Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
 
#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>
#include <asm/unaligned.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;
<------>u8 seq_no;
<------>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);
 
<------>/* Extract the seq_no from the command (first byte) */
<------>seq_no = *(const u8 *)request;
<------>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 ||
<------><------>    resp->return_status == OCC_RESP_CRIT_INIT ||
<------><------>    resp->seq_no != seq_no) {
<------><------><------>rc = -ETIMEDOUT;
 
<------><------><------>if (time_after(jiffies, start + timeout)) {
<------><------><------><------>dev_err(occ->dev, "resp timeout status=%02x "
<------><------><------><------><------>"resp seq_no=%d our seq_no=%d\n",
<------><------><------><------><------>resp->return_status, resp->seq_no,
<------><------><------><------><------>seq_no);
<------><------><------><------>goto done;
<------><------><------>}
 
<------><------><------>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 (IS_ERR(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" },
<------>{ },
};
MODULE_DEVICE_TABLE(of, occ_match);
 
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.ibm.com>");
MODULE_DESCRIPTION("BMC P9 OCC driver");
MODULE_LICENSE("GPL");