> From: Anson Huang
> Sent: Thursday, May 16, 2019 11:25 AM
>
> 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,
This is still follow a generic soc driver design.
I wonder if this is still needed after separate scu soc driver from imx8m.
If not needed, this driver probably could be simplied a lot.
> +};
> +
> +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);
Use of_find_compatible_node instead.
Then you remove two unnecessary local variable.
BTW, probably a better way is to match "fsl,imx-scu"?
> + 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;
Please double check if we really need a global imx_scu_soc_pdev.
Regards
Dong Aisheng
> +
> + return 0;
> +
> +unreg_platform_driver:
> + platform_driver_unregister(&imx_scu_soc_driver);
> + return ret;
> +}
> +device_initcall(imx_scu_soc_init);
> --
> 2.7.4
