From 2b3cef0fc757bd06ed9b83bd4c436bfa55f47370 Mon Sep 17 00:00:00 2001 From: Brad Bishop Date: Wed, 9 Sep 2020 17:28:52 -0500 Subject: [PATCH 1/6] spi: fsi: Handle 9 to 15 byte transfers lengths The trailing - 8 bytes of transfer data in this size range is no longer ignored. Fixes: bbb6b2f9865b ("spi: Add FSI-attached SPI controller driver") Signed-off-by: Brad Bishop Signed-off-by: Eddie James Reviewed-by: Joel Stanley Signed-off-by: Joel Stanley Link: https://lore.kernel.org/r/20200909222857.28653-2-eajames@linux.ibm.com Signed-off-by: Mark Brown --- drivers/spi/spi-fsi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-fsi.c b/drivers/spi/spi-fsi.c index 37a3e0f8e752..8f64af0140e0 100644 --- a/drivers/spi/spi-fsi.c +++ b/drivers/spi/spi-fsi.c @@ -258,15 +258,15 @@ static int fsi_spi_sequence_transfer(struct fsi_spi *ctx, if (loops > 1) { fsi_spi_sequence_add(seq, SPI_FSI_SEQUENCE_BRANCH(idx)); - if (rem) - fsi_spi_sequence_add(seq, rem); - rc = fsi_spi_write_reg(ctx, SPI_FSI_COUNTER_CFG, SPI_FSI_COUNTER_CFG_LOOPS(loops - 1)); if (rc) return rc; } + if (rem) + fsi_spi_sequence_add(seq, rem); + return 0; } From 0b546bbe9474ff23e6843916ad6d567f703b2396 Mon Sep 17 00:00:00 2001 From: Brad Bishop Date: Wed, 9 Sep 2020 17:28:53 -0500 Subject: [PATCH 2/6] spi: fsi: Fix clock running too fast Use a clock divider tuned to a 200MHz FSI bus frequency (the maximum). Use of the previous divider at 200MHz results in corrupt data from endpoint devices. Ideally the clock divider would be calculated from the FSI clock, but that would require some significant work on the FSI driver. With FSI frequencies slower than 200MHz, the SPI clock will simply run slower, but safely. Signed-off-by: Brad Bishop Signed-off-by: Eddie James Signed-off-by: Joel Stanley Link: https://lore.kernel.org/r/20200909222857.28653-3-eajames@linux.ibm.com Signed-off-by: Mark Brown --- drivers/spi/spi-fsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-fsi.c b/drivers/spi/spi-fsi.c index 8f64af0140e0..559d0ff981f3 100644 --- a/drivers/spi/spi-fsi.c +++ b/drivers/spi/spi-fsi.c @@ -350,7 +350,7 @@ static int fsi_spi_transfer_init(struct fsi_spi *ctx) u64 status = 0ULL; u64 wanted_clock_cfg = SPI_FSI_CLOCK_CFG_ECC_DISABLE | SPI_FSI_CLOCK_CFG_SCK_NO_DEL | - FIELD_PREP(SPI_FSI_CLOCK_CFG_SCK_DIV, 4); + FIELD_PREP(SPI_FSI_CLOCK_CFG_SCK_DIV, 19); end = jiffies + msecs_to_jiffies(SPI_FSI_INIT_TIMEOUT_MS); do { From 7909eebb2bea7fdbb2de0aa794cf29843761ed5b Mon Sep 17 00:00:00 2001 From: Brad Bishop Date: Wed, 9 Sep 2020 17:28:54 -0500 Subject: [PATCH 3/6] spi: fsi: Fix use of the bneq+ sequencer instruction All of the switches in N2_count_control in the counter configuration are required to make the branch if not equal and increment command work. Set them when using bneq+. A side effect of this mode requires a dummy write to TDR when both transmitting and receiving otherwise the controller won't start shifting receive data. It is likely not possible to avoid TDR underrun errors in this mode and they are harmless, so do not check for them. Fixes: bbb6b2f9865b ("spi: Add FSI-attached SPI controller driver") Signed-off-by: Brad Bishop Signed-off-by: Eddie James Reviewed-by: Joel Stanley Signed-off-by: Joel Stanley Link: https://lore.kernel.org/r/20200909222857.28653-4-eajames@linux.ibm.com Signed-off-by: Mark Brown --- drivers/spi/spi-fsi.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-fsi.c b/drivers/spi/spi-fsi.c index 559d0ff981f3..c31a852b6a3e 100644 --- a/drivers/spi/spi-fsi.c +++ b/drivers/spi/spi-fsi.c @@ -29,6 +29,10 @@ #define SPI_FSI_ERROR 0x0 #define SPI_FSI_COUNTER_CFG 0x1 #define SPI_FSI_COUNTER_CFG_LOOPS(x) (((u64)(x) & 0xffULL) << 32) +#define SPI_FSI_COUNTER_CFG_N2_RX BIT_ULL(8) +#define SPI_FSI_COUNTER_CFG_N2_TX BIT_ULL(9) +#define SPI_FSI_COUNTER_CFG_N2_IMPLICIT BIT_ULL(10) +#define SPI_FSI_COUNTER_CFG_N2_RELOAD BIT_ULL(11) #define SPI_FSI_CFG1 0x2 #define SPI_FSI_CLOCK_CFG 0x3 #define SPI_FSI_CLOCK_CFG_MM_ENABLE BIT_ULL(32) @@ -61,7 +65,7 @@ #define SPI_FSI_STATUS_RDR_OVERRUN BIT_ULL(62) #define SPI_FSI_STATUS_RDR_FULL BIT_ULL(63) #define SPI_FSI_STATUS_ANY_ERROR \ - (SPI_FSI_STATUS_ERROR | SPI_FSI_STATUS_TDR_UNDERRUN | \ + (SPI_FSI_STATUS_ERROR | \ SPI_FSI_STATUS_TDR_OVERRUN | SPI_FSI_STATUS_RDR_UNDERRUN | \ SPI_FSI_STATUS_RDR_OVERRUN) #define SPI_FSI_PORT_CTRL 0x9 @@ -238,6 +242,7 @@ static int fsi_spi_sequence_transfer(struct fsi_spi *ctx, int rc; u8 len = min(transfer->len, 8U); u8 rem = transfer->len % len; + u64 cfg = 0ULL; loops = transfer->len / len; @@ -258,8 +263,14 @@ static int fsi_spi_sequence_transfer(struct fsi_spi *ctx, if (loops > 1) { fsi_spi_sequence_add(seq, SPI_FSI_SEQUENCE_BRANCH(idx)); - rc = fsi_spi_write_reg(ctx, SPI_FSI_COUNTER_CFG, - SPI_FSI_COUNTER_CFG_LOOPS(loops - 1)); + cfg = SPI_FSI_COUNTER_CFG_LOOPS(loops - 1); + if (transfer->rx_buf) + cfg |= SPI_FSI_COUNTER_CFG_N2_RX | + SPI_FSI_COUNTER_CFG_N2_TX | + SPI_FSI_COUNTER_CFG_N2_IMPLICIT | + SPI_FSI_COUNTER_CFG_N2_RELOAD; + + rc = fsi_spi_write_reg(ctx, SPI_FSI_COUNTER_CFG, cfg); if (rc) return rc; } @@ -275,6 +286,7 @@ static int fsi_spi_transfer_data(struct fsi_spi *ctx, { int rc = 0; u64 status = 0ULL; + u64 cfg = 0ULL; if (transfer->tx_buf) { int nb; @@ -312,6 +324,16 @@ static int fsi_spi_transfer_data(struct fsi_spi *ctx, u64 in = 0ULL; u8 *rx = transfer->rx_buf; + rc = fsi_spi_read_reg(ctx, SPI_FSI_COUNTER_CFG, &cfg); + if (rc) + return rc; + + if (cfg & SPI_FSI_COUNTER_CFG_N2_IMPLICIT) { + rc = fsi_spi_write_reg(ctx, SPI_FSI_DATA_TX, 0); + if (rc) + return rc; + } + while (transfer->len > recv) { do { rc = fsi_spi_read_reg(ctx, SPI_FSI_STATUS, From 49c9fc1d7c101eceaddb655e4f0e062b0c8f403b Mon Sep 17 00:00:00 2001 From: Eddie James Date: Wed, 9 Sep 2020 17:28:56 -0500 Subject: [PATCH 4/6] spi: fsi: Implement restricted size for certain controllers Some of the FSI-attached SPI controllers cannot use the loop command in programming the sequencer due to security requirements. Check the devicetree compatibility that indicates this condition and restrict the size for these controllers. Also, add more transfers directly in the sequence up to the length of the sequence register. Fixes: bbb6b2f9865b ("spi: Add FSI-attached SPI controller driver") Signed-off-by: Eddie James Reviewed-by: Joel Stanley Signed-off-by: Joel Stanley Link: https://lore.kernel.org/r/20200909222857.28653-6-eajames@linux.ibm.com Signed-off-by: Mark Brown --- drivers/spi/spi-fsi.c | 65 +++++++++++++++++++++++++++++++++++-------- 1 file 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); From 9211a441e60686eec2ebd8f7bd65c4f780416404 Mon Sep 17 00:00:00 2001 From: Eddie James Date: Wed, 9 Sep 2020 17:28:57 -0500 Subject: [PATCH 5/6] spi: fsi: Check mux status before transfers The SPI controllers are not accessible if the mux isn't set. Therefore, check the mux status before starting a transfer and fail out if it isn't set. Signed-off-by: Eddie James Signed-off-by: Joel Stanley Link: https://lore.kernel.org/r/20200909222857.28653-7-eajames@linux.ibm.com Signed-off-by: Mark Brown --- drivers/spi/spi-fsi.c | 40 +++++++++++++++++++++++++++------------- 1 file changed, 27 insertions(+), 13 deletions(-) diff --git a/drivers/spi/spi-fsi.c b/drivers/spi/spi-fsi.c index a702e9d7d68c..8a440c7078ef 100644 --- a/drivers/spi/spi-fsi.c +++ b/drivers/spi/spi-fsi.c @@ -12,6 +12,7 @@ #define FSI_ENGID_SPI 0x23 #define FSI_MBOX_ROOT_CTRL_8 0x2860 +#define FSI_MBOX_ROOT_CTRL_8_SPI_MUX 0xf0000000 #define FSI2SPI_DATA0 0x00 #define FSI2SPI_DATA1 0x04 @@ -84,6 +85,26 @@ struct fsi_spi_sequence { u64 data; }; +static int fsi_spi_check_mux(struct fsi_device *fsi, struct device *dev) +{ + int rc; + u32 root_ctrl_8; + __be32 root_ctrl_8_be; + + rc = fsi_slave_read(fsi->slave, FSI_MBOX_ROOT_CTRL_8, &root_ctrl_8_be, + sizeof(root_ctrl_8_be)); + if (rc) + return rc; + + root_ctrl_8 = be32_to_cpu(root_ctrl_8_be); + dev_dbg(dev, "Root control register 8: %08x\n", root_ctrl_8); + if ((root_ctrl_8 & FSI_MBOX_ROOT_CTRL_8_SPI_MUX) == + FSI_MBOX_ROOT_CTRL_8_SPI_MUX) + return 0; + + return -ENOLINK; +} + static int fsi_spi_check_status(struct fsi_spi *ctx) { int rc; @@ -449,11 +470,15 @@ static int fsi_spi_transfer_init(struct fsi_spi *ctx) static int fsi_spi_transfer_one_message(struct spi_controller *ctlr, struct spi_message *mesg) { - int rc = 0; + int rc; u8 seq_slave = SPI_FSI_SEQUENCE_SEL_SLAVE(mesg->spi->chip_select + 1); struct spi_transfer *transfer; struct fsi_spi *ctx = spi_controller_get_devdata(ctlr); + rc = fsi_spi_check_mux(ctx->fsi, ctx->dev); + if (rc) + return rc; + list_for_each_entry(transfer, &mesg->transfers, transfer_list) { struct fsi_spi_sequence seq; struct spi_transfer *next = NULL; @@ -537,24 +562,13 @@ static size_t fsi_spi_max_transfer_size(struct spi_device *spi) static int fsi_spi_probe(struct device *dev) { int rc; - u32 root_ctrl_8; struct device_node *np; int num_controllers_registered = 0; struct fsi_device *fsi = to_fsi_dev(dev); - /* - * Check the SPI mux before attempting to probe. If the mux isn't set - * then the SPI controllers can't access their slave devices. - */ - rc = fsi_slave_read(fsi->slave, FSI_MBOX_ROOT_CTRL_8, &root_ctrl_8, - sizeof(root_ctrl_8)); + rc = fsi_spi_check_mux(fsi, dev); if (rc) - return rc; - - if (!root_ctrl_8) { - dev_dbg(dev, "SPI mux not set, aborting probe.\n"); return -ENODEV; - } for_each_available_child_of_node(dev->of_node, np) { u32 base; From b0e4dfe93714b21e2fa9b03819b3e99383e5c330 Mon Sep 17 00:00:00 2001 From: Eddie James Date: Wed, 9 Sep 2020 17:28:55 -0500 Subject: [PATCH 6/6] spi: fsi: fsi2spi: Add compatible string for restricted version Add a compatible string for the restricted version of the SPI controller. The restricted version cannot process sequence loop operations and therefore has a smaller transfer size. Signed-off-by: Eddie James Link: https://lore.kernel.org/r/20200909222857.28653-5-eajames@linux.ibm.com Signed-off-by: Mark Brown --- Documentation/devicetree/bindings/fsi/ibm,fsi2spi.yaml | 1 + 1 file changed, 1 insertion(+) diff --git a/Documentation/devicetree/bindings/fsi/ibm,fsi2spi.yaml b/Documentation/devicetree/bindings/fsi/ibm,fsi2spi.yaml index b26d4b4be743..fe39ea4904c1 100644 --- a/Documentation/devicetree/bindings/fsi/ibm,fsi2spi.yaml +++ b/Documentation/devicetree/bindings/fsi/ibm,fsi2spi.yaml @@ -19,6 +19,7 @@ properties: compatible: enum: - ibm,fsi2spi + - ibm,fsi2spi-restricted reg: items: