From 33c8cf42152258450f2733c263a8fe8635517c68 Mon Sep 17 00:00:00 2001 From: Christophe Kerello Date: Fri, 14 Dec 2018 10:58:08 +0100 Subject: [PATCH] mtd: rawnand: stm32_fmc2: add polling mode This patch adds the polling mode, a basic mode that do not need any DMA channels. This mode is also useful for debug purpose. Signed-off-by: Christophe Kerello Reviewed-by: Boris Brezillon Signed-off-by: Miquel Raynal --- drivers/mtd/nand/raw/stm32_fmc2_nand.c | 329 ++++++++++++++++++++++--- 1 file changed, 297 insertions(+), 32 deletions(-) diff --git a/drivers/mtd/nand/raw/stm32_fmc2_nand.c b/drivers/mtd/nand/raw/stm32_fmc2_nand.c index c2fc45f7c00b..999ca6a66036 100644 --- a/drivers/mtd/nand/raw/stm32_fmc2_nand.c +++ b/drivers/mtd/nand/raw/stm32_fmc2_nand.c @@ -207,6 +207,12 @@ enum stm32_fmc2_ecc { FMC2_ECC_BCH8 = 8 }; +enum stm32_fmc2_irq_state { + FMC2_IRQ_UNKNOWN = 0, + FMC2_IRQ_BCH, + FMC2_IRQ_SEQ +}; + struct stm32_fmc2_timings { u8 tclr; u8 tar; @@ -241,6 +247,7 @@ struct stm32_fmc2_nfc { phys_addr_t io_phys_addr; phys_addr_t data_phys_addr[FMC2_MAX_CE]; struct clk *clk; + u8 irq_state; struct dma_chan *dma_tx_ch; struct dma_chan *dma_rx_ch; @@ -400,6 +407,17 @@ static void stm32_fmc2_set_buswidth_16(struct stm32_fmc2_nfc *fmc2, bool set) writel_relaxed(pcr, fmc2->io_base + FMC2_PCR); } +/* Enable/disable ECC */ +static void stm32_fmc2_set_ecc(struct stm32_fmc2_nfc *fmc2, bool enable) +{ + u32 pcr = readl(fmc2->io_base + FMC2_PCR); + + pcr &= ~FMC2_PCR_ECCEN; + if (enable) + pcr |= FMC2_PCR_ECCEN; + writel(pcr, fmc2->io_base + FMC2_PCR); +} + /* Enable irq sources in case of the sequencer is used */ static inline void stm32_fmc2_enable_seq_irq(struct stm32_fmc2_nfc *fmc2) { @@ -407,6 +425,8 @@ static inline void stm32_fmc2_enable_seq_irq(struct stm32_fmc2_nfc *fmc2) csqier |= FMC2_CSQIER_TCIE; + fmc2->irq_state = FMC2_IRQ_SEQ; + writel_relaxed(csqier, fmc2->io_base + FMC2_CSQIER); } @@ -418,6 +438,8 @@ static inline void stm32_fmc2_disable_seq_irq(struct stm32_fmc2_nfc *fmc2) csqier &= ~FMC2_CSQIER_TCIE; writel_relaxed(csqier, fmc2->io_base + FMC2_CSQIER); + + fmc2->irq_state = FMC2_IRQ_UNKNOWN; } /* Clear irq sources in case of the sequencer is used */ @@ -426,6 +448,68 @@ static inline void stm32_fmc2_clear_seq_irq(struct stm32_fmc2_nfc *fmc2) writel_relaxed(FMC2_CSQICR_CLEAR_IRQ, fmc2->io_base + FMC2_CSQICR); } +/* Enable irq sources in case of bch is used */ +static inline void stm32_fmc2_enable_bch_irq(struct stm32_fmc2_nfc *fmc2, + int mode) +{ + u32 bchier = readl_relaxed(fmc2->io_base + FMC2_BCHIER); + + if (mode == NAND_ECC_WRITE) + bchier |= FMC2_BCHIER_EPBRIE; + else + bchier |= FMC2_BCHIER_DERIE; + + fmc2->irq_state = FMC2_IRQ_BCH; + + writel_relaxed(bchier, fmc2->io_base + FMC2_BCHIER); +} + +/* Disable irq sources in case of bch is used */ +static inline void stm32_fmc2_disable_bch_irq(struct stm32_fmc2_nfc *fmc2) +{ + u32 bchier = readl_relaxed(fmc2->io_base + FMC2_BCHIER); + + bchier &= ~FMC2_BCHIER_DERIE; + bchier &= ~FMC2_BCHIER_EPBRIE; + + writel_relaxed(bchier, fmc2->io_base + FMC2_BCHIER); + + fmc2->irq_state = FMC2_IRQ_UNKNOWN; +} + +/* Clear irq sources in case of bch is used */ +static inline void stm32_fmc2_clear_bch_irq(struct stm32_fmc2_nfc *fmc2) +{ + writel_relaxed(FMC2_BCHICR_CLEAR_IRQ, fmc2->io_base + FMC2_BCHICR); +} + +/* + * Enable ECC logic and reset syndrome/parity bits previously calculated + * Syndrome/parity bits is cleared by setting the ECCEN bit to 0 + */ +static void stm32_fmc2_hwctl(struct nand_chip *chip, int mode) +{ + struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller); + + stm32_fmc2_set_ecc(fmc2, false); + + if (chip->ecc.strength != FMC2_ECC_HAM) { + u32 pcr = readl_relaxed(fmc2->io_base + FMC2_PCR); + + if (mode == NAND_ECC_WRITE) + pcr |= FMC2_PCR_WEN; + else + pcr &= ~FMC2_PCR_WEN; + writel_relaxed(pcr, fmc2->io_base + FMC2_PCR); + + reinit_completion(&fmc2->complete); + stm32_fmc2_clear_bch_irq(fmc2); + stm32_fmc2_enable_bch_irq(fmc2, mode); + } + + stm32_fmc2_set_ecc(fmc2, true); +} + /* * ECC Hamming calculation * ECC is 3 bytes for 512 bytes of data (supports error correction up to @@ -438,6 +522,30 @@ static inline void stm32_fmc2_ham_set_ecc(const u32 ecc_sta, u8 *ecc) ecc[2] = ecc_sta >> 16; } +static int stm32_fmc2_ham_calculate(struct nand_chip *chip, const u8 *data, + u8 *ecc) +{ + struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller); + u32 sr, heccr; + int ret; + + ret = readl_relaxed_poll_timeout(fmc2->io_base + FMC2_SR, + sr, sr & FMC2_SR_NWRF, 10, 1000); + if (ret) { + dev_err(fmc2->dev, "ham timeout\n"); + return ret; + } + + heccr = readl_relaxed(fmc2->io_base + FMC2_HECCR); + + stm32_fmc2_ham_set_ecc(heccr, ecc); + + /* Disable ECC */ + stm32_fmc2_set_ecc(fmc2, false); + + return 0; +} + static int stm32_fmc2_ham_correct(struct nand_chip *chip, u8 *dat, u8 *read_ecc, u8 *calc_ecc) { @@ -490,6 +598,56 @@ static int stm32_fmc2_ham_correct(struct nand_chip *chip, u8 *dat, return 1; } +/* + * ECC BCH calculation and correction + * ECC is 7/13 bytes for 512 bytes of data (supports error correction up to + * max of 4-bit/8-bit) + */ +static int stm32_fmc2_bch_calculate(struct nand_chip *chip, const u8 *data, + u8 *ecc) +{ + struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller); + u32 bchpbr; + + /* Wait until the BCH code is ready */ + if (!wait_for_completion_timeout(&fmc2->complete, + msecs_to_jiffies(1000))) { + dev_err(fmc2->dev, "bch timeout\n"); + stm32_fmc2_disable_bch_irq(fmc2); + return -ETIMEDOUT; + } + + /* Read parity bits */ + bchpbr = readl_relaxed(fmc2->io_base + FMC2_BCHPBR1); + ecc[0] = bchpbr; + ecc[1] = bchpbr >> 8; + ecc[2] = bchpbr >> 16; + ecc[3] = bchpbr >> 24; + + bchpbr = readl_relaxed(fmc2->io_base + FMC2_BCHPBR2); + ecc[4] = bchpbr; + ecc[5] = bchpbr >> 8; + ecc[6] = bchpbr >> 16; + + if (chip->ecc.strength == FMC2_ECC_BCH8) { + ecc[7] = bchpbr >> 24; + + bchpbr = readl_relaxed(fmc2->io_base + FMC2_BCHPBR3); + ecc[8] = bchpbr; + ecc[9] = bchpbr >> 8; + ecc[10] = bchpbr >> 16; + ecc[11] = bchpbr >> 24; + + bchpbr = readl_relaxed(fmc2->io_base + FMC2_BCHPBR4); + ecc[12] = bchpbr; + } + + /* Disable ECC */ + stm32_fmc2_set_ecc(fmc2, false); + + return 0; +} + /* BCH algorithm correction */ static int stm32_fmc2_bch_decode(int eccsize, u8 *dat, u32 *ecc_sta) { @@ -530,6 +688,94 @@ static int stm32_fmc2_bch_decode(int eccsize, u8 *dat, u32 *ecc_sta) return nb_errs; } +static int stm32_fmc2_bch_correct(struct nand_chip *chip, u8 *dat, + u8 *read_ecc, u8 *calc_ecc) +{ + struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller); + u32 ecc_sta[5]; + + /* Wait until the decoding error is ready */ + if (!wait_for_completion_timeout(&fmc2->complete, + msecs_to_jiffies(1000))) { + dev_err(fmc2->dev, "bch timeout\n"); + stm32_fmc2_disable_bch_irq(fmc2); + return -ETIMEDOUT; + } + + ecc_sta[0] = readl_relaxed(fmc2->io_base + FMC2_BCHDSR0); + ecc_sta[1] = readl_relaxed(fmc2->io_base + FMC2_BCHDSR1); + ecc_sta[2] = readl_relaxed(fmc2->io_base + FMC2_BCHDSR2); + ecc_sta[3] = readl_relaxed(fmc2->io_base + FMC2_BCHDSR3); + ecc_sta[4] = readl_relaxed(fmc2->io_base + FMC2_BCHDSR4); + + /* Disable ECC */ + stm32_fmc2_set_ecc(fmc2, false); + + return stm32_fmc2_bch_decode(chip->ecc.size, dat, ecc_sta); +} + +static int stm32_fmc2_read_page(struct nand_chip *chip, u8 *buf, + int oob_required, int page) +{ + struct mtd_info *mtd = nand_to_mtd(chip); + int ret, i, s, stat, eccsize = chip->ecc.size; + int eccbytes = chip->ecc.bytes; + int eccsteps = chip->ecc.steps; + int eccstrength = chip->ecc.strength; + u8 *p = buf; + u8 *ecc_calc = chip->ecc.calc_buf; + u8 *ecc_code = chip->ecc.code_buf; + unsigned int max_bitflips = 0; + + ret = nand_read_page_op(chip, page, 0, NULL, 0); + if (ret) + return ret; + + for (i = mtd->writesize + FMC2_BBM_LEN, s = 0; s < eccsteps; + s++, i += eccbytes, p += eccsize) { + chip->ecc.hwctl(chip, NAND_ECC_READ); + + /* Read the nand page sector (512 bytes) */ + ret = nand_change_read_column_op(chip, s * eccsize, p, + eccsize, false); + if (ret) + return ret; + + /* Read the corresponding ECC bytes */ + ret = nand_change_read_column_op(chip, i, ecc_code, + eccbytes, false); + if (ret) + return ret; + + /* Correct the data */ + stat = chip->ecc.correct(chip, p, ecc_code, ecc_calc); + if (stat == -EBADMSG) + /* Check for empty pages with bitflips */ + stat = nand_check_erased_ecc_chunk(p, eccsize, + ecc_code, eccbytes, + NULL, 0, + eccstrength); + + if (stat < 0) { + mtd->ecc_stats.failed++; + } else { + mtd->ecc_stats.corrected += stat; + max_bitflips = max_t(unsigned int, max_bitflips, stat); + } + } + + /* Read oob */ + if (oob_required) { + ret = nand_change_read_column_op(chip, mtd->writesize, + chip->oob_poi, mtd->oobsize, + false); + if (ret) + return ret; + } + + return max_bitflips; +} + /* Sequencer read/write configuration */ static void stm32_fmc2_rw_page_init(struct nand_chip *chip, int page, int raw, bool write_data) @@ -967,7 +1213,12 @@ static irqreturn_t stm32_fmc2_irq(int irq, void *dev_id) { struct stm32_fmc2_nfc *fmc2 = (struct stm32_fmc2_nfc *)dev_id; - stm32_fmc2_disable_seq_irq(fmc2); + if (fmc2->irq_state == FMC2_IRQ_SEQ) + /* Sequencer is used */ + stm32_fmc2_disable_seq_irq(fmc2); + else if (fmc2->irq_state == FMC2_IRQ_BCH) + /* BCH is used */ + stm32_fmc2_disable_bch_irq(fmc2); complete(&fmc2->complete); @@ -1356,35 +1607,27 @@ static int stm32_fmc2_dma_setup(struct stm32_fmc2_nfc *fmc2) fmc2->dma_rx_ch = dma_request_slave_channel(fmc2->dev, "rx"); fmc2->dma_ecc_ch = dma_request_slave_channel(fmc2->dev, "ecc"); - if (fmc2->dma_ecc_ch) { - ret = sg_alloc_table(&fmc2->dma_ecc_sg, FMC2_MAX_SG, - GFP_KERNEL); - if (ret) - return ret; - - /* Allocate a buffer to store ECC status registers */ - fmc2->ecc_buf = devm_kzalloc(fmc2->dev, - FMC2_MAX_ECC_BUF_LEN, - GFP_KERNEL); - if (!fmc2->ecc_buf) - return -ENOMEM; - } else { - dev_err(fmc2->dev, "ECC DMA not defined in the device tree\n"); - return -ENOENT; + if (!fmc2->dma_tx_ch || !fmc2->dma_rx_ch || !fmc2->dma_ecc_ch) { + dev_warn(fmc2->dev, "DMAs not defined in the device tree, polling mode is used\n"); + return 0; } - if (fmc2->dma_tx_ch && fmc2->dma_rx_ch) { - ret = sg_alloc_table(&fmc2->dma_data_sg, FMC2_MAX_SG, + ret = sg_alloc_table(&fmc2->dma_ecc_sg, FMC2_MAX_SG, GFP_KERNEL); + if (ret) + return ret; + + /* Allocate a buffer to store ECC status registers */ + fmc2->ecc_buf = devm_kzalloc(fmc2->dev, FMC2_MAX_ECC_BUF_LEN, GFP_KERNEL); - if (ret) - return ret; + if (!fmc2->ecc_buf) + return -ENOMEM; - init_completion(&fmc2->dma_data_complete); - init_completion(&fmc2->dma_ecc_complete); - } else { - dev_err(fmc2->dev, "rx/tx DMA not defined in the device tree\n"); - return -ENOENT; - } + ret = sg_alloc_table(&fmc2->dma_data_sg, FMC2_MAX_SG, GFP_KERNEL); + if (ret) + return ret; + + init_completion(&fmc2->dma_data_complete); + init_completion(&fmc2->dma_ecc_complete); return 0; } @@ -1392,12 +1635,34 @@ static int stm32_fmc2_dma_setup(struct stm32_fmc2_nfc *fmc2) /* NAND callbacks setup */ static void stm32_fmc2_nand_callbacks_setup(struct nand_chip *chip) { - /* Specific callbacks to read/write a page */ - chip->ecc.correct = stm32_fmc2_sequencer_correct; - chip->ecc.write_page = stm32_fmc2_sequencer_write_page; - chip->ecc.read_page = stm32_fmc2_sequencer_read_page; - chip->ecc.write_page_raw = stm32_fmc2_sequencer_write_page_raw; - chip->ecc.read_page_raw = stm32_fmc2_sequencer_read_page_raw; + struct stm32_fmc2_nfc *fmc2 = to_stm32_nfc(chip->controller); + + /* + * Specific callbacks to read/write a page depending on + * the mode (polling/sequencer) and the algo used (Hamming, BCH). + */ + if (fmc2->dma_tx_ch && fmc2->dma_rx_ch && fmc2->dma_ecc_ch) { + /* DMA => use sequencer mode callbacks */ + chip->ecc.correct = stm32_fmc2_sequencer_correct; + chip->ecc.write_page = stm32_fmc2_sequencer_write_page; + chip->ecc.read_page = stm32_fmc2_sequencer_read_page; + chip->ecc.write_page_raw = stm32_fmc2_sequencer_write_page_raw; + chip->ecc.read_page_raw = stm32_fmc2_sequencer_read_page_raw; + } else { + /* No DMA => use polling mode callbacks */ + chip->ecc.hwctl = stm32_fmc2_hwctl; + if (chip->ecc.strength == FMC2_ECC_HAM) { + /* Hamming is used */ + chip->ecc.calculate = stm32_fmc2_ham_calculate; + chip->ecc.correct = stm32_fmc2_ham_correct; + chip->ecc.options |= NAND_ECC_GENERIC_ERASED_CHECK; + } else { + /* BCH is used */ + chip->ecc.calculate = stm32_fmc2_bch_calculate; + chip->ecc.correct = stm32_fmc2_bch_correct; + chip->ecc.read_page = stm32_fmc2_read_page; + } + } /* Specific configurations depending on the algo used */ if (chip->ecc.strength == FMC2_ECC_HAM) -- 2.30.2