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"); 153