// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2015 Zodiac Inflight Innovations * * Author: Martyn Welch <martyn.welch@collabora.co.uk> * * 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/version.h> #include <linux/watchdog.h> #include <asm/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 #define ZIIRAVE_FW_VERSION_FMT "02.%02u.%02u" #define ZIIRAVE_BL_VERSION_FMT "01.%02u.%02u" 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 = "Zodiac RAVE 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 = sprintf(buf, ZIIRAVE_FW_VERSION_FMT, 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 = sprintf(buf, ZIIRAVE_BL_VERSION_FMT, 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 = sprintf(buf, "%s", 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 " ZIIRAVE_FW_VERSION_FMT "\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, const struct i2c_device_id *id) { 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: " ZIIRAVE_FW_VERSION_FMT "\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: " ZIIRAVE_BL_VERSION_FMT "\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 int ziirave_wdt_remove(struct i2c_client *client) { struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client); watchdog_unregister_device(&w_priv->wdd); return 0; } 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 <martyn.welch@collabora.co.uk"); MODULE_DESCRIPTION("Zodiac Aerospace RAVE Switch Watchdog Processor Driver"); MODULE_LICENSE("GPL");