On Sun, May 1, 2016 at 11:49 AM, Fabio Estevam festevam@gmail.com wrote:

On Sat, Apr 30, 2016 at 8:18 AM, Petr Kulhavy brain@jikos.cz wrote:

...

Hi,

I'm trying to run the latest mainline kernel 4.6 on the iMX6UL EVK. The board mostly works and the only problem is audio. Even though the sound card is detected and the ALSA mixer can be controlled there is no MCLK coming out of the SAI2 interface.

Also, have you tried setting bit 20 (SAI2_MCLK_DIR) of register IOMUXC_GPR_GPR1?

You can set this bit in the bootloader for a quick test.

So I tried it myself and here are the changes I did:

diff --git a/arch/arm/boot/dts/imx6ul-14x14-evk.dts b/arch/arm/boot/dts/imx6ul-14x14-evk.dts index 7207280..8c20783 100644 --- a/arch/arm/boot/dts/imx6ul-14x14-evk.dts +++ b/arch/arm/boot/dts/imx6ul-14x14-evk.dts @@ -36,6 +36,23 @@ enable-active-high; }; }; + + sound { + compatible = "simple-audio-card"; + simple-audio-card,name = "mx6ul-evk-sound-card"; + simple-audio-card,format = "i2s"; + simple-audio-card,bitclock-master = <&dailink_master>; + simple-audio-card,frame-master = <&dailink_master>; + + simple-audio-card,cpu { + sound-dai = <&sai2>; + }; + + dailink_master: simple-audio-card,codec { + sound-dai = <&codec>; + clocks = <&clks IMX6UL_CLK_SAI2>; + }; + }; };

&cpu0 { @@ -43,6 +60,20 @@ soc-supply = <&reg_soc>; };

+&i2c2 { + clock_frequency = <100000>; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_i2c2>; + status = "okay"; + + codec: wm8960@1a { + #sound-dai-cells = <0>; + compatible = "wlf,wm8960"; + reg = <0x1a>; + wlf,shared-lrclk; + }; +}; + &fec1 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_enet1>; @@ -86,6 +117,18 @@ }; };

+&sai2 { + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_sai2>; + + assigned-clocks = <&clks IMX6UL_CLK_SAI2_SEL>, + <&clks IMX6UL_CLK_SAI2>; + assigned-clock-parents = <&clks IMX6UL_CLK_PLL4_AUDIO_DIV>; + assigned-clock-rates = <0>, <12288000>; + + status = "okay"; +}; + &snvs_poweroff { status = "okay"; }; @@ -272,6 +315,17 @@ >; };

+ pinctrl_sai2: sai2grp { + fsl,pins = < + MX6UL_PAD_JTAG_TDI__SAI2_TX_BCLK 0x17088 + MX6UL_PAD_JTAG_TDO__SAI2_TX_SYNC 0x17088 + MX6UL_PAD_JTAG_TRST_B__SAI2_TX_DATA 0x11088 + MX6UL_PAD_JTAG_TCK__SAI2_RX_DATA 0x11088 + MX6UL_PAD_JTAG_TMS__SAI2_MCLK 0x17088 + MX6UL_PAD_SNVS_TAMPER4__GPIO5_IO04 0x17059 + >; + }; + pinctrl_pwm1: pwm1grp { fsl,pins = < MX6UL_PAD_GPIO1_IO08__PWM1_OUT 0x110b0

Hi Fabio,

On 02/05/16 15:17, Fabio Estevam wrote:

Hi Petr,

I can get audio with mainline now, but it plays with an incorrect pitch.

Here is a quick hack to allow MCLK to be driven:

--- a/arch/arm/mach-imx/mach-imx6ul.c +++ b/arch/arm/mach-imx/mach-imx6ul.c @@ -22,9 +22,12 @@ static void __init imx6ul_enet_clk_init(void) struct regmap *gpr;

     gpr = syscon_regmap_lookup_by_compatible("fsl,imx6ul-iomuxc-gpr");

•   if (!IS_ERR(gpr))
  

•   if (!IS_ERR(gpr)) {
             regmap_update_bits(gpr, IOMUXC_GPR1, IMX6UL_GPR1_ENET_CLK_DIR,
                                IMX6UL_GPR1_ENET_CLK_OUTPUT);
  

•           regmap_update_bits(gpr, IOMUXC_GPR1, (1 << 20), (1 << 20));
  

•   }
     else
             pr_err("failed to find fsl,imx6ul-iomux-gpr regmap\n");
  

Cool, now my board plays too! Thanks!

As next steps we need:

1. Fix the sound pitch

Mine plays at the correct speed. For the correct speed the clock assignment from the Freescale DTS needs to be copied, so that the SAI2 clock generates 12.288MHz. Below are the relevant nodes from my DTS:

&clks { assigned-clocks = <&clks IMX6UL_CLK_PLL4_AUDIO_DIV>; assigned-clock-rates = <786432000>; };

&sai2 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_sai2>;

assigned-clocks = <&clks IMX6UL_CLK_SAI2_SEL>, <&clks IMX6UL_CLK_SAI2>; assigned-clock-parents = <&clks IMX6UL_CLK_PLL4_AUDIO_DIV>; assigned-clock-rates = <0>, <12288000>;

status = "okay"; };

2. Find a proper way to enable MCLK.

I would tend to put the control of the SAIx_MCLK_DIR into the SAI driver and if needed add an extra boolean property like "enable-mclk-output". Leaving it independent makes not much sense, for binding to the clock/pinmux it's too generic and the Freescale solution with a gpr phandle isn't very lucky either as it forces the use of the fsl soundcard and doesn't allow e.g. the simple-audio-card.

But let's see what else the Freescale or ALSA developers suggest.

Cheers Petr