[PATCH v4 2/2] soc: ti: add k3 platforms chipid module driver

From: Grygorii Strashko
Date: Tue May 12 2020 - 08:35:24 EST

The Texas Instruments K3 Multicore SoC platforms have chipid module which
is represented by CTRLMMR_xxx_JTAGID register and contains information
about SoC id and revision.
Bits:
31-28 VARIANT Device variant
27-12 PARTNO Part number
11-1 MFG Indicates TI as manufacturer (0x17)
1 Always 1

This patch adds corresponding driver to identify the TI K3 SoC family and
revision, and registers this information with the SoC bus. It is available
under /sys/devices/soc0/ for user space, and can be checked, where needed,
in Kernel using soc_device_match().

Identification is done by:
- checking MFG to be TI ID
- retrieving Device variant (revision)
- retrieving Part number and convert it to the family
- retrieving machine from DT "/model"

Example J721E:
# cat /sys/devices/soc0/{machine,family,revision}
Texas Instruments K3 J721E SoC
J721E
SR1.0

Example AM65x:
# cat /sys/devices/soc0/{machine,family,revision}
Texas Instruments AM654 Base Board
AM65X
SR1.0

Cc: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
Reviewed-by: Lokesh Vutla <lokeshvutla@xxxxxx>
Reviewed-by: Tero Kristo <t-kristo@xxxxxx>
---
drivers/soc/ti/Kconfig | 10 +++
drivers/soc/ti/Makefile | 1 +
drivers/soc/ti/k3-socinfo.c | 152 ++++++++++++++++++++++++++++++++++++
3 files changed, 163 insertions(+)
create mode 100644 drivers/soc/ti/k3-socinfo.c

diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig
index 4486e055794c..e192fb788836 100644
--- a/drivers/soc/ti/Kconfig
+++ b/drivers/soc/ti/Kconfig
@@ -91,6 +91,16 @@ config TI_K3_RINGACC
and a consumer. There is one RINGACC module per NAVSS on TI AM65x SoCs
If unsure, say N.

+config TI_K3_SOCINFO
+ bool
+ depends on ARCH_K3 || COMPILE_TEST
+ select SOC_BUS
+ select MFD_SYSCON
+ help
+ Include support for the SoC bus socinfo for the TI K3 Multicore SoC
+ platforms to provide information about the SoC family and
+ variant to user space.
+
endif # SOC_TI

config TI_SCI_INTA_MSI_DOMAIN
diff --git a/drivers/soc/ti/Makefile b/drivers/soc/ti/Makefile
index bec827937a5f..1110e5c98685 100644
--- a/drivers/soc/ti/Makefile
+++ b/drivers/soc/ti/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_WKUP_M3_IPC) += wkup_m3_ipc.o
obj-$(CONFIG_TI_SCI_PM_DOMAINS) += ti_sci_pm_domains.o
obj-$(CONFIG_TI_SCI_INTA_MSI_DOMAIN) += ti_sci_inta_msi.o
obj-$(CONFIG_TI_K3_RINGACC) += k3-ringacc.o
+obj-$(CONFIG_TI_K3_SOCINFO) += k3-socinfo.o
diff --git a/drivers/soc/ti/k3-socinfo.c b/drivers/soc/ti/k3-socinfo.c
new file mode 100644
index 000000000000..af0ba5288e58
--- /dev/null
+++ b/drivers/soc/ti/k3-socinfo.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TI K3 SoC info driver
+ *
+ * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/regmap.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/sys_soc.h>
+
+#define CTRLMMR_WKUP_JTAGID_REG 0
+/*
+ * Bits:
+ * 31-28 VARIANT Device variant
+ * 27-12 PARTNO Part number
+ * 11-1 MFG Indicates TI as manufacturer (0x17)
+ * 1 Always 1
+ */
+#define CTRLMMR_WKUP_JTAGID_VARIANT_SHIFT (28)
+#define CTRLMMR_WKUP_JTAGID_VARIANT_MASK GENMASK(31, 28)
+
+#define CTRLMMR_WKUP_JTAGID_PARTNO_SHIFT (12)
+#define CTRLMMR_WKUP_JTAGID_PARTNO_MASK GENMASK(27, 12)
+
+#define CTRLMMR_WKUP_JTAGID_MFG_SHIFT (1)
+#define CTRLMMR_WKUP_JTAGID_MFG_MASK GENMASK(11, 1)
+
+#define CTRLMMR_WKUP_JTAGID_MFG_TI 0x17
+
+static const struct k3_soc_id {
+ unsigned int id;
+ const char *family_name;
+} k3_soc_ids[] = {
+ { 0xBB5A, "AM65X" },
+ { 0xBB64, "J721E" },
+};
+
+static int
+k3_chipinfo_partno_to_names(unsigned int partno,
+ struct soc_device_attribute *soc_dev_attr)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(k3_soc_ids); i++)
+ if (partno == k3_soc_ids[i].id) {
+ soc_dev_attr->family = k3_soc_ids[i].family_name;
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int k3_chipinfo_probe(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ struct soc_device_attribute *soc_dev_attr;
+ struct device *dev = &pdev->dev;
+ struct soc_device *soc_dev;
+ struct regmap *regmap;
+ u32 partno_id;
+ u32 variant;
+ u32 jtag_id;
+ u32 mfg;
+ int ret;
+
+ regmap = device_node_to_regmap(node);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ ret = regmap_read(regmap, CTRLMMR_WKUP_JTAGID_REG, &jtag_id);
+ if (ret < 0)
+ return ret;
+
+ mfg = (jtag_id & CTRLMMR_WKUP_JTAGID_MFG_MASK) >>
+ CTRLMMR_WKUP_JTAGID_MFG_SHIFT;
+
+ if (mfg != CTRLMMR_WKUP_JTAGID_MFG_TI) {
+ dev_err(dev, "Invalid MFG SoC\n");
+ return -ENODEV;
+ }
+
+ variant = (jtag_id & CTRLMMR_WKUP_JTAGID_VARIANT_MASK) >>
+ CTRLMMR_WKUP_JTAGID_VARIANT_SHIFT;
+ variant++;
+
+ partno_id = (jtag_id & CTRLMMR_WKUP_JTAGID_PARTNO_MASK) >>
+ CTRLMMR_WKUP_JTAGID_PARTNO_SHIFT;
+
+ soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+ if (!soc_dev_attr)
+ return -ENOMEM;
+
+ soc_dev_attr->revision = kasprintf(GFP_KERNEL, "SR%x.0", variant);
+ if (!soc_dev_attr->revision) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ ret = k3_chipinfo_partno_to_names(partno_id, soc_dev_attr);
+ if (ret) {
+ dev_err(dev, "Unknown SoC JTAGID[0x%08X]\n", jtag_id);
+ ret = -ENODEV;
+ goto err_free_rev;
+ }
+
+ node = of_find_node_by_path("/");
+ of_property_read_string(node, "model", &soc_dev_attr->machine);
+ of_node_put(node);
+
+ soc_dev = soc_device_register(soc_dev_attr);
+ if (IS_ERR(soc_dev)) {
+ ret = PTR_ERR(soc_dev);
+ goto err_free_rev;
+ }
+
+ dev_info(dev, "Family:%s rev:%s JTAGID[0x%08x] Detected\n",
+ soc_dev_attr->family,
+ soc_dev_attr->revision, jtag_id);
+
+ return 0;
+
+err_free_rev:
+ kfree(soc_dev_attr->revision);
+err:
+ kfree(soc_dev_attr);
+ return ret;
+}
+
+static const struct of_device_id k3_chipinfo_of_match[] = {
+ { .compatible = "ti,am654-chipid", },
+ { /* sentinel */ },
+};
+
+static struct platform_driver k3_chipinfo_driver = {
+ .driver = {
+ .name = "k3-chipinfo",
+ .of_match_table = k3_chipinfo_of_match,
+ },
+ .probe = k3_chipinfo_probe,
+};
+
+static int __init k3_chipinfo_init(void)
+{
+ return platform_driver_register(&k3_chipinfo_driver);
+}
+subsys_initcall(k3_chipinfo_init);
--
2.17.1