Re: [alsa-devel] Why open-coding in sof_hda_bus_init()?

On 5/31/19 12:11 PM, Takashi Iwai wrote:

Hi,

while looking at SOF code due to the recent debugging session, I noticed that sof_hda_bus_init() is basically an open-code of the existing snd_hdac_ext_bus_init(). Why don't we simply call snd_hdac_ext_bus_init() like below?

It's intentional. We've been asked since Day1 of SOF on ApolloLake to provide a 'self-contained' controller-only support that has no dependency on the snd_hdac library for solutions where HDaudio links+codecs are not used (typically IOT devices). This was driven by the lack of separation between layers in that library as well as a desire to have a dual-license. That's why you see the init and some of the basic utilities re-implemented for SOF.

However for cases where HDaudio+HDMI are required, we didn't want to reinvent the wheel - HDaudio is complicated enough - and do make use of this snd_hdac library.

We have a config SND_SOC_SOF_HDA that controls in which mode we operate, and it enables HDMI by default (for I2S+HDMI solutions). To get external HDaudio codecs you need the additional SOF_HDAUDIO_CODEC kconfig.

Does this help?

The only thing that differs is the handling of bus->id number, where SOF fixes to zero (which was actually done in a patch after the first commit). But judging from the comment, this doesn't seem like a big matter, as we assume a single bus, so far...

thanks,

Takashi

---

diff --git a/sound/soc/sof/intel/Makefile b/sound/soc/sof/intel/Makefile index b8f58e006e29..f42450a9a7b6 100644 --- a/sound/soc/sof/intel/Makefile +++ b/sound/soc/sof/intel/Makefile @@ -7,7 +7,7 @@ snd-sof-intel-ipc-objs := intel-ipc.o

snd-sof-intel-hda-common-objs := hda.o hda-loader.o hda-stream.o hda-trace.o \ hda-dsp.o hda-ipc.o hda-ctrl.o hda-pcm.o \

• 		 hda-dai.o hda-bus.o \
  

• 		 hda-dai.o \
  	 apl.o cnl.o
  
  

  snd-sof-intel-hda-objs := hda-codec.o

diff --git a/sound/soc/sof/intel/hda-bus.c b/sound/soc/sof/intel/hda-bus.c deleted file mode 100644 index a7e6d8227df6..000000000000 --- a/sound/soc/sof/intel/hda-bus.c +++ /dev/null @@ -1,111 +0,0 @@ -// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) -// -// This file is provided under a dual BSD/GPLv2 license. When using or -// redistributing this file, you may do so under either license. -// -// Copyright(c) 2018 Intel Corporation. All rights reserved. -// -// Authors: Keyon Jie yang.jie@linux.intel.com

-#include <linux/io.h> -#include <sound/hdaudio.h> -#include "../sof-priv.h" -#include "hda.h"

-#if IS_ENABLED(CONFIG_SND_SOC_SOF_HDA)

-static const struct hdac_bus_ops bus_ops = {

• .command = snd_hdac_bus_send_cmd,
• .get_response = snd_hdac_bus_get_response,

-};

-#endif

-static void sof_hda_writel(u32 value, u32 __iomem *addr) -{

• writel(value, addr);

-}

-static u32 sof_hda_readl(u32 __iomem *addr) -{

• return readl(addr);

-}

-static void sof_hda_writew(u16 value, u16 __iomem *addr) -{

• writew(value, addr);

-}

-static u16 sof_hda_readw(u16 __iomem *addr) -{

• return readw(addr);

-}

-static void sof_hda_writeb(u8 value, u8 __iomem *addr) -{

• writeb(value, addr);

-}

-static u8 sof_hda_readb(u8 __iomem *addr) -{

• return readb(addr);

-}

-static int sof_hda_dma_alloc_pages(struct hdac_bus *bus, int type,

• 		   size_t size, struct snd_dma_buffer *buf)
  

-{

• return snd_dma_alloc_pages(type, bus->dev, size, buf);

-}

-static void sof_hda_dma_free_pages(struct hdac_bus *bus,

• 		   struct snd_dma_buffer *buf)
  

-{

• snd_dma_free_pages(buf);

-}

-static const struct hdac_io_ops io_ops = {

• .reg_writel = sof_hda_writel,
• .reg_readl = sof_hda_readl,
• .reg_writew = sof_hda_writew,
• .reg_readw = sof_hda_readw,
• .reg_writeb = sof_hda_writeb,
• .reg_readb = sof_hda_readb,
• .dma_alloc_pages = sof_hda_dma_alloc_pages,
• .dma_free_pages = sof_hda_dma_free_pages,

-};

-/*

• • This can be used for both with/without hda link support.
• */

-void sof_hda_bus_init(struct hdac_bus *bus, struct device *dev,

•       const struct hdac_ext_bus_ops *ext_ops)
  

-{

• memset(bus, 0, sizeof(*bus));
• bus->dev = dev;
• bus->io_ops = &io_ops;
• INIT_LIST_HEAD(&bus->stream_list);
• bus->irq = -1;
• bus->ext_ops = ext_ops;
• /*

• * There is only one HDA bus atm. keep the index as 0.
  

• * Need to fix when there are more than one HDA bus.
  

• */
  

• bus->idx = 0;
• spin_lock_init(&bus->reg_lock);

-#if IS_ENABLED(CONFIG_SND_SOC_SOF_HDA)

• INIT_LIST_HEAD(&bus->codec_list);
• INIT_LIST_HEAD(&bus->hlink_list);
• mutex_init(&bus->cmd_mutex);
• mutex_init(&bus->lock);
• bus->ops = &bus_ops;
• INIT_WORK(&bus->unsol_work, snd_hdac_bus_process_unsol_events);
• bus->cmd_dma_state = true;

-#endif

-} diff --git a/sound/soc/sof/intel/hda.h b/sound/soc/sof/intel/hda.h index 92d45c43b4b1..a9de6a297b56 100644 --- a/sound/soc/sof/intel/hda.h +++ b/sound/soc/sof/intel/hda.h @@ -532,8 +532,11 @@ int hda_dsp_ctrl_init_chip(struct snd_sof_dev *sdev, bool full_reset); /*

• HDA bus operations.

*/ -void sof_hda_bus_init(struct hdac_bus *bus, struct device *dev,

•       const struct hdac_ext_bus_ops *ext_ops);
  

+static inline void sof_hda_bus_init(struct hdac_bus *bus, struct device *dev,

• 		    const struct hdac_ext_bus_ops *ext_ops)
  

+{

• snd_hdac_ext_bus_init(bus, dev, NULL, NULL, ext_ops);

+}

#if IS_ENABLED(CONFIG_SND_SOC_SOF_HDA) /*