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-rw-r--r--sound/soc/codecs/adau-utils.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/sound/soc/codecs/adau-utils.c b/sound/soc/codecs/adau-utils.c
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+++ b/sound/soc/codecs/adau-utils.c
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+/*
+ * Shared helper functions for devices from the ADAU family
+ *
+ * Copyright 2011-2016 Analog Devices Inc.
+ * Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/gcd.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "adau-utils.h"
+
+int adau_calc_pll_cfg(unsigned int freq_in, unsigned int freq_out,
+ uint8_t regs[5])
+{
+ unsigned int r, n, m, i, j;
+ unsigned int div;
+
+ if (!freq_out) {
+ r = 0;
+ n = 0;
+ m = 0;
+ div = 0;
+ } else {
+ if (freq_out % freq_in != 0) {
+ div = DIV_ROUND_UP(freq_in, 13500000);
+ freq_in /= div;
+ r = freq_out / freq_in;
+ i = freq_out % freq_in;
+ j = gcd(i, freq_in);
+ n = i / j;
+ m = freq_in / j;
+ div--;
+ } else {
+ r = freq_out / freq_in;
+ n = 0;
+ m = 0;
+ div = 0;
+ }
+ if (n > 0xffff || m > 0xffff || div > 3 || r > 8 || r < 2)
+ return -EINVAL;
+ }
+
+ regs[0] = m >> 8;
+ regs[1] = m & 0xff;
+ regs[2] = n >> 8;
+ regs[3] = n & 0xff;
+ regs[4] = (r << 3) | (div << 1);
+ if (m != 0)
+ regs[4] |= 1; /* Fractional mode */
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(adau_calc_pll_cfg);
+
+MODULE_DESCRIPTION("ASoC ADAU audio CODECs shared helper functions");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_LICENSE("GPL v2");