MIPS: PS2: SCMD: Read system machine name command

Signed-off-by: Fredrik Noring <noring@nocrew.org>
frno7 · May 13, 2019 · e16b1ae · e16b1ae
1 parent e6c6749
commit e16b1ae
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diff --git a/arch/mips/include/asm/mach-ps2/scmd.h b/arch/mips/include/asm/mach-ps2/scmd.h
@@ -26,4 +26,15 @@ int scmd(u8 cmd,
 /* Send power off system command. */
 int scmd_power_off(void);
 
+struct scmd_machine_name {
+	char name[17];	/* NUL terminated string, for example "SCPH-50004" */
+};
+
+/*
+ * Reads the machine name. Returns the empty string on failure, most notably
+ * for models SCPH-10000 and SCPH-15000. Late SCPH-10000 and all SCPH-15000
+ * have the name in rom0:OSDSYS instead.
+ */
+struct scmd_machine_name scmd_read_machine_name(void);
+
 #endif /* __ASM_PS2_SCMD_H */
diff --git a/arch/mips/ps2/scmd.c b/arch/mips/ps2/scmd.c
@@ -117,6 +117,11 @@ int scmd(u8 cmd,
 }
 EXPORT_SYMBOL_GPL(scmd);
 
+static int scmd_send_byte(u8 cmd, u8 send_byte, void *recv, size_t recv_size)
+{
+	return scmd(cmd, &send_byte, sizeof(send_byte), recv, recv_size);
+}
+
 int scmd_power_off(void)
 {
 	u8 status;
@@ -138,6 +143,49 @@ int scmd_power_off(void)
 }
 EXPORT_SYMBOL_GPL(scmd_power_off);
 
+struct scmd_machine_name scmd_read_machine_name(void)
+{
+	struct scmd_machine_name machine = { .name = "" };
+	struct __attribute__ ((packed)) {
+		u8 status;
+		char name[8];
+	} buffer0, buffer8;
+	int err;
+
+	BUILD_BUG_ON(sizeof(buffer0) != 9 ||
+		     sizeof(buffer8) != 9);
+
+	/* The machine name comes in two halves that need to be combined. */
+
+	err = scmd_send_byte(0x17, 0, &buffer0, sizeof(buffer0));
+	if (err < 0) {
+		pr_debug("%s: Read failed with %d at 0\n", __func__, err);
+		goto out_err;
+	}
+
+	err = scmd_send_byte(0x17, 8, &buffer8, sizeof(buffer8));
+	if (err < 0) {
+		pr_debug("%s: Read failed with %d at 8\n", __func__, err);
+		goto out_err;
+	}
+
+	if (buffer0.status != 0 ||
+	    buffer8.status != 0) {
+		pr_debug("%s: Invalid results with statuses 0x%x and 0x%x\n",
+			__func__, buffer0.status, buffer8.status);
+		goto out_err;
+	}
+
+	BUILD_BUG_ON(sizeof(machine.name) < 17);
+	memcpy(&machine.name[0], buffer0.name, 8);
+	memcpy(&machine.name[8], buffer8.name, 8);
+	machine.name[16] = '\0';
+
+out_err:
+	return machine;
+}
+EXPORT_SYMBOL_GPL(scmd_read_machine_name);
+
 MODULE_DESCRIPTION("PlayStation 2 system command driver");
 MODULE_AUTHOR("Fredrik Noring");
 MODULE_LICENSE("GPL");