/*
* OMAP3-specific clock framework functions
*
* Copyright (C) 2007-2008 Texas Instruments, Inc.
* Copyright (C) 2007-2008 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.
*/
#undef DEBUG
#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 <mach/clock.h>
#include <mach/sram.h>
#include <asm/div64.h>
#include <asm/bitops.h>
#include "memory.h"
#include "clock.h"
#include "clock34xx.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
/**
* omap3_dpll_recalc - recalculate DPLL rate
* @clk: DPLL struct clk
*
* Recalculate and propagate the DPLL rate.
*/
static void omap3_dpll_recalc(struct clk *clk)
{
clk->rate = omap2_get_dpll_rate(clk);
propagate_rate(clk);
}
/* _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;
dd = clk->dpll_data;
cm_rmw_reg_bits(dd->enable_mask, clken_bits << __ffs(dd->enable_mask),
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;
u32 idlest_mask;
dd = clk->dpll_data;
state <<= dd->idlest_bit;
idlest_mask = 1 << dd->idlest_bit;
while (((cm_read_reg(dd->idlest_reg) & 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;
}
/* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */
/*
* _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;
if (clk == &dpll3_ck)
return -EINVAL;
pr_debug("clock: locking DPLL %s\n", clk->name);
ai = omap3_dpll_autoidle_read(clk);
_omap3_dpll_write_clken(clk, DPLL_LOCKED);
if (ai) {
/*
* If no downstream clocks are enabled, CM_IDLEST bit
* may never become active, so don't wait for DPLL to lock.
*/
r = 0;
omap3_dpll_allow_idle(clk);
} else {
r = _omap3_wait_dpll_status(clk, 1);
omap3_dpll_deny_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 == &dpll3_ck)
return -EINVAL;
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 == &dpll3_ck)
return -EINVAL;
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_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.
*/
static int omap3_noncore_dpll_enable(struct clk *clk)
{
int r;
if (clk == &dpll3_ck)
return -EINVAL;
if (clk->parent->rate == clk_get_rate(clk))
r = _omap3_noncore_dpll_bypass(clk);
else
r = _omap3_noncore_dpll_lock(clk);
return r;
}
/**
* 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.
*/
static void omap3_noncore_dpll_disable(struct clk *clk)
{
if (clk == &dpll3_ck)
return;
_omap3_noncore_dpll_stop(clk);
}
/**
* 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.
*/
static 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 = cm_read_reg(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.
*/
static void omap3_dpll_allow_idle(struct clk *clk)
{
const struct dpll_data *dd;
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.
*/
cm_rmw_reg_bits(dd->autoidle_mask,
DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask),
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.
*/
static void omap3_dpll_deny_idle(struct clk *clk)
{
const struct dpll_data *dd;
if (!clk || !clk->dpll_data)
return;
dd = clk->dpll_data;
cm_rmw_reg_bits(dd->autoidle_mask,
DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask),
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.
*/
static void omap3_clkoutx2_recalc(struct clk *clk)
{
const struct dpll_data *dd;
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->control_reg || !dd->enable_mask);
v = __raw_readl(dd->control_reg) & dd->enable_mask;
v >>= __ffs(dd->enable_mask);
if (v != DPLL_LOCKED)
clk->rate = clk->parent->rate;
else
clk->rate = clk->parent->rate * 2;
if (clk->flags & RATE_PROPAGATES)
propagate_rate(clk);
}
/* Common clock code */
/*
* As it is structured now, this will prevent an OMAP2/3 multiboot
* kernel from compiling. This will need further attention.
*/
#if defined(CONFIG_ARCH_OMAP3)
static struct clk_functions omap2_clk_functions = {
.clk_enable = omap2_clk_enable,
.clk_disable = omap2_clk_disable,
.clk_round_rate = omap2_clk_round_rate,
.clk_set_rate = omap2_clk_set_rate,
.clk_set_parent = omap2_clk_set_parent,
.clk_disable_unused = omap2_clk_disable_unused,
};
/*
* Set clocks for bypass mode for reboot to work.
*/
void omap2_clk_prepare_for_reboot(void)
{
/* REVISIT: Not ready for 343x */
#if 0
u32 rate;
if (vclk == NULL || sclk == NULL)
return;
rate = clk_get_rate(sclk);
clk_set_rate(vclk, rate);
#endif
}
/* REVISIT: Move this init stuff out into clock.c */
/*
* Switch the MPU rate if specified on cmdline.
* We cannot do this early until cmdline is parsed.
*/
static int __init omap2_clk_arch_init(void)
{
if (!mpurate)
return -EINVAL;
/* REVISIT: not yet ready for 343x */
#if 0
if (omap2_select_table_rate(&virt_prcm_set, mpurate))
printk(KERN_ERR "Could not find matching MPU rate\n");
#endif
recalculate_root_clocks();
printk(KERN_INFO "Switched to new clocking rate (Crystal/DPLL3/MPU): "
"%ld.%01ld/%ld/%ld MHz\n",
(osc_sys_ck.rate / 1000000), (osc_sys_ck.rate / 100000) % 10,
(core_ck.rate / 1000000), (dpll1_fck.rate / 1000000)) ;
return 0;
}
arch_initcall(omap2_clk_arch_init);
int __init omap2_clk_init(void)
{
/* struct prcm_config *prcm; */
struct clk **clkp;
/* u32 clkrate; */
u32 cpu_clkflg;
/* REVISIT: Ultimately this will be used for multiboot */
#if 0
if (cpu_is_omap242x()) {
cpu_mask = RATE_IN_242X;
cpu_clkflg = CLOCK_IN_OMAP242X;
clkp = onchip_24xx_clks;
} else if (cpu_is_omap2430()) {
cpu_mask = RATE_IN_243X;
cpu_clkflg = CLOCK_IN_OMAP243X;
clkp = onchip_24xx_clks;
}
#endif
if (cpu_is_omap34xx()) {
cpu_mask = RATE_IN_343X;
cpu_clkflg = CLOCK_IN_OMAP343X;
clkp = onchip_34xx_clks;
/*
* Update this if there are further clock changes between ES2
* and production parts
*/
if (is_sil_rev_equal_to(OMAP3430_REV_ES1_0)) {
/* No 3430ES1-only rates exist, so no RATE_IN_3430ES1 */
cpu_clkflg |= CLOCK_IN_OMAP3430ES1;
} else {
cpu_mask |= RATE_IN_3430ES2;
cpu_clkflg |= CLOCK_IN_OMAP3430ES2;
}
}
clk_init(&omap2_clk_functions);
for (clkp = onchip_34xx_clks;
clkp < onchip_34xx_clks + ARRAY_SIZE(onchip_34xx_clks);
clkp++) {
if ((*clkp)->flags & cpu_clkflg)
clk_register(*clkp);
}
/* REVISIT: Not yet ready for OMAP3 */
#if 0
/* Check the MPU rate set by bootloader */
clkrate = omap2_get_dpll_rate_24xx(&dpll_ck);
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 <= clkrate)
break;
}
curr_prcm_set = prcm;
#endif
recalculate_root_clocks();
printk(KERN_INFO "Clocking rate (Crystal/DPLL/ARM core): "
"%ld.%01ld/%ld/%ld MHz\n",
(osc_sys_ck.rate / 1000000), (osc_sys_ck.rate / 100000) % 10,
(core_ck.rate / 1000000), (arm_fck.rate / 1000000));
/*
* Only enable those clocks we will need, let the drivers
* enable other clocks as necessary
*/
clk_enable_init_clocks();
/* Avoid sleeping during omap2_clk_prepare_for_reboot() */
/* REVISIT: not yet ready for 343x */
#if 0
vclk = clk_get(NULL, "virt_prcm_set");
sclk = clk_get(NULL, "sys_ck");
#endif
return 0;
}
#endif
