Re: [PATCH v2 2/4] mfd: intel-m10-bmc: split into core and spi

From: Xu Yilun
Date: Mon Jun 20 2022 - 06:06:51 EST


On Thu, Jun 16, 2022 at 10:04:03PM -0400, Tianfei Zhang wrote:
> Split the common code from intel-m10-bmc driver into intel-m10-bmc-core.
> intel-m10-bmc-core is the core MFD functions which can support multiple
> bus interfaces like SPI bus.

Please specify which else are you going to support, for better
understanding.

>
> Signed-off-by: Tianfei Zhang <tianfei.zhang@xxxxxxxxx>
> ---
> drivers/mfd/Kconfig | 30 +++---
> drivers/mfd/Makefile | 5 +-
> .../{intel-m10-bmc.c => intel-m10-bmc-core.c} | 101 +++++-------------
> drivers/mfd/intel-m10-bmc-spi.c | 83 ++++++++++++++
> include/linux/mfd/intel-m10-bmc.h | 15 +++
> 5 files changed, 144 insertions(+), 90 deletions(-)
> rename drivers/mfd/{intel-m10-bmc.c => intel-m10-bmc-core.c} (63%)
> create mode 100644 drivers/mfd/intel-m10-bmc-spi.c
>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 3b59456f5545..ee8398b02321 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -2158,18 +2158,24 @@ config SGI_MFD_IOC3
> If you have an SGI Origin, Octane, or a PCI IOC3 card,
> then say Y. Otherwise say N.
>
> -config MFD_INTEL_M10_BMC
> - tristate "Intel MAX 10 Board Management Controller"
> - depends on SPI_MASTER
> - select REGMAP_SPI_AVMM
> - select MFD_CORE
> - help
> - Support for the Intel MAX 10 board management controller using the
> - SPI interface.
> -
> - This driver provides common support for accessing the device,
> - additional drivers must be enabled in order to use the functionality
> - of the device.
> +config MFD_INTEL_M10_BMC_CORE
> + tristate
> + select MFD_CORE
> + select REGMAP
> + default n
> +
> +config MFD_INTEL_M10_BMC_SPI
> + tristate "Intel MAX 10 Board Management Controller with SPI"
> + depends on SPI_MASTER
> + select MFD_INTEL_M10_BMC_CORE
> + select REGMAP_SPI_AVMM
> + help
> + Support for the Intel MAX 10 board management controller using the
> + SPI interface.
> +
> + This driver provides common support for accessing the device,

device by SPI,

> + additional drivers must be enabled in order to use the functionality
> + of the device.
>
> config MFD_RSMU_I2C
> tristate "Renesas Synchronization Management Unit with I2C"
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 858cacf659d6..b5d3263c1205 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -266,7 +266,10 @@ obj-$(CONFIG_MFD_QCOM_PM8008) += qcom-pm8008.o
>
> obj-$(CONFIG_SGI_MFD_IOC3) += ioc3.o
> obj-$(CONFIG_MFD_SIMPLE_MFD_I2C) += simple-mfd-i2c.o
> -obj-$(CONFIG_MFD_INTEL_M10_BMC) += intel-m10-bmc.o
> +
> +intel-m10-bmc-objs := intel-m10-bmc-core.o
> +obj-$(CONFIG_MFD_INTEL_M10_BMC_CORE) += intel-m10-bmc.o

Why make a intel-m10-bmc obj here? What's the problem of
intel-m10-bmc-core.o?

> +obj-$(CONFIG_MFD_INTEL_M10_BMC_SPI) += intel-m10-bmc-spi.o
>
> obj-$(CONFIG_MFD_ATC260X) += atc260x-core.o
> obj-$(CONFIG_MFD_ATC260X_I2C) += atc260x-i2c.o
> diff --git a/drivers/mfd/intel-m10-bmc.c b/drivers/mfd/intel-m10-bmc-core.c
> similarity index 63%
> rename from drivers/mfd/intel-m10-bmc.c
> rename to drivers/mfd/intel-m10-bmc-core.c
> index 7e521df29c72..f6dc549e1bc3 100644
> --- a/drivers/mfd/intel-m10-bmc.c
> +++ b/drivers/mfd/intel-m10-bmc-core.c
> @@ -1,23 +1,14 @@
> // SPDX-License-Identifier: GPL-2.0
> /*
> - * Intel MAX 10 Board Management Controller chip
> + * Intel MAX 10 Board Management Controller chip - common code
> *
> - * Copyright (C) 2018-2020 Intel Corporation. All rights reserved.
> + * Copyright (C) 2018-2022 Intel Corporation. All rights reserved.
> */
> #include <linux/bitfield.h>
> #include <linux/init.h>
> #include <linux/mfd/core.h>
> #include <linux/mfd/intel-m10-bmc.h>
> #include <linux/module.h>
> -#include <linux/mutex.h>
> -#include <linux/regmap.h>
> -#include <linux/spi/spi.h>
> -
> -enum m10bmc_type {
> - M10_N3000,
> - M10_D5005,
> - M10_N5010,
> -};
>
> static struct mfd_cell m10bmc_d5005_subdevs[] = {
> { .name = "d5005bmc-hwmon" },
> @@ -33,26 +24,6 @@ static struct mfd_cell m10bmc_n5010_subdevs[] = {
> { .name = "n5010bmc-hwmon" },
> };
>
> -static const struct regmap_range m10bmc_regmap_range[] = {
> - regmap_reg_range(M10BMC_LEGACY_BUILD_VER, M10BMC_LEGACY_BUILD_VER),
> - regmap_reg_range(M10BMC_SYS_BASE, M10BMC_SYS_END),
> - regmap_reg_range(M10BMC_FLASH_BASE, M10BMC_FLASH_END),
> -};
> -
> -static const struct regmap_access_table m10bmc_access_table = {
> - .yes_ranges = m10bmc_regmap_range,
> - .n_yes_ranges = ARRAY_SIZE(m10bmc_regmap_range),
> -};
> -
> -static struct regmap_config intel_m10bmc_regmap_config = {
> - .reg_bits = 32,
> - .val_bits = 32,
> - .reg_stride = 4,
> - .wr_table = &m10bmc_access_table,
> - .rd_table = &m10bmc_access_table,
> - .max_register = M10BMC_MEM_END,
> -};

Why remove all these configurations, I suppose it is not related to bus
type.

> -
> static ssize_t bmc_version_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> @@ -131,7 +102,16 @@ static struct attribute *m10bmc_attrs[] = {
> &dev_attr_mac_count.attr,
> NULL,
> };
> -ATTRIBUTE_GROUPS(m10bmc);
> +
> +static const struct attribute_group m10bmc_group = {
> + .attrs = m10bmc_attrs,
> +};
> +
> +const struct attribute_group *m10bmc_dev_groups[] = {
> + &m10bmc_group,
> + NULL,
> +};
> +EXPORT_SYMBOL_GPL(m10bmc_dev_groups);
>
> static int check_m10bmc_version(struct intel_m10bmc *ddata)
> {
> @@ -158,37 +138,21 @@ static int check_m10bmc_version(struct intel_m10bmc *ddata)
> return 0;
> }
>
> -static int intel_m10_bmc_spi_probe(struct spi_device *spi)
> +int m10bmc_dev_init(struct intel_m10bmc *m10bmc)
> {
> - const struct spi_device_id *id = spi_get_device_id(spi);
> - struct device *dev = &spi->dev;
> + enum m10bmc_type type = m10bmc->type;
> struct mfd_cell *cells;
> - struct intel_m10bmc *ddata;
> int ret, n_cell;
>
> - ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
> - if (!ddata)
> - return -ENOMEM;
> -
> - ddata->dev = dev;
> -
> - ddata->regmap =
> - devm_regmap_init_spi_avmm(spi, &intel_m10bmc_regmap_config);
> - if (IS_ERR(ddata->regmap)) {
> - ret = PTR_ERR(ddata->regmap);
> - dev_err(dev, "Failed to allocate regmap: %d\n", ret);
> - return ret;
> - }
> -
> - spi_set_drvdata(spi, ddata);
> + dev_set_drvdata(m10bmc->dev, m10bmc);

The naming is not consistent here, some are ddata, some are m10bmc,
please keep a unified name acress all the patches.

>
> - ret = check_m10bmc_version(ddata);
> + ret = check_m10bmc_version(m10bmc);
> if (ret) {
> - dev_err(dev, "Failed to identify m10bmc hardware\n");
> + dev_err(m10bmc->dev, "Failed to identify m10bmc hardware\n");

Keep the dev local variable so that we don't have to change every
related lines.

> return ret;
> }
>
> - switch (id->driver_data) {
> + switch (type) {
> case M10_N3000:
> cells = m10bmc_pacn3000_subdevs;
> n_cell = ARRAY_SIZE(m10bmc_pacn3000_subdevs);
> @@ -205,33 +169,16 @@ static int intel_m10_bmc_spi_probe(struct spi_device *spi)
> return -ENODEV;
> }
>
> - ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, cells, n_cell,
> - NULL, 0, NULL);
> + ret = devm_mfd_add_devices(m10bmc->dev, PLATFORM_DEVID_AUTO,
> + cells, n_cell, NULL, 0, NULL);

ditto

> if (ret)
> - dev_err(dev, "Failed to register sub-devices: %d\n", ret);
> + dev_err(m10bmc->dev, "Failed to register sub-devices: %d\n",
> + ret);

ditto

>
> return ret;
> }
> +EXPORT_SYMBOL_GPL(m10bmc_dev_init);
>
> -static const struct spi_device_id m10bmc_spi_id[] = {
> - { "m10-n3000", M10_N3000 },
> - { "m10-d5005", M10_D5005 },
> - { "m10-n5010", M10_N5010 },
> - { }
> -};
> -MODULE_DEVICE_TABLE(spi, m10bmc_spi_id);
> -
> -static struct spi_driver intel_m10bmc_spi_driver = {
> - .driver = {
> - .name = "intel-m10-bmc",
> - .dev_groups = m10bmc_groups,
> - },
> - .probe = intel_m10_bmc_spi_probe,
> - .id_table = m10bmc_spi_id,
> -};
> -module_spi_driver(intel_m10bmc_spi_driver);
> -
> -MODULE_DESCRIPTION("Intel MAX 10 BMC Device Driver");
> +MODULE_DESCRIPTION("Intel MAX 10 BMC core MFD driver");
> MODULE_AUTHOR("Intel Corporation");
> MODULE_LICENSE("GPL v2");
> -MODULE_ALIAS("spi:intel-m10-bmc");
> diff --git a/drivers/mfd/intel-m10-bmc-spi.c b/drivers/mfd/intel-m10-bmc-spi.c
> new file mode 100644
> index 000000000000..9cafbc0f89f0
> --- /dev/null
> +++ b/drivers/mfd/intel-m10-bmc-spi.c
> @@ -0,0 +1,83 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Intel MAX 10 Board Management Controller chip

SPI driver for Intel MAX 10 ...

> + *
> + * Copyright (C) 2018-2021 Intel Corporation. All rights reserved.
> + */
> +#include <linux/bitfield.h>
> +#include <linux/init.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/intel-m10-bmc.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/spi/spi.h>
> +
> +static const struct regmap_range m10bmc_regmap_range[] = {
> + regmap_reg_range(M10BMC_LEGACY_BUILD_VER, M10BMC_LEGACY_BUILD_VER),
> + regmap_reg_range(M10BMC_SYS_BASE, M10BMC_SYS_END),
> + regmap_reg_range(M10BMC_FLASH_BASE, M10BMC_FLASH_END),
> +};
> +
> +static const struct regmap_access_table m10bmc_access_table = {
> + .yes_ranges = m10bmc_regmap_range,
> + .n_yes_ranges = ARRAY_SIZE(m10bmc_regmap_range),
> +};
> +
> +static struct regmap_config intel_m10bmc_regmap_config = {
> + .reg_bits = 32,
> + .val_bits = 32,
> + .reg_stride = 4,
> + .wr_table = &m10bmc_access_table,
> + .rd_table = &m10bmc_access_table,
> + .max_register = M10BMC_MEM_END,
> +};
> +
> +static int intel_m10_bmc_spi_probe(struct spi_device *spi)
> +{
> + const struct spi_device_id *id = spi_get_device_id(spi);
> + struct device *dev = &spi->dev;
> + struct intel_m10bmc *ddata;
> + int ret;
> +
> + ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
> + if (!ddata)
> + return -ENOMEM;
> +
> + ddata->dev = dev;
> + ddata->type = (enum m10bmc_type)(id->driver_data);
> +
> + ddata->regmap =
> + devm_regmap_init_spi_avmm(spi, &intel_m10bmc_regmap_config);
> + if (IS_ERR(ddata->regmap)) {
> + ret = PTR_ERR(ddata->regmap);
> + dev_err(dev, "Failed to allocate regmap: %d\n", ret);
> + return ret;
> + }
> +
> + spi_set_drvdata(spi, ddata);

Why we need this? I saw the dev.drvdata is set in core driver.

> +
> + return m10bmc_dev_init(ddata);
> +}
> +
> +static const struct spi_device_id m10bmc_spi_id[] = {
> + { "m10-n3000", M10_N3000 },
> + { "m10-d5005", M10_D5005 },
> + { "m10-n5010", M10_N5010 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(spi, m10bmc_spi_id);
> +
> +static struct spi_driver intel_m10bmc_spi_driver = {
> + .driver = {
> + .name = "intel-m10-bmc",

Need renaming?

> + .dev_groups = m10bmc_dev_groups,
> + },
> + .probe = intel_m10_bmc_spi_probe,
> + .id_table = m10bmc_spi_id,
> +};
> +module_spi_driver(intel_m10bmc_spi_driver);
> +
> +MODULE_DESCRIPTION("Intel MAX 10 BMC SPI bus interface");
> +MODULE_AUTHOR("Intel Corporation");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("spi:intel-m10-bmc");
> diff --git a/include/linux/mfd/intel-m10-bmc.h b/include/linux/mfd/intel-m10-bmc.h
> index f0044b14136e..dd81ffdcf168 100644
> --- a/include/linux/mfd/intel-m10-bmc.h
> +++ b/include/linux/mfd/intel-m10-bmc.h
> @@ -118,14 +118,23 @@
> /* Address of 4KB inverted bit vector containing staging area FLASH count */
> #define STAGING_FLASH_COUNT 0x17ffb000
>
> +/* Supported MAX10 BMC types */

Please use correct format for kernel doc comments

> +enum m10bmc_type {
> + M10_N3000,
> + M10_D5005,
> + M10_N5010,
> +};
> +
> /**
> * struct intel_m10bmc - Intel MAX 10 BMC parent driver data structure
> * @dev: this device
> * @regmap: the regmap used to access registers by m10bmc itself
> + * @type: the type of MAX10 BMC
> */
> struct intel_m10bmc {
> struct device *dev;
> struct regmap *regmap;
> + enum m10bmc_type type;
> };
>
> /*
> @@ -159,4 +168,10 @@ m10bmc_raw_read(struct intel_m10bmc *m10bmc, unsigned int addr,
> #define m10bmc_sys_read(m10bmc, offset, val) \
> m10bmc_raw_read(m10bmc, M10BMC_SYS_BASE + (offset), val)
>
> +/*
> + * MAX10 BMC Core support
> + */
> +int m10bmc_dev_init(struct intel_m10bmc *m10bmc);
> +extern const struct attribute_group *m10bmc_dev_groups[];
> +
> #endif /* __MFD_INTEL_M10_BMC_H */
> --
> 2.26.2