diff mbox

[v16,06/12] input: cyapa: add gen3 trackpad device firmware update function support

Message ID 1418896856-15766-7-git-send-email-dudl@cypress.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dudley Du Dec. 18, 2014, 10 a.m. UTC
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 | 288 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 288 insertions(+)
diff mbox

Patch

diff --git a/drivers/input/mouse/cyapa_gen3.c b/drivers/input/mouse/cyapa_gen3.c
index 228fd2d..cd4f1db 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 +436,69 @@  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;
+
+	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->state = CYAPA_STATE_NO_DEVICE;
+	error = cyapa_write_byte(cyapa, CYAPA_CMD_SOFT_RESET, 0x01);
+	if (error)
+		return -EIO;
+
+	usleep_range(25000, 50000);
+	error = cyapa_poll_state(cyapa, 500);
+	if (error)
+		return error;
+	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 +559,212 @@  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
  *
@@ -791,6 +1073,12 @@  static int cyapa_gen3_irq_handler(struct cyapa *cyapa)
 }
 
 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,
+
 	.state_parse = cyapa_gen3_state_parse,
 	.operational_check = cyapa_gen3_do_operational_check,