blob: 0f927c538613e63b7461b5b972caac927de98255 [file] [log] [blame]
/*
* Copyright (c) 2013, The Linux Foundation. All rights reserved.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/bug.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/clk-provider.h>
#include <linux/regmap.h>
#include <asm/div64.h>
#include "clk-pll.h"
#define PLL_OUTCTRL BIT(0)
#define PLL_BYPASSNL BIT(1)
#define PLL_RESET_N BIT(2)
#define PLL_LOCK_COUNT_SHIFT 8
#define PLL_LOCK_COUNT_MASK 0x3f
#define PLL_BIAS_COUNT_SHIFT 14
#define PLL_BIAS_COUNT_MASK 0x3f
#define PLL_VOTE_FSM_ENA BIT(20)
#define PLL_VOTE_FSM_RESET BIT(21)
static int clk_pll_enable(struct clk_hw *hw)
{
struct clk_pll *pll = to_clk_pll(hw);
int ret;
u32 mask, val;
mask = PLL_OUTCTRL | PLL_RESET_N | PLL_BYPASSNL;
ret = regmap_read(pll->clkr.regmap, pll->mode_reg, &val);
if (ret)
return ret;
/* Skip if already enabled or in FSM mode */
if ((val & mask) == mask || val & PLL_VOTE_FSM_ENA)
return 0;
/* Disable PLL bypass mode. */
ret = regmap_update_bits(pll->clkr.regmap, pll->mode_reg, PLL_BYPASSNL,
PLL_BYPASSNL);
if (ret)
return ret;
/*
* H/W requires a 5us delay between disabling the bypass and
* de-asserting the reset. Delay 10us just to be safe.
*/
udelay(10);
/* De-assert active-low PLL reset. */
ret = regmap_update_bits(pll->clkr.regmap, pll->mode_reg, PLL_RESET_N,
PLL_RESET_N);
if (ret)
return ret;
/* Wait until PLL is locked. */
udelay(50);
/* Enable PLL output. */
ret = regmap_update_bits(pll->clkr.regmap, pll->mode_reg, PLL_OUTCTRL,
PLL_OUTCTRL);
if (ret)
return ret;
return 0;
}
static void clk_pll_disable(struct clk_hw *hw)
{
struct clk_pll *pll = to_clk_pll(hw);
u32 mask;
u32 val;
regmap_read(pll->clkr.regmap, pll->mode_reg, &val);
/* Skip if in FSM mode */
if (val & PLL_VOTE_FSM_ENA)
return;
mask = PLL_OUTCTRL | PLL_RESET_N | PLL_BYPASSNL;
regmap_update_bits(pll->clkr.regmap, pll->mode_reg, mask, 0);
}
static unsigned long
clk_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
{
struct clk_pll *pll = to_clk_pll(hw);
u32 l, m, n;
unsigned long rate;
u64 tmp;
regmap_read(pll->clkr.regmap, pll->l_reg, &l);
regmap_read(pll->clkr.regmap, pll->m_reg, &m);
regmap_read(pll->clkr.regmap, pll->n_reg, &n);
l &= 0x3ff;
m &= 0x7ffff;
n &= 0x7ffff;
rate = parent_rate * l;
if (n) {
tmp = parent_rate;
tmp *= m;
do_div(tmp, n);
rate += tmp;
}
return rate;
}
const struct clk_ops clk_pll_ops = {
.enable = clk_pll_enable,
.disable = clk_pll_disable,
.recalc_rate = clk_pll_recalc_rate,
};
EXPORT_SYMBOL_GPL(clk_pll_ops);
static int wait_for_pll(struct clk_pll *pll)
{
u32 val;
int count;
int ret;
const char *name = __clk_get_name(pll->clkr.hw.clk);
/* Wait for pll to enable. */
for (count = 200; count > 0; count--) {
ret = regmap_read(pll->clkr.regmap, pll->status_reg, &val);
if (ret)
return ret;
if (val & BIT(pll->status_bit))
return 0;
udelay(1);
}
WARN(1, "%s didn't enable after voting for it!\n", name);
return -ETIMEDOUT;
}
static int clk_pll_vote_enable(struct clk_hw *hw)
{
int ret;
struct clk_pll *p = to_clk_pll(__clk_get_hw(__clk_get_parent(hw->clk)));
ret = clk_enable_regmap(hw);
if (ret)
return ret;
return wait_for_pll(p);
}
const struct clk_ops clk_pll_vote_ops = {
.enable = clk_pll_vote_enable,
.disable = clk_disable_regmap,
};
EXPORT_SYMBOL_GPL(clk_pll_vote_ops);
static void
clk_pll_set_fsm_mode(struct clk_pll *pll, struct regmap *regmap)
{
u32 val;
u32 mask;
/* De-assert reset to FSM */
regmap_update_bits(regmap, pll->mode_reg, PLL_VOTE_FSM_RESET, 0);
/* Program bias count and lock count */
val = 1 << PLL_BIAS_COUNT_SHIFT;
mask = PLL_BIAS_COUNT_MASK << PLL_BIAS_COUNT_SHIFT;
mask |= PLL_LOCK_COUNT_MASK << PLL_LOCK_COUNT_SHIFT;
regmap_update_bits(regmap, pll->mode_reg, mask, val);
/* Enable PLL FSM voting */
regmap_update_bits(regmap, pll->mode_reg, PLL_VOTE_FSM_ENA,
PLL_VOTE_FSM_ENA);
}
static void clk_pll_configure(struct clk_pll *pll, struct regmap *regmap,
const struct pll_config *config)
{
u32 val;
u32 mask;
regmap_write(regmap, pll->l_reg, config->l);
regmap_write(regmap, pll->m_reg, config->m);
regmap_write(regmap, pll->n_reg, config->n);
val = config->vco_val;
val |= config->pre_div_val;
val |= config->post_div_val;
val |= config->mn_ena_mask;
val |= config->main_output_mask;
val |= config->aux_output_mask;
mask = config->vco_mask;
mask |= config->pre_div_mask;
mask |= config->post_div_mask;
mask |= config->mn_ena_mask;
mask |= config->main_output_mask;
mask |= config->aux_output_mask;
regmap_update_bits(regmap, pll->config_reg, mask, val);
}
void clk_pll_configure_sr_hpm_lp(struct clk_pll *pll, struct regmap *regmap,
const struct pll_config *config, bool fsm_mode)
{
clk_pll_configure(pll, regmap, config);
if (fsm_mode)
clk_pll_set_fsm_mode(pll, regmap);
}
EXPORT_SYMBOL_GPL(clk_pll_configure_sr_hpm_lp);