[PATCH v4 0/9] hwmon and fsi: Add On-Chip Controller (OCC) driver

[PATCH v4 0/9] hwmon and fsi: Add On-Chip Controller (OCC) driver

[Eddie James]

This series adds a hwmon driver to support the OCC on POWER8 and POWER9
processors. The OCC is an embedded processor that provides realtime power and
thermal monitoring and management.

The series also adds a "bus" driver to handle atomic communication between the
service processor and the OCC on a POWER9 chip. This communication takes place
over FSI bus to the SBE (Self-Boot engine) FIFO, which in turn communicates
with the OCC. The driver for the SBEFIFO is already in linux-next as an FSI
client driver.

For POWER8 OCCs, communication between the service processor and the OCC is
achieved over I2C bus.

Changes since v3:
 * Add the FSI OCC driver.
 * Pull the sysfs attribute code into it's own file for cleanliness.
 * Various fixes for attribute creation and integer overflow.

Changes since v2:
 * Add sysfs_notify for the error and throttling attributes when change is
   detected.
 * Removed occs_present counting of devices bound.
 * Improved remove() of P9 driver to avoid bad behavior with relation to OCC
   driver when unbound.
 * Added default cases (return EINVAL) for all sensor show functions.
 * Added temperature fault sensor.
 * Added back dt binding documentation for P9 to address checkpatch warning.
 * Added occs_present attribute from the poll response.

Changes since v1:
 * Remove wait loop in P9 code, as that is now handled by FSI OCC driver.
 * Removed dt binding documentation for P9, FSI OCC driver will probe OCC hwmon
   driver automatically.
 * Moved OCC response code definitions to the OCC include file.
 * Fixed includes.
 * Changed some structure fields to __beXX as that is what they are.
 * Changed some errnos.
 * Removed some dev_err().
 * Refactored P8 code a bit to use #defined addresses and magic values, and
   changed "goto retry" to a loop.
 * Refactored error handling a bit.

Eddie James (9):
  fsi: Add On-Chip Controller (OCC) driver
  Documentation: hwmon: Add OCC documentation
  dt-bindings: i2c: Add P8 OCC hwmon device documentation
  hwmon: Add On-Chip Controller (OCC) hwmon driver
  hwmon (occ): Add command transport method for P8 and P9
  hwmon (occ): Parse OCC poll response
  hwmon (occ): Add sensor types and versions
  hwmon (occ): Add sensor attributes and register hwmon device
  hwmon (occ): Add sysfs attributes for additional OCC data

 .../devicetree/bindings/i2c/ibm,p8-occ-hwmon.txt   |   25 +
 Documentation/hwmon/occ                            |   73 ++
 drivers/fsi/Kconfig                                |   10 +
 drivers/fsi/Makefile                               |    1 +
 drivers/fsi/fsi-occ.c                              |  609 ++++++++++
 drivers/hwmon/Kconfig                              |    2 +
 drivers/hwmon/Makefile                             |    1 +
 drivers/hwmon/occ/Kconfig                          |   28 +
 drivers/hwmon/occ/Makefile                         |   11 +
 drivers/hwmon/occ/common.c                         | 1250 ++++++++++++++++++++
 drivers/hwmon/occ/common.h                         |  136 +++
 drivers/hwmon/occ/p8_i2c.c                         |  264 +++++
 drivers/hwmon/occ/p9_sbe.c                         |  115 ++
 drivers/hwmon/occ/sysfs.c                          |  188 +++
 include/linux/fsi-occ.h                            |   34 +
 15 files changed, 2747 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/ibm,p8-occ-hwmon.txt
 create mode 100644 Documentation/hwmon/occ
 create mode 100644 drivers/fsi/fsi-occ.c
 create mode 100644 drivers/hwmon/occ/Kconfig
 create mode 100644 drivers/hwmon/occ/Makefile
 create mode 100644 drivers/hwmon/occ/common.c
 create mode 100644 drivers/hwmon/occ/common.h
 create mode 100644 drivers/hwmon/occ/p8_i2c.c
 create mode 100644 drivers/hwmon/occ/p9_sbe.c
 create mode 100644 drivers/hwmon/occ/sysfs.c
 create mode 100644 include/linux/fsi-occ.h

-- 
1.8.3.1

[PATCH v4 1/9] fsi: Add On-Chip Controller (OCC) driver

[Eddie James]

The OCC is a device embedded on a POWER processor that collects and
aggregates sensor data from the processor and system. The OCC can
provide the raw sensor data as well as perform thermal and power
management on the system.

This driver provides an atomic communications channel between a service
processor (e.g. a BMC) and the OCC. The driver is dependent on the FSI
SBEFIFO driver to get hardware access through the SBE to the OCC SRAM.
Commands are issued to the SBE to send or fetch data to the SRAM.

Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 drivers/fsi/Kconfig     |  10 +
 drivers/fsi/Makefile    |   1 +
 drivers/fsi/fsi-occ.c   | 609 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/fsi-occ.h |  34 +++
 4 files changed, 654 insertions(+)
 create mode 100644 drivers/fsi/fsi-occ.c
 create mode 100644 include/linux/fsi-occ.h

diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig
index 24f84a9..322cec3 100644
--- a/drivers/fsi/Kconfig
+++ b/drivers/fsi/Kconfig
@@ -39,4 +39,14 @@ config FSI_SBEFIFO
 	a pipe-like FSI device for communicating with the self boot engine
 	(SBE) on POWER processors.
 
+config FSI_OCC
+	tristate "OCC SBEFIFO client device driver"
+	depends on FSI_SBEFIFO
+	---help---
+	This option enables an SBEFIFO based On-Chip Controller (OCC) device
+	driver. The OCC is a device embedded on a POWER processor that collects
+	and aggregates sensor data from the processor and system. The OCC can
+	provide the raw sensor data as well as perform thermal and power
+	management on the system.
+
 endif
diff --git a/drivers/fsi/Makefile b/drivers/fsi/Makefile
index 851182e..75fdc6d 100644
--- a/drivers/fsi/Makefile
+++ b/drivers/fsi/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_FSI_MASTER_HUB) += fsi-master-hub.o
 obj-$(CONFIG_FSI_MASTER_GPIO) += fsi-master-gpio.o
 obj-$(CONFIG_FSI_SCOM) += fsi-scom.o
 obj-$(CONFIG_FSI_SBEFIFO) += fsi-sbefifo.o
+obj-$(CONFIG_FSI_OCC) += fsi-occ.o
diff --git a/drivers/fsi/fsi-occ.c b/drivers/fsi/fsi-occ.c
new file mode 100644
index 0000000..bba67a6
--- /dev/null
+++ b/drivers/fsi/fsi-occ.c
@@ -0,0 +1,609 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * On-Chip Controller Driver
+ *
+ * Copyright (C) IBM Corporation 2018
+ *
+ * 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.
+ */
+
+#include <asm/unaligned.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/fsi-sbefifo.h>
+#include <linux/gfp.h>
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/fsi-occ.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#define OCC_SRAM_BYTES		4096
+#define OCC_CMD_DATA_BYTES	4090
+#define OCC_RESP_DATA_BYTES	4089
+
+#define OCC_SRAM_CMD_ADDR	0xFFFBE000
+#define OCC_SRAM_RSP_ADDR	0xFFFBF000
+
+/*
+ * Assume we don't have much FFDC, if we do we'll overflow and
+ * fail the command. This needs to be big enough for simple
+ * commands as well.
+ */
+#define OCC_SBE_STATUS_WORDS	32
+
+#define OCC_TIMEOUT_MS		1000
+#define OCC_CMD_IN_PRG_WAIT_MS	50
+
+struct occ {
+	struct device *dev;
+	struct device *sbefifo;
+	char name[32];
+	int idx;
+	struct miscdevice mdev;
+	struct mutex occ_lock;
+};
+
+#define to_occ(x)	container_of((x), struct occ, mdev)
+
+struct occ_response {
+	u8 seq_no;
+	u8 cmd_type;
+	u8 return_status;
+	__be16 data_length;
+	u8 data[OCC_RESP_DATA_BYTES + 2];	/* two bytes checksum */
+} __packed;
+
+struct occ_client {
+	struct occ *occ;
+	struct mutex lock;
+	size_t data_size;
+	size_t read_offset;
+	u8 *buffer;
+};
+
+#define to_client(x)	container_of((x), struct occ_client, xfr)
+
+static DEFINE_IDA(occ_ida);
+
+static int occ_open(struct inode *inode, struct file *file)
+{
+	struct occ_client *client = kzalloc(sizeof(*client), GFP_KERNEL);
+	struct miscdevice *mdev = file->private_data;
+	struct occ *occ = to_occ(mdev);
+
+	if (!client)
+		return -ENOMEM;
+
+	client->buffer = (u8 *)__get_free_page(GFP_KERNEL);
+	if (!client->buffer) {
+		kfree(client);
+		return -ENOMEM;
+	}
+
+	client->occ = occ;
+	mutex_init(&client->lock);
+	file->private_data = client;
+
+	/* We allocate a 1-page buffer, make sure it all fits */
+	BUILD_BUG_ON((OCC_CMD_DATA_BYTES + 3) > PAGE_SIZE);
+	BUILD_BUG_ON((OCC_RESP_DATA_BYTES + 7) > PAGE_SIZE);
+
+	return 0;
+}
+
+static ssize_t occ_read(struct file *file, char __user *buf, size_t len,
+			loff_t *offset)
+{
+	struct occ_client *client = file->private_data;
+	ssize_t rc = 0;
+
+	if (!client)
+		return -ENODEV;
+
+	if (len > OCC_SRAM_BYTES)
+		return -EINVAL;
+
+	mutex_lock(&client->lock);
+
+	/* This should not be possible ... */
+	if (WARN_ON_ONCE(client->read_offset > client->data_size)) {
+		rc = -EIO;
+		goto done;
+	}
+
+	/* Grab how much data we have to read */
+	rc = min(len, client->data_size - client->read_offset);
+	if (copy_to_user(buf, client->buffer + client->read_offset, rc))
+		rc = -EFAULT;
+	else
+		client->read_offset += rc;
+
+ done:
+	mutex_unlock(&client->lock);
+
+	return rc;
+}
+
+static ssize_t occ_write(struct file *file, const char __user *buf,
+			 size_t len, loff_t *offset)
+{
+	struct occ_client *client = file->private_data;
+	size_t rlen, data_length;
+	u16 checksum = 0;
+	ssize_t rc, i;
+	u8 *cmd;
+
+	if (!client)
+		return -ENODEV;
+
+	if (len > (OCC_CMD_DATA_BYTES + 3) || len < 3)
+		return -EINVAL;
+
+	mutex_lock(&client->lock);
+
+	/* Construct the command */
+	cmd = client->buffer;
+
+	/* Sequence number (we could increment and compare with response) */
+	cmd[0] = 1;
+
+	/*
+	 * Copy the user command (assume user data follows the occ command
+	 * format)
+	 * byte 0: command type
+	 * bytes 1-2: data length (msb first)
+	 * bytes 3-n: data
+	 */
+	if (copy_from_user(&cmd[1], buf, len)) {
+		rc = -EFAULT;
+		goto done;
+	}
+
+	/* Extract data length */
+	data_length = (cmd[2] << 8) + cmd[3];
+	if (data_length > OCC_CMD_DATA_BYTES) {
+		rc = -EINVAL;
+		goto done;
+	}
+
+	/* Calculate checksum */
+	for (i = 0; i < data_length + 4; ++i)
+		checksum += cmd[i];
+
+	cmd[data_length + 4] = checksum >> 8;
+	cmd[data_length + 5] = checksum & 0xFF;
+
+	/* Submit command */
+	rlen = PAGE_SIZE;
+	rc = fsi_occ_submit(client->occ->dev, cmd, data_length + 6, cmd,
+			    &rlen);
+	if (rc)
+		goto done;
+
+	/* Set read tracking data */
+	client->data_size = rlen;
+	client->read_offset = 0;
+
+	/* Done */
+	rc = len;
+
+ done:
+	mutex_unlock(&client->lock);
+
+	return rc;
+}
+
+static int occ_release(struct inode *inode, struct file *file)
+{
+	struct occ_client *client = file->private_data;
+
+	free_page((unsigned long)client->buffer);
+	kfree(client);
+
+	return 0;
+}
+
+static const struct file_operations occ_fops = {
+	.owner = THIS_MODULE,
+	.open = occ_open,
+	.read = occ_read,
+	.write = occ_write,
+	.release = occ_release,
+};
+
+static int occ_verify_checksum(struct occ_response *resp, u16 data_length)
+{
+	/* Fetch the two bytes after the data for the checksum. */
+	u16 checksum_resp = get_unaligned_be16(&resp->data[data_length]);
+	u16 checksum;
+	u16 i;
+
+	checksum = resp->seq_no;
+	checksum += resp->cmd_type;
+	checksum += resp->return_status;
+	checksum += (data_length >> 8) + (data_length & 0xFF);
+
+	for (i = 0; i < data_length; ++i)
+		checksum += resp->data[i];
+
+	if (checksum != checksum_resp)
+		return -EBADMSG;
+
+	return 0;
+}
+
+static int occ_getsram(struct occ *occ, u32 address, void *data, ssize_t len)
+{
+	u32 data_len = ((len + 7) / 8) * 8;	/* must be multiples of 8 B */
+	size_t resp_len, resp_data_len;
+	__be32 *resp, cmd[5];
+	int rc;
+
+	/*
+	 * Magic sequence to do SBE getsram command. SBE will fetch data from
+	 * specified SRAM address.
+	 */
+	cmd[0] = cpu_to_be32(0x5);
+	cmd[1] = cpu_to_be32(SBEFIFO_CMD_GET_OCC_SRAM);
+	cmd[2] = cpu_to_be32(1);
+	cmd[3] = cpu_to_be32(address);
+	cmd[4] = cpu_to_be32(data_len);
+
+	resp_len = (data_len >> 2) + OCC_SBE_STATUS_WORDS;
+	resp = kzalloc(resp_len << 2, GFP_KERNEL);
+	if (!resp)
+		return -ENOMEM;
+
+	rc = sbefifo_submit(occ->sbefifo, cmd, 5, resp, &resp_len);
+	if (rc)
+		goto free;
+
+	rc = sbefifo_parse_status(occ->sbefifo, SBEFIFO_CMD_GET_OCC_SRAM,
+				  resp, resp_len, &resp_len);
+	if (rc)
+		goto free;
+
+	resp_data_len = be32_to_cpu(resp[resp_len - 1]);
+	if (resp_data_len != data_len) {
+		dev_err(occ->dev, "SRAM read expected %d bytes got %zd\n",
+			data_len, resp_data_len);
+		rc = -EBADMSG;
+	} else {
+		memcpy(data, resp, len);
+	}
+
+free:
+	/* Convert positive SBEI status */
+	if (rc > 0) {
+		dev_err(occ->dev, "SRAM read returned failure status: %08x\n",
+			rc);
+		rc = -EBADMSG;
+	}
+
+	kfree(resp);
+	return rc;
+}
+
+static int occ_putsram(struct occ *occ, u32 address, const void *data,
+		       ssize_t len)
+{
+	size_t cmd_len, buf_len, resp_len, resp_data_len;
+	u32 data_len = ((len + 7) / 8) * 8;	/* must be multiples of 8 B */
+	__be32 *buf;
+	int rc;
+
+	/*
+	 * We use the same buffer for command and response, make
+	 * sure it's big enough
+	 */
+	resp_len = OCC_SBE_STATUS_WORDS;
+	cmd_len = (data_len >> 2) + 5;
+	buf_len = max(cmd_len, resp_len);
+	buf = kzalloc(buf_len << 2, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/*
+	 * Magic sequence to do SBE putsram command. SBE will transfer
+	 * data to specified SRAM address.
+	 */
+	buf[0] = cpu_to_be32(cmd_len);
+	buf[1] = cpu_to_be32(SBEFIFO_CMD_PUT_OCC_SRAM);
+	buf[2] = cpu_to_be32(1);
+	buf[3] = cpu_to_be32(address);
+	buf[4] = cpu_to_be32(data_len);
+
+	memcpy(&buf[5], data, len);
+
+	rc = sbefifo_submit(occ->sbefifo, buf, cmd_len, buf, &resp_len);
+	if (rc)
+		goto free;
+
+	rc = sbefifo_parse_status(occ->sbefifo, SBEFIFO_CMD_PUT_OCC_SRAM,
+				  buf, resp_len, &resp_len);
+	if (rc)
+		goto free;
+
+	if (resp_len != 1) {
+		dev_err(occ->dev, "SRAM write response length invalid: %zd\n",
+			resp_len);
+		rc = -EBADMSG;
+	} else {
+		resp_data_len = be32_to_cpu(buf[0]);
+		if (resp_data_len != data_len) {
+			dev_err(occ->dev,
+				"SRAM write expected %d bytes got %zd\n",
+				data_len, resp_data_len);
+			rc = -EBADMSG;
+		}
+	}
+
+free:
+	/* Convert positive SBEI status */
+	if (rc > 0) {
+		dev_err(occ->dev, "SRAM write returned failure status: %08x\n",
+			rc);
+		rc = -EBADMSG;
+	}
+
+	kfree(buf);
+	return rc;
+}
+
+static int occ_trigger_attn(struct occ *occ)
+{
+	__be32 buf[OCC_SBE_STATUS_WORDS];
+	size_t resp_len, resp_data_len;
+	int rc;
+
+	BUILD_BUG_ON(OCC_SBE_STATUS_WORDS < 7);
+	resp_len = OCC_SBE_STATUS_WORDS;
+
+	buf[0] = cpu_to_be32(0x5 + 0x2);        /* Chip-op length in words */
+	buf[1] = cpu_to_be32(SBEFIFO_CMD_PUT_OCC_SRAM);
+	buf[2] = cpu_to_be32(0x3);              /* Mode: Circular */
+	buf[3] = cpu_to_be32(0x0);              /* Address: ignore in mode 3 */
+	buf[4] = cpu_to_be32(0x8);              /* Data length in bytes */
+	buf[5] = cpu_to_be32(0x20010000);       /* Trigger OCC attention */
+	buf[6] = 0;
+
+	rc = sbefifo_submit(occ->sbefifo, buf, 7, buf, &resp_len);
+	if (rc)
+		goto error;
+
+	rc = sbefifo_parse_status(occ->sbefifo, SBEFIFO_CMD_PUT_OCC_SRAM,
+				  buf, resp_len, &resp_len);
+	if (rc)
+		goto error;
+
+	if (resp_len != 1) {
+		dev_err(occ->dev, "SRAM attn response length invalid: %zd\n",
+			resp_len);
+		rc = -EBADMSG;
+	} else {
+		resp_data_len = be32_to_cpu(buf[0]);
+		if (resp_data_len != 8) {
+			dev_err(occ->dev,
+				"SRAM attn expected 8 bytes got %zd\n",
+				resp_data_len);
+			rc = -EBADMSG;
+		}
+	}
+
+ error:
+	/* Convert positive SBEI status */
+	if (rc > 0) {
+		dev_err(occ->dev, "SRAM attn returned failure status: %08x\n",
+			rc);
+		rc = -EBADMSG;
+	}
+
+	return rc;
+}
+
+int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
+		   void *response, size_t *resp_len)
+{
+	const unsigned long timeout = msecs_to_jiffies(OCC_TIMEOUT_MS);
+	const unsigned long wait_time =
+		msecs_to_jiffies(OCC_CMD_IN_PRG_WAIT_MS);
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_response *resp = response;
+	u16 resp_data_length;
+	unsigned long start;
+	int rc;
+
+	if (!occ)
+		return -ENODEV;
+
+	if (*resp_len < 7) {
+		dev_dbg(dev, "Bad resplen %zd\n", *resp_len);
+		return -EINVAL;
+	}
+
+	mutex_lock(&occ->occ_lock);
+
+	rc = occ_putsram(occ, OCC_SRAM_CMD_ADDR, request, req_len);
+	if (rc)
+		goto done;
+
+	rc = occ_trigger_attn(occ);
+	if (rc)
+		goto done;
+
+	/* Read occ response header */
+	start = jiffies;
+	do {
+		rc = occ_getsram(occ, OCC_SRAM_RSP_ADDR, resp, 8);
+		if (rc)
+			goto done;
+
+		if (resp->return_status == OCC_RESP_CMD_IN_PRG) {
+			rc = -ETIMEDOUT;
+
+			if (time_after(jiffies, start + timeout))
+				break;
+
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			schedule_timeout(wait_time);
+		}
+	} while (rc);
+
+	/* Extract size of response data */
+	resp_data_length = get_unaligned_be16(&resp->data_length);
+
+	/* Message size is data length + 5 bytes header + 2 bytes checksum */
+	if ((resp_data_length + 7) > *resp_len) {
+		rc = -EMSGSIZE;
+		goto done;
+	}
+
+	dev_dbg(dev, "resp_status=%02x resp_data_len=%d\n",
+		resp->return_status, resp_data_length);
+
+	/* Grab the rest */
+	if (resp_data_length > 1) {
+		/* already got 3 bytes resp, also need 2 bytes checksum */
+		rc = occ_getsram(occ, OCC_SRAM_RSP_ADDR + 8,
+				 &resp->data[3], resp_data_length - 1);
+		if (rc)
+			goto done;
+	}
+
+	*resp_len = resp_data_length + 7;
+	rc = occ_verify_checksum(resp, resp_data_length);
+
+ done:
+	mutex_unlock(&occ->occ_lock);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(fsi_occ_submit);
+
+static int occ_unregister_child(struct device *dev, void *data)
+{
+	struct platform_device *hwmon_dev = to_platform_device(dev);
+
+	platform_device_unregister(hwmon_dev);
+
+	return 0;
+}
+
+static int occ_probe(struct platform_device *pdev)
+{
+	int rc;
+	u32 reg;
+	struct occ *occ;
+	struct platform_device *hwmon_dev;
+	struct device *dev = &pdev->dev;
+	struct platform_device_info hwmon_dev_info = {
+		.parent = dev,
+		.name = "occ-hwmon",
+	};
+
+	occ = devm_kzalloc(dev, sizeof(*occ), GFP_KERNEL);
+	if (!occ)
+		return -ENOMEM;
+
+	occ->dev = dev;
+	occ->sbefifo = dev->parent;
+	mutex_init(&occ->occ_lock);
+
+	if (dev->of_node) {
+		rc = of_property_read_u32(dev->of_node, "reg", &reg);
+		if (!rc) {
+			/* make sure we don't have a duplicate from dts */
+			occ->idx = ida_simple_get(&occ_ida, reg, reg + 1,
+						  GFP_KERNEL);
+			if (occ->idx < 0)
+				occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX,
+							  GFP_KERNEL);
+		} else {
+			occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX,
+						  GFP_KERNEL);
+		}
+	} else {
+		occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX, GFP_KERNEL);
+	}
+
+	platform_set_drvdata(pdev, occ);
+
+	snprintf(occ->name, sizeof(occ->name), "occ%d", occ->idx);
+	occ->mdev.fops = &occ_fops;
+	occ->mdev.minor = MISC_DYNAMIC_MINOR;
+	occ->mdev.name = occ->name;
+	occ->mdev.parent = dev;
+
+	rc = misc_register(&occ->mdev);
+	if (rc) {
+		dev_err(dev, "failed to register miscdevice: %d\n", rc);
+		ida_simple_remove(&occ_ida, occ->idx);
+		return rc;
+	}
+
+	hwmon_dev_info.id = occ->idx;
+	hwmon_dev = platform_device_register_full(&hwmon_dev_info);
+	if (!hwmon_dev)
+		dev_warn(dev, "failed to create hwmon device\n");
+
+	return 0;
+}
+
+static int occ_remove(struct platform_device *pdev)
+{
+	struct occ *occ = platform_get_drvdata(pdev);
+
+	misc_deregister(&occ->mdev);
+
+	device_for_each_child(&pdev->dev, NULL, occ_unregister_child);
+
+	ida_simple_remove(&occ_ida, occ->idx);
+
+	return 0;
+}
+
+static const struct of_device_id occ_match[] = {
+	{ .compatible = "ibm,p9-occ" },
+	{ },
+};
+
+static struct platform_driver occ_driver = {
+	.driver = {
+		.name = "occ",
+		.of_match_table	= occ_match,
+	},
+	.probe	= occ_probe,
+	.remove = occ_remove,
+};
+
+static int occ_init(void)
+{
+	return platform_driver_register(&occ_driver);
+}
+
+static void occ_exit(void)
+{
+	platform_driver_unregister(&occ_driver);
+
+	ida_destroy(&occ_ida);
+}
+
+module_init(occ_init);
+module_exit(occ_exit);
+
+MODULE_AUTHOR("Eddie James <eajames@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("BMC P9 OCC driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/fsi-occ.h b/include/linux/fsi-occ.h
new file mode 100644
index 0000000..e28cf9a
--- /dev/null
+++ b/include/linux/fsi-occ.h
@@ -0,0 +1,34 @@
+/*
+ * On-Chip Controller Driver definitions and prototypes
+ *
+ * Copyright (C) IBM Corporation 2018
+ *
+ * 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.
+ */
+
+#ifndef LINUX_FSI_OCC_H
+#define LINUX_FSI_OCC_H
+
+struct device;
+
+#define OCC_RESP_CMD_IN_PRG		0xFF
+#define OCC_RESP_SUCCESS		0
+#define OCC_RESP_CMD_INVAL		0x11
+#define OCC_RESP_CMD_LEN_INVAL		0x12
+#define OCC_RESP_DATA_INVAL		0x13
+#define OCC_RESP_CHKSUM_ERR		0x14
+#define OCC_RESP_INT_ERR		0x15
+#define OCC_RESP_BAD_STATE		0x16
+#define OCC_RESP_CRIT_EXCEPT		0xE0
+#define OCC_RESP_CRIT_INIT		0xE1
+#define OCC_RESP_CRIT_WATCHDOG		0xE2
+#define OCC_RESP_CRIT_OCB		0xE3
+#define OCC_RESP_CRIT_HW		0xE4
+
+int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
+		   void *response, size_t *resp_len);
+
+#endif /* LINUX_FSI_OCC_H */
-- 
1.8.3.1

[PATCH v4 2/9] Documentation: hwmon: Add OCC documentation

[Eddie James]

Document the hwmon interface for the OCC.

Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
---
 Documentation/hwmon/occ | 73 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 Documentation/hwmon/occ

diff --git a/Documentation/hwmon/occ b/Documentation/hwmon/occ
new file mode 100644
index 0000000..465fa1a
--- /dev/null
+++ b/Documentation/hwmon/occ
@@ -0,0 +1,73 @@
+Kernel driver occ-hwmon
+=======================
+
+Supported chips:
+  * POWER8
+  * POWER9
+
+Author: Eddie James <eajames@linux.vnet.ibm.com>
+
+Description
+-----------
+
+This driver supports hardware monitoring for the On-Chip Controller (OCC)
+embedded on POWER processors. The OCC is a device that collects and aggregates
+sensor data from the processor and the system. The OCC can provide the raw
+sensor data as well as perform thermal and power management on the system.
+
+The P8 version of this driver is a client driver of I2C. It may be probed
+manually if an "ibm,p8-occ-hwmon" compatible device is found under the
+appropriate I2C bus node in the device-tree.
+
+The P9 version of this driver is a client driver of the FSI-based OCC driver.
+It will be probed automatically by the FSI-based OCC driver.
+
+Sysfs entries
+-------------
+
+The following attributes are supported. All attributes are read-only unless
+specified.
+
+temp[1-n]_label		OCC sensor id.
+temp[1-n]_input		Measured temperature in millidegrees C.
+[with temperature sensor version 2+]
+    temp[1-n]_fru_type		Given FRU (Field Replaceable Unit) type.
+    temp[1-n]_fault		Temperature sensor fault.
+
+freq[1-n]_label		OCC sensor id.
+freq[1-n]_input		Measured frequency.
+
+power[1-n]_label	OCC sensor id.
+power[1-n]_input	Measured power in microwatts.
+power[1-n]_update_tag	Number of 250us samples represented in accumulator.
+power[1-n]_accumulator	Accumulation of 250us power readings.
+[with power sensor version 2+]
+    power[1-n]_function_id	Identifies what the power reading is for.
+    power[1-n]_apss_channel	Indicates APSS channel.
+
+[power version 0xa0 only]
+power1_id			OCC sensor id.
+power[1-n]_label		Sensor type, "system", "proc", "vdd", or "vdn".
+power[1-n]_input		Most recent power reading in microwatts.
+power[1-n]_update_tag		Number of samples in the accumulator.
+power[1-n]_accumulator		Accumulation of power readings.
+[with sensor type "system" and "proc" only]
+    power[1-n]_update_time	Time in us that the power value is read.
+
+caps1_current		Current OCC power cap in watts.
+caps1_reading		Current system output power in watts.
+caps1_norm		Power cap without redundant power.
+caps1_max		Maximum power cap.
+[caps version 1 and 2 only]
+    caps1_min		Minimum power cap.
+[caps version 3+]
+    caps1_min_hard		Hard minimum cap that can be set and held.
+    caps1_min_soft		Soft minimum cap below hard, not guaranteed.
+caps1_user		The powercap specified by the user. Will be 0 if no
+			user powercap exists. This attribute is read-write.
+[caps version 1+]
+    caps1_user_source	Indicates how the user power limit was set.
+
+extn[1-n]_label		ASCII id or sensor id.
+extn[1-n]_flags		Indicates type of label attribute.
+extn[1-n]_input		Data.
-- 
1.8.3.1

[PATCH v4 3/9] dt-bindings: i2c: Add P8 OCC hwmon device documentation

[Eddie James]

Document the bindings for I2C-based OCC hwmon device.

Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../devicetree/bindings/i2c/ibm,p8-occ-hwmon.txt   | 25 ++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/ibm,p8-occ-hwmon.txt

diff --git a/Documentation/devicetree/bindings/i2c/ibm,p8-occ-hwmon.txt b/Documentation/devicetree/bindings/i2c/ibm,p8-occ-hwmon.txt
new file mode 100644
index 0000000..5dc5d2e
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/ibm,p8-occ-hwmon.txt
@@ -0,0 +1,25 @@
+Device-tree bindings for I2C-based On-Chip Controller hwmon device
+------------------------------------------------------------------
+
+Required properties:
+ - compatible = "ibm,p8-occ-hwmon";
+ - reg = <I2C address>;			: I2C bus address
+
+Examples:
+
+    i2c-bus@100 {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        clock-frequency = <100000>;
+        < more properties >
+
+        occ-hwmon@1 {
+            compatible = "ibm,p8-occ-hwmon";
+            reg = <0x50>;
+        };
+
+        occ-hwmon@2 {
+            compatible = "ibm,p8-occ-hwmon";
+            reg = <0x51>;
+        };
+    };
-- 
1.8.3.1

[PATCH v4 4/9] hwmon: Add On-Chip Controller (OCC) hwmon driver

[Eddie James]

The OCC is a device embedded on a POWER processor that collects and
aggregates sensor data from the processor and system. The OCC can
provide the raw sensor data as well as perform thermal and power
management on the system.

This driver provides a hwmon interface to the OCC from a service
processor (e.g. a BMC). The driver supports both POWER8 and POWER9 OCCs.
Communications with the POWER8 OCC are established over standard I2C
bus. The driver communicates with the POWER9 OCC through the FSI-based
OCC driver, which handles the lower-level communication details.

This patch lays out the structure of the OCC hwmon driver. There are two
platform drivers, one each for P8 and P9 OCCs. These are probed through
the I2C tree and the FSI-based OCC driver, respectively. The patch also
defines the first common structures and methods between the two OCC
versions.

Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
---
 drivers/hwmon/Kconfig      |  2 ++
 drivers/hwmon/Makefile     |  1 +
 drivers/hwmon/occ/Kconfig  | 28 +++++++++++++++++
 drivers/hwmon/occ/Makefile | 11 +++++++
 drivers/hwmon/occ/common.c | 50 +++++++++++++++++++++++++++++
 drivers/hwmon/occ/common.h | 43 +++++++++++++++++++++++++
 drivers/hwmon/occ/p8_i2c.c | 71 +++++++++++++++++++++++++++++++++++++++++
 drivers/hwmon/occ/p9_sbe.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++
 8 files changed, 284 insertions(+)
 create mode 100644 drivers/hwmon/occ/Kconfig
 create mode 100644 drivers/hwmon/occ/Makefile
 create mode 100644 drivers/hwmon/occ/common.c
 create mode 100644 drivers/hwmon/occ/common.h
 create mode 100644 drivers/hwmon/occ/p8_i2c.c
 create mode 100644 drivers/hwmon/occ/p9_sbe.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index a4e5d3c..9b3871e 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1293,6 +1293,8 @@ 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 93f7f41..f5c7b44 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -178,6 +178,7 @@ obj-$(CONFIG_SENSORS_WM831X)	+= wm831x-hwmon.o
 obj-$(CONFIG_SENSORS_WM8350)	+= wm8350-hwmon.o
 obj-$(CONFIG_SENSORS_XGENE)	+= xgene-hwmon.o
 
+obj-$(CONFIG_SENSORS_OCC)	+= occ/
 obj-$(CONFIG_PMBUS)		+= pmbus/
 
 ccflags-$(CONFIG_HWMON_DEBUG_CHIP) := -DDEBUG
diff --git a/drivers/hwmon/occ/Kconfig b/drivers/hwmon/occ/Kconfig
new file mode 100644
index 0000000..9579b63
--- /dev/null
+++ b/drivers/hwmon/occ/Kconfig
@@ -0,0 +1,28 @@
+#
+# On-Chip Controller configuration
+#
+
+config SENSORS_OCC
+	tristate "POWER On-Chip Controller"
+	help
+	 This option enables support for monitoring a variety of system sensors
+	 provided by the On-Chip Controller (OCC) on a POWER processor.
+
+	 This driver can also be built as a module. If so, the module will be
+	 called occ-hwmon.
+
+config SENSORS_OCC_P8_I2C
+	bool "POWER8 OCC through I2C"
+	depends on I2C && SENSORS_OCC
+	help
+	 This option enables support for monitoring sensors provided by the OCC
+	 on a POWER8 processor. Communications with the OCC are established
+	 through I2C bus.
+
+config SENSORS_OCC_P9_SBE
+	bool "POWER9 OCC through SBE"
+	depends on FSI_OCC && SENSORS_OCC
+	help
+	 This option enables support for monitoring sensors provided by the OCC
+	 on a POWER9 processor. Communications with the OCC are established
+	 through SBEFIFO on an FSI bus.
diff --git a/drivers/hwmon/occ/Makefile b/drivers/hwmon/occ/Makefile
new file mode 100644
index 0000000..ab5c3e9
--- /dev/null
+++ b/drivers/hwmon/occ/Makefile
@@ -0,0 +1,11 @@
+occ-hwmon-objs := common.o
+
+ifeq ($(CONFIG_SENSORS_OCC_P9_SBE), y)
+occ-hwmon-objs += p9_sbe.o
+endif
+
+ifeq ($(CONFIG_SENSORS_OCC_P8_I2C), y)
+occ-hwmon-objs += p8_i2c.o
+endif
+
+obj-$(CONFIG_SENSORS_OCC) += occ-hwmon.o
diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
new file mode 100644
index 0000000..1fd3453
--- /dev/null
+++ b/drivers/hwmon/occ/common.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * OCC hwmon driver common functionality
+ *
+ * Copyright (C) IBM Corporation 2018
+ *
+ * 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.
+ */
+
+#include <linux/device.h>
+
+#include "common.h"
+
+static int occ_poll(struct occ *occ)
+{
+	u16 checksum = occ->poll_cmd_data + 1;
+	u8 cmd[8];
+
+	/* big endian */
+	cmd[0] = 0;			/* sequence number */
+	cmd[1] = 0;			/* cmd type */
+	cmd[2] = 0;			/* data length msb */
+	cmd[3] = 1;			/* data length lsb */
+	cmd[4] = occ->poll_cmd_data;	/* data */
+	cmd[5] = checksum >> 8;		/* checksum msb */
+	cmd[6] = checksum & 0xFF;	/* checksum lsb */
+	cmd[7] = 0;
+
+	return occ->send_cmd(occ, cmd);
+}
+
+int occ_setup(struct occ *occ, const char *name)
+{
+	int rc;
+
+	rc = occ_poll(occ);
+	if (rc == -ESHUTDOWN) {
+		dev_info(occ->bus_dev, "host is not ready\n");
+		return rc;
+	} else if (rc < 0) {
+		dev_err(occ->bus_dev, "failed to get OCC poll response: %d\n",
+			rc);
+		return rc;
+	}
+
+	return 0;
+}
diff --git a/drivers/hwmon/occ/common.h b/drivers/hwmon/occ/common.h
new file mode 100644
index 0000000..775b421
--- /dev/null
+++ b/drivers/hwmon/occ/common.h
@@ -0,0 +1,43 @@
+/*
+ * OCC hwmon driver common definitions, structures, and prototypes
+ *
+ * Copyright (C) IBM Corporation 2018
+ *
+ * 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.
+ */
+
+#ifndef OCC_COMMON_H
+#define OCC_COMMON_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 {
+	struct device *bus_dev;
+
+	struct occ_response resp;
+
+	u8 poll_cmd_data;		/* to perform OCC poll command */
+	int (*send_cmd)(struct occ *occ, u8 *cmd);
+};
+
+int occ_setup(struct occ *occ, const char *name);
+
+#endif /* OCC_COMMON_H */
diff --git a/drivers/hwmon/occ/p8_i2c.c b/drivers/hwmon/occ/p8_i2c.c
new file mode 100644
index 0000000..899294b
--- /dev/null
+++ b/drivers/hwmon/occ/p8_i2c.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * OCC hwmon P8 driver
+ *
+ * Copyright (C) IBM Corporation 2018
+ *
+ * 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.
+ */
+
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+
+#include "common.h"
+
+struct p8_i2c_occ {
+	struct occ occ;
+	struct i2c_client *client;
+};
+
+#define to_p8_i2c_occ(x)	container_of((x), struct p8_i2c_occ, occ)
+
+static int p8_i2c_occ_send_cmd(struct occ *occ, u8 *cmd)
+{
+	return -EOPNOTSUPP;
+}
+
+static int p8_i2c_occ_probe(struct i2c_client *client,
+			    const struct i2c_device_id *id)
+{
+	struct occ *occ;
+	struct p8_i2c_occ *ctx = devm_kzalloc(&client->dev, sizeof(*ctx),
+					      GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->client = client;
+	occ = &ctx->occ;
+	occ->bus_dev = &client->dev;
+	dev_set_drvdata(&client->dev, occ);
+
+	occ->poll_cmd_data = 0x10;		/* P8 OCC poll data */
+	occ->send_cmd = p8_i2c_occ_send_cmd;
+
+	return occ_setup(occ, "p8_occ");
+}
+
+static const struct of_device_id p8_i2c_occ_of_match[] = {
+	{ .compatible = "ibm,p8-occ-hwmon" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, p8_i2c_occ_of_match);
+
+static struct i2c_driver p8_i2c_occ_driver = {
+	.class = I2C_CLASS_HWMON,
+	.driver = {
+		.name = "occ-hwmon",
+		.of_match_table = p8_i2c_occ_of_match,
+	},
+	.probe = p8_i2c_occ_probe,
+};
+
+module_i2c_driver(p8_i2c_occ_driver);
+
+MODULE_AUTHOR("Eddie James <eajames@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("BMC P8 OCC hwmon driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hwmon/occ/p9_sbe.c b/drivers/hwmon/occ/p9_sbe.c
new file mode 100644
index 0000000..7c026a5
--- /dev/null
+++ b/drivers/hwmon/occ/p9_sbe.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * OCC hwmon P9 driver
+ *
+ * Copyright (C) IBM Corporation 2018
+ *
+ * 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.
+ */
+
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "common.h"
+
+struct p9_sbe_occ {
+	struct occ occ;
+	struct device *sbe;
+};
+
+#define to_p9_sbe_occ(x)	container_of((x), struct p9_sbe_occ, occ)
+
+static int p9_sbe_occ_send_cmd(struct occ *occ, u8 *cmd)
+{
+	return -EOPNOTSUPP;
+}
+
+static int p9_sbe_occ_probe(struct platform_device *pdev)
+{
+	int rc;
+	struct occ *occ;
+	struct p9_sbe_occ *ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx),
+					      GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->sbe = pdev->dev.parent;
+	occ = &ctx->occ;
+	occ->bus_dev = &pdev->dev;
+	platform_set_drvdata(pdev, occ);
+
+	occ->poll_cmd_data = 0x20;		/* P9 OCC poll data */
+	occ->send_cmd = p9_sbe_occ_send_cmd;
+
+	rc = occ_setup(occ, "p9_occ");
+	if (rc == -ESHUTDOWN)
+		rc = -ENODEV;	/* Host is shutdown, don't spew errors */
+
+	return rc;
+}
+
+static int p9_sbe_occ_remove(struct platform_device *pdev)
+{
+	struct occ *occ = platform_get_drvdata(pdev);
+	struct p9_sbe_occ *ctx = to_p9_sbe_occ(occ);
+
+	ctx->sbe = NULL;
+
+	return 0;
+}
+
+static struct platform_driver p9_sbe_occ_driver = {
+	.driver = {
+		.name = "occ-hwmon",
+	},
+	.probe	= p9_sbe_occ_probe,
+	.remove = p9_sbe_occ_remove,
+};
+
+module_platform_driver(p9_sbe_occ_driver);
+
+MODULE_AUTHOR("Eddie James <eajames@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("BMC P9 OCC hwmon driver");
+MODULE_LICENSE("GPL");
-- 
1.8.3.1

[PATCH v4 5/9] hwmon (occ): Add command transport method for P8 and P9

[Eddie James]

For the P8 OCC, add the procedure to send a command to the OCC over I2C
bus. This involves writing the OCC command registers with serial
communication operations (SCOMs) interpreted by the I2C slave. For the
P9 OCC, add a procedure to use the OCC in-kernel API to send a command
to the OCC through the SBE.

Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
---
 drivers/hwmon/occ/p8_i2c.c | 185 ++++++++++++++++++++++++++++++++++++++++++++-
 drivers/hwmon/occ/p9_sbe.c |  38 +++++++++-
 2 files changed, 221 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/occ/p8_i2c.c b/drivers/hwmon/occ/p8_i2c.c
index 899294b..9a920db 100644
--- a/drivers/hwmon/occ/p8_i2c.c
+++ b/drivers/hwmon/occ/p8_i2c.c
@@ -12,11 +12,29 @@
 
 #include <linux/device.h>
 #include <linux/errno.h>
+#include <linux/fsi-occ.h>
 #include <linux/i2c.h>
+#include <linux/jiffies.h>
 #include <linux/module.h>
+#include <linux/sched.h>
+#include <asm/unaligned.h>
 
 #include "common.h"
 
+#define OCC_TIMEOUT_MS			1000
+#define OCC_CMD_IN_PRG_WAIT_MS		50
+
+/* OCB (on-chip control bridge - interface to OCC) registers */
+#define OCB_DATA1			0x6B035
+#define OCB_ADDR			0x6B070
+#define OCB_DATA3			0x6B075
+
+/* OCC SRAM address space */
+#define OCC_SRAM_ADDR_CMD		0xFFFF6000
+#define OCC_SRAM_ADDR_RESP		0xFFFF7000
+
+#define OCC_DATA_ATTN			0x20010000
+
 struct p8_i2c_occ {
 	struct occ occ;
 	struct i2c_client *client;
@@ -24,9 +42,174 @@ struct p8_i2c_occ {
 
 #define to_p8_i2c_occ(x)	container_of((x), struct p8_i2c_occ, occ)
 
+static int p8_i2c_occ_getscom(struct i2c_client *client, u32 address, u8 *data)
+{
+	ssize_t rc;
+	__be64 buf;
+	struct i2c_msg msgs[2];
+
+	/* p8 i2c slave requires shift */
+	address <<= 1;
+
+	msgs[0].addr = client->addr;
+	msgs[0].flags = client->flags & I2C_M_TEN;
+	msgs[0].len = sizeof(u32);
+	/* address is a scom address; bus-endian */
+	msgs[0].buf = (char *)&address;
+
+	/* data from OCC is big-endian */
+	msgs[1].addr = client->addr;
+	msgs[1].flags = (client->flags & I2C_M_TEN) | I2C_M_RD;
+	msgs[1].len = sizeof(u64);
+	msgs[1].buf = (char *)&buf;
+
+	rc = i2c_transfer(client->adapter, msgs, 2);
+	if (rc < 0)
+		return rc;
+
+	*(u64 *)data = be64_to_cpu(buf);
+
+	return 0;
+}
+
+static int p8_i2c_occ_putscom(struct i2c_client *client, u32 address, u8 *data)
+{
+	u32 buf[3];
+	ssize_t rc;
+
+	/* p8 i2c slave requires shift */
+	address <<= 1;
+
+	/* address is bus-endian; data passed through from user as-is */
+	buf[0] = address;
+	memcpy(&buf[1], &data[4], sizeof(u32));
+	memcpy(&buf[2], data, sizeof(u32));
+
+	rc = i2c_master_send(client, (const char *)buf, sizeof(buf));
+	if (rc < 0)
+		return rc;
+	else if (rc != sizeof(buf))
+		return -EIO;
+
+	return 0;
+}
+
+static int p8_i2c_occ_putscom_u32(struct i2c_client *client, u32 address,
+				  u32 data0, u32 data1)
+{
+	u8 buf[8];
+
+	memcpy(buf, &data0, 4);
+	memcpy(buf + 4, &data1, 4);
+
+	return p8_i2c_occ_putscom(client, address, buf);
+}
+
+static int p8_i2c_occ_putscom_be(struct i2c_client *client, u32 address,
+				 u8 *data)
+{
+	__be32 data0, data1;
+
+	memcpy(&data0, data, 4);
+	memcpy(&data1, data + 4, 4);
+
+	return p8_i2c_occ_putscom_u32(client, address, be32_to_cpu(data0),
+				      be32_to_cpu(data1));
+}
+
 static int p8_i2c_occ_send_cmd(struct occ *occ, u8 *cmd)
 {
-	return -EOPNOTSUPP;
+	int i, rc;
+	unsigned long start;
+	u16 data_length;
+	const unsigned long timeout = msecs_to_jiffies(OCC_TIMEOUT_MS);
+	const long int wait_time = msecs_to_jiffies(OCC_CMD_IN_PRG_WAIT_MS);
+	struct p8_i2c_occ *ctx = to_p8_i2c_occ(occ);
+	struct i2c_client *client = ctx->client;
+	struct occ_response *resp = &occ->resp;
+
+	start = jiffies;
+
+	/* set sram address for command */
+	rc = p8_i2c_occ_putscom_u32(client, OCB_ADDR, OCC_SRAM_ADDR_CMD, 0);
+	if (rc)
+		return rc;
+
+	/* write command (expected to already be BE), we need bus-endian... */
+	rc = p8_i2c_occ_putscom_be(client, OCB_DATA3, cmd);
+	if (rc)
+		return rc;
+
+	/* trigger OCC attention */
+	rc = p8_i2c_occ_putscom_u32(client, OCB_DATA1, OCC_DATA_ATTN, 0);
+	if (rc)
+		return rc;
+
+	do {
+		/* set sram address for response */
+		rc = p8_i2c_occ_putscom_u32(client, OCB_ADDR,
+					    OCC_SRAM_ADDR_RESP, 0);
+		if (rc)
+			return rc;
+
+		rc = p8_i2c_occ_getscom(client, OCB_DATA3, (u8 *)resp);
+		if (rc)
+			return rc;
+
+		/* wait for OCC */
+		if (resp->return_status == OCC_RESP_CMD_IN_PRG) {
+			rc = -EALREADY;
+
+			if (time_after(jiffies, start + timeout))
+				break;
+
+			set_current_state(TASK_INTERRUPTIBLE);
+			schedule_timeout(wait_time);
+		}
+	} while (rc);
+
+	/* check the OCC response */
+	switch (resp->return_status) {
+	case OCC_RESP_CMD_IN_PRG:
+		rc = -ETIMEDOUT;
+		break;
+	case OCC_RESP_SUCCESS:
+		rc = 0;
+		break;
+	case OCC_RESP_CMD_INVAL:
+	case OCC_RESP_CMD_LEN_INVAL:
+	case OCC_RESP_DATA_INVAL:
+	case OCC_RESP_CHKSUM_ERR:
+		rc = -EINVAL;
+		break;
+	case OCC_RESP_INT_ERR:
+	case OCC_RESP_BAD_STATE:
+	case OCC_RESP_CRIT_EXCEPT:
+	case OCC_RESP_CRIT_INIT:
+	case OCC_RESP_CRIT_WATCHDOG:
+	case OCC_RESP_CRIT_OCB:
+	case OCC_RESP_CRIT_HW:
+		rc = -EREMOTEIO;
+		break;
+	default:
+		rc = -EPROTO;
+	}
+
+	if (rc < 0)
+		return rc;
+
+	data_length = get_unaligned_be16(&resp->data_length);
+	if (data_length > OCC_RESP_DATA_BYTES)
+		return -EMSGSIZE;
+
+	/* fetch the rest of the response data */
+	for (i = 8; i < data_length + 7; i += 8) {
+		rc = p8_i2c_occ_getscom(client, OCB_DATA3, ((u8 *)resp) + i);
+		if (rc)
+			return rc;
+	}
+
+	return 0;
 }
 
 static int p8_i2c_occ_probe(struct i2c_client *client,
diff --git a/drivers/hwmon/occ/p9_sbe.c b/drivers/hwmon/occ/p9_sbe.c
index 7c026a5..fb32788 100644
--- a/drivers/hwmon/occ/p9_sbe.c
+++ b/drivers/hwmon/occ/p9_sbe.c
@@ -12,6 +12,7 @@
 
 #include <linux/device.h>
 #include <linux/errno.h>
+#include <linux/fsi-occ.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 
@@ -26,7 +27,42 @@ struct p9_sbe_occ {
 
 static int p9_sbe_occ_send_cmd(struct occ *occ, u8 *cmd)
 {
-	return -EOPNOTSUPP;
+	struct occ_response *resp = &occ->resp;
+	struct p9_sbe_occ *ctx = to_p9_sbe_occ(occ);
+	size_t resp_len = sizeof(*resp);
+	int rc;
+
+	rc = fsi_occ_submit(ctx->sbe, cmd, 8, resp, &resp_len);
+	if (rc < 0)
+		return rc;
+
+	switch (resp->return_status) {
+	case OCC_RESP_CMD_IN_PRG:
+		rc = -ETIMEDOUT;
+		break;
+	case OCC_RESP_SUCCESS:
+		rc = 0;
+		break;
+	case OCC_RESP_CMD_INVAL:
+	case OCC_RESP_CMD_LEN_INVAL:
+	case OCC_RESP_DATA_INVAL:
+	case OCC_RESP_CHKSUM_ERR:
+		rc = -EINVAL;
+		break;
+	case OCC_RESP_INT_ERR:
+	case OCC_RESP_BAD_STATE:
+	case OCC_RESP_CRIT_EXCEPT:
+	case OCC_RESP_CRIT_INIT:
+	case OCC_RESP_CRIT_WATCHDOG:
+	case OCC_RESP_CRIT_OCB:
+	case OCC_RESP_CRIT_HW:
+		rc = -EREMOTEIO;
+		break;
+	default:
+		rc = -EPROTO;
+	}
+
+	return rc;
 }
 
 static int p9_sbe_occ_probe(struct platform_device *pdev)
-- 
1.8.3.1

[PATCH v4 6/9] hwmon (occ): Parse OCC poll response

[Eddie James]

Add method to parse the response from the OCC poll command. This only
needs to be done during probe(), since the OCC shouldn't change the
number or format of sensors while it's running. The parsed response
allows quick access to sensor data, as well as information on the
number and version of sensors, which we need to instantiate hwmon
attributes.

Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
---
 drivers/hwmon/occ/common.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++
 drivers/hwmon/occ/common.h | 55 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 116 insertions(+)

diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
index 1fd3453..73f62aa 100644
--- a/drivers/hwmon/occ/common.c
+++ b/drivers/hwmon/occ/common.c
@@ -11,6 +11,7 @@
  */
 
 #include <linux/device.h>
+#include <linux/kernel.h>
 
 #include "common.h"
 
@@ -32,6 +33,64 @@ static int occ_poll(struct occ *occ)
 	return occ->send_cmd(occ, cmd);
 }
 
+/* only need to do this once at startup, as OCC won't change sensors on us */
+static void occ_parse_poll_response(struct occ *occ)
+{
+	unsigned int i, old_offset, offset = 0, size = 0;
+	struct occ_sensor *sensor;
+	struct occ_sensors *sensors = &occ->sensors;
+	struct occ_response *resp = &occ->resp;
+	struct occ_poll_response *poll =
+		(struct occ_poll_response *)&resp->data[0];
+	struct occ_poll_response_header *header = &poll->header;
+	struct occ_sensor_data_block *block = &poll->block;
+
+	dev_info(occ->bus_dev, "OCC found, code level: %.16s\n",
+		 header->occ_code_level);
+
+	for (i = 0; i < header->num_sensor_data_blocks; ++i) {
+		block = (struct occ_sensor_data_block *)((u8 *)block + offset);
+		old_offset = offset;
+		offset = (block->header.num_sensors *
+			  block->header.sensor_length) + sizeof(block->header);
+		size += offset;
+
+		/* validate all the length/size fields */
+		if ((size + sizeof(*header)) >= OCC_RESP_DATA_BYTES) {
+			dev_warn(occ->bus_dev, "exceeded response buffer\n");
+			return;
+		}
+
+		dev_dbg(occ->bus_dev, " %04x..%04x: %.4s (%d sensors)\n",
+			old_offset, offset - 1, block->header.eye_catcher,
+			block->header.num_sensors);
+
+		/* match sensor block type */
+		if (strncmp(block->header.eye_catcher, "TEMP", 4) == 0)
+			sensor = &sensors->temp;
+		else if (strncmp(block->header.eye_catcher, "FREQ", 4) == 0)
+			sensor = &sensors->freq;
+		else if (strncmp(block->header.eye_catcher, "POWR", 4) == 0)
+			sensor = &sensors->power;
+		else if (strncmp(block->header.eye_catcher, "CAPS", 4) == 0)
+			sensor = &sensors->caps;
+		else if (strncmp(block->header.eye_catcher, "EXTN", 4) == 0)
+			sensor = &sensors->extended;
+		else {
+			dev_warn(occ->bus_dev, "sensor not supported %.4s\n",
+				 block->header.eye_catcher);
+			continue;
+		}
+
+		sensor->num_sensors = block->header.num_sensors;
+		sensor->version = block->header.sensor_format;
+		sensor->data = &block->data;
+	}
+
+	dev_dbg(occ->bus_dev, "Max resp size: %u+%zd=%zd\n", size,
+		sizeof(*header), size + sizeof(*header));
+}
+
 int occ_setup(struct occ *occ, const char *name)
 {
 	int rc;
@@ -46,5 +105,7 @@ int occ_setup(struct occ *occ, const char *name)
 		return rc;
 	}
 
+	occ_parse_poll_response(occ);
+
 	return 0;
 }
diff --git a/drivers/hwmon/occ/common.h b/drivers/hwmon/occ/common.h
index 775b421..cfcd353 100644
--- a/drivers/hwmon/occ/common.h
+++ b/drivers/hwmon/occ/common.h
@@ -29,10 +29,65 @@ struct occ_response {
 	__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;
+};
+
 struct occ {
 	struct device *bus_dev;
 
 	struct occ_response resp;
+	struct occ_sensors sensors;
 
 	u8 poll_cmd_data;		/* to perform OCC poll command */
 	int (*send_cmd)(struct occ *occ, u8 *cmd);
-- 
1.8.3.1

[PATCH v4 7/9] hwmon (occ): Add sensor types and versions

[Eddie James]

Add structures to define all sensor types and versions. Add sysfs show
and store functions for each sensor type. Add a method to construct the
"set user power cap" command and send it to the OCC. Add rate limit to
polling the OCC (in case user-space reads our hwmon entries rapidly).

Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
---
 drivers/hwmon/occ/common.c | 648 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/hwmon/occ/common.h |   5 +
 2 files changed, 653 insertions(+)

diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
index 73f62aa..1719536 100644
--- a/drivers/hwmon/occ/common.c
+++ b/drivers/hwmon/occ/common.c
@@ -11,10 +11,119 @@
  */
 
 #include <linux/device.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/jiffies.h>
 #include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <asm/unaligned.h>
 
 #include "common.h"
 
+#define OCC_UPDATE_FREQUENCY		msecs_to_jiffies(1000)
+
+#define OCC_TEMP_SENSOR_FAULT		0xFF
+
+#define OCC_FRU_TYPE_VRM		0x3
+
+/* OCC sensor type and version definitions */
+
+struct temp_sensor_1 {
+	u16 sensor_id;
+	u16 value;
+} __packed;
+
+struct temp_sensor_2 {
+	u32 sensor_id;
+	u8 fru_type;
+	u8 value;
+} __packed;
+
+struct freq_sensor_1 {
+	u16 sensor_id;
+	u16 value;
+} __packed;
+
+struct freq_sensor_2 {
+	u32 sensor_id;
+	u16 value;
+} __packed;
+
+struct power_sensor_1 {
+	u16 sensor_id;
+	u32 update_tag;
+	u32 accumulator;
+	u16 value;
+} __packed;
+
+struct power_sensor_2 {
+	u32 sensor_id;
+	u8 function_id;
+	u8 apss_channel;
+	u16 reserved;
+	u32 update_tag;
+	u64 accumulator;
+	u16 value;
+} __packed;
+
+struct power_sensor_data {
+	u16 value;
+	u32 update_tag;
+	u64 accumulator;
+} __packed;
+
+struct power_sensor_data_and_time {
+	u16 update_time;
+	u16 value;
+	u32 update_tag;
+	u64 accumulator;
+} __packed;
+
+struct power_sensor_a0 {
+	u32 sensor_id;
+	struct power_sensor_data_and_time system;
+	u32 reserved;
+	struct power_sensor_data_and_time proc;
+	struct power_sensor_data vdd;
+	struct power_sensor_data vdn;
+} __packed;
+
+struct caps_sensor_1 {
+	u16 curr_powercap;
+	u16 curr_powerreading;
+	u16 norm_powercap;
+	u16 max_powercap;
+	u16 min_powercap;
+	u16 user_powerlimit;
+} __packed;
+
+struct caps_sensor_2 {
+	u16 curr_powercap;
+	u16 curr_powerreading;
+	u16 norm_powercap;
+	u16 max_powercap;
+	u16 min_powercap;
+	u16 user_powerlimit;
+	u8 user_powerlimit_source;
+} __packed;
+
+struct caps_sensor_3 {
+	u16 curr_powercap;
+	u16 curr_powerreading;
+	u16 norm_powercap;
+	u16 max_powercap;
+	u16 hard_min_powercap;
+	u16 soft_min_powercap;
+	u16 user_powerlimit;
+	u8 user_powerlimit_source;
+} __packed;
+
+struct extended_sensor {
+	u8 name[4];
+	u8 flags;
+	u8 reserved;
+	u8 data[6];
+} __packed;
+
 static int occ_poll(struct occ *occ)
 {
 	u16 checksum = occ->poll_cmd_data + 1;
@@ -30,9 +139,545 @@ static int occ_poll(struct occ *occ)
 	cmd[6] = checksum & 0xFF;	/* checksum lsb */
 	cmd[7] = 0;
 
+	/* mutex should already be locked if necessary */
 	return occ->send_cmd(occ, cmd);
 }
 
+static int occ_set_user_power_cap(struct occ *occ, u16 user_power_cap)
+{
+	int rc;
+	u8 cmd[8];
+	u16 checksum = 0x24;
+	__be16 user_power_cap_be = cpu_to_be16(user_power_cap);
+
+	cmd[0] = 0;
+	cmd[1] = 0x22;
+	cmd[2] = 0;
+	cmd[3] = 2;
+
+	memcpy(&cmd[4], &user_power_cap_be, 2);
+
+	checksum += cmd[4] + cmd[5];
+	cmd[6] = checksum >> 8;
+	cmd[7] = checksum & 0xFF;
+
+	rc = mutex_lock_interruptible(&occ->lock);
+	if (rc)
+		return rc;
+
+	rc = occ->send_cmd(occ, cmd);
+
+	mutex_unlock(&occ->lock);
+
+	return rc;
+}
+
+static int occ_update_response(struct occ *occ)
+{
+	int rc = mutex_lock_interruptible(&occ->lock);
+
+	if (rc)
+		return rc;
+
+	/* limit the maximum rate of polling the OCC */
+	if (time_after(jiffies, occ->last_update + OCC_UPDATE_FREQUENCY)) {
+		rc = occ_poll(occ);
+		occ->last_update = jiffies;
+	}
+
+	mutex_unlock(&occ->lock);
+	return rc;
+}
+
+static ssize_t occ_show_temp_1(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	int rc;
+	u32 val = 0;
+	struct temp_sensor_1 *temp;
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_sensors *sensors = &occ->sensors;
+	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+
+	rc = occ_update_response(occ);
+	if (rc)
+		return rc;
+
+	temp = ((struct temp_sensor_1 *)sensors->temp.data) + sattr->index;
+
+	switch (sattr->nr) {
+	case 0:
+		val = get_unaligned_be16(&temp->sensor_id);
+		break;
+	case 1:
+		/* millidegrees */
+		val = get_unaligned_be16(&temp->value) * 1000;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return snprintf(buf, PAGE_SIZE - 1, "%u\n", val);
+}
+
+static ssize_t occ_show_temp_2(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	int rc;
+	u32 val = 0;
+	struct temp_sensor_2 *temp;
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_sensors *sensors = &occ->sensors;
+	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+
+	rc = occ_update_response(occ);
+	if (rc)
+		return rc;
+
+	temp = ((struct temp_sensor_2 *)sensors->temp.data) + sattr->index;
+
+	switch (sattr->nr) {
+	case 0:
+		val = get_unaligned_be32(&temp->sensor_id);
+		break;
+	case 1:
+		val = temp->value;
+		if (val == OCC_TEMP_SENSOR_FAULT)
+			return -EREMOTEIO;
+
+		if (temp->fru_type != OCC_FRU_TYPE_VRM) {
+			/* sensor not ready */
+			if (val == 0)
+				return -EAGAIN;
+
+			val *= 1000;	/* millidegrees */
+		}
+		break;
+	case 2:
+		val = temp->fru_type;
+		break;
+	case 3:
+		val = temp->value == OCC_TEMP_SENSOR_FAULT;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return snprintf(buf, PAGE_SIZE - 1, "%u\n", val);
+}
+
+static ssize_t occ_show_freq_1(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	int rc;
+	u16 val = 0;
+	struct freq_sensor_1 *freq;
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_sensors *sensors = &occ->sensors;
+	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+
+	rc = occ_update_response(occ);
+	if (rc)
+		return rc;
+
+	freq = ((struct freq_sensor_1 *)sensors->freq.data) + sattr->index;
+
+	switch (sattr->nr) {
+	case 0:
+		val = get_unaligned_be16(&freq->sensor_id);
+		break;
+	case 1:
+		val = get_unaligned_be16(&freq->value);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return snprintf(buf, PAGE_SIZE - 1, "%u\n", val);
+}
+
+static ssize_t occ_show_freq_2(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	int rc;
+	u32 val = 0;
+	struct freq_sensor_2 *freq;
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_sensors *sensors = &occ->sensors;
+	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+
+	rc = occ_update_response(occ);
+	if (rc)
+		return rc;
+
+	freq = ((struct freq_sensor_2 *)sensors->freq.data) + sattr->index;
+
+	switch (sattr->nr) {
+	case 0:
+		val = get_unaligned_be32(&freq->sensor_id);
+		break;
+	case 1:
+		val = get_unaligned_be16(&freq->value);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return snprintf(buf, PAGE_SIZE - 1, "%u\n", val);
+}
+
+static ssize_t occ_show_power_1(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	int rc;
+	u64 val = 0;
+	struct power_sensor_1 *power;
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_sensors *sensors = &occ->sensors;
+	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+
+	rc = occ_update_response(occ);
+	if (rc)
+		return rc;
+
+	power = ((struct power_sensor_1 *)sensors->power.data) + sattr->index;
+
+	switch (sattr->nr) {
+	case 0:
+		val = get_unaligned_be16(&power->sensor_id);
+		break;
+	case 1:
+		val = get_unaligned_be32(&power->update_tag);
+		break;
+	case 2:
+		val = get_unaligned_be32(&power->accumulator);
+		break;
+	case 3:
+		/* microwatts */
+		val = get_unaligned_be16(&power->value) * 1000000ULL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return snprintf(buf, PAGE_SIZE - 1, "%llu\n", val);
+}
+
+static ssize_t occ_show_power_2(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	int rc;
+	u64 val = 0;
+	struct power_sensor_2 *power;
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_sensors *sensors = &occ->sensors;
+	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+
+	rc = occ_update_response(occ);
+	if (rc)
+		return rc;
+
+	power = ((struct power_sensor_2 *)sensors->power.data) + sattr->index;
+
+	switch (sattr->nr) {
+	case 0:
+		val = get_unaligned_be32(&power->sensor_id);
+		break;
+	case 1:
+		val = get_unaligned_be32(&power->update_tag);
+		break;
+	case 2:
+		val = get_unaligned_be64(&power->accumulator);
+		break;
+	case 3:
+		/* microwatts */
+		val = get_unaligned_be16(&power->value) * 1000000ULL;
+		break;
+	case 4:
+		val = power->function_id;
+		break;
+	case 5:
+		val = power->apss_channel;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return snprintf(buf, PAGE_SIZE - 1, "%llu\n", val);
+}
+
+static ssize_t occ_show_power_a0(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	int rc;
+	u64 val = 0;
+	struct power_sensor_a0 *power;
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_sensors *sensors = &occ->sensors;
+	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+
+	rc = occ_update_response(occ);
+	if (rc)
+		return rc;
+
+	power = ((struct power_sensor_a0 *)sensors->power.data) + sattr->index;
+
+	switch (sattr->nr) {
+	case 0:
+		val = get_unaligned_be32(&power->sensor_id);
+		break;
+	case 1:
+		return snprintf(buf, PAGE_SIZE - 1, "system\n");
+	case 2:
+		val = get_unaligned_be16(&power->system.update_time);
+		break;
+	case 3:
+		/* microwatts */
+		val = get_unaligned_be16(&power->system.value) * 1000000ULL;
+		break;
+	case 4:
+		val = get_unaligned_be32(&power->system.update_tag);
+		break;
+	case 5:
+		val = get_unaligned_be64(&power->system.accumulator);
+		break;
+	case 6:
+		return snprintf(buf, PAGE_SIZE - 1, "proc\n");
+	case 7:
+		val = get_unaligned_be16(&power->proc.update_time);
+		break;
+	case 8:
+		/* microwatts */
+		val = get_unaligned_be16(&power->proc.value) * 1000000ULL;
+		break;
+	case 9:
+		val = get_unaligned_be32(&power->proc.update_tag);
+		break;
+	case 10:
+		val = get_unaligned_be64(&power->proc.accumulator);
+		break;
+	case 11:
+		return snprintf(buf, PAGE_SIZE - 1, "vdd\n");
+	case 12:
+		/* microwatts */
+		val = get_unaligned_be16(&power->vdd.value) * 1000000ULL;
+		break;
+	case 13:
+		val = get_unaligned_be32(&power->vdd.update_tag);
+		break;
+	case 14:
+		val = get_unaligned_be64(&power->vdd.accumulator);
+		break;
+	case 15:
+		return snprintf(buf, PAGE_SIZE - 1, "vdn\n");
+	case 16:
+		/* microwatts */
+		val = get_unaligned_be16(&power->vdn.value) * 1000000ULL;
+		break;
+	case 17:
+		val = get_unaligned_be32(&power->vdn.update_tag);
+		break;
+	case 18:
+		val = get_unaligned_be64(&power->vdn.accumulator);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return snprintf(buf, PAGE_SIZE - 1, "%llu\n", val);
+}
+
+static ssize_t occ_show_caps_1(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	int rc;
+	u16 val = 0;
+	struct caps_sensor_1 *caps;
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_sensors *sensors = &occ->sensors;
+	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+
+	rc = occ_update_response(occ);
+	if (rc)
+		return rc;
+
+	caps = ((struct caps_sensor_1 *)sensors->caps.data) + sattr->index;
+
+	switch (sattr->nr) {
+	case 0:
+		val = get_unaligned_be16(&caps->curr_powercap);
+		break;
+	case 1:
+		val = get_unaligned_be16(&caps->curr_powerreading);
+		break;
+	case 2:
+		val = get_unaligned_be16(&caps->norm_powercap);
+		break;
+	case 3:
+		val = get_unaligned_be16(&caps->max_powercap);
+		break;
+	case 4:
+		val = get_unaligned_be16(&caps->min_powercap);
+		break;
+	case 5:
+		val = get_unaligned_be16(&caps->user_powerlimit);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return snprintf(buf, PAGE_SIZE - 1, "%u\n", val);
+}
+
+static ssize_t occ_show_caps_2(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	int rc;
+	u16 val = 0;
+	struct caps_sensor_2 *caps;
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_sensors *sensors = &occ->sensors;
+	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+
+	rc = occ_update_response(occ);
+	if (rc)
+		return rc;
+
+	caps = ((struct caps_sensor_2 *)sensors->caps.data) + sattr->index;
+
+	switch (sattr->nr) {
+	case 0:
+		val = get_unaligned_be16(&caps->curr_powercap);
+		break;
+	case 1:
+		val = get_unaligned_be16(&caps->curr_powerreading);
+		break;
+	case 2:
+		val = get_unaligned_be16(&caps->norm_powercap);
+		break;
+	case 3:
+		val = get_unaligned_be16(&caps->max_powercap);
+		break;
+	case 4:
+		val = get_unaligned_be16(&caps->min_powercap);
+		break;
+	case 5:
+		val = get_unaligned_be16(&caps->user_powerlimit);
+		break;
+	case 6:
+		val = caps->user_powerlimit_source;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return snprintf(buf, PAGE_SIZE - 1, "%u\n", val);
+}
+
+static ssize_t occ_show_caps_3(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	int rc;
+	u16 val = 0;
+	struct caps_sensor_3 *caps;
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_sensors *sensors = &occ->sensors;
+	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+
+	rc = occ_update_response(occ);
+	if (rc)
+		return rc;
+
+	caps = ((struct caps_sensor_3 *)sensors->caps.data) + sattr->index;
+
+	switch (sattr->nr) {
+	case 0:
+		val = get_unaligned_be16(&caps->curr_powercap);
+		break;
+	case 1:
+		val = get_unaligned_be16(&caps->curr_powerreading);
+		break;
+	case 2:
+		val = get_unaligned_be16(&caps->norm_powercap);
+		break;
+	case 3:
+		val = get_unaligned_be16(&caps->max_powercap);
+		break;
+	case 4:
+		val = get_unaligned_be16(&caps->hard_min_powercap);
+		break;
+	case 5:
+		val = get_unaligned_be16(&caps->user_powerlimit);
+		break;
+	case 6:
+		val = caps->user_powerlimit_source;
+		break;
+	case 7:
+		val = get_unaligned_be16(&caps->soft_min_powercap);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return snprintf(buf, PAGE_SIZE - 1, "%u\n", val);
+}
+
+static ssize_t occ_store_caps_user(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t count)
+{
+	int rc;
+	u16 user_power_cap;
+	struct occ *occ = dev_get_drvdata(dev);
+
+	rc = kstrtou16(buf, 0, &user_power_cap);
+	if (rc)
+		return rc;
+
+	rc = occ_set_user_power_cap(occ, user_power_cap);
+	if (rc)
+		return rc;
+
+	return count;
+}
+
+static ssize_t occ_show_extended(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	int rc;
+	struct extended_sensor *extn;
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_sensors *sensors = &occ->sensors;
+	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+
+	rc = occ_update_response(occ);
+	if (rc)
+		return rc;
+
+	extn = ((struct extended_sensor *)sensors->extended.data) +
+		sattr->index;
+
+	switch (sattr->nr) {
+	case 0:
+		rc = snprintf(buf, PAGE_SIZE - 1, "%02x%02x%02x%02x\n",
+			      extn->name[0], extn->name[1], extn->name[2],
+			      extn->name[3]);
+		break;
+	case 1:
+		rc = snprintf(buf, PAGE_SIZE - 1, "%02x\n", extn->flags);
+		break;
+	case 2:
+		rc = snprintf(buf, PAGE_SIZE - 1, "%02x%02x%02x%02x%02x%02x\n",
+			      extn->data[0], extn->data[1], extn->data[2],
+			      extn->data[3], extn->data[4], extn->data[5]);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return rc;
+}
+
 /* only need to do this once at startup, as OCC won't change sensors on us */
 static void occ_parse_poll_response(struct occ *occ)
 {
@@ -95,6 +740,9 @@ int occ_setup(struct occ *occ, const char *name)
 {
 	int rc;
 
+	mutex_init(&occ->lock);
+
+	/* no need to lock */
 	rc = occ_poll(occ);
 	if (rc == -ESHUTDOWN) {
 		dev_info(occ->bus_dev, "host is not ready\n");
diff --git a/drivers/hwmon/occ/common.h b/drivers/hwmon/occ/common.h
index cfcd353..f697adb 100644
--- a/drivers/hwmon/occ/common.h
+++ b/drivers/hwmon/occ/common.h
@@ -12,6 +12,8 @@
 #ifndef OCC_COMMON_H
 #define OCC_COMMON_H
 
+#include <linux/mutex.h>
+
 struct device;
 
 #define OCC_RESP_DATA_BYTES		4089
@@ -91,6 +93,9 @@ struct occ {
 
 	u8 poll_cmd_data;		/* to perform OCC poll command */
 	int (*send_cmd)(struct occ *occ, u8 *cmd);
+
+	unsigned long last_update;
+	struct mutex lock;		/* lock OCC access */
 };
 
 int occ_setup(struct occ *occ, const char *name);
-- 
1.8.3.1

[PATCH v4 8/9] hwmon (occ): Add sensor attributes and register hwmon device

[Eddie James]

Setup the sensor attributes for every OCC sensor found by the first poll
response. Register the attributes with hwmon.

Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
---
 drivers/hwmon/occ/common.c | 452 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/hwmon/occ/common.h |  16 ++
 2 files changed, 468 insertions(+)

diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
index 1719536..da55919 100644
--- a/drivers/hwmon/occ/common.c
+++ b/drivers/hwmon/occ/common.c
@@ -11,10 +11,12 @@
  */
 
 #include <linux/device.h>
+#include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/mutex.h>
+#include <linux/sysfs.h>
 #include <asm/unaligned.h>
 
 #include "common.h"
@@ -678,6 +680,439 @@ static ssize_t occ_show_extended(struct device *dev,
 	return rc;
 }
 
+/*
+ * Some helper macros to make it easier to define an occ_attribute. Since these
+ * are dynamically allocated, we shouldn't use the existing kernel macros which
+ * stringify the name argument.
+ */
+#define ATTR_OCC(_name, _mode, _show, _store) {				\
+	.attr	= {							\
+		.name = _name,						\
+		.mode = VERIFY_OCTAL_PERMISSIONS(_mode),		\
+	},								\
+	.show	= _show,						\
+	.store	= _store,						\
+}
+
+#define SENSOR_ATTR_OCC(_name, _mode, _show, _store, _nr, _index) {	\
+	.dev_attr	= ATTR_OCC(_name, _mode, _show, _store),	\
+	.index		= _index,					\
+	.nr		= _nr,						\
+}
+
+#define OCC_INIT_ATTR(_name, _mode, _show, _store, _nr, _index)		\
+	((struct sensor_device_attribute_2)				\
+		SENSOR_ATTR_OCC(_name, _mode, _show, _store, _nr, _index))
+
+/*
+ * Allocate and instatiate sensor_device_attribute_2s. It's most efficient to
+ * use our own instead of the built-in hwmon attribute types.
+ */
+static int occ_setup_sensor_attrs(struct occ *occ)
+{
+	unsigned int i, s, num_attrs = 0;
+	struct device *dev = occ->bus_dev;
+	struct occ_sensors *sensors = &occ->sensors;
+	struct occ_attribute *attr;
+	struct temp_sensor_2 *temp;
+	ssize_t (*show_temp)(struct device *, struct device_attribute *,
+			     char *) = occ_show_temp_1;
+	ssize_t (*show_freq)(struct device *, struct device_attribute *,
+			     char *) = occ_show_freq_1;
+	ssize_t (*show_power)(struct device *, struct device_attribute *,
+			      char *) = occ_show_power_1;
+	ssize_t (*show_caps)(struct device *, struct device_attribute *,
+			     char *) = occ_show_caps_1;
+
+	switch (sensors->temp.version) {
+	case 1:
+		num_attrs += (sensors->temp.num_sensors * 2);
+		break;
+	case 2:
+		num_attrs += (sensors->temp.num_sensors * 4);
+		show_temp = occ_show_temp_2;
+		break;
+	default:
+		sensors->temp.num_sensors = 0;
+	}
+
+	switch (sensors->freq.version) {
+	case 2:
+		show_freq = occ_show_freq_2;
+		/* fall through */
+	case 1:
+		num_attrs += (sensors->freq.num_sensors * 2);
+		break;
+	default:
+		sensors->freq.num_sensors = 0;
+	}
+
+	switch (sensors->power.version) {
+	case 1:
+		num_attrs += (sensors->power.num_sensors * 4);
+		break;
+	case 2:
+		num_attrs += (sensors->power.num_sensors * 6);
+		show_power = occ_show_power_2;
+		break;
+	case 0xA0:
+		num_attrs += (sensors->power.num_sensors * 19);
+		show_power = occ_show_power_a0;
+		break;
+	default:
+		sensors->power.num_sensors = 0;
+	}
+
+	switch (sensors->caps.version) {
+	case 1:
+		num_attrs += (sensors->caps.num_sensors * 6);
+		break;
+	case 2:
+		num_attrs += (sensors->caps.num_sensors * 7);
+		show_caps = occ_show_caps_2;
+		break;
+	case 3:
+		num_attrs += (sensors->caps.num_sensors * 8);
+		show_caps = occ_show_caps_3;
+		break;
+	default:
+		sensors->caps.num_sensors = 0;
+	}
+
+	switch (sensors->extended.version) {
+	case 1:
+		num_attrs += (sensors->extended.num_sensors * 3);
+		break;
+	default:
+		sensors->extended.num_sensors = 0;
+	}
+
+	occ->attrs = devm_kzalloc(dev, sizeof(*occ->attrs) * num_attrs,
+				  GFP_KERNEL);
+	if (!occ->attrs)
+		return -ENOMEM;
+
+	/* null-terminated list */
+	occ->group.attrs = devm_kzalloc(dev, sizeof(*occ->group.attrs) *
+					num_attrs + 1, GFP_KERNEL);
+	if (!occ->group.attrs)
+		return -ENOMEM;
+
+	attr = occ->attrs;
+
+	for (i = 0; i < sensors->temp.num_sensors; ++i) {
+		s = i + 1;
+		temp = ((struct temp_sensor_2 *)sensors->temp.data) + i;
+
+		snprintf(attr->name, sizeof(attr->name), "temp%d_label", s);
+		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_temp, NULL,
+					     0, i);
+		attr++;
+
+		if (sensors->temp.version > 1 &&
+		    temp->fru_type == OCC_FRU_TYPE_VRM) {
+			snprintf(attr->name, sizeof(attr->name),
+				 "temp%d_alarm", s);
+		} else {
+			snprintf(attr->name, sizeof(attr->name),
+				 "temp%d_input", s);
+		}
+
+		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_temp, NULL,
+					     1, i);
+		attr++;
+
+		if (sensors->temp.version > 1) {
+			snprintf(attr->name, sizeof(attr->name),
+				 "temp%d_fru_type", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_temp, NULL, 2, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "temp%d_fault", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_temp, NULL, 3, i);
+			attr++;
+		}
+	}
+
+	for (i = 0; i < sensors->freq.num_sensors; ++i) {
+		s = i + 1;
+
+		snprintf(attr->name, sizeof(attr->name), "freq%d_label", s);
+		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_freq, NULL,
+					     0, i);
+		attr++;
+
+		snprintf(attr->name, sizeof(attr->name), "freq%d_input", s);
+		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_freq, NULL,
+					     1, i);
+		attr++;
+	}
+
+	if (sensors->power.version == 0xA0) {
+		/* Special case for many-attribute power sensor. Split it into
+		 * a sensor number per power type, emulating several sensors.
+		 */
+		for (i = 0; i < sensors->power.num_sensors; ++i) {
+			s = (i * 4) + 1;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_id", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 0, i);
+			attr++;
+
+			/* system power attributes */
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_label", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 1, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_update_time", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 2, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_input", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 3, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_update_tag", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 4, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_accumulator", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 5, i);
+			attr++;
+
+			s++;
+
+			/* processor power attributes */
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_label", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 6, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_update_time", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 7, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_input", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 8, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_update_tag", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 9, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_accumulator", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 10, i);
+			attr++;
+
+			s++;
+
+			/* vdd power attributes */
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_label", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 11, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_input", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 12, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_update_tag", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 13, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_accumulator", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 14, i);
+			attr++;
+
+			s++;
+
+			/* vdn power attributes */
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_label", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 15, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_input", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 16, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_update_tag", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 17, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_accumulator", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 18, i);
+			attr++;
+		}
+	} else {
+		for (i = 0; i < sensors->power.num_sensors; ++i) {
+			s = i + 1;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_label", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 0, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_update_tag", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 1, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_accumulator", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 2, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "power%d_input", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_power, NULL, 3, i);
+			attr++;
+
+			if (sensors->power.version > 1) {
+				snprintf(attr->name, sizeof(attr->name),
+					 "power%d_function_id", s);
+				attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+							     show_power, NULL,
+							     4, i);
+				attr++;
+
+				snprintf(attr->name, sizeof(attr->name),
+					 "power%d_apss_channel", s);
+				attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+							     show_power, NULL,
+							     5, i);
+				attr++;
+			}
+		}
+	}
+
+	for (i = 0; i < sensors->caps.num_sensors; ++i) {
+		s = i + 1;
+
+		snprintf(attr->name, sizeof(attr->name), "caps%d_current", s);
+		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_caps, NULL,
+					     0, i);
+		attr++;
+
+		snprintf(attr->name, sizeof(attr->name), "caps%d_reading", s);
+		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_caps, NULL,
+					     1, i);
+		attr++;
+
+		snprintf(attr->name, sizeof(attr->name), "caps%d_norm", s);
+		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_caps, NULL,
+					     2, i);
+		attr++;
+
+		snprintf(attr->name, sizeof(attr->name), "caps%d_max", s);
+		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_caps, NULL,
+					     3, i);
+		attr++;
+
+		if (sensors->caps.version > 2) {
+			snprintf(attr->name, sizeof(attr->name),
+				 "caps%d_min_hard", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_caps, NULL, 4, i);
+			attr++;
+
+			snprintf(attr->name, sizeof(attr->name),
+				 "caps%d_min_soft", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_caps, NULL, 7, i);
+			attr++;
+		} else {
+			snprintf(attr->name, sizeof(attr->name), "caps%d_min",
+				 s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_caps, NULL, 4, i);
+			attr++;
+		}
+
+		snprintf(attr->name, sizeof(attr->name), "caps%d_user", s);
+		attr->sensor = OCC_INIT_ATTR(attr->name, 0644, show_caps,
+					     occ_store_caps_user, 5, i);
+		attr++;
+
+		if (sensors->caps.version > 1) {
+			snprintf(attr->name, sizeof(attr->name),
+				 "caps%d_user_source", s);
+			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+						     show_caps, NULL, 6, i);
+			attr++;
+		}
+	}
+
+	for (i = 0; i < sensors->extended.num_sensors; ++i) {
+		s = i + 1;
+
+		snprintf(attr->name, sizeof(attr->name), "extn%d_label", s);
+		attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+					     occ_show_extended, NULL, 0, i);
+		attr++;
+
+		snprintf(attr->name, sizeof(attr->name), "extn%d_flags", s);
+		attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+					     occ_show_extended, NULL, 1, i);
+		attr++;
+
+		snprintf(attr->name, sizeof(attr->name), "extn%d_input", s);
+		attr->sensor = OCC_INIT_ATTR(attr->name, 0444,
+					     occ_show_extended, NULL, 2, i);
+		attr++;
+	}
+
+	/* put the sensors in the group */
+	for (i = 0; i < num_attrs; ++i) {
+		sysfs_attr_init(&occ->attrs[i].sensor.dev_attr.attr);
+		occ->group.attrs[i] = &occ->attrs[i].sensor.dev_attr.attr;
+	}
+
+	return 0;
+}
+
 /* only need to do this once at startup, as OCC won't change sensors on us */
 static void occ_parse_poll_response(struct occ *occ)
 {
@@ -741,6 +1176,7 @@ int occ_setup(struct occ *occ, const char *name)
 	int rc;
 
 	mutex_init(&occ->lock);
+	occ->groups[0] = &occ->group;
 
 	/* no need to lock */
 	rc = occ_poll(occ);
@@ -755,5 +1191,21 @@ int occ_setup(struct occ *occ, const char *name)
 
 	occ_parse_poll_response(occ);
 
+	rc = occ_setup_sensor_attrs(occ);
+	if (rc) {
+		dev_err(occ->bus_dev, "failed to setup sensor attrs: %d\n",
+			rc);
+		return rc;
+	}
+
+	occ->hwmon = devm_hwmon_device_register_with_groups(occ->bus_dev, name,
+							    occ, occ->groups);
+	if (IS_ERR(occ->hwmon)) {
+		rc = PTR_ERR(occ->hwmon);
+		dev_err(occ->bus_dev, "failed to register hwmon device: %d\n",
+			rc);
+		return rc;
+	}
+
 	return 0;
 }
diff --git a/drivers/hwmon/occ/common.h b/drivers/hwmon/occ/common.h
index f697adb..2c1c06e 100644
--- a/drivers/hwmon/occ/common.h
+++ b/drivers/hwmon/occ/common.h
@@ -12,7 +12,9 @@
 #ifndef OCC_COMMON_H
 #define OCC_COMMON_H
 
+#include <linux/hwmon-sysfs.h>
 #include <linux/mutex.h>
+#include <linux/sysfs.h>
 
 struct device;
 
@@ -85,6 +87,15 @@ struct occ_sensors {
 	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;
 
@@ -96,6 +107,11 @@ struct occ {
 
 	unsigned long last_update;
 	struct mutex lock;		/* lock OCC access */
+
+	struct device *hwmon;
+	struct occ_attribute *attrs;
+	struct attribute_group group;
+	const struct attribute_group *groups[2];
 };
 
 int occ_setup(struct occ *occ, const char *name);
-- 
1.8.3.1

[PATCH v4 9/9] hwmon (occ): Add sysfs attributes for additional OCC data

[Eddie James]

The OCC provides a variety of additional information about the state of
the host processor, such as throttling, error conditions, and the number
of OCCs detected in the system. This information is essential to service
processor applications such as fan control and host management.
Therefore, export this data in the form of sysfs attributes attached to
the platform device (to which the hwmon device is also attached).

Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
---
 drivers/hwmon/occ/Makefile |   2 +-
 drivers/hwmon/occ/common.c |  45 ++++++++++-
 drivers/hwmon/occ/common.h |  17 ++++
 drivers/hwmon/occ/p8_i2c.c |  10 +++
 drivers/hwmon/occ/p9_sbe.c |   1 +
 drivers/hwmon/occ/sysfs.c  | 188 +++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 259 insertions(+), 4 deletions(-)
 create mode 100644 drivers/hwmon/occ/sysfs.c

diff --git a/drivers/hwmon/occ/Makefile b/drivers/hwmon/occ/Makefile
index ab5c3e9..46a8636 100644
--- a/drivers/hwmon/occ/Makefile
+++ b/drivers/hwmon/occ/Makefile
@@ -1,4 +1,4 @@
-occ-hwmon-objs := common.o
+occ-hwmon-objs := common.o sysfs.o
 
 ifeq ($(CONFIG_SENSORS_OCC_P9_SBE), y)
 occ-hwmon-objs += p9_sbe.o
diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
index da55919..7bc52af 100644
--- a/drivers/hwmon/occ/common.c
+++ b/drivers/hwmon/occ/common.c
@@ -21,6 +21,11 @@
 
 #include "common.h"
 
+#define OCC_ERROR_COUNT_THRESHOLD	2	/* required by OCC spec */
+
+#define OCC_STATE_SAFE			4
+#define OCC_SAFE_TIMEOUT		msecs_to_jiffies(60000) /* 1 min */
+
 #define OCC_UPDATE_FREQUENCY		msecs_to_jiffies(1000)
 
 #define OCC_TEMP_SENSOR_FAULT		0xFF
@@ -128,8 +133,10 @@ struct extended_sensor {
 
 static int occ_poll(struct occ *occ)
 {
+	int rc;
 	u16 checksum = occ->poll_cmd_data + 1;
 	u8 cmd[8];
+	struct occ_poll_response_header *header;
 
 	/* big endian */
 	cmd[0] = 0;			/* sequence number */
@@ -142,7 +149,35 @@ static int occ_poll(struct occ *occ)
 	cmd[7] = 0;
 
 	/* mutex should already be locked if necessary */
-	return occ->send_cmd(occ, cmd);
+	rc = occ->send_cmd(occ, cmd);
+	if (rc) {
+		if (occ->error_count++ > OCC_ERROR_COUNT_THRESHOLD)
+			occ->error = rc;
+
+		goto done;
+	}
+
+	/* clear error since communication was successful */
+	occ->error_count = 0;
+	occ->error = 0;
+
+	/* check for safe state */
+	header = (struct occ_poll_response_header *)occ->resp.data;
+	if (header->occ_state == OCC_STATE_SAFE) {
+		if (occ->last_safe) {
+			if (time_after(jiffies,
+				       occ->last_safe + OCC_SAFE_TIMEOUT))
+				occ->error = -EHOSTDOWN;
+		} else {
+			occ->last_safe = jiffies;
+		}
+	} else {
+		occ->last_safe = 0;
+	}
+
+done:
+	occ_sysfs_poll_done(occ);
+	return rc;
 }
 
 static int occ_set_user_power_cap(struct occ *occ, u16 user_power_cap)
@@ -174,7 +209,7 @@ static int occ_set_user_power_cap(struct occ *occ, u16 user_power_cap)
 	return rc;
 }
 
-static int occ_update_response(struct occ *occ)
+int occ_update_response(struct occ *occ)
 {
 	int rc = mutex_lock_interruptible(&occ->lock);
 
@@ -1207,5 +1242,9 @@ int occ_setup(struct occ *occ, const char *name)
 		return rc;
 	}
 
-	return 0;
+	rc = occ_setup_sysfs(occ);
+	if (rc)
+		dev_err(occ->bus_dev, "failed to setup sysfs: %d\n", rc);
+
+	return rc;
 }
diff --git a/drivers/hwmon/occ/common.h b/drivers/hwmon/occ/common.h
index 2c1c06e..7bacbb6 100644
--- a/drivers/hwmon/occ/common.h
+++ b/drivers/hwmon/occ/common.h
@@ -112,8 +112,25 @@ struct occ {
 	struct occ_attribute *attrs;
 	struct attribute_group group;
 	const struct attribute_group *groups[2];
+
+	int 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;
 };
 
 int occ_setup(struct occ *occ, const char *name);
+int occ_setup_sysfs(struct occ *occ);
+void occ_shutdown(struct occ *occ);
+void occ_sysfs_poll_done(struct occ *occ);
+int occ_update_response(struct occ *occ);
 
 #endif /* OCC_COMMON_H */
diff --git a/drivers/hwmon/occ/p8_i2c.c b/drivers/hwmon/occ/p8_i2c.c
index 9a920db..63f3db8 100644
--- a/drivers/hwmon/occ/p8_i2c.c
+++ b/drivers/hwmon/occ/p8_i2c.c
@@ -232,6 +232,15 @@ static int p8_i2c_occ_probe(struct i2c_client *client,
 	return occ_setup(occ, "p8_occ");
 }
 
+static int p8_i2c_occ_remove(struct i2c_client *client)
+{
+	struct occ *occ = dev_get_drvdata(&client->dev);
+
+	occ_shutdown(occ);
+
+	return 0;
+}
+
 static const struct of_device_id p8_i2c_occ_of_match[] = {
 	{ .compatible = "ibm,p8-occ-hwmon" },
 	{}
@@ -245,6 +254,7 @@ static int p8_i2c_occ_probe(struct i2c_client *client,
 		.of_match_table = p8_i2c_occ_of_match,
 	},
 	.probe = p8_i2c_occ_probe,
+	.remove = p8_i2c_occ_remove,
 };
 
 module_i2c_driver(p8_i2c_occ_driver);
diff --git a/drivers/hwmon/occ/p9_sbe.c b/drivers/hwmon/occ/p9_sbe.c
index fb32788..e379b05 100644
--- a/drivers/hwmon/occ/p9_sbe.c
+++ b/drivers/hwmon/occ/p9_sbe.c
@@ -95,6 +95,7 @@ static int p9_sbe_occ_remove(struct platform_device *pdev)
 	struct p9_sbe_occ *ctx = to_p9_sbe_occ(occ);
 
 	ctx->sbe = NULL;
+	occ_shutdown(occ);
 
 	return 0;
 }
diff --git a/drivers/hwmon/occ/sysfs.c b/drivers/hwmon/occ/sysfs.c
new file mode 100644
index 0000000..743b26ec
--- /dev/null
+++ b/drivers/hwmon/occ/sysfs.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * OCC hwmon driver sysfs interface
+ *
+ * Copyright (C) IBM Corporation 2018
+ *
+ * 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.
+ */
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/kernel.h>
+#include <linux/sysfs.h>
+
+#include "common.h"
+
+/* OCC status register */
+#define OCC_STAT_MASTER			BIT(7)
+#define OCC_STAT_ACTIVE			BIT(0)
+
+/* OCC extended status register */
+#define OCC_EXT_STAT_DVFS_OT		BIT(7)
+#define OCC_EXT_STAT_DVFS_POWER		BIT(6)
+#define OCC_EXT_STAT_MEM_THROTTLE	BIT(5)
+#define OCC_EXT_STAT_QUICK_DROP		BIT(4)
+
+static ssize_t occ_sysfs_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	int rc;
+	int val = 0;
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_poll_response_header *header;
+	struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
+
+	rc = occ_update_response(occ);
+	if (rc)
+		return rc;
+
+	header = (struct occ_poll_response_header *)occ->resp.data;
+
+	switch (sattr->index) {
+	case 0:
+		val = !!(header->status & OCC_STAT_MASTER);
+		break;
+	case 1:
+		val = !!(header->status & OCC_STAT_ACTIVE);
+		break;
+	case 2:
+		val = !!(header->status & OCC_EXT_STAT_DVFS_OT);
+		break;
+	case 3:
+		val = !!(header->status & OCC_EXT_STAT_DVFS_POWER);
+		break;
+	case 4:
+		val = !!(header->status & OCC_EXT_STAT_MEM_THROTTLE);
+		break;
+	case 5:
+		val = !!(header->status & OCC_EXT_STAT_QUICK_DROP);
+		break;
+	case 6:
+		val = header->occ_state;
+		break;
+	case 7:
+		if (header->status & OCC_STAT_MASTER)
+			val = hweight8(header->occs_present);
+		else
+			val = 1;
+		break;
+	case 8:
+		val = occ->error;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return snprintf(buf, PAGE_SIZE - 1, "%d\n", val);
+}
+
+static SENSOR_DEVICE_ATTR(occ_master, 0444, occ_sysfs_show, NULL, 0);
+static SENSOR_DEVICE_ATTR(occ_active, 0444, occ_sysfs_show, NULL, 1);
+static SENSOR_DEVICE_ATTR(occ_dvfs_overtemp, 0444, occ_sysfs_show, NULL, 2);
+static SENSOR_DEVICE_ATTR(occ_dvfs_power, 0444, occ_sysfs_show, NULL, 3);
+static SENSOR_DEVICE_ATTR(occ_mem_throttle, 0444, occ_sysfs_show, NULL, 4);
+static SENSOR_DEVICE_ATTR(occ_quick_pwr_drop, 0444, occ_sysfs_show, NULL, 5);
+static SENSOR_DEVICE_ATTR(occ_state, 0444, occ_sysfs_show, NULL, 6);
+static SENSOR_DEVICE_ATTR(occs_present, 0444, occ_sysfs_show, NULL, 7);
+static SENSOR_DEVICE_ATTR(occ_error, 0444, occ_sysfs_show, NULL, 8);
+
+static struct attribute *occ_attributes[] = {
+	&sensor_dev_attr_occ_master.dev_attr.attr,
+	&sensor_dev_attr_occ_active.dev_attr.attr,
+	&sensor_dev_attr_occ_dvfs_overtemp.dev_attr.attr,
+	&sensor_dev_attr_occ_dvfs_power.dev_attr.attr,
+	&sensor_dev_attr_occ_mem_throttle.dev_attr.attr,
+	&sensor_dev_attr_occ_quick_pwr_drop.dev_attr.attr,
+	&sensor_dev_attr_occ_state.dev_attr.attr,
+	&sensor_dev_attr_occs_present.dev_attr.attr,
+	&sensor_dev_attr_occ_error.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group occ_sysfs = {
+	.attrs = occ_attributes,
+};
+
+void occ_sysfs_poll_done(struct occ *occ)
+{
+	const char *name;
+	struct occ_poll_response_header *header =
+		(struct occ_poll_response_header *)occ->resp.data;
+
+	/*
+	 * On the first poll response, we haven't yet created the sysfs
+	 * attributes, so don't make any notify calls.
+	 */
+	if (!occ->hwmon)
+		goto done;
+
+	if ((header->status & OCC_STAT_MASTER) !=
+	    (occ->prev_stat & OCC_STAT_MASTER)) {
+		name = sensor_dev_attr_occ_master.dev_attr.attr.name;
+		sysfs_notify(&occ->bus_dev->kobj, NULL, name);
+	}
+
+	if ((header->status & OCC_STAT_ACTIVE) !=
+	    (occ->prev_stat & OCC_STAT_ACTIVE)) {
+		name = sensor_dev_attr_occ_active.dev_attr.attr.name;
+		sysfs_notify(&occ->bus_dev->kobj, NULL, name);
+	}
+
+	if ((header->ext_status & OCC_EXT_STAT_DVFS_OT) !=
+	    (occ->prev_ext_stat & OCC_EXT_STAT_DVFS_OT)) {
+		name = sensor_dev_attr_occ_dvfs_overtemp.dev_attr.attr.name;
+		sysfs_notify(&occ->bus_dev->kobj, NULL, name);
+	}
+
+	if ((header->ext_status & OCC_EXT_STAT_DVFS_POWER) !=
+	    (occ->prev_ext_stat & OCC_EXT_STAT_DVFS_POWER)) {
+		name = sensor_dev_attr_occ_dvfs_power.dev_attr.attr.name;
+		sysfs_notify(&occ->bus_dev->kobj, NULL, name);
+	}
+
+	if ((header->ext_status & OCC_EXT_STAT_MEM_THROTTLE) !=
+	    (occ->prev_ext_stat & OCC_EXT_STAT_MEM_THROTTLE)) {
+		name = sensor_dev_attr_occ_mem_throttle.dev_attr.attr.name;
+		sysfs_notify(&occ->bus_dev->kobj, NULL, name);
+	}
+
+	if ((header->ext_status & OCC_EXT_STAT_QUICK_DROP) !=
+	    (occ->prev_ext_stat & OCC_EXT_STAT_QUICK_DROP)) {
+		name = sensor_dev_attr_occ_quick_pwr_drop.dev_attr.attr.name;
+		sysfs_notify(&occ->bus_dev->kobj, NULL, name);
+	}
+
+	if ((header->status & OCC_STAT_MASTER) &&
+	    header->occs_present != occ->prev_occs_present) {
+		name = sensor_dev_attr_occs_present.dev_attr.attr.name;
+		sysfs_notify(&occ->bus_dev->kobj, NULL, name);
+	}
+
+	if (occ->error && occ->error != occ->prev_error) {
+		name = sensor_dev_attr_occ_error.dev_attr.attr.name;
+		sysfs_notify(&occ->bus_dev->kobj, NULL, name);
+	}
+
+	/* no notifications for OCC state; doesn't indicate error condition */
+
+done:
+	occ->prev_error = occ->error;
+	occ->prev_stat = header->status;
+	occ->prev_ext_stat = header->ext_status;
+	occ->prev_occs_present = header->occs_present;
+}
+
+int occ_setup_sysfs(struct occ *occ)
+{
+	return sysfs_create_group(&occ->bus_dev->kobj, &occ_sysfs);
+}
+
+void occ_shutdown(struct occ *occ)
+{
+	sysfs_remove_group(&occ->bus_dev->kobj, &occ_sysfs);
+}
-- 
1.8.3.1

Re: [PATCH v4 1/9] fsi: Add On-Chip Controller (OCC) driver

[Guenter Roeck]

On Wed, Jul 11, 2018 at 04:01:30PM -0500, Eddie James wrote:
> The OCC is a device embedded on a POWER processor that collects and
> aggregates sensor data from the processor and system. The OCC can
> provide the raw sensor data as well as perform thermal and power
> management on the system.
> 
> This driver provides an atomic communications channel between a service
> processor (e.g. a BMC) and the OCC. The driver is dependent on the FSI
> SBEFIFO driver to get hardware access through the SBE to the OCC SRAM.
> Commands are issued to the SBE to send or fetch data to the SRAM.
> 
> Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
> Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Signed-off-by: Joel Stanley <joel@jms.id.au>
> ---
>  drivers/fsi/Kconfig     |  10 +
>  drivers/fsi/Makefile    |   1 +
>  drivers/fsi/fsi-occ.c   | 609 ++++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/fsi-occ.h |  34 +++
>  4 files changed, 654 insertions(+)
>  create mode 100644 drivers/fsi/fsi-occ.c
>  create mode 100644 include/linux/fsi-occ.h
> 
> diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig
> index 24f84a9..322cec3 100644
> --- a/drivers/fsi/Kconfig
> +++ b/drivers/fsi/Kconfig
> @@ -39,4 +39,14 @@ config FSI_SBEFIFO
>  	a pipe-like FSI device for communicating with the self boot engine
>  	(SBE) on POWER processors.
>  
> +config FSI_OCC
> +	tristate "OCC SBEFIFO client device driver"
> +	depends on FSI_SBEFIFO
> +	---help---
> +	This option enables an SBEFIFO based On-Chip Controller (OCC) device
> +	driver. The OCC is a device embedded on a POWER processor that collects
> +	and aggregates sensor data from the processor and system. The OCC can
> +	provide the raw sensor data as well as perform thermal and power
> +	management on the system.
> +
>  endif
> diff --git a/drivers/fsi/Makefile b/drivers/fsi/Makefile
> index 851182e..75fdc6d 100644
> --- a/drivers/fsi/Makefile
> +++ b/drivers/fsi/Makefile
> @@ -4,3 +4,4 @@ obj-$(CONFIG_FSI_MASTER_HUB) += fsi-master-hub.o
>  obj-$(CONFIG_FSI_MASTER_GPIO) += fsi-master-gpio.o
>  obj-$(CONFIG_FSI_SCOM) += fsi-scom.o
>  obj-$(CONFIG_FSI_SBEFIFO) += fsi-sbefifo.o
> +obj-$(CONFIG_FSI_OCC) += fsi-occ.o
> diff --git a/drivers/fsi/fsi-occ.c b/drivers/fsi/fsi-occ.c
> new file mode 100644
> index 0000000..bba67a6
> --- /dev/null
> +++ b/drivers/fsi/fsi-occ.c
> @@ -0,0 +1,609 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * On-Chip Controller Driver
> + *
> + * Copyright (C) IBM Corporation 2018
> + *
> + * 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.

I thought the whole idea of using SPDX license identifiers was to get rid
of this boilerplate.

> + */
> +
> +#include <asm/unaligned.h>

asm includes should be after generic includes.

> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/errno.h>
> +#include <linux/fs.h>
> +#include <linux/fsi-sbefifo.h>
> +#include <linux/gfp.h>
> +#include <linux/idr.h>
> +#include <linux/kernel.h>
> +#include <linux/list.h>
> +#include <linux/miscdevice.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/fsi-occ.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/sched.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +
> +#define OCC_SRAM_BYTES		4096
> +#define OCC_CMD_DATA_BYTES	4090
> +#define OCC_RESP_DATA_BYTES	4089
> +
> +#define OCC_SRAM_CMD_ADDR	0xFFFBE000
> +#define OCC_SRAM_RSP_ADDR	0xFFFBF000
> +
> +/*
> + * Assume we don't have much FFDC, if we do we'll overflow and
> + * fail the command. This needs to be big enough for simple
> + * commands as well.
> + */
> +#define OCC_SBE_STATUS_WORDS	32
> +
> +#define OCC_TIMEOUT_MS		1000
> +#define OCC_CMD_IN_PRG_WAIT_MS	50
> +
> +struct occ {
> +	struct device *dev;
> +	struct device *sbefifo;
> +	char name[32];
> +	int idx;
> +	struct miscdevice mdev;
> +	struct mutex occ_lock;
> +};
> +
> +#define to_occ(x)	container_of((x), struct occ, mdev)
> +
> +struct occ_response {
> +	u8 seq_no;
> +	u8 cmd_type;
> +	u8 return_status;
> +	__be16 data_length;
> +	u8 data[OCC_RESP_DATA_BYTES + 2];	/* two bytes checksum */
> +} __packed;
> +
> +struct occ_client {
> +	struct occ *occ;
> +	struct mutex lock;
> +	size_t data_size;
> +	size_t read_offset;
> +	u8 *buffer;
> +};
> +
> +#define to_client(x)	container_of((x), struct occ_client, xfr)
> +
> +static DEFINE_IDA(occ_ida);
> +
> +static int occ_open(struct inode *inode, struct file *file)
> +{
> +	struct occ_client *client = kzalloc(sizeof(*client), GFP_KERNEL);
> +	struct miscdevice *mdev = file->private_data;
> +	struct occ *occ = to_occ(mdev);
> +
> +	if (!client)
> +		return -ENOMEM;
> +
> +	client->buffer = (u8 *)__get_free_page(GFP_KERNEL);
> +	if (!client->buffer) {
> +		kfree(client);
> +		return -ENOMEM;
> +	}
> +
> +	client->occ = occ;
> +	mutex_init(&client->lock);
> +	file->private_data = client;
> +
> +	/* We allocate a 1-page buffer, make sure it all fits */
> +	BUILD_BUG_ON((OCC_CMD_DATA_BYTES + 3) > PAGE_SIZE);
> +	BUILD_BUG_ON((OCC_RESP_DATA_BYTES + 7) > PAGE_SIZE);
> +
> +	return 0;
> +}
> +
> +static ssize_t occ_read(struct file *file, char __user *buf, size_t len,
> +			loff_t *offset)
> +{
> +	struct occ_client *client = file->private_data;
> +	ssize_t rc = 0;
> +
> +	if (!client)
> +		return -ENODEV;
> +
> +	if (len > OCC_SRAM_BYTES)
> +		return -EINVAL;
> +
> +	mutex_lock(&client->lock);
> +
> +	/* This should not be possible ... */
> +	if (WARN_ON_ONCE(client->read_offset > client->data_size)) {
> +		rc = -EIO;
> +		goto done;
> +	}
> +
> +	/* Grab how much data we have to read */
> +	rc = min(len, client->data_size - client->read_offset);
> +	if (copy_to_user(buf, client->buffer + client->read_offset, rc))
> +		rc = -EFAULT;
> +	else
> +		client->read_offset += rc;
> +
> + done:
> +	mutex_unlock(&client->lock);
> +
> +	return rc;
> +}
> +
> +static ssize_t occ_write(struct file *file, const char __user *buf,
> +			 size_t len, loff_t *offset)
> +{
> +	struct occ_client *client = file->private_data;
> +	size_t rlen, data_length;
> +	u16 checksum = 0;
> +	ssize_t rc, i;
> +	u8 *cmd;
> +
> +	if (!client)
> +		return -ENODEV;
> +
> +	if (len > (OCC_CMD_DATA_BYTES + 3) || len < 3)
> +		return -EINVAL;
> +
> +	mutex_lock(&client->lock);
> +
> +	/* Construct the command */
> +	cmd = client->buffer;
> +
> +	/* Sequence number (we could increment and compare with response) */
> +	cmd[0] = 1;
> +
> +	/*
> +	 * Copy the user command (assume user data follows the occ command
> +	 * format)
> +	 * byte 0: command type
> +	 * bytes 1-2: data length (msb first)
> +	 * bytes 3-n: data
> +	 */
> +	if (copy_from_user(&cmd[1], buf, len)) {
> +		rc = -EFAULT;
> +		goto done;
> +	}
> +
> +	/* Extract data length */
> +	data_length = (cmd[2] << 8) + cmd[3];
> +	if (data_length > OCC_CMD_DATA_BYTES) {
> +		rc = -EINVAL;
> +		goto done;
> +	}
> +
> +	/* Calculate checksum */
> +	for (i = 0; i < data_length + 4; ++i)
> +		checksum += cmd[i];
> +
> +	cmd[data_length + 4] = checksum >> 8;
> +	cmd[data_length + 5] = checksum & 0xFF;
> +
> +	/* Submit command */
> +	rlen = PAGE_SIZE;
> +	rc = fsi_occ_submit(client->occ->dev, cmd, data_length + 6, cmd,
> +			    &rlen);
> +	if (rc)
> +		goto done;
> +
> +	/* Set read tracking data */
> +	client->data_size = rlen;
> +	client->read_offset = 0;
> +
> +	/* Done */
> +	rc = len;
> +
> + done:
> +	mutex_unlock(&client->lock);
> +
> +	return rc;
> +}
> +
> +static int occ_release(struct inode *inode, struct file *file)
> +{
> +	struct occ_client *client = file->private_data;
> +
> +	free_page((unsigned long)client->buffer);
> +	kfree(client);
> +
> +	return 0;
> +}
> +
> +static const struct file_operations occ_fops = {
> +	.owner = THIS_MODULE,
> +	.open = occ_open,
> +	.read = occ_read,
> +	.write = occ_write,
> +	.release = occ_release,
> +};
> +
> +static int occ_verify_checksum(struct occ_response *resp, u16 data_length)
> +{
> +	/* Fetch the two bytes after the data for the checksum. */
> +	u16 checksum_resp = get_unaligned_be16(&resp->data[data_length]);
> +	u16 checksum;
> +	u16 i;
> +
> +	checksum = resp->seq_no;
> +	checksum += resp->cmd_type;
> +	checksum += resp->return_status;
> +	checksum += (data_length >> 8) + (data_length & 0xFF);
> +
> +	for (i = 0; i < data_length; ++i)
> +		checksum += resp->data[i];
> +
> +	if (checksum != checksum_resp)
> +		return -EBADMSG;
> +
> +	return 0;
> +}
> +
> +static int occ_getsram(struct occ *occ, u32 address, void *data, ssize_t len)
> +{
> +	u32 data_len = ((len + 7) / 8) * 8;	/* must be multiples of 8 B */
> +	size_t resp_len, resp_data_len;
> +	__be32 *resp, cmd[5];
> +	int rc;
> +
> +	/*
> +	 * Magic sequence to do SBE getsram command. SBE will fetch data from
> +	 * specified SRAM address.
> +	 */
> +	cmd[0] = cpu_to_be32(0x5);
> +	cmd[1] = cpu_to_be32(SBEFIFO_CMD_GET_OCC_SRAM);
> +	cmd[2] = cpu_to_be32(1);
> +	cmd[3] = cpu_to_be32(address);
> +	cmd[4] = cpu_to_be32(data_len);
> +
> +	resp_len = (data_len >> 2) + OCC_SBE_STATUS_WORDS;
> +	resp = kzalloc(resp_len << 2, GFP_KERNEL);
> +	if (!resp)
> +		return -ENOMEM;
> +
> +	rc = sbefifo_submit(occ->sbefifo, cmd, 5, resp, &resp_len);
> +	if (rc)
> +		goto free;
> +
> +	rc = sbefifo_parse_status(occ->sbefifo, SBEFIFO_CMD_GET_OCC_SRAM,
> +				  resp, resp_len, &resp_len);
> +	if (rc)
> +		goto free;
> +
> +	resp_data_len = be32_to_cpu(resp[resp_len - 1]);
> +	if (resp_data_len != data_len) {
> +		dev_err(occ->dev, "SRAM read expected %d bytes got %zd\n",
> +			data_len, resp_data_len);
> +		rc = -EBADMSG;
> +	} else {
> +		memcpy(data, resp, len);
> +	}
> +
> +free:
> +	/* Convert positive SBEI status */
> +	if (rc > 0) {
> +		dev_err(occ->dev, "SRAM read returned failure status: %08x\n",
> +			rc);
> +		rc = -EBADMSG;
> +	}
> +
> +	kfree(resp);
> +	return rc;
> +}
> +
> +static int occ_putsram(struct occ *occ, u32 address, const void *data,
> +		       ssize_t len)
> +{
> +	size_t cmd_len, buf_len, resp_len, resp_data_len;
> +	u32 data_len = ((len + 7) / 8) * 8;	/* must be multiples of 8 B */
> +	__be32 *buf;
> +	int rc;
> +
> +	/*
> +	 * We use the same buffer for command and response, make
> +	 * sure it's big enough
> +	 */
> +	resp_len = OCC_SBE_STATUS_WORDS;
> +	cmd_len = (data_len >> 2) + 5;
> +	buf_len = max(cmd_len, resp_len);
> +	buf = kzalloc(buf_len << 2, GFP_KERNEL);
> +	if (!buf)
> +		return -ENOMEM;
> +
> +	/*
> +	 * Magic sequence to do SBE putsram command. SBE will transfer
> +	 * data to specified SRAM address.
> +	 */
> +	buf[0] = cpu_to_be32(cmd_len);
> +	buf[1] = cpu_to_be32(SBEFIFO_CMD_PUT_OCC_SRAM);
> +	buf[2] = cpu_to_be32(1);
> +	buf[3] = cpu_to_be32(address);
> +	buf[4] = cpu_to_be32(data_len);
> +
> +	memcpy(&buf[5], data, len);
> +
> +	rc = sbefifo_submit(occ->sbefifo, buf, cmd_len, buf, &resp_len);
> +	if (rc)
> +		goto free;
> +
> +	rc = sbefifo_parse_status(occ->sbefifo, SBEFIFO_CMD_PUT_OCC_SRAM,
> +				  buf, resp_len, &resp_len);
> +	if (rc)
> +		goto free;
> +
> +	if (resp_len != 1) {
> +		dev_err(occ->dev, "SRAM write response length invalid: %zd\n",
> +			resp_len);
> +		rc = -EBADMSG;
> +	} else {
> +		resp_data_len = be32_to_cpu(buf[0]);
> +		if (resp_data_len != data_len) {
> +			dev_err(occ->dev,
> +				"SRAM write expected %d bytes got %zd\n",
> +				data_len, resp_data_len);
> +			rc = -EBADMSG;
> +		}
> +	}
> +
> +free:
> +	/* Convert positive SBEI status */
> +	if (rc > 0) {
> +		dev_err(occ->dev, "SRAM write returned failure status: %08x\n",
> +			rc);
> +		rc = -EBADMSG;
> +	}
> +
> +	kfree(buf);
> +	return rc;
> +}
> +
> +static int occ_trigger_attn(struct occ *occ)
> +{
> +	__be32 buf[OCC_SBE_STATUS_WORDS];
> +	size_t resp_len, resp_data_len;
> +	int rc;
> +
> +	BUILD_BUG_ON(OCC_SBE_STATUS_WORDS < 7);
> +	resp_len = OCC_SBE_STATUS_WORDS;
> +
> +	buf[0] = cpu_to_be32(0x5 + 0x2);        /* Chip-op length in words */
> +	buf[1] = cpu_to_be32(SBEFIFO_CMD_PUT_OCC_SRAM);
> +	buf[2] = cpu_to_be32(0x3);              /* Mode: Circular */
> +	buf[3] = cpu_to_be32(0x0);              /* Address: ignore in mode 3 */
> +	buf[4] = cpu_to_be32(0x8);              /* Data length in bytes */
> +	buf[5] = cpu_to_be32(0x20010000);       /* Trigger OCC attention */
> +	buf[6] = 0;
> +
> +	rc = sbefifo_submit(occ->sbefifo, buf, 7, buf, &resp_len);
> +	if (rc)
> +		goto error;
> +
> +	rc = sbefifo_parse_status(occ->sbefifo, SBEFIFO_CMD_PUT_OCC_SRAM,
> +				  buf, resp_len, &resp_len);
> +	if (rc)
> +		goto error;
> +
> +	if (resp_len != 1) {
> +		dev_err(occ->dev, "SRAM attn response length invalid: %zd\n",
> +			resp_len);
> +		rc = -EBADMSG;
> +	} else {
> +		resp_data_len = be32_to_cpu(buf[0]);
> +		if (resp_data_len != 8) {
> +			dev_err(occ->dev,
> +				"SRAM attn expected 8 bytes got %zd\n",
> +				resp_data_len);
> +			rc = -EBADMSG;
> +		}
> +	}
> +
> + error:
> +	/* Convert positive SBEI status */
> +	if (rc > 0) {
> +		dev_err(occ->dev, "SRAM attn returned failure status: %08x\n",
> +			rc);
> +		rc = -EBADMSG;
> +	}
> +
> +	return rc;
> +}
> +
> +int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
> +		   void *response, size_t *resp_len)
> +{
> +	const unsigned long timeout = msecs_to_jiffies(OCC_TIMEOUT_MS);
> +	const unsigned long wait_time =
> +		msecs_to_jiffies(OCC_CMD_IN_PRG_WAIT_MS);
> +	struct occ *occ = dev_get_drvdata(dev);
> +	struct occ_response *resp = response;
> +	u16 resp_data_length;
> +	unsigned long start;
> +	int rc;
> +
> +	if (!occ)
> +		return -ENODEV;
> +
> +	if (*resp_len < 7) {
> +		dev_dbg(dev, "Bad resplen %zd\n", *resp_len);
> +		return -EINVAL;
> +	}
> +
> +	mutex_lock(&occ->occ_lock);
> +
> +	rc = occ_putsram(occ, OCC_SRAM_CMD_ADDR, request, req_len);
> +	if (rc)
> +		goto done;
> +
> +	rc = occ_trigger_attn(occ);
> +	if (rc)
> +		goto done;
> +
> +	/* Read occ response header */
> +	start = jiffies;
> +	do {
> +		rc = occ_getsram(occ, OCC_SRAM_RSP_ADDR, resp, 8);
> +		if (rc)
> +			goto done;
> +
> +		if (resp->return_status == OCC_RESP_CMD_IN_PRG) {
> +			rc = -ETIMEDOUT;
> +
> +			if (time_after(jiffies, start + timeout))
> +				break;
> +
> +			set_current_state(TASK_UNINTERRUPTIBLE);
> +			schedule_timeout(wait_time);
> +		}
> +	} while (rc);
> +
> +	/* Extract size of response data */
> +	resp_data_length = get_unaligned_be16(&resp->data_length);
> +
> +	/* Message size is data length + 5 bytes header + 2 bytes checksum */
> +	if ((resp_data_length + 7) > *resp_len) {
> +		rc = -EMSGSIZE;
> +		goto done;
> +	}
> +
> +	dev_dbg(dev, "resp_status=%02x resp_data_len=%d\n",
> +		resp->return_status, resp_data_length);
> +
> +	/* Grab the rest */
> +	if (resp_data_length > 1) {
> +		/* already got 3 bytes resp, also need 2 bytes checksum */
> +		rc = occ_getsram(occ, OCC_SRAM_RSP_ADDR + 8,
> +				 &resp->data[3], resp_data_length - 1);
> +		if (rc)
> +			goto done;
> +	}
> +
> +	*resp_len = resp_data_length + 7;
> +	rc = occ_verify_checksum(resp, resp_data_length);
> +
> + done:
> +	mutex_unlock(&occ->occ_lock);
> +
> +	return rc;
> +}
> +EXPORT_SYMBOL_GPL(fsi_occ_submit);
> +
> +static int occ_unregister_child(struct device *dev, void *data)
> +{
> +	struct platform_device *hwmon_dev = to_platform_device(dev);
> +
> +	platform_device_unregister(hwmon_dev);
> +
> +	return 0;
> +}
> +
> +static int occ_probe(struct platform_device *pdev)
> +{
> +	int rc;
> +	u32 reg;
> +	struct occ *occ;
> +	struct platform_device *hwmon_dev;
> +	struct device *dev = &pdev->dev;
> +	struct platform_device_info hwmon_dev_info = {
> +		.parent = dev,
> +		.name = "occ-hwmon",
> +	};
> +
> +	occ = devm_kzalloc(dev, sizeof(*occ), GFP_KERNEL);
> +	if (!occ)
> +		return -ENOMEM;
> +
> +	occ->dev = dev;
> +	occ->sbefifo = dev->parent;
> +	mutex_init(&occ->occ_lock);
> +
> +	if (dev->of_node) {
> +		rc = of_property_read_u32(dev->of_node, "reg", &reg);
> +		if (!rc) {
> +			/* make sure we don't have a duplicate from dts */
> +			occ->idx = ida_simple_get(&occ_ida, reg, reg + 1,
> +						  GFP_KERNEL);
> +			if (occ->idx < 0)
> +				occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX,
> +							  GFP_KERNEL);
> +		} else {
> +			occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX,
> +						  GFP_KERNEL);
> +		}
> +	} else {
> +		occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX, GFP_KERNEL);
> +	}
> +
> +	platform_set_drvdata(pdev, occ);
> +
> +	snprintf(occ->name, sizeof(occ->name), "occ%d", occ->idx);
> +	occ->mdev.fops = &occ_fops;
> +	occ->mdev.minor = MISC_DYNAMIC_MINOR;
> +	occ->mdev.name = occ->name;
> +	occ->mdev.parent = dev;
> +
> +	rc = misc_register(&occ->mdev);
> +	if (rc) {
> +		dev_err(dev, "failed to register miscdevice: %d\n", rc);
> +		ida_simple_remove(&occ_ida, occ->idx);
> +		return rc;
> +	}
> +
> +	hwmon_dev_info.id = occ->idx;
> +	hwmon_dev = platform_device_register_full(&hwmon_dev_info);
> +	if (!hwmon_dev)
> +		dev_warn(dev, "failed to create hwmon device\n");
> +

Not my call to make, but since you are using devicetree I would have
thought it would be possible to use something like of_platform_populate()
to register child drivers.

> +	return 0;
> +}
> +
> +static int occ_remove(struct platform_device *pdev)
> +{
> +	struct occ *occ = platform_get_drvdata(pdev);
> +
> +	misc_deregister(&occ->mdev);
> +
> +	device_for_each_child(&pdev->dev, NULL, occ_unregister_child);
> +
> +	ida_simple_remove(&occ_ida, occ->idx);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id occ_match[] = {
> +	{ .compatible = "ibm,p9-occ" },
> +	{ },
> +};
> +
> +static struct platform_driver occ_driver = {
> +	.driver = {
> +		.name = "occ",
> +		.of_match_table	= occ_match,
> +	},
> +	.probe	= occ_probe,
> +	.remove = occ_remove,
> +};
> +
> +static int occ_init(void)
> +{
> +	return platform_driver_register(&occ_driver);
> +}
> +
> +static void occ_exit(void)
> +{
> +	platform_driver_unregister(&occ_driver);
> +
> +	ida_destroy(&occ_ida);
> +}
> +
> +module_init(occ_init);
> +module_exit(occ_exit);
> +
> +MODULE_AUTHOR("Eddie James <eajames@linux.vnet.ibm.com>");
> +MODULE_DESCRIPTION("BMC P9 OCC driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/fsi-occ.h b/include/linux/fsi-occ.h
> new file mode 100644
> index 0000000..e28cf9a
> --- /dev/null
> +++ b/include/linux/fsi-occ.h
> @@ -0,0 +1,34 @@
> +/*
> + * On-Chip Controller Driver definitions and prototypes
> + *
> + * Copyright (C) IBM Corporation 2018
> + *
> + * 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.
> + */
> +
> +#ifndef LINUX_FSI_OCC_H
> +#define LINUX_FSI_OCC_H
> +
> +struct device;
> +
> +#define OCC_RESP_CMD_IN_PRG		0xFF
> +#define OCC_RESP_SUCCESS		0
> +#define OCC_RESP_CMD_INVAL		0x11
> +#define OCC_RESP_CMD_LEN_INVAL		0x12
> +#define OCC_RESP_DATA_INVAL		0x13
> +#define OCC_RESP_CHKSUM_ERR		0x14
> +#define OCC_RESP_INT_ERR		0x15
> +#define OCC_RESP_BAD_STATE		0x16
> +#define OCC_RESP_CRIT_EXCEPT		0xE0
> +#define OCC_RESP_CRIT_INIT		0xE1
> +#define OCC_RESP_CRIT_WATCHDOG		0xE2
> +#define OCC_RESP_CRIT_OCB		0xE3
> +#define OCC_RESP_CRIT_HW		0xE4
> +
> +int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
> +		   void *response, size_t *resp_len);
> +
> +#endif /* LINUX_FSI_OCC_H */

Re: [PATCH v4 2/9] Documentation: hwmon: Add OCC documentation

[Guenter Roeck]

On Wed, Jul 11, 2018 at 04:01:31PM -0500, Eddie James wrote:
> Document the hwmon interface for the OCC.
> 
> Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
> ---
>  Documentation/hwmon/occ | 73 +++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 73 insertions(+)
>  create mode 100644 Documentation/hwmon/occ
> 
> diff --git a/Documentation/hwmon/occ b/Documentation/hwmon/occ
> new file mode 100644
> index 0000000..465fa1a
> --- /dev/null
> +++ b/Documentation/hwmon/occ
> @@ -0,0 +1,73 @@
> +Kernel driver occ-hwmon
> +=======================
> +
> +Supported chips:
> +  * POWER8
> +  * POWER9
> +
> +Author: Eddie James <eajames@linux.vnet.ibm.com>
> +
> +Description
> +-----------
> +
> +This driver supports hardware monitoring for the On-Chip Controller (OCC)
> +embedded on POWER processors. The OCC is a device that collects and aggregates
> +sensor data from the processor and the system. The OCC can provide the raw
> +sensor data as well as perform thermal and power management on the system.
> +
> +The P8 version of this driver is a client driver of I2C. It may be probed
> +manually if an "ibm,p8-occ-hwmon" compatible device is found under the
> +appropriate I2C bus node in the device-tree.
> +
> +The P9 version of this driver is a client driver of the FSI-based OCC driver.
> +It will be probed automatically by the FSI-based OCC driver.
> +
> +Sysfs entries
> +-------------
> +
> +The following attributes are supported. All attributes are read-only unless
> +specified.
> +
> +temp[1-n]_label		OCC sensor id.
> +temp[1-n]_input		Measured temperature in millidegrees C.
> +[with temperature sensor version 2+]
> +    temp[1-n]_fru_type		Given FRU (Field Replaceable Unit) type.

What is this ? An integer ? A string ?

> +    temp[1-n]_fault		Temperature sensor fault.
> +
> +freq[1-n]_label		OCC sensor id.
> +freq[1-n]_input		Measured frequency.

What does that have to do with hardware monitoring, and what exactly does it
measure ? AC voltage frequency ? Frequency of rainstorms in the surrounding
area ?

> +
> +power[1-n]_label	OCC sensor id.
> +power[1-n]_input	Measured power in microwatts.
> +power[1-n]_update_tag	Number of 250us samples represented in accumulator.

update_tag to represent number of samples ? Odd choice for
an attribute name. Why not "_samples" ? Also, if each sample
represents a specific amount of time, why not report a time ?

> +power[1-n]_accumulator	Accumulation of 250us power readings.

There is no explanation of "accumulation". Is this the energy ?
If so, why not use energy attributes ? And what is the unit of
this measurement ?

> +[with power sensor version 2+]
> +    power[1-n]_function_id	Identifies what the power reading is for.

String ? Number ? Slot index ?  Bitmap ? And why isn't that reported
in the label ? After all, that is what the label is supposed to be
used for.

> +    power[1-n]_apss_channel	Indicates APSS channel.
> +

Does that provide any value to the user ?

> +[power version 0xa0 only]
> +power1_id			OCC sensor id.

This is inconsistent with the other attributes and even with itself.

> +power[1-n]_label		Sensor type, "system", "proc", "vdd", or "vdn".
> +power[1-n]_input		Most recent power reading in microwatts.

Overall I am left with no idea what
	_id
	_label
	_function_id
	_apps_channel
are and how they relate to each other, except that it all looks quite
inconsistent. You might want to consider merging all those attributes into
the label in some consistent way.

> +power[1-n]_update_tag		Number of samples in the accumulator.
> +power[1-n]_accumulator		Accumulation of power readings.

Same as above.

> +[with sensor type "system" and "proc" only]
> +    power[1-n]_update_time	Time in us that the power value is read.
> +
> +caps1_current		Current OCC power cap in watts.
> +caps1_reading		Current system output power in watts.
> +caps1_norm		Power cap without redundant power.
> +caps1_max		Maximum power cap.

Why do those have to be non-standard attributes ? Please explain why you can not
use power[1-n]_cap attributes.

> +[caps version 1 and 2 only]
> +    caps1_min		Minimum power cap.
> +[caps version 3+]
> +    caps1_min_hard		Hard minimum cap that can be set and held.
> +    caps1_min_soft		Soft minimum cap below hard, not guaranteed.
> +caps1_user		The powercap specified by the user. Will be 0 if no
> +			user powercap exists. This attribute is read-write.
> +[caps version 1+]
> +    caps1_user_source	Indicates how the user power limit was set.
> +
> +extn[1-n]_label		ASCII id or sensor id.
> +extn[1-n]_flags		Indicates type of label attribute.
> +extn[1-n]_input		Data.

Great non-explanation.

Not reviewing the series further. I am sure I asked that each non-standard
attribute is explained. There is neither an explanation why the attributes
are needed nor, in many cases, why non-standard attributes were chosen
instead of standard ones. On top of that, the non-standard attributes are
not even documented properly, leaving the reader wondering not only why
they are needed, but what they are used for in the first place.

Guenter

Re: [PATCH v4 2/9] Documentation: hwmon: Add OCC documentation

[Eddie James]

On 07/25/2018 11:36 AM, Guenter Roeck wrote:
> On Wed, Jul 11, 2018 at 04:01:31PM -0500, Eddie James wrote:
>> Document the hwmon interface for the OCC.
>>
>> Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
>> ---
>>   Documentation/hwmon/occ | 73 +++++++++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 73 insertions(+)
>>   create mode 100644 Documentation/hwmon/occ
>>
>> diff --git a/Documentation/hwmon/occ b/Documentation/hwmon/occ
>> new file mode 100644
>> index 0000000..465fa1a
>> --- /dev/null
>> +++ b/Documentation/hwmon/occ
>> @@ -0,0 +1,73 @@
>> +Kernel driver occ-hwmon
>> +=======================
>> +
>> +Supported chips:
>> +  * POWER8
>> +  * POWER9
>> +
>> +Author: Eddie James <eajames@linux.vnet.ibm.com>
>> +
>> +Description
>> +-----------
>> +
>> +This driver supports hardware monitoring for the On-Chip Controller (OCC)
>> +embedded on POWER processors. The OCC is a device that collects and aggregates
>> +sensor data from the processor and the system. The OCC can provide the raw
>> +sensor data as well as perform thermal and power management on the system.
>> +
>> +The P8 version of this driver is a client driver of I2C. It may be probed
>> +manually if an "ibm,p8-occ-hwmon" compatible device is found under the
>> +appropriate I2C bus node in the device-tree.
>> +
>> +The P9 version of this driver is a client driver of the FSI-based OCC driver.
>> +It will be probed automatically by the FSI-based OCC driver.
>> +
>> +Sysfs entries
>> +-------------
>> +
>> +The following attributes are supported. All attributes are read-only unless
>> +specified.
>> +
>> +temp[1-n]_label		OCC sensor id.
>> +temp[1-n]_input		Measured temperature in millidegrees C.
>> +[with temperature sensor version 2+]
>> +    temp[1-n]_fru_type		Given FRU (Field Replaceable Unit) type.
> What is this ? An integer ? A string ?
>
>> +    temp[1-n]_fault		Temperature sensor fault.
>> +
>> +freq[1-n]_label		OCC sensor id.
>> +freq[1-n]_input		Measured frequency.
> What does that have to do with hardware monitoring, and what exactly does it
> measure ? AC voltage frequency ? Frequency of rainstorms in the surrounding
> area ?
>
>> +
>> +power[1-n]_label	OCC sensor id.
>> +power[1-n]_input	Measured power in microwatts.
>> +power[1-n]_update_tag	Number of 250us samples represented in accumulator.
> update_tag to represent number of samples ? Odd choice for
> an attribute name. Why not "_samples" ? Also, if each sample
> represents a specific amount of time, why not report a time ?
>
>> +power[1-n]_accumulator	Accumulation of 250us power readings.
> There is no explanation of "accumulation". Is this the energy ?
> If so, why not use energy attributes ? And what is the unit of
> this measurement ?
>
>> +[with power sensor version 2+]
>> +    power[1-n]_function_id	Identifies what the power reading is for.
> String ? Number ? Slot index ?  Bitmap ? And why isn't that reported
> in the label ? After all, that is what the label is supposed to be
> used for.
>
>> +    power[1-n]_apss_channel	Indicates APSS channel.
>> +
> Does that provide any value to the user ?
>
>> +[power version 0xa0 only]
>> +power1_id			OCC sensor id.
> This is inconsistent with the other attributes and even with itself.
>
>> +power[1-n]_label		Sensor type, "system", "proc", "vdd", or "vdn".
>> +power[1-n]_input		Most recent power reading in microwatts.
> Overall I am left with no idea what
> 	_id
> 	_label
> 	_function_id
> 	_apps_channel
> are and how they relate to each other, except that it all looks quite
> inconsistent. You might want to consider merging all those attributes into
> the label in some consistent way.
>
>> +power[1-n]_update_tag		Number of samples in the accumulator.
>> +power[1-n]_accumulator		Accumulation of power readings.
> Same as above.
>
>> +[with sensor type "system" and "proc" only]
>> +    power[1-n]_update_time	Time in us that the power value is read.
>> +
>> +caps1_current		Current OCC power cap in watts.
>> +caps1_reading		Current system output power in watts.
>> +caps1_norm		Power cap without redundant power.
>> +caps1_max		Maximum power cap.
> Why do those have to be non-standard attributes ? Please explain why you can not
> use power[1-n]_cap attributes.
>
>> +[caps version 1 and 2 only]
>> +    caps1_min		Minimum power cap.
>> +[caps version 3+]
>> +    caps1_min_hard		Hard minimum cap that can be set and held.
>> +    caps1_min_soft		Soft minimum cap below hard, not guaranteed.
>> +caps1_user		The powercap specified by the user. Will be 0 if no
>> +			user powercap exists. This attribute is read-write.
>> +[caps version 1+]
>> +    caps1_user_source	Indicates how the user power limit was set.
>> +
>> +extn[1-n]_label		ASCII id or sensor id.
>> +extn[1-n]_flags		Indicates type of label attribute.
>> +extn[1-n]_input		Data.
> Great non-explanation.
>
> Not reviewing the series further. I am sure I asked that each non-standard
> attribute is explained. There is neither an explanation why the attributes
> are needed nor, in many cases, why non-standard attributes were chosen
> instead of standard ones. On top of that, the non-standard attributes are
> not even documented properly, leaving the reader wondering not only why
> they are needed, but what they are used for in the first place.

Hi,

Thanks for the feedback Guenter. I am about to put up a new patch set 
with fixes for many of the issues you indicated and better descriptions. 
Now all the attributes except two should conform to standard hwmon 
attributes. The exceptions are for the user power cap and user power cap 
source. These are needed in order to make decisions about power 
management while controlling the system. Please look at their 
documentation to see if they're acceptable.

Let me know what you think!
Thanks,
Eddie

>
> Guenter
>

Re: [PATCH v4 9/9] hwmon (occ): Add sysfs attributes for additional OCC data

[Thomas Gleixner]

Eddie,

On Wed, 11 Jul 2018, Eddie James wrote:

> --- /dev/null
> +++ b/drivers/hwmon/occ/sysfs.c
> @@ -0,0 +1,188 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * OCC hwmon driver sysfs interface
> + *
> + * Copyright (C) IBM Corporation 2018
> + *
> + * 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.
> + */

The above license information is inconsistent.

The SPDX license identifier says GPL v2 only, but the license notice says
GPL v2 or later. This is just wrong.

Please decide which one to use and please also remove the boiler plate
text. It is redundant.

See Documentation/process/license-rules.rst

Please fix ASAP.

Thanks,

	tglx

Re: [PATCH v4 9/9] hwmon (occ): Add sysfs attributes for additional OCC data

[Joel Stanley]

On Fri, 18 Jan 2019 at 11:44, Thomas Gleixner <tglx@linutronix.de> wrote:
>
> Eddie,
>
> On Wed, 11 Jul 2018, Eddie James wrote:
>
> > --- /dev/null
> > +++ b/drivers/hwmon/occ/sysfs.c
> > @@ -0,0 +1,188 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * OCC hwmon driver sysfs interface
> > + *
> > + * Copyright (C) IBM Corporation 2018
> > + *
> > + * 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.
> > + */
>
> The above license information is inconsistent.
>
> The SPDX license identifier says GPL v2 only, but the license notice says
> GPL v2 or later. This is just wrong.
>
> Please decide which one to use and please also remove the boiler plate
> text. It is redundant.
>
> See Documentation/process/license-rules.rst

Thanks Thomas.

Eddie, as IBM contributed code our preferred license is GPLv2+. Be
sure to include the copyright line in your header (I noticed some OCC
files are missing this, please audit all of your recent
contributions):

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

Cheers,

Joel