nvmem: sec-qfprom: Add Qualcomm secure QFPROM support

For some of the Qualcomm SoC's, it is possible that
some of the fuse regions or entire qfprom region is
protected from non-secure access. In such situations,
the OS will have to use secure calls to read the region.
With that motivation, add secure qfprom driver.

Signed-off-by: Komal Bajaj <quic_kbajaj@quicinc.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230823132744.350618-18-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 7ab12fc..5bc9c48 100644 (file)
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -226,6 +226,19 @@ config NVMEM_QCOM_QFPROM
          This driver can also be built as a module. If so, the module
          will be called nvmem_qfprom.
 
+config NVMEM_QCOM_SEC_QFPROM
+        tristate "QCOM SECURE QFPROM Support"
+        depends on ARCH_QCOM || COMPILE_TEST
+        depends on HAS_IOMEM
+        depends on OF
+        select QCOM_SCM
+        help
+          Say y here to enable secure QFPROM support. The secure QFPROM provides access
+          functions for QFPROM data to rest of the drivers via nvmem interface.
+
+          This driver can also be built as a module. If so, the module will be called
+          nvmem_sec_qfprom.
+
 config NVMEM_RAVE_SP_EEPROM
        tristate "Rave SP EEPROM Support"
        depends on RAVE_SP_CORE

diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index e0e67a9..423baf0 100644 (file)
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -46,6 +46,8 @@ obj-$(CONFIG_NVMEM_NINTENDO_OTP)      += nvmem-nintendo-otp.o
 nvmem-nintendo-otp-y                   := nintendo-otp.o
 obj-$(CONFIG_NVMEM_QCOM_QFPROM)                += nvmem_qfprom.o
 nvmem_qfprom-y                         := qfprom.o
+obj-$(CONFIG_NVMEM_QCOM_SEC_QFPROM)    += nvmem_sec_qfprom.o
+nvmem_sec_qfprom-y                     := sec-qfprom.o
 obj-$(CONFIG_NVMEM_RAVE_SP_EEPROM)     += nvmem-rave-sp-eeprom.o
 nvmem-rave-sp-eeprom-y                 := rave-sp-eeprom.o
 obj-$(CONFIG_NVMEM_RMEM)               += nvmem-rmem.o

diff --git a/drivers/nvmem/sec-qfprom.c b/drivers/nvmem/sec-qfprom.c
new file mode 100644 (file)
index 0000000..e48c2dc
--- /dev/null
+++ b/drivers/nvmem/sec-qfprom.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/firmware/qcom/qcom_scm.h>
+#include <linux/mod_devicetable.h>
+#include <linux/nvmem-provider.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+/**
+ * struct sec_qfprom - structure holding secure qfprom attributes
+ *
+ * @base: starting physical address for secure qfprom corrected address space.
+ * @dev: qfprom device structure.
+ */
+struct sec_qfprom {
+       phys_addr_t base;
+       struct device *dev;
+};
+
+static int sec_qfprom_reg_read(void *context, unsigned int reg, void *_val, size_t bytes)
+{
+       struct sec_qfprom *priv = context;
+       unsigned int i;
+       u8 *val = _val;
+       u32 read_val;
+       u8 *tmp;
+
+       for (i = 0; i < bytes; i++, reg++) {
+               if (i == 0 || reg % 4 == 0) {
+                       if (qcom_scm_io_readl(priv->base + (reg & ~3), &read_val)) {
+                               dev_err(priv->dev, "Couldn't access fuse register\n");
+                               return -EINVAL;
+                       }
+                       tmp = (u8 *)&read_val;
+               }
+
+               val[i] = tmp[reg & 3];
+       }
+
+       return 0;
+}
+
+static int sec_qfprom_probe(struct platform_device *pdev)
+{
+       struct nvmem_config econfig = {
+               .name = "sec-qfprom",
+               .stride = 1,
+               .word_size = 1,
+               .id = NVMEM_DEVID_AUTO,
+               .reg_read = sec_qfprom_reg_read,
+       };
+       struct device *dev = &pdev->dev;
+       struct nvmem_device *nvmem;
+       struct sec_qfprom *priv;
+       struct resource *res;
+
+       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res)
+               return -EINVAL;
+
+       priv->base = res->start;
+
+       econfig.size = resource_size(res);
+       econfig.dev = dev;
+       econfig.priv = priv;
+
+       priv->dev = dev;
+
+       nvmem = devm_nvmem_register(dev, &econfig);
+
+       return PTR_ERR_OR_ZERO(nvmem);
+}
+
+static const struct of_device_id sec_qfprom_of_match[] = {
+       { .compatible = "qcom,sec-qfprom" },
+       {/* sentinel */},
+};
+MODULE_DEVICE_TABLE(of, sec_qfprom_of_match);
+
+static struct platform_driver qfprom_driver = {
+       .probe = sec_qfprom_probe,
+       .driver = {
+               .name = "qcom_sec_qfprom",
+               .of_match_table = sec_qfprom_of_match,
+       },
+};
+module_platform_driver(qfprom_driver);
+MODULE_DESCRIPTION("Qualcomm Secure QFPROM driver");
+MODULE_LICENSE("GPL");