Date:   Fri, 26 Nov 2021 13:39:09 +0100
From:   Henning Schild <henning.schild@siemens.com>
To:     <linux-kernel@vger.kernel.org>, <linux-leds@vger.kernel.org>,
        <platform-driver-x86@vger.kernel.org>,
        <linux-watchdog@vger.kernel.org>
Cc:     Srikanth Krishnakar <skrishnakar@gmail.com>,
        Jan Kiszka <jan.kiszka@siemens.com>,
        "Gerd Haeussler" <gerd.haeussler.ext@siemens.com>,
        Guenter Roeck <linux@roeck-us.net>,
        Wim Van Sebroeck <wim@linux-watchdog.org>,
        Mark Gross <mgross@linux.intel.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Pavel Machek <pavel@ucw.cz>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Enrico Weigelt <lkml@metux.net>
Subject: Re: [PATCH v3 1/4] platform/x86: simatic-ipc: add main driver for
 Siemens devices
Message-ID: <20211126133909.33fb1937@md1za8fc.ad001.siemens.net>
In-Reply-To: <20210329174928.18816-2-henning.schild@siemens.com>
References: <20210329174928.18816-1-henning.schild@siemens.com>
        <20210329174928.18816-2-henning.schild@siemens.com>
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Am Mon, 29 Mar 2021 19:49:25 +0200
schrieb Henning Schild <henning.schild@siemens.com>:

> This mainly implements detection of these devices and will allow
> secondary drivers to work on such machines.
> 
> The identification is DMI-based with a vendor specific way to tell
> them apart in a reliable way.
> 
> Drivers for LEDs and Watchdogs will follow to make use of that
> platform detection.
> 
> Signed-off-by: Henning Schild <henning.schild@siemens.com>
> ---
>  drivers/platform/x86/Kconfig                  |  12 ++
>  drivers/platform/x86/Makefile                 |   3 +
>  drivers/platform/x86/simatic-ipc.c            | 169
> ++++++++++++++++++ .../platform_data/x86/simatic-ipc-base.h      |
> 29 +++ include/linux/platform_data/x86/simatic-ipc.h |  72 ++++++++
>  5 files changed, 285 insertions(+)
>  create mode 100644 drivers/platform/x86/simatic-ipc.c
>  create mode 100644 include/linux/platform_data/x86/simatic-ipc-base.h
>  create mode 100644 include/linux/platform_data/x86/simatic-ipc.h
> 
> diff --git a/drivers/platform/x86/Kconfig
> b/drivers/platform/x86/Kconfig index 461ec61530eb..1eaa03d0d183 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -1289,6 +1289,18 @@ config INTEL_TELEMETRY
>  	  directly via debugfs files. Various tools may use
>  	  this interface for SoC state monitoring.
>  
> +config SIEMENS_SIMATIC_IPC
> +	tristate "Siemens Simatic IPC Class driver"
> +	depends on PCI
> +	help
> +	  This Simatic IPC class driver is the central of several
> drivers. It
> +	  is mainly used for system identification, after which
> drivers in other
> +	  classes will take care of driving specifics of those
> machines.
> +	  i.e. LEDs and watchdog.
> +
> +	  To compile this driver as a module, choose M here: the
> module
> +	  will be called simatic-ipc.
> +
>  endif # X86_PLATFORM_DEVICES
>  
>  config PMC_ATOM
> diff --git a/drivers/platform/x86/Makefile
> b/drivers/platform/x86/Makefile index 60d554073749..26cdebf2e701
> 100644 --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -138,3 +138,6 @@ obj-$(CONFIG_INTEL_TELEMETRY)		+=
> intel_telemetry_core.o \ intel_telemetry_pltdrv.o \
>  					   intel_telemetry_debugfs.o
>  obj-$(CONFIG_PMC_ATOM)			+= pmc_atom.o
> +
> +# Siemens Simatic Industrial PCs
> +obj-$(CONFIG_SIEMENS_SIMATIC_IPC)	+= simatic-ipc.o
> diff --git a/drivers/platform/x86/simatic-ipc.c
> b/drivers/platform/x86/simatic-ipc.c new file mode 100644
> index 000000000000..52e8596bc63d
> --- /dev/null
> +++ b/drivers/platform/x86/simatic-ipc.c
> @@ -0,0 +1,169 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Siemens SIMATIC IPC platform driver
> + *
> + * Copyright (c) Siemens AG, 2018-2021
> + *
> + * Authors:
> + *  Henning Schild <henning.schild@siemens.com>
> + *  Jan Kiszka <jan.kiszka@siemens.com>
> + *  Gerd Haeussler <gerd.haeussler.ext@siemens.com>
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/dmi.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/platform_data/x86/simatic-ipc.h>
> +#include <linux/platform_device.h>
> +
> +static struct platform_device *ipc_led_platform_device;
> +static struct platform_device *ipc_wdt_platform_device;
> +
> +static const struct dmi_system_id simatic_ipc_whitelist[] = {
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "SIEMENS AG"),
> +		},
> +	},
> +	{}
> +};
> +
> +static struct simatic_ipc_platform platform_data;
> +
> +static struct {
> +	u32 station_id;
> +	u8 led_mode;
> +	u8 wdt_mode;
> +} device_modes[] = {
> +	{SIMATIC_IPC_IPC127E, SIMATIC_IPC_DEVICE_127E,
> SIMATIC_IPC_DEVICE_NONE},
> +	{SIMATIC_IPC_IPC227D, SIMATIC_IPC_DEVICE_227D,
> SIMATIC_IPC_DEVICE_NONE},
> +	{SIMATIC_IPC_IPC227E, SIMATIC_IPC_DEVICE_427E,
> SIMATIC_IPC_DEVICE_227E},
> +	{SIMATIC_IPC_IPC277E, SIMATIC_IPC_DEVICE_NONE,
> SIMATIC_IPC_DEVICE_227E},
> +	{SIMATIC_IPC_IPC427D, SIMATIC_IPC_DEVICE_427E,
> SIMATIC_IPC_DEVICE_NONE},
> +	{SIMATIC_IPC_IPC427E, SIMATIC_IPC_DEVICE_427E,
> SIMATIC_IPC_DEVICE_427E},
> +	{SIMATIC_IPC_IPC477E, SIMATIC_IPC_DEVICE_NONE,
> SIMATIC_IPC_DEVICE_427E}, +};
> +
> +static int register_platform_devices(u32 station_id)
> +{
> +	u8 ledmode = SIMATIC_IPC_DEVICE_NONE;
> +	u8 wdtmode = SIMATIC_IPC_DEVICE_NONE;
> +	int i;
> +
> +	platform_data.devmode = SIMATIC_IPC_DEVICE_NONE;
> +
> +	for (i = 0; i < ARRAY_SIZE(device_modes); i++) {
> +		if (device_modes[i].station_id == station_id) {
> +			ledmode = device_modes[i].led_mode;
> +			wdtmode = device_modes[i].wdt_mode;
> +			break;
> +		}
> +	}
> +
> +	if (ledmode != SIMATIC_IPC_DEVICE_NONE) {
> +		platform_data.devmode = ledmode;
> +		ipc_led_platform_device =
> +			platform_device_register_data(NULL,
> +				KBUILD_MODNAME "_leds",
> PLATFORM_DEVID_NONE,
> +				&platform_data,
> +				sizeof(struct simatic_ipc_platform));
> +		if (IS_ERR(ipc_led_platform_device))
> +			return PTR_ERR(ipc_led_platform_device);
> +
> +		pr_debug("device=%s created\n",
> +			 ipc_led_platform_device->name);
> +	}
> +
> +	if (wdtmode != SIMATIC_IPC_DEVICE_NONE) {
> +		platform_data.devmode = wdtmode;
> +		ipc_wdt_platform_device =
> +			platform_device_register_data(NULL,
> +				KBUILD_MODNAME "_wdt",
> PLATFORM_DEVID_NONE,
> +				&platform_data,
> +				sizeof(struct simatic_ipc_platform));
> +		if (IS_ERR(ipc_wdt_platform_device))
> +			return PTR_ERR(ipc_wdt_platform_device);
> +
> +		pr_debug("device=%s created\n",
> +			 ipc_wdt_platform_device->name);
> +	}
> +
> +	if (ledmode == SIMATIC_IPC_DEVICE_NONE &&
> +	    wdtmode == SIMATIC_IPC_DEVICE_NONE) {
> +		pr_warn("unsupported IPC detected, station
> id=%08x\n",
> +			station_id);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +

extra newline, should be removed

> +/* FIXME: this should eventually be done with generic P2SB discovery
> code */ +/*
> + * Get membase address from PCI, used in leds and wdt modul. Here we
> read

/modul/module/

was pointed out already but forgotten about

Henning

> + * the bar0. The final address calculation is done in the
> appropriate modules
> + */
> +u32 simatic_ipc_get_membase0(unsigned int p2sb)
> +{
> +	struct pci_bus *bus;
> +	u32 bar0 = 0;
> +	/*
> +	 * The GPIO memory is in bar0 of the hidden P2SB device.
> +	 * Unhide the device to have a quick look at it, before we
> hide it
> +	 * again.
> +	 * Also grab the pci rescan lock so that device does not get
> discovered
> +	 * and remapped while it is visible.
> +	 * This code is inspired by drivers/mfd/lpc_ich.c
> +	 */
> +	bus = pci_find_bus(0, 0);
> +	pci_lock_rescan_remove();
> +	pci_bus_write_config_byte(bus, p2sb, 0xE1, 0x0);
> +	pci_bus_read_config_dword(bus, p2sb, PCI_BASE_ADDRESS_0,
> &bar0); +
> +	bar0 &= ~0xf;
> +	pci_bus_write_config_byte(bus, p2sb, 0xE1, 0x1);
> +	pci_unlock_rescan_remove();
> +
> +	return bar0;
> +}
> +EXPORT_SYMBOL(simatic_ipc_get_membase0);
> +
> +static int __init simatic_ipc_init_module(void)
> +{
> +	const struct dmi_system_id *match;
> +	u32 station_id;
> +	int err;
> +
> +	match = dmi_first_match(simatic_ipc_whitelist);
> +	if (!match)
> +		return 0;
> +
> +	err = dmi_walk(simatic_ipc_find_dmi_entry_helper,
> &station_id); +
> +	if (err || station_id == SIMATIC_IPC_INVALID_STATION_ID) {
> +		pr_warn("DMI entry %d not found\n",
> SIMATIC_IPC_DMI_ENTRY_OEM);
> +		return 0;
> +	}
> +
> +	return register_platform_devices(station_id);
> +}
> +
> +static void __exit simatic_ipc_exit_module(void)
> +{
> +	platform_device_unregister(ipc_led_platform_device);
> +	ipc_led_platform_device = NULL;
> +
> +	platform_device_unregister(ipc_wdt_platform_device);
> +	ipc_wdt_platform_device = NULL;
> +}
> +
> +module_init(simatic_ipc_init_module);
> +module_exit(simatic_ipc_exit_module);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Gerd Haeussler <gerd.haeussler.ext@siemens.com>");
> +MODULE_ALIAS("dmi:*:svnSIEMENSAG:*");
> diff --git a/include/linux/platform_data/x86/simatic-ipc-base.h
> b/include/linux/platform_data/x86/simatic-ipc-base.h new file mode
> 100644 index 000000000000..62d2bc774067
> --- /dev/null
> +++ b/include/linux/platform_data/x86/simatic-ipc-base.h
> @@ -0,0 +1,29 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Siemens SIMATIC IPC drivers
> + *
> + * Copyright (c) Siemens AG, 2018-2021
> + *
> + * Authors:
> + *  Henning Schild <henning.schild@siemens.com>
> + *  Gerd Haeussler <gerd.haeussler.ext@siemens.com>
> + */
> +
> +#ifndef __PLATFORM_DATA_X86_SIMATIC_IPC_BASE_H
> +#define __PLATFORM_DATA_X86_SIMATIC_IPC_BASE_H
> +
> +#include <linux/types.h>
> +
> +#define SIMATIC_IPC_DEVICE_NONE 0
> +#define SIMATIC_IPC_DEVICE_227D 1
> +#define SIMATIC_IPC_DEVICE_427E 2
> +#define SIMATIC_IPC_DEVICE_127E 3
> +#define SIMATIC_IPC_DEVICE_227E 4
> +
> +struct simatic_ipc_platform {
> +	u8	devmode;
> +};
> +
> +u32 simatic_ipc_get_membase0(unsigned int p2sb);
> +
> +#endif /* __PLATFORM_DATA_X86_SIMATIC_IPC_BASE_H */
> diff --git a/include/linux/platform_data/x86/simatic-ipc.h
> b/include/linux/platform_data/x86/simatic-ipc.h new file mode 100644
> index 000000000000..f3b76b39776b
> --- /dev/null
> +++ b/include/linux/platform_data/x86/simatic-ipc.h
> @@ -0,0 +1,72 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Siemens SIMATIC IPC drivers
> + *
> + * Copyright (c) Siemens AG, 2018-2021
> + *
> + * Authors:
> + *  Henning Schild <henning.schild@siemens.com>
> + *  Gerd Haeussler <gerd.haeussler.ext@siemens.com>
> + */
> +
> +#ifndef __PLATFORM_DATA_X86_SIMATIC_IPC_H
> +#define __PLATFORM_DATA_X86_SIMATIC_IPC_H
> +
> +#include <linux/dmi.h>
> +#include <linux/platform_data/x86/simatic-ipc-base.h>
> +
> +#define SIMATIC_IPC_DMI_ENTRY_OEM	129
> +/* binary type */
> +#define SIMATIC_IPC_DMI_TYPE		0xff
> +#define SIMATIC_IPC_DMI_GROUP		0x05
> +#define SIMATIC_IPC_DMI_ENTRY		0x02
> +#define SIMATIC_IPC_DMI_TID		0x02
> +
> +enum simatic_ipc_station_ids {
> +	SIMATIC_IPC_INVALID_STATION_ID = 0,
> +	SIMATIC_IPC_IPC227D = 0x00000501,
> +	SIMATIC_IPC_IPC427D = 0x00000701,
> +	SIMATIC_IPC_IPC227E = 0x00000901,
> +	SIMATIC_IPC_IPC277E = 0x00000902,
> +	SIMATIC_IPC_IPC427E = 0x00000A01,
> +	SIMATIC_IPC_IPC477E = 0x00000A02,
> +	SIMATIC_IPC_IPC127E = 0x00000D01,
> +};
> +
> +static inline u32 simatic_ipc_get_station_id(u8 *data, int max_len)
> +{
> +	struct {
> +		u8	type;		/* type (0xff =
> binary) */
> +		u8	len;		/* len of data entry */
> +		u8	group;
> +		u8	entry;
> +		u8	tid;
> +		__le32	station_id;	/* station id (LE)
> */
> +	} __packed * data_entry = (void *)data + sizeof(struct
> dmi_header); +
> +	while ((u8 *)data_entry < data + max_len) {
> +		if (data_entry->type == SIMATIC_IPC_DMI_TYPE &&
> +		    data_entry->len == sizeof(*data_entry) &&
> +		    data_entry->group == SIMATIC_IPC_DMI_GROUP &&
> +		    data_entry->entry == SIMATIC_IPC_DMI_ENTRY &&
> +		    data_entry->tid == SIMATIC_IPC_DMI_TID) {
> +			return le32_to_cpu(data_entry->station_id);
> +		}
> +		data_entry = (void *)((u8 *)(data_entry) +
> data_entry->len);
> +	}
> +
> +	return SIMATIC_IPC_INVALID_STATION_ID;
> +}
> +
> +static inline void
> +simatic_ipc_find_dmi_entry_helper(const struct dmi_header *dh, void
> *_data) +{
> +	u32 *id = _data;
> +
> +	if (dh->type != SIMATIC_IPC_DMI_ENTRY_OEM)
> +		return;
> +
> +	*id = simatic_ipc_get_station_id((u8 *)dh, dh->length);
> +}
> +
> +#endif /* __PLATFORM_DATA_X86_SIMATIC_IPC_H */