Re: [PATCH RESEND v3 1/2] soc: hisilicon: Support HCCS driver on Kunpeng SoC

From: lihuisong (C)
Date: Wed Jul 26 2023 - 23:51:41 EST



在 2023/7/26 17:54, lihuisong (C) 写道:
Hi Wei,

Thanks for your review.


在 2023/7/25 16:55, Wei Xu 写道:
Hi Huisong,

On 2023/7/25 15:57, Huisong Li wrote:
The Huawei Cache-Coherent System (HCCS) is a bus protocol standard
for ensuring cache coherent on HiSilicon SoC. The performance of
the application may be affected if some hccs ports are in non-full
lane status, have a large number of CRC errors and so on.

This driver provides the query interface of the health status and
port information of HCCS on Kunpeng SoC.

Signed-off-by: Huisong Li <lihuisong@xxxxxxxxxx>
---
  MAINTAINERS                          |    6 +
  drivers/soc/Kconfig                  |    1 +
  drivers/soc/Makefile                 |    1 +
  drivers/soc/hisilicon/Kconfig        |   19 +
  drivers/soc/hisilicon/Makefile       |    2 +
  drivers/soc/hisilicon/kunpeng_hccs.c | 1288 ++++++++++++++++++++++++++
  drivers/soc/hisilicon/kunpeng_hccs.h |  196 ++++
  7 files changed, 1513 insertions(+)
  create mode 100644 drivers/soc/hisilicon/Kconfig
  create mode 100644 drivers/soc/hisilicon/Makefile
  create mode 100644 drivers/soc/hisilicon/kunpeng_hccs.c
  create mode 100644 drivers/soc/hisilicon/kunpeng_hccs.h

diff --git a/MAINTAINERS b/MAINTAINERS
index a5c16bb92fe2..4e55ff992171 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9471,6 +9471,12 @@ S:    Maintained
  F:    Documentation/ABI/testing/debugfs-hisi-zip
  F:    drivers/crypto/hisilicon/zip/
  +HISILICON KUNPENG SOC HCCS DRIVER
+M:    Huisong Li <lihuisong@xxxxxxxxxx>
+S:    Maintained
+F:    drivers/soc/hisilicon/kunpeng_hccs.c
+F:    drivers/soc/hisilicon/kunpeng_hccs.h
+
  HMM - Heterogeneous Memory Management
  M:    Jérôme Glisse <jglisse@xxxxxxxxxx>
  L:    linux-mm@xxxxxxxxx
diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index 4e176280113a..d21e75d69294 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -10,6 +10,7 @@ source "drivers/soc/bcm/Kconfig"
  source "drivers/soc/canaan/Kconfig"
  source "drivers/soc/fsl/Kconfig"
  source "drivers/soc/fujitsu/Kconfig"
+source "drivers/soc/hisilicon/Kconfig"
  source "drivers/soc/imx/Kconfig"
  source "drivers/soc/ixp4xx/Kconfig"
  source "drivers/soc/litex/Kconfig"
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index 3b0f9fb3b5c8..531f46f3ad98 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_MACH_DOVE)        += dove/
  obj-y                += fsl/
  obj-y                += fujitsu/
  obj-$(CONFIG_ARCH_GEMINI)    += gemini/
+obj-y                += hisilicon/
  obj-y                += imx/
  obj-y                += ixp4xx/
  obj-$(CONFIG_SOC_XWAY)        += lantiq/
diff --git a/drivers/soc/hisilicon/Kconfig b/drivers/soc/hisilicon/Kconfig
new file mode 100644
index 000000000000..87a1f15cbedb
--- /dev/null
+++ b/drivers/soc/hisilicon/Kconfig
@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menu "Hisilicon SoC drivers"
+    depends on ARCH_HISI || COMPILE_TEST
+
+config KUNPENG_HCCS
+    tristate "HCCS driver on Kunpeng SoC"
+    depends on ACPI
+    depends on ARM64 || COMPILE_TEST
+    help
+      The Huawei Cache-Coherent System (HCCS) is a bus protocol standard
+      for ensuring cache coherent on HiSilicon SoC. The performance of
+      the application may be affected if some hccs ports are in non-full
+      lane status, have a large number of CRC errors and so on.
+
+      Say M here if you want to include support for querying the health
+      status and port information of HCCS on Kunpeng SoC.
+
+endmenu
diff --git a/drivers/soc/hisilicon/Makefile b/drivers/soc/hisilicon/Makefile
new file mode 100644
index 000000000000..226e747e70d6
--- /dev/null
+++ b/drivers/soc/hisilicon/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_KUNPENG_HCCS)    += kunpeng_hccs.o
diff --git a/drivers/soc/hisilicon/kunpeng_hccs.c b/drivers/soc/hisilicon/kunpeng_hccs.c
new file mode 100644
index 000000000000..d7f4bb04deb3
--- /dev/null
+++ b/drivers/soc/hisilicon/kunpeng_hccs.c
@@ -0,0 +1,1288 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * The Huawei Cache-Coherent System (HCCS) is a bus protocol standard for
+ * ensuring cache coherent on HiSilicon SoC.
+ *
+ * Copyright (c) 2023 Hisilicon Limited.
+ * Author: Huisong Li <lihuisong@xxxxxxxxxx>
+ *
+ * HCCS driver for Kunpeng SoC provides the following features:
+ * - Retrieve the following information about each port:
+ *    - port type
+ *    - lane mode
+ *    - enable
+ *    - current lane mode
+ *    - link state machine
+ *    - lane mask
+ *    - CRC error count
+ *
+ * - Retrieve the following information about all the ports on the chip or
+ *   the die:
+ *    - if all enabled ports are in linked
+ *    - if all linked ports are in full lane
+ *    - CRC error count sum
+ */
+#include <linux/sysfs.h>
+#include <linux/acpi.h>
+#include <linux/io.h>
+#include <linux/kobject.h>
Please remove the useless including of the io.h and kobject.h.
useless header, indeed. will remove in v4.

+#include <linux/iopoll.h>
+#include <linux/platform_device.h>
It is better to put all the linux headers into alphabetical order.
Ack

+#include <acpi/pcc.h>
+
+#include "kunpeng_hccs.h"
+
+/* PCC defines */
+#define HCCS_PCC_SIGNATURE_MASK        0x50434300
+#define HCCS_PCC_STATUS_CMD_COMPLETE    BIT(0)
+
+/*
+ * Arbitrary retries in case the remote processor is slow to respond
+ * to PCC commands
+ */
+#define HCCS_PCC_CMD_WAIT_RETRIES_NUM        500ULL
+#define HCCS_POLL_STATUS_TIME_INTERVAL_US    3
+
+static struct hccs_port_info *kobj_to_port_info(struct kobject *k)
+{
+    return container_of(k, struct hccs_port_info, kobj);
+}
+
+static struct hccs_die_info *kobj_to_die_info(struct kobject *k)
+{
+    return container_of(k, struct hccs_die_info, kobj);
+}
+
+static struct hccs_chip_info *kobj_to_chip_info(struct kobject *k)
+{
+    return container_of(k, struct hccs_chip_info, kobj);
+}
+
+struct hccs_register_ctx {
+    struct device *dev;
+    u8 chan_id;
+    int err;
+};
+
+static acpi_status hccs_get_register_cb(struct acpi_resource *ares,
+                    void *context)
+{
+    struct acpi_resource_generic_register *reg;
+    struct hccs_register_ctx *ctx = context;
+
+    if (ares->type != ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
+        return AE_OK;
+
+    reg = &ares->data.generic_reg;
+    if (reg->space_id != ACPI_ADR_SPACE_PLATFORM_COMM) {
+        dev_err(ctx->dev, "Bad register resource.\n");
+        ctx->err = -EINVAL;
+        return AE_ERROR;
+    }
+    ctx->chan_id = reg->access_size;
+
+    return AE_OK;
+}
+
+static int hccs_get_pcc_chan_id(struct hccs_dev *hdev)
+{
+    acpi_handle handle = ACPI_HANDLE(hdev->dev);
+    struct hccs_register_ctx ctx = {0};
+    acpi_status status;
+
+    if (!acpi_has_method(handle, METHOD_NAME__CRS))
+        return -ENODEV;
+
+    ctx.dev = hdev->dev;
+    status = acpi_walk_resources(handle, METHOD_NAME__CRS,
+                     hccs_get_register_cb, &ctx);
+    if (ACPI_FAILURE(status))
+        return ctx.err;
+    hdev->chan_id = ctx.chan_id;
+
+    return 0;
+}
+
+static void hccs_chan_tx_done(struct mbox_client *cl, void *msg, int ret)
+{
+    if (ret < 0)
+        pr_debug("TX did not complete: CMD sent:0x%x, ret:%d\n",
+             *(u8 *)msg, ret);
+    else
+        pr_debug("TX completed. CMD sent:0x%x, ret:%d\n",
+             *(u8 *)msg, ret);
+}
+
+static void hccs_unregister_pcc_channel(struct hccs_dev *hdev)
+{
+    struct hccs_mbox_client_info *cl_info = &hdev->cl_info;
+
+    if (cl_info->pcc_comm_addr)
+        iounmap(cl_info->pcc_comm_addr);
+    pcc_mbox_free_channel(hdev->cl_info.pcc_chan);
+}
+
+static int hccs_register_pcc_channel(struct hccs_dev *hdev)
+{
+    struct hccs_mbox_client_info *cl_info = &hdev->cl_info;
+    struct mbox_client *cl = &cl_info->client;
+    struct pcc_mbox_chan *pcc_chan;
+    struct device *dev = hdev->dev;
+    int rc;
+
+    cl->dev = dev;
+    cl->tx_block = false;
+    cl->knows_txdone = true;
+    cl->tx_done = hccs_chan_tx_done;
+    pcc_chan = pcc_mbox_request_channel(cl, hdev->chan_id);
+    if (IS_ERR(pcc_chan)) {
+        dev_err(dev, "PPC channel request failed.\n");
+        rc = -ENODEV;
+        goto out;
+    }
+    cl_info->pcc_chan = pcc_chan;
+    cl_info->mbox_chan = pcc_chan->mchan;
+
+    /*
+     * pcc_chan->latency is just a nominal value. In reality the remote
+     * processor could be much slower to reply. So add an arbitrary amount
+     * of wait on top of nominal.
+     */
+    cl_info->deadline_us =
+            HCCS_PCC_CMD_WAIT_RETRIES_NUM * pcc_chan->latency;
+    if (cl_info->mbox_chan->mbox->txdone_irq) {
+        dev_err(dev, "PCC IRQ in PCCT is enabled.\n");
+        rc = -EINVAL;
+        goto err_mbx_channel_free;
+    }
+
+    if (pcc_chan->shmem_base_addr) {
+        cl_info->pcc_comm_addr = (void __force *)ioremap(
+            pcc_chan->shmem_base_addr, pcc_chan->shmem_size);
+        if (!cl_info->pcc_comm_addr) {
+            dev_err(dev, "Failed to ioremap PCC communication region for channel-%d.\n",
+                hdev->chan_id);
+            rc = -ENOMEM;
+            goto err_mbx_channel_free;
+        }
+    }
+
+    return 0;
+
+err_mbx_channel_free:
+    pcc_mbox_free_channel(cl_info->pcc_chan);
+out:
+    return rc;
+}
+
+static int hccs_check_chan_cmd_complete(struct hccs_dev *hdev)
+{
+    struct hccs_mbox_client_info *cl_info = &hdev->cl_info;
+    struct acpi_pcct_shared_memory *comm_base = cl_info->pcc_comm_addr;
+    u16 status;
+    int ret;
+
+    /*
+     * Poll PCC status register every 3us(delay_us) for maximum of
+     * deadline_us(timeout_us) until PCC command complete bit is set(cond)
+     */
+    ret = readw_poll_timeout(&comm_base->status, status,
+                 status & HCCS_PCC_STATUS_CMD_COMPLETE,
+                 HCCS_POLL_STATUS_TIME_INTERVAL_US,
+                 cl_info->deadline_us);
+    if (unlikely(ret))
+        dev_err(hdev->dev, "poll PCC status failed, ret = %d.\n", ret);
+
+    return ret;
+}
+
+static int hccs_pcc_cmd_send(struct hccs_dev *hdev, u8 cmd,
+                 struct hccs_desc *desc)
+{
+    struct hccs_mbox_client_info *cl_info = &hdev->cl_info;
+    struct acpi_pcct_shared_memory *comm_base = cl_info->pcc_comm_addr;
+    void *comm_space = (void *)(comm_base + 1);
+    struct hccs_fw_inner_head *fw_inner_head;
+    struct acpi_pcct_shared_memory tmp = {0};
+    u16 comm_space_size;
+    int ret;
+
+    /* Write signature for this subspace */
+    tmp.signature = HCCS_PCC_SIGNATURE_MASK | hdev->chan_id;
+    /* Write to the shared command region */
+    tmp.command = cmd;
+    /* Clear cmd complete bit */
+    tmp.status = 0;
+    memcpy_toio(comm_base, (void *)&tmp,
+            sizeof(struct acpi_pcct_shared_memory));
+
+    /* Copy the message to the PCC comm space */
+    comm_space_size = HCCS_PCC_SHARE_MEM_BYTES -
+                sizeof(struct acpi_pcct_shared_memory);
+    memcpy_toio(comm_space, (void *)desc, comm_space_size);
+
+    /* Ring doorbell */
+    ret = mbox_send_message(cl_info->mbox_chan, &cmd);
+    if (ret < 0) {
+        dev_err(hdev->dev, "Send PCC mbox message failed, ret = %d.\n",
+            ret);
+        goto end;
+    }
+
+    /* Wait for completion */
+    ret = hccs_check_chan_cmd_complete(hdev);
+    if (ret)
+        goto end;
+
+    /* Copy response data */
+    memcpy_fromio((void *)desc, comm_space, comm_space_size);
+    fw_inner_head = &desc->rsp.fw_inner_head;
+    if (fw_inner_head->retStatus) {
+        dev_err(hdev->dev, "Execute PCC command failed, error code = %u.\n",
+            fw_inner_head->retStatus);
+        ret = -EIO;
+    }
+
+end:
+    mbox_client_txdone(cl_info->mbox_chan, ret);
+    return ret;
+}
+
+static void hccs_init_req_desc(struct hccs_desc *desc)
+{
+    struct hccs_req_desc *req = &desc->req;
+
+    memset(desc, 0, sizeof(*desc));
+    req->req_head.module_code = HCCS_SERDES_MODULE_CODE;
+}
+
+static int hccs_get_dev_caps(struct hccs_dev *hdev)
+{
+    struct hccs_desc desc;
+    int ret;
+
+    hccs_init_req_desc(&desc);
+    ret = hccs_pcc_cmd_send(hdev, HCCS_GET_DEV_CAP, &desc);
+    if (ret) {
+        dev_err(hdev->dev, "Get device capabilities failed, ret = %d.\n",
+            ret);
+        return ret;
+    }
+    memcpy(&hdev->caps, desc.rsp.data, sizeof(hdev->caps));
+
+    return 0;
+}
+
+static int hccs_query_chip_num_on_platform(struct hccs_dev *hdev)
+{
+    struct hccs_desc desc;
+    int ret;
+
+    hccs_init_req_desc(&desc);
+    ret = hccs_pcc_cmd_send(hdev, HCCS_GET_CHIP_NUM, &desc);
+    if (ret) {
+        dev_err(hdev->dev, "query system chip number failed, ret = %d.\n",
+            ret);
+        return ret;
+    }
+
+    hdev->chip_num = *((u8 *)&desc.rsp.data);
+    if (!hdev->chip_num) {
+        dev_err(hdev->dev, "chip num obtained from firmware is zero.\n");
+        return -EINVAL;
+    }
+
+    return 0;
+}
+
+static int hccs_get_chip_info(struct hccs_dev *hdev,
+                  struct hccs_chip_info *chip)
+{
+    struct hccs_die_num_req_param *req_param;
+    struct hccs_desc desc;
+    int ret;
+
+    hccs_init_req_desc(&desc);
+    req_param = (struct hccs_die_num_req_param *)desc.req.data;
+    req_param->chip_id = chip->chip_id;
+    ret = hccs_pcc_cmd_send(hdev, HCCS_GET_DIE_NUM, &desc);
+    if (ret)
+        return ret;
+
+    chip->die_num = *((u8 *)&desc.rsp.data);
+
+    return 0;
+}
+
+static int hccs_query_chip_info_on_platform(struct hccs_dev *hdev)
+{
+    struct hccs_chip_info *chip;
+    int ret;
+    u8 idx;
+
+    ret = hccs_query_chip_num_on_platform(hdev);
+    if (ret) {
+        dev_err(hdev->dev, "query chip number on platform failed, ret = %d.\n",
+            ret);
+        return ret;
+    }
+
+    hdev->chips = devm_kzalloc(hdev->dev,
+                hdev->chip_num * sizeof(struct hccs_chip_info),
+                GFP_KERNEL);
+    if (!hdev->chips) {
+        dev_err(hdev->dev, "allocate all chips memory failed.\n");
+        return -ENOMEM;
+    }
+
+    for (idx = 0; idx < hdev->chip_num; idx++) {
+        chip = &hdev->chips[idx];
+        chip->chip_id = idx;
+        ret = hccs_get_chip_info(hdev, chip);
+        if (ret) {
+            dev_err(hdev->dev, "get chip%u info failed, ret = %d.\n",
+                idx, ret);
+            return ret;
+        }
+        chip->hdev = hdev;
+    }
+
+    return 0;
+}
+
+static int hccs_query_die_info_on_chip(struct hccs_dev *hdev, u8 chip_id,
+                       u8 die_idx, struct hccs_die_info *die)
+{
+    struct hccs_die_info_req_param *req_param;
+    struct hccs_die_info_rsp_data *rsp_data;
+    struct hccs_desc desc;
+    int ret;
+
+    hccs_init_req_desc(&desc);
+    req_param = (struct hccs_die_info_req_param *)desc.req.data;
+    req_param->chip_id = chip_id;
+    req_param->die_idx = die_idx;
+    ret = hccs_pcc_cmd_send(hdev, HCCS_GET_DIE_INFO, &desc);
+    if (ret)
+        return ret;
+
+    rsp_data = (struct hccs_die_info_rsp_data *)desc.rsp.data;
+    die->die_id = rsp_data->die_id;
+    die->port_num = rsp_data->port_num;
+    die->min_port_id = rsp_data->min_port_id;
+    die->max_port_id = rsp_data->max_port_id;
+    if (die->min_port_id > die->max_port_id) {
+        dev_err(hdev->dev, "min port id(%u) > max port id(%u) on die_idx(%u).\n",
+            die->min_port_id, die->max_port_id, die_idx);
+        return -EINVAL;
+    }
+    if (die->max_port_id > HCCS_DIE_MAX_PORT_ID) {
+        dev_err(hdev->dev, "max port id(%u) on die_idx(%u) is too big.\n",
+            die->max_port_id, die_idx);
+        return -EINVAL;
+    }
+
+    return 0;
+}
+
+static int hccs_query_all_die_info_on_platform(struct hccs_dev *hdev)
+{
+    struct device *dev = hdev->dev;
+    struct hccs_chip_info *chip;
+    struct hccs_die_info *die;
+    u8 i, j;
+    int ret;
+
+    for (i = 0; i < hdev->chip_num; i++) {
+        chip = &hdev->chips[i];
+        if (!chip->die_num)
+            continue;
+
+        chip->dies = devm_kzalloc(hdev->dev,
+                chip->die_num * sizeof(struct hccs_die_info),
+                GFP_KERNEL);
+        if (!chip->dies) {
+            dev_err(dev, "allocate all dies memory on chip%u failed.\n",
+                i);
+            return -ENOMEM;
+        }
+
+        for (j = 0; j < chip->die_num; j++) {
+            die = &chip->dies[j];
+            ret = hccs_query_die_info_on_chip(hdev, i, j, die);
+            if (ret) {
+                dev_err(dev, "get die idx (%u) info on chip%u failed, ret = %d.\n",
+                    j, i, ret);
+                return ret;
+            }
+            die->chip = chip;
+        }
+    }
+
+    return 0;
+}
+
+static int hccs_get_bd_info(struct hccs_dev *hdev, u8 opcode,
+                struct hccs_desc *desc,
+                void *buf, size_t buf_len,
+                struct hccs_rsp_head *rsp_head)
+{
+    struct hccs_rsp_head *head;
+    struct hccs_rsp_desc *rsp;
+    int ret;
+
+    ret = hccs_pcc_cmd_send(hdev, opcode, desc);
+    if (ret)
+        return ret;
+
+    rsp = &desc->rsp;
+    head = &rsp->rsp_head;
+    if (head->data_len > buf_len) {
+        dev_err(hdev->dev,
+            "buffer overflow (buf_len = %lu, data_len = %u)!\n",
+            buf_len, head->data_len);
+        return -ENOMEM;
+    }
+
+    memcpy(buf, rsp->data, head->data_len);
+    *rsp_head = *head;
+
+    return 0;
+}
+
+static int hccs_get_all_port_attr(struct hccs_dev *hdev,
+                  struct hccs_die_info *die,
+                  struct hccs_port_attr *attrs, u16 size)
+{
+    struct hccs_die_comm_req_param *req_param;
+    struct hccs_req_head *req_head;
+    struct hccs_rsp_head rsp_head;
+    struct hccs_desc desc;
+    size_t left_buf_len;
+    u32 data_len = 0;
+    u8 start_id;
+    u8 *buf;
+    int ret;
+
+    buf = (u8 *)attrs;
+    left_buf_len = sizeof(struct hccs_port_attr) * size;
+    start_id = die->min_port_id;
+    while (start_id <= die->max_port_id) {
+        hccs_init_req_desc(&desc);
+        req_head = &desc.req.req_head;
+        req_head->start_id = start_id;
+        req_param = (struct hccs_die_comm_req_param *)desc.req.data;
+        req_param->chip_id = die->chip->chip_id;
+        req_param->die_id = die->die_id;
+
+        ret = hccs_get_bd_info(hdev, HCCS_GET_DIE_PORT_INFO, &desc,
+                       buf + data_len, left_buf_len, &rsp_head);
+        if (ret) {
+            dev_err(hdev->dev,
+                "get the information of port%u on die%u failed, ret = %d.\n",
+                start_id, die->die_id, ret);
+            return ret;
+        }
+
+        data_len += rsp_head.data_len;
+        left_buf_len -= rsp_head.data_len;
+        if (unlikely(rsp_head.next_id <= start_id)) {
+            dev_err(hdev->dev,
+                "next port id (%u) is not greater than last start id (%u) on die%u.\n",
+                rsp_head.next_id, start_id, die->die_id);
+            return -EINVAL;
+        }
+        start_id = rsp_head.next_id;
+    }
+
+    return 0;
+}
+
+static int hccs_get_all_port_info_on_die(struct hccs_dev *hdev,
+                     struct hccs_die_info *die)
+{
+    struct hccs_port_attr *attrs;
+    struct hccs_port_info *port;
+    int ret;
+    u8 i;
+
+    attrs = kcalloc(die->port_num, sizeof(struct hccs_port_attr),
+            GFP_KERNEL);
+    if (!attrs)
+        return -ENOMEM;
+
+    ret = hccs_get_all_port_attr(hdev, die, attrs, die->port_num);
+    if (ret)
+        goto out;
+
+    for (i = 0; i < die->port_num; i++) {
+        port = &die->ports[i];
+        port->port_id = attrs[i].port_id;
+        port->port_type = attrs[i].port_type;
+        port->lane_mode = attrs[i].lane_mode;
+        port->enable = attrs[i].enable;
+        port->die = die;
+    }
+
+out:
+    kfree(attrs);
+    return ret;
+}
+
+static int hccs_query_all_port_info_on_platform(struct hccs_dev *hdev)
+{
+
+    struct device *dev = hdev->dev;
+    struct hccs_chip_info *chip;
+    struct hccs_die_info *die;
+    u8 i, j;
+    int ret;
+
+    for (i = 0; i < hdev->chip_num; i++) {
+        chip = &hdev->chips[i];
+        for (j = 0; j < chip->die_num; j++) {
+            die = &chip->dies[j];
+            if (!die->port_num)
+                continue;
+
+            die->ports = devm_kzalloc(dev,
+                die->port_num * sizeof(struct hccs_port_info),
+                GFP_KERNEL);
+            if (!die->ports) {
+                dev_err(dev, "allocate ports memory on chip%u/die%u failed.\n",
+                    i, die->die_id);
+                return -ENOMEM;
+            }
+
+            ret = hccs_get_all_port_info_on_die(hdev, die);
+            if (ret) {
+                dev_err(dev, "get die(%u) info on chip%u failed, ret = %d.\n",
+                    die->die_id, i, ret);
+                return ret;
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int hccs_get_hw_info(struct hccs_dev *hdev)
+{
+    int ret;
+
+    ret = hccs_query_chip_info_on_platform(hdev);
+    if (ret) {
+        dev_err(hdev->dev, "query chip info on platform failed, ret = %d.\n",
+            ret);
+        return ret;
+    }
+
+    ret = hccs_query_all_die_info_on_platform(hdev);
+    if (ret) {
+        dev_err(hdev->dev, "query all die info on platform failed, ret = %d.\n",
+            ret);
+        return ret;
+    }
+
+    ret = hccs_query_all_port_info_on_platform(hdev);
+    if (ret) {
+        dev_err(hdev->dev, "query all port info on platform failed, ret = %d.\n",
+            ret);
+        return ret;
+    }
+
+    return 0;
+}
+
+static int hccs_query_port_link_status(struct hccs_dev *hdev,
+                       const struct hccs_port_info *port,
+                       struct hccs_link_status *link_status)
+{
+    const struct hccs_die_info *die = port->die;
+    const struct hccs_chip_info *chip = die->chip;
+    struct hccs_port_comm_req_param *req_param;
+    struct hccs_desc desc;
+    int ret;
+
+    hccs_init_req_desc(&desc);
+    req_param = (struct hccs_port_comm_req_param *)desc.req.data;
+    req_param->chip_id = chip->chip_id;
+    req_param->die_id = die->die_id;
+    req_param->port_id = port->port_id;
+    ret = hccs_pcc_cmd_send(hdev, HCCS_GET_PORT_LINK_STATUS, &desc);
+    if (ret) {
+        dev_err(hdev->dev,
+            "get port link status info failed, ret = %d.\n", ret);
+        return ret;
+    }
+
+    *link_status = *((struct hccs_link_status *)desc.rsp.data);
+
+    return 0;
+}
+
+static int hccs_query_port_crc_err_cnt(struct hccs_dev *hdev,
+                       const struct hccs_port_info *port,
+                       u64 *crc_err_cnt)
+{
+    const struct hccs_die_info *die = port->die;
+    const struct hccs_chip_info *chip = die->chip;
+    struct hccs_port_comm_req_param *req_param;
+    struct hccs_desc desc;
+    int ret;
+
+    hccs_init_req_desc(&desc);
+    req_param = (struct hccs_port_comm_req_param *)desc.req.data;
+    req_param->chip_id = chip->chip_id;
+    req_param->die_id = die->die_id;
+    req_param->port_id = port->port_id;
+    ret = hccs_pcc_cmd_send(hdev, HCCS_GET_PORT_CRC_ERR_CNT, &desc);
+    if (ret) {
+        dev_err(hdev->dev,
+            "get port crc error count failed, ret = %d.\n", ret);
+        return ret;
+    }
+
+    memcpy(crc_err_cnt, &desc.rsp.data, sizeof(u64));
+
+    return 0;
+}
+
+static int hccs_get_die_all_link_status(struct hccs_dev *hdev,
+                    const struct hccs_die_info *die,
+                    u8 *all_linked)
+{
+    struct hccs_die_comm_req_param *req_param;
+    struct hccs_desc desc;
+    int ret;
+
+    if (die->port_num == 0) {
+        *all_linked = 1;
+        return 0;
+    }
+
+    hccs_init_req_desc(&desc);
+    req_param = (struct hccs_die_comm_req_param *)desc.req.data;
+    req_param->chip_id = die->chip->chip_id;
+    req_param->die_id = die->die_id;
+    ret = hccs_pcc_cmd_send(hdev, HCCS_GET_DIE_PORTS_LANE_STA, &desc);
+    if (ret) {
+        dev_err(hdev->dev,
+            "get link status of all ports failed on die%u, ret = %d.\n",
+            die->die_id, ret);
+        return ret;
+    }
+
+    *all_linked = *((u8 *)&desc.rsp.data);
+
+    return 0;
+}
+
+static int hccs_get_die_all_port_lane_status(struct hccs_dev *hdev,
+                         const struct hccs_die_info *die,
+                         u8 *full_lane)
+{
+    struct hccs_die_comm_req_param *req_param;
+    struct hccs_desc desc;
+    int ret;
+
+    if (die->port_num == 0) {
+        *full_lane = 1;
+        return 0;
+    }
+
+    hccs_init_req_desc(&desc);
+    req_param = (struct hccs_die_comm_req_param *)desc.req.data;
+    req_param->chip_id = die->chip->chip_id;
+    req_param->die_id = die->die_id;
+    ret = hccs_pcc_cmd_send(hdev, HCCS_GET_DIE_PORTS_LANE_STA, &desc);
+    if (ret) {
+        dev_err(hdev->dev, "get lane status of all ports failed on die%u, ret = %d.\n",
+            die->die_id, ret);
+        return ret;
+    }
+
+    *full_lane = *((u8 *)&desc.rsp.data);
+
+    return 0;
+}
+
+static int hccs_get_die_total_crc_err_cnt(struct hccs_dev *hdev,
+                      const struct hccs_die_info *die,
+                      u64 *total_crc_err_cnt)
+{
+    struct hccs_die_comm_req_param *req_param;
+    struct hccs_desc desc;
+    int ret;
+
+    if (die->port_num == 0) {
+        *total_crc_err_cnt = 0;
+        return 0;
+    }
+
+    hccs_init_req_desc(&desc);
+    req_param = (struct hccs_die_comm_req_param *)desc.req.data;
+    req_param->chip_id = die->chip->chip_id;
+    req_param->die_id = die->die_id;
+    ret = hccs_pcc_cmd_send(hdev, HCCS_GET_DIE_PORTS_CRC_ERR_CNT, &desc);
+    if (ret) {
+        dev_err(hdev->dev, "get crc error count sum failed on die%u, ret = %d.\n",
+            die->die_id, ret);
+        return ret;
+    }
+
+    memcpy(total_crc_err_cnt, &desc.rsp.data, sizeof(u64));
+
+    return 0;
+}
+
+static ssize_t hccs_show(struct kobject *k, struct attribute *attr, char *buf)
+{
+    struct kobj_attribute *kobj_attr;
+
+    kobj_attr = container_of(attr, struct kobj_attribute, attr);
+
+    return kobj_attr->show(k, kobj_attr, buf);
+}
+
+static const struct sysfs_ops hccs_comm_ops = {
+    .show = hccs_show,
+};
+
+static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
+             char *buf)
+{
+    const struct hccs_port_info *port = kobj_to_port_info(kobj);
+
+    return sysfs_emit(buf, "HCCS-v%u\n", port->port_type);
+}
+
+static struct kobj_attribute hccs_type_attr =
+            __ATTR(type, 0444, type_show, NULL);
It is better to use __ATTR_RO.
Ack

+
+static ssize_t lane_mode_show(struct kobject *kobj, struct kobj_attribute *attr,
+                  char *buf)
+{
+    const struct hccs_port_info *port = kobj_to_port_info(kobj);
+
+    return sysfs_emit(buf, "x%u\n", port->lane_mode);
+}
+
+static struct kobj_attribute lane_mode_attr =
+            __ATTR(lane_mode, 0444, lane_mode_show, NULL);
+
+static ssize_t enable_show(struct kobject *kobj,
+                 struct kobj_attribute *attr, char *buf)
+{
+    const struct hccs_port_info *port = kobj_to_port_info(kobj);
+
+    return sysfs_emit(buf, "%u\n", port->enable);
+}
+
+static struct kobj_attribute port_enable_attr =
+            __ATTR(enable, 0444, enable_show, NULL);
Ditto.
Ok, all port attribute definition will be modified.
But the definition of //attributes in chip and die directory cannot use __ATTR_RO,
because the //attribute file //name in two directories are the same and have to need different show() function.

+
+static ssize_t cur_lane_num_show(struct kobject *kobj,
+                 struct kobj_attribute *attr, char *buf)
+{
+    const struct hccs_port_info *port = kobj_to_port_info(kobj);
+    struct hccs_dev *hdev = port->die->chip->hdev;
+    struct hccs_link_status link_status = {0};
+    int ret;
+
+    mutex_lock(&hdev->lock);
+    ret = hccs_query_port_link_status(hdev, port, &link_status);
+    mutex_unlock(&hdev->lock);
+    if (ret)
+        return ret;
+
+    return sysfs_emit(buf, "%u\n", link_status.lane_num);
+}
+
+static struct kobj_attribute cur_lane_num_attr =
+            __ATTR(cur_lane_num, 0444, cur_lane_num_show, NULL);
+
+static ssize_t link_fsm_show(struct kobject *kobj,
+                 struct kobj_attribute *attr, char *buf)
+{
+    const struct hccs_port_info *port = kobj_to_port_info(kobj);
+    struct hccs_dev *hdev = port->die->chip->hdev;
+    struct hccs_link_status link_status = {0};
+    const struct {
+        u8 link_fsm;
+        char *str;
+    } link_fsm_map[] = {
+        {HCCS_PORT_RESET, "reset"},
+        {HCCS_PORT_SETUP, "setup"},
+        {HCCS_PORT_CONFIG, "config"},
+        {HCCS_PORT_READY, "link-up"},
+    };
+    const char *link_fsm_str = "unknown";
+    size_t i;
+    int ret;
+
+    mutex_lock(&hdev->lock);
+    ret = hccs_query_port_link_status(hdev, port, &link_status);
+    mutex_unlock(&hdev->lock);
+    if (ret)
+        return ret;
+
+    for (i = 0; i < ARRAY_SIZE(link_fsm_map); i++) {
+        if (link_fsm_map[i].link_fsm == link_status.link_fsm) {
+            link_fsm_str = link_fsm_map[i].str;
+            break;
+        }
+    }
+
+    return sysfs_emit(buf, "%s\n", link_fsm_str);
+}
+
+static struct kobj_attribute link_fsm_attr =
+            __ATTR(link_fsm, 0444, link_fsm_show, NULL);
+
+static ssize_t lane_mask_show(struct kobject *kobj,
+                  struct kobj_attribute *attr, char *buf)
+{
+    const struct hccs_port_info *port = kobj_to_port_info(kobj);
+    struct hccs_dev *hdev = port->die->chip->hdev;
+    struct hccs_link_status link_status = {0};
+    int ret;
+
+    mutex_lock(&hdev->lock);
+    ret = hccs_query_port_link_status(hdev, port, &link_status);
+    mutex_unlock(&hdev->lock);
+    if (ret)
+        return ret;
+
+    return sysfs_emit(buf, "0x%x\n", link_status.lane_mask);
+}
+
+static struct kobj_attribute lane_mask_attr =
+            __ATTR(lane_mask, 0444, lane_mask_show, NULL);
+
+static ssize_t crc_err_cnt_show(struct kobject *kobj,
+                struct kobj_attribute *attr, char *buf)
+{
+    const struct hccs_port_info *port = kobj_to_port_info(kobj);
+    struct hccs_dev *hdev = port->die->chip->hdev;
+    u64 crc_err_cnt;
+    int ret;
+
+    mutex_lock(&hdev->lock);
+    ret = hccs_query_port_crc_err_cnt(hdev, port, &crc_err_cnt);
+    mutex_unlock(&hdev->lock);
+    if (ret)
+        return ret;
+
+    return sysfs_emit(buf, "%llu\n", crc_err_cnt);
+}
+
+static struct kobj_attribute crc_err_cnt_attr =
+            __ATTR(crc_err_cnt, 0444, crc_err_cnt_show, NULL);
+
+static struct attribute *hccs_port_default_attrs[] = {
+    &hccs_type_attr.attr,
+    &lane_mode_attr.attr,
+    &port_enable_attr.attr,
+    &cur_lane_num_attr.attr,
+    &link_fsm_attr.attr,
+    &lane_mask_attr.attr,
+    &crc_err_cnt_attr.attr,
+    NULL,
+};
+ATTRIBUTE_GROUPS(hccs_port_default);
+
+static const struct kobj_type hccs_port_type = {
+    .sysfs_ops = &hccs_comm_ops,
+    .default_groups = hccs_port_default_groups,
+};
+
+static ssize_t all_linked_on_die_show(struct kobject *kobj,
+                      struct kobj_attribute *attr, char *buf)
+{
+    const struct hccs_die_info *die = kobj_to_die_info(kobj);
+    struct hccs_dev *hdev = die->chip->hdev;
+    u8 all_linked;
+    int ret;
+
+    mutex_lock(&hdev->lock);
+    ret = hccs_get_die_all_link_status(hdev, die, &all_linked);
+    mutex_unlock(&hdev->lock);
+    if (ret)
+        return ret;
+
+    return sysfs_emit(buf, "%u\n", all_linked);
+}
+static struct kobj_attribute all_linked_on_die_attr =
+        __ATTR(all_linked, 0444, all_linked_on_die_show, NULL);
+
+static ssize_t linked_full_lane_on_die_show(struct kobject *kobj,
+                        struct kobj_attribute *attr,
+                        char *buf)
+{
+    const struct hccs_die_info *die = kobj_to_die_info(kobj);
+    struct hccs_dev *hdev = die->chip->hdev;
+    u8 full_lane;
+    int ret;
+
+    mutex_lock(&hdev->lock);
+    ret = hccs_get_die_all_port_lane_status(hdev, die, &full_lane);
+    mutex_unlock(&hdev->lock);
+    if (ret)
+        return ret;
+
+    return sysfs_emit(buf, "%u\n", full_lane);
+}
+static struct kobj_attribute linked_full_lane_on_die_attr =
+    __ATTR(linked_full_lane, 0444, linked_full_lane_on_die_show, NULL);
+
+static ssize_t crc_err_cnt_sum_on_die_show(struct kobject *kobj,
+                       struct kobj_attribute *attr,
+                       char *buf)
+{
+    const struct hccs_die_info *die = kobj_to_die_info(kobj);
+    struct hccs_dev *hdev = die->chip->hdev;
+    u64 total_crc_err_cnt;
+    int ret;
+
+    mutex_lock(&hdev->lock);
+    ret = hccs_get_die_total_crc_err_cnt(hdev, die, &total_crc_err_cnt);
+    mutex_unlock(&hdev->lock);
+    if (ret)
+        return ret;
+
+    return sysfs_emit(buf, "%llu\n", total_crc_err_cnt);
+}
+static struct kobj_attribute crc_err_cnt_sum_on_die_attr =
+    __ATTR(crc_err_cnt, 0444, crc_err_cnt_sum_on_die_show, NULL);
+
+static struct attribute *hccs_die_default_attrs[] = {
+    &all_linked_on_die_attr.attr,
+    &linked_full_lane_on_die_attr.attr,
+    &crc_err_cnt_sum_on_die_attr.attr,
+    NULL,
+};
+ATTRIBUTE_GROUPS(hccs_die_default);
+
+static const struct kobj_type hccs_die_type = {
+    .sysfs_ops = &hccs_comm_ops,
+    .default_groups = hccs_die_default_groups,
+};
+
+static ssize_t all_linked_on_chip_show(struct kobject *kobj,
+                       struct kobj_attribute *attr, char *buf)
+{
+    const struct hccs_chip_info *chip = kobj_to_chip_info(kobj);
+    struct hccs_dev *hdev = chip->hdev;
+    const struct hccs_die_info *die;
+    u8 all_linked = 1;
+    u8 i, tmp;
+    int ret;
+
+    mutex_lock(&hdev->lock);
+    for (i = 0; i < chip->die_num; i++) {
+        die = &chip->dies[i];
+        ret = hccs_get_die_all_link_status(hdev, die, &tmp);
+        if (ret) {
+            mutex_unlock(&hdev->lock);
+            return ret;
+        }
+        if (tmp != all_linked) {
+            all_linked = 0;
+            break;
+        }
+    }
+    mutex_unlock(&hdev->lock);
+
+    return sysfs_emit(buf, "%u\n", all_linked);
+}
+static struct kobj_attribute all_linked_on_chip_attr =
+        __ATTR(all_linked, 0444, all_linked_on_chip_show, NULL);
+
+static ssize_t linked_full_lane_on_chip_show(struct kobject *kobj,
+                         struct kobj_attribute *attr,
+                         char *buf)
+{
+    const struct hccs_chip_info *chip = kobj_to_chip_info(kobj);
+    struct hccs_dev *hdev = chip->hdev;
+    const struct hccs_die_info *die;
+    u8 full_lane = 1;
+    u8 i, tmp;
+    int ret;
+
+    mutex_lock(&hdev->lock);
+    for (i = 0; i < chip->die_num; i++) {
+        die = &chip->dies[i];
+        ret = hccs_get_die_all_port_lane_status(hdev, die, &tmp);
+        if (ret) {
+            mutex_unlock(&hdev->lock);
+            return ret;
+        }
+        if (tmp != full_lane) {
+            full_lane = 0;
+            break;
+        }
+    }
+    mutex_unlock(&hdev->lock);
+
+    return sysfs_emit(buf, "%u\n", full_lane);
+}
+static struct kobj_attribute linked_full_lane_on_chip_attr =
+    __ATTR(linked_full_lane, 0444, linked_full_lane_on_chip_show, NULL);
+
+static ssize_t crc_err_cnt_sum_on_chip_show(struct kobject *kobj,
+                        struct kobj_attribute *attr,
+                        char *buf)
+{
+    const struct hccs_chip_info *chip = kobj_to_chip_info(kobj);
+    u64 crc_err_cnt, total_crc_err_cnt = 0;
+    struct hccs_dev *hdev = chip->hdev;
+    const struct hccs_die_info *die;
+    int ret;
+    u16 i;
+
+    mutex_lock(&hdev->lock);
+    for (i = 0; i < chip->die_num; i++) {
+        die = &chip->dies[i];
+        ret = hccs_get_die_total_crc_err_cnt(hdev, die, &crc_err_cnt);
+        if (ret) {
+            mutex_unlock(&hdev->lock);
+            return ret;
+        }
+
+        total_crc_err_cnt += crc_err_cnt;
+    }
+    mutex_unlock(&hdev->lock);
+
+    return sysfs_emit(buf, "%llu\n", total_crc_err_cnt);
+}
+static struct kobj_attribute crc_err_cnt_sum_on_chip_attr =
+        __ATTR(crc_err_cnt, 0444, crc_err_cnt_sum_on_chip_show, NULL);
+
+static struct attribute *hccs_chip_default_attrs[] = {
+    &all_linked_on_chip_attr.attr,
+    &linked_full_lane_on_chip_attr.attr,
+    &crc_err_cnt_sum_on_chip_attr.attr,
+    NULL,
+};
+ATTRIBUTE_GROUPS(hccs_chip_default);
+
+static const struct kobj_type hccs_chip_type = {
+    .sysfs_ops = &hccs_comm_ops,
+    .default_groups = hccs_chip_default_groups,
+};
+
+static void hccs_remove_die_dir(struct hccs_die_info *die)
+{
+    struct hccs_port_info *port;
+    u8 i;
+
+    for (i = 0; i < die->port_num; i++) {
+        port = &die->ports[i];
+        if (port->dir_created)
+            kobject_put(&port->kobj);
+    }
+
+    kobject_put(&die->kobj);
+}
+
+static void hccs_remove_chip_dir(struct hccs_chip_info *chip)
+{
+    struct hccs_die_info *die;
+    u8 i;
+
+    for (i = 0; i < chip->die_num; i++) {
+        die = &chip->dies[i];
+        if (die->dir_created)
+            hccs_remove_die_dir(die);
+    }
+
+    kobject_put(&chip->kobj);
+}
+
+static void hccs_remove_topo_dirs(struct hccs_dev *hdev)
+{
+    u8 i;
+
+    for (i = 0; i < hdev->chip_num; i++)
+        hccs_remove_chip_dir(&hdev->chips[i]);
+}
+
+static int hccs_create_hccs_dir(struct hccs_dev *hdev,
+                struct hccs_die_info *die,
+                struct hccs_port_info *port)
+{
+    int ret;
+
+    ret = kobject_init_and_add(&port->kobj, &hccs_port_type,
+                   &die->kobj, "hccs%d", port->port_id);
+    if (ret) {
+        kobject_put(&port->kobj);
+        return ret;
+    }
+
+    return 0;
+}
+
+static int hccs_create_die_dir(struct hccs_dev *hdev,
+                   struct hccs_chip_info *chip,
+                   struct hccs_die_info *die)
+{
+    struct hccs_port_info *port;
+    int ret;
+    u16 i;
+
+    ret = kobject_init_and_add(&die->kobj, &hccs_die_type,
+                   &chip->kobj, "die%d", die->die_id);
+    if (ret) {
+        kobject_put(&die->kobj);
+        return ret;
+    }
+
+    for (i = 0; i < die->port_num; i++) {
+        port = &die->ports[i];
+        ret = hccs_create_hccs_dir(hdev, die, port);
+        if (ret) {
+            dev_err(hdev->dev, "create hccs%d dir failed.\n",
+                port->port_id);
+            goto err;
+        }
+        port->dir_created = true;
+    }
+
+    return 0;
+err:
+    hccs_remove_die_dir(die);
+
+    return ret;
+}
+
+static int hccs_create_chip_dir(struct hccs_dev *hdev,
+                struct hccs_chip_info *chip)
+{
+    struct hccs_die_info *die;
+    int ret;
+    u16 id;
+
+    ret = kobject_init_and_add(&chip->kobj, &hccs_chip_type,
+                   &hdev->dev->kobj, "chip%d", chip->chip_id);
+    if (ret) {
+        kobject_put(&chip->kobj);
+        return ret;
+    }
+
+    for (id = 0; id < chip->die_num; id++) {
+        die = &chip->dies[id];
+        ret = hccs_create_die_dir(hdev, chip, die);
+        if (ret)
+            goto err;
+        die->dir_created = true;
+    }
+
+    return 0;
+err:
+    hccs_remove_chip_dir(chip);
+
+    return ret;
+}
+
+static int hccs_create_topo_dirs(struct hccs_dev *hdev)
+{
+    struct hccs_chip_info *chip;
+    u8 id, k;
+    int ret;
+
+    for (id = 0; id < hdev->chip_num; id++) {
+        chip = &hdev->chips[id];
+        ret = hccs_create_chip_dir(hdev, chip);
+        if (ret) {
+            dev_err(hdev->dev, "init chip%d dir failed!\n", id);
+            goto err;
+        }
+    }
+
+    return 0;
+err:
+    for (k = 0; k < id; k++)
+        hccs_remove_chip_dir(&hdev->chips[k]);
+
+    return ret;
+}
+
+static int hccs_probe(struct platform_device *pdev)
+{
+    struct acpi_device *acpi_dev;
+    struct hccs_dev *hdev;
+    int rc;
+
+    if (acpi_disabled) {
+        dev_err(&pdev->dev, "acpi is disabled.\n");
+        return -ENODEV;
+    }
+    acpi_dev = ACPI_COMPANION(&pdev->dev);
+    if (!acpi_dev)
+        return -ENODEV;
+
+    hdev = devm_kzalloc(&pdev->dev, sizeof(*hdev), GFP_KERNEL);
+    if (!hdev)
+        return -ENOMEM;
+    hdev->acpi_dev = acpi_dev;
+    hdev->dev = &pdev->dev;
+    platform_set_drvdata(pdev, hdev);
+
+    mutex_init(&hdev->lock);
+    rc = hccs_get_pcc_chan_id(hdev);
+    if (rc)
+        return rc;
+    rc = hccs_register_pcc_channel(hdev);
+    if (rc)
+        return rc;
+
+    rc = hccs_get_dev_caps(hdev);
+    if (rc)
+        goto unregister_pcc_chan;
+
+    rc = hccs_get_hw_info(hdev);
+    if (rc)
+        goto unregister_pcc_chan;
+
+    rc = hccs_create_topo_dirs(hdev);
+    if (rc)
+        goto unregister_pcc_chan;
+
+    return 0;
+
+unregister_pcc_chan:
+    hccs_unregister_pcc_channel(hdev);
+
+    return rc;
+}
+
+static int hccs_remove(struct platform_device *pdev)
+{
+    struct hccs_dev *hdev = platform_get_drvdata(pdev);
+
+    hccs_remove_topo_dirs(hdev);
+    hccs_unregister_pcc_channel(hdev);
+
+    return 0;
+}
+
+static const struct acpi_device_id hccs_acpi_match[] = {
+    { "HISI04B1", },
+};
It is better to add MODULE_DEVICE_TABLE to autoload the driver.
I tested that this macro doesn't help to autoload driver if select this driver as 'M'.
How does it work?
I know how it works. It does automatically load the driver even if select 'M'.
will add it in v4.

Best regards,
Huisong

[snip]
.