The driver provides information about the Action Semi Owl family of
SoCs (S500, S700 and S900) to user space via sysfs: machine, family,
soc_id, serial_number.
Note the serial number is currently provided only for the S500 SoC
variant.
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxx>
---
drivers/soc/actions/Kconfig | 8 ++
drivers/soc/actions/Makefile | 1 +
drivers/soc/actions/owl-socinfo.c | 133 ++++++++++++++++++++++++++++++
3 files changed, 142 insertions(+)
create mode 100644 drivers/soc/actions/owl-socinfo.c
diff --git a/drivers/soc/actions/Kconfig b/drivers/soc/actions/Kconfig
index 1aca2058a40c..15faade9282d 100644
--- a/drivers/soc/actions/Kconfig
+++ b/drivers/soc/actions/Kconfig
@@ -14,4 +14,12 @@ config OWL_PM_DOMAINS
power-gating on Actions Semiconductor S500, S700 and S900 SoCs.
If unsure, say 'n'.
+config OWL_SOCINFO
+ bool "Actions Semi Owl SoC info driver"
+ default ARCH_ACTIONS
+ select SOC_BUS
+ help
+ Say 'y' here to support the Action Semiconductor Owl socinfo
+ driver, providing information about the SoC to user space.
+
endif
diff --git a/drivers/soc/actions/Makefile b/drivers/soc/actions/Makefile
index 4db9e7b050e5..4b2591d3089f 100644
--- a/drivers/soc/actions/Makefile
+++ b/drivers/soc/actions/Makefile
@@ -2,3 +2,4 @@
obj-$(CONFIG_OWL_PM_DOMAINS_HELPER) += owl-sps-helper.o
obj-$(CONFIG_OWL_PM_DOMAINS) += owl-sps.o
+obj-$(CONFIG_OWL_SOCINFO) += owl-socinfo.o
diff --git a/drivers/soc/actions/owl-socinfo.c b/drivers/soc/actions/owl-socinfo.c
new file mode 100644
index 000000000000..2786c4fd261c
--- /dev/null
+++ b/drivers/soc/actions/owl-socinfo.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Actions Semi Owl SoC information driver
+ *
+ * Copyright (c) 2021 Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxx>
+ */
+
+#include <linux/highmem.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/random.h>
+#include <linux/sys_soc.h>
+
+#include <asm/system_info.h>
+
+struct owl_soc_info {
+ char *name;
+ int (*get_system_serial)(struct device *dev);
+};
+
+static int __init owl_read_sn_from_mem(struct device *dev)
+{
+ int paddrs[2] = {0};
+ char *vaddr;
+ int ret;
+
+ ret = device_property_read_u32_array(dev,
+ "actions,serial-number-addrs",
+ paddrs, 2);
+ if (ret) {
+ dev_err(dev, "failed to read SoC S/N addresses: %d\n", ret);
+ return ret;
+ }
+
+ if (PHYS_PFN(paddrs[0]) != PHYS_PFN(paddrs[1])) {
+ dev_err(dev, "invalid SoC S/N addresses\n");
+ return -EINVAL;
+ }
+
+ vaddr = kmap_local_pfn(PHYS_PFN(paddrs[0]));
+
+ memcpy(&system_serial_low, vaddr + (paddrs[0] & (PAGE_SIZE - 1)),
+ sizeof(system_serial_low));
+ memcpy(&system_serial_high, vaddr + (paddrs[1] & (PAGE_SIZE - 1)),
+ sizeof(system_serial_high));
+
+ kunmap_local(vaddr);
+
+ return 0;
+}
+
+static int owl_socinfo_probe(struct platform_device *pdev)
+{
+ const struct owl_soc_info *soc_info;
+ struct soc_device_attribute *soc_dev_attr;
+ struct soc_device *soc_dev;
+ int ret;
+
+ soc_info = of_device_get_match_data(&pdev->dev);
+ if (!soc_info)
+ return -ENODEV;
+
+ soc_dev_attr = devm_kzalloc(&pdev->dev, sizeof(*soc_dev_attr),
+ GFP_KERNEL);
+ if (!soc_dev_attr)
+ return -ENOMEM;
+
+ ret = of_property_read_string(of_root, "model", &soc_dev_attr->machine);
+ if (ret)
+ return ret;
+
+ soc_dev_attr->family = "Actions Semi Owl";
+ soc_dev_attr->soc_id = soc_info->name;
+
+ if (soc_info->get_system_serial) {
+ ret = soc_info->get_system_serial(&pdev->dev);
+ if (!ret) {
+ soc_dev_attr->serial_number = devm_kasprintf(&pdev->dev,
+ GFP_KERNEL, "%08x%08x",
+ system_serial_high,
+ system_serial_low);
+ /* Feed the SoC unique data into entropy pool. */
+ add_device_randomness(soc_dev_attr->serial_number, 16);
+ }
+ }
+
+ soc_dev = soc_device_register(soc_dev_attr);
+ if (IS_ERR(soc_dev))
+ return dev_err_probe(&pdev->dev, PTR_ERR(soc_dev),
+ "failed to register soc device");
+
+ dev_info(soc_device_to_device(soc_dev),
+ "SoC: %s %s\n",
+ soc_dev_attr->family, soc_dev_attr->soc_id);
+
+ return 0;
+}
+
+static const struct owl_soc_info s500_soc_info = {
+ .name = "S500",
+ .get_system_serial = owl_read_sn_from_mem,
+};
+
+static const struct owl_soc_info s700_soc_info = {
+ .name = "S700",
+ /* FIXME: provide get_system_serial */
+};
+
+static const struct owl_soc_info s900_soc_info = {
+ .name = "S900",
+ /* FIXME: provide get_system_serial */
+};
+
+static const struct of_device_id owl_soc_of_match[] = {
+ { .compatible = "actions,s500-soc", .data = &s500_soc_info, },
+ { .compatible = "actions,s700-soc", .data = &s700_soc_info, },
+ { .compatible = "actions,s900-soc", .data = &s900_soc_info, },
+ { }
+};
+
+static struct platform_driver owl_socinfo_platform_driver = {
+ .probe = owl_socinfo_probe,
+ .driver = {
+ .name = "owl-socinfo",
+ .of_match_table = owl_soc_of_match,
+ },
+};
+
+static int __init owl_socinfo_init(void)
+{
+ return platform_driver_register(&owl_socinfo_platform_driver);
+}
+subsys_initcall(owl_socinfo_init);
--
2.31.0
