On Tue, Dec 12, 2017 at 07:58:56PM +0800, Chen.Liu wrote:
From: "Chen.Liu" chen.liu.opensource@gmail.com
Please make sure to CC patches@opensource.cirrus.com on patches to the Wolfson CODEC drivers.
Issue: MCLK=24MHZ,SYSCLOCK=12.288MHZ. When the 'wm8960_set_dai_pll' function is called,the driver will
wm8960_set_pll, not wm8960_set_dai_pll?
prompted "WM8960 PLL: unsupported N = 4" error message. However,the value of PLLN should be 8 based on the table45( PLL Frequency Examples) of the wm8960 chip manuanl.
Reason: The intergrated PLL can be used to generate SYSCLK for the wm8960. The pll_factors function in the wm8974.c file is mainly responsible
Assuming that should be wm8960.c?
-static int pll_factors(unsigned int source, unsigned int target, +static int pll_factors(struct snd_soc_codec *codec,
unsigned int source, unsigned int target, struct _pll_div *pll_div){ unsigned long long Kpart; unsigned int K, Ndiv, Nmod;
int unsupport = 0;
u16 reg;
pr_debug("WM8960 PLL: setting %dHz->%dHz\n", source, target);
/* Scale up target to PLL operating frequency */ target *= 4;
+retry:
- if (unsupport) {
target *= 2;unsupport += 1;- } Ndiv = target / source; if (Ndiv < 6) { source >>= 1;
@@ -1056,8 +1064,12 @@ static int pll_factors(unsigned int source, unsigned int target, pll_div->pre_div = 0;
Feels like it would be nice to wrap this Ndiv calculation in a loop rather than adding the goto into the below if statement.
if ((Ndiv < 6) || (Ndiv > 12)) {
pr_err("WM8960 PLL: Unsupported N=%d\n", Ndiv);return -EINVAL;
if (unsupport == 2) {pr_err("WM8960 PLL: Unsupported N=%d\n", Ndiv);return -EINVAL;}unsupport = 1;goto retry;}
pll_div->n = Ndiv;
@@ -1077,6 +1089,11 @@ static int pll_factors(unsigned int source, unsigned int target,
pll_div->k = K;
- if (unsupport) {
reg = snd_soc_read(codec, WM8960_CLOCK1) | WM8960_SYSCLK_DIV_2;snd_soc_write(codec, WM8960_CLOCK1, reg);
snd_soc_update_bits?
Also there is no code that seems to reset this bit should we later ask for a configuration that no longer needs it.
Thanks, Charles