soc: qcom: add secure processor subsystem (spss) utils driver

The spss-util driver provides utilities required for the SPSS.
It provides the fuse state for key selection.
It provides the SPSS HW version.

Change-Id: I70c37d64db351db86e3d1d5dddb810257c68d72f
Signed-off-by: Amir Samuelov <amirs@codeaurora.org>

3 files changed, 306 insertions, 0 deletions

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index f884f829b51c..9c27344165be 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -127,6 +127,17 @@ config MSM_SPCOM
 	  spcom provides clients/server API, although currently only one client
 	  or server is allowed per logical channel.
 
+config MSM_SPSS_UTILS
+	depends on MSM_PIL
+	bool "Secure Processor Utilities"
+	help
+	  spss-utils driver selects Secure Processor firmware file name.
+	  The firmware file name for test or production is selected based
+	  on a test fuse.
+	  Different file name is used for differnt SPSS HW versions,
+	  because the SPSS firmware size is too small to support multiple
+	  HW versions.
+
 config MSM_SMEM_LOGGING
 	depends on MSM_SMEM
 	bool "MSM Shared Memory Logger"
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index fb8437d7a7c3..d9134a558be6 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_MSM_IPC_ROUTER_HSIC_XPRT)	+=	ipc_router_hsic_xprt.o
 obj-$(CONFIG_MSM_IPC_ROUTER_MHI_XPRT)	+=	ipc_router_mhi_xprt.o
 obj-$(CONFIG_MSM_IPC_ROUTER_GLINK_XPRT)	+=	ipc_router_glink_xprt.o
 obj-$(CONFIG_MSM_SPCOM) += spcom.o
+obj-$(CONFIG_MSM_SPSS_UTILS) += spss_utils.o
 obj-y			+=	qdsp6v2/
 obj-$(CONFIG_MSM_SYSTEM_HEALTH_MONITOR)	+=	system_health_monitor_v01.o
 obj-$(CONFIG_MSM_SYSTEM_HEALTH_MONITOR)	+=	system_health_monitor.o
diff --git a/drivers/soc/qcom/spss_utils.c b/drivers/soc/qcom/spss_utils.c
new file mode 100644
index 000000000000..9f799dfd9003
--- /dev/null
+++ b/drivers/soc/qcom/spss_utils.c
@@ -0,0 +1,294 @@
+/*
+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * Secure-Processor-SubSystem (SPSS) utilities.
+ *
+ * This driver provides utilities for the Secure Processor (SP).
+ *
+ * The SP daemon needs to load different SPSS images based on:
+ *
+ * 1. Test/Production key used to sign the SPSS image (read fuse).
+ * 2. SPSS HW version (selected via Device Tree).
+ *
+ */
+
+#define pr_fmt(fmt)	"spss_utils [%s]: " fmt, __func__
+
+#include <linux/kernel.h>	/* min() */
+#include <linux/module.h>	/* MODULE_LICENSE */
+#include <linux/device.h>	/* class_create() */
+#include <linux/slab.h>	/* kzalloc() */
+#include <linux/fs.h>		/* file_operations */
+#include <linux/cdev.h>		/* cdev_add() */
+#include <linux/errno.h>	/* EINVAL, ETIMEDOUT */
+#include <linux/printk.h>	/* pr_err() */
+#include <linux/bitops.h>	/* BIT(x) */
+#include <linux/platform_device.h> /* platform_driver_register() */
+#include <linux/of.h>		/* of_property_count_strings() */
+#include <linux/io.h>		/* ioremap_nocache() */
+
+#include <soc/qcom/subsystem_restart.h>
+
+/* driver name */
+#define DEVICE_NAME	"spss-utils"
+
+static bool is_test_fuse_set;
+static const char *test_firmware_name;
+static const char *prod_firmware_name;
+static const char *firmware_name;
+static struct device *spss_dev;
+
+/*==========================================================================*/
+/*		Device Sysfs */
+/*==========================================================================*/
+
+static ssize_t firmware_name_show(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	int ret;
+
+	if (!dev || !attr || !buf) {
+		pr_err("invalid param.\n");
+		return -EINVAL;
+	}
+
+	if (firmware_name == NULL)
+		ret = snprintf(buf, PAGE_SIZE, "%s\n", "unknown");
+	else
+		ret = snprintf(buf, PAGE_SIZE, "%s\n", firmware_name);
+
+	return ret;
+}
+
+static ssize_t firmware_name_store(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t size)
+{
+	pr_err("set firmware name is not allowed.\n");
+
+	return -EINVAL;
+}
+
+static DEVICE_ATTR(firmware_name, 0444,
+		firmware_name_show, firmware_name_store);
+
+static ssize_t test_fuse_state_show(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	int ret;
+
+	if (!dev || !attr || !buf) {
+		pr_err("invalid param.\n");
+		return -EINVAL;
+	}
+
+	if (is_test_fuse_set)
+		ret = snprintf(buf, PAGE_SIZE, "%s\n", "test");
+	else
+		ret = snprintf(buf, PAGE_SIZE, "%s\n", "prod");
+
+	return ret;
+}
+
+static ssize_t test_fuse_state_store(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t size)
+{
+	pr_err("set test fuse state is not allowed.\n");
+
+	return -EINVAL;
+}
+
+static DEVICE_ATTR(test_fuse_state, 0444,
+		test_fuse_state_show, test_fuse_state_store);
+
+static int spss_create_sysfs(struct device *dev)
+{
+	int ret;
+
+	ret = device_create_file(dev, &dev_attr_firmware_name);
+	if (ret < 0) {
+		pr_err("failed to create sysfs file for firmware_name.\n");
+		return ret;
+	}
+
+	ret = device_create_file(dev, &dev_attr_test_fuse_state);
+	if (ret < 0) {
+		pr_err("failed to create sysfs file for test_fuse_state.\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+/*==========================================================================*/
+/*		Device Tree */
+/*==========================================================================*/
+
+/**
+ * spss_parse_dt() - Parse Device Tree info.
+ */
+static int spss_parse_dt(struct device_node *node)
+{
+	int ret;
+	u32 spss_fuse_addr = 0;
+	u32 spss_fuse_bit = 0;
+	u32 spss_fuse_mask = 0;
+	void __iomem *spss_fuse_reg = NULL;
+	u32 val = 0;
+
+	ret = of_property_read_string(node, "qcom,spss-test-firmware-name",
+		&test_firmware_name);
+	if (ret < 0) {
+		pr_err("can't get test fw name.\n");
+		return -EFAULT;
+	}
+
+	ret = of_property_read_string(node, "qcom,spss-prod-firmware-name",
+		&prod_firmware_name);
+	if (ret < 0) {
+		pr_err("can't get prod fw name.\n");
+		return -EFAULT;
+	}
+
+	ret = of_property_read_u32(node, "qcom,spss-fuse-addr",
+		&spss_fuse_addr);
+	if (ret < 0) {
+		pr_err("can't get fuse addr.\n");
+		return -EFAULT;
+	}
+
+	ret = of_property_read_u32(node, "qcom,spss-fuse-bit",
+		&spss_fuse_bit);
+	if (ret < 0) {
+		pr_err("can't get fuse bit.\n");
+		return -EFAULT;
+	}
+
+	spss_fuse_mask = BIT(spss_fuse_bit);
+
+	pr_debug("spss_fuse_addr [0x%x] , spss_fuse_bit [%d] .\n",
+		(int) spss_fuse_addr, (int) spss_fuse_bit);
+
+	spss_fuse_reg = ioremap_nocache(spss_fuse_addr, sizeof(u32));
+
+	if (!spss_fuse_reg) {
+		pr_err("can't map fuse addr.\n");
+		return -EFAULT;
+	}
+
+	val = readl_relaxed(spss_fuse_reg);
+
+	pr_debug("spss fuse register value [0x%x].\n", (int) val);
+
+	if (val & spss_fuse_mask)
+		is_test_fuse_set = true;
+
+	iounmap(spss_fuse_reg);
+
+	return 0;
+}
+
+/**
+ * spss_probe() - initialization sequence
+ */
+static int spss_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct device_node *np = NULL;
+	struct device *dev = NULL;
+
+	if (!pdev) {
+		pr_err("invalid pdev.\n");
+		return -ENODEV;
+	}
+
+	np = pdev->dev.of_node;
+	if (!np) {
+		pr_err("invalid DT node.\n");
+		return -EINVAL;
+	}
+
+	dev = &pdev->dev;
+	spss_dev = dev;
+
+	if (dev == NULL) {
+		pr_err("invalid dev.\n");
+		return -EINVAL;
+	}
+
+	platform_set_drvdata(pdev, dev);
+
+	ret = spss_parse_dt(np);
+	if (ret < 0) {
+		pr_err("fail to parse device tree.\n");
+		return -EFAULT;
+	}
+
+	if (is_test_fuse_set)
+		firmware_name = test_firmware_name;
+	else
+		firmware_name = prod_firmware_name;
+
+	ret = subsystem_set_fwname("spss", firmware_name);
+	if (ret < 0) {
+		pr_err("fail to set fw name.\n");
+		return -EFAULT;
+	}
+
+	spss_create_sysfs(dev);
+
+	pr_info("Initialization completed ok, firmware_name [%s].\n",
+		firmware_name);
+
+	return 0;
+}
+
+static const struct of_device_id spss_match_table[] = {
+	{ .compatible = "qcom,spss-utils", },
+	{ },
+};
+
+static struct platform_driver spss_driver = {
+	.probe = spss_probe,
+	.driver = {
+		.name = DEVICE_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(spss_match_table),
+	},
+};
+
+/*==========================================================================*/
+/*		Driver Init/Exit					*/
+/*==========================================================================*/
+static int __init spss_init(void)
+{
+	int ret = 0;
+
+	pr_info("spss-utils driver Ver 1.0 12-Sep-2016.\n");
+
+	ret = platform_driver_register(&spss_driver);
+	if (ret)
+		pr_err("register platform driver failed, ret [%d]\n", ret);
+
+	return 0;
+}
+late_initcall(spss_init); /* start after PIL driver */
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Secure Processor Utilities");