From: Daniel Baluta <daniel.baluta@nxp.com> To: <broonie@kernel.org>, <tiwai@suse.com>, <ckeepax@opensource.wolfsonmicro.com>, <arnd@arndb.de>, <lgirdwood@gmail.com> Cc: <patches@opensource.wolfsonmicro.com>, <alsa-devel@alsa-project.org>, <linux-kernel@vger.kernel.org>, Daniel Baluta <daniel.baluta@nxp.com> Subject: [PATCH 2/2] ASoC: codec: wm8960: Relax bit clock computation when using PLL Date: Fri, 21 Apr 2017 16:07:35 +0300 [thread overview] Message-ID: <1492780055-4892-3-git-send-email-daniel.baluta@nxp.com> (raw) In-Reply-To: <1492780055-4892-1-git-send-email-daniel.baluta@nxp.com> Bitclk is derived from sysclk using bclk_divs. Sysclk can be derived in two ways: (1) directly from MLCK (2) MCLK via PLL Commit 3c01b9ee2ab9d0d ("ASoC: codec: wm8960: Relax bit clock computation") relaxed bitclk computation when sysclk is directly derived from MCLK. Lets do the same thing when sysclk is derived via PLL. Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com> --- Here, I forced the following harmless initialization: *sysclk_idx = *dac_idx = *bclk_idx = -1; otherwise I would trigger a gcc false positive warning: sound/soc/codecs/wm8960.c: In function 'wm8960_configure_clocking': sound/soc/codecs/wm8960.c:810:46: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized] snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 6, j << 6); ~~^~~~ sound/soc/codecs/wm8960.c:806:44: warning: 'i' may be used uninitialized in this function [-Wmaybe-uninitialized] snd_soc_update_bits(codec, WM8960_CLOCK1, 3 << 1, i << 1); ~~^~~~ sound/soc/codecs/wm8960.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c index 8c87153..60700d5 100644 --- a/sound/soc/codecs/wm8960.c +++ b/sound/soc/codecs/wm8960.c @@ -679,6 +679,10 @@ int wm8960_configure_sysclk(struct wm8960_priv *wm8960, int mclk, * - freq_out = sysclk * sysclk_divs * - 10 * sysclk = bclk * bclk_divs * + * If we cannot find an exact match for (sysclk, lrclk, bclk) + * triplet, we relax the bclk such that bclk is chosen as the + * closest available frequency greater than expected bclk. + * * @codec: codec structure * @freq_in: input frequency used to derive freq out via PLL * @sysclk_idx: sysclk_divs index for found sysclk @@ -696,13 +700,15 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in, { struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec); int sysclk, bclk, lrclk, freq_out; - int diff, best_freq_out; + int diff, closest, best_freq_out; int i, j, k; bclk = wm8960->bclk; lrclk = wm8960->lrclk; + closest = freq_in; best_freq_out = -EINVAL; + *sysclk_idx = *dac_idx = *bclk_idx = -1; for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) { if (sysclk_divs[i] == -1) @@ -723,6 +729,13 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in, best_freq_out = freq_out; break; } + if (diff > 0 && closest > diff) { + *sysclk_idx = i; + *dac_idx = j; + *bclk_idx = k; + closest = diff; + best_freq_out = freq_out; + } } if (k != ARRAY_SIZE(bclk_divs)) break; -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: Daniel Baluta <daniel.baluta@nxp.com> To: broonie@kernel.org, tiwai@suse.com, ckeepax@opensource.wolfsonmicro.com, arnd@arndb.de, lgirdwood@gmail.com Cc: patches@opensource.wolfsonmicro.com, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, Daniel Baluta <daniel.baluta@nxp.com> Subject: [PATCH 2/2] ASoC: codec: wm8960: Relax bit clock computation when using PLL Date: Fri, 21 Apr 2017 16:07:35 +0300 [thread overview] Message-ID: <1492780055-4892-3-git-send-email-daniel.baluta@nxp.com> (raw) In-Reply-To: <1492780055-4892-1-git-send-email-daniel.baluta@nxp.com> Bitclk is derived from sysclk using bclk_divs. Sysclk can be derived in two ways: (1) directly from MLCK (2) MCLK via PLL Commit 3c01b9ee2ab9d0d ("ASoC: codec: wm8960: Relax bit clock computation") relaxed bitclk computation when sysclk is directly derived from MCLK. Lets do the same thing when sysclk is derived via PLL. Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com> --- Here, I forced the following harmless initialization: *sysclk_idx = *dac_idx = *bclk_idx = -1; otherwise I would trigger a gcc false positive warning: sound/soc/codecs/wm8960.c: In function 'wm8960_configure_clocking': sound/soc/codecs/wm8960.c:810:46: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized] snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 6, j << 6); ~~^~~~ sound/soc/codecs/wm8960.c:806:44: warning: 'i' may be used uninitialized in this function [-Wmaybe-uninitialized] snd_soc_update_bits(codec, WM8960_CLOCK1, 3 << 1, i << 1); ~~^~~~ sound/soc/codecs/wm8960.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c index 8c87153..60700d5 100644 --- a/sound/soc/codecs/wm8960.c +++ b/sound/soc/codecs/wm8960.c @@ -679,6 +679,10 @@ int wm8960_configure_sysclk(struct wm8960_priv *wm8960, int mclk, * - freq_out = sysclk * sysclk_divs * - 10 * sysclk = bclk * bclk_divs * + * If we cannot find an exact match for (sysclk, lrclk, bclk) + * triplet, we relax the bclk such that bclk is chosen as the + * closest available frequency greater than expected bclk. + * * @codec: codec structure * @freq_in: input frequency used to derive freq out via PLL * @sysclk_idx: sysclk_divs index for found sysclk @@ -696,13 +700,15 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in, { struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec); int sysclk, bclk, lrclk, freq_out; - int diff, best_freq_out; + int diff, closest, best_freq_out; int i, j, k; bclk = wm8960->bclk; lrclk = wm8960->lrclk; + closest = freq_in; best_freq_out = -EINVAL; + *sysclk_idx = *dac_idx = *bclk_idx = -1; for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) { if (sysclk_divs[i] == -1) @@ -723,6 +729,13 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in, best_freq_out = freq_out; break; } + if (diff > 0 && closest > diff) { + *sysclk_idx = i; + *dac_idx = j; + *bclk_idx = k; + closest = diff; + best_freq_out = freq_out; + } } if (k != ARRAY_SIZE(bclk_divs)) break; -- 2.7.4
next prev parent reply other threads:[~2017-04-21 13:07 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-04-21 13:07 [PATCH 0/2] Relax bitclk computation when using PLL Daniel Baluta 2017-04-21 13:07 ` Daniel Baluta 2017-04-21 13:07 ` [PATCH 1/2] ASoC: codec: wm9860: avoid maybe-uninitialized warning Daniel Baluta 2017-04-21 13:07 ` Daniel Baluta 2017-04-21 14:46 ` Arnd Bergmann 2017-04-21 14:46 ` Arnd Bergmann 2017-04-24 13:15 ` [alsa-devel] " Daniel Baluta 2017-04-24 13:15 ` Daniel Baluta 2017-04-24 15:27 ` [alsa-devel] " Arnd Bergmann 2017-04-24 15:27 ` Arnd Bergmann 2017-04-25 10:17 ` [alsa-devel] " Daniel Baluta 2017-04-25 10:17 ` Daniel Baluta 2017-04-21 13:07 ` Daniel Baluta [this message] 2017-04-21 13:07 ` [PATCH 2/2] ASoC: codec: wm8960: Relax bit clock computation when using PLL Daniel Baluta 2017-04-21 14:44 ` Arnd Bergmann 2017-04-21 14:44 ` Arnd Bergmann -- strict thread matches above, loose matches on Subject: below -- 2017-04-06 11:51 [PATCH 0/2] " Daniel Baluta 2017-04-06 11:51 ` [PATCH 2/2] " Daniel Baluta 2017-04-06 11:51 ` Daniel Baluta 2017-04-04 16:45 [PATCH 0/2] " Daniel Baluta 2017-04-04 16:45 ` [PATCH 2/2] " Daniel Baluta 2017-04-04 16:45 ` Daniel Baluta 2017-04-05 9:02 ` Charles Keepax 2017-04-05 9:02 ` Charles Keepax 2017-04-05 10:17 ` kbuild test robot 2017-04-05 10:17 ` kbuild test robot
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