2 * rl6231.c - RL6231 class device shared support
4 * Copyright 2014 Realtek Semiconductor Corp.
6 * Author: Oder Chiou <oder_chiou@realtek.com>
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.
13 #include <linux/module.h>
18 * rl6231_calc_dmic_clk - Calculate the parameter of dmic.
20 * @rate: base clock rate.
22 * Choose dmic clock between 1MHz and 3MHz.
23 * It is better for clock to approximate 3MHz.
25 int rl6231_calc_dmic_clk(int rate)
27 int div[] = {2, 3, 4, 6, 8, 12}, idx = -EINVAL;
28 int i, red, bound, temp;
31 for (i = 0; i < ARRAY_SIZE(div); i++) {
32 bound = div[i] * 3000000;
44 EXPORT_SYMBOL_GPL(rl6231_calc_dmic_clk);
55 static const struct pll_calc_map pll_preset_table[] = {
56 {19200000, 24576000, 3, 30, 3, false},
60 * rl6231_pll_calc - Calcualte PLL M/N/K code.
61 * @freq_in: external clock provided to codec.
62 * @freq_out: target clock which codec works on.
63 * @pll_code: Pointer to structure with M, N, K and bypass flag.
65 * Calcualte M/N/K code to configure PLL for codec.
67 * Returns 0 for success or negative error code.
69 int rl6231_pll_calc(const unsigned int freq_in,
70 const unsigned int freq_out, struct rl6231_pll_code *pll_code)
72 int max_n = RL6231_PLL_N_MAX, max_m = RL6231_PLL_M_MAX;
73 int i, k, red, n_t, pll_out, in_t, out_t;
74 int n = 0, m = 0, m_t = 0;
75 int red_t = abs(freq_out - freq_in);
78 if (RL6231_PLL_INP_MAX < freq_in || RL6231_PLL_INP_MIN > freq_in)
81 for (i = 0; i < ARRAY_SIZE(pll_preset_table); i++) {
82 if (freq_in == pll_preset_table[i].pll_in &&
83 freq_out == pll_preset_table[i].pll_out) {
84 k = pll_preset_table[i].k;
85 m = pll_preset_table[i].m;
86 n = pll_preset_table[i].n;
87 bypass = pll_preset_table[i].m_bp;
88 pr_debug("Use preset PLL parameter table\n");
93 k = 100000000 / freq_out - 2;
94 if (k > RL6231_PLL_K_MAX)
96 for (n_t = 0; n_t <= max_n; n_t++) {
97 in_t = freq_in / (k + 2);
98 pll_out = freq_out / (n_t + 2);
101 if (in_t == pll_out) {
106 red = abs(in_t - pll_out);
115 for (m_t = 0; m_t <= max_m; m_t++) {
116 out_t = in_t / (m_t + 2);
117 red = abs(out_t - pll_out);
128 pr_debug("Only get approximation about PLL\n");
132 pll_code->m_bp = bypass;
133 pll_code->m_code = m;
134 pll_code->n_code = n;
135 pll_code->k_code = k;
138 EXPORT_SYMBOL_GPL(rl6231_pll_calc);
140 int rl6231_get_clk_info(int sclk, int rate)
142 int i, pd[] = {1, 2, 3, 4, 6, 8, 12, 16};
144 if (sclk <= 0 || rate <= 0)
148 for (i = 0; i < ARRAY_SIZE(pd); i++)
149 if (sclk == rate * pd[i])
154 EXPORT_SYMBOL_GPL(rl6231_get_clk_info);
156 MODULE_DESCRIPTION("RL6231 class device shared support");
157 MODULE_AUTHOR("Oder Chiou <oder_chiou@realtek.com>");
158 MODULE_LICENSE("GPL v2");