The CPLD and FPGA driver framework module complies with s3ip sysfs specification (sonic-net#12891)

Why I did it
Provide CPLD and FPGA driver framework that complies with s3ip sysfs specification

How I did it
1、 The framework module provides register and unregister interface and implementation.
2、 The framework will help you create the sysfs node

How to verify it
A demo driver base on this framework will display the sysfs node wich conform to the s3ip sysfs specification

Author: tianshangfei

platform/s3ip-sysfs/s3ip_sysfs_frame/cpld_sysfs.c

@@ -0,0 +1,365 @@
+/*
+ * cpld_sysfs.c
+ *
+ * This module create cpld kobjects and attributes in /sys/s3ip/cpld
+ *
+ * History
+ *  [Version]                [Date]                    [Description]
+ *   *  v1.0                2021-08-31                  S3IP sysfs
+ */
+
+#include <linux/slab.h>
+
+#include "switch.h"
+#include "cpld_sysfs.h"
+
+static int g_cpld_loglevel = 0;
+
+#define CPLD_INFO(fmt, args...) do {                                        \
+    if (g_cpld_loglevel & INFO) { \
+        printk(KERN_INFO "[CPLD_SYSFS][func:%s line:%d]\n"fmt, __func__, __LINE__, ## args); \
+    } \
+} while (0)
+
+#define CPLD_ERR(fmt, args...) do {                                        \
+    if (g_cpld_loglevel & ERR) { \
+        printk(KERN_ERR "[CPLD_SYSFS][func:%s line:%d]\n"fmt, __func__, __LINE__, ## args); \
+    } \
+} while (0)
+
+#define CPLD_DBG(fmt, args...) do {                                        \
+    if (g_cpld_loglevel & DBG) { \
+        printk(KERN_DEBUG "[CPLD_SYSFS][func:%s line:%d]\n"fmt, __func__, __LINE__, ## args); \
+    } \
+} while (0)
+
+struct cpld_obj_s {
+    struct switch_obj *obj;
+};
+
+struct cpld_s {
+    unsigned int cpld_number;
+    struct cpld_obj_s *cpld;
+};
+
+static struct cpld_s g_cpld;
+static struct switch_obj *g_cpld_obj = NULL;
+static struct s3ip_sysfs_cpld_drivers_s *g_cpld_drv = NULL;
+
+static ssize_t cpld_number_show(struct switch_obj *obj, struct switch_attribute *attr, char *buf)
+{
+    return (ssize_t)snprintf(buf, PAGE_SIZE, "%u\n", g_cpld.cpld_number);
+}
+
+static ssize_t cpld_alias_show(struct switch_obj *obj, struct switch_attribute *attr, char *buf)
+{
+    unsigned int cpld_index;
+    int ret;
+
+    check_p(g_cpld_drv);
+    check_p(g_cpld_drv->get_main_board_cpld_alias);
+
+    cpld_index = obj->index;
+    CPLD_DBG("cpld index: %u\n", cpld_index);
+    ret = g_cpld_drv->get_main_board_cpld_alias(cpld_index, buf, PAGE_SIZE);
+    if (ret < 0) {
+        CPLD_ERR("get cpld%u alias failed, ret: %d\n", cpld_index, ret);
+        return (ssize_t)snprintf(buf, PAGE_SIZE, "%s\n", SYSFS_DEV_ERROR);
+    }
+    return ret;
+}
+
+static ssize_t cpld_type_show(struct switch_obj *obj, struct switch_attribute *attr, char *buf)
+{
+    unsigned int cpld_index;
+    int ret;
+
+    check_p(g_cpld_drv);
+    check_p(g_cpld_drv->get_main_board_cpld_type);
+
+    cpld_index = obj->index;
+    CPLD_DBG("cpld index: %u\n", cpld_index);
+    ret = g_cpld_drv->get_main_board_cpld_type(cpld_index, buf, PAGE_SIZE);
+    if (ret < 0) {
+        CPLD_ERR("get cpld%u type failed, ret: %d\n", cpld_index, ret);
+        return (ssize_t)snprintf(buf, PAGE_SIZE, "%s\n", SYSFS_DEV_ERROR);
+    }
+    return ret;
+}
+
+static ssize_t cpld_fw_version_show(struct switch_obj *obj, struct switch_attribute *attr, char *buf)
+{
+    unsigned int cpld_index;
+    int ret;
+
+    check_p(g_cpld_drv);
+    check_p(g_cpld_drv->get_main_board_cpld_firmware_version);
+
+    cpld_index = obj->index;
+    CPLD_DBG("cpld index: %u\n", cpld_index);
+    ret = g_cpld_drv->get_main_board_cpld_firmware_version(cpld_index, buf, PAGE_SIZE);
+    if (ret < 0) {
+        CPLD_ERR("get cpld%u firmware version failed, ret: %d\n", cpld_index, ret);
+        return (ssize_t)snprintf(buf, PAGE_SIZE, "%s\n", SYSFS_DEV_ERROR);
+    }
+    return ret;
+}
+
+static ssize_t cpld_board_version_show(struct switch_obj *obj, struct switch_attribute *attr, char *buf)
+{
+    unsigned int cpld_index;
+    int ret;
+
+    check_p(g_cpld_drv);
+    check_p(g_cpld_drv->get_main_board_cpld_board_version);
+
+    cpld_index = obj->index;
+    CPLD_DBG("cpld index: %u\n", cpld_index);
+    ret = g_cpld_drv->get_main_board_cpld_board_version(cpld_index, buf, PAGE_SIZE);
+    if (ret < 0) {
+        CPLD_ERR("get cpld%u board version failed, ret: %d\n", cpld_index, ret);
+        return (ssize_t)snprintf(buf, PAGE_SIZE, "%s\n", SYSFS_DEV_ERROR);
+    }
+    return ret;
+}
+
+static ssize_t cpld_test_reg_show(struct switch_obj *obj, struct switch_attribute *attr, char *buf)
+{
+    unsigned int cpld_index;
+    int ret;
+
+    check_p(g_cpld_drv);
+    check_p(g_cpld_drv->get_main_board_cpld_test_reg);
+
+    cpld_index = obj->index;
+    CPLD_DBG("cpld index: %u\n", cpld_index);
+    ret = g_cpld_drv->get_main_board_cpld_test_reg(cpld_index, buf, PAGE_SIZE);
+    if (ret < 0) {
+        CPLD_ERR("get cpld%u test register failed, ret: %d\n", cpld_index, ret);
+        return (ssize_t)snprintf(buf, PAGE_SIZE, "%s\n", SYSFS_DEV_ERROR);
+    }
+    return ret;
+}
+
+static ssize_t cpld_test_reg_store(struct switch_obj *obj, struct switch_attribute *attr,
+                   const char* buf, size_t count)
+{
+    unsigned int cpld_index, value;
+    int ret;
+
+    check_p(g_cpld_drv);
+    check_p(g_cpld_drv->set_main_board_cpld_test_reg);
+
+    cpld_index = obj->index;
+    sscanf(buf, "0x%x", &value);
+    ret = g_cpld_drv->set_main_board_cpld_test_reg(cpld_index, value);
+    if (ret < 0) {
+        CPLD_ERR("set cpld%u test reg failed, value:0x%x, ret: %d.\n", cpld_index, value, ret);
+        return -EIO;
+    }
+    CPLD_DBG("set cpld%u test reg success, value: 0x%x.\n", cpld_index, value);
+    return count;
+}
+
+/************************************cpld dir and attrs*******************************************/
+static struct switch_attribute cpld_number_att = __ATTR(number, S_IRUGO, cpld_number_show, NULL);
+
+static struct attribute *cpld_dir_attrs[] = {
+    &cpld_number_att.attr,
+    NULL,
+};
+
+static struct attribute_group cpld_root_attr_group = {
+    .attrs = cpld_dir_attrs,
+};
+
+/*******************************cpld[1-n] dir and attrs*******************************************/
+static struct switch_attribute cpld_alias_attr = __ATTR(alias, S_IRUGO, cpld_alias_show, NULL);
+static struct switch_attribute cpld_type_attr = __ATTR(type, S_IRUGO, cpld_type_show, NULL);
+static struct switch_attribute cpld_fw_version_attr = __ATTR(firmware_version, S_IRUGO, cpld_fw_version_show, NULL);
+static struct switch_attribute cpld_board_version_attr = __ATTR(board_version, S_IRUGO, cpld_board_version_show, NULL);
+static struct switch_attribute cpld_test_reg_attr = __ATTR(reg_test, S_IRUGO | S_IWUSR, cpld_test_reg_show, cpld_test_reg_store);
+
+static struct attribute *cpld_attrs[] = {
+    &cpld_alias_attr.attr,
+    &cpld_type_attr.attr,
+    &cpld_fw_version_attr.attr,
+    &cpld_board_version_attr.attr,
+    &cpld_test_reg_attr.attr,
+    NULL,
+};
+
+static struct attribute_group cpld_attr_group = {
+    .attrs = cpld_attrs,
+};
+
+static int cpld_sub_single_remove_kobj_and_attrs(unsigned int index)
+{
+    struct cpld_obj_s *curr_cpld;
+
+    curr_cpld = &g_cpld.cpld[index - 1];
+    if (curr_cpld->obj) {
+        sysfs_remove_group(&curr_cpld->obj->kobj, &cpld_attr_group);
+        switch_kobject_delete(&curr_cpld->obj);
+        CPLD_DBG("delete cpld%u dir and attrs success.\n", index);
+    }
+
+    return 0;
+}
+
+static int cpld_sub_single_create_kobj_and_attrs(struct kobject *parent, unsigned int index)
+{
+    char name[8];
+    struct cpld_obj_s *curr_cpld;
+
+    curr_cpld = &g_cpld.cpld[index - 1];
+    memset(name, 0, sizeof(name));
+    snprintf(name, sizeof(name), "cpld%u", index);
+    curr_cpld->obj = switch_kobject_create(name, parent);
+    if (!curr_cpld->obj) {
+        CPLD_ERR("create %s object error!\n", name);
+        return -EBADRQC;
+    }
+    curr_cpld->obj->index = index;
+    if (sysfs_create_group(&curr_cpld->obj->kobj, &cpld_attr_group) != 0) {
+        CPLD_ERR("create %s attrs error.\n", name);
+        switch_kobject_delete(&curr_cpld->obj);
+        return -EBADRQC;
+    }
+    CPLD_DBG("create %s dir and attrs success.\n", name);
+    return 0;
+}
+
+static int cpld_sub_create_kobj_and_attrs(struct kobject *parent, int cpld_num)
+{
+    unsigned int cpld_index, i;
+
+    g_cpld.cpld = kzalloc(sizeof(struct cpld_obj_s) * cpld_num, GFP_KERNEL);
+    if (!g_cpld.cpld) {
+        CPLD_ERR("kzalloc g_cpld.cpld error, cpld number = %d.\n", cpld_num);
+        return -ENOMEM;
+    }
+
+    for(cpld_index = 1; cpld_index <= cpld_num; cpld_index++) {
+        if(cpld_sub_single_create_kobj_and_attrs(parent, cpld_index) != 0) {
+            goto error;
+        }
+    }
+    return 0;
+error:
+    for(i = cpld_index; i > 0; i--) {
+        cpld_sub_single_remove_kobj_and_attrs(i);
+    }
+    kfree(g_cpld.cpld);
+    g_cpld.cpld = NULL;
+    return -EBADRQC;
+}
+
+/* create cpld[1-n] directory and attributes*/
+static int cpld_sub_create(void)
+{
+    int ret;
+
+    ret = cpld_sub_create_kobj_and_attrs(&g_cpld_obj->kobj, g_cpld.cpld_number);
+    return ret;
+}
+
+/* delete cpld[1-n] directory and attributes*/
+static void cpld_sub_remove(void)
+{
+    unsigned int cpld_index;
+
+    if (g_cpld.cpld) {
+        for (cpld_index = g_cpld.cpld_number; cpld_index > 0; cpld_index--) {
+            cpld_sub_single_remove_kobj_and_attrs(cpld_index);
+        }
+        kfree(g_cpld.cpld);
+        g_cpld.cpld = NULL;
+    }
+    g_cpld.cpld_number = 0;
+    return;
+}
+
+/* create cpld directory and number attributes */
+static int cpld_root_create(void)
+{
+    g_cpld_obj = switch_kobject_create("cpld", NULL);
+    if (!g_cpld_obj) {
+        CPLD_ERR("switch_kobject_create cpld error!\n");
+        return -ENOMEM;
+    }
+
+    if (sysfs_create_group(&g_cpld_obj->kobj, &cpld_root_attr_group) != 0) {
+        switch_kobject_delete(&g_cpld_obj);
+        CPLD_ERR("create cpld dir attrs error!\n");
+        return -EBADRQC;
+    }
+    return 0;
+}
+
+/* delete cpld directory and number attributes */
+static void cpld_root_remove(void)
+{
+    if (g_cpld_obj) {
+        sysfs_remove_group(&g_cpld_obj->kobj, &cpld_root_attr_group);
+        switch_kobject_delete(&g_cpld_obj);
+    }
+
+    return;
+}
+
+int s3ip_sysfs_cpld_drivers_register(struct s3ip_sysfs_cpld_drivers_s *drv)
+{
+    int ret, cpld_num;
+
+    CPLD_INFO("s3ip_sysfs_cpld_drivers_register...\n");
+    if (g_cpld_drv) {
+        CPLD_ERR("g_cpld_drv is not NULL, can't register\n");
+        return -EPERM;
+    }
+
+    check_p(drv);
+    check_p(drv->get_main_board_cpld_number);
+    g_cpld_drv = drv;
+
+    cpld_num = g_cpld_drv->get_main_board_cpld_number();
+    if (cpld_num <= 0) {
+        CPLD_ERR("cpld number: %d, don't need to create cpld dirs and attrs.\n", cpld_num);
+        g_cpld_drv = NULL;
+        return -EINVAL;
+    }
+
+    memset(&g_cpld, 0, sizeof(struct cpld_s));
+    g_cpld.cpld_number = cpld_num;
+    ret = cpld_root_create();
+    if (ret < 0) {
+        CPLD_ERR("create cpld root dir and attrs failed, ret: %d\n", ret);
+        g_cpld_drv = NULL;
+        return ret;
+    }
+    ret = cpld_sub_create();
+    if (ret < 0) {
+        CPLD_ERR("create cpld sub dir and attrs failed, ret: %d\n", ret);
+        cpld_root_remove();
+        g_cpld_drv = NULL;
+        return ret;
+    }
+    CPLD_INFO("s3ip_sysfs_cpld_drivers_register success\n");
+    return 0;
+}
+
+void s3ip_sysfs_cpld_drivers_unregister(void)
+{
+    if (g_cpld_drv) {
+        cpld_sub_remove();
+        cpld_root_remove();
+        g_cpld_drv = NULL;
+        CPLD_DBG("s3ip_sysfs_cpld_drivers_unregister success.\n");
+    }
+    return;
+}
+
+EXPORT_SYMBOL(s3ip_sysfs_cpld_drivers_register);
+EXPORT_SYMBOL(s3ip_sysfs_cpld_drivers_unregister);
+module_param(g_cpld_loglevel, int, 0644);
+MODULE_PARM_DESC(g_cpld_loglevel, "the log level(info=0x1, err=0x2, dbg=0x4).\n");