Add i.MX SCU SoC info driver to support i.MX8QXP SoC, introduce
driver dependency into Kconfig as CONFIG_IMX_SCU must be
selected to support i.MX SCU SoC driver, also need to use
platform driver model to make sure IMX_SCU driver is probed
before i.MX SCU SoC driver.

With this patch, SoC info can be read from sysfs:

i.mx8qxp-mek# cat /sys/devices/soc0/family
Freescale i.MX

i.mx8qxp-mek# cat /sys/devices/soc0/soc_id
i.MX8QXP

i.mx8qxp-mek# cat /sys/devices/soc0/machine
Freescale i.MX8QXP MEK

i.mx8qxp-mek# cat /sys/devices/soc0/revision
1.1

Signed-off-by: Anson Huang <anson.hu...@nxp.com>
---
Changes since V2:
        - using device_initcall instead of module_init;
        - check of_match_node in init function and ONLY register platform 
driver when matched, this
          is to avoid unnecessary probe for non SCU based i.MX8 SoCs.
---
 drivers/soc/imx/Kconfig       |   9 +++
 drivers/soc/imx/Makefile      |   1 +
 drivers/soc/imx/soc-imx-scu.c | 173 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 183 insertions(+)
 create mode 100644 drivers/soc/imx/soc-imx-scu.c

diff --git a/drivers/soc/imx/Kconfig b/drivers/soc/imx/Kconfig
index d80f899..cbc1a41 100644
--- a/drivers/soc/imx/Kconfig
+++ b/drivers/soc/imx/Kconfig
@@ -7,4 +7,13 @@ config IMX_GPCV2_PM_DOMAINS
        select PM_GENERIC_DOMAINS
        default y if SOC_IMX7D
 
+config IMX_SCU_SOC
+       bool "i.MX System Controller Unit SoC info support"
+       depends on IMX_SCU
+       select SOC_BUS
+       help
+         If you say yes here you get support for the NXP i.MX System
+         Controller Unit SoC info module, it will provide the SoC info
+         like SoC family, ID and revision etc.
+
 endmenu
diff --git a/drivers/soc/imx/Makefile b/drivers/soc/imx/Makefile
index d6b529e0..ddf343d 100644
--- a/drivers/soc/imx/Makefile
+++ b/drivers/soc/imx/Makefile
@@ -1,3 +1,4 @@
 obj-$(CONFIG_HAVE_IMX_GPC) += gpc.o
 obj-$(CONFIG_IMX_GPCV2_PM_DOMAINS) += gpcv2.o
 obj-$(CONFIG_ARCH_MXC) += soc-imx8.o
+obj-$(CONFIG_IMX_SCU_SOC) += soc-imx-scu.o
diff --git a/drivers/soc/imx/soc-imx-scu.c b/drivers/soc/imx/soc-imx-scu.c
new file mode 100644
index 0000000..243c418
--- /dev/null
+++ b/drivers/soc/imx/soc-imx-scu.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <dt-bindings/firmware/imx/rsrc.h>
+#include <linux/firmware/imx/sci.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+
+#define IMX_SCU_SOC_DRIVER_NAME                "imx-scu-soc"
+
+static struct imx_sc_ipc *soc_ipc_handle;
+static struct platform_device *imx_scu_soc_pdev;
+
+struct imx_sc_msg_misc_get_soc_id {
+       struct imx_sc_rpc_msg hdr;
+       union {
+               struct {
+                       u32 control;
+                       u16 resource;
+               } send;
+               struct {
+                       u32 id;
+                       u16 reserved;
+               } resp;
+       } data;
+} __packed;
+
+struct imx_scu_soc_data {
+       char *name;
+       u32 (*soc_revision)(void);
+};
+
+static u32 imx8qxp_soc_revision(void)
+{
+       struct imx_sc_msg_misc_get_soc_id msg;
+       struct imx_sc_rpc_msg *hdr = &msg.hdr;
+       u32 rev;
+       int ret;
+
+       hdr->ver = IMX_SC_RPC_VERSION;
+       hdr->svc = IMX_SC_RPC_SVC_MISC;
+       hdr->func = IMX_SC_MISC_FUNC_GET_CONTROL;
+       hdr->size = 3;
+
+       msg.data.send.control = IMX_SC_C_ID;
+       msg.data.send.resource = IMX_SC_R_SYSTEM;
+
+       ret = imx_scu_call_rpc(soc_ipc_handle, &msg, true);
+       if (ret) {
+               dev_err(&imx_scu_soc_pdev->dev,
+                       "get soc info failed, ret %d\n", ret);
+               /* return 0 means getting revision failed */
+               return 0;
+       }
+
+       /* format revision value passed from SCU firmware */
+       rev = (msg.data.resp.id >> 5) & 0xf;
+       rev = (((rev >> 2) + 1) << 4) | (rev & 0x3);
+
+       return rev;
+}
+
+static const struct imx_scu_soc_data imx8qxp_soc_data = {
+       .name = "i.MX8QXP",
+       .soc_revision = imx8qxp_soc_revision,
+};
+
+static const struct of_device_id imx_scu_soc_match[] = {
+       { .compatible = "fsl,imx8qxp", .data = &imx8qxp_soc_data, },
+       { }
+};
+
+#define imx_scu_revision(soc_rev) \
+       soc_rev ? \
+       kasprintf(GFP_KERNEL, "%d.%d", (soc_rev >> 4) & 0xf,  soc_rev & 0xf) : \
+       "unknown"
+
+static int imx_scu_soc_probe(struct platform_device *pdev)
+{
+       struct soc_device_attribute *soc_dev_attr;
+       const struct imx_scu_soc_data *data;
+       const struct of_device_id *id;
+       struct soc_device *soc_dev;
+       u32 soc_rev = 0;
+       int ret;
+
+       /* wait i.MX SCU driver ready */
+       ret = imx_scu_get_handle(&soc_ipc_handle);
+       if (ret)
+               return ret;
+
+       soc_dev_attr = devm_kzalloc(&pdev->dev, sizeof(*soc_dev_attr),
+                                   GFP_KERNEL);
+       if (!soc_dev_attr)
+               return -ENOMEM;
+
+       soc_dev_attr->family = "Freescale i.MX";
+
+       ret = of_property_read_string(pdev->dev.of_node,
+                                     "model",
+                                     &soc_dev_attr->machine);
+       if (ret)
+               return ret;
+
+       id = of_match_node(imx_scu_soc_match, pdev->dev.of_node);
+       data = id->data;
+       if (data) {
+               soc_dev_attr->soc_id = data->name;
+               if (data->soc_revision)
+                       soc_rev = data->soc_revision();
+       }
+
+       soc_dev_attr->revision = imx_scu_revision(soc_rev);
+       if (!soc_dev_attr->revision)
+               return -ENODEV;
+
+       soc_dev = soc_device_register(soc_dev_attr);
+       if (IS_ERR(soc_dev)) {
+               kfree(soc_dev_attr->revision);
+               return PTR_ERR(soc_dev);
+       }
+
+       return 0;
+}
+
+static struct platform_driver imx_scu_soc_driver = {
+       .driver = {
+               .name = IMX_SCU_SOC_DRIVER_NAME,
+       },
+       .probe = imx_scu_soc_probe,
+};
+
+static int __init imx_scu_soc_init(void)
+{
+       const struct of_device_id *id;
+       struct device_node *root;
+       int ret;
+
+       root = of_find_node_by_path("/");
+       id = of_match_node(imx_scu_soc_match, root);
+       if (!id) {
+               of_node_put(root);
+               return -ENODEV;
+       }
+
+       ret = platform_driver_register(&imx_scu_soc_driver);
+       if (ret)
+               return ret;
+
+       imx_scu_soc_pdev =
+               platform_device_register_simple(IMX_SCU_SOC_DRIVER_NAME,
+                                               -1,
+                                               NULL,
+                                               0);
+       if (IS_ERR(imx_scu_soc_pdev)) {
+               ret = PTR_ERR(imx_scu_soc_pdev);
+               goto unreg_platform_driver;
+       }
+
+       imx_scu_soc_pdev->dev.of_node = root;
+
+       return 0;
+
+unreg_platform_driver:
+       platform_driver_unregister(&imx_scu_soc_driver);
+       return ret;
+}
+device_initcall(imx_scu_soc_init);
-- 
2.7.4

Reply via email to