Re: [alsa-devel] [PATCH v4] ASoC: AMD: Enable/Disable auxiliary clock via common clock framework

Hi Akshu

On Mon, Mar 26, 2018 at 3:12 AM Akshu Agrawal akshu.agrawal@amd.com wrote:

This enables/disables and sets auxiliary clock at 25Mhz. It uses common clock framework for proper ref counting. This approach will save power in comparison to keeping it always On in firmware.

V2: Correcting the pin to OSCOUT1 from OSCOUT2 V3: Fix error/warnings from kbuild test V4: Fix build errors for platform which do not support CONFIG_COMMON_CLK

TEST= aplay -vv <file> check register to see clock enabled kill aplay check register to see clock disabled

Signed-off-by: Akshu Agrawal akshu.agrawal@amd.com Acked-by: Alex Deucher alexander.deucher@amd.com

---

sound/soc/amd/acp-da7219-max98357a.c | 144

++++++++++++++++++++++++++++++++++-

1 file changed, 142 insertions(+), 2 deletions(-)

diff --git a/sound/soc/amd/acp-da7219-max98357a.c

b/sound/soc/amd/acp-da7219-max98357a.c

index 99c6b5c..3c77803 100644 --- a/sound/soc/amd/acp-da7219-max98357a.c +++ b/sound/soc/amd/acp-da7219-max98357a.c @@ -30,10 +30,13 @@ #include <sound/soc-dapm.h> #include <sound/jack.h> #include <linux/clk.h> +#include <linux/clkdev.h> +#include <linux/clk-provider.h> #include <linux/gpio.h> #include <linux/module.h> #include <linux/i2c.h> #include <linux/acpi.h> +#include <linux/types.h>

#include "../codecs/da7219.h" #include "../codecs/da7219-aad.h" @@ -41,6 +44,20 @@ #define CZ_PLAT_CLK 24000000 #define MCLK_RATE 24576000 #define DUAL_CHANNEL 2 +#define CLKDRVSTR2 0x28 +#define MISCCLKCNTL1 0x40 +#define OSCCLKENB 2 +#define OSCOUT1CLK25MHZ 16

These defines do not belong with the clocks above them, so please separate them. It might be helpful to add a comment describing what these addresses are, ie that they are registers of the SoC.

+struct cz_clock {

•   const char* acp_clks_name;
  

Why store this in the struct?

+#ifdef CONFIG_COMMON_CLK

•   struct clk_hw acp_clks_hw;
  

+#endif

•   struct clk_lookup *acp_clks_lookup;
  

Why store this in the struct?

•   struct clk *acp_clks;
  

Why store this in the struct?

•   void __iomem *res_base;
  

+};

static struct snd_soc_jack cz_jack; struct clk *da7219_dai_clk; @@ -91,6 +108,8 @@ static int cz_da7219_hw_params(struct

snd_pcm_substream *substream,

{ int ret = 0; struct snd_soc_pcm_runtime *rtd = substream->private_data;

•   struct snd_soc_card *card = rtd->card;
  

•   struct clk *acpd7219_clk;
  

     ret = clk_prepare_enable(da7219_dai_clk);
     if (ret < 0) {

@@ -98,13 +117,27 @@ static int cz_da7219_hw_params(struct

snd_pcm_substream *substream,

             return ret;
     }

•   acpd7219_clk = clk_get(card->dev, "acpd7219-clks");
  

•   ret = clk_prepare_enable(acpd7219_clk);
  

•   if (ret < 0) {
  

•           dev_err(rtd->dev, "can't enable oscillator clock %d\n",
  

ret);

•           return ret;
  

•   }
  

•    return ret;
  

  }

static int cz_da7219_hw_free(struct snd_pcm_substream *substream) {

•   struct snd_soc_pcm_runtime *rtd = substream->private_data;
  

•   struct snd_soc_card *card = rtd->card;
  

•   struct clk *acpd7219_clk;
  

•    clk_disable_unprepare(da7219_dai_clk);
  

•   acpd7219_clk = clk_get(card->dev, "acpd7219-clks");
  

•   clk_disable_unprepare(acpd7219_clk);
  

•    return 0;
  

  }

@@ -237,9 +270,113 @@ static int cz_fe_startup(struct snd_pcm_substream

*substream)

     .num_controls = ARRAY_SIZE(cz_mc_controls),

};

+#ifdef CONFIG_COMMON_CLK +static int acpd7219_clks_prepare(struct clk_hw *hw)

Should setting OSCCLKENB be the clock enable rather than prepare?

+{

•   u32 reg_val;
  

•   struct cz_clock *cz_clock_obj =
  

•           container_of(hw, struct cz_clock, acp_clks_hw);
  

nit: just "cz_clock" should be enough for all of these.

•   void __iomem *base = cz_clock_obj->res_base;
  

•   reg_val = readl(base + MISCCLKCNTL1);
  

•   reg_val &= ~(0x1 << OSCCLKENB);
  

•   writel(reg_val, base + MISCCLKCNTL1);
  

•   reg_val = readl(base + CLKDRVSTR2);
  

•   reg_val |= (0x1 << OSCOUT1CLK25MHZ);
  

•   writel(reg_val, base + CLKDRVSTR2);
  

Writing OSCOUT1CLK25MHZ sets the clock to 25 MHz (ie, instead of 48 MHz). So, technically this part should probably be in a set_rate() rather than prepare() [and reject other frequencies]?

•   return 0;
  

+}

+static void acpd7219_clks_unprepare(struct clk_hw *hw)

Similarly, can this be disable()?

+{

•   u32 reg_val;
  

•   struct cz_clock *cz_clock_obj =
  

•           container_of(hw, struct cz_clock, acp_clks_hw);
  

•   void __iomem *base = cz_clock_obj->res_base;
  

•   reg_val = readl(base + MISCCLKCNTL1);
  

•   reg_val |= (0x1 << OSCCLKENB);
  

•   writel(reg_val, base + MISCCLKCNTL1);
  

+}

+static int acpd7219_clks_is_enabled(struct clk_hw *hw) +{

•   u32 reg_val;
  

•   struct cz_clock *cz_clock_obj =
  

•           container_of(hw, struct cz_clock, acp_clks_hw);
  

•   void __iomem *base = cz_clock_obj->res_base;
  

•   reg_val = readl(base + MISCCLKCNTL1);
  

•   return !(reg_val & OSCCLKENB);
  

+}

+const struct clk_ops acpd7219_clks_ops = {

static const ...

•   .prepare = acpd7219_clks_prepare,
  

•   .unprepare = acpd7219_clks_unprepare,
  

•   .is_enabled = acpd7219_clks_is_enabled,
  

+};

+static int register_acpd7219_clocks(struct platform_device *pdev)

Can this be: __init

+{

•   struct clk_init_data init = {};
  

•   struct clk *acp_clks;
  

•   struct clk_lookup *acp_clks_lookup;
  

•   struct cz_clock *cz_clock_obj;
  

•   struct resource *res;
  

•   struct device dev = pdev->dev;
  

•   cz_clock_obj = kzalloc(sizeof(struct cz_clock), GFP_KERNEL);
  

•   if (!cz_clock_obj)
  

•           return -ENOMEM;
  

•   cz_clock_obj->acp_clks_name = "acpd7219-clks";
  

•   init.parent_names = NULL;
  

•   init.num_parents = 0;
  

•   init.name = cz_clock_obj->acp_clks_name;
  

•   init.ops = &acpd7219_clks_ops;
  

I think you can just do this all during: "struct clk_init_data init = { }". In fact, can't this done like this instead:

static const struct clk_init_data __initconst = { .name = "acpd7219-clks"; .ops = &acpd7219_clks_ops; };

•   cz_clock_obj->acp_clks_hw.init = &init;
  

•   acp_clks = devm_clk_register(&dev, &cz_clock_obj->acp_clks_hw);
  

•   if (IS_ERR(acp_clks))
  

•   {
  

•           dev_err(&dev, "Failed to register DAI clocks: %ld\n",
  

•                    PTR_ERR(acp_clks));
  

•           return -EINVAL;
  

propagate PTR_ERR(acp_clks), instead?

•   }
  

•   cz_clock_obj->acp_clks = acp_clks;
  

•   acp_clks_lookup = clkdev_create(acp_clks,
  

cz_clock_obj->acp_clks_name,

•                                   "%s", dev_name(&dev));
  

•   if (!acp_clks_lookup)
  

•           dev_warn(&dev, "Failed to create DAI clkdev");
  

•   else
  

•           cz_clock_obj->acp_clks_lookup =
  

acp_clks_lookup;clkdev_create

•   res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  

•   if (!res) {
  

•           dev_err(&pdev->dev, "Failed to get misc io resource.\n");
  

•           return -EINVAL;
  

•   }
  

•   cz_clock_obj->res_base = devm_ioremap_nocache(&pdev->dev,
  

res->start,

•                                   resource_size(res));
  

•   if (!cz_clock_obj->res_base)
  

•           return -ENOMEM;
  

•   return 0;
  

+} +#else +static int register_acpd7219_clocks(struct platform_device *pdev) +{

•   return 0;
  

+} +#endif /* CONFIG_COMMON_CLK */

• static int cz_probe(struct platform_device *pdev) {

•   int ret;
  

•   int ret = 0;
  

Do not initialize this before it is used.

     struct snd_soc_card *card;

     card = &cz_card;

@@ -252,7 +389,10 @@ static int cz_probe(struct platform_device *pdev) cz_card.name, ret); return ret; }

•   return 0;
  

•   ret = register_acpd7219_clocks(pdev);
  

•   return ret;
  

Just: return register_acpd7219_clocks(pdev);

Thanks, -Dan

}

static const struct acpi_device_id cz_audio_acpi_match[] = {

1.9.1