hdata/i2c: Add whitelisting for Host I2C devices

Many of the devices that we get information about through HDAT are for
use by firmware rather than the host operating system. This patch adds
a boolean flag to hdat_i2c_info structure that indicates whether devices
with a given purpose should be reserved for use inside of OPAL (or some
other firmware component, such as the OCC).

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>

hdata/i2c.c

@@ -129,30 +129,31 @@ static struct hdat_i2c_type hdat_i2c_devs[] = {
 	{ 0x13, "i2c", "nxp,lpc11u35" },
 };
 
-struct hdat_i2c_label {
+struct hdat_i2c_info {
 	uint32_t id;
+	bool whitelist; /* true if the host may use the device */
 	const char *label;
 };
 
-static struct hdat_i2c_label hdat_i2c_labels[] = {
-	{ 0x1, "led-controller" },
-	{ 0x2, "pci-hotplug-pgood" },
-	{ 0x3, "pci-hotplug-control" },
-	{ 0x4, "tpm" },
-	{ 0x5, "module-vpd" },
-	{ 0x6, "dimm SPD" },
-	{ 0x7, "proc-vpd" },
-	{ 0x8, "sbe-eeprom" },
-	{ 0x9, "planar-vpd" },
-	{ 0xa, "opencapi-topology" },
-	{ 0xb, "opencapi-micro-reset" },
-	{ 0xc, "nvlink-cable" },
-	{ 0xd, "secure-window-open" },
-	{ 0xe, "physical-presence" },
-	{ 0xf, "mex-fpga" },
-	{ 0x10, "thermal-sensor" },
-	{ 0x11, "host-i2c-enable" },
-	{ 0x12, "gpu-config" },
+static struct hdat_i2c_info hdat_i2c_extra_info[] = {
+	{ 0x1,  false, "led-controller" },
+	{ 0x2,  false, "pci-hotplug-pgood" },
+	{ 0x3,  false, "pci-hotplug-control" },
+	{ 0x4,  true,  "tpm" },
+	{ 0x5,  true,  "module-vpd" },
+	{ 0x6,  true,  "dimm-spd" },
+	{ 0x7,  true,  "proc-vpd" },
+	{ 0x8,  false, "sbe-eeprom"},
+	{ 0x9,  true,  "planar-vpd" },
+	{ 0xa,  false, "opencapi-topology" },
+	{ 0xb,  false, "opencapi-micro-reset" },
+	{ 0xc,  false, "nvlink-cable" },
+	{ 0xd,  false, "secure-window-open" },
+	{ 0xe,  false, "physical-presence" },
+	{ 0xf,  false, "mex-fpga" },
+	{ 0x10, false, "thermal-sensor" },
+	{ 0x11, false, "host-i2c-enable" },
+	{ 0x12, false, "gpu-config" },
 };
 
 /*
@@ -171,15 +172,17 @@ static struct hdat_i2c_type *map_type(uint32_t type)
 	return NULL;
 }
 
-static const char *map_label(uint32_t type)
+static struct hdat_i2c_info *get_info(uint32_t type)
 {
+	static struct hdat_i2c_info no_info =
+		{ .id = 0x0, .whitelist = false, .label = "" };
 	int i;
 
-	for (i = 0; i < ARRAY_SIZE(hdat_i2c_labels); i++)
-		if (hdat_i2c_labels[i].id == type)
-			return hdat_i2c_labels[i].label;
+	for (i = 0; i < ARRAY_SIZE(hdat_i2c_extra_info); i++)
+		if (hdat_i2c_extra_info[i].id == type)
+			return &hdat_i2c_extra_info[i];
 
-	return NULL;
+	return &no_info;
 }
 
 static bool is_zeros(const void *p, size_t size)
@@ -204,8 +207,9 @@ int parse_i2c_devs(const struct HDIF_common_hdr *hdr, int idata_index,
 {
 	struct dt_node *i2cm, *bus, *node;
 	const struct hdat_i2c_type *type;
+	const struct hdat_i2c_info *info;
 	const struct i2c_dev *dev;
-	const char *label, *name, *compat;
+	const char *name, *compat;
 	const struct host_i2c_hdr *ahdr;
 	uint32_t dev_addr;
 	uint32_t version;
@@ -284,7 +288,7 @@ int parse_i2c_devs(const struct HDIF_common_hdr *hdr, int idata_index,
 
 		purpose = be32_to_cpu(dev->purpose);
 		type = map_type(dev->type);
-		label = map_label(purpose);
+		info = get_info(purpose);
 
 		/* HACK: Hostboot doesn't export the correct type information
 		 * for the DIMM SPD EEPROMs. This is a problem because SPD
@@ -316,11 +320,11 @@ int parse_i2c_devs(const struct HDIF_common_hdr *hdr, int idata_index,
 		if (!type || dev->type == 0xFF)
 			prlog(PR_WARNING, "HDAT I2C: found e%dp%d - %s@%x dp:%02x (%#x:%s)\n",
 			      dev->i2cm_engine, dev->i2cm_port, name, dev_addr,
-			      dev->dev_port, purpose, label);
+			      dev->dev_port, purpose, info->label);
 		else
 			prlog(PR_DEBUG, "HDAT I2C: found e%dp%d - %s@%x dp:%02x (%#x:%s)\n",
 			      dev->i2cm_engine, dev->i2cm_port, name, dev_addr,
-			      dev->dev_port, purpose, label);
+			      dev->dev_port, purpose, info->label);
 
 		/*
 		 * Multi-port device require special handling since we need to
@@ -340,8 +344,10 @@ int parse_i2c_devs(const struct HDIF_common_hdr *hdr, int idata_index,
 			be32_to_cpu(dev->i2c_link));
 		if (compat)
 			dt_add_property_string(node, "compatible", compat);
-		if (label)
-			dt_add_property_string(node, "label", label);
+		if (info->label)
+			dt_add_property_string(node, "label", info->label);
+		if (!info->whitelist)
+			dt_add_property_string(node, "status", "reserved");
 
 		/*
 		 * Set a default timeout of 2s on the ports with a TPM. This is