From 2f8aab3d29fda158fa49ecae94b3b3a4b494909d Mon Sep 17 00:00:00 2001 From: Bard Liao Date: Mon, 27 Nov 2017 20:03:14 +0800 Subject: ASoC: rl6231: get better PLL parameters For those which can only get approximation PLL out cases, this patch will use higher resolution to get a better PLL parameter. Signed-off-by: Bard Liao Signed-off-by: Mark Brown --- sound/soc/codecs/rl6231.c | 95 ++++++++++++++++++++++++++++++++--------------- 1 file changed, 66 insertions(+), 29 deletions(-) diff --git a/sound/soc/codecs/rl6231.c b/sound/soc/codecs/rl6231.c index 974a904..33690e9 100644 --- a/sound/soc/codecs/rl6231.c +++ b/sound/soc/codecs/rl6231.c @@ -13,6 +13,7 @@ #include #include +#include #include "rl6231.h" /** @@ -106,6 +107,25 @@ static const struct pll_calc_map pll_preset_table[] = { {19200000, 24576000, 3, 30, 3, 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. @@ -120,9 +140,11 @@ 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, red, n_t, pll_out, in_t, out_t; - int n = 0, m = 0, m_t = 0; - int red_t = abs(freq_out - freq_in); + 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 bypass = false; if (RL6231_PLL_INP_MAX < freq_in || RL6231_PLL_INP_MIN > freq_in) @@ -140,39 +162,54 @@ int rl6231_pll_calc(const unsigned int freq_in, } } - k = 100000000 / freq_out - 2; - if (k > RL6231_PLL_K_MAX) - k = RL6231_PLL_K_MAX; - for (n_t = 0; n_t <= max_n; n_t++) { - in_t = freq_in / (k + 2); - pll_out = freq_out / (n_t + 2); - if (in_t < 0) - continue; - if (in_t == pll_out) { - bypass = true; - n = n_t; - goto code_find; - } - red = abs(in_t - pll_out); - if (red < red_t) { - bypass = true; - n = n_t; - m = m_t; - if (red == 0) + 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; + 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 < 0) + continue; + if (in_t == pll_out) { + bypass = true; + n = n_t; + k = k_t; goto code_find; - red_t = red; - } - for (m_t = 0; m_t <= max_m; m_t++) { - out_t = in_t / (m_t + 2); - red = abs(out_t - pll_out); + } + out_t = in_t / (k_t + 2); + red = abs(f_out - out_t); if (red < red_t) { - bypass = false; + bypass = true; n = n_t; - m = m_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) { + 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"); -- cgit v1.1 From 790dde243f7dd5b8e576686eba0b891470b09f57 Mon Sep 17 00:00:00 2001 From: Bard Liao Date: Thu, 21 Dec 2017 11:21:33 +0800 Subject: ASoC: rl6231: remove never matched if condition (in_t < 0) will never be true since in_t is unsigned. Signed-off-by: Bard Liao Signed-off-by: Mark Brown --- sound/soc/codecs/rl6231.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/sound/soc/codecs/rl6231.c b/sound/soc/codecs/rl6231.c index 33690e9..7ef3b54 100644 --- a/sound/soc/codecs/rl6231.c +++ b/sound/soc/codecs/rl6231.c @@ -178,8 +178,6 @@ int rl6231_pll_calc(const unsigned int freq_in, 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 < 0) - continue; if (in_t == pll_out) { bypass = true; n = n_t; -- cgit v1.1