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 <christophe.kerello@st.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
This commit is contained in:
Christophe Kerello 2018-12-14 10:58:08 +01:00 committed by Miquel Raynal
parent 2cd457f328
commit 33c8cf4215

View File

@ -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,
GFP_KERNEL);
if (ret)
return ret;
ret = sg_alloc_table(&fmc2->dma_ecc_sg, FMC2_MAX_SG, GFP_KERNEL);
if (ret)
return ret;
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;
}
/* 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;
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)