[PATCH v2 1/4] platform/x86: simatic-ipc: add main driver for Siemens devices

Henning Schild
2021-03-15T10:03:50Z

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 | 168 ++++++++++++++++++
.../platform_data/x86/simatic-ipc-base.h | 29 +++
include/linux/platform_data/x86/simatic-ipc.h | 66 +++++++
5 files changed, 278 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 ad4e630e73e2..44f8e82e1fd9 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -1284,6 +1284,18 @@ 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..7c32c12ad32d
--- /dev/null
+++ b/drivers/platform/x86/simatic-ipc.c
@@ -0,0 +1,168 @@
+// 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;
+}
+
+/*
+ * Get membase address from PCI, used in leds and wdt modul. Here we read
+ * 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 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", 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..3af84a84f103
--- /dev/null
+++ b/include/linux/platform_data/x86/simatic-ipc.h
@@ -0,0 +1,66 @@
+/* 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 DMI_ENTRY_OEM 129
+
+enum 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)
+{
+ u32 station_id = SIMATIC_IPC_INVALID_STATION_ID;
+ int i;
+ struct {
+ u8 type; /* type (0xff = binary) */
+ u8 len; /* len of data entry */
+ u8 reserved[3];
+ u32 station_id; /* station id (LE) */
+ } __packed
+ *data_entry = (void *)data + sizeof(struct dmi_header);
+
+ /* find 4th entry in OEM data */
+ for (i = 0; i < 3; i++)
+ data_entry = (void *)((u8 *)(data_entry) + data_entry->len);
+
+ /* decode station id */
+ if (data_entry && (u8 *)data_entry < data + max_len &&
+ data_entry->type == 0xff && data_entry->len == 9)
+ station_id = le32_to_cpu(data_entry->station_id);
+
+ return station_id;
+}
+
+static inline void
+simatic_ipc_find_dmi_entry_helper(const struct dmi_header *dh, void *_data)
+{
+ u32 *id = _data;
+
+ if (dh->type != DMI_ENTRY_OEM)
+ return;
+
+ *id = simatic_ipc_get_station_id((u8 *)dh, dh->length);
+}
+
+#endif /* __PLATFORM_DATA_X86_SIMATIC_IPC_H */
--
2.26.2