drivers/clk/versatile/clk-icst.c - kernel/quantenna - Git at Google

 /*
  * Driver for the ICST307 VCO clock found in the ARM Reference designs.
  * We wrap the custom interface from <asm/hardware/icst.h> into the generic
  * clock framework.
  *
  * Copyright (C) 2012-2015 Linus Walleij
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * TODO: when all ARM reference designs are migrated to generic clocks, the
  * ICST clock code from the ARM tree should probably be merged into this
  * file.
  */
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/export.h>
 #include <linux/err.h>
 #include <linux/clk-provider.h>
 #include <linux/io.h>
 #include <linux/regmap.h>
 #include <linux/mfd/syscon.h>

 #include "clk-icst.h"

 /* Magic unlocking token used on all Versatile boards */
 #define VERSATILE_LOCK_VAL	0xA05F

 /**
  * struct clk_icst - ICST VCO clock wrapper
  * @hw: corresponding clock hardware entry
  * @vcoreg: VCO register address
  * @lockreg: VCO lock register address
  * @params: parameters for this ICST instance
  * @rate: current rate
  */
 struct clk_icst {
 	struct clk_hw hw;
 	struct regmap *map;
 	u32 vcoreg_off;
 	u32 lockreg_off;
 	struct icst_params *params;
 	unsigned long rate;
 };

 #define to_icst(_hw) container_of(_hw, struct clk_icst, hw)

 /**
  * vco_get() - get ICST VCO settings from a certain ICST
  * @icst: the ICST clock to get
  * @vco: the VCO struct to return the value in
  */
 static int vco_get(struct clk_icst *icst, struct icst_vco *vco)
 {
 	u32 val;
 	int ret;

 	ret = regmap_read(icst->map, icst->vcoreg_off, &val);
 	if (ret)
 		return ret;
 	vco->v = val & 0x1ff;
 	vco->r = (val >> 9) & 0x7f;
 	vco->s = (val >> 16) & 03;
 	return 0;
 }

 /**
  * vco_set() - commit changes to an ICST VCO
  * @icst: the ICST clock to set
  * @vco: the VCO struct to set the changes from
  */
 static int vco_set(struct clk_icst *icst, struct icst_vco vco)
 {
 	u32 val;
 	int ret;

 	ret = regmap_read(icst->map, icst->vcoreg_off, &val);
 	if (ret)
 		return ret;

 	/* Mask the 18 bits used by the VCO */
 	val &= ~0x7ffff;
 	val |= vco.v | (vco.r << 9) | (vco.s << 16);

 	/* This magic unlocks the VCO so it can be controlled */
 	ret = regmap_write(icst->map, icst->lockreg_off, VERSATILE_LOCK_VAL);
 	if (ret)
 		return ret;
 	ret = regmap_write(icst->map, icst->vcoreg_off, val);
 	if (ret)
 		return ret;
 	/* This locks the VCO again */
 	ret = regmap_write(icst->map, icst->lockreg_off, 0);
 	if (ret)
 		return ret;
 	return 0;
 }

 static unsigned long icst_recalc_rate(struct clk_hw *hw,
 				      unsigned long parent_rate)
 {
 	struct clk_icst *icst = to_icst(hw);
 	struct icst_vco vco;
 	int ret;

 	if (parent_rate)
 		icst->params->ref = parent_rate;
 	ret = vco_get(icst, &vco);
 	if (ret) {
 		pr_err("ICST: could not get VCO setting\n");
 		return 0;
 	}
 	icst->rate = icst_hz(icst->params, vco);
 	return icst->rate;
 }

 static long icst_round_rate(struct clk_hw *hw, unsigned long rate,
 			    unsigned long *prate)
 {
 	struct clk_icst *icst = to_icst(hw);
 	struct icst_vco vco;

 	vco = icst_hz_to_vco(icst->params, rate);
 	return icst_hz(icst->params, vco);
 }

 static int icst_set_rate(struct clk_hw *hw, unsigned long rate,
 			 unsigned long parent_rate)
 {
 	struct clk_icst *icst = to_icst(hw);
 	struct icst_vco vco;

 	if (parent_rate)
 		icst->params->ref = parent_rate;
 	vco = icst_hz_to_vco(icst->params, rate);
 	icst->rate = icst_hz(icst->params, vco);
 	return vco_set(icst, vco);
 }

 static const struct clk_ops icst_ops = {
 	.recalc_rate = icst_recalc_rate,
 	.round_rate = icst_round_rate,
 	.set_rate = icst_set_rate,
 };

 static struct clk *icst_clk_setup(struct device *dev,
 				  const struct clk_icst_desc *desc,
 				  const char *name,
 				  const char *parent_name,
 				  struct regmap *map)
 {
 	struct clk *clk;
 	struct clk_icst *icst;
 	struct clk_init_data init;
 	struct icst_params *pclone;

 	icst = kzalloc(sizeof(struct clk_icst), GFP_KERNEL);
 	if (!icst) {
 		pr_err("could not allocate ICST clock!\n");
 		return ERR_PTR(-ENOMEM);
 	}

 	pclone = kmemdup(desc->params, sizeof(*pclone), GFP_KERNEL);
 	if (!pclone) {
 		kfree(icst);
 		pr_err("could not clone ICST params\n");
 		return ERR_PTR(-ENOMEM);
 	}

 	init.name = name;
 	init.ops = &icst_ops;
 	init.flags = 0;
 	init.parent_names = (parent_name ? &parent_name : NULL);
 	init.num_parents = (parent_name ? 1 : 0);
 	icst->map = map;
 	icst->hw.init = &init;
 	icst->params = pclone;
 	icst->vcoreg_off = desc->vco_offset;
 	icst->lockreg_off = desc->lock_offset;

 	clk = clk_register(dev, &icst->hw);
 	if (IS_ERR(clk)) {
 		kfree(pclone);
 		kfree(icst);
 	}

 	return clk;
 }

 struct clk *icst_clk_register(struct device *dev,
 			const struct clk_icst_desc *desc,
 			const char *name,
 			const char *parent_name,
 			void __iomem *base)
 {
 	struct regmap_config icst_regmap_conf = {
 		.reg_bits = 32,
 		.val_bits = 32,
 		.reg_stride = 4,
 	};
 	struct regmap *map;

 	map = regmap_init_mmio(dev, base, &icst_regmap_conf);
 	if (IS_ERR(map)) {
 		pr_err("could not initialize ICST regmap\n");
 		return ERR_CAST(map);
 	}
 	return icst_clk_setup(dev, desc, name, parent_name, map);
 }
 EXPORT_SYMBOL_GPL(icst_clk_register);

 #ifdef CONFIG_OF
 /*
  * In a device tree, an memory-mapped ICST clock appear as a child
  * of a syscon node. Assume this and probe it only as a child of a
  * syscon.
  */

 static const struct icst_params icst525_params = {
 	.vco_max	= ICST525_VCO_MAX_5V,
 	.vco_min	= ICST525_VCO_MIN,
 	.vd_min		= 8,
 	.vd_max		= 263,
 	.rd_min		= 3,
 	.rd_max		= 65,
 	.s2div		= icst525_s2div,
 	.idx2s		= icst525_idx2s,
 };

 static const struct icst_params icst307_params = {
 	.vco_max	= ICST307_VCO_MAX,
 	.vco_min	= ICST307_VCO_MIN,
 	.vd_min		= 4 + 8,
 	.vd_max		= 511 + 8,
 	.rd_min		= 1 + 2,
 	.rd_max		= 127 + 2,
 	.s2div		= icst307_s2div,
 	.idx2s		= icst307_idx2s,
 };

 static void __init of_syscon_icst_setup(struct device_node *np)
 {
 	struct device_node *parent;
 	struct regmap *map;
 	struct clk_icst_desc icst_desc;
 	const char *name = np->name;
 	const char *parent_name;
 	struct clk *regclk;

 	/* We do not release this reference, we are using it perpetually */
 	parent = of_get_parent(np);
 	if (!parent) {
 		pr_err("no parent node for syscon ICST clock\n");
 		return;
 	}
 	map = syscon_node_to_regmap(parent);
 	if (IS_ERR(map)) {
 		pr_err("no regmap for syscon ICST clock parent\n");
 		return;
 	}

 	if (of_property_read_u32(np, "vco-offset", &icst_desc.vco_offset)) {
 		pr_err("no VCO register offset for ICST clock\n");
 		return;
 	}
 	if (of_property_read_u32(np, "lock-offset", &icst_desc.lock_offset)) {
 		pr_err("no lock register offset for ICST clock\n");
 		return;
 	}

 	if (of_device_is_compatible(np, "arm,syscon-icst525"))
 		icst_desc.params = &icst525_params;
 	else if (of_device_is_compatible(np, "arm,syscon-icst307"))
 		icst_desc.params = &icst307_params;
 	else {
 		pr_err("unknown ICST clock %s\n", name);
 		return;
 	}

 	/* Parent clock name is not the same as node parent */
 	parent_name = of_clk_get_parent_name(np, 0);

 	regclk = icst_clk_setup(NULL, &icst_desc, name, parent_name, map);
 	if (IS_ERR(regclk)) {
 		pr_err("error setting up syscon ICST clock %s\n", name);
 		return;
 	}
 	of_clk_add_provider(np, of_clk_src_simple_get, regclk);
 	pr_debug("registered syscon ICST clock %s\n", name);
 }

 CLK_OF_DECLARE(arm_syscon_icst525_clk,
 	       "arm,syscon-icst525", of_syscon_icst_setup);
 CLK_OF_DECLARE(arm_syscon_icst307_clk,
 	       "arm,syscon-icst307", of_syscon_icst_setup);

 #endif
	/*
	* Driver for the ICST307 VCO clock found in the ARM Reference designs.
	* We wrap the custom interface from <asm/hardware/icst.h> into the generic
	* clock framework.
	*
	* Copyright (C) 2012-2015 Linus Walleij
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* TODO: when all ARM reference designs are migrated to generic clocks, the
	* ICST clock code from the ARM tree should probably be merged into this
	* file.
	*/
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/export.h>
	#include <linux/err.h>
	#include <linux/clk-provider.h>
	#include <linux/io.h>
	#include <linux/regmap.h>
	#include <linux/mfd/syscon.h>

	#include "clk-icst.h"

	/* Magic unlocking token used on all Versatile boards */
	#define VERSATILE_LOCK_VAL 0xA05F

	/**
	* struct clk_icst - ICST VCO clock wrapper
	* @hw: corresponding clock hardware entry
	* @vcoreg: VCO register address
	* @lockreg: VCO lock register address
	* @params: parameters for this ICST instance
	* @rate: current rate
	*/
	struct clk_icst {
	struct clk_hw hw;
	struct regmap *map;
	u32 vcoreg_off;
	u32 lockreg_off;
	struct icst_params *params;
	unsigned long rate;
	};

	#define to_icst(_hw) container_of(_hw, struct clk_icst, hw)

	/**
	* vco_get() - get ICST VCO settings from a certain ICST
	* @icst: the ICST clock to get
	* @vco: the VCO struct to return the value in
	*/
	static int vco_get(struct clk_icst icst, struct icst_vco vco)
	{
	u32 val;
	int ret;

	ret = regmap_read(icst->map, icst->vcoreg_off, &val);
	if (ret)
	return ret;
	vco->v = val & 0x1ff;
	vco->r = (val >> 9) & 0x7f;
	vco->s = (val >> 16) & 03;
	return 0;
	}

	/**
	* vco_set() - commit changes to an ICST VCO
	* @icst: the ICST clock to set
	* @vco: the VCO struct to set the changes from
	*/
	static int vco_set(struct clk_icst *icst, struct icst_vco vco)
	{
	u32 val;
	int ret;

	ret = regmap_read(icst->map, icst->vcoreg_off, &val);
	if (ret)
	return ret;

	/* Mask the 18 bits used by the VCO */
	val &= ~0x7ffff;
	val \|= vco.v \| (vco.r << 9) \| (vco.s << 16);

	/* This magic unlocks the VCO so it can be controlled */
	ret = regmap_write(icst->map, icst->lockreg_off, VERSATILE_LOCK_VAL);
	if (ret)
	return ret;
	ret = regmap_write(icst->map, icst->vcoreg_off, val);
	if (ret)
	return ret;
	/* This locks the VCO again */
	ret = regmap_write(icst->map, icst->lockreg_off, 0);
	if (ret)
	return ret;
	return 0;
	}

	static unsigned long icst_recalc_rate(struct clk_hw *hw,
	unsigned long parent_rate)
	{
	struct clk_icst *icst = to_icst(hw);
	struct icst_vco vco;
	int ret;

	if (parent_rate)
	icst->params->ref = parent_rate;
	ret = vco_get(icst, &vco);
	if (ret) {
	pr_err("ICST: could not get VCO setting\n");
	return 0;
	}
	icst->rate = icst_hz(icst->params, vco);
	return icst->rate;
	}

	static long icst_round_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long *prate)
	{
	struct clk_icst *icst = to_icst(hw);
	struct icst_vco vco;

	vco = icst_hz_to_vco(icst->params, rate);
	return icst_hz(icst->params, vco);
	}

	static int icst_set_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long parent_rate)
	{
	struct clk_icst *icst = to_icst(hw);
	struct icst_vco vco;

	if (parent_rate)
	icst->params->ref = parent_rate;
	vco = icst_hz_to_vco(icst->params, rate);
	icst->rate = icst_hz(icst->params, vco);
	return vco_set(icst, vco);
	}

	static const struct clk_ops icst_ops = {
	.recalc_rate = icst_recalc_rate,
	.round_rate = icst_round_rate,
	.set_rate = icst_set_rate,
	};

	static struct clk icst_clk_setup(struct device dev,
	const struct clk_icst_desc *desc,
	const char *name,
	const char *parent_name,
	struct regmap *map)
	{
	struct clk *clk;
	struct clk_icst *icst;
	struct clk_init_data init;
	struct icst_params *pclone;

	icst = kzalloc(sizeof(struct clk_icst), GFP_KERNEL);
	if (!icst) {
	pr_err("could not allocate ICST clock!\n");
	return ERR_PTR(-ENOMEM);
	}

	pclone = kmemdup(desc->params, sizeof(*pclone), GFP_KERNEL);
	if (!pclone) {
	kfree(icst);
	pr_err("could not clone ICST params\n");
	return ERR_PTR(-ENOMEM);
	}

	init.name = name;
	init.ops = &icst_ops;
	init.flags = 0;
	init.parent_names = (parent_name ? &parent_name : NULL);
	init.num_parents = (parent_name ? 1 : 0);
	icst->map = map;
	icst->hw.init = &init;
	icst->params = pclone;
	icst->vcoreg_off = desc->vco_offset;
	icst->lockreg_off = desc->lock_offset;

	clk = clk_register(dev, &icst->hw);
	if (IS_ERR(clk)) {
	kfree(pclone);
	kfree(icst);
	}

	return clk;
	}

	struct clk icst_clk_register(struct device dev,
	const struct clk_icst_desc *desc,
	const char *name,
	const char *parent_name,
	void __iomem *base)
	{
	struct regmap_config icst_regmap_conf = {
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = 4,
	};
	struct regmap *map;

	map = regmap_init_mmio(dev, base, &icst_regmap_conf);
	if (IS_ERR(map)) {
	pr_err("could not initialize ICST regmap\n");
	return ERR_CAST(map);
	}
	return icst_clk_setup(dev, desc, name, parent_name, map);
	}
	EXPORT_SYMBOL_GPL(icst_clk_register);

	#ifdef CONFIG_OF
	/*
	* In a device tree, an memory-mapped ICST clock appear as a child
	* of a syscon node. Assume this and probe it only as a child of a
	* syscon.
	*/

	static const struct icst_params icst525_params = {
	.vco_max = ICST525_VCO_MAX_5V,
	.vco_min = ICST525_VCO_MIN,
	.vd_min = 8,
	.vd_max = 263,
	.rd_min = 3,
	.rd_max = 65,
	.s2div = icst525_s2div,
	.idx2s = icst525_idx2s,
	};

	static const struct icst_params icst307_params = {
	.vco_max = ICST307_VCO_MAX,
	.vco_min = ICST307_VCO_MIN,
	.vd_min = 4 + 8,
	.vd_max = 511 + 8,
	.rd_min = 1 + 2,
	.rd_max = 127 + 2,
	.s2div = icst307_s2div,
	.idx2s = icst307_idx2s,
	};

	static void __init of_syscon_icst_setup(struct device_node *np)
	{
	struct device_node *parent;
	struct regmap *map;
	struct clk_icst_desc icst_desc;
	const char *name = np->name;
	const char *parent_name;
	struct clk *regclk;

	/* We do not release this reference, we are using it perpetually */
	parent = of_get_parent(np);
	if (!parent) {
	pr_err("no parent node for syscon ICST clock\n");
	return;
	}
	map = syscon_node_to_regmap(parent);
	if (IS_ERR(map)) {
	pr_err("no regmap for syscon ICST clock parent\n");
	return;
	}

	if (of_property_read_u32(np, "vco-offset", &icst_desc.vco_offset)) {
	pr_err("no VCO register offset for ICST clock\n");
	return;
	}
	if (of_property_read_u32(np, "lock-offset", &icst_desc.lock_offset)) {
	pr_err("no lock register offset for ICST clock\n");
	return;
	}

	if (of_device_is_compatible(np, "arm,syscon-icst525"))
	icst_desc.params = &icst525_params;
	else if (of_device_is_compatible(np, "arm,syscon-icst307"))
	icst_desc.params = &icst307_params;
	else {
	pr_err("unknown ICST clock %s\n", name);
	return;
	}

	/* Parent clock name is not the same as node parent */
	parent_name = of_clk_get_parent_name(np, 0);

	regclk = icst_clk_setup(NULL, &icst_desc, name, parent_name, map);
	if (IS_ERR(regclk)) {
	pr_err("error setting up syscon ICST clock %s\n", name);
	return;
	}
	of_clk_add_provider(np, of_clk_src_simple_get, regclk);
	pr_debug("registered syscon ICST clock %s\n", name);
	}

	CLK_OF_DECLARE(arm_syscon_icst525_clk,
	"arm,syscon-icst525", of_syscon_icst_setup);
	CLK_OF_DECLARE(arm_syscon_icst307_clk,
	"arm,syscon-icst307", of_syscon_icst_setup);

	#endif