Re: [PATCH 02/13] ASoC: amd: add Pink Sardine ACP PCI driver

["Amadeusz Sławiński" <amadeuszx.slawinski@linux.intel.com>]

On 8/12/2022 2:07 PM, Syed Saba kareem wrote:
> ACP is a PCI audio device.
> This patch adds PCI driver to bind to this device and get
> PCI resources for Pink Sardine Platform.
> 
> Signed-off-by: Syed Saba Kareem <Syed.SabaKareem@amd.com>
> Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
> ---
>   sound/soc/amd/ps/acp62.h  | 21 +++++++++
>   sound/soc/amd/ps/pci-ps.c | 94 +++++++++++++++++++++++++++++++++++++++
>   2 files changed, 115 insertions(+)
>   create mode 100644 sound/soc/amd/ps/acp62.h
>   create mode 100644 sound/soc/amd/ps/pci-ps.c
> 
> diff --git a/sound/soc/amd/ps/acp62.h b/sound/soc/amd/ps/acp62.h
> new file mode 100644
> index 000000000000..e91762240c93
> --- /dev/null
> +++ b/sound/soc/amd/ps/acp62.h
> @@ -0,0 +1,21 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * AMD ALSA SoC PDM Driver
> + *
> + * Copyright (C) 2022 Advanced Micro Devices, Inc. All rights reserved.
> + */
> +
> +#include <sound/acp62_chip_offset_byte.h>
> +
> +#define ACP_DEVICE_ID 0x15E2
> +#define ACP62_PHY_BASE_ADDRESS 0x1240000
> +
> +static inline u32 acp62_readl(void __iomem *base_addr)
> +{
> +	return readl(base_addr - ACP62_PHY_BASE_ADDRESS);

Can't you just define offsets in header, without ACP62_PHY_BASE_ADDRESS? 
Then you won't need to subtract the value here?
I mean like:
#define ACP_DMA_CNTL_0                                0x0000
#define ACP_DMA_CNTL_1                                0x0004
...
instead of
#define ACP_DMA_CNTL_0                                0x1240000
#define ACP_DMA_CNTL_1                                0x1240004
...
Seems a bit weird to me, to just define values with offset if it is not 
needed...

> +}
> +
> +static inline void acp62_writel(u32 val, void __iomem *base_addr)
> +{
> +	writel(val, base_addr - ACP62_PHY_BASE_ADDRESS);
> +}

Same here

> diff --git a/sound/soc/amd/ps/pci-ps.c b/sound/soc/amd/ps/pci-ps.c
> new file mode 100644
> index 000000000000..25169797275c
> --- /dev/null
> +++ b/sound/soc/amd/ps/pci-ps.c
> @@ -0,0 +1,94 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * AMD Pink Sardine ACP PCI Driver
> + *
> + * Copyright 2022 Advanced Micro Devices, Inc.
> + */
> +
> +#include <linux/pci.h>
> +#include <linux/module.h>
> +#include <linux/io.h>
> +
> +#include "acp62.h"
> +
> +struct acp62_dev_data {
> +	void __iomem *acp62_base;
> +};
> +
> +static int snd_acp62_probe(struct pci_dev *pci,
> +			   const struct pci_device_id *pci_id)
> +{
> +	struct acp62_dev_data *adata;
> +	u32 addr;
> +	int ret;
> +
> +	/* Pink Sardine device check */
> +	switch (pci->revision) {
> +	case 0x63:
> +		break;
> +	default:
> +		dev_dbg(&pci->dev, "acp62 pci device not found\n");
> +		return -ENODEV;
> +	}
> +	if (pci_enable_device(pci)) {
> +		dev_err(&pci->dev, "pci_enable_device failed\n");
> +		return -ENODEV;
> +	}
> +
> +	ret = pci_request_regions(pci, "AMD ACP6.2 audio");
> +	if (ret < 0) {
> +		dev_err(&pci->dev, "pci_request_regions failed\n");
> +		goto disable_pci;
> +	}
> +		adata = devm_kzalloc(&pci->dev, sizeof(struct acp62_dev_data),
> +				     GFP_KERNEL);

Wrong indentation in assignment above?

> +	if (!adata) {
> +		ret = -ENOMEM;
> +		goto release_regions;
> +	}
> +
> +	addr = pci_resource_start(pci, 0);
> +	adata->acp62_base = devm_ioremap(&pci->dev, addr,
> +					 pci_resource_len(pci, 0));
> +	if (!adata->acp62_base) {
> +		ret = -ENOMEM;
> +		goto release_regions;
> +	}
> +	pci_set_master(pci);
> +	pci_set_drvdata(pci, adata);
> +	return 0;
> +release_regions:
> +	pci_release_regions(pci);
> +disable_pci:
> +	pci_disable_device(pci);
> +
> +	return ret;
> +}
> +
> +static void snd_acp62_remove(struct pci_dev *pci)
> +{
> +	pci_release_regions(pci);
> +	pci_disable_device(pci);
> +}
> +
> +static const struct pci_device_id snd_acp62_ids[] = {
> +	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, ACP_DEVICE_ID),

This one is optional, but you could also use:
PCI_VDEVICE(AMD, ACP_DEVICE_ID)
which is bit shorter and at least to me seems a bit more readable.

> +	.class = PCI_CLASS_MULTIMEDIA_OTHER << 8,
> +	.class_mask = 0xffffff },
> +	{ 0, },
> +};
> +MODULE_DEVICE_TABLE(pci, snd_acp62_ids);
> +
> +static struct pci_driver ps_acp62_driver  = {
> +	.name = KBUILD_MODNAME,
> +	.id_table = snd_acp62_ids,
> +	.probe = snd_acp62_probe,
> +	.remove = snd_acp62_remove,
> +};
> +
> +module_pci_driver(ps_acp62_driver);
> +
> +MODULE_AUTHOR("Vijendar.Mukunda@amd.com");
> +MODULE_AUTHOR("Syed.SabaKareem@amd.com");
> +MODULE_DESCRIPTION("AMD ACP Pink Sardine PCI driver");
> +MODULE_LICENSE("GPL v2");