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Message-ID: <CAFqH_516pCQpSV+Yo8aPyDAVtr62R04otDODFeVBZwcyjx-f3Q@mail.gmail.com>
Date: Thu, 28 Jul 2016 17:27:13 +0200
From: Enric Balletbo Serra <eballetbo@...il.com>
To: Martyn Welch <martyn.welch@...labora.co.uk>
Cc: Enric Balletbo i Serra <enric.balletbo@...labora.com>,
linux-watchdog@...r.kernel.org,
linux-kernel <linux-kernel@...r.kernel.org>,
Wim Van Sebroeck <wim@...ana.be>,
Guenter Roeck <linux@...ck-us.net>,
Martyn Welch <martyn.welch@...labora.com>
Subject: Re: [PATCH v3] watchdog: ziirave_wdt: Add support to upload the firmware.
Hi Martyn,
2016-07-28 16:36 GMT+02:00 Martyn Welch <martyn.welch@...labora.co.uk>:
>
>
> On 28/07/16 11:37, Enric Balletbo i Serra wrote:
>>
>> This patch adds and entry to the sysfs to start firmware upload process
>> on the specified device with the requested firmware.
>>
>> The uploading of the firmware needs only to happen once per firmware
>> upgrade, as the firmware is stored in persistent storage. If the
>> firmware upload or the firmware verification fails then we print and
>> error message and exit.
>>
>> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@...labora.com>
>> ---
>>
>> Changes since v2: (requested by Guenter)
>> - Remove ihex parsing, convert the file into binary before passing it to
>> the
>> kernel (ihex2fw <src.HEX> <dst.fw>).
>> - New binary firmware parsed using the ihex.h helpers.
>> - Protect firmware upgrade with a mutex.
>> - Remove a noisy message.
>> - Remove some unneded memset.
>> - Remove some unnecessary ()
>>
>> Changes since v1: (requested by Martyn)
>> - Remove two defines that are not used.
>> - Fix typo in documentation count -> length
>>
>> drivers/watchdog/ziirave_wdt.c | 363
>> +++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 363 insertions(+)
>>
>> diff --git a/drivers/watchdog/ziirave_wdt.c
>> b/drivers/watchdog/ziirave_wdt.c
>> index fa1efef..81c8545 100644
>> --- a/drivers/watchdog/ziirave_wdt.c
>> +++ b/drivers/watchdog/ziirave_wdt.c
>> @@ -18,7 +18,10 @@
>> * GNU General Public License for more details.
>> */
>>
>> +#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>
>> @@ -36,6 +39,8 @@
>> #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",
>> @@ -50,12 +55,32 @@ static char *ziirave_reasons[] = {"power cycle", "hw
>> watchdog", NULL, NULL,
>> #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 0x1600
>> +#define ZIIRAVE_FIRM_FLASH_MEMORY_END 0x2bbf
>> +
>> +/* Received and ready for next Download packet. */
>> +#define ZIIRAVE_FIRM_DOWNLOAD_ACK 1
>> +/* Currently writing to flash. Retry Download status in a moment! */
>> +#define ZIIRAVE_FIRM_DOWNLOAD_BUSY 2
>> +
>> +/* 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
>> +
>> struct ziirave_wdt_rev {
>> unsigned char major;
>> unsigned char minor;
>> };
>>
>> struct ziirave_wdt_data {
>> + struct mutex sysfs_mutex;
>
>
> I don't think this is the best name for the mutex given that it's only used
> with firmware upload. "firmware_mutex"?ffir
>
Oh, this reminds me that I missed something while rebasing. The idea
was block the sysfs attributes access while a firmware upgrade is in
progress, this is why I named sysfs_mutex. My bad, I'll fix this in
next revision.
>
>> struct watchdog_device wdd;
>> struct ziirave_wdt_rev bootloader_rev;
>> struct ziirave_wdt_rev firmware_rev;
>> @@ -146,6 +171,288 @@ static unsigned int ziirave_wdt_get_timeleft(struct
>> watchdog_device *wdd)
>> return ret;
>> }
>>
>> +static int ziirave_firm_wait_for_ack(struct watchdog_device *wdd)
>> +{
>> + struct i2c_client *client = to_i2c_client(wdd->parent);
>> + int ret;
>> +
>> + do {
>> + usleep_range(5000, 5100);
>> + ret = i2c_smbus_read_byte(client);
>> + if (ret < 0) {
>> + dev_err(&client->dev, "Failed to read byte\n");
>> + return ret;
>> + }
>> + } while (ret == ZIIRAVE_FIRM_DOWNLOAD_BUSY);
>> +
>> + return ret == ZIIRAVE_FIRM_DOWNLOAD_ACK ? 0 : -EIO;
>> +}
>> +
>> +static int ziirave_firm_set_read_addr(struct watchdog_device *wdd, u16
>> addr)
>> +{
>> + struct i2c_client *client = to_i2c_client(wdd->parent);
>> + u8 address[2];
>> +
>> + address[0] = addr & 0xff;
>> + address[1] = (addr >> 8) & 0xff;
>> +
>> + return i2c_smbus_write_block_data(client,
>> +
>> ZIIRAVE_CMD_DOWNLOAD_SET_READ_ADDR,
>> + ARRAY_SIZE(address), address);
>> +}
>> +
>> +static int ziirave_firm_write_block_data(struct watchdog_device *wdd,
>> + u8 command, u8 length, const u8
>> *data,
>> + bool wait_for_ack)
>> +{
>> + struct i2c_client *client = to_i2c_client(wdd->parent);
>> + int ret;
>> +
>> + ret = i2c_smbus_write_block_data(client, command, length, data);
>> +
>> + if (ret) {
>> + dev_err(&client->dev,
>> + "Failed to send command 0x%02x: %d\n", command,
>> ret);
>> + return ret;
>> + }
>> +
>> + if (wait_for_ack)
>> + ret = ziirave_firm_wait_for_ack(wdd);
>> +
>> + return ret;
>> +}
>> +
>> +static int ziirave_firm_write_byte(struct watchdog_device *wdd, u8
>> command,
>> + u8 byte, bool wait_for_ack)
>> +{
>> + return ziirave_firm_write_block_data(wdd, command, 1, &byte,
>> + wait_for_ack);
>> +}
>> +
>> +/*
>> + * 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,
>> + const struct ihex_binrec *rec)
>> +{
>> + struct i2c_client *client = to_i2c_client(wdd->parent);
>> + u8 i, checksum = 0, packet[ZIIRAVE_FIRM_PKT_TOTAL_SIZE];
>> + int ret;
>> + u16 addr;
>> +
>> + memset(packet, 0, ARRAY_SIZE(packet));
>> +
>> + /* Packet length */
>> + packet[0] = (u8)be16_to_cpu(rec->len);
>> + /* Packet address */
>> + addr = (be32_to_cpu(rec->addr) & 0xffff) >> 1;
>> + packet[1] = (u8)(addr & 0xff);
>> + packet[2] = (u8)((addr & 0xff00) >> 8);
>> +
>> + /* Packet data */
>> + if (be16_to_cpu(rec->len) > ZIIRAVE_FIRM_PKT_DATA_SIZE)
>> + return -EMSGSIZE;
>> + memcpy(packet + 3, rec->data, be16_to_cpu(rec->len));
>> +
>> + /* Packet checksum */
>> + for (i = 0; i < ZIIRAVE_FIRM_PKT_TOTAL_SIZE - 1; i++)
>> + checksum += packet[i];
>> + packet[ZIIRAVE_FIRM_PKT_TOTAL_SIZE - 1] = checksum;
>> +
>> + ret = ziirave_firm_write_block_data(wdd,
>> ZIIRAVE_CMD_DOWNLOAD_PACKET,
>> + ARRAY_SIZE(packet), packet,
>> true);
>> + 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_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];
>> + u16 addr;
>> +
>> + for (rec = (void *)fw->data; rec; rec = ihex_next_binrec(rec)) {
>> + /* Zero length marks end of records */
>> + if (!be16_to_cpu(rec->len))
>> + break;
>> +
>> + addr = (be32_to_cpu(rec->addr) & 0xffff) >> 1;
>> + if (addr < ZIIRAVE_FIRM_FLASH_MEMORY_START ||
>> + addr > ZIIRAVE_FIRM_FLASH_MEMORY_END)
>> + 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 < ARRAY_SIZE(data); 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] = (u8)ret;
>> + }
>> +
>> + if (memcmp(data, rec->data, be16_to_cpu(rec->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);
>> + int ret, words_till_page_break;
>> + const struct ihex_binrec *rec;
>> + struct ihex_binrec *rec_new;
>> +
>> + ret = ziirave_firm_write_byte(wdd, ZIIRAVE_CMD_JUMP_TO_BOOTLOADER,
>> 1,
>> + false);
>> + if (ret)
>> + return ret;
>> +
>> + msleep(500);
>> +
>> + ret = ziirave_firm_write_byte(wdd, ZIIRAVE_CMD_DOWNLOAD_START, 1,
>> true);
>> + if (ret)
>> + return ret;
>> +
>> + msleep(500);
>> +
>> + for (rec = (void *)fw->data; rec; rec = ihex_next_binrec(rec)) {
>> + /* Zero length marks end of records */
>> + if (!be16_to_cpu(rec->len))
>> + break;
>> +
>> + /* Check max data size */
>> + if (be16_to_cpu(rec->len) > ZIIRAVE_FIRM_PKT_DATA_SIZE) {
>> + dev_err(&client->dev, "Firmware packet too long
>> (%d)\n",
>> + be16_to_cpu(rec->len));
>> + return -EMSGSIZE;
>> + }
>> +
>> + /* Calculate words till page break */
>> + words_till_page_break = (64 - ((be32_to_cpu(rec->addr) >>
>> 1) &
>> + 0x3f));
>> + if ((be16_to_cpu(rec->len) >> 1) > words_till_page_break)
>> {
>> + /*
>> + * Data in passes page boundary, so we need to
>> split in
>> + * two blocks of data. Create a packet with the
>> first
>> + * block of data.
>> + */
>> + rec_new = kzalloc(sizeof(struct ihex_binrec) +
>> + (words_till_page_break << 1),
>> + GFP_KERNEL);
>> + if (!rec_new)
>> + return -ENOMEM;
>> +
>> + rec_new->len = cpu_to_be16(words_till_page_break
>> << 1);
>> + rec_new->addr = rec->addr;
>> + memcpy(rec_new->data, rec->data,
>> + be16_to_cpu(rec_new->len));
>> +
>> + ret = ziirave_firm_write_pkt(wdd, rec_new);
>> + kfree(rec_new);
>> + if (ret)
>> + return ret;
>> +
>> + /* Create a packet with the second block of data
>> */
>> + rec_new = kzalloc(sizeof(struct ihex_binrec) +
>> + be16_to_cpu(rec->len) -
>> + (words_till_page_break << 1),
>> + GFP_KERNEL);
>> + if (!rec_new)
>> + return -ENOMEM;
>> +
>> + /* Remaining bytes */
>> + rec_new->len = rec->len -
>> + cpu_to_be16(words_till_page_break
>> << 1);
>> +
>> + rec_new->addr = cpu_to_be32(be32_to_cpu(rec->addr)
>> +
>> + (words_till_page_break << 1));
>> +
>> + memcpy(rec_new->data,
>> + rec->data + (words_till_page_break << 1),
>> + be16_to_cpu(rec_new->len));
>> +
>> + ret = ziirave_firm_write_pkt(wdd, rec_new);
>> + kfree(rec_new);
>> + if (ret)
>> + return ret;
>> + } else {
>> + ret = ziirave_firm_write_pkt(wdd, rec);
>> + if (ret)
>> + return ret;
>> + }
>> + }
>> +
>> + /* For end of download, the length field will be set to 0 */
>> + rec_new = kzalloc(sizeof(struct ihex_binrec) + 1, GFP_KERNEL);
>> + if (!rec_new)
>> + return -ENOMEM;
>> +
>> + ret = ziirave_firm_write_pkt(wdd, rec_new);
>> + kfree(rec_new);
>> + 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 = ziirave_firm_write_byte(wdd, ZIIRAVE_CMD_DOWNLOAD_END, 1,
>> false);
>> + if (ret)
>> + return ret;
>> +
>> + /* Reset the processor */
>> + ret = ziirave_firm_write_byte(wdd, ZIIRAVE_CMD_RESET_PROCESSOR, 1,
>> + false);
>> + if (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",
>> @@ -201,10 +508,64 @@ static ssize_t ziirave_wdt_sysfs_show_reason(struct
>> device *dev,
>> 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)
>> +{
>
>
>
> Am I right in thinking firmware upgrade will get triggered whatever is
> written to it? Wouldn't it be safer to only start the upgrade if a specific
> string is written to the sysfs entry? (Performing the upgrade is basically
> going to disable the watchdog is it not?)
>
Yes you're right. And yes, trigger a firmware upgrade whatever is
written to a file doesn't look very safe. Looking at other drivers
that has this upgrade mechanism seems they also trigger the upgrade
just writting something to the file. For example see
drivers/input/touchscreen/atmel_mxt_ts.c. So doesn't seem to be
something standard in the kernel to handle this.
Maybe just check for a string key will make the firmware upgrade more safer.
Before implementing it I'd like to hear other opinions from Guenter
and other people. Thoughts?
Enric
>
>> + 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 = mutex_lock_interruptible(&w_priv->sysfs_mutex);
>> + if (err)
>> + return err;
>> +
>> + err = request_ihex_firmware(&fw, ZIIRAVE_FW_NAME, dev);
>> + if (err) {
>> + dev_err(&client->dev, "Failed to request ihex
>> firmware\n");
>> + goto unlock_sysfs;
>> + }
>> +
>> + err = ziirave_firm_upload(&w_priv->wdd, fw);
>> + if (err) {
>> + dev_err(&client->dev, "The firmware update failed: %d\n",
>> err);
>> + goto release_firmware;
>> + }
>> +
>> + /* 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 release_firmware;
>> + }
>> +
>> + 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);
>> +
>> +release_firmware:
>> + release_firmware(fw);
>> +unlock_sysfs:
>> + mutex_unlock(&w_priv->sysfs_mutex);
>> +
>> + 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);
>> @@ -252,6 +613,8 @@ static int ziirave_wdt_probe(struct i2c_client
>> *client,
>> 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;
>>
>
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