[PATCH v18 06/12] input: cyapa: add gen3 trackpad device firmware update function support

Dudley Du
2015-01-16T06:35:31Z

Add firmware image update function supported for gen3 trackpad device,
it can be used through sysfs update_fw interface.
TEST=test on Chromebooks.

Signed-off-by: Dudley Du <dudl@cypress.com>
---
drivers/input/mouse/cyapa_gen3.c | 309 +++++++++++++++++++++++++++++++++++++++
1 file changed, 309 insertions(+)

diff --git a/drivers/input/mouse/cyapa_gen3.c b/drivers/input/mouse/cyapa_gen3.c
index 1b62c7d..214d45a 100644
--- a/drivers/input/mouse/cyapa_gen3.c
+++ b/drivers/input/mouse/cyapa_gen3.c
@@ -20,6 +20,7 @@
#include <linux/input/mt.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/unaligned/access_ok.h>
#include "cyapa.h"

@@ -115,6 +116,18 @@ struct cyapa_reg_data {
struct cyapa_touch touches[5];
} __packed;

+struct gen3_write_block_cmd {
+ u8 checksum_seed; /* Always be 0xff */
+ u8 cmd_code; /* command code: 0x39 */
+ u8 key[8]; /* 8-byte security key */
+ __be16 block_num;
+ u8 block_data[CYAPA_FW_BLOCK_SIZE];
+ u8 block_checksum; /* Calculated using bytes 12 - 75 */
+ u8 cmd_checksum; /* Calculated using bytes 0-76 */
+} __packed;
+
+static const u8 security_key[] = {
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
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,
@@ -423,6 +436,87 @@ static int cyapa_gen3_state_parse(struct cyapa *cyapa, u8 *reg_data, int len)
return -EAGAIN;
}

+/*
+ * 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.
+ *
+ * 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_gen3_bl_enter(struct cyapa *cyapa)
+{
+ int error;
+ int waiting_time;
+
+ error = cyapa_poll_state(cyapa, 500);
+ if (error)
+ return error;
+ if (cyapa->state == CYAPA_STATE_BL_IDLE) {
+ /* Already in BL_IDLE. Skipping reset. */
+ return 0;
+ }
+
+ if (cyapa->state != CYAPA_STATE_OP)
+ return -EAGAIN;
+
+ cyapa->operational = false;
+ cyapa->state = CYAPA_STATE_NO_DEVICE;
+ error = cyapa_write_byte(cyapa, CYAPA_CMD_SOFT_RESET, 0x01);
+ if (error)
+ return -EIO;
+
+ usleep_range(25000, 50000);
+ waiting_time = 2000; /* For some shipset, max waiting time is 1~2s. */
+ do {
+ error = cyapa_poll_state(cyapa, 500);
+ if (error) {
+ if (error == -ETIMEDOUT) {
+ waiting_time -= 500;
+ continue;
+ }
+ return error;
+ }
+
+ if ((cyapa->state == CYAPA_STATE_BL_IDLE) &&
+ !(cyapa->status[REG_BL_STATUS] & BL_STATUS_WATCHDOG))
+ break;
+
+ msleep(100);
+ waiting_time -= 100;
+ } while (waiting_time > 0);
+
+ if ((cyapa->state != CYAPA_STATE_BL_IDLE) ||
+ (cyapa->status[REG_BL_STATUS] & BL_STATUS_WATCHDOG))
+ return -EAGAIN;
+
+ return 0;
+}
+
+static int cyapa_gen3_bl_activate(struct cyapa *cyapa)
+{
+ int error;
+
+ error = cyapa_i2c_reg_write_block(cyapa, 0, sizeof(bl_activate),
+ bl_activate);
+ if (error)
+ return error;
+
+ /* Wait for bootloader to activate; takes between 2 and 12 seconds */
+ msleep(2000);
+ error = cyapa_poll_state(cyapa, 11000);
+ if (error)
+ return error;
+ if (cyapa->state != CYAPA_STATE_BL_ACTIVE)
+ return -EAGAIN;
+
+ return 0;
+}
+
static int cyapa_gen3_bl_deactivate(struct cyapa *cyapa)
{
int error;
@@ -483,6 +577,212 @@ static int cyapa_gen3_bl_exit(struct cyapa *cyapa)
return 0;
}

+static u16 cyapa_gen3_csum(const u8 *buf, size_t count)
+{
+ int i;
+ u16 csum = 0;
+
+ for (i = 0; i < count; i++)
+ csum += buf[i];
+
+ return csum;
+}
+
+/*
+ * 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_gen3_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_gen3_csum(&fw->data[2], CYAPA_FW_HDR_SIZE - 2);
+ if (csum != csum_expected) {
+ dev_err(dev, "%s %04x, expected: %04x\n",
+ "invalid firmware header checksum = ",
+ 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_gen3_csum(&fw->data[CYAPA_FW_HDR_SIZE],
+ CYAPA_FW_DATA_SIZE);
+ if (csum != csum_expected) {
+ dev_err(dev, "%s %04x, expected: %04x\n",
+ "invalid firmware header checksum = ",
+ csum, csum_expected);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/*
+ * 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_gen3_write_buffer(struct cyapa *cyapa,
+ const u8 *buf, size_t len)
+{
+ int error;
+ 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);
+
+ error = cyapa_i2c_reg_write_block(cyapa, 0, cmd_len + 1, cmd);
+ if (error)
+ return error;
+ }
+ 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_gen3_write_fw_block(struct cyapa *cyapa,
+ u16 block, const u8 *data)
+{
+ int ret;
+ struct gen3_write_block_cmd write_block_cmd;
+ u8 status[BL_STATUS_SIZE];
+ int tries;
+ u8 bl_status, bl_error;
+
+ /* Set write command and security key bytes. */
+ write_block_cmd.checksum_seed = GEN3_BL_CMD_CHECKSUM_SEED;
+ write_block_cmd.cmd_code = GEN3_BL_CMD_WRITE_BLOCK;
+ memcpy(write_block_cmd.key, security_key, sizeof(security_key));
+ put_unaligned_be16(block, &write_block_cmd.block_num);
+ memcpy(write_block_cmd.block_data, data, CYAPA_FW_BLOCK_SIZE);
+ write_block_cmd.block_checksum = cyapa_gen3_csum(
+ write_block_cmd.block_data, CYAPA_FW_BLOCK_SIZE);
+ write_block_cmd.cmd_checksum = cyapa_gen3_csum((u8 *)&write_block_cmd,
+ sizeof(write_block_cmd) - 1);
+
+ ret = cyapa_gen3_write_buffer(cyapa, (u8 *)&write_block_cmd,
+ sizeof(write_block_cmd));
+ if (ret)
+ return ret;
+
+ /* Wait for write to finish */
+ tries = 11; /* Programming for one block can take about 100ms. */
+ 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;
+ } while ((status[REG_BL_STATUS] & BL_STATUS_BUSY) && --tries);
+
+ /* Ignore WATCHDOG bit and reserved bits. */
+ bl_status = status[REG_BL_STATUS] & ~BL_STATUS_REV_MASK;
+ bl_error = status[REG_BL_ERROR] & ~BL_ERROR_RESERVED;
+
+ if (bl_status & BL_STATUS_BUSY)
+ ret = -ETIMEDOUT;
+ else if (bl_status != BL_STATUS_RUNNING ||
+ bl_error != BL_ERROR_BOOTLOADING)
+ ret = -EIO;
+ else
+ ret = 0;
+
+ return ret;
+}
+
+static int cyapa_gen3_write_blocks(struct cyapa *cyapa,
+ size_t start_block, size_t block_count,
+ const u8 *image_data)
+{
+ int error;
+ int i;
+
+ for (i = 0; i < block_count; i++) {
+ size_t block = start_block + i;
+ size_t addr = i * CYAPA_FW_BLOCK_SIZE;
+ const u8 *data = &image_data[addr];
+
+ error = cyapa_gen3_write_fw_block(cyapa, block, data);
+ if (error)
+ return error;
+ }
+ return 0;
+}
+
+static int cyapa_gen3_do_fw_update(struct cyapa *cyapa,
+ const struct firmware *fw)
+{
+ struct device *dev = &cyapa->client->dev;
+ int error;
+
+ /* First write data, starting at byte 128 of fw->data */
+ error = cyapa_gen3_write_blocks(cyapa,
+ CYAPA_FW_DATA_BLOCK_START, CYAPA_FW_DATA_BLOCK_COUNT,
+ &fw->data[CYAPA_FW_HDR_BLOCK_COUNT * CYAPA_FW_BLOCK_SIZE]);
+ if (error) {
+ dev_err(dev, "FW update aborted, write image: %d\n", error);
+ return error;
+ }
+
+ /* Then write checksum */
+ error = cyapa_gen3_write_blocks(cyapa,
+ CYAPA_FW_HDR_BLOCK_START, CYAPA_FW_HDR_BLOCK_COUNT,
+ &fw->data[0]);
+ if (error) {
+ dev_err(dev, "FW update aborted, write checksum: %d\n", error);
+ return error;
+ }
+
+ return 0;
+}
+
/*
* cyapa_get_wait_time_for_pwr_cmd
*
@@ -791,10 +1091,19 @@ static int cyapa_gen3_irq_handler(struct cyapa *cyapa)
}

static int cyapa_gen3_initialize(struct cyapa *cyapa) { return 0; }
+static int cyapa_gen3_bl_initiate(struct cyapa *cyapa,
+ const struct firmware *fw) { return 0; }
static int cyapa_gen3_empty_output_data(struct cyapa *cyapa,
u8 *buf, int *len, cb_sort func) { return 0; }

const struct cyapa_dev_ops cyapa_gen3_ops = {
+ .check_fw = cyapa_gen3_check_fw,
+ .bl_enter = cyapa_gen3_bl_enter,
+ .bl_activate = cyapa_gen3_bl_activate,
+ .update_fw = cyapa_gen3_do_fw_update,
+ .bl_deactivate = cyapa_gen3_bl_deactivate,
+ .bl_initiate = cyapa_gen3_bl_initiate,
+
.initialize = cyapa_gen3_initialize,

.state_parse = cyapa_gen3_state_parse,
--
1.9.1