Commit 87b26d72 authored by Dudley Du's avatar Dudley Du Committed by Dmitry Torokhov
Browse files

Input: cyapa - add gen3 trackpad device firmware update support 



Add support for firmware image update for gen3 trackpad devices; the
firmware update is initiated by writing to update_fw sysfs attribute.

Signed-off-by: default avatarDudley Du <dudl@cypress.com>
Tested-by: default avatarJeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent c806b0b8

drivers/input/mouse/cyapa_gen3.c

+309 −0
Original line number Diff line number Diff line
@@ -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,