/*
* OMAP3/4 - specific DPLL control functions
*
* Copyright (C) 2009 Texas Instruments, Inc.
* Copyright (C) 2009 Nokia Corporation
*
* Written by Paul Walmsley
* Testing and integration fixes by Jouni Högander
*
* Parts of this code are based on code written by
* Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu
*
* 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.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/limits.h>
#include <linux/bitops.h>
#include <plat/cpu.h>
#include <plat/clock.h>
#include <plat/sram.h>
#include <asm/div64.h>
#include <asm/clkdev.h>
#include "clock.h"
#include "prm.h"
#include "prm-regbits-34xx.h"
#include "cm.h"
#include "cm-regbits-34xx.h"
/* CM_AUTOIDLE_PLL*.AUTO_* bit values */
#define DPLL_AUTOIDLE_DISABLE 0x0
#define DPLL_AUTOIDLE_LOW_POWER_STOP 0x1
#define MAX_DPLL_WAIT_TRIES 1000000
/* Private functions */
/* _omap3_dpll_write_clken - write clken_bits arg to a DPLL's enable bits */
static void _omap3_dpll_write_clken(struct clk *clk, u8 clken_bits)
{
const struct dpll_data *dd;
u32 v;
dd = clk->dpll_data;
v = __raw_readl(dd->control_reg);
v &= ~dd->enable_mask;
v |= clken_bits << __ffs(dd->enable_mask);
__raw_writel(v, dd->control_reg);
}
/* _omap3_wait_dpll_status: wait for a DPLL to enter a specific state */
static int _omap3_wait_dpll_status(struct clk *clk, u8 state)
{
const struct dpll_data *dd;
int i = 0;
int ret = -EINVAL;
dd = clk->dpll_data;
state <<= __ffs(dd->idlest_mask);
while (((__raw_readl(dd->idlest_reg) & dd->idlest_mask) != state) &&
i < MAX_DPLL_WAIT_TRIES) {
i++;
udelay(1);
}
if (i == MAX_DPLL_WAIT_TRIES) {
printk(KERN_ERR "clock: %s failed transition to '%s'\n",
clk->name, (state) ? "locked" : "bypassed");
} else {
pr_debug("clock: %s transition to '%s' in %d loops\n",
clk->name, (state) ? "locked" : "bypassed", i);
ret = 0;
}
return ret;
}
/* From 3430 TRM ES2 4.7.6.2 */
static u16 _omap3_dpll_compute_freqsel(struct clk *clk, u8 n)
{
unsigned long fint;
u16 f = 0;
fint = clk->dpll_data->clk_ref->rate / n;
pr_debug("clock: fint is %lu\n", fint);
if (fint >= 750000 && fint <= 1000000)
f = 0x3;
else if (fint > 1000000 && fint <= 1250000)
f = 0x4;
else if (fint > 1250000 && fint <= 1500000)
f = 0x5;
else if (fint > 1500000 && fint <= 1750000)
f = 0x6;
else if (fint > 1750000 && fint <= 2100000)
f = 0x7;
else if (fint > 7500000 && fint <= 10000000)
f = 0xB;
else if (fint > 10000000 && fint <= 12500000)
f = 0xC;
else if (fint > 12500000 && fint <= 15000000)
f = 0xD;
else if (fint > 15000000 && fint <= 17500000)
f = 0xE;
else if (fint > 17500000 && fint <= 21000000)
f = 0xF;
else
pr_debug("clock: unknown freqsel setting for %d\n", n);
return f;
}
/*
* _omap3_noncore_dpll_lock - instruct a DPLL to lock and wait for readiness
* @clk: pointer to a DPLL struct clk
*
* Instructs a non-CORE DPLL to lock. Waits for the DPLL to report
* readiness before returning. Will save and restore the DPLL's
* autoidle state across the enable, per the CDP code. If the DPLL
* locked successfully, return 0; if the DPLL did not lock in the time
* allotted, or DPLL3 was passed in, return -EINVAL.
*/
static int _omap3_noncore_dpll_lock(struct clk *clk)
{
u8 ai;
int r;
pr_debug("clock: locking DPLL %s\n", clk->name);
ai = omap3_dpll_autoidle_read(clk);
omap3_dpll_deny_idle(clk);
_omap3_dpll_write_clken(clk, DPLL_LOCKED);
r = _omap3_wait_dpll_status(clk, 1);
if (ai)
omap3_dpll_allow_idle(clk);
return r;
}
/*
* _omap3_noncore_dpll_bypass - instruct a DPLL to bypass and wait for readiness
* @clk: pointer to a DPLL struct clk
*
* Instructs a non-CORE DPLL to enter low-power bypass mode. In
* bypass mode, the DPLL's rate is set equal to its parent clock's
* rate. Waits for the DPLL to report readiness before returning.
* Will save and restore the DPLL's autoidle state across the enable,
* per the CDP code. If the DPLL entered bypass mode successfully,
* return 0; if the DPLL did not enter bypass in the time allotted, or
* DPLL3 was passed in, or the DPLL does not support low-power bypass,
* return -EINVAL.
*/
static int _omap3_noncore_dpll_bypass(struct clk *clk)
{
int r;
u8 ai;
if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS)))
return -EINVAL;
pr_debug("clock: configuring DPLL %s for low-power bypass\n",
clk->name);
ai = omap3_dpll_autoidle_read(clk);
_omap3_dpll_write_clken(clk, DPLL_LOW_POWER_BYPASS);
r = _omap3_wait_dpll_status(clk, 0);
if (ai)
omap3_dpll_allow_idle(clk);
else
omap3_dpll_deny_idle(clk);
return r;
}
/*
* _omap3_noncore_dpll_stop - instruct a DPLL to stop
* @clk: pointer to a DPLL struct clk
*
* Instructs a non-CORE DPLL to enter low-power stop. Will save and
* restore the DPLL's autoidle state across the stop, per the CDP
* code. If DPLL3 was passed in, or the DPLL does not support
* low-power stop, return -EINVAL; otherwise, return 0.
*/
static int _omap3_noncore_dpll_stop(struct clk *clk)
{
u8 ai;
if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_STOP)))
return -EINVAL;
pr_debug("clock: stopping DPLL %s\n", clk->name);
ai = omap3_dpll_autoidle_read(clk);
_omap3_dpll_write_clken(clk, DPLL_LOW_POWER_STOP);
if (ai)
omap3_dpll_allow_idle(clk);
else
omap3_dpll_deny_idle(clk);
return 0;
}
/*
* _omap3_noncore_dpll_program - set non-core DPLL M,N values directly
* @clk: struct clk * of DPLL to set
* @m: DPLL multiplier to set
* @n: DPLL divider to set
* @freqsel: FREQSEL value to set
*
* Program the DPLL with the supplied M, N values, and wait for the DPLL to
* lock.. Returns -EINVAL upon error, or 0 upon success.
*/
static int omap3_noncore_dpll_program(struct clk *clk, u16 m, u8 n, u16 freqsel)
{
struct dpll_data *dd = clk->dpll_data;
u32 v;
/* 3430 ES2 TRM: 4.7.6.9 DPLL Programming Sequence */
_omap3_noncore_dpll_bypass(clk);
/* Set jitter correction */
if (!cpu_is_omap44xx()) {
v = __raw_readl(dd->control_reg);
v &= ~dd->freqsel_mask;
v |= freqsel << __ffs(dd->freqsel_mask);
__raw_writel(v, dd->control_reg);
}
/* Set DPLL multiplier, divider */
v = __raw_readl(dd->mult_div1_reg);
v &= ~(dd->mult_mask | dd->div1_mask);
v |= m << __ffs(dd->mult_mask);
v |= (n - 1) << __ffs(dd->div1_mask);
__raw_writel(v, dd->mult_div1_reg);
/* We let the clock framework set the other output dividers later */
/* REVISIT: Set ramp-up delay? */
_omap3_noncore_dpll_lock(clk);
return 0;
}
/* Public functions */
/**
* omap3_dpll_recalc - recalculate DPLL rate
* @clk: DPLL struct clk
*
* Recalculate and propagate the DPLL rate.
*/
unsigned long omap3_dpll_recalc(struct clk *clk)
{
return omap2_get_dpll_rate(clk);
}
/* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */
/**
* omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
* @clk: pointer to a DPLL struct clk
*
* Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
* The choice of modes depends on the DPLL's programmed rate: if it is
* the same as the DPLL's parent clock, it will enter bypass;
* otherwise, it will enter lock. This code will wait for the DPLL to
* indicate readiness before returning, unless the DPLL takes too long
* to enter the target state. Intended to be used as the struct clk's
* enable function. If DPLL3 was passed in, or the DPLL does not
* support low-power stop, or if the DPLL took too long to enter
* bypass or lock, return -EINVAL; otherwise, return 0.
*/
int omap3_noncore_dpll_enable(struct clk *clk)
{
int r;
struct dpll_data *dd;
dd = clk->dpll_data;
if (!dd)
return -EINVAL;
if (clk->rate == dd->clk_bypass->rate) {
WARN_ON(clk->parent != dd->clk_bypass);
r = _omap3_noncore_dpll_bypass(clk);
} else {
WARN_ON(clk->parent != dd->clk_ref);
r = _omap3_noncore_dpll_lock(clk);
}
/*
*FIXME: this is dubious - if clk->rate has changed, what about
* propagating?
*/
if (!r)
clk->rate = omap2_get_dpll_rate(clk);
return r;
}
/**
* omap3_noncore_dpll_disable - instruct a DPLL to enter low-power stop
* @clk: pointer to a DPLL struct clk
*
* Instructs a non-CORE DPLL to enter low-power stop. This function is
* intended for use in struct clkops. No return value.
*/
void omap3_noncore_dpll_disable(struct clk *clk)
{
_omap3_noncore_dpll_stop(clk);
}
/* Non-CORE DPLL rate set code */
/**
* omap3_noncore_dpll_set_rate - set non-core DPLL rate
* @clk: struct clk * of DPLL to set
* @rate: rounded target rate
*
* Set the DPLL CLKOUT to the target rate. If the DPLL can enter
* low-power bypass, and the target rate is the bypass source clock
* rate, then configure the DPLL for bypass. Otherwise, round the
* target rate if it hasn't been done already, then program and lock
* the DPLL. Returns -EINVAL upon error, or 0 upon success.
*/
int omap3_noncore_dpll_set_rate(struct clk *clk, unsigned long rate)
{
struct clk *new_parent = NULL;
u16 freqsel = 0;
struct dpll_data *dd;
int ret;
if (!clk || !rate)
return -EINVAL;
dd = clk->dpll_data;
if (!dd)
return -EINVAL;
if (rate == omap2_get_dpll_rate(clk))
return 0;
/*
* Ensure both the bypass and ref clocks are enabled prior to
* doing anything; we need the bypass clock running to reprogram
* the DPLL.
*/
omap2_clk_enable(dd->clk_bypass);
omap2_clk_enable(dd->clk_ref);
if (dd->clk_bypass->rate == rate &&
(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS))) {
pr_debug("clock: %s: set rate: entering bypass.\n", clk->name);
ret = _omap3_noncore_dpll_bypass(clk);
if (!ret)
new_parent = dd->clk_bypass;
} else {
if (dd->last_rounded_rate != rate)
omap2_dpll_round_rate(clk, rate);
if (dd->last_rounded_rate == 0)
return -EINVAL;
/* No freqsel on OMAP4 */
if (!cpu_is_omap44xx()) {
freqsel = _omap3_dpll_compute_freqsel(clk,
dd->last_rounded_n);
if (!freqsel)
WARN_ON(1);
}
pr_debug("clock: %s: set rate: locking rate to %lu.\n",
clk->name, rate);
ret = omap3_noncore_dpll_program(clk, dd->last_rounded_m,
dd->last_rounded_n, freqsel);
if (!ret)
new_parent = dd->clk_ref;
}
if (!ret) {
/*
* Switch the parent clock in the heirarchy, and make sure
* that the new parent's usecount is correct. Note: we
* enable the new parent before disabling the old to avoid
* any unnecessary hardware disable->enable transitions.
*/
if (clk->usecount) {
omap2_clk_enable(new_parent);
omap2_clk_disable(clk->parent);
}
clk_reparent(clk, new_parent);
clk->rate = rate;
}
omap2_clk_disable(dd->clk_ref);
omap2_clk_disable(dd->clk_bypass);
return 0;
}
/* DPLL autoidle read/set code */
/**
* omap3_dpll_autoidle_read - read a DPLL's autoidle bits
* @clk: struct clk * of the DPLL to read
*
* Return the DPLL's autoidle bits, shifted down to bit 0. Returns
* -EINVAL if passed a null pointer or if the struct clk does not
* appear to refer to a DPLL.
*/
u32 omap3_dpll_autoidle_read(struct clk *clk)
{
const struct dpll_data *dd;
u32 v;
if (!clk || !clk->dpll_data)
return -EINVAL;
dd = clk->dpll_data;
v = __raw_readl(dd->autoidle_reg);
v &= dd->autoidle_mask;
v >>= __ffs(dd->autoidle_mask);
return v;
}
/**
* omap3_dpll_allow_idle - enable DPLL autoidle bits
* @clk: struct clk * of the DPLL to operate on
*
* Enable DPLL automatic idle control. This automatic idle mode
* switching takes effect only when the DPLL is locked, at least on
* OMAP3430. The DPLL will enter low-power stop when its downstream
* clocks are gated. No return value.
*/
void omap3_dpll_allow_idle(struct clk *clk)
{
const struct dpll_data *dd;
u32 v;
if (!clk || !clk->dpll_data)
return;
dd = clk->dpll_data;
/*
* REVISIT: CORE DPLL can optionally enter low-power bypass
* by writing 0x5 instead of 0x1. Add some mechanism to
* optionally enter this mode.
*/
v = __raw_readl(dd->autoidle_reg);
v &= ~dd->autoidle_mask;
v |= DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask);
__raw_writel(v, dd->autoidle_reg);
}
/**
* omap3_dpll_deny_idle - prevent DPLL from automatically idling
* @clk: struct clk * of the DPLL to operate on
*
* Disable DPLL automatic idle control. No return value.
*/
void omap3_dpll_deny_idle(struct clk *clk)
{
const struct dpll_data *dd;
u32 v;
if (!clk || !clk->dpll_data)
return;
dd = clk->dpll_data;
v = __raw_readl(dd->autoidle_reg);
v &= ~dd->autoidle_mask;
v |= DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask);
__raw_writel(v, dd->autoidle_reg);
}
/* Clock control for DPLL outputs */
/**
* omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate
* @clk: DPLL output struct clk
*
* Using parent clock DPLL data, look up DPLL state. If locked, set our
* rate to the dpll_clk * 2; otherwise, just use dpll_clk.
*/
unsigned long omap3_clkoutx2_recalc(struct clk *clk)
{
const struct dpll_data *dd;
unsigned long rate;
u32 v;
struct clk *pclk;
/* Walk up the parents of clk, looking for a DPLL */
pclk = clk->parent;
while (pclk && !pclk->dpll_data)
pclk = pclk->parent;
/* clk does not have a DPLL as a parent? */
WARN_ON(!pclk);
dd = pclk->dpll_data;
WARN_ON(!dd->enable_mask);
v = __raw_readl(dd->control_reg) & dd->enable_mask;
v >>= __ffs(dd->enable_mask);
if (v != OMAP3XXX_EN_DPLL_LOCKED)
rate = clk->parent->rate;
else
rate = clk->parent->rate * 2;
return rate;
}
