Hello Keguang, I guess I am mostly fine with the driver, it's probably time to merge it. Just a few final changes below, I plan on merging it at -rc1. > + case NAND_CMD_READSTART: > + if (!op->is_read) > + return -EOPNOTSUPP; > + op->cmd_reg = LS1X_NAND_CMD_READ; > + break; > + case NAND_CMD_RNDOUT: > + op->is_change_column = true; > + break; > + case NAND_CMD_RNDOUTSTART: > + if (!op->is_change_column) > + return -EOPNOTSUPP; > + op->cmd_reg = LS1X_NAND_CMD_READ; > + break; > + default: > + dev_err(host->dev, "unsupported opcode: %u\n", opcode); No error message in the normal path. This should be a debug log at most. This function is called in the check_only path. > + return -EOPNOTSUPP; > + } > + > + return 0; > +} ... > +static int ls1x_nand_read_id_type_exec(struct nand_chip *chip, const struct nand_subop *subop) > +{ > + struct ls1x_nand_host *host = nand_get_controller_data(chip); > + struct ls1x_nand_op op = {}; > + int i, ret; > + union { > + char ids[5]; > + struct { > + int idl; > + char idh; > + }; > + } nand_id; > + > + ret = ls1x_nand_misc_type_exec(chip, subop, &op); > + if (ret) { > + dev_err(host->dev, "failed to read ID! %d\n", ret); No print here, it's not useful. > + return ret; > + } > + > + nand_id.idl = readl(host->reg_base + LS1X_NAND_IDL); > + nand_id.idh = readb(host->reg_base + LS1X_NAND_IDH_STATUS); > + > + for (i = 0; i < min(sizeof(nand_id.ids), op.orig_len); i++) > + op.buf[i] = nand_id.ids[sizeof(nand_id.ids) - 1 - i]; > + > + return ret; > +} ... > +static int ls1x_nand_is_valid_cmd(struct device *dev, u8 opcode) > +{ > + if (opcode == NAND_CMD_STATUS || opcode == NAND_CMD_RESET || opcode == NAND_CMD_READID) > + return 0; > + > + dev_err(dev, "unsupported opcode: %x", opcode); Ditto > + > + return -EOPNOTSUPP; > +} > + > +static int ls1x_nand_is_valid_cmd_seq(struct device *dev, u8 opcode1, u8 opcode2) > +{ > + if (opcode1 == NAND_CMD_RNDOUT && opcode2 == NAND_CMD_RNDOUTSTART) > + return 0; > + > + if (opcode1 == NAND_CMD_READ0 && opcode2 == NAND_CMD_READSTART) > + return 0; > + > + if (opcode1 == NAND_CMD_ERASE1 && opcode2 == NAND_CMD_ERASE2) > + return 0; > + > + if (opcode1 == NAND_CMD_SEQIN && opcode2 == NAND_CMD_PAGEPROG) > + return 0; > + > + dev_err(dev, "unsupported opcode sequence: %x %x", opcode1, > opcode2); Ditto > + > + return -EOPNOTSUPP; > +} ... > +static int ls1x_nand_attach_chip(struct nand_chip *chip) > +{ > + struct ls1x_nand_host *host = nand_get_controller_data(chip); > + u64 chipsize = nanddev_target_size(&chip->base); > + int cell_size = 0; > + > + switch (chipsize) { > + case SZ_128M: > + cell_size = 0x0; > + break; > + case SZ_256M: > + cell_size = 0x1; > + break; > + case SZ_512M: > + cell_size = 0x2; > + break; > + case SZ_1G: > + cell_size = 0x3; > + break; > + case SZ_2G: > + cell_size = 0x4; > + break; > + case SZ_4G: > + cell_size = 0x5; > + break; > + case SZ_8G: > + cell_size = 0x6; > + break; > + case SZ_16G: > + cell_size = 0x7; > + break; > + default: > + dev_err(host->dev, "unsupported chip size: %llu MB\n", chipsize); > + return -EOPNOTSUPP; EINVAL > + } > + > + switch (chip->ecc.engine_type) { > + case NAND_ECC_ENGINE_TYPE_NONE: > + dev_info(host->dev, "No ECC\n"); Please drop > + break; > + case NAND_ECC_ENGINE_TYPE_SOFT: > + dev_info(host->dev, "using SW ECC\n"); Drop > + break; > + default: > + dev_err(host->dev, "ECC mode %d not supported\n", > chip->ecc.engine_type); Drop > + return -EINVAL; > + } > + > + /* set cell size */ > + regmap_update_bits(host->regmap, LS1X_NAND_PARAM, LS1X_NAND_CELL_SIZE_MASK, > + FIELD_PREP(LS1X_NAND_CELL_SIZE_MASK, cell_size)); > + > + regmap_update_bits(host->regmap, LS1X_NAND_TIMING, LS1X_NAND_HOLD_CYCLE_MASK, > + FIELD_PREP(LS1X_NAND_HOLD_CYCLE_MASK, host->data->hold_cycle)); > + > + regmap_update_bits(host->regmap, LS1X_NAND_TIMING, LS1X_NAND_WAIT_CYCLE_MASK, > + FIELD_PREP(LS1X_NAND_WAIT_CYCLE_MASK, host->data->wait_cycle)); > + > + chip->ecc.read_page_raw = nand_monolithic_read_page_raw; > + chip->ecc.write_page_raw = nand_monolithic_write_page_raw; > + > + return 0; > +} > + > +static const struct nand_controller_ops ls1x_nand_controller_ops = { > + .exec_op = ls1x_nand_exec_op, > + .attach_chip = ls1x_nand_attach_chip, > +}; > + > +static void ls1x_nand_controller_cleanup(struct ls1x_nand_host *host) > +{ > + if (host->dma_chan) > + dma_release_channel(host->dma_chan); > +} > + > +static int ls1x_nand_controller_init(struct ls1x_nand_host *host) > +{ > + struct device *dev = host->dev; > + struct dma_chan *chan; > + struct dma_slave_config cfg = {}; > + int ret; > + > + host->regmap = devm_regmap_init_mmio(dev, host->reg_base, &ls1x_nand_regmap_config); > + if (IS_ERR(host->regmap)) > + return dev_err_probe(dev, PTR_ERR(host->regmap), "failed to init regmap\n"); > + > + chan = dma_request_chan(dev, "rxtx"); > + if (IS_ERR(chan)) > + return dev_err_probe(dev, PTR_ERR(chan), "failed to request DMA channel\n"); > + host->dma_chan = chan; > + > + cfg.src_addr = host->dma_base; > + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; > + cfg.dst_addr = host->dma_base; > + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; > + ret = dmaengine_slave_config(host->dma_chan, &cfg); > + if (ret) > + return dev_err_probe(dev, ret, "failed to config DMA channel\n"); > + > + init_completion(&host->dma_complete); > + > + dev_dbg(dev, "got %s for %s access\n", > dma_chan_name(host->dma_chan), dev_name(dev)); You can drop this one as well > + > + return 0; > +} Thanks, Miquèl