arch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c - kernel/bruno - Git at Google

 /*
  * OMAP2xxx DVFS virtual clock functions
  *
  * Copyright (C) 2005-2008, 2012 Texas Instruments, Inc.
  * Copyright (C) 2004-2010 Nokia Corporation
  *
  * Contacts:
  * Richard Woodruff <r-woodruff2@ti.com>
  * Paul Walmsley
  *
  * Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
  * Gordon McNutt and RidgeRun, Inc.
  *
  * 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.
  *
  * XXX Some of this code should be replaceable by the upcoming OPP layer
  * code.  However, some notion of "rate set" is probably still necessary
  * for OMAP2xxx at least.  Rate sets should be generalized so they can be
  * used for any OMAP chip, not just OMAP2xxx.  In particular, Richard Woodruff
  * has in the past expressed a preference to use rate sets for OPP changes,
  * rather than dynamically recalculating the clock tree, so if someone wants
  * this badly enough to write the code to handle it, we should support it
  * as an option.
  */
 #undef DEBUG

 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/cpufreq.h>
 #include <linux/slab.h>

 #include "soc.h"
 #include "clock.h"
 #include "clock2xxx.h"
 #include "opp2xxx.h"
 #include "cm2xxx.h"
 #include "cm-regbits-24xx.h"
 #include "sdrc.h"
 #include "sram.h"

 const struct prcm_config *curr_prcm_set;
 const struct prcm_config *rate_table;

 /*
  * sys_ck_rate: the rate of the external high-frequency clock
  * oscillator on the board.  Set by the SoC-specific clock init code.
  * Once set during a boot, will not change.
  */
 static unsigned long sys_ck_rate;

 /**
  * omap2_table_mpu_recalc - just return the MPU speed
  * @clk: virt_prcm_set struct clk
  *
  * Set virt_prcm_set's rate to the mpu_speed field of the current PRCM set.
  */
 unsigned long omap2_table_mpu_recalc(struct clk_hw *clk,
 				     unsigned long parent_rate)
 {
 	return curr_prcm_set->mpu_speed;
 }

 /*
  * Look for a rate equal or less than the target rate given a configuration set.
  *
  * What's not entirely clear is "which" field represents the key field.
  * Some might argue L3-DDR, others ARM, others IVA. This code is simple and
  * just uses the ARM rates.
  */
 long omap2_round_to_table_rate(struct clk_hw *hw, unsigned long rate,
 			       unsigned long *parent_rate)
 {
 	const struct prcm_config *ptr;
 	long highest_rate;

 	highest_rate = -EINVAL;

 	for (ptr = rate_table; ptr->mpu_speed; ptr++) {
 		if (!(ptr->flags & cpu_mask))
 			continue;
 		if (ptr->xtal_speed != sys_ck_rate)
 			continue;

 		highest_rate = ptr->mpu_speed;

 		/* Can check only after xtal frequency check */
 		if (ptr->mpu_speed <= rate)
 			break;
 	}
 	return highest_rate;
 }

 /* Sets basic clocks based on the specified rate */
 int omap2_select_table_rate(struct clk_hw *hw, unsigned long rate,
 			    unsigned long parent_rate)
 {
 	u32 cur_rate, done_rate, bypass = 0;
 	const struct prcm_config *prcm;
 	unsigned long found_speed = 0;
 	unsigned long flags;

 	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
 		if (!(prcm->flags & cpu_mask))
 			continue;

 		if (prcm->xtal_speed != sys_ck_rate)
 			continue;

 		if (prcm->mpu_speed <= rate) {
 			found_speed = prcm->mpu_speed;
 			break;
 		}
 	}

 	if (!found_speed) {
 		printk(KERN_INFO "Could not set MPU rate to %luMHz\n",
 		       rate / 1000000);
 		return -EINVAL;
 	}

 	curr_prcm_set = prcm;
 	cur_rate = omap2xxx_clk_get_core_rate();

 	if (prcm->dpll_speed == cur_rate / 2) {
 		omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL, 1);
 	} else if (prcm->dpll_speed == cur_rate * 2) {
 		omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
 	} else if (prcm->dpll_speed != cur_rate) {
 		local_irq_save(flags);

 		if (prcm->dpll_speed == prcm->xtal_speed)
 			bypass = 1;

 		if ((prcm->cm_clksel2_pll & OMAP24XX_CORE_CLK_SRC_MASK) ==
 		    CORE_CLK_SRC_DPLL_X2)
 			done_rate = CORE_CLK_SRC_DPLL_X2;
 		else
 			done_rate = CORE_CLK_SRC_DPLL;

 		omap2xxx_cm_set_mod_dividers(prcm->cm_clksel_mpu,
 					     prcm->cm_clksel_dsp,
 					     prcm->cm_clksel_gfx,
 					     prcm->cm_clksel1_core,
 					     prcm->cm_clksel_mdm);

 		/* x2 to enter omap2xxx_sdrc_init_params() */
 		omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);

 		omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
 			       bypass);

 		omap2xxx_sdrc_init_params(omap2xxx_sdrc_dll_is_unlocked());
 		omap2xxx_sdrc_reprogram(done_rate, 0);

 		local_irq_restore(flags);
 	}

 	return 0;
 }

 /**
  * omap2xxx_clkt_vps_check_bootloader_rate - determine which of the rate
  * table sets matches the current CORE DPLL hardware rate
  *
  * Check the MPU rate set by bootloader.  Sets the 'curr_prcm_set'
  * global to point to the active rate set when found; otherwise, sets
  * it to NULL.  No return value;
  */
 void omap2xxx_clkt_vps_check_bootloader_rates(void)
 {
 	const struct prcm_config *prcm = NULL;
 	unsigned long rate;

 	rate = omap2xxx_clk_get_core_rate();
 	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
 		if (!(prcm->flags & cpu_mask))
 			continue;
 		if (prcm->xtal_speed != sys_ck_rate)
 			continue;
 		if (prcm->dpll_speed <= rate)
 			break;
 	}
 	curr_prcm_set = prcm;
 }

 /**
  * omap2xxx_clkt_vps_late_init - store a copy of the sys_ck rate
  *
  * Store a copy of the sys_ck rate for later use by the OMAP2xxx DVFS
  * code.  (The sys_ck rate does not -- or rather, must not -- change
  * during kernel runtime.)  Must be called after we have a valid
  * sys_ck rate, but before the virt_prcm_set clock rate is
  * recalculated.  No return value.
  */
 void omap2xxx_clkt_vps_late_init(void)
 {
 	struct clk *c;

 	c = clk_get(NULL, "sys_ck");
 	if (IS_ERR(c)) {
 		WARN(1, "could not locate sys_ck\n");
 	} else {
 		sys_ck_rate = clk_get_rate(c);
 		clk_put(c);
 	}
 }

 #ifdef CONFIG_OF
 #include <linux/clk-provider.h>
 #include <linux/clkdev.h>

 static const struct clk_ops virt_prcm_set_ops = {
 	.recalc_rate	= &omap2_table_mpu_recalc,
 	.set_rate	= &omap2_select_table_rate,
 	.round_rate	= &omap2_round_to_table_rate,
 };

 /**
  * omap2xxx_clkt_vps_init - initialize virt_prcm_set clock
  *
  * Does a manual init for the virtual prcm DVFS clock for OMAP2. This
  * function is called only from omap2 DT clock init, as the virtual
  * node is not modelled in the DT clock data.
  */
 void omap2xxx_clkt_vps_init(void)
 {
 	struct clk_init_data init = { NULL };
 	struct clk_hw_omap *hw = NULL;
 	struct clk *clk;
 	const char *parent_name = "mpu_ck";

 	omap2xxx_clkt_vps_late_init();
 	omap2xxx_clkt_vps_check_bootloader_rates();

 	hw = kzalloc(sizeof(*hw), GFP_KERNEL);
 	if (!hw)
 		goto cleanup;
 	init.name = "virt_prcm_set";
 	init.ops = &virt_prcm_set_ops;
 	init.parent_names = &parent_name;
 	init.num_parents = 1;

 	hw->hw.init = &init;

 	clk = clk_register(NULL, &hw->hw);
 	clkdev_create(clk, "cpufreq_ck", NULL);
 	return;
 cleanup:
 	kfree(hw);
 }
 #endif
	/*
	* OMAP2xxx DVFS virtual clock functions
	*
	* Copyright (C) 2005-2008, 2012 Texas Instruments, Inc.
	* Copyright (C) 2004-2010 Nokia Corporation
	*
	* Contacts:
	* Richard Woodruff <r-woodruff2@ti.com>
	* Paul Walmsley
	*
	* Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
	* Gordon McNutt and RidgeRun, Inc.
	*
	* 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.
	*
	* XXX Some of this code should be replaceable by the upcoming OPP layer
	* code. However, some notion of "rate set" is probably still necessary
	* for OMAP2xxx at least. Rate sets should be generalized so they can be
	* used for any OMAP chip, not just OMAP2xxx. In particular, Richard Woodruff
	* has in the past expressed a preference to use rate sets for OPP changes,
	* rather than dynamically recalculating the clock tree, so if someone wants
	* this badly enough to write the code to handle it, we should support it
	* as an option.
	*/
	#undef DEBUG

	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/clk.h>
	#include <linux/io.h>
	#include <linux/cpufreq.h>
	#include <linux/slab.h>

	#include "soc.h"
	#include "clock.h"
	#include "clock2xxx.h"
	#include "opp2xxx.h"
	#include "cm2xxx.h"
	#include "cm-regbits-24xx.h"
	#include "sdrc.h"
	#include "sram.h"

	const struct prcm_config *curr_prcm_set;
	const struct prcm_config *rate_table;

	/*
	* sys_ck_rate: the rate of the external high-frequency clock
	* oscillator on the board. Set by the SoC-specific clock init code.
	* Once set during a boot, will not change.
	*/
	static unsigned long sys_ck_rate;

	/**
	* omap2_table_mpu_recalc - just return the MPU speed
	* @clk: virt_prcm_set struct clk
	*
	* Set virt_prcm_set's rate to the mpu_speed field of the current PRCM set.
	*/
	unsigned long omap2_table_mpu_recalc(struct clk_hw *clk,
	unsigned long parent_rate)
	{
	return curr_prcm_set->mpu_speed;
	}

	/*
	* Look for a rate equal or less than the target rate given a configuration set.
	*
	* What's not entirely clear is "which" field represents the key field.
	* Some might argue L3-DDR, others ARM, others IVA. This code is simple and
	* just uses the ARM rates.
	*/
	long omap2_round_to_table_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long *parent_rate)
	{
	const struct prcm_config *ptr;
	long highest_rate;

	highest_rate = -EINVAL;

	for (ptr = rate_table; ptr->mpu_speed; ptr++) {
	if (!(ptr->flags & cpu_mask))
	continue;
	if (ptr->xtal_speed != sys_ck_rate)
	continue;

	highest_rate = ptr->mpu_speed;

	/* Can check only after xtal frequency check */
	if (ptr->mpu_speed <= rate)
	break;
	}
	return highest_rate;
	}

	/* Sets basic clocks based on the specified rate */
	int omap2_select_table_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long parent_rate)
	{
	u32 cur_rate, done_rate, bypass = 0;
	const struct prcm_config *prcm;
	unsigned long found_speed = 0;
	unsigned long flags;

	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
	if (!(prcm->flags & cpu_mask))
	continue;

	if (prcm->xtal_speed != sys_ck_rate)
	continue;

	if (prcm->mpu_speed <= rate) {
	found_speed = prcm->mpu_speed;
	break;
	}
	}

	if (!found_speed) {
	printk(KERN_INFO "Could not set MPU rate to %luMHz\n",
	rate / 1000000);
	return -EINVAL;
	}

	curr_prcm_set = prcm;
	cur_rate = omap2xxx_clk_get_core_rate();

	if (prcm->dpll_speed == cur_rate / 2) {
	omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL, 1);
	} else if (prcm->dpll_speed == cur_rate * 2) {
	omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
	} else if (prcm->dpll_speed != cur_rate) {
	local_irq_save(flags);

	if (prcm->dpll_speed == prcm->xtal_speed)
	bypass = 1;

	if ((prcm->cm_clksel2_pll & OMAP24XX_CORE_CLK_SRC_MASK) ==
	CORE_CLK_SRC_DPLL_X2)
	done_rate = CORE_CLK_SRC_DPLL_X2;
	else
	done_rate = CORE_CLK_SRC_DPLL;

	omap2xxx_cm_set_mod_dividers(prcm->cm_clksel_mpu,
	prcm->cm_clksel_dsp,
	prcm->cm_clksel_gfx,
	prcm->cm_clksel1_core,
	prcm->cm_clksel_mdm);

	/* x2 to enter omap2xxx_sdrc_init_params() */
	omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);

	omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
	bypass);

	omap2xxx_sdrc_init_params(omap2xxx_sdrc_dll_is_unlocked());
	omap2xxx_sdrc_reprogram(done_rate, 0);

	local_irq_restore(flags);
	}

	return 0;
	}

	/**
	* omap2xxx_clkt_vps_check_bootloader_rate - determine which of the rate
	* table sets matches the current CORE DPLL hardware rate
	*
	* Check the MPU rate set by bootloader. Sets the 'curr_prcm_set'
	* global to point to the active rate set when found; otherwise, sets
	* it to NULL. No return value;
	*/
	void omap2xxx_clkt_vps_check_bootloader_rates(void)
	{
	const struct prcm_config *prcm = NULL;
	unsigned long rate;

	rate = omap2xxx_clk_get_core_rate();
	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
	if (!(prcm->flags & cpu_mask))
	continue;
	if (prcm->xtal_speed != sys_ck_rate)
	continue;
	if (prcm->dpll_speed <= rate)
	break;
	}
	curr_prcm_set = prcm;
	}

	/**
	* omap2xxx_clkt_vps_late_init - store a copy of the sys_ck rate
	*
	* Store a copy of the sys_ck rate for later use by the OMAP2xxx DVFS
	* code. (The sys_ck rate does not -- or rather, must not -- change
	* during kernel runtime.) Must be called after we have a valid
	* sys_ck rate, but before the virt_prcm_set clock rate is
	* recalculated. No return value.
	*/
	void omap2xxx_clkt_vps_late_init(void)
	{
	struct clk *c;

	c = clk_get(NULL, "sys_ck");
	if (IS_ERR(c)) {
	WARN(1, "could not locate sys_ck\n");
	} else {
	sys_ck_rate = clk_get_rate(c);
	clk_put(c);
	}
	}

	#ifdef CONFIG_OF
	#include <linux/clk-provider.h>
	#include <linux/clkdev.h>

	static const struct clk_ops virt_prcm_set_ops = {
	.recalc_rate = &omap2_table_mpu_recalc,
	.set_rate = &omap2_select_table_rate,
	.round_rate = &omap2_round_to_table_rate,
	};

	/**
	* omap2xxx_clkt_vps_init - initialize virt_prcm_set clock
	*
	* Does a manual init for the virtual prcm DVFS clock for OMAP2. This
	* function is called only from omap2 DT clock init, as the virtual
	* node is not modelled in the DT clock data.
	*/
	void omap2xxx_clkt_vps_init(void)
	{
	struct clk_init_data init = { NULL };
	struct clk_hw_omap *hw = NULL;
	struct clk *clk;
	const char *parent_name = "mpu_ck";

	omap2xxx_clkt_vps_late_init();
	omap2xxx_clkt_vps_check_bootloader_rates();

	hw = kzalloc(sizeof(*hw), GFP_KERNEL);
	if (!hw)
	goto cleanup;
	init.name = "virt_prcm_set";
	init.ops = &virt_prcm_set_ops;
	init.parent_names = &parent_name;
	init.num_parents = 1;

	hw->hw.init = &init;

	clk = clk_register(NULL, &hw->hw);
	clkdev_create(clk, "cpufreq_ck", NULL);
	return;
	cleanup:
	kfree(hw);
	}
	#endif