From: Daniel Kurtz <[email protected]> Use the kernel request_firmware API to allow a hotplug script to load new firmware into CYAPA device. When request_firmware is called by a driver, the kernel creates 'loading' and 'data' sysfs entries, and generates a firmware udev event containing the name of a file ("cyapa.bin").
A udev rule can detect this event and use the sysfs entries to provide the driver with the contents of a binary image firmware image. For instance, the gentoo distribution includes /lib/udev/rules.d/50-firmware.rules, which looks in /lib/firmware/ for a file matching the requested filename, and sends the file to the driver using its sysfs entries. Userspace can initiate the firmware update procedure by copying cyapa.bin to /lib/firmware, and then writing anything to the device sysfs attribute: /sys/bus/i2c/devices/7-0067/update_fw Signed-off-by: Daniel Kurtz <[email protected]> Signed-off-by: Benson Leung <[email protected]> --- drivers/input/mouse/cyapa.c | 351 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 351 insertions(+) diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c index a631aca..e622c25 100644 --- a/drivers/input/mouse/cyapa.c +++ b/drivers/input/mouse/cyapa.c @@ -15,6 +15,7 @@ */ #include <linux/delay.h> +#include <linux/firmware.h> #include <linux/i2c.h> #include <linux/input.h> #include <linux/input/mt.h> @@ -116,6 +117,9 @@ #define BL_STATUS_SIZE 3 /* length of bootloader status registers */ #define BLK_HEAD_BYTES 32 +/* Macro for register map group offset. */ +#define CYAPA_REG_MAP_SIZE 256 + #define PRODUCT_ID_SIZE 16 #define QUERY_DATA_SIZE 27 #define REG_PROTOCOL_GEN_QUERY_OFFSET 20 @@ -220,6 +224,8 @@ struct cyapa { int physical_size_y; }; +static const u8 bl_activate[] = { 0x00, 0xff, 0x38, 0x00, 0x01, 0x02, 0x03, + 0x04, 0x05, 0x06, 0x07 }; static const u8 bl_deactivate[] = { 0x00, 0xff, 0x3b, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 }; static const u8 bl_exit[] = { 0x00, 0xff, 0xa5, 0x00, 0x01, 0x02, 0x03, 0x04, @@ -316,6 +322,41 @@ static const struct cyapa_cmd_len cyapa_smbus_cmds[] = { { CYAPA_SMBUS_BLK_HEAD, 16 }, }; +#define CYAPA_FW_NAME "cyapa.bin" +#define CYAPA_FW_BLOCK_SIZE 64 +#define CYAPA_FW_HDR_START 0x0780 +#define CYAPA_FW_HDR_BLOCK_COUNT 2 +#define CYAPA_FW_HDR_BLOCK_START (CYAPA_FW_HDR_START / CYAPA_FW_BLOCK_SIZE) +#define CYAPA_FW_HDR_SIZE (CYAPA_FW_HDR_BLOCK_COUNT * \ + CYAPA_FW_BLOCK_SIZE) +#define CYAPA_FW_DATA_START 0x0800 +#define CYAPA_FW_DATA_BLOCK_COUNT 480 +#define CYAPA_FW_DATA_BLOCK_START (CYAPA_FW_DATA_START / CYAPA_FW_BLOCK_SIZE) +#define CYAPA_FW_DATA_SIZE (CYAPA_FW_DATA_BLOCK_COUNT * \ + CYAPA_FW_BLOCK_SIZE) +#define CYAPA_FW_SIZE (CYAPA_FW_HDR_SIZE + CYAPA_FW_DATA_SIZE) +#define CYAPA_CMD_LEN 16 + +#define BYTE_PER_LINE 8 +void cyapa_dump_data(struct cyapa *cyapa, size_t length, const u8 *data) +{ +#ifdef DEBUG + struct device *dev = &cyapa->client->dev; + int i; + char buf[BYTE_PER_LINE * 3 + 1]; + char *s = buf; + + for (i = 0; i < length; i++) { + s += sprintf(s, " %02x", data[i]); + if ((i + 1) == length || ((i + 1) % BYTE_PER_LINE) == 0) { + dev_dbg(dev, "%s\n", buf); + s = buf; + } + } +#endif +} +#undef BYTE_PER_LINE + static ssize_t cyapa_i2c_reg_read_block(struct cyapa *cyapa, u8 reg, size_t len, u8 *values) { @@ -498,6 +539,75 @@ static int cyapa_poll_state(struct cyapa *cyapa, unsigned int timeout) return (ret == -EAGAIN || ret == -ETIMEDOUT) ? -ETIMEDOUT : ret; } +/* + * Enter bootloader by soft resetting the device. + * + * If device is already in the bootloader, the function just returns. + * Otherwise, reset the device; after reset, device enters bootloader idle + * state immediately. + * + * Also, if device was unregister device from input core. Device will + * re-register after it is detected following resumption of operational mode. + * + * Returns: + * 0 on success + * -EAGAIN device was reset, but is not now in bootloader idle state + * < 0 if the device never responds within the timeout + */ +static int cyapa_bl_enter(struct cyapa *cyapa) +{ + int ret; + + if (cyapa->input) { + disable_irq(cyapa->irq); + input_unregister_device(cyapa->input); + cyapa->input = NULL; + } + + ret = cyapa_get_state(cyapa); + if (ret < 0) + return ret; + if (cyapa->state == CYAPA_STATE_BL_IDLE) + return 0; + + if (cyapa->state != CYAPA_STATE_OP) + return -EAGAIN; + + cyapa->state = CYAPA_STATE_NO_DEVICE; + ret = cyapa_write_byte(cyapa, CYAPA_CMD_SOFT_RESET, 0x01); + if (ret < 0) + return -EIO; + + usleep_range(25000, 50000); + ret = cyapa_get_state(cyapa); + if (ret < 0) + return ret; + if (cyapa->state != CYAPA_STATE_BL_IDLE) + return -EAGAIN; + + return 0; +} + +static int cyapa_bl_activate(struct cyapa *cyapa) +{ + int ret; + + ret = cyapa_i2c_reg_write_block(cyapa, 0, sizeof(bl_activate), + bl_activate); + if (ret < 0) + return ret; + + /* Wait for bootloader to activate; takes between 2 and 12 seconds */ + msleep(2000); + ret = cyapa_poll_state(cyapa, 10000); + if (ret < 0) + return ret; + if (cyapa->state != CYAPA_STATE_BL_ACTIVE) + return -EAGAIN; + + return 0; +} + static int cyapa_bl_deactivate(struct cyapa *cyapa) { int ret; @@ -682,6 +792,154 @@ static int cyapa_check_is_operational(struct cyapa *cyapa) return 0; } +static u16 cyapa_csum(const u8 *buf, size_t count) +{ + int i; + u16 csum = 0; + + for (i = 0; i < count; i++) + csum += buf[i]; + + return csum; +} + +/* + * Write a |len| byte long buffer |buf| to the device, by chopping it up into a + * sequence of smaller |CYAPA_CMD_LEN|-length write commands. + * + * The data bytes for a write command are prepended with the 1-byte offset + * of the data relative to the start of |buf|. + */ +static int cyapa_write_buffer(struct cyapa *cyapa, const u8 *buf, size_t len) +{ + int ret; + size_t i; + unsigned char cmd[CYAPA_CMD_LEN + 1]; + size_t cmd_len; + + for (i = 0; i < len; i += CYAPA_CMD_LEN) { + const u8 *payload = &buf[i]; + cmd_len = (len - i >= CYAPA_CMD_LEN) ? CYAPA_CMD_LEN : len - i; + cmd[0] = i; + memcpy(&cmd[1], payload, cmd_len); + + ret = cyapa_i2c_reg_write_block(cyapa, 0, cmd_len + 1, cmd); + if (ret < 0) + return ret; + } + return 0; +} + +/* + * A firmware block write command writes 64 bytes of data to a single flash + * page in the device. The 78-byte block write command has the format: + * <0xff> <CMD> <Key> <Start> <Data> <Data-Checksum> <CMD Checksum> + * + * <0xff> - every command starts with 0xff + * <CMD> - the write command value is 0x39 + * <Key> - write commands include an 8-byte key: { 00 01 02 03 04 05 06 07 } + * <Block> - Memory Block number (address / 64) (16-bit, big-endian) + * <Data> - 64 bytes of firmware image data + * <Data Checksum> - sum of 64 <Data> bytes, modulo 0xff + * <CMD Checksum> - sum of 77 bytes, from 0xff to <Data Checksum> + * + * Each write command is split into 5 i2c write transactions of up to 16 bytes. + * Each transaction starts with an i2c register offset: (00, 10, 20, 30, 40). + */ +static int cyapa_write_fw_block(struct cyapa *cyapa, u16 block, const u8 *data) +{ + int ret; + u8 cmd[78]; + u8 status[BL_STATUS_SIZE]; + int tries = 3; + + /* set write command and security key bytes. */ + cmd[0] = 0xff; + cmd[1] = 0x39; + cmd[2] = 0x00; + cmd[3] = 0x01; + cmd[4] = 0x02; + cmd[5] = 0x03; + cmd[6] = 0x04; + cmd[7] = 0x05; + cmd[8] = 0x06; + cmd[9] = 0x07; + cmd[10] = block >> 8; + cmd[11] = block; + memcpy(&cmd[12], data, CYAPA_FW_BLOCK_SIZE); + cmd[76] = cyapa_csum(data, CYAPA_FW_BLOCK_SIZE); + cmd[77] = cyapa_csum(cmd, sizeof(cmd) - 1); + + ret = cyapa_write_buffer(cyapa, cmd, sizeof(cmd)); + if (ret) + return ret; + + /* wait for write to finish */ + do { + usleep_range(10000, 20000); + + /* check block write command result status. */ + ret = cyapa_i2c_reg_read_block(cyapa, BL_HEAD_OFFSET, + BL_STATUS_SIZE, status); + if (ret != BL_STATUS_SIZE) + return (ret < 0) ? ret : -EIO; + ret = (status[1] == 0x10 && status[2] == 0x20) ? 0 : -EIO; + } while (--tries && ret); + + return ret; +} + +/* + * Verify the integrity of a CYAPA firmware image file. + * + * The firmware image file is 30848 bytes, composed of 482 64-byte blocks. + * + * The first 2 blocks are the firmware header. + * The next 480 blocks are the firmware image. + * + * The first two bytes of the header hold the header checksum, computed by + * summing the other 126 bytes of the header. + * The last two bytes of the header hold the firmware image checksum, computed + * by summing the 30720 bytes of the image modulo 0xffff. + * + * Both checksums are stored little-endian. + */ +static int cyapa_check_fw(struct cyapa *cyapa, const struct firmware *fw) +{ + struct device *dev = &cyapa->client->dev; + u16 csum; + u16 csum_expected; + + /* Firmware must match exact 30848 bytes = 482 64-byte blocks. */ + if (fw->size != CYAPA_FW_SIZE) { + dev_err(dev, "invalid firmware size = %zu, expected %u.\n", + fw->size, CYAPA_FW_SIZE); + return -EINVAL; + } + + /* Verify header block */ + csum_expected = (fw->data[0] << 8) | fw->data[1]; + csum = cyapa_csum(&fw->data[2], CYAPA_FW_HDR_SIZE - 2); + if (csum != csum_expected) { + dev_err(dev, + "invalid fw header checksum = %04x, expected: %04x\n", + csum, csum_expected); + return -EINVAL; + } + + /* Verify firmware image */ + csum_expected = (fw->data[CYAPA_FW_HDR_SIZE - 2] << 8) | + fw->data[CYAPA_FW_HDR_SIZE - 1]; + csum = cyapa_csum(&fw->data[CYAPA_FW_HDR_SIZE], CYAPA_FW_DATA_SIZE); + if (csum != csum_expected) { + dev_err(dev, + "invalid fw header checksum = %04x, expected: %04x\n", + csum, csum_expected); + return -EINVAL; + } + return 0; +} + static irqreturn_t cyapa_irq(int irq, void *dev_id) { struct cyapa *cyapa = dev_id; @@ -857,6 +1115,94 @@ static void cyapa_detect(struct cyapa *cyapa) } } +static int cyapa_firmware(struct cyapa *cyapa, const char *fw_name) +{ + struct device *dev = &cyapa->client->dev; + int ret; + const struct firmware *fw; + int i; + + ret = request_firmware(&fw, fw_name, dev); + if (ret) { + dev_err(dev, "Could not load firmware from %s, %d\n", + fw_name, ret); + return ret; + } + + ret = cyapa_check_fw(cyapa, fw); + if (ret) { + dev_err(dev, "Invalid CYAPA firmware image: %s\n", fw_name); + goto done; + } + + ret = cyapa_bl_enter(cyapa); + if (ret) + goto err_detect; + + ret = cyapa_bl_activate(cyapa); + if (ret) + goto err_detect; + + /* First write data, starting at byte 128 of fw->data */ + for (i = 0; i < CYAPA_FW_DATA_BLOCK_COUNT; i++) { + size_t block = CYAPA_FW_DATA_BLOCK_START + i; + size_t addr = (i + CYAPA_FW_HDR_BLOCK_COUNT) * + CYAPA_FW_BLOCK_SIZE; + const u8 *data = &fw->data[addr]; + ret = cyapa_write_fw_block(cyapa, block, data); + if (ret) + goto err_detect; + } + + /* Then write checksum */ + for (i = 0; i < CYAPA_FW_HDR_BLOCK_COUNT; i++) { + size_t block = CYAPA_FW_HDR_BLOCK_START + i; + size_t addr = i * CYAPA_FW_BLOCK_SIZE; + const u8 *data = &fw->data[addr]; + ret = cyapa_write_fw_block(cyapa, block, data); + if (ret) + goto err_detect; + } + +err_detect: + cyapa_detect(cyapa); + +done: + release_firmware(fw); + return ret; +} + +/* + * Sysfs Interface. + */ +static ssize_t cyapa_update_fw_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct cyapa *cyapa = dev_get_drvdata(dev); + const char *fw_name = CYAPA_FW_NAME; + int ret; + + ret = cyapa_firmware(cyapa, fw_name); + if (ret) + dev_err(dev, "firmware update failed, %d\n", ret); + else + dev_dbg(dev, "firmware update succeeded\n"); + + return ret ? ret : count; +} + +static DEVICE_ATTR(update_fw, S_IWUSR, NULL, cyapa_update_fw_store); + +static struct attribute *cyapa_sysfs_entries[] = { + &dev_attr_update_fw.attr, + NULL, +}; + +static const struct attribute_group cyapa_sysfs_group = { + .attrs = cyapa_sysfs_entries, +}; + static int cyapa_probe(struct i2c_client *client, const struct i2c_device_id *dev_id) { @@ -902,6 +1248,9 @@ static int cyapa_probe(struct i2c_client *client, goto err_unregister_device; } + if (sysfs_create_group(&client->dev.kobj, &cyapa_sysfs_group)) + dev_warn(dev, "error creating sysfs entries.\n"); + return 0; err_unregister_device: @@ -916,6 +1265,8 @@ static int cyapa_remove(struct i2c_client *client) { struct cyapa *cyapa = i2c_get_clientdata(client); + sysfs_remove_group(&client->dev.kobj, &cyapa_sysfs_group); + free_irq(cyapa->irq, cyapa); input_unregister_device(cyapa->input); cyapa_set_power_mode(cyapa, PWR_MODE_OFF); -- 1.8.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
