// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2015 Zodiac Inflight Innovations
*
* Author: Martyn Welch <[email protected]>
*
* Based on twl4030_wdt.c by Timo Kokkonen <timo.t.kokkonen at nokia.com>:
*
* Copyright (C) Nokia Corporation
*/
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/ihex.h>
#include <linux/firmware.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#include <linux/unaligned.h>
#define ZIIRAVE_TIMEOUT_MIN 3
#define ZIIRAVE_TIMEOUT_MAX 255
#define ZIIRAVE_TIMEOUT_DEFAULT 30
#define ZIIRAVE_PING_VALUE 0x0
#define ZIIRAVE_STATE_INITIAL 0x0
#define ZIIRAVE_STATE_OFF 0x1
#define ZIIRAVE_STATE_ON 0x2
#define ZIIRAVE_FW_NAME "ziirave_wdt.fw"
static char *ziirave_reasons[] = {"power cycle", "hw watchdog", NULL, NULL,
"host request", NULL, "illegal configuration",
"illegal instruction", "illegal trap",
"unknown"};
#define ZIIRAVE_WDT_FIRM_VER_MAJOR 0x1
#define ZIIRAVE_WDT_BOOT_VER_MAJOR 0x3
#define ZIIRAVE_WDT_RESET_REASON 0x5
#define ZIIRAVE_WDT_STATE 0x6
#define ZIIRAVE_WDT_TIMEOUT 0x7
#define ZIIRAVE_WDT_TIME_LEFT 0x8
#define ZIIRAVE_WDT_PING 0x9
#define ZIIRAVE_WDT_RESET_DURATION 0xa
#define ZIIRAVE_FIRM_PKT_TOTAL_SIZE 20
#define ZIIRAVE_FIRM_PKT_DATA_SIZE 16
#define ZIIRAVE_FIRM_FLASH_MEMORY_START (2 * 0x1600)
#define ZIIRAVE_FIRM_FLASH_MEMORY_END (2 * 0x2bbf)
#define ZIIRAVE_FIRM_PAGE_SIZE 128
/* Received and ready for next Download packet. */
#define ZIIRAVE_FIRM_DOWNLOAD_ACK 1
/* Firmware commands */
#define ZIIRAVE_CMD_DOWNLOAD_START 0x10
#define ZIIRAVE_CMD_DOWNLOAD_END 0x11
#define ZIIRAVE_CMD_DOWNLOAD_SET_READ_ADDR 0x12
#define ZIIRAVE_CMD_DOWNLOAD_READ_BYTE 0x13
#define ZIIRAVE_CMD_RESET_PROCESSOR 0x0b
#define ZIIRAVE_CMD_JUMP_TO_BOOTLOADER 0x0c
#define ZIIRAVE_CMD_DOWNLOAD_PACKET 0x0e
#define ZIIRAVE_CMD_JUMP_TO_BOOTLOADER_MAGIC 1
#define ZIIRAVE_CMD_RESET_PROCESSOR_MAGIC 1
struct ziirave_wdt_rev {
unsigned char major;
unsigned char minor;
};
struct ziirave_wdt_data {
struct mutex sysfs_mutex;
struct watchdog_device wdd;
struct ziirave_wdt_rev bootloader_rev;
struct ziirave_wdt_rev firmware_rev;
int reset_reason;
};
static int wdt_timeout;
module_param(wdt_timeout, int, 0);
MODULE_PARM_DESC(wdt_timeout, "Watchdog timeout in seconds");
static int reset_duration;
module_param(reset_duration, int, 0);
MODULE_PARM_DESC(reset_duration,
"Watchdog reset pulse duration in milliseconds");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static int ziirave_wdt_revision(struct i2c_client *client,
struct ziirave_wdt_rev *rev, u8 command)
{
int ret;
ret = i2c_smbus_read_byte_data(client, command);
if (ret < 0)
return ret;
rev->major = ret;
ret = i2c_smbus_read_byte_data(client, command + 1);
if (ret < 0)
return ret;
rev->minor = ret;
return 0;
}
static int ziirave_wdt_set_state(struct watchdog_device *wdd, int state)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_STATE, state);
}
static int ziirave_wdt_start(struct watchdog_device *wdd)
{
return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_ON);
}
static int ziirave_wdt_stop(struct watchdog_device *wdd)
{
return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_OFF);
}
static int ziirave_wdt_ping(struct watchdog_device *wdd)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_PING,
ZIIRAVE_PING_VALUE);
}
static int ziirave_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
int ret;
ret = i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_TIMEOUT, timeout);
if (!ret)
wdd->timeout = timeout;
return ret;
}
static unsigned int ziirave_wdt_get_timeleft(struct watchdog_device *wdd)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
int ret;
ret = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIME_LEFT);
if (ret < 0)
ret = 0;
return ret;
}
static int ziirave_firm_read_ack(struct watchdog_device *wdd)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
int ret;
ret = i2c_smbus_read_byte(client);
if (ret < 0) {
dev_err(&client->dev, "Failed to read status byte\n");
return ret;
}
return ret == ZIIRAVE_FIRM_DOWNLOAD_ACK ? 0 : -EIO;
}
static int ziirave_firm_set_read_addr(struct watchdog_device *wdd, u32 addr)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
const u16 addr16 = (u16)addr / 2;
u8 address[2];
put_unaligned_le16(addr16, address);
return i2c_smbus_write_block_data(client,
ZIIRAVE_CMD_DOWNLOAD_SET_READ_ADDR,
sizeof(address), address);
}
static bool ziirave_firm_addr_readonly(u32 addr)
{
return addr < ZIIRAVE_FIRM_FLASH_MEMORY_START ||
addr > ZIIRAVE_FIRM_FLASH_MEMORY_END;
}
/*
* ziirave_firm_write_pkt() - Build and write a firmware packet
*
* A packet to send to the firmware is composed by following bytes:
* Length | Addr0 | Addr1 | Data0 .. Data15 | Checksum |
* Where,
* Length: A data byte containing the length of the data.
* Addr0: Low byte of the address.
* Addr1: High byte of the address.
* Data0 .. Data15: Array of 16 bytes of data.
* Checksum: Checksum byte to verify data integrity.
*/
static int __ziirave_firm_write_pkt(struct watchdog_device *wdd,
u32 addr, const u8 *data, u8 len)
{
const u16 addr16 = (u16)addr / 2;
struct i2c_client *client = to_i2c_client(wdd->parent);
u8 i, checksum = 0, packet[ZIIRAVE_FIRM_PKT_TOTAL_SIZE];
int ret;
/* Check max data size */
if (len > ZIIRAVE_FIRM_PKT_DATA_SIZE) {
dev_err(&client->dev, "Firmware packet too long (%d)\n",
len);
return -EMSGSIZE;
}
/*
* Ignore packets that are targeting program memory outisde of
* app partition, since they will be ignored by the
* bootloader. At the same time, we need to make sure we'll
* allow zero length packet that will be sent as the last step
* of firmware update
*/
if (len && ziirave_firm_addr_readonly(addr))
return 0;
/* Packet length */
packet[0] = len;
/* Packet address */
put_unaligned_le16(addr16, packet + 1);
memcpy(packet + 3, data, len);
memset(packet + 3 + len, 0, ZIIRAVE_FIRM_PKT_DATA_SIZE - len);
/* Packet checksum */
for (i = 0; i < len + 3; i++)
checksum += packet[i];
packet[ZIIRAVE_FIRM_PKT_TOTAL_SIZE - 1] = checksum;
ret = i2c_smbus_write_block_data(client, ZIIRAVE_CMD_DOWNLOAD_PACKET,
sizeof(packet), packet);
if (ret) {
dev_err(&client->dev,
"Failed to send DOWNLOAD_PACKET: %d\n", ret);
return ret;
}
ret = ziirave_firm_read_ack(wdd);
if (ret)
dev_err(&client->dev,
"Failed to write firmware packet at address 0x%04x: %d\n",
addr, ret);
return ret;
}
static int ziirave_firm_write_pkt(struct watchdog_device *wdd,
u32 addr, const u8 *data, u8 len)
{
const u8 max_write_len = ZIIRAVE_FIRM_PAGE_SIZE -
(addr - ALIGN_DOWN(addr, ZIIRAVE_FIRM_PAGE_SIZE));
int ret;
if (len > max_write_len) {
/*
* If data crossed page boundary we need to split this
* write in two
*/
ret = __ziirave_firm_write_pkt(wdd, addr, data, max_write_len);
if (ret)
return ret;
addr += max_write_len;
data += max_write_len;
len -= max_write_len;
}
return __ziirave_firm_write_pkt(wdd, addr, data, len);
}
static int ziirave_firm_verify(struct watchdog_device *wdd,
const struct firmware *fw)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
const struct ihex_binrec *rec;
int i, ret;
u8 data[ZIIRAVE_FIRM_PKT_DATA_SIZE];
for (rec = (void *)fw->data; rec; rec = ihex_next_binrec(rec)) {
const u16 len = be16_to_cpu(rec->len);
const u32 addr = be32_to_cpu(rec->addr);
if (ziirave_firm_addr_readonly(addr))
continue;
ret = ziirave_firm_set_read_addr(wdd, addr);
if (ret) {
dev_err(&client->dev,
"Failed to send SET_READ_ADDR command: %d\n",
ret);
return ret;
}
for (i = 0; i < len; i++) {
ret = i2c_smbus_read_byte_data(client,
ZIIRAVE_CMD_DOWNLOAD_READ_BYTE);
if (ret < 0) {
dev_err(&client->dev,
"Failed to READ DATA: %d\n", ret);
return ret;
}
data[i] = ret;
}
if (memcmp(data, rec->data, len)) {
dev_err(&client->dev,
"Firmware mismatch at address 0x%04x\n", addr);
return -EINVAL;
}
}
return 0;
}
static int ziirave_firm_upload(struct watchdog_device *wdd,
const struct firmware *fw)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
const struct ihex_binrec *rec;
int ret;
ret = i2c_smbus_write_byte_data(client,
ZIIRAVE_CMD_JUMP_TO_BOOTLOADER,
ZIIRAVE_CMD_JUMP_TO_BOOTLOADER_MAGIC);
if (ret) {
dev_err(&client->dev, "Failed to jump to bootloader\n");
return ret;
}
msleep(500);
ret = i2c_smbus_write_byte(client, ZIIRAVE_CMD_DOWNLOAD_START);
if (ret) {
dev_err(&client->dev, "Failed to start download\n");
return ret;
}
ret = ziirave_firm_read_ack(wdd);
if (ret) {
dev_err(&client->dev, "No ACK for start download\n");
return ret;
}
msleep(500);
for (rec = (void *)fw->data; rec; rec = ihex_next_binrec(rec)) {
ret = ziirave_firm_write_pkt(wdd, be32_to_cpu(rec->addr),
rec->data, be16_to_cpu(rec->len));
if (ret)
return ret;
}
/*
* Finish firmware download process by sending a zero length
* payload
*/
ret = ziirave_firm_write_pkt(wdd, 0, NULL, 0);
if (ret) {
dev_err(&client->dev, "Failed to send EMPTY packet: %d\n", ret);
return ret;
}
/* This sleep seems to be required */
msleep(20);
/* Start firmware verification */
ret = ziirave_firm_verify(wdd, fw);
if (ret) {
dev_err(&client->dev,
"Failed to verify firmware: %d\n", ret);
return ret;
}
/* End download operation */
ret = i2c_smbus_write_byte(client, ZIIRAVE_CMD_DOWNLOAD_END);
if (ret) {
dev_err(&client->dev,
"Failed to end firmware download: %d\n", ret);
return ret;
}
/* Reset the processor */
ret = i2c_smbus_write_byte_data(client,
ZIIRAVE_CMD_RESET_PROCESSOR,
ZIIRAVE_CMD_RESET_PROCESSOR_MAGIC);
if (ret) {
dev_err(&client->dev,
"Failed to reset the watchdog: %d\n", ret);
return ret;
}
msleep(500);
return 0;
}
static const struct watchdog_info ziirave_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
.identity = "RAVE Switch Watchdog",
};
static const struct watchdog_ops ziirave_wdt_ops = {
.owner = THIS_MODULE,
.start = ziirave_wdt_start,
.stop = ziirave_wdt_stop,
.ping = ziirave_wdt_ping,
.set_timeout = ziirave_wdt_set_timeout,
.get_timeleft = ziirave_wdt_get_timeleft,
};
static ssize_t ziirave_wdt_sysfs_show_firm(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev->parent);
struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
int ret;
ret = mutex_lock_interruptible(&w_priv->sysfs_mutex);
if (ret)
return ret;
ret = sysfs_emit(buf, "02.%02u.%02u\n",
w_priv->firmware_rev.major,
w_priv->firmware_rev.minor);
mutex_unlock(&w_priv->sysfs_mutex);
return ret;
}
static DEVICE_ATTR(firmware_version, S_IRUGO, ziirave_wdt_sysfs_show_firm,
NULL);
static ssize_t ziirave_wdt_sysfs_show_boot(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev->parent);
struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
int ret;
ret = mutex_lock_interruptible(&w_priv->sysfs_mutex);
if (ret)
return ret;
ret = sysfs_emit(buf, "01.%02u.%02u\n",
w_priv->bootloader_rev.major,
w_priv->bootloader_rev.minor);
mutex_unlock(&w_priv->sysfs_mutex);
return ret;
}
static DEVICE_ATTR(bootloader_version, S_IRUGO, ziirave_wdt_sysfs_show_boot,
NULL);
static ssize_t ziirave_wdt_sysfs_show_reason(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev->parent);
struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
int ret;
ret = mutex_lock_interruptible(&w_priv->sysfs_mutex);
if (ret)
return ret;
ret = sysfs_emit(buf, "%s\n", ziirave_reasons[w_priv->reset_reason]);
mutex_unlock(&w_priv->sysfs_mutex);
return ret;
}
static DEVICE_ATTR(reset_reason, S_IRUGO, ziirave_wdt_sysfs_show_reason,
NULL);
static ssize_t ziirave_wdt_sysfs_store_firm(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev->parent);
struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
const struct firmware *fw;
int err;
err = request_ihex_firmware(&fw, ZIIRAVE_FW_NAME, dev);
if (err) {
dev_err(&client->dev, "Failed to request ihex firmware\n");
return err;
}
err = mutex_lock_interruptible(&w_priv->sysfs_mutex);
if (err)
goto release_firmware;
err = ziirave_firm_upload(&w_priv->wdd, fw);
if (err) {
dev_err(&client->dev, "The firmware update failed: %d\n", err);
goto unlock_mutex;
}
/* Update firmware version */
err = ziirave_wdt_revision(client, &w_priv->firmware_rev,
ZIIRAVE_WDT_FIRM_VER_MAJOR);
if (err) {
dev_err(&client->dev, "Failed to read firmware version: %d\n",
err);
goto unlock_mutex;
}
dev_info(&client->dev,
"Firmware updated to version 02.%02u.%02u\n",
w_priv->firmware_rev.major, w_priv->firmware_rev.minor);
/* Restore the watchdog timeout */
err = ziirave_wdt_set_timeout(&w_priv->wdd, w_priv->wdd.timeout);
if (err)
dev_err(&client->dev, "Failed to set timeout: %d\n", err);
unlock_mutex:
mutex_unlock(&w_priv->sysfs_mutex);
release_firmware:
release_firmware(fw);
return err ? err : count;
}
static DEVICE_ATTR(update_firmware, S_IWUSR, NULL,
ziirave_wdt_sysfs_store_firm);
static struct attribute *ziirave_wdt_attrs[] = {
&dev_attr_firmware_version.attr,
&dev_attr_bootloader_version.attr,
&dev_attr_reset_reason.attr,
&dev_attr_update_firmware.attr,
NULL
};
ATTRIBUTE_GROUPS(ziirave_wdt);
static int ziirave_wdt_init_duration(struct i2c_client *client)
{
int ret;
if (!reset_duration) {
/* See if the reset pulse duration is provided in an of_node */
if (!client->dev.of_node)
ret = -ENODEV;
else
ret = of_property_read_u32(client->dev.of_node,
"reset-duration-ms",
&reset_duration);
if (ret) {
dev_info(&client->dev,
"No reset pulse duration specified, using default\n");
return 0;
}
}
if (reset_duration < 1 || reset_duration > 255)
return -EINVAL;
dev_info(&client->dev, "Setting reset duration to %dms",
reset_duration);
return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_RESET_DURATION,
reset_duration);
}
static int ziirave_wdt_probe(struct i2c_client *client)
{
int ret;
struct ziirave_wdt_data *w_priv;
int val;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WRITE_BLOCK_DATA))
return -ENODEV;
w_priv = devm_kzalloc(&client->dev, sizeof(*w_priv), GFP_KERNEL);
if (!w_priv)
return -ENOMEM;
mutex_init(&w_priv->sysfs_mutex);
w_priv->wdd.info = &ziirave_wdt_info;
w_priv->wdd.ops = &ziirave_wdt_ops;
w_priv->wdd.min_timeout = ZIIRAVE_TIMEOUT_MIN;
w_priv->wdd.max_timeout = ZIIRAVE_TIMEOUT_MAX;
w_priv->wdd.parent = &client->dev;
w_priv->wdd.groups = ziirave_wdt_groups;
watchdog_init_timeout(&w_priv->wdd, wdt_timeout, &client->dev);
/*
* The default value set in the watchdog should be perfectly valid, so
* pass that in if we haven't provided one via the module parameter or
* of property.
*/
if (w_priv->wdd.timeout == 0) {
val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIMEOUT);
if (val < 0) {
dev_err(&client->dev, "Failed to read timeout\n");
return val;
}
if (val > ZIIRAVE_TIMEOUT_MAX ||
val < ZIIRAVE_TIMEOUT_MIN)
val = ZIIRAVE_TIMEOUT_DEFAULT;
w_priv->wdd.timeout = val;
}
ret = ziirave_wdt_set_timeout(&w_priv->wdd, w_priv->wdd.timeout);
if (ret) {
dev_err(&client->dev, "Failed to set timeout\n");
return ret;
}
dev_info(&client->dev, "Timeout set to %ds\n", w_priv->wdd.timeout);
watchdog_set_nowayout(&w_priv->wdd, nowayout);
i2c_set_clientdata(client, w_priv);
/* If in unconfigured state, set to stopped */
val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_STATE);
if (val < 0) {
dev_err(&client->dev, "Failed to read state\n");
return val;
}
if (val == ZIIRAVE_STATE_INITIAL)
ziirave_wdt_stop(&w_priv->wdd);
ret = ziirave_wdt_init_duration(client);
if (ret) {
dev_err(&client->dev, "Failed to init duration\n");
return ret;
}
ret = ziirave_wdt_revision(client, &w_priv->firmware_rev,
ZIIRAVE_WDT_FIRM_VER_MAJOR);
if (ret) {
dev_err(&client->dev, "Failed to read firmware version\n");
return ret;
}
dev_info(&client->dev,
"Firmware version: 02.%02u.%02u\n",
w_priv->firmware_rev.major, w_priv->firmware_rev.minor);
ret = ziirave_wdt_revision(client, &w_priv->bootloader_rev,
ZIIRAVE_WDT_BOOT_VER_MAJOR);
if (ret) {
dev_err(&client->dev, "Failed to read bootloader version\n");
return ret;
}
dev_info(&client->dev,
"Bootloader version: 01.%02u.%02u\n",
w_priv->bootloader_rev.major, w_priv->bootloader_rev.minor);
w_priv->reset_reason = i2c_smbus_read_byte_data(client,
ZIIRAVE_WDT_RESET_REASON);
if (w_priv->reset_reason < 0) {
dev_err(&client->dev, "Failed to read reset reason\n");
return w_priv->reset_reason;
}
if (w_priv->reset_reason >= ARRAY_SIZE(ziirave_reasons) ||
!ziirave_reasons[w_priv->reset_reason]) {
dev_err(&client->dev, "Invalid reset reason\n");
return -ENODEV;
}
ret = watchdog_register_device(&w_priv->wdd);
return ret;
}
static void ziirave_wdt_remove(struct i2c_client *client)
{
struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
watchdog_unregister_device(&w_priv->wdd);
}
static const struct i2c_device_id ziirave_wdt_id[] = {
{ "rave-wdt", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ziirave_wdt_id);
static const struct of_device_id zrv_wdt_of_match[] = {
{ .compatible = "zii,rave-wdt", },
{ },
};
MODULE_DEVICE_TABLE(of, zrv_wdt_of_match);
static struct i2c_driver ziirave_wdt_driver = {
.driver = {
.name = "ziirave_wdt",
.of_match_table = zrv_wdt_of_match,
},
.probe = ziirave_wdt_probe,
.remove = ziirave_wdt_remove,
.id_table = ziirave_wdt_id,
};
module_i2c_driver(ziirave_wdt_driver);
MODULE_AUTHOR("Martyn Welch <[email protected]");
MODULE_DESCRIPTION("Zodiac Aerospace RAVE Switch Watchdog Processor Driver");
MODULE_LICENSE("GPL");
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