Resguardo inicial

linux-7.2.3/drivers/soc/vt8500/Kconfig

@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+if ARCH_VT8500 || COMPILE_TEST
+
+menu "VIA/WonderMedia SoC drivers"
+
+config WMT_SOCINFO
+	bool "VIA/WonderMedia SoC Information driver"
+	default ARCH_VT8500
+	select SOC_BUS
+	help
+	  Say yes to support decoding of VIA/WonderMedia system configuration
+	  register information. This currently includes just the chip ID register
+	  which helps identify the exact hardware revision of the SoC the kernel
+	  is running on (to know if any revision-specific quirks are required)
+
+endmenu
+
+endif

linux-7.2.3/drivers/soc/vt8500/Makefile

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+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_WMT_SOCINFO)	+= wmt-socinfo.o

linux-7.2.3/drivers/soc/vt8500/wmt-socinfo.c

@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2025 Alexey Charkov <alchark@gmail.com>
+ * Based on aspeed-socinfo.c
+ */
+
+#include <linux/dev_printk.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/sys_soc.h>
+
+static const struct {
+	const char *name;
+	const u32 id;
+} chip_id_table[] = {
+	/* VIA */
+	{ "VT8420", 0x3300 },
+	{ "VT8430", 0x3357 },
+	{ "VT8500", 0x3400 },
+
+	/* WonderMedia */
+	{ "WM8425", 0x3429 },
+	{ "WM8435", 0x3437 },
+	{ "WM8440", 0x3451 },
+	{ "WM8505", 0x3426 },
+	{ "WM8650", 0x3465 },
+	{ "WM8750", 0x3445 },
+	{ "WM8850", 0x3481 },
+	{ "WM8880", 0x3498 },
+};
+
+static const char *sccid_to_name(u32 sccid)
+{
+	u32 id = sccid >> 16;
+	unsigned int i;
+
+	for (i = 0 ; i < ARRAY_SIZE(chip_id_table) ; ++i) {
+		if (chip_id_table[i].id == id)
+			return chip_id_table[i].name;
+	}
+
+	return "Unknown";
+}
+
+static int wmt_socinfo_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct soc_device_attribute *attrs;
+	struct soc_device *soc_dev;
+	char letter, digit;
+	void __iomem *reg;
+	u32 sccid;
+
+	reg = devm_of_iomap(&pdev->dev, np, 0, NULL);
+	if (IS_ERR(reg))
+		return PTR_ERR(reg);
+
+	sccid = readl(reg);
+
+	attrs = devm_kzalloc(&pdev->dev, sizeof(*attrs), GFP_KERNEL);
+	if (!attrs)
+		return -ENOMEM;
+
+	/*
+	 * Machine: VIA APC Rock
+	 * Family: WM8850
+	 * Revision: A2
+	 * SoC ID: raw silicon revision id (34810103 in hexadecimal)
+	 */
+
+	attrs->family = sccid_to_name(sccid);
+
+	letter = (sccid >> 8) & 0xf;
+	letter = (letter - 1) + 'A';
+	digit = sccid & 0xff;
+	digit = (digit - 1) + '0';
+	attrs->revision = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+					 "%c%c", letter, digit);
+
+	attrs->soc_id = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%08x", sccid);
+
+	if (!attrs->revision || !attrs->soc_id)
+		return -ENOMEM;
+
+	soc_dev = soc_device_register(attrs);
+	if (IS_ERR(soc_dev))
+		return PTR_ERR(soc_dev);
+
+	dev_info(&pdev->dev,
+		 "VIA/WonderMedia %s rev %s (%s)\n",
+		 attrs->family,
+		 attrs->revision,
+		 attrs->soc_id);
+
+	platform_set_drvdata(pdev, soc_dev);
+	return 0;
+}
+
+static void wmt_socinfo_remove(struct platform_device *pdev)
+{
+	struct soc_device *soc_dev = platform_get_drvdata(pdev);
+
+	soc_device_unregister(soc_dev);
+}
+
+static const struct of_device_id wmt_socinfo_ids[] = {
+	{ .compatible = "via,vt8500-scc-id" },
+	{ /* Sentinel */ },
+};
+
+static struct platform_driver wmt_socinfo = {
+	.probe = wmt_socinfo_probe,
+	.remove = wmt_socinfo_remove,
+	.driver = {
+		.name = "wmt-socinfo",
+		.of_match_table = wmt_socinfo_ids,
+	},
+};
+module_platform_driver(wmt_socinfo);
+
+MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
+MODULE_DESCRIPTION("VIA/WonderMedia socinfo driver");
+MODULE_LICENSE("GPL");