/* SPDX-License-Identifier: GPL-2.0+ */
/* Copyright IBM Corp 2019 */

#ifndef OCC_COMMON_H
#define OCC_COMMON_H

#include <linux/hwmon-sysfs.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>

struct device;

#define OCC_RESP_DATA_BYTES             4089

/*
 * Same response format for all OCC versions.
 * Allocate the largest possible response.
 */
struct occ_response {
        u8 seq_no;
        u8 cmd_type;
        u8 return_status;
        __be16 data_length;
        u8 data[OCC_RESP_DATA_BYTES];
        __be16 checksum;
} __packed;

struct occ_sensor_data_block_header {
        u8 eye_catcher[4];
        u8 reserved;
        u8 sensor_format;
        u8 sensor_length;
        u8 num_sensors;
} __packed;

struct occ_sensor_data_block {
        struct occ_sensor_data_block_header header;
        u32 data;
} __packed;

struct occ_poll_response_header {
        u8 status;
        u8 ext_status;
        u8 occs_present;
        u8 config_data;
        u8 occ_state;
        u8 mode;
        u8 ips_status;
        u8 error_log_id;
        __be32 error_log_start_address;
        __be16 error_log_length;
        u16 reserved;
        u8 occ_code_level[16];
        u8 eye_catcher[6];
        u8 num_sensor_data_blocks;
        u8 sensor_data_block_header_version;
} __packed;

struct occ_poll_response {
        struct occ_poll_response_header header;
        struct occ_sensor_data_block block;
} __packed;

struct occ_sensor {
        u8 num_sensors;
        u8 version;
        void *data;     /* pointer to sensor data start within response */
};

/*
 * OCC only provides one sensor data block of each type, but any number of
 * sensors within that block.
 */
struct occ_sensors {
        struct occ_sensor temp;
        struct occ_sensor freq;
        struct occ_sensor power;
        struct occ_sensor caps;
        struct occ_sensor extended;
};

/*
 * Use our own attribute struct so we can dynamically allocate space for the
 * name.
 */
struct occ_attribute {
        char name[32];
        struct sensor_device_attribute_2 sensor;
};

struct occ {
        struct device *bus_dev;

        struct occ_response resp;
        struct occ_sensors sensors;

        int powr_sample_time_us;        /* average power sample time */
        u8 poll_cmd_data;               /* to perform OCC poll command */
        int (*send_cmd)(struct occ *occ, u8 *cmd, size_t len, void *resp,
                        size_t resp_len);

        unsigned long next_update;
        struct mutex lock;              /* lock OCC access */

        struct device *hwmon;
        struct occ_attribute *attrs;
        struct attribute_group group;
        const struct attribute_group *groups[2];

        bool active;
        int error;                      /* final transfer error after retry */
        int last_error;                 /* latest transfer error */
        unsigned int error_count;       /* number of xfr errors observed */
        unsigned long last_safe;        /* time OCC entered "safe" state */

        /*
         * Store the previous state data for comparison in order to notify
         * sysfs readers of state changes.
         */
        int prev_error;
        u8 prev_stat;
        u8 prev_ext_stat;
        u8 prev_occs_present;
        u8 prev_ips_status;
        u8 prev_mode;
};

int occ_active(struct occ *occ, bool active);
int occ_setup(struct occ *occ);
int occ_setup_sysfs(struct occ *occ);
void occ_shutdown(struct occ *occ);
void occ_shutdown_sysfs(struct occ *occ);
void occ_sysfs_poll_done(struct occ *occ);
int occ_update_response(struct occ *occ);

#endif /* OCC_COMMON_H */