[PATCH 3/3] nvmem: zynqmp: Added zynqmp nvmem firmware driver

Nava kishore Manne
2018-10-19T08:37:58Z

This patch adds zynqmp nvmem firmware driver to access the
SoC revision information from the hardware register.

Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
---
Changes for v1:
-None

Changes for RFC-V3:
-Changed nvmem_register() to devm_nvmem_register()
and pr_debug() to dev_dbg() as suggested by srinivas.

Changes for RFC-V2:
-None.

drivers/nvmem/Kconfig | 15 ++++----
drivers/nvmem/Makefile | 5 +--
drivers/nvmem/zynqmp_nvmem.c | 86 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 96 insertions(+), 10 deletions(-)
create mode 100644 drivers/nvmem/zynqmp_nvmem.c

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 0a7a470e..2edb142 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -181,15 +181,14 @@ config RAVE_SP_EEPROM
help
Say y here to enable Rave SP EEPROM support.

-config SC27XX_EFUSE
- tristate "Spreadtrum SC27XX eFuse Support"
- depends on MFD_SC27XX_PMIC || COMPILE_TEST
- depends on HAS_IOMEM
+config NVMEM_ZYNQMP
+ bool "Xilinx ZYNQMP SoC nvmem firmware support"
+ depends on ARCH_ZYNQMP
help
- This is a simple driver to dump specified values of Spreadtrum
- SC27XX PMICs from eFuse.
+ This is a driver to access hardware related data like
+ soc revision, IDCODE... etc by using the firmware
+ interface.

- This driver can also be built as a module. If so, the module
- will be called nvmem-sc27xx-efuse.
+ If sure, say yes. If unsure, say no.

endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 4e8c616..0b3abd7 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -39,5 +39,6 @@ obj-$(CONFIG_NVMEM_SNVS_LPGPR) += nvmem_snvs_lpgpr.o
nvmem_snvs_lpgpr-y := snvs_lpgpr.o
obj-$(CONFIG_RAVE_SP_EEPROM) += nvmem-rave-sp-eeprom.o
nvmem-rave-sp-eeprom-y := rave-sp-eeprom.o
-obj-$(CONFIG_SC27XX_EFUSE) += nvmem-sc27xx-efuse.o
-nvmem-sc27xx-efuse-y := sc27xx-efuse.o
+obj-$(CONFIG_NVMEM_ZYNQMP) += nvmem_zynqmp_nvmem.o
+nvmem_zynqmp_nvmem-y := zynqmp_nvmem.o
+
diff --git a/drivers/nvmem/zynqmp_nvmem.c b/drivers/nvmem/zynqmp_nvmem.c
new file mode 100644
index 0000000..b910864
--- /dev/null
+++ b/drivers/nvmem/zynqmp_nvmem.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Xilinx, Inc.
+ */
+
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/firmware/xlnx-zynqmp.h>
+
+#define SILICON_REVISION_MASK 0xF
+
+struct zynqmp_nvmem_data {
+ struct device *dev;
+ struct nvmem_device *nvmem;
+};
+
+static int zynqmp_nvmem_read(void *context, unsigned int offset,
+ void *val, size_t bytes)
+{
+ int ret;
+ int idcode, version;
+ struct zynqmp_nvmem_data *priv = context;
+
+ const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
+
+ if (!eemi_ops || !eemi_ops->get_chipid)
+ return -ENXIO;
+
+ ret = eemi_ops->get_chipid(&idcode, &version);
+ if (ret < 0)
+ return ret;
+
+ dev_dbg(priv->dev, "Read chipid val %x %x\n", idcode, version);
+ *(int *)val = version & SILICON_REVISION_MASK;
+
+ return 0;
+}
+
+static struct nvmem_config econfig = {
+ .name = "zynqmp-nvmem",
+ .owner = THIS_MODULE,
+ .word_size = 1,
+ .size = 1,
+ .read_only = true,
+};
+
+static const struct of_device_id zynqmp_nvmem_match[] = {
+ { .compatible = "xlnx,zynqmp-nvmem-fw", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, zynqmp_nvmem_match);
+
+static int zynqmp_nvmem_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct zynqmp_nvmem_data *priv;
+
+ priv = devm_kzalloc(dev, sizeof(struct zynqmp_nvmem_data), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = dev;
+ econfig.dev = dev;
+ econfig.reg_read = zynqmp_nvmem_read;
+ econfig.priv = priv;
+
+ priv->nvmem = devm_nvmem_register(dev, &econfig);
+
+ return PTR_ERR_OR_ZERO(priv->nvmem);
+}
+
+static struct platform_driver zynqmp_nvmem_driver = {
+ .probe = zynqmp_nvmem_probe,
+ .driver = {
+ .name = "zynqmp-nvmem",
+ .of_match_table = zynqmp_nvmem_match,
+ },
+};
+
+module_platform_driver(zynqmp_nvmem_driver);
+
+MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>, Nava kishore Manne <navam@xilinx.com>");
+MODULE_DESCRIPTION("ZynqMP NVMEM driver");
+MODULE_LICENSE("GPL");
--
2.7.4