diff options
| -rw-r--r-- | drivers/spi/spi-fsi.c | 65 |
1 files changed, 53 insertions, 12 deletions
diff --git a/drivers/spi/spi-fsi.c b/drivers/spi/spi-fsi.c index c31a852b6a3e..a702e9d7d68c 100644 --- a/drivers/spi/spi-fsi.c +++ b/drivers/spi/spi-fsi.c @@ -24,7 +24,8 @@ #define SPI_FSI_BASE 0x70000 #define SPI_FSI_INIT_TIMEOUT_MS 1000 -#define SPI_FSI_MAX_TRANSFER_SIZE 2048 +#define SPI_FSI_MAX_XFR_SIZE 2048 +#define SPI_FSI_MAX_XFR_SIZE_RESTRICTED 32 #define SPI_FSI_ERROR 0x0 #define SPI_FSI_COUNTER_CFG 0x1 @@ -74,6 +75,8 @@ struct fsi_spi { struct device *dev; /* SPI controller device */ struct fsi_device *fsi; /* FSI2SPI CFAM engine device */ u32 base; + size_t max_xfr_size; + bool restricted; }; struct fsi_spi_sequence { @@ -209,8 +212,12 @@ static int fsi_spi_reset(struct fsi_spi *ctx) if (rc) return rc; - return fsi_spi_write_reg(ctx, SPI_FSI_CLOCK_CFG, - SPI_FSI_CLOCK_CFG_RESET2); + rc = fsi_spi_write_reg(ctx, SPI_FSI_CLOCK_CFG, + SPI_FSI_CLOCK_CFG_RESET2); + if (rc) + return rc; + + return fsi_spi_write_reg(ctx, SPI_FSI_STATUS, 0ULL); } static int fsi_spi_sequence_add(struct fsi_spi_sequence *seq, u8 val) @@ -218,8 +225,8 @@ static int fsi_spi_sequence_add(struct fsi_spi_sequence *seq, u8 val) /* * Add the next byte of instruction to the 8-byte sequence register. * Then decrement the counter so that the next instruction will go in - * the right place. Return the number of "slots" left in the sequence - * register. + * the right place. Return the index of the slot we just filled in the + * sequence register. */ seq->data |= (u64)val << seq->bit; seq->bit -= 8; @@ -237,9 +244,11 @@ static int fsi_spi_sequence_transfer(struct fsi_spi *ctx, struct fsi_spi_sequence *seq, struct spi_transfer *transfer) { + bool docfg = false; int loops; int idx; int rc; + u8 val = 0; u8 len = min(transfer->len, 8U); u8 rem = transfer->len % len; u64 cfg = 0ULL; @@ -247,22 +256,42 @@ static int fsi_spi_sequence_transfer(struct fsi_spi *ctx, loops = transfer->len / len; if (transfer->tx_buf) { - idx = fsi_spi_sequence_add(seq, - SPI_FSI_SEQUENCE_SHIFT_OUT(len)); + val = SPI_FSI_SEQUENCE_SHIFT_OUT(len); + idx = fsi_spi_sequence_add(seq, val); + if (rem) rem = SPI_FSI_SEQUENCE_SHIFT_OUT(rem); } else if (transfer->rx_buf) { - idx = fsi_spi_sequence_add(seq, - SPI_FSI_SEQUENCE_SHIFT_IN(len)); + val = SPI_FSI_SEQUENCE_SHIFT_IN(len); + idx = fsi_spi_sequence_add(seq, val); + if (rem) rem = SPI_FSI_SEQUENCE_SHIFT_IN(rem); } else { return -EINVAL; } + if (ctx->restricted) { + const int eidx = rem ? 5 : 6; + + while (loops > 1 && idx <= eidx) { + idx = fsi_spi_sequence_add(seq, val); + loops--; + docfg = true; + } + + if (loops > 1) { + dev_warn(ctx->dev, "No sequencer slots; aborting.\n"); + return -EINVAL; + } + } + if (loops > 1) { fsi_spi_sequence_add(seq, SPI_FSI_SEQUENCE_BRANCH(idx)); + docfg = true; + } + if (docfg) { cfg = SPI_FSI_COUNTER_CFG_LOOPS(loops - 1); if (transfer->rx_buf) cfg |= SPI_FSI_COUNTER_CFG_N2_RX | @@ -273,6 +302,8 @@ static int fsi_spi_sequence_transfer(struct fsi_spi *ctx, rc = fsi_spi_write_reg(ctx, SPI_FSI_COUNTER_CFG, cfg); if (rc) return rc; + } else { + fsi_spi_write_reg(ctx, SPI_FSI_COUNTER_CFG, 0ULL); } if (rem) @@ -429,7 +460,7 @@ static int fsi_spi_transfer_one_message(struct spi_controller *ctlr, /* Sequencer must do shift out (tx) first. */ if (!transfer->tx_buf || - transfer->len > SPI_FSI_MAX_TRANSFER_SIZE) { + transfer->len > (ctx->max_xfr_size + 8)) { rc = -EINVAL; goto error; } @@ -453,7 +484,7 @@ static int fsi_spi_transfer_one_message(struct spi_controller *ctlr, /* Sequencer can only do shift in (rx) after tx. */ if (next->rx_buf) { - if (next->len > SPI_FSI_MAX_TRANSFER_SIZE) { + if (next->len > ctx->max_xfr_size) { rc = -EINVAL; goto error; } @@ -498,7 +529,9 @@ error: static size_t fsi_spi_max_transfer_size(struct spi_device *spi) { - return SPI_FSI_MAX_TRANSFER_SIZE; + struct fsi_spi *ctx = spi_controller_get_devdata(spi->controller); + + return ctx->max_xfr_size; } static int fsi_spi_probe(struct device *dev) @@ -546,6 +579,14 @@ static int fsi_spi_probe(struct device *dev) ctx->fsi = fsi; ctx->base = base + SPI_FSI_BASE; + if (of_device_is_compatible(np, "ibm,fsi2spi-restricted")) { + ctx->restricted = true; + ctx->max_xfr_size = SPI_FSI_MAX_XFR_SIZE_RESTRICTED; + } else { + ctx->restricted = false; + ctx->max_xfr_size = SPI_FSI_MAX_XFR_SIZE; + } + rc = devm_spi_register_controller(dev, ctlr); if (rc) spi_controller_put(ctlr); |