/*
* OMAP3/4 - specific DPLL control functions
*
* Copyright (C) 2009-2010 Texas Instruments, Inc.
* Copyright (C) 2009-2010 Nokia Corporation
*
* Written by Paul Walmsley
* Testing and integration fixes by Jouni Högander
*
* 36xx support added by Vishwanath BS, Richard Woodruff, and Nishanth
* Menon
*
* 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/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/bitops.h>
#include <linux/clkdev.h>
#include <linux/clk/ti.h>
#include "clock.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
#define OMAP3XXX_EN_DPLL_LOCKED 0x7
/* Forward declarations */
static u32 omap3_dpll_autoidle_read(struct clk_hw_omap *clk);
static void omap3_dpll_deny_idle(struct clk_hw_omap *clk);
static void omap3_dpll_allow_idle(struct clk_hw_omap *clk);
/* Private functions */
/* _omap3_dpll_write_clken - write clken_bits arg to a DPLL's enable bits */
static void _omap3_dpll_write_clken(struct clk_hw_omap *clk, u8 clken_bits)
{
const struct dpll_data *dd;
u32 v;
dd = clk->dpll_data;
v = ti_clk_ll_ops->clk_readl(&dd->control_reg);
v &= ~dd->enable_mask;
v |= clken_bits << __ffs(dd->enable_mask);
ti_clk_ll_ops->clk_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_hw_omap *clk, u8 state)
{
const struct dpll_data *dd;
int i = 0;
int ret = -EINVAL;
const char *clk_name;
dd = clk->dpll_data;
clk_name = clk_hw_get_name(&clk->hw);
state <<= __ffs(dd->idlest_mask);
while (((ti_clk_ll_ops->clk_readl(&dd->idlest_reg) & dd->idlest_mask)
!= state) && i < MAX_DPLL_WAIT_TRIES) {
i++;
udelay(1);
}
if (i == MAX_DPLL_WAIT_TRIES) {
pr_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_hw_omap *clk, u8 n)
{
unsigned long fint;
u16 f = 0;
fint = clk_hw_get_rate(clk->dpll_data->clk_ref) / 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_hw_omap *clk)
{
const struct dpll_data *dd;
u8 ai;
u8 state = 1;
int r = 0;
pr_debug("clock: locking DPLL %s\n", clk_hw_get_name(&clk->hw));
dd = clk->dpll_data;
state <<= __ffs(dd->idlest_mask);
/* Check if already locked */
if ((ti_clk_ll_ops->clk_readl(&dd->idlest_reg) & dd->idlest_mask) ==
state)
goto done;
ai = omap3_dpll_autoidle_read(clk);
if (ai)
omap3_dpll_deny_idle(clk);
_omap3_dpll_write_clken(clk, DPLL_LOCKED);
r = _omap3_wait_dpll_status(<