platform/x86: simatic-ipc: add main driver for Siemens devices

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.

There is also some code to allow secondary drivers to find GPIO memory,
that needs to be in place because the pinctrl drivers do not come up.

Signed-off-by: Henning Schild <henning.schild@siemens.com>
Link: https://lore.kernel.org/r/20211213120502.20661-2-henning.schild@siemens.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

2 files changed, 101 insertions, 0 deletions

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 */