1 files changed, 253 insertions, 0 deletions
diff --git a/sound/soc/codecs/rl6231.c b/sound/soc/codecs/rl6231.c
new file mode 100644
index 0000000000..d1fc170642
--- /dev/null
+++ b/sound/soc/codecs/rl6231.c
@@ -0,0 +1,253 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * rl6231.c - RL6231 class device shared support
+ *
+ * Copyright 2014 Realtek Semiconductor Corp.
+ *
+ * Author: Oder Chiou <oder_chiou@realtek.com>
+ */
+
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <linux/gcd.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)
+{
+	static const 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++) {
+		if ((div[i] % 3) == 0)
+			continue;
+		/* find divider that gives DMIC frequency below 1.536MHz */
+		if (1536000 * 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;
+	bool k_bp;
+};
+
+static const struct pll_calc_map pll_preset_table[] = {
+	{19200000,  4096000,  23, 14, 1, false, false},
+	{19200000,  24576000,  3, 30, 3, false, false},
+	{48000000,  3840000,  23,  2, 0, false, false},
+	{3840000,   24576000,  3, 30, 0, true, false},
+	{3840000,   22579200,  3,  5, 0, true, false},
+};
+
+static unsigned int find_best_div(unsigned int in,
+	unsigned int max, unsigned int div)
+{
+	unsigned int d;
+
+	if (in <= max)
+		return 1;
+
+	d = in / max;
+	if (in % max)
+		d++;
+
+	while (div % d != 0)
+		d++;
+
+
+	return d;
+}
+
+/**
+ * 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, m_bypass and k_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, n_t;
+	int k_t, min_k, max_k, n = 0, m = 0, m_t = 0;
+	unsigned int red, pll_out, in_t, out_t, div, div_t;
+	unsigned int red_t = abs(freq_out - freq_in);
+	unsigned int f_in, f_out, f_max;
+	bool m_bypass = false, k_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;
+			m_bypass = pll_preset_table[i].m_bp;
+			k_bypass = pll_preset_table[i].k_bp;
+			pr_debug("Use preset PLL parameter table\n");
+			goto code_find;
+		}
+	}
+
+	min_k = 80000000 / freq_out - 2;
+	max_k = 150000000 / freq_out - 2;
+	if (max_k > RL6231_PLL_K_MAX)
+		max_k = RL6231_PLL_K_MAX;
+	if (min_k > RL6231_PLL_K_MAX)
+		min_k = max_k = RL6231_PLL_K_MAX;
+	div_t = gcd(freq_in, freq_out);
+	f_max = 0xffffffff / RL6231_PLL_N_MAX;
+	div = find_best_div(freq_in, f_max, div_t);
+	f_in = freq_in / div;
+	f_out = freq_out / div;
+	k = min_k;
+	if (min_k < -1)
+		min_k = -1;
+	for (k_t = min_k; k_t <= max_k; k_t++) {
+		for (n_t = 0; n_t <= max_n; n_t++) {
+			in_t = f_in * (n_t + 2);
+			pll_out = f_out * (k_t + 2);
+			if (in_t == pll_out) {
+				m_bypass = true;
+				n = n_t;
+				k = k_t;
+				goto code_find;
+			}
+			out_t = in_t / (k_t + 2);
+			red = abs(f_out - out_t);
+			if (red < red_t) {
+				m_bypass = true;
+				n = n_t;
+				m = 0;
+				k = k_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) * (k_t + 2));
+				red = abs(f_out - out_t);
+				if (red < red_t) {
+					m_bypass = false;
+					n = n_t;
+					m = m_t;
+					k = k_t;
+					if (red == 0)
+						goto code_find;
+					red_t = red;
+				}
+			}
+		}
+	}
+	pr_debug("Only get approximation about PLL\n");
+
+code_find:
+	if (k == -1) {
+		k_bypass = true;
+		k = 0;
+	}
+
+	pll_code->m_bp = m_bypass;
+	pll_code->k_bp = k_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;
+	static const int 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");