sound/soc/codecs/rl6231.c

   1 /*
   2  * rl6231.c - RL6231 class device shared support
   3  *
   4  * Copyright 2014 Realtek Semiconductor Corp.
   5  *
   6  * Author: Oder Chiou <oder_chiou@realtek.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/moduleparam.h>
  15 #include <linux/init.h>
  16 #include <linux/delay.h>
  17 #include <linux/pm.h>
  18 #include <linux/gpio.h>
  19 #include <linux/i2c.h>
  20 #include <linux/regmap.h>
  21 #include <linux/of.h>
  22 #include <linux/of_gpio.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/spi/spi.h>
  25 #include <linux/acpi.h>
  26 #include <sound/core.h>
  27 #include <sound/pcm.h>
  28 #include <sound/pcm_params.h>
  29 #include <sound/soc.h>
  30 #include <sound/soc-dapm.h>
  31 #include <sound/initval.h>
  32 #include <sound/tlv.h>
  33
  34 #include "rl6231.h"
  35
  36 /**
  37  * rl6231_calc_dmic_clk - Calculate the parameter of dmic.
  38  *
  39  * @rate: base clock rate.
  40  *
  41  * Choose dmic clock between 1MHz and 3MHz.
  42  * It is better for clock to approximate 3MHz.
  43  */
  44 int rl6231_calc_dmic_clk(int rate)
  45 {
  46         int div[] = {2, 3, 4, 6, 8, 12}, idx = -EINVAL;
  47         int i, red, bound, temp;
  48
  49         red = 3000000 * 12;
  50         for (i = 0; i < ARRAY_SIZE(div); i++) {
  51                 bound = div[i] * 3000000;
  52                 if (rate > bound)
  53                         continue;
  54                 temp = bound - rate;
  55                 if (temp < red) {
  56                         red = temp;
  57                         idx = i;
  58                 }
  59         }
  60
  61         return idx;
  62 }
  63 EXPORT_SYMBOL_GPL(rl6231_calc_dmic_clk);
  64
  65 /**
  66  * rl6231_pll_calc - Calcualte PLL M/N/K code.
  67  * @freq_in: external clock provided to codec.
  68  * @freq_out: target clock which codec works on.
  69  * @pll_code: Pointer to structure with M, N, K and bypass flag.
  70  *
  71  * Calcualte M/N/K code to configure PLL for codec.
  72  *
  73  * Returns 0 for success or negative error code.
  74  */
  75 int rl6231_pll_calc(const unsigned int freq_in,
  76         const unsigned int freq_out, struct rl6231_pll_code *pll_code)
  77 {
  78         int max_n = RL6231_PLL_N_MAX, max_m = RL6231_PLL_M_MAX;
  79         int k, red, n_t, pll_out, in_t, out_t;
  80         int n = 0, m = 0, m_t = 0;
  81         int red_t = abs(freq_out - freq_in);
  82         bool bypass = false;
  83
  84         if (RL6231_PLL_INP_MAX < freq_in || RL6231_PLL_INP_MIN > freq_in)
  85                 return -EINVAL;
  86
  87         k = 100000000 / freq_out - 2;
  88         if (k > RL6231_PLL_K_MAX)
  89                 k = RL6231_PLL_K_MAX;
  90         for (n_t = 0; n_t <= max_n; n_t++) {
  91                 in_t = freq_in / (k + 2);
  92                 pll_out = freq_out / (n_t + 2);
  93                 if (in_t < 0)
  94                         continue;
  95                 if (in_t == pll_out) {
  96                         bypass = true;
  97                         n = n_t;
  98                         goto code_find;
  99                 }
 100                 red = abs(in_t - pll_out);
 101                 if (red < red_t) {
 102                         bypass = true;
 103                         n = n_t;
 104                         m = m_t;
 105                         if (red == 0)
 106                                 goto code_find;
 107                         red_t = red;
 108                 }
 109                 for (m_t = 0; m_t <= max_m; m_t++) {
 110                         out_t = in_t / (m_t + 2);
 111                         red = abs(out_t - pll_out);
 112                         if (red < red_t) {
 113                                 bypass = false;
 114                                 n = n_t;
 115                                 m = m_t;
 116                                 if (red == 0)
 117                                         goto code_find;
 118                                 red_t = red;
 119                         }
 120                 }
 121         }
 122         pr_debug("Only get approximation about PLL\n");
 123
 124 code_find:
 125
 126         pll_code->m_bp = bypass;
 127         pll_code->m_code = m;
 128         pll_code->n_code = n;
 129         pll_code->k_code = k;
 130         return 0;
 131 }
 132 EXPORT_SYMBOL_GPL(rl6231_pll_calc);
 133
 134 int rl6231_get_clk_info(int sclk, int rate)
 135 {
 136         int i, pd[] = {1, 2, 3, 4, 6, 8, 12, 16};
 137
 138         if (sclk <= 0 || rate <= 0)
 139                 return -EINVAL;
 140
 141         rate = rate << 8;
 142         for (i = 0; i < ARRAY_SIZE(pd); i++)
 143                 if (sclk == rate * pd[i])
 144                         return i;
 145
 146         return -EINVAL;
 147 }
 148 EXPORT_SYMBOL_GPL(rl6231_get_clk_info);
 149
 150 MODULE_DESCRIPTION("RL6231 class device shared support");
 151 MODULE_AUTHOR("Oder Chiou <oder_chiou@realtek.com>");
 152 MODULE_LICENSE("GPL v2");