[alsa-devel] [PATCH v4] ASoC: AMD: Enable/Disable auxiliary clock via common clock framework
Daniel Kurtz
djkurtz at chromium.org
Tue Mar 27 06:22:40 CEST 2018
Hi Akshu
On Mon, Mar 26, 2018 at 3:12 AM Akshu Agrawal <akshu.agrawal at 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 at amd.com>
> Acked-by: Alex Deucher <alexander.deucher at 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
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