RE: [patch v2] x86/platform/mellanox: introduce support for Mellanox systems platform

[Vadim Pasternak]

> -----Original Message-----
> From: Guenter Roeck [mailto:linux@xxxxxxxxxxxx]
> Sent: Monday, September 19, 2016 9:03 AM
> To: Vadim Pasternak <vadimp@xxxxxxxxxxxx>; tglx@xxxxxxxxxxxxx
> Cc: mingo@xxxxxxxxxx; hpa@xxxxxxxxx; davem@xxxxxxxxxxxxx; geert@linux-
> m68k.org; akpm@xxxxxxxxxxxxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx;
> kvalo@xxxxxxxxxxxxxx; mchehab@xxxxxxxxxx; x86@xxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; platform-driver-x86@xxxxxxxxxxxxxxx; jiri@xxxxxxxxxxx
> Subject: Re: [patch v2] x86/platform/mellanox: introduce support for Mellanox
> systems platform
> 
> On 09/15/2016 02:55 AM, vadimp@xxxxxxxxxxxx wrote:
> > From: Vadim Pasternak <vadimp@xxxxxxxxxxxx>
> >
> > Enable system support for the Mellanox Technologies platform, which
> > provides support for the next Mellanox basic systems: "msx6710",
> > "msx6720", "msb7700", "msn2700", "msx1410", "msn2410", "msb7800",
> > "msn2740", "msn2100" and also various number of derivative systems
> > from the above basic types.
> >
> > The Kconfig currently controlling compilation of this code is:
> > arch/x86/platform:config MLX_PLATFORM
> > arch/x86/platform:      tristate "Mellanox Technologies platform support"
> >
> > Signed-off-by: Vadim Pasternak <vadimp@xxxxxxxxxxxx>
> > ---
> > v1->v2:
> >  Comments pointed out by Greg:
> >   - kick out all PCI related code;
> > ---
> >  MAINTAINERS                               |   7 +
> >  arch/x86/Kconfig                          |  25 +++
> >  arch/x86/platform/Makefile                |   1 +
> >  arch/x86/platform/mellanox/Makefile       |   1 +
> >  arch/x86/platform/mellanox/mlx-platform.c | 275
> > ++++++++++++++++++++++++++++++
> >  5 files changed, 309 insertions(+)
> >  create mode 100644 arch/x86/platform/mellanox/Makefile
> >  create mode 100644 arch/x86/platform/mellanox/mlx-platform.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS index 4705c94..8a675de 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -7664,6 +7664,13 @@ W:	http://www.mellanox.com
> >  Q:	http://patchwork.ozlabs.org/project/netdev/list/
> >  F:	drivers/net/ethernet/mellanox/mlxsw/
> >
> > +MELLANOX PLATFORM DRIVER
> > +M:      Vadim Pasternak <vadimp@xxxxxxxxxxxx>
> > +L:      platform-driver-x86@xxxxxxxxxxxxxxx
> > +S:      Supported
> > +W:      http://www.mellanox.com
> > +F:      arch/x86/platform/mellanox/mlx-platform.c
> > +
> >  SOFT-ROCE DRIVER (rxe)
> >  M:	Moni Shoua <monis@xxxxxxxxxxxx>
> >  L:	linux-rdma@xxxxxxxxxxxxxxx
> > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index
> > c580d8c..1346441 100644
> > --- a/arch/x86/Kconfig
> > +++ b/arch/x86/Kconfig
> > @@ -550,6 +550,31 @@ config X86_INTEL_QUARK
> >  	  Say Y here if you have a Quark based system such as the Arduino
> >  	  compatible Intel Galileo.
> >
> > +config MLX_PLATFORM
> > +	tristate "Mellanox Technologies platform support"
> > +	depends on X86_64
> > +	depends on X86_EXTENDED_PLATFORM
> > +	depends on PCI
> 
> No longer needed.
> 
> > +	depends on DMI
> > +	depends on I2C_MLXCPLD
> > +	depends on I2C_MUX_REG
> > +	select HWMON
> > +	select PMBUS
> > +	select SENSORS_PMBUS
> > +	select LM75
> > +	select NEW_LEDS
> > +	select LEDS_CLASS
> > +	select LEDS_TRIGGERS
> > +	select LEDS_TRIGGER_TIMER
> > +	select LEDS_MLXCPLD
> 
> Kind of unusual to select drivers not directly related to this one like this.

These selection is required by all systems.
Do you suggest to remove all that is not related directly?

> 
> > +	---help---
> > +	  This option enables system support for the Mellanox Technologies
> > +	  platform.
> > +
> > +	  Say Y here if you are building a kernel for Mellanox system.
> > +
> > +	  Otherwise, say N.
> > +
> >  config X86_INTEL_LPSS
> >  	bool "Intel Low Power Subsystem Support"
> >  	depends on X86 && ACPI
> > diff --git a/arch/x86/platform/Makefile b/arch/x86/platform/Makefile
> > index 184842e..3c3c19e 100644
> > --- a/arch/x86/platform/Makefile
> > +++ b/arch/x86/platform/Makefile
> > @@ -8,6 +8,7 @@ obj-y	+= iris/
> >  obj-y	+= intel/
> >  obj-y	+= intel-mid/
> >  obj-y	+= intel-quark/
> > +obj-y	+= mellanox/
> >  obj-y	+= olpc/
> >  obj-y	+= scx200/
> >  obj-y	+= sfi/
> > diff --git a/arch/x86/platform/mellanox/Makefile
> > b/arch/x86/platform/mellanox/Makefile
> > new file mode 100644
> > index 0000000..f43c931
> > --- /dev/null
> > +++ b/arch/x86/platform/mellanox/Makefile
> > @@ -0,0 +1 @@
> > +obj-$(CONFIG_MLX_PLATFORM)	+= mlx-platform.o
> > diff --git a/arch/x86/platform/mellanox/mlx-platform.c
> > b/arch/x86/platform/mellanox/mlx-platform.c
> > new file mode 100644
> > index 0000000..d29da68
> > --- /dev/null
> > +++ b/arch/x86/platform/mellanox/mlx-platform.c
> > @@ -0,0 +1,275 @@
> > +/*
> > + * arch/x86/platform/mellanox/mlx-platform.c
> > + * Copyright (c) 2016 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2016 Vadim Pasternak <vadimp@xxxxxxxxxxxx>
> > + *
> > + * Redistribution and use in source and binary forms, with or without
> > + * modification, are permitted provided that the following conditions are
> met:
> > + *
> > + * 1. Redistributions of source code must retain the above copyright
> > + *    notice, this list of conditions and the following disclaimer.
> > + * 2. Redistributions in binary form must reproduce the above copyright
> > + *    notice, this list of conditions and the following disclaimer in the
> > + *    documentation and/or other materials provided with the distribution.
> > + * 3. Neither the names of the copyright holders nor the names of its
> > + *    contributors may be used to endorse or promote products derived from
> > + *    this software without specific prior written permission.
> > + *
> > + * Alternatively, this software may be distributed under the terms of
> > +the
> > + * GNU General Public License ("GPL") version 2 as published by the
> > +Free
> > + * Software Foundation.
> > + *
> > + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
> CONTRIBUTORS "AS IS"
> > + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
> LIMITED
> > +TO, THE
> > + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
> PARTICULAR
> > +PURPOSE
> > + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
> > +CONTRIBUTORS BE
> > + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
> > +OR
> > + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
> PROCUREMENT
> > +OF
> > + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
> > +BUSINESS
> > + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
> > +WHETHER IN
> > + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
> > +OTHERWISE)
> > + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
> > +ADVISED OF THE
> > + * POSSIBILITY OF SUCH DAMAGE.
> > + */
> > +
> > +#include <linux/device.h>
> > +#include <linux/dmi.h>
> > +#include <linux/i2c.h>
> > +#include <linux/i2c-mux.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/platform_data/i2c-mux-reg.h>
> > +
> > +#define MLX_PLAT_DEVICE_NAME		"mlxplat"
> > +
> > +/* LPC bus IO offsets */
> > +#define MLXPLAT_CPLD_LPC_I2C_BASE_ADRR		0x2000
> > +#define MLXPLAT_CPLD_LPC_REG_BASE_ADRR		0x2500
> > +#define MLXPLAT_CPLD_LPC_IO_RANGE		0x100
> > +#define MLXPLAT_CPLD_LPC_I2C_CH1_OFF		0xdb
> > +#define MLXPLAT_CPLD_LPC_I2C_CH2_OFF		0xda
> > +#define MLXPLAT_CPLD_LPC_PIO_OFFSET		0x10000UL
> > +#define MLXPLAT_CPLD_LPC_REG1
> 	((MLXPLAT_CPLD_LPC_REG_BASE_ADRR + \
> > +				  MLXPLAT_CPLD_LPC_I2C_CH1_OFF) | \
> > +				  MLXPLAT_CPLD_LPC_PIO_OFFSET)
> > +#define MLXPLAT_CPLD_LPC_REG2
> 	((MLXPLAT_CPLD_LPC_REG_BASE_ADRR + \
> > +				  MLXPLAT_CPLD_LPC_I2C_CH2_OFF) | \
> > +				  MLXPLAT_CPLD_LPC_PIO_OFFSET)
> > +
> > +/* Start channel numbers */
> > +#define MLXPLAT_CPLD_CH1			2
> > +#define MLXPLAT_CPLD_CH2			10
> > +
> > +/* Number of LPC attached MUX platform devices */
> > +#define MLXPLAT_CPLD_LPC_MUX_DEVS		2
> > +
> > +/* mlxplat_priv - platform private data
> > + * @pdev_i2c - i2c controller platform device
> > + * @pdev_mux - array of mux platform devices  */ struct mlxplat_priv
> > +{
> > +	struct platform_device *pdev_i2c;
> > +	struct platform_device *pdev_mux[MLXPLAT_CPLD_LPC_MUX_DEVS];
> > +};
> > +
> > +/* Regions for LPC I2C controller and LPC base register space */
> > +static struct resource mlxplat_lpc_resources[] = {
> > +	[0] = DEFINE_RES_NAMED(MLXPLAT_CPLD_LPC_I2C_BASE_ADRR,
> > +			       MLXPLAT_CPLD_LPC_IO_RANGE,
> > +			       "mlxplat_cpld_lpc_i2c_ctrl", IORESOURCE_IO),
> > +	[1] = DEFINE_RES_NAMED(MLXPLAT_CPLD_LPC_REG_BASE_ADRR,
> > +			       MLXPLAT_CPLD_LPC_IO_RANGE,
> > +			       "mlxplat_cpld_lpc_regs",
> > +			       IORESOURCE_IO),
> > +};
> > +
> > +/* Platform default channels */
> > +static int mlxplat_default_channels[][8] = {
> > +	{
> > +		MLXPLAT_CPLD_CH1, MLXPLAT_CPLD_CH1 + 1,
> MLXPLAT_CPLD_CH1 + 2,
> > +		MLXPLAT_CPLD_CH1 + 3, MLXPLAT_CPLD_CH1 + 4,
> MLXPLAT_CPLD_CH1 +
> > +		5, MLXPLAT_CPLD_CH1 + 6, MLXPLAT_CPLD_CH1 + 7
> > +	},
> > +	{
> > +		MLXPLAT_CPLD_CH2, MLXPLAT_CPLD_CH2 + 1,
> MLXPLAT_CPLD_CH2 + 2,
> > +		MLXPLAT_CPLD_CH2 + 3, MLXPLAT_CPLD_CH2 + 4,
> MLXPLAT_CPLD_CH2 +
> 
> Odd line split.
> 
> > +		+ 5, MLXPLAT_CPLD_CH2 + 6, MLXPLAT_CPLD_CH2 + 7
> > +	},
> > +};
> > +
> > +/* Platform channels for MSN21xx system family */ static int
> > +mlxplat_msn21xx_channels[][8] = {
> > +	{
> > +		1, 2, 3, 4, 5, 6, 7, 8
> > +	},
> > +	{
> > +		1, 2, 3, 4, 5, 6, 7, 8
> > +	},
> 
> Seems to be a waste. A single dimensional array should be sufficient.
> 
OK

> > +};
> > +
> > +/* Platform mux data */
> > +struct i2c_mux_reg_platform_data mlxplat_mux_data[] = {
> 
> Why global ?
> 
> > +	{
> > +		.parent = 1,
> > +		.base_nr = MLXPLAT_CPLD_CH1,
> > +		.write_only = 1,
> > +		.reg = (void __iomem *)MLXPLAT_CPLD_LPC_REG1,
> > +		.reg_size = 1,
> > +		.idle_in_use = 1,
> > +	},
> > +	{
> > +		.parent = 1,
> > +		.base_nr = MLXPLAT_CPLD_CH2,
> > +		.write_only = 1,
> > +		.reg = (void __iomem *)MLXPLAT_CPLD_LPC_REG2,
> > +		.reg_size = 1,
> > +		.idle_in_use = 1,
> > +	},
> > +
> > +};
> > +
> > +struct platform_device *mlxplat_dev;
> > +
> 
> Is this global on purpose ? If so, why ?

No, it should be both static.

> 
> > +static int __init mlxplat_dmi_default_matched(const struct
> > +dmi_system_id *dmi) {
> > +	int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(mlxplat_mux_data); i++) {
> > +		mlxplat_mux_data[i].values = mlxplat_default_channels[i];
> > +		mlxplat_mux_data[i].n_values =
> > +				ARRAY_SIZE(mlxplat_default_channels[i]);
> > +	}
> > +
> > +	return 1;
> > +};
> > +
> > +static int __init mlxplat_dmi_msn21xx_matched(const struct
> > +dmi_system_id *dmi) {
> > +	int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(mlxplat_mux_data); i++) {
> > +		mlxplat_mux_data[i].values = mlxplat_msn21xx_channels[i],
> > +		mlxplat_mux_data[i].n_values =
> > +				ARRAY_SIZE(mlxplat_msn21xx_channels[i]);
> > +	}
> > +
> > +	return 1;
> > +};
> > +
> > +static struct dmi_system_id mlxplat_dmi_table[] __initdata = {
> > +	{
> > +		.callback = mlxplat_dmi_default_matched,
> > +		.matches = {
> > +			DMI_MATCH(DMI_BOARD_VENDOR, "Mellanox
> Technologies"),
> > +			DMI_MATCH(DMI_PRODUCT_NAME, "MSN24"),
> > +		},
> > +	},
> > +	{
> > +		.callback = mlxplat_dmi_default_matched,
> > +		.matches = {
> > +			DMI_MATCH(DMI_BOARD_VENDOR, "Mellanox
> Technologies"),
> > +			DMI_MATCH(DMI_PRODUCT_NAME, "MSN27"),
> > +		},
> > +	},
> > +	{
> > +		.callback = mlxplat_dmi_default_matched,
> > +		.matches = {
> > +			DMI_MATCH(DMI_BOARD_VENDOR, "Mellanox
> Technologies"),
> > +			DMI_MATCH(DMI_PRODUCT_NAME, "MSB"),
> > +		},
> > +	},
> > +	{
> > +		.callback = mlxplat_dmi_default_matched,
> > +		.matches = {
> > +			DMI_MATCH(DMI_BOARD_VENDOR, "Mellanox
> Technologies"),
> > +			DMI_MATCH(DMI_PRODUCT_NAME, "MSX"),
> > +		},
> > +	},
> > +	{
> > +		.callback = mlxplat_dmi_msn21xx_matched,
> > +		.matches = {
> > +			DMI_MATCH(DMI_BOARD_VENDOR, "Mellanox
> Technologies"),
> > +			DMI_MATCH(DMI_PRODUCT_NAME, "MSN21"),
> > +		},
> > +	},
> > +	{ }
> > +};
> > +
> > +static int __init mlxplat_init(void)
> > +{
> > +	struct mlxplat_priv *priv;
> > +	int i;
> > +	int err;
> > +
> > +	if (!dmi_check_system(mlxplat_dmi_table))
> > +		return -ENODEV;
> > +
> > +	mlxplat_dev =
> platform_device_register_simple(MLX_PLAT_DEVICE_NAME, -1,
> > +					mlxplat_lpc_resources,
> > +					ARRAY_SIZE(mlxplat_lpc_resources));
> > +
> > +	if (!mlxplat_dev) {
> > +		pr_err("Alloc %s platform device failed\n",
> > +			MLX_PLAT_DEVICE_NAME);
> 
> Error messages for memory allocations are unnecessary.
> 
> > +		return -ENOMEM;
> > +	}
> > +
> > +	priv = devm_kzalloc(&mlxplat_dev->dev, sizeof(struct mlxplat_priv),
> > +			    GFP_KERNEL);
> > +	if (!priv) {
> > +		err = -ENOMEM;
> > +		dev_err(&mlxplat_dev->dev, "Failed to allocate
> mlxplat_priv\n");
> 
> Same here.
> 
> > +		goto fail_alloc;
> > +	}
> > +	platform_set_drvdata(mlxplat_dev, priv);
> > +
> > +	priv->pdev_i2c = platform_device_register_simple("i2c_mlxcpld", -1,
> > +							 NULL, 0);
> > +	if (IS_ERR(priv->pdev_i2c)) {
> > +		err = PTR_ERR(priv->pdev_i2c);
> > +		goto fail_alloc;
> > +	};
> > +
> > +	for (i = 0; i < ARRAY_SIZE(mlxplat_mux_data); i++) {
> > +		priv->pdev_mux[i] = platform_device_register_resndata(
> > +						&mlxplat_dev->dev,
> > +						"i2c-mux-reg", i, NULL,
> > +						0, &mlxplat_mux_data[i],
> > +						sizeof(mlxplat_mux_data[i]));
> > +		if (IS_ERR(priv->pdev_mux[i])) {
> > +			err = PTR_ERR(priv->pdev_mux[i]);
> > +			goto fail_platform_mux_register;
> > +		}
> > +	}
> > +
> > +	return err;
> 
> return 0;
> 
> > +
> > +fail_platform_mux_register:
> > +	for (i--; i > 0 ; i--)
> 
>  >= 0 ?
> 
> > +		platform_device_unregister(priv->pdev_mux[i]);
> > +	platform_device_unregister(priv->pdev_i2c);
> > +fail_alloc:
> > +	platform_device_unregister(mlxplat_dev);
> > +
> > +	return err;
> > +}
> > +
> > +static void __exit mlxplat_exit(void) {
> > +	struct mlxplat_priv *priv = platform_get_drvdata(mlxplat_dev);
> > +	int i;
> > +
> > +	for (i = ARRAY_SIZE(mlxplat_mux_data) - 1; i >= 0 ; i--)
> > +		platform_device_unregister(priv->pdev_mux[i]);
> > +
> > +	platform_device_unregister(priv->pdev_i2c);
> > +	platform_device_unregister(mlxplat_dev);
> > +}
> > +
> > +module_init(mlxplat_init);
> > +module_exit(mlxplat_exit);
> > +
> > +MODULE_AUTHOR("Vadim Pasternak (vadimp@xxxxxxxxxxxx)");
> > +MODULE_DESCRIPTION("Mellanox platform driver");
> MODULE_LICENSE("GPL
> > +v2"); MODULE_ALIAS("platform:mlx-platform");
> >
> Should this possibly be a dmi module alias ?

Do you mean just to change it to
MODULE_ALIAS("dmi:mlx-platform"); ?

Thank you very much for review.
Best regards,
Vadim.