From: "Edward A. James" <eajames@xxxxxxxxxx> Add core support for polling the OCC for it's sensor data and parsing that data into sensor-specific information. Signed-off-by: Edward A. James <eajames@xxxxxxxxxx> Signed-off-by: Andrew Jeffery <andrew@xxxxxxxx> --- Documentation/hwmon/occ | 40 ++++ MAINTAINERS | 7 + drivers/hwmon/Kconfig | 2 + drivers/hwmon/Makefile | 1 + drivers/hwmon/occ/Kconfig | 15 ++ drivers/hwmon/occ/Makefile | 1 + drivers/hwmon/occ/occ.c | 522 +++++++++++++++++++++++++++++++++++++++++++++ drivers/hwmon/occ/occ.h | 81 +++++++ drivers/hwmon/occ/scom.h | 47 ++++ 9 files changed, 716 insertions(+) create mode 100644 Documentation/hwmon/occ create mode 100644 drivers/hwmon/occ/Kconfig create mode 100644 drivers/hwmon/occ/Makefile create mode 100644 drivers/hwmon/occ/occ.c create mode 100644 drivers/hwmon/occ/occ.h create mode 100644 drivers/hwmon/occ/scom.h diff --git a/Documentation/hwmon/occ b/Documentation/hwmon/occ new file mode 100644 index 0000000..79d1642 --- /dev/null +++ b/Documentation/hwmon/occ @@ -0,0 +1,40 @@ +Kernel driver occ +================= + +Supported chips: + * ASPEED AST2400 + * ASPEED AST2500 + +Please note that the chip must be connected to a POWER8 or POWER9 processor +(see the BMC - Host Communications section). + +Author: Eddie James <eajames@xxxxxxxxxx> + +Description +----------- + +This driver implements support for the OCC (On-Chip Controller) on the IBM +POWER8 and POWER9 processors, from a BMC (Baseboard Management Controller). The +OCC is an embedded processor that provides real time power and thermal +monitoring. + +This driver provides an interface on a BMC to poll OCC sensor data, set user +power caps, and perform some basic OCC error handling. + +Currently, all versions of the OCC support four types of sensor data: power, +temperature, frequency, and "caps," which indicate limits and thresholds used +internally on the OCC. + +BMC - Host Communications +------------------------- + +For the POWER8 application, the BMC can communicate with the P8 over I2C bus. +However, to access the OCC register space, any data transfer must use a SCOM +operation. SCOM is a procedure to initiate a data transfer, typically of 8 +bytes. SCOMs consist of writing a 32-bit command register and then +reading/writing two 32-bit data registers. This driver implements these +SCOM operations over I2C bus in order to communicate with the OCC. + +For the POWER9 application, the BMC can communicate with the P9 over FSI bus +and SBE engine. Once again, SCOM operations are required. This driver will +implement SCOM ops over FSI/SBE. This will require the FSI driver. diff --git a/MAINTAINERS b/MAINTAINERS index 5f0420a..f5d4195 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9112,6 +9112,13 @@ T: git git://linuxtv.org/media_tree.git S: Maintained F: drivers/media/i2c/ov7670.c +ON-CHIP CONTROLLER HWMON DRIVER +M: Eddie James <eajames@xxxxxxxxxx> +L: linux-hwmon@xxxxxxxxxxxxxxx +S: Maintained +F: Documentation/hwmon/occ +F: drivers/hwmon/occ/ + ONENAND FLASH DRIVER M: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> L: linux-mtd@xxxxxxxxxxxxxxxxxxx diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 190d270..e80ca81 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1240,6 +1240,8 @@ config SENSORS_NSA320 This driver can also be built as a module. If so, the module will be called nsa320-hwmon. +source drivers/hwmon/occ/Kconfig + config SENSORS_PCF8591 tristate "Philips PCF8591 ADC/DAC" depends on I2C diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index d2cb7e8..c7ec5d4 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -169,6 +169,7 @@ obj-$(CONFIG_SENSORS_WM831X) += wm831x-hwmon.o obj-$(CONFIG_SENSORS_WM8350) += wm8350-hwmon.o obj-$(CONFIG_SENSORS_XGENE) += xgene-hwmon.o +obj-$(CONFIG_SENSORS_PPC_OCC) += occ/ obj-$(CONFIG_PMBUS) += pmbus/ ccflags-$(CONFIG_HWMON_DEBUG_CHIP) := -DDEBUG diff --git a/drivers/hwmon/occ/Kconfig b/drivers/hwmon/occ/Kconfig new file mode 100644 index 0000000..cdb64a7 --- /dev/null +++ b/drivers/hwmon/occ/Kconfig @@ -0,0 +1,15 @@ +# +# On Chip Controller configuration +# + +menuconfig SENSORS_PPC_OCC + bool "PPC On-Chip Controller" + help + If you say yes here you get support to monitor Power CPU + sensors via the On-Chip Controller (OCC). + + Generally this is used by management controllers such as a BMC + on an OpenPower system. + + This driver can also be built as a module. If so, the module + will be called occ. diff --git a/drivers/hwmon/occ/Makefile b/drivers/hwmon/occ/Makefile new file mode 100644 index 0000000..93cb52f --- /dev/null +++ b/drivers/hwmon/occ/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_SENSORS_PPC_OCC) += occ.o diff --git a/drivers/hwmon/occ/occ.c b/drivers/hwmon/occ/occ.c new file mode 100644 index 0000000..3089762 --- /dev/null +++ b/drivers/hwmon/occ/occ.c @@ -0,0 +1,522 @@ +/* + * occ.c - OCC hwmon driver + * + * This file contains the methods and data structures for the OCC hwmon driver. + * + * Copyright 2016 IBM Corp. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <asm/unaligned.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include "occ.h" + +#define OCC_DATA_MAX 4096 +#define OCC_BMC_TIMEOUT_MS 20000 + +/* To generate attn to OCC */ +#define ATTN_DATA 0x0006B035 + +/* For BMC to read/write SRAM */ +#define OCB_ADDRESS 0x0006B070 +#define OCB_DATA 0x0006B075 +#define OCB_STATUS_CONTROL_AND 0x0006B072 +#define OCB_STATUS_CONTROL_OR 0x0006B073 + +/* To init OCB */ +#define OCB_AND_INIT0 0xFBFFFFFF +#define OCB_AND_INIT1 0xFFFFFFFF +#define OCB_OR_INIT0 0x08000000 +#define OCB_OR_INIT1 0x00000000 + +/* To generate attention on OCC */ +#define ATTN0 0x01010000 +#define ATTN1 0x00000000 + +/* OCC return status */ +#define RESP_RETURN_CMD_IN_PRG 0xFF +#define RESP_RETURN_SUCCESS 0 +#define RESP_RETURN_CMD_INVAL 0x11 +#define RESP_RETURN_CMD_LEN 0x12 +#define RESP_RETURN_DATA_INVAL 0x13 +#define RESP_RETURN_CHKSUM 0x14 +#define RESP_RETURN_OCC_ERR 0x15 +#define RESP_RETURN_STATE 0x16 + +/* time interval to retry on "command in progress" return status */ +#define CMD_IN_PRG_INT_MS 100 +#define CMD_IN_PRG_RETRIES (OCC_BMC_TIMEOUT_MS / CMD_IN_PRG_INT_MS) + +/* OCC command definitions */ +#define OCC_POLL 0 +#define OCC_SET_USER_POWR_CAP 0x22 + +/* OCC poll command data */ +#define OCC_POLL_STAT_SENSOR 0x10 + +/* OCC response data offsets */ +#define RESP_RETURN_STATUS 2 +#define RESP_DATA_LENGTH 3 +#define RESP_HEADER_OFFSET 5 +#define SENSOR_STR_OFFSET 37 +#define SENSOR_BLOCK_NUM_OFFSET 43 +#define SENSOR_BLOCK_OFFSET 45 + +/* occ_poll_header + * structure to match the raw occ poll response data + */ +struct occ_poll_header { + u8 status; + u8 ext_status; + u8 occs_present; + u8 config; + u8 occ_state; + u8 mode; + u8 ips_status; + u8 error_log_id; + u32 error_log_addr_start; + u16 error_log_length; + u8 reserved2; + u8 reserved3; + u8 occ_code_level[16]; + u8 sensor_eye_catcher[6]; + u8 sensor_block_num; + u8 sensor_data_version; +} __attribute__((packed, aligned(4))); + +struct occ_response { + struct occ_poll_header header; + struct occ_blocks data; +}; + +struct occ { + struct device *dev; + void *bus; + struct occ_bus_ops bus_ops; + struct occ_ops ops; + struct occ_config config; + unsigned long update_interval; + unsigned long last_updated; + struct mutex update_lock; + struct occ_response response; + bool valid; +}; + +static void deinit_occ_resp_buf(struct occ_response *resp) +{ + int i; + + if (!resp) + return; + + if (!resp->data.blocks) + return; + + for (i = 0; i < resp->header.sensor_block_num; ++i) + kfree(resp->data.blocks[i].sensors); + + kfree(resp->data.blocks); + + memset(resp, 0, sizeof(struct occ_response)); + + for (i = 0; i < MAX_OCC_SENSOR_TYPE; ++i) + resp->data.sensor_block_id[i] = -1; +} + +static void *occ_get_sensor_by_type(struct occ_response *resp, + enum sensor_type t) +{ + if (!resp->data.blocks) + return NULL; + + if (resp->data.sensor_block_id[t] == -1) + return NULL; + + return resp->data.blocks[resp->data.sensor_block_id[t]].sensors; +} + +static int occ_check_sensor(struct occ *driver, u8 sensor_length, + u8 sensor_num, enum sensor_type t, int block) +{ + void *sensor; + int type_block_id; + struct occ_response *resp = &driver->response; + + sensor = occ_get_sensor_by_type(resp, t); + + /* empty sensor block, release older sensor data */ + if (sensor_num == 0 || sensor_length == 0) { + kfree(sensor); + dev_err(driver->dev, "no sensor blocks available\n"); + return -ENODATA; + } + + type_block_id = resp->data.sensor_block_id[t]; + if (!sensor || sensor_num != + resp->data.blocks[type_block_id].header.sensor_num) { + kfree(sensor); + resp->data.blocks[block].sensors = + driver->ops.alloc_sensor(t, sensor_num); + if (!resp->data.blocks[block].sensors) + return -ENOMEM; + } + + return 0; +} + +static int parse_occ_response(struct occ *driver, u8 *data, + struct occ_response *resp) +{ + int b; + int s; + int rc; + int offset = SENSOR_BLOCK_OFFSET; + int sensor_type; + u8 sensor_block_num; + char sensor_type_string[5] = { 0 }; + struct sensor_data_block_header *block; + struct device *dev = driver->dev; + + /* check if the data is valid */ + if (strncmp(&data[SENSOR_STR_OFFSET], "SENSOR", 6) != 0) { + dev_err(dev, "no SENSOR string in response\n"); + rc = -ENODATA; + goto err; + } + + sensor_block_num = data[SENSOR_BLOCK_NUM_OFFSET]; + if (sensor_block_num == 0) { + dev_err(dev, "no sensor blocks available\n"); + rc = -ENODATA; + goto err; + } + + /* if number of sensor block has changed, re-malloc */ + if (sensor_block_num != resp->header.sensor_block_num) { + deinit_occ_resp_buf(resp); + resp->data.blocks = kcalloc(sensor_block_num, + sizeof(struct sensor_data_block), + GFP_KERNEL); + if (!resp->data.blocks) + return -ENOMEM; + } + + memcpy(&resp->header, &data[RESP_HEADER_OFFSET], + sizeof(struct occ_poll_header)); + resp->header.error_log_addr_start = + be32_to_cpu(resp->header.error_log_addr_start); + resp->header.error_log_length = + be16_to_cpu(resp->header.error_log_length); + + dev_dbg(dev, "Reading %d sensor blocks\n", + resp->header.sensor_block_num); + for (b = 0; b < sensor_block_num; b++) { + block = (struct sensor_data_block_header *)&data[offset]; + /* copy to a null terminated string */ + strncpy(sensor_type_string, block->sensor_type, 4); + offset += 8; + + dev_dbg(dev, "sensor block[%d]: type: %s, sensor_num: %d\n", b, + sensor_type_string, block->sensor_num); + + if (strncmp(block->sensor_type, "FREQ", 4) == 0) + sensor_type = FREQ; + else if (strncmp(block->sensor_type, "TEMP", 4) == 0) + sensor_type = TEMP; + else if (strncmp(block->sensor_type, "POWR", 4) == 0) + sensor_type = POWER; + else if (strncmp(block->sensor_type, "CAPS", 4) == 0) + sensor_type = CAPS; + else { + dev_err(dev, "sensor type not supported %s\n", + sensor_type_string); + continue; + } + + rc = occ_check_sensor(driver, block->sensor_length, + block->sensor_num, sensor_type, b); + if (rc == -ENOMEM) + goto err; + else if (rc) + continue; + + resp->data.sensor_block_id[sensor_type] = b; + for (s = 0; s < block->sensor_num; s++) { + driver->ops.parse_sensor(data, + resp->data.blocks[b].sensors, + sensor_type, offset, s); + offset += block->sensor_length; + } + + /* copy block data over to response pointer */ + resp->data.blocks[b].header = *block; + } + + return 0; +err: + deinit_occ_resp_buf(resp); + return rc; +} + +static u8 occ_send_cmd(struct occ *driver, u8 seq, u8 type, u16 length, + const u8 *data, u8 *resp) +{ + u32 cmd1, cmd2; + u16 checksum = 0; + u16 length_le = cpu_to_le16(length); + bool retry = 0; + int i, rc, tries = 0; + + cmd1 = (seq << 24) | (type << 16) | length_le; + memcpy(&cmd2, data, length); + cmd2 <<= ((4 - length) * 8); + + /* checksum: sum of every bytes of cmd1, cmd2 */ + for (i = 0; i < 4; i++) { + checksum += (cmd1 >> (i * 8)) & 0xFF; + checksum += (cmd2 >> (i * 8)) & 0xFF; + } + + cmd2 |= checksum << ((2 - length) * 8); + + /* Init OCB */ + rc = driver->bus_ops.putscom(driver->bus, OCB_STATUS_CONTROL_OR, + OCB_OR_INIT0, OCB_OR_INIT1); + if (rc) + goto err; + + rc = driver->bus_ops.putscom(driver->bus, OCB_STATUS_CONTROL_AND, + OCB_AND_INIT0, OCB_AND_INIT1); + if (rc) + goto err; + + /* Send command, 2nd half of the 64-bit addr is unused (write 0) */ + rc = driver->bus_ops.putscom(driver->bus, OCB_ADDRESS, + driver->config.command_addr, 0); + if (rc) + goto err; + + rc = driver->bus_ops.putscom(driver->bus, OCB_DATA, cmd1, cmd2); + if (rc) + goto err; + + /* Trigger attention */ + rc = driver->bus_ops.putscom(driver->bus, ATTN_DATA, ATTN0, ATTN1); + if (rc) + goto err; + + /* Get response data */ + rc = driver->bus_ops.putscom(driver->bus, OCB_ADDRESS, + driver->config.response_addr, 0); + if (rc) + goto err; + + do { + if (retry) { + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(msecs_to_jiffies(CMD_IN_PRG_INT_MS)); + } + + rc = driver->bus_ops.getscom(driver->bus, OCB_DATA, + (u64 *)resp); + if (rc) + goto err; + + /* retry if we get "command in progress" return status */ + retry = (resp[RESP_RETURN_STATUS] == RESP_RETURN_CMD_IN_PRG) && + (tries++ < CMD_IN_PRG_RETRIES); + } while (retry); + + switch (resp[RESP_RETURN_STATUS]) { + case RESP_RETURN_CMD_IN_PRG: + rc = -EALREADY; + break; + case RESP_RETURN_SUCCESS: + rc = 0; + break; + case RESP_RETURN_CMD_INVAL: + case RESP_RETURN_CMD_LEN: + case RESP_RETURN_DATA_INVAL: + case RESP_RETURN_CHKSUM: + rc = -EINVAL; + break; + case RESP_RETURN_OCC_ERR: + rc = -EREMOTE; + break; + default: + rc = -EFAULT; + } + + return rc; + +err: + dev_err(driver->dev, "scom op failed rc:%d\n", rc); + return rc; +} + +static int occ_get_all(struct occ *driver) +{ + int i = 0, rc; + u8 *occ_data; + u16 num_bytes; + const u8 poll_cmd_data = OCC_POLL_STAT_SENSOR; + struct device *dev = driver->dev; + struct occ_response *resp = &driver->response; + + occ_data = devm_kzalloc(dev, OCC_DATA_MAX, GFP_KERNEL); + if (!occ_data) + return -ENOMEM; + + rc = occ_send_cmd(driver, 0, OCC_POLL, 1, &poll_cmd_data, occ_data); + if (rc) { + dev_err(dev, "OCC poll failed: %d\n", rc); + goto out; + } + + num_bytes = get_unaligned((u16 *)&occ_data[RESP_DATA_LENGTH]); + num_bytes = be16_to_cpu(num_bytes); + dev_dbg(dev, "OCC data length: %d\n", num_bytes); + + if (num_bytes > OCC_DATA_MAX) { + dev_err(dev, "OCC data length must be < 4KB\n"); + rc = -EINVAL; + goto out; + } + + if (num_bytes <= 0) { + dev_err(dev, "OCC data length is zero\n"); + rc = -EINVAL; + goto out; + } + + /* read remaining data */ + for (i = 8; i < num_bytes + 8; i += 8) { + rc = driver->bus_ops.getscom(driver->bus, OCB_DATA, + (u64 *)&occ_data[i]); + if (rc) { + dev_err(dev, "scom op failed rc:%d\n", rc); + goto out; + } + } + + /* don't need more sanity checks; buffer is alloc'd for max response + * size so we just check for valid data in parse_occ_response + */ + rc = parse_occ_response(driver, occ_data, resp); + +out: + devm_kfree(dev, occ_data); + return rc; +} + +int occ_update_device(struct occ *driver) +{ + int rc = 0; + + mutex_lock(&driver->update_lock); + + if (time_after(jiffies, driver->last_updated + driver->update_interval) + || !driver->valid) { + driver->valid = 1; + + rc = occ_get_all(driver); + if (rc) + driver->valid = 0; + + driver->last_updated = jiffies; + } + + mutex_unlock(&driver->update_lock); + + return rc; +} +EXPORT_SYMBOL(occ_update_device); + +void *occ_get_sensor(struct occ *driver, int sensor_type) +{ + int rc; + + /* occ_update_device locks the update lock */ + rc = occ_update_device(driver); + if (rc) { + dev_err(driver->dev, "cannot get occ sensor data: %d\n", + rc); + return NULL; + } + + return occ_get_sensor_by_type(&driver->response, sensor_type); +} +EXPORT_SYMBOL(occ_get_sensor); + +int occ_get_sensor_value(struct occ *occ, int sensor_type, int sensor_num, + u32 hwmon, long *val) +{ + return occ->ops.get_sensor(occ, sensor_type, sensor_num, hwmon, val); +} +EXPORT_SYMBOL(occ_get_sensor_value); + +void occ_get_response_blocks(struct occ *occ, struct occ_blocks **blocks) +{ + *blocks = &occ->response.data; +} +EXPORT_SYMBOL(occ_get_response_blocks); + +void occ_set_update_interval(struct occ *occ, unsigned long interval) +{ + occ->update_interval = msecs_to_jiffies(interval); +} +EXPORT_SYMBOL(occ_set_update_interval); + +int occ_set_user_powercap(struct occ *occ, u16 cap) +{ + u8 resp[8]; + + cap = cpu_to_be16(cap); + + return occ_send_cmd(occ, 0, OCC_SET_USER_POWR_CAP, 2, (const u8 *)&cap, + resp); +} +EXPORT_SYMBOL(occ_set_user_powercap); + +struct occ *occ_start(struct device *dev, void *bus, + struct occ_bus_ops *bus_ops, const struct occ_ops *ops, + const struct occ_config *config) +{ + struct occ *driver = devm_kzalloc(dev, sizeof(struct occ), GFP_KERNEL); + + if (!driver) + return ERR_PTR(-ENOMEM); + + driver->dev = dev; + driver->bus = bus; + driver->bus_ops = *bus_ops; + driver->ops = *ops; + driver->config = *config; + + driver->update_interval = HZ; + mutex_init(&driver->update_lock); + + return driver; +} +EXPORT_SYMBOL(occ_start); + +MODULE_AUTHOR("Eddie James <eajames@xxxxxxxxxx>"); +MODULE_DESCRIPTION("OCC hwmon core driver"); +MODULE_LICENSE("GPL"); diff --git a/drivers/hwmon/occ/occ.h b/drivers/hwmon/occ/occ.h new file mode 100644 index 0000000..c86b06a --- /dev/null +++ b/drivers/hwmon/occ/occ.h @@ -0,0 +1,81 @@ +/* + * occ.h - hwmon OCC driver + * + * This file contains data structures and function prototypes for common access + * between different bus protocols and host systems. + * + * Copyright 2016 IBM Corp. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef __OCC_H__ +#define __OCC_H__ + +#include "scom.h" + +struct device; +struct occ; + +/* sensor_data_block_header + * structure to match the raw occ sensor block header + */ +struct sensor_data_block_header { + u8 sensor_type[4]; + u8 reserved0; + u8 sensor_format; + u8 sensor_length; + u8 sensor_num; +} __attribute__((packed, aligned(4))); + +struct sensor_data_block { + struct sensor_data_block_header header; + void *sensors; +}; + +enum sensor_type { + FREQ = 0, + TEMP, + POWER, + CAPS, + MAX_OCC_SENSOR_TYPE +}; + +struct occ_ops { + void (*parse_sensor)(u8 *data, void *sensor, int sensor_type, int off, + int snum); + void *(*alloc_sensor)(int sensor_type, int num_sensors); + int (*get_sensor)(struct occ *driver, int sensor_type, int sensor_num, + u32 hwmon, long *val); +}; + +struct occ_config { + u32 command_addr; + u32 response_addr; +}; + +struct occ_blocks { + int sensor_block_id[MAX_OCC_SENSOR_TYPE]; + struct sensor_data_block *blocks; +}; + +struct occ *occ_start(struct device *dev, void *bus, + struct occ_bus_ops *bus_ops, const struct occ_ops *ops, + const struct occ_config *config); +void *occ_get_sensor(struct occ *occ, int sensor_type); +int occ_get_sensor_value(struct occ *occ, int sensor_type, int sensor_num, + u32 hwmon, long *val); +void occ_get_response_blocks(struct occ *occ, struct occ_blocks **blocks); +int occ_update_device(struct occ *driver); +void occ_set_update_interval(struct occ *occ, unsigned long interval); +int occ_set_user_powercap(struct occ *occ, u16 cap); + +#endif /* __OCC_H__ */ diff --git a/drivers/hwmon/occ/scom.h b/drivers/hwmon/occ/scom.h new file mode 100644 index 0000000..c1da645 --- /dev/null +++ b/drivers/hwmon/occ/scom.h @@ -0,0 +1,47 @@ +/* + * scom.h - hwmon OCC driver + * + * This file contains data structures for scom operations to the OCC + * + * Copyright 2016 IBM Corp. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef __SCOM_H__ +#define __SCOM_H__ + +/* + * occ_bus_ops - represent the low-level transfer methods to communicate with + * the OCC. + * + * getscom - OCC scom read + * @bus: handle to slave device + * @address: address + * @data: where to store data read from slave; buffer size must be at least + * eight bytes. + * + * Returns 0 on success or a negative errno on error + * + * putscom - OCC scom write + * @bus: handle to slave device + * @address: address + * @data0: first data byte to write + * @data1: second data byte to write + * + * Returns 0 on success or a negative errno on error + */ +struct occ_bus_ops { + int (*getscom)(void *bus, u32 address, u64 *data); + int (*putscom)(void *bus, u32 address, u32 data0, u32 data1); +}; + +#endif /* __SCOM_H__ */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html