ax,
+						reg + CLKGENAx_PLL1_OFFSET,
+						clk_name);
+
+	if (IS_ERR(clk_data->clks[2]))
+		goto err;
+
+	of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
+	return;
+
+err:
+	kfree(clk_data->clks);
+	kfree(clk_data);
+}
+CLK_OF_DECLARE(clkgena_c65_plls,
+	       "st,clkgena-plls-c65", clkgena_c65_pll_setup);
+
+static struct clk * __init clkgen_odf_register(const char *parent_name,
+					       void * __iomem reg,
+					       struct clkgen_pll_data *pll_data,
+					       int odf,
+					       spinlock_t *odf_lock,
+					       const char *odf_name)
+{
+	struct clk *clk;
+	unsigned long flags;
+	struct clk_gate *gate;
+	struct clk_divider *div;
+
+	flags = CLK_GET_RATE_NOCACHE | CLK_SET_RATE_GATE;
+
+	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		return ERR_PTR(-ENOMEM);
+
+	gate->flags = CLK_GATE_SET_TO_DISABLE;
+	gate->reg = reg + pll_data->odf_gate[odf].offset;
+	gate->bit_idx = pll_data->odf_gate[odf].shift;
+	gate->lock = odf_lock;
+
+	div = kzalloc(sizeof(*div), GFP_KERNEL);
+	if (!div)
+		return ERR_PTR(-ENOMEM);
+
+	div->flags = CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ALLOW_ZERO;
+	div->reg = reg + pll_data->odf[odf].offset;
+	div->shift = pll_data->odf[odf].shift;
+	div->width = fls(pll_data->odf[odf].mask);
+	div->lock = odf_lock;
+
+	clk = clk_register_composite(NULL, odf_name, &parent_name, 1,
+				     NULL, NULL,
+				     &div->hw, &clk_divider_ops,
+				     &gate->hw, &clk_gate_ops,
+				     flags);
+	if (IS_ERR(clk))
+		return clk;
+
+	pr_debug("%s: parent %s rate %lu\n",
+			__clk_get_name(clk),
+			__clk_get_name(clk_get_parent(clk)),
+			clk_get_rate(clk));
+	return clk;
+}
+
+static struct of_device_id c32_pll_of_match[] = {
+	{
+		.compatible = "st,plls-c32-a1x-0",
+		.data = &st_pll3200c32_a1x_0,
+	},
+	{
+		.compatible = "st,plls-c32-a1x-1",
+		.data = &st_pll3200c32_a1x_1,
+	},
+	{}
+};
+
+static void __init clkgen_c32_pll_setup(struct device_node *np)
+{
+	const struct of_device_id *match;
+	struct clk *clk;
+	const char *parent_name, *pll_name;
+	void __iomem *pll_base;
+	int num_odfs, odf;
+	struct clk_onecell_data *clk_data;
+	struct clkgen_pll_data	*data;
+
+	match = of_match_node(c32_pll_of_match, np);
+	if (!match) {
+		pr_err("%s: No matching data\n", __func__);
+		return;
+	}
+
+	data = (struct clkgen_pll_data *) match->data;
+
+	parent_name = of_clk_get_parent_name(np, 0);
+	if (!parent_name)
+		return;
+
+	pll_base = clkgen_get_register_base(np);
+	if (!pll_base)
+		return;
+
+	clk = clkgen_pll_register(parent_name, data, pll_base, np->name);
+	if (IS_ERR(clk))
+		return;
+
+	pll_name = __clk_get_name(clk);
+
+	num_odfs = data->num_odfs;
+
+	clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
+	if (!clk_data)
+		return;
+
+	clk_data->clk_num = num_odfs;
+	clk_data->clks = kzalloc(clk_data->clk_num * sizeof(struct clk *),
+				 GFP_KERNEL);
+
+	if (!clk_data->clks)
+		goto err;
+
+	for (odf = 0; odf < num_odfs; odf++) {
+		struct clk *clk;
+		const char *clk_name;
+
+		if (of_property_read_string_index(np, "clock-output-names",
+						  odf, &clk_name))
+			return;
+
+		clk = clkgen_odf_register(pll_name, pll_base, data,
+				odf, &clkgena_c32_odf_lock, clk_name);
+		if (IS_ERR(clk))
+			goto err;
+
+		clk_data->clks[odf] = clk;
+	}
+
+	of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
+	return;
+
+err:
+	kfree(pll_name);
+	kfree(clk_data->clks);
+	kfree(clk_data);
+}
+CLK_OF_DECLARE(clkgen_c32_pll, "st,clkgen-plls-c32", clkgen_c32_pll_setup);

drivers/clk/st/clkgen.h

···
+/************************************************************************
+File  : Clock H/w specific Information
+
+Author: Pankaj Dev <[e-mail]>
+
+Copyright (C) 2014 STMicroelectronics
+************************************************************************/
+
+#ifndef __CLKGEN_INFO_H
+#define __CLKGEN_INFO_H
+
+struct clkgen_field {
+	unsigned int offset;
+	unsigned int mask;
+	unsigned int shift;
+};
+
+static inline unsigned long clkgen_read(void __iomem	*base,
+					  struct clkgen_field *field)
+{
+	return (readl(base + field->offset) >> field->shift) & field->mask;
+}
+
+
+static inline void clkgen_write(void __iomem *base, struct clkgen_field *field,
+				  unsigned long val)
+{
+	writel((readl(base + field->offset) &
+	       ~(field->mask << field->shift)) | (val << field->shift),
+	       base + field->offset);
+
+	return;
+}
+
+#define CLKGEN_FIELD(_offset, _mask, _shift) {		\
+				.offset	= _offset,	\
+				.mask	= _mask,	\
+				.shift	= _shift,	\
+				}
+
+#define CLKGEN_READ(pll, field) clkgen_read(pll->regs_base, \
+		&pll->data->field)
+
+#define CLKGEN_WRITE(pll, field, val) clkgen_write(pll->regs_base, \
+		&pll->data->field, val)
+
+#endif /*__CLKGEN_INFO_H*/
+