Date:   Mon, 03 Feb 2020 06:52:37 -0800
From:   Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
To:     Sandeep Singh <Sandeep.Singh@....com>, jikos@...nel.org,
        benjamin.tissoires@...hat.com, linux-kernel@...r.kernel.org,
        linux-input@...r.kernel.org, jic23@...nel.org,
        linux-iio@...r.kernel.org
Cc:     Shyam-sundar.S-k@....com,
        Nehal Shah <Nehal-bakulchandra.Shah@....com>
Subject: Re: [PATCH v2 2/4] SFH: PCI driver to add support of AMD sensor
 fusion Hub using HID framework

On Wed, 2020-01-29 at 09:57 +0530, Sandeep Singh wrote:
> From: Sandeep Singh <sandeep.singh@....com>
> 
> AMD SFH uses HID over PCIe bus.SFH fw is part of MP2
> processor and it runs on MP2
First time explain MP2 means.

> where in driver resides
> on X86.This part of module will communicate with MP2 FW and
> provide that data into DRAM

Some minor comments below.

> 
> Signed-off-by: Sandeep Singh <sandeep.singh@....com>
> Signed-off-by: Nehal Shah <Nehal-bakulchandra.Shah@....com>
> Reported-by: kbuild test robot <lkp@...el.com>
> ---
>  drivers/hid/Kconfig                    |   2 +
>  drivers/hid/Makefile                   |   1 +
>  drivers/hid/amd-sfh-hid/Kconfig        |  17 +++
>  drivers/hid/amd-sfh-hid/Makefile       |  17 +++
>  drivers/hid/amd-sfh-hid/amd_mp2_pcie.c | 256
> +++++++++++++++++++++++++++++++++
>  drivers/hid/amd-sfh-hid/amd_mp2_pcie.h | 169 ++++++++++++++++++++++
>  6 files changed, 462 insertions(+)
>  create mode 100644 drivers/hid/amd-sfh-hid/Kconfig
>  create mode 100644 drivers/hid/amd-sfh-hid/Makefile
>  create mode 100644 drivers/hid/amd-sfh-hid/amd_mp2_pcie.c
>  create mode 100644 drivers/hid/amd-sfh-hid/amd_mp2_pcie.h
> 
> diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
> index 494a39e..b253ad1 100644
> --- a/drivers/hid/Kconfig
> +++ b/drivers/hid/Kconfig
> @@ -1155,4 +1155,6 @@ source "drivers/hid/i2c-hid/Kconfig"
>  
>  source "drivers/hid/intel-ish-hid/Kconfig"
>  
> +source "drivers/hid/amd-sfh-hid/Kconfig"
> +
>  endmenu
> diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
> index bfefa36..15a08e8 100644
> --- a/drivers/hid/Makefile
> +++ b/drivers/hid/Makefile
> @@ -139,3 +139,4 @@ obj-$(CONFIG_I2C_HID)		+= i2c-hid/
>  
>  obj-$(CONFIG_INTEL_ISH_HID)	+= intel-ish-hid/
>  obj-$(INTEL_ISH_FIRMWARE_DOWNLOADER)	+= intel-ish-hid/
> +obj-$(CONFIG_AMD_SFH_HID)       += amd-sfh-hid/
> diff --git a/drivers/hid/amd-sfh-hid/Kconfig b/drivers/hid/amd-sfh-
> hid/Kconfig
> new file mode 100644
> index 0000000..e2dee39
> --- /dev/null
> +++ b/drivers/hid/amd-sfh-hid/Kconfig
> @@ -0,0 +1,17 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +menu "AMD SFH HID support"
> +	depends on (X86_64 || COMPILE_TEST) && PCI
> +
> +config AMD_SFH_HID
> +	tristate "AMD Sensor Fusion Hub"
> +	default n
By default is "n" anyway, so don't need this line.

> +	select HID
> +	help
> +	  If you say yes to this option, support will be included for
> the AMD
> +	  Sensor Fusion Hub.

Better to explain, what user will get benefit. This way user will make
sure that they will include this option.

> +
> +	  This driver can also be built as modules. If so, the modules
> will
> +	  be  called amd-mp2-pcie and amd-sfhtp-hid.
What is mp2?

> +	  Say Y
or M

>  here if you want to support AMD SFH. If unsure, say N.
> +
> +endmenu
> diff --git a/drivers/hid/amd-sfh-hid/Makefile b/drivers/hid/amd-sfh-
> hid/Makefile
> new file mode 100644
> index 0000000..5aae934
> --- /dev/null
> +++ b/drivers/hid/amd-sfh-hid/Makefile
> @@ -0,0 +1,17 @@
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Makefile - AMD SFH HID drivers
> +# Copyright (c) 2019-2020, Advanced Micro Devices, Inc.
> +#
> +#
> +ccflags-m := -Werror
> +obj-$(CONFIG_AMD_SFH_HID) += amd-mp2-pcie.o
> +amd-mp2-pcie-objs := amd_mp2_pcie.o
> +
> +obj-$(CONFIG_AMD_SFH_HID) +=amd-sfhtp-hid.o
> +amd-sfhtp-hid-objs := amdsfh-hid.o
> +amd-sfhtp-hid-objs+= amdsfh-hid-client.o
> +amd-sfhtp-hid-objs+= amdsfh-debugfs.o
> +amd-sfhtp-hid-objs+= hid_descriptor/amd_sfh_hid_descriptor.o
> +
> +ccflags-y += -I$(srctree)/$(src)/
> diff --git a/drivers/hid/amd-sfh-hid/amd_mp2_pcie.c
> b/drivers/hid/amd-sfh-hid/amd_mp2_pcie.c
> new file mode 100644
> index 0000000..f264d60
> --- /dev/null
> +++ b/drivers/hid/amd-sfh-hid/amd_mp2_pcie.c
> @@ -0,0 +1,256 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * AMD MP2 PCIe communication driver
> + *
> + * Authors: Shyam Sundar S K <Shyam-sundar.S-k@....com>
> + *          Nehal Bakulchandra Shah <Nehal-bakulchandra.Shah@....com
> >
> + */
> +
> +#include "amd_mp2_pcie.h"
This should be at the end.
First standard include for <linux/*> then local includes

> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +
> +#define DRIVER_NAME	"pcie_mp2_amd"
> +#define DRIVER_DESC	"AMD(R) PCIe MP2 Communication Driver"
> +#define DRIVER_VER	"1.0"
Do you think you will keep updating this version number for changes?

> +
> +#define	ACEL_EN		BIT(ACCEL_IDX)
> +#define	GYRO_EN		BIT(GYRO_IDX)
> +#define MAGNO_EN	BIT(MAG_IDX)
> +#define ALS_EN		BIT(AMBIENT_LIGHT_IDX)
> +
> +int amd_start_sensor(struct pci_dev *pdev, struct
> amd_mp2_sensor_info info)
> +{
> +	struct amd_mp2_dev *privdata = pci_get_drvdata(pdev);
> +	union sfh_cmd_base cmd_base;
> +	union sfh_command_parameter cmd_param;
> +
Generally better to define local variable in the order, for example for
the above. Same for other functions.

	struct amd_mp2_dev *privdata = pci_get_drvdata(pdev);
	union sfh_command_parameter cmd_param;
	union sfh_cmd_base cmd_base;


> +	/*fill up command register*/
> +	cmd_base.ul = 0;
> +	cmd_base.s.cmd_id = enable_sensor;
> +	cmd_base.s.period = info.period;
> +	cmd_base.s.sensor_id = info.sensor_idx;
> +
> +	/*fill up command param register*/
> +	cmd_param.ul = 0;
> +	cmd_param.s.buffer_layout = 1;
> +	cmd_param.s.buffer_length = 16;
> +
> +	write64((u64)info.phy_address, privdata->mmio + AMD_C2P_MSG2);
> +	writel(cmd_param.ul, privdata->mmio + AMD_C2P_MSG1);
> +	writel(cmd_base.ul, privdata->mmio + AMD_C2P_MSG0);
> +	return 0;

Can this function be void(). There is no error return anywhere?
Same for the function below.

> +}
> +EXPORT_SYMBOL_GPL(amd_start_sensor);
> +
> +int amd_stop_sensor(struct pci_dev *pdev, u16 sensor_idx)
> +{
> +	struct amd_mp2_dev *privdata = pci_get_drvdata(pdev);
> +	union sfh_cmd_base cmd_base;
> +
> +	/* fill up command register */
> +	cmd_base.ul = 0;
> +	cmd_base.s.cmd_id = disable_sensor;
> +	cmd_base.s.period = 0;
> +	cmd_base.s.sensor_id = sensor_idx;
> +
> +	write64(0x0, privdata->mmio + AMD_C2P_MSG2);
> +	writel(cmd_base.ul, privdata->mmio + AMD_C2P_MSG0);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(amd_stop_sensor);
> +
> +int amd_stop_all_sensors(struct pci_dev *pdev)
> +{
> +	struct amd_mp2_dev *privdata = pci_get_drvdata(pdev);
> +	union sfh_cmd_base cmd_base;
> +
> +	/*fill up command register */
> +	cmd_base.ul = 0;
> +	cmd_base.s.cmd_id = stop_all_sensors;
> +	cmd_base.s.period = 0;
> +	cmd_base.s.sensor_id = 0;
> +
> +	writel(cmd_base.ul, privdata->mmio + AMD_C2P_MSG0);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(amd_stop_all_sensors);
> +
> +int amd_mp2_get_sensor_num(struct pci_dev *dev, u8 *sensor_id)
> +{
> +	struct amd_mp2_dev *privdata = pci_get_drvdata(dev);
> +	int activestatus;
> +	int num_of_sensors = 0;
> +
> +	if (!sensor_id)
> +		return -ENOMEM;
> +
> +	privdata->eventreg.activecontrolstatus =
> +			readl(privdata->mmio + AMD_P2C_MSG3);
> +	activestatus = privdata->eventreg.activecontrolstatus >> 4;
> +
> +	if (ACEL_EN  & activestatus) {
> +		sensor_id[num_of_sensors] = ACCEL_IDX;
> +		num_of_sensors++;
> +	}
> +	if (GYRO_EN & activestatus) {
> +		sensor_id[num_of_sensors] = GYRO_IDX;
> +		num_of_sensors++;
> +	}
> +	if (MAGNO_EN & activestatus) {
> +		sensor_id[num_of_sensors] = MAG_IDX;
> +		num_of_sensors++;
> +	}
> +
> +	if (ALS_EN & activestatus) {
> +		sensor_id[num_of_sensors] = AMBIENT_LIGHT_IDX;
> +		num_of_sensors++;
> +	}
> +
> +	return num_of_sensors;
> +}
> +EXPORT_SYMBOL_GPL(amd_mp2_get_sensor_num);
> +
> +static int amd_mp2_pci_init(struct amd_mp2_dev *privdata, struct
> pci_dev *pdev)
> +{
> +	int rc;
> +	int bar_index = 2;
> +	resource_size_t size, base;
> +
> +	pci_set_drvdata(pdev, privdata);
> +
> +	rc = pci_enable_device(pdev);
> +	if (rc)
> +		goto err_pci_enable;
> +
> +	rc = pci_request_regions(pdev, DRIVER_NAME);
> +	if (rc)
> +		goto err_pci_regions;
> +
> +	pci_set_master(pdev);
> +
> +	rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
> +	if (rc) {
> +		rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
> +		if (rc)
> +			goto err_dma_mask;
> +		dev_warn(ndev_dev(privdata), "Cannot DMA highmem\n");
If rc, you are returning from the function. Why dev_Warn?

> +	}
> +
> +	rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
> +	if (rc) {
> +		rc = pci_set_consistent_dma_mask(pdev,
> DMA_BIT_MASK(32));
> +		if (rc)
> +			goto err_dma_mask;
> +		dev_warn(ndev_dev(privdata), "Cannot DMA consistent
> highmem\n");
Why dev_warn?

> +	}
> +
> +	base = pci_resource_start(pdev, bar_index);
> +	size = pci_resource_len(pdev, bar_index);
> +	dev_dbg(ndev_dev(privdata), "Base addr:%llx size:%llx\n",
> +		(unsigned long long)base, (unsigned long long)size);
> +	privdata->mmio = ioremap(base, size);
> +	if (!privdata->mmio) {
> +		rc = -EIO;
> +		goto err_dma_mask;
> +	}
> +
> +	return 0;
> +
> +err_dma_mask:
> +	pci_clear_master(pdev);
> +	pci_release_regions(pdev);
> +err_pci_regions:
> +	pci_disable_device(pdev);
> +err_pci_enable:
> +	pci_set_drvdata(pdev, NULL);
> +	return rc;
> +}
> +
> +static void amd_mp2_pci_deinit(struct amd_mp2_dev *privdata)
> +{
> +	struct pci_dev *pdev = ndev_pdev(privdata);
> +
> +	amd_stop_all_sensors(pdev);
> +	pci_iounmap(pdev, privdata->mmio);
> +
> +	pci_clear_master(pdev);
> +	pci_release_regions(pdev);
> +	pci_disable_device(pdev);
> +	pci_set_drvdata(pdev, NULL);
> +}
> +
> +static int amd_mp2_pci_probe(struct pci_dev *pdev,
> +			     const struct pci_device_id *id)
> +{
> +	struct amd_mp2_dev *privdata;
> +	int rc;
> +
> +	dev_info(&pdev->dev, "MP2 device found [%04x:%04x] (rev %x)\n",
> +		 (int)pdev->vendor, (int)pdev->device, (int)pdev-
> >revision);
Better dev_dbg. On the most of the distro kernel, you will see this
message in dmesg, even if you don't need unless debugging.

> +
> +	privdata = kzalloc(sizeof(*privdata), GFP_KERNEL);
> 
> +
> +	if (!privdata) {
> +		rc = -ENOMEM;
> +		goto err_dev;
> +	}
> +
> +	privdata->pdev = pdev;
> +
> +	rc = amd_mp2_pci_init(privdata, pdev);
> +	if (rc)
> +		goto err_pci_init;
> +
> +	return 0;
> +
> +err_pci_init:
> +	kfree(privdata);
> +err_dev:
> +	dev_err(&pdev->dev, "Memory Allocation Failed\n");
You don't need memory allocation failure error, there are other prints
will show this.

> +	return rc;
> +}
> +
> +static void amd_mp2_pci_remove(struct pci_dev *pdev)
> +{
> +	struct amd_mp2_dev *privdata = pci_get_drvdata(pdev);
> +
> +	amd_mp2_pci_deinit(privdata);
> +	kfree(privdata);
> +}
> +
> +static const struct pci_device_id amd_mp2_pci_tbl[] = {
> +	{PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_MP2)},
> +	{0}
> +};
> +MODULE_DEVICE_TABLE(pci, amd_mp2_pci_tbl);
> +
> +static struct pci_driver amd_mp2_pci_driver = {
> +	.name		= DRIVER_NAME,
> +	.id_table	= amd_mp2_pci_tbl,
> +	.probe		= amd_mp2_pci_probe,
> +	.remove		= amd_mp2_pci_remove,
> +};
> +
> +static int __init amd_mp2_pci_driver_init(void)
> +{
> +	return pci_register_driver(&amd_mp2_pci_driver);
> +}
> +module_init(amd_mp2_pci_driver_init);
> +
> +static void __exit amd_mp2_pci_driver_exit(void)
> +{
> +	pci_unregister_driver(&amd_mp2_pci_driver);
> +}
> +module_exit(amd_mp2_pci_driver_exit);
> +MODULE_DESCRIPTION(DRIVER_DESC);
> +MODULE_VERSION(DRIVER_VER);
> +MODULE_LICENSE("Dual BSD/GPL");
> +MODULE_AUTHOR("Shyam Sundar S K <Shyam-sundar.S-k@....com>");
> +MODULE_AUTHOR("Nehal Bakulchandra Shah <
> Nehal-bakulchandra.Shah@....com>");
> diff --git a/drivers/hid/amd-sfh-hid/amd_mp2_pcie.h
> b/drivers/hid/amd-sfh-hid/amd_mp2_pcie.h
> new file mode 100644
> index 0000000..2bfd2de
> --- /dev/null
> +++ b/drivers/hid/amd-sfh-hid/amd_mp2_pcie.h
> @@ -0,0 +1,169 @@
> +/* SPDX-License-Identifier: GPL-2.0
> + *
> + * AMD MP2 PCIe communication driver
> + *
> + * Authors: Shyam Sundar S K <Shyam-sundar.S-k@....com>
> + *          Nehal Bakulchandra Shah <Nehal-bakulchandra.Shah@....com
> >
> + */
> +
> +#ifndef PCIE_MP2_AMD_H
> +#define PCIE_MP2_AMD_H
> +
> +#include <linux/pci.h>
> +#define PCI_DEVICE_ID_AMD_MP2	0x15E4
> +
> +#define write64 _write64
When you are defining a special write64, better to prefix with
something. This way this will not be confused with some API.
Same for read64.

> +static inline void _write64(u64 val, void __iomem *mmio)
> +{
> +	writel(val, mmio);
> +	writel(val >> 32, mmio + sizeof(u32));
> +}
> +
> +#define read64 _read64
> +static inline u64 _read64(void __iomem *mmio)
> +{
> +	u64 low, high;
> +
> +	low = readl(mmio);
> +	high = readl(mmio + sizeof(u32));
> +	return low | (high << 32);
> +}
> +
> +enum {
> +	/* MP2 C2P Message Registers */
> +	AMD_C2P_MSG0 = 0x10500,
> +	AMD_C2P_MSG1 = 0x10504,
> +	AMD_C2P_MSG2 = 0x10508,
> +	AMD_C2P_MSG3 = 0x1050c,
> +	AMD_C2P_MSG4 = 0x10510,
> +	AMD_C2P_MSG5 = 0x10514,
> +	AMD_C2P_MSG6 = 0x10518,
> +	AMD_C2P_MSG7 = 0x1051c,
> +	AMD_C2P_MSG8 = 0x10520,
> +	AMD_C2P_MSG9 = 0x10524,
> +
> +	/* MP2 P2C Message Registers */
> +	AMD_P2C_MSG0 = 0x10680, /*Do not use*/
> +	AMD_P2C_MSG1 = 0x10684,
> +	AMD_P2C_MSG2 = 0x10688,
> +	AMD_P2C_MSG3 = 0x1068C, /*MP2 debug info*/
> +	AMD_P2C_MSG_INTEN = 0x10690, /*MP2 int gen register*/
> +	AMD_P2C_MSG_INTSTS = 0x10694, /*Interrupt sts*/
> +};
Why not #define, when you are overriding every enum?

> +
> +/*
> + * SFH Command registers
> + */
> +union sfh_cmd_base {
> +	u32 ul;
> +	struct {
> +		u32 cmd_id : 8;
> +		u32 sensor_id : 8;
> +		u32 period : 16;
> +	} s; /*!< Structure used for bit access */
> +};
> +
> +union sfh_command_parameter {
> +	u32 ul;
> +	struct {
> +		u32 buffer_layout : 2;
> +		u32 buffer_length : 6;
> +		u32 rsvd : 24;
> +	} s;
> +};
> +
> +struct sfh_command_register {
> +	union sfh_cmd_base cmd_base;
> +	union sfh_command_parameter cmd_param;
> +	phys_addr_t phy_addr;
> +};
> +
> +/*
> + * SFH Response registers
> + */
> +enum response_type {
> +	non_operationevent,
> +	command_success,
> +	command_failed,
> +	sfi_dataready_event,
> +	invalid_response = 0xff,
> +};
> +
> +enum status_type {
> +	cmd_success,
> +	invalid_data_payload,
> +	invalid_data_length,
> +	invalid_sensor_id,
> +	invalid_dram_addr,
> +	invalid_command,
> +	sensor_enabled,
> +	sensor_disabled,
> +	status_end,
> +};
> +
> +enum command_id {
> +	non_operation = 0,
> +	enable_sensor = 1,
> +	disable_sensor = 2,
> +	dump_sensorinfo = 3,
> +	numberof_sensordiscovered = 4,
> +	who_am_i_regchipid = 5,
> +	set_dcd_data = 6,
> +	get_dcd_data = 7,
> +	stop_all_sensors = 8,
> +	invalid_cmd = 0xf,
> +};
> +
> +union sfh_event_base {
> +	u32 ul;
> +	struct {
Since you are explaining every member, better to use kerneldoc style

Thanks,
Srinivas

> +		u32 response : 4; /*!< bit: 0..3 SFI response_type */
> +		u32 status : 3; /*!< bit: 6..5 status_type */
> +		u32 out_in_c2p : 1; /*!< bit: 5 0- output in DRAM,1-in
> C2PMsg */
> +		u32 length : 6; /*!< bit: 8..13 length */
> +		u32 dbg : 2; /*!< bit: 14.15 dbg msg include in p2c msg
> 1-2 */
> +		u32 sensor_id : 8; /*!< bit: 16..23 Sensor ID */
> +		u32 rsvd : 8; /*!< bit: 24..31 Reservered for future
> use */
> +	} s;
> +};
> +
> +struct sfi_event_register {
> +	union sfh_event_base evtbase;
> +	u32 debuginfo1;
> +	u32 debuginfo2;
> +	u32 activecontrolstatus;
> +};
> +
> +enum sensor_idx {
> +	ACCEL_IDX               = 0,
> +	GYRO_IDX                = 1,
> +	MAG_IDX                 = 2,
> +	AMBIENT_LIGHT_IDX       = 19,
> +	NUM_ALL_SENSOR_CONSUMERS
> +};
> +
> +struct amd_mp2_dev {
> +	struct pci_dev *pdev;
> +	struct dentry *debugfs_dir;
> +	void __iomem *mmio;
> +	union sfh_event_base eventval;
> +	struct sfi_event_register eventreg;
> +	struct delayed_work work;
> +	void *ctx;
> +	void *cl_data;
> +};
> +
> +struct amd_mp2_sensor_info {
> +	u8 sensor_idx;
> +	u32 period;
> +	phys_addr_t phy_address;
> +};
> +
> +int amd_start_sensor(struct pci_dev *pdev, struct
> amd_mp2_sensor_info info);
> +int amd_stop_sensor(struct pci_dev *pdev, u16 sensor_idx);
> +int amd_stop_all_sensors(struct pci_dev *pdev);
> +int amd_mp2_get_sensor_num(struct pci_dev *dev, u8 *sensor_id);
> +#define ndev_pdev(ndev) ((ndev)->pdev)
> +#define ndev_name(ndev) pci_name(ndev_pdev(ndev))
> +#define ndev_dev(ndev) (&ndev_pdev(ndev)->dev)
> +#endif

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