[v2,2/9] dm: soc: Introduce UCLASS_SOC for SOC ID and attribute matching

diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index 7b4e4d613088..e715dfd01712 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -1,5 +1,14 @@ 
 menu "SOC (System On Chip) specific Drivers"
 
+config SOC_DEVICE
+	bool "Enable SoC Device ID drivers using Driver Model"
+	help
+	  This allows drivers to be provided for SoCs to help in identifying
+	  the SoC in use and matching SoC attributes for selecting SoC
+	  specific data. This is useful for other device drivers that may
+	  need different parameters or quirks enabled depending on the
+	  specific device variant in use.
+
 source "drivers/soc/ti/Kconfig"
 
 endmenu
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index ce253b7aa886..1c09a8465670 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -3,3 +3,4 @@ 
 # Makefile for the U-Boot SOC specific device drivers.
 
 obj-$(CONFIG_SOC_TI) += ti/
+obj-$(CONFIG_SOC_DEVICE) += soc-uclass.o
diff --git a/drivers/soc/soc-uclass.c b/drivers/soc/soc-uclass.c
new file mode 100644
index 000000000000..c32d647864f2
--- /dev/null
+++ b/drivers/soc/soc-uclass.c
@@ -0,0 +1,102 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2020 - Texas Instruments Incorporated - http://www.ti.com/
+ *	Dave Gerlach <d-gerlach@ti.com>
+ */
+
+#include <common.h>
+#include <soc.h>
+#include <dm.h>
+#include <errno.h>
+#include <dm/lists.h>
+#include <dm/root.h>
+
+int soc_get(struct udevice **devp)
+{
+	return uclass_first_device_err(UCLASS_SOC, devp);
+}
+
+int soc_get_machine(struct udevice *dev, char *buf, int size)
+{
+	struct soc_ops *ops = soc_get_ops(dev);
+
+	if (!ops->get_machine)
+		return -ENOSYS;
+
+	return ops->get_machine(dev, buf, size);
+}
+
+int soc_get_family(struct udevice *dev, char *buf, int size)
+{
+	struct soc_ops *ops = soc_get_ops(dev);
+
+	if (!ops->get_family)
+		return -ENOSYS;
+
+	return ops->get_family(dev, buf, size);
+}
+
+int soc_get_revision(struct udevice *dev, char *buf, int size)
+{
+	struct soc_ops *ops = soc_get_ops(dev);
+
+	if (!ops->get_revision)
+		return -ENOSYS;
+
+	return ops->get_revision(dev, buf, size);
+}
+
+const struct soc_attr *
+soc_device_match(const struct soc_attr *matches)
+{
+	bool match;
+	struct udevice *soc;
+	char str[SOC_MAX_STR_SIZE];
+
+	if (!matches)
+		return NULL;
+
+	if (soc_get(&soc))
+		return NULL;
+
+	while (1) {
+		if (!(matches->machine || matches->family ||
+		      matches->revision))
+			break;
+
+		match = true;
+
+		if (matches->machine) {
+			if (!soc_get_machine(soc, str, SOC_MAX_STR_SIZE)) {
+				if (strcmp(matches->machine, str))
+					match = false;
+			}
+		}
+
+		if (matches->family) {
+			if (!soc_get_family(soc, str, SOC_MAX_STR_SIZE)) {
+				if (strcmp(matches->family, str))
+					match = false;
+			}
+		}
+
+		if (matches->revision) {
+			if (!soc_get_revision(soc, str, SOC_MAX_STR_SIZE)) {
+				if (strcmp(matches->revision, str))
+					match = false;
+			}
+		}
+
+		if (match)
+			return matches;
+
+		matches++;
+	}
+
+	return NULL;
+}
+
+UCLASS_DRIVER(soc) = {
+	.id		= UCLASS_SOC,
+	.name		= "soc",
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 7837d459f18c..690a8ed4df49 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -97,6 +97,7 @@  enum uclass_id {
 	UCLASS_SERIAL,		/* Serial UART */
 	UCLASS_SIMPLE_BUS,	/* Bus with child devices */
 	UCLASS_SMEM,		/* Shared memory interface */
+	UCLASS_SOC,		/* SOC Device */
 	UCLASS_SOUND,		/* Playing simple sounds */
 	UCLASS_SPI,		/* SPI bus */
 	UCLASS_SPI_FLASH,	/* SPI flash */
diff --git a/include/soc.h b/include/soc.h
new file mode 100644
index 000000000000..a55eb1b5724e
--- /dev/null
+++ b/include/soc.h
@@ -0,0 +1,145 @@ 
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * (C) Copyright 2020 - Texas Instruments Incorporated - http://www.ti.com/
+ *	Dave Gerlach <d-gerlach@ti.com>
+ */
+
+#ifndef __SOC_H
+#define __SOC_H
+
+#define SOC_MAX_STR_SIZE	128
+
+/**
+ * struct soc_attr - Contains SoC identify information to be used in
+ *		     SoC matching. An array of these structs
+ *		     representing different SoCs can be passed to
+ *		     soc_device_match and the struct matching the SoC
+ *		     in use will be returned.
+ *
+ * @family   - Name of SoC family that can include multiple related SoC
+ *	       variants. Example: am33
+ * @machine  - Name of a specific SoC. Example: am3352
+ * @revision - Name of a specific SoC revision. Example: SR1.1
+ * @data     - A pointer to user data for the SoC variant
+ */
+struct soc_attr {
+	const char *family;
+	const char *machine;
+	const char *revision;
+	const void *data;
+};
+
+struct soc_ops {
+	/**
+	 * get_machine() - Get machine name of an SOC
+	 *
+	 * @dev:	Device to check (UCLASS_SOC)
+	 * @buf:	Buffer to place string
+	 * @size:	Size of string space
+	 * @return 0 if OK, -ENOSPC if buffer is too small, other -ve on error
+	 */
+	int (*get_machine)(struct udevice *dev, char *buf, int size);
+
+	/**
+	 * get_revision() - Get revision name of a SOC
+	 *
+	 * @dev:	Device to check (UCLASS_SOC)
+	 * @buf:	Buffer to place string
+	 * @size:	Size of string space
+	 * @return 0 if OK, -ENOSPC if buffer is too small, other -ve on error
+	 */
+	int (*get_revision)(struct udevice *dev, char *buf, int size);
+
+	/**
+	 * get_family() - Get family name of an SOC
+	 *
+	 * @dev:	Device to check (UCLASS_SOC)
+	 * @buf:	Buffer to place string
+	 * @size:	Size of string space
+	 * @return 0 if OK, -ENOSPC if buffer is too small, other -ve on error
+	 */
+	int (*get_family)(struct udevice *dev, char *buf, int size);
+};
+
+#define soc_get_ops(dev)        ((struct soc_ops *)(dev)->driver->ops)
+
+#ifdef CONFIG_SOC_DEVICE
+/**
+ * soc_get() - Return the soc device for the soc in use.
+ * @devp: Pointer to structure to receive the soc device.
+ *
+ * Since there can only be at most one SOC instance, the API can supply a
+ * function that returns the unique device.
+ *
+ * Return: 0 if OK, -ve on error.
+ */
+int soc_get(struct udevice **devp);
+
+/**
+ * soc_get_machine() - Get machine name of an SOC
+ * @dev:	Device to check (UCLASS_SOC)
+ * @buf:	Buffer to place string
+ * @size:	Size of string space
+ *
+ * Return: 0 if OK, -ENOSPC if buffer is too small, other -ve on error
+ */
+int soc_get_machine(struct udevice *dev, char *buf, int size);
+
+/**
+ * soc_get_revision() - Get revision name of an SOC
+ * @dev:	Device to check (UCLASS_SOC)
+ * @buf:	Buffer to place string
+ * @size:	Size of string space
+ *
+ * Return: 0 if OK, -ENOSPC if buffer is too small, other -ve on error
+ */
+int soc_get_revision(struct udevice *dev, char *buf, int size);
+
+/**
+ * soc_get_family() - Get family name of an SOC
+ * @dev:	Device to check (UCLASS_SOC)
+ * @buf:	Buffer to place string
+ * @size:	Size of string space
+ *
+ * Return: 0 if OK, -ENOSPC if buffer is too small, other -ve on error
+ */
+int soc_get_family(struct udevice *dev, char *buf, int size);
+
+/**
+ * soc_device_match() - Return match from an array of soc_attr
+ * @matches:	Array with any combination of family, revision or machine set
+ *
+ * Return: Pointer to struct from matches array with set attributes matching
+ *	   those provided by the soc device, or NULL if no match found.
+ */
+const struct soc_attr *
+soc_device_match(const struct soc_attr *matches);
+
+#else
+static inline int soc_get(struct udevice **devp)
+{
+	return -ENOSYS;
+}
+
+static inline int soc_get_machine(struct udevice *dev, char *buf, int size)
+{
+	return -ENOSYS;
+}
+
+static inline int soc_get_revision(struct udevice *dev, char *buf, int size)
+{
+	return -ENOSYS;
+}
+
+static inline int soc_get_family(struct udevice *dev, char *buf, int size)
+{
+	return -ENOSYS;
+}
+
+static inline const struct soc_attr *
+soc_device_match(const struct soc_attr *matches)
+{
+	return NULL;
+}
+#endif
+#endif /* _SOC_H */