Input: atmel_mxt_ts - calculate and check CRC in config file (4ce6fa01) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/input/touchscreen/atmel_mxt_ts.c

+177 −55

Original line number	Diff line number	Diff line
		@@ -48,6 +48,8 @@
		#define MXT_OBJECT_START 0x07

		#define MXT_OBJECT_SIZE 6
		#define MXT_INFO_CHECKSUM_SIZE 3
		#define MXT_MAX_BLOCK_WRITE 256

		/* Object types */
		#define MXT_DEBUG_DIAGNOSTIC_T37 37
		@@ -238,12 +240,15 @@ struct mxt_data {
		unsigned int max_x;
		unsigned int max_y;
		bool in_bootloader;
		u16 mem_size;
		u32 config_crc;
		u32 info_crc;
		u8 bootloader_addr;

		/* Cached parameters from object table */
		u8 T6_reportid;
		u16 T6_address;
		u16 T7_address;
		u8 T9_reportid_min;
		u8 T9_reportid_max;
		u8 T19_reportid;
		@@ -849,6 +854,45 @@ static void mxt_update_crc(struct mxt_data *data, u8 cmd, u8 value)
		mxt_wait_for_completion(data, &data->crc_completion, MXT_CRC_TIMEOUT);
		}

		static void mxt_calc_crc24(u32 *crc, u8 firstbyte, u8 secondbyte)
		{
		static const unsigned int crcpoly = 0x80001B;
		u32 result;
		u32 data_word;

		data_word = (secondbyte << 8) \| firstbyte;
		result = ((*crc << 1) ^ data_word);

		if (result & 0x1000000)
		result ^= crcpoly;

		*crc = result;
		}

		static u32 mxt_calculate_crc(u8 *base, off_t start_off, off_t end_off)
		{
		u32 crc = 0;
		u8 *ptr = base + start_off;
		u8 *last_val = base + end_off - 1;

		if (end_off < start_off)
		return -EINVAL;

		while (ptr < last_val) {
		mxt_calc_crc24(&crc, ptr, (ptr + 1));
		ptr += 2;
		}

		/* if len is odd, fill the last byte with 0 */
		if (ptr == last_val)
		mxt_calc_crc24(&crc, *ptr, 0);

		/* Mask to 24-bit */
		crc &= 0x00FFFFFF;

		return crc;
		}

		/*
		* mxt_update_cfg - download configuration to chip
		*
		@@ -875,9 +919,13 @@ static int mxt_update_cfg(struct mxt_data data, const struct firmware cfg)
		struct mxt_object *object;
		int ret;
		int offset;
		int pos;
		int data_pos;
		int byte_offset;
		int i;
		u32 info_crc, config_crc;
		int cfg_start_ofs;
		u32 info_crc, config_crc, calculated_crc;
		u8 *config_mem;
		size_t config_mem_size;
		unsigned int type, instance, size;
		u8 val;
		u16 reg;
		@@ -890,11 +938,11 @@ static int mxt_update_cfg(struct mxt_data data, const struct firmware cfg)
		goto release;
		}

		pos = strlen(MXT_CFG_MAGIC);
		data_pos = strlen(MXT_CFG_MAGIC);

		/* Load information block and check */
		for (i = 0; i < sizeof(struct mxt_info); i++) {
		ret = sscanf(cfg->data + pos, "%hhx%n",
		ret = sscanf(cfg->data + data_pos, "%hhx%n",
		(unsigned char *)&cfg_info + i,
		&offset);
		if (ret != 1) {
		@@ -903,7 +951,7 @@ static int mxt_update_cfg(struct mxt_data data, const struct firmware cfg)
		goto release;
		}

		pos += offset;
		data_pos += offset;
		}

		if (cfg_info.family_id != data->info.family_id) {
		@@ -918,125 +966,188 @@ static int mxt_update_cfg(struct mxt_data data, const struct firmware cfg)
		goto release;
		}

		if (cfg_info.version != data->info.version)
		dev_err(dev, "Warning: version mismatch!\n");

		if (cfg_info.build != data->info.build)
		dev_err(dev, "Warning: build num mismatch!\n");

		ret = sscanf(cfg->data + pos, "%x%n", &info_crc, &offset);
		/* Read CRCs */
		ret = sscanf(cfg->data + data_pos, "%x%n", &info_crc, &offset);
		if (ret != 1) {
		dev_err(dev, "Bad format: failed to parse Info CRC\n");
		ret = -EINVAL;
		goto release;
		}
		pos += offset;
		data_pos += offset;

		/* Check config CRC */
		ret = sscanf(cfg->data + pos, "%x%n", &config_crc, &offset);
		ret = sscanf(cfg->data + data_pos, "%x%n", &config_crc, &offset);
		if (ret != 1) {
		dev_err(dev, "Bad format: failed to parse Config CRC\n");
		ret = -EINVAL;
		goto release;
		}
		pos += offset;
		data_pos += offset;

		if (data->config_crc == config_crc) {
		dev_dbg(dev, "Config CRC 0x%06X: OK\n", config_crc);
		/*
		* The Info Block CRC is calculated over mxt_info and the object
		* table. If it does not match then we are trying to load the
		* configuration from a different chip or firmware version, so
		* the configuration CRC is invalid anyway.
		*/
		if (info_crc == data->info_crc) {
		if (config_crc == 0 \|\| data->config_crc == 0) {
		dev_info(dev, "CRC zero, attempting to apply config\n");
		} else if (config_crc == data->config_crc) {
		dev_dbg(dev, "Config CRC 0x%06X: OK\n",
		data->config_crc);
		ret = 0;
		goto release;
		}

		} else {
		dev_info(dev, "Config CRC 0x%06X: does not match file 0x%06X\n",
		data->config_crc, config_crc);
		}
		} else {
		dev_warn(dev,
		"Warning: Info CRC error - device=0x%06X file=0x%06X\n",
		data->info_crc, info_crc);
		}

		/* Malloc memory to store configuration */
		cfg_start_ofs = MXT_OBJECT_START +
		data->info.object_num * sizeof(struct mxt_object) +
		MXT_INFO_CHECKSUM_SIZE;
		config_mem_size = data->mem_size - cfg_start_ofs;
		config_mem = kzalloc(config_mem_size, GFP_KERNEL);
		if (!config_mem) {
		dev_err(dev, "Failed to allocate memory\n");
		ret = -ENOMEM;
		goto release;
		}

		while (pos < cfg->size) {
		while (data_pos < cfg->size) {
		/* Read type, instance, length */
		ret = sscanf(cfg->data + pos, "%x %x %x%n",
		ret = sscanf(cfg->data + data_pos, "%x %x %x%n",
		&type, &instance, &size, &offset);
		if (ret == 0) {
		/* EOF */
		ret = 1;
		goto release;
		break;
		} else if (ret != 3) {
		dev_err(dev, "Bad format: failed to parse object\n");
		ret = -EINVAL;
		goto release;
		goto release_mem;
		}
		pos += offset;
		data_pos += offset;

		object = mxt_get_object(data, type);
		if (!object) {
		/* Skip object */
		for (i = 0; i < size; i++) {
		ret = sscanf(cfg->data + pos, "%hhx%n",
		ret = sscanf(cfg->data + data_pos, "%hhx%n",
		&val,
		&offset);
		pos += offset;
		data_pos += offset;
		}
		continue;
		}

		if (size > mxt_obj_size(object)) {
		dev_err(dev, "Discarding %zu byte(s) in T%u\n",
		/*
		* Either we are in fallback mode due to wrong
		* config or config from a later fw version,
		* or the file is corrupt or hand-edited.
		*/
		dev_warn(dev, "Discarding %zu byte(s) in T%u\n",
		size - mxt_obj_size(object), type);
		} else if (mxt_obj_size(object) > size) {
		/*
		* If firmware is upgraded, new bytes may be added to
		* end of objects. It is generally forward compatible
		* to zero these bytes - previous behaviour will be
		* retained. However this does invalidate the CRC and
		* will force fallback mode until the configuration is
		* updated. We warn here but do nothing else - the
		* malloc has zeroed the entire configuration.
		*/
		dev_warn(dev, "Zeroing %zu byte(s) in T%d\n",
		mxt_obj_size(object) - size, type);
		}

		if (instance >= mxt_obj_instances(object)) {
		dev_err(dev, "Object instances exceeded!\n");
		ret = -EINVAL;
		goto release;
		goto release_mem;
		}

		reg = object->start_address + mxt_obj_size(object) * instance;

		for (i = 0; i < size; i++) {
		ret = sscanf(cfg->data + pos, "%hhx%n",
		ret = sscanf(cfg->data + data_pos, "%hhx%n",
		&val,
		&offset);
		if (ret != 1) {
		dev_err(dev, "Bad format in T%d\n", type);
		ret = -EINVAL;
		goto release;
		goto release_mem;
		}
		pos += offset;
		data_pos += offset;

		if (i > mxt_obj_size(object))
		continue;

		ret = mxt_write_reg(data->client, reg + i, val);
		if (ret)
		goto release;
		byte_offset = reg + i - cfg_start_ofs;

		if ((byte_offset >= 0)
		&& (byte_offset <= config_mem_size)) {
		*(config_mem + byte_offset) = val;
		} else {
		dev_err(dev, "Bad object: reg:%d, T%d, ofs=%d\n",
		reg, object->type, byte_offset);
		ret = -EINVAL;
		goto release_mem;
		}
		}
		}

		/*
		* If firmware is upgraded, new bytes may be added to end of
		* objects. It is generally forward compatible to zero these
		* bytes - previous behaviour will be retained. However
		* this does invalidate the CRC and will force a config
		* download every time until the configuration is updated.
		*/
		if (size < mxt_obj_size(object)) {
		dev_info(dev, "Zeroing %zu byte(s) in T%d\n",
		mxt_obj_size(object) - size, type);

		for (i = size + 1; i < mxt_obj_size(object); i++) {
		ret = mxt_write_reg(data->client, reg + i, 0);
		if (ret)
		goto release;
		/* Calculate crc of the received configs (not the raw config file) */
		if (data->T7_address < cfg_start_ofs) {
		dev_err(dev, "Bad T7 address, T7addr = %x, config offset %x\n",
		data->T7_address, cfg_start_ofs);
		ret = 0;
		goto release_mem;
		}

		calculated_crc = mxt_calculate_crc(config_mem,
		data->T7_address - cfg_start_ofs,
		config_mem_size);

		if (config_crc > 0 && (config_crc != calculated_crc))
		dev_warn(dev, "Config CRC error, calculated=%06X, file=%06X\n",
		calculated_crc, config_crc);

		/* Write configuration as blocks */
		byte_offset = 0;
		while (byte_offset < config_mem_size) {
		size = config_mem_size - byte_offset;

		if (size > MXT_MAX_BLOCK_WRITE)
		size = MXT_MAX_BLOCK_WRITE;

		ret = __mxt_write_reg(data->client,
		cfg_start_ofs + byte_offset,
		size, config_mem + byte_offset);
		if (ret != 0) {
		dev_err(dev, "Config write error, ret=%d\n", ret);
		goto release_mem;
		}

		byte_offset += size;
		}

		mxt_update_crc(data, MXT_COMMAND_BACKUPNV, MXT_BACKUP_VALUE);

		ret = mxt_soft_reset(data);
		if (ret)
		goto release;
		goto release_mem;

		dev_info(dev, "Config successfully updated\n");

		release_mem:
		kfree(config_mem);
		release:
		release_firmware(cfg);
		return ret;
		@@ -1099,6 +1210,7 @@ static int mxt_get_object_table(struct mxt_data *data)
		int error;
		int i;
		u8 reportid;
		u16 end_address;

		table_size = data->info.object_num * sizeof(struct mxt_object);
		object_table = kzalloc(table_size, GFP_KERNEL);
		@@ -1116,6 +1228,7 @@ static int mxt_get_object_table(struct mxt_data *data)

		/* Valid Report IDs start counting from 1 */
		reportid = 1;
		data->mem_size = 0;
		for (i = 0; i < data->info.object_num; i++) {
		struct mxt_object *object = object_table + i;
		u8 min_id, max_id;
		@@ -1143,6 +1256,9 @@ static int mxt_get_object_table(struct mxt_data *data)
		data->T6_reportid = min_id;
		data->T6_address = object->start_address;
		break;
		case MXT_GEN_POWER_T7:
		data->T7_address = object->start_address;
		break;
		case MXT_TOUCH_MULTI_T9:
		data->T9_reportid_min = min_id;
		data->T9_reportid_max = max_id;
		@@ -1151,6 +1267,12 @@ static int mxt_get_object_table(struct mxt_data *data)
		data->T19_reportid = min_id;
		break;
		}

		end_address = object->start_address
		+ mxt_obj_size(object) * mxt_obj_instances(object) - 1;

		if (end_address >= data->mem_size)
		data->mem_size = end_address + 1;
		}

		data->object_table = object_table;