mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-31 08:28:13 +00:00
ac1125daf0
Existing implementation checks all divider values and tracks 'red' proximity value for the frequency. But as divider array is monotonically increasing the first divider that gives DMIC rate in 3MHz range is the best one we should use. No need for 'red' zone tracking. Additionally make sure that DMIC frequency is higher 1MHz. Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com> Acked-by: Oder Chiou <oder_chiou@realtek.com> Signed-off-by: Mark Brown <broonie@kernel.org>
205 lines
4.3 KiB
C
205 lines
4.3 KiB
C
/*
|
|
* rl6231.c - RL6231 class device shared support
|
|
*
|
|
* Copyright 2014 Realtek Semiconductor Corp.
|
|
*
|
|
* Author: Oder Chiou <oder_chiou@realtek.com>
|
|
*
|
|
* 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/regmap.h>
|
|
|
|
#include "rl6231.h"
|
|
|
|
/**
|
|
* rl6231_get_pre_div - Return the value of pre divider.
|
|
*
|
|
* @map: map for setting.
|
|
* @reg: register.
|
|
* @sft: shift.
|
|
*
|
|
* Return the value of pre divider from given register value.
|
|
* Return negative error code for unexpected register value.
|
|
*/
|
|
int rl6231_get_pre_div(struct regmap *map, unsigned int reg, int sft)
|
|
{
|
|
int pd, val;
|
|
|
|
regmap_read(map, reg, &val);
|
|
|
|
val = (val >> sft) & 0x7;
|
|
|
|
switch (val) {
|
|
case 0:
|
|
case 1:
|
|
case 2:
|
|
case 3:
|
|
pd = val + 1;
|
|
break;
|
|
case 4:
|
|
pd = 6;
|
|
break;
|
|
case 5:
|
|
pd = 8;
|
|
break;
|
|
case 6:
|
|
pd = 12;
|
|
break;
|
|
case 7:
|
|
pd = 16;
|
|
break;
|
|
default:
|
|
pd = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
return pd;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rl6231_get_pre_div);
|
|
|
|
/**
|
|
* rl6231_calc_dmic_clk - Calculate the frequency divider parameter of dmic.
|
|
*
|
|
* @rate: base clock rate.
|
|
*
|
|
* Choose divider parameter that gives the highest possible DMIC frequency in
|
|
* 1MHz - 3MHz range.
|
|
*/
|
|
int rl6231_calc_dmic_clk(int rate)
|
|
{
|
|
int div[] = {2, 3, 4, 6, 8, 12};
|
|
int i;
|
|
|
|
if (rate < 1000000 * div[0]) {
|
|
pr_warn("Base clock rate %d is too low\n", rate);
|
|
return -EINVAL;
|
|
}
|
|
|
|
for (i = 0; i < ARRAY_SIZE(div); i++) {
|
|
/* find divider that gives DMIC frequency below 3MHz */
|
|
if (3000000 * div[i] >= rate)
|
|
return i;
|
|
}
|
|
|
|
pr_warn("Base clock rate %d is too high\n", rate);
|
|
return -EINVAL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rl6231_calc_dmic_clk);
|
|
|
|
struct pll_calc_map {
|
|
unsigned int pll_in;
|
|
unsigned int pll_out;
|
|
int k;
|
|
int n;
|
|
int m;
|
|
bool m_bp;
|
|
};
|
|
|
|
static const struct pll_calc_map pll_preset_table[] = {
|
|
{19200000, 24576000, 3, 30, 3, false},
|
|
};
|
|
|
|
/**
|
|
* rl6231_pll_calc - Calcualte PLL M/N/K code.
|
|
* @freq_in: external clock provided to codec.
|
|
* @freq_out: target clock which codec works on.
|
|
* @pll_code: Pointer to structure with M, N, K and bypass flag.
|
|
*
|
|
* Calcualte M/N/K code to configure PLL for codec.
|
|
*
|
|
* Returns 0 for success or negative error code.
|
|
*/
|
|
int rl6231_pll_calc(const unsigned int freq_in,
|
|
const unsigned int freq_out, struct rl6231_pll_code *pll_code)
|
|
{
|
|
int max_n = RL6231_PLL_N_MAX, max_m = RL6231_PLL_M_MAX;
|
|
int i, k, red, n_t, pll_out, in_t, out_t;
|
|
int n = 0, m = 0, m_t = 0;
|
|
int red_t = abs(freq_out - freq_in);
|
|
bool bypass = false;
|
|
|
|
if (RL6231_PLL_INP_MAX < freq_in || RL6231_PLL_INP_MIN > freq_in)
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(pll_preset_table); i++) {
|
|
if (freq_in == pll_preset_table[i].pll_in &&
|
|
freq_out == pll_preset_table[i].pll_out) {
|
|
k = pll_preset_table[i].k;
|
|
m = pll_preset_table[i].m;
|
|
n = pll_preset_table[i].n;
|
|
bypass = pll_preset_table[i].m_bp;
|
|
pr_debug("Use preset PLL parameter table\n");
|
|
goto code_find;
|
|
}
|
|
}
|
|
|
|
k = 100000000 / freq_out - 2;
|
|
if (k > RL6231_PLL_K_MAX)
|
|
k = RL6231_PLL_K_MAX;
|
|
for (n_t = 0; n_t <= max_n; n_t++) {
|
|
in_t = freq_in / (k + 2);
|
|
pll_out = freq_out / (n_t + 2);
|
|
if (in_t < 0)
|
|
continue;
|
|
if (in_t == pll_out) {
|
|
bypass = true;
|
|
n = n_t;
|
|
goto code_find;
|
|
}
|
|
red = abs(in_t - pll_out);
|
|
if (red < red_t) {
|
|
bypass = true;
|
|
n = n_t;
|
|
m = m_t;
|
|
if (red == 0)
|
|
goto code_find;
|
|
red_t = red;
|
|
}
|
|
for (m_t = 0; m_t <= max_m; m_t++) {
|
|
out_t = in_t / (m_t + 2);
|
|
red = abs(out_t - pll_out);
|
|
if (red < red_t) {
|
|
bypass = false;
|
|
n = n_t;
|
|
m = m_t;
|
|
if (red == 0)
|
|
goto code_find;
|
|
red_t = red;
|
|
}
|
|
}
|
|
}
|
|
pr_debug("Only get approximation about PLL\n");
|
|
|
|
code_find:
|
|
|
|
pll_code->m_bp = bypass;
|
|
pll_code->m_code = m;
|
|
pll_code->n_code = n;
|
|
pll_code->k_code = k;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rl6231_pll_calc);
|
|
|
|
int rl6231_get_clk_info(int sclk, int rate)
|
|
{
|
|
int i, pd[] = {1, 2, 3, 4, 6, 8, 12, 16};
|
|
|
|
if (sclk <= 0 || rate <= 0)
|
|
return -EINVAL;
|
|
|
|
rate = rate << 8;
|
|
for (i = 0; i < ARRAY_SIZE(pd); i++)
|
|
if (sclk == rate * pd[i])
|
|
return i;
|
|
|
|
return -EINVAL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rl6231_get_clk_info);
|
|
|
|
MODULE_DESCRIPTION("RL6231 class device shared support");
|
|
MODULE_AUTHOR("Oder Chiou <oder_chiou@realtek.com>");
|
|
MODULE_LICENSE("GPL v2");
|