static int ms_transfer_data()

in host/rtsx_pci_ms.c [128:197]

• 60 lines of code
• 10 McCabe index (conditional complexity)

static int ms_transfer_data(struct realtek_pci_ms *host, unsigned char data_dir,
		u8 tpc, u8 cfg, struct scatterlist *sg)
{
	struct rtsx_pcr *pcr = host->pcr;
	int err;
	unsigned int length = sg->length;
	u16 sec_cnt = (u16)(length / 512);
	u8 val, trans_mode, dma_dir;
	struct memstick_dev *card = host->msh->card;
	bool pro_card = card->id.type == MEMSTICK_TYPE_PRO;

	dev_dbg(ms_dev(host), "%s: tpc = 0x%02x, data_dir = %s, length = %d\n",
			__func__, tpc, (data_dir == READ) ? "READ" : "WRITE",
			length);

	if (data_dir == READ) {
		dma_dir = DMA_DIR_FROM_CARD;
		trans_mode = pro_card ? MS_TM_AUTO_READ : MS_TM_NORMAL_READ;
	} else {
		dma_dir = DMA_DIR_TO_CARD;
		trans_mode = pro_card ? MS_TM_AUTO_WRITE : MS_TM_NORMAL_WRITE;
	}

	rtsx_pci_init_cmd(pcr);

	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, MS_TPC, 0xFF, tpc);
	if (pro_card) {
		rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, MS_SECTOR_CNT_H,
				0xFF, (u8)(sec_cnt >> 8));
		rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, MS_SECTOR_CNT_L,
				0xFF, (u8)sec_cnt);
	}
	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, MS_TRANS_CFG, 0xFF, cfg);

	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, IRQSTAT0,
			DMA_DONE_INT, DMA_DONE_INT);
	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, DMATC3, 0xFF, (u8)(length >> 24));
	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, DMATC2, 0xFF, (u8)(length >> 16));
	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, DMATC1, 0xFF, (u8)(length >> 8));
	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, DMATC0, 0xFF, (u8)length);
	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, DMACTL,
			0x03 | DMA_PACK_SIZE_MASK, dma_dir | DMA_EN | DMA_512);
	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, CARD_DATA_SOURCE,
			0x01, RING_BUFFER);

	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, MS_TRANSFER,
			0xFF, MS_TRANSFER_START | trans_mode);
	rtsx_pci_add_cmd(pcr, CHECK_REG_CMD, MS_TRANSFER,
			MS_TRANSFER_END, MS_TRANSFER_END);

	rtsx_pci_send_cmd_no_wait(pcr);

	err = rtsx_pci_transfer_data(pcr, sg, 1, data_dir == READ, 10000);
	if (err < 0) {
		ms_clear_error(host);
		return err;
	}

	rtsx_pci_read_register(pcr, MS_TRANS_CFG, &val);
	if (pro_card) {
		if (val & (MS_INT_CMDNK | MS_INT_ERR |
				MS_CRC16_ERR | MS_RDY_TIMEOUT))
			return -EIO;
	} else {
		if (val & (MS_CRC16_ERR | MS_RDY_TIMEOUT))
			return -EIO;
	}

	return 0;
}