// SPDX-License-Identifier: GPL-2.0-or-later // Copyright (C) IBM Corporation 2020 #include <linux/bitfield.h> #include <linux/bits.h> #include <linux/fsi.h> #include <linux/jiffies.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> #include <linux/spi/spi.h> #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 #define FSI2SPI_CMD 0x08 #define FSI2SPI_CMD_WRITE BIT(31) #define FSI2SPI_RESET 0x18 #define FSI2SPI_STATUS 0x1c #define FSI2SPI_STATUS_ANY_ERROR BIT(31) #define FSI2SPI_IRQ 0x20 #define SPI_FSI_BASE 0x70000 #define SPI_FSI_INIT_TIMEOUT_MS 1000 #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 #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) #define SPI_FSI_CLOCK_CFG_ECC_DISABLE (BIT_ULL(35) | BIT_ULL(33)) #define SPI_FSI_CLOCK_CFG_RESET1 (BIT_ULL(36) | BIT_ULL(38)) #define SPI_FSI_CLOCK_CFG_RESET2 (BIT_ULL(37) | BIT_ULL(39)) #define SPI_FSI_CLOCK_CFG_MODE (BIT_ULL(41) | BIT_ULL(42)) #define SPI_FSI_CLOCK_CFG_SCK_RECV_DEL GENMASK_ULL(51, 44) #define SPI_FSI_CLOCK_CFG_SCK_NO_DEL BIT_ULL(51) #define SPI_FSI_CLOCK_CFG_SCK_DIV GENMASK_ULL(63, 52) #define SPI_FSI_MMAP 0x4 #define SPI_FSI_DATA_TX 0x5 #define SPI_FSI_DATA_RX 0x6 #define SPI_FSI_SEQUENCE 0x7 #define SPI_FSI_SEQUENCE_STOP 0x00 #define SPI_FSI_SEQUENCE_SEL_SLAVE(x) (0x10 | ((x) & 0xf)) #define SPI_FSI_SEQUENCE_SHIFT_OUT(x) (0x30 | ((x) & 0xf)) #define SPI_FSI_SEQUENCE_SHIFT_IN(x) (0x40 | ((x) & 0xf)) #define SPI_FSI_SEQUENCE_COPY_DATA_TX 0xc0 #define SPI_FSI_SEQUENCE_BRANCH(x) (0xe0 | ((x) & 0xf)) #define SPI_FSI_STATUS 0x8 #define SPI_FSI_STATUS_ERROR \ (GENMASK_ULL(31, 21) | GENMASK_ULL(15, 12)) #define SPI_FSI_STATUS_SEQ_STATE GENMASK_ULL(55, 48) #define SPI_FSI_STATUS_SEQ_STATE_IDLE BIT_ULL(48) #define SPI_FSI_STATUS_TDR_UNDERRUN BIT_ULL(57) #define SPI_FSI_STATUS_TDR_OVERRUN BIT_ULL(58) #define SPI_FSI_STATUS_TDR_FULL BIT_ULL(59) #define SPI_FSI_STATUS_RDR_UNDERRUN BIT_ULL(61) #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_OVERRUN | SPI_FSI_STATUS_RDR_UNDERRUN | \ SPI_FSI_STATUS_RDR_OVERRUN) #define SPI_FSI_PORT_CTRL 0x9 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 { int bit; 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; u32 sts; __be32 sts_be; rc = fsi_device_read(ctx->fsi, FSI2SPI_STATUS, &sts_be, sizeof(sts_be)); if (rc) return rc; sts = be32_to_cpu(sts_be); if (sts & FSI2SPI_STATUS_ANY_ERROR) { dev_err(ctx->dev, "Error with FSI2SPI interface: %08x.\n", sts); return -EIO; } return 0; } static int fsi_spi_read_reg(struct fsi_spi *ctx, u32 offset, u64 *value) { int rc; __be32 cmd_be; __be32 data_be; u32 cmd = offset + ctx->base; *value = 0ULL; if (cmd & FSI2SPI_CMD_WRITE) return -EINVAL; cmd_be = cpu_to_be32(cmd); rc = fsi_device_write(ctx->fsi, FSI2SPI_CMD, &cmd_be, sizeof(cmd_be)); if (rc) return rc; rc = fsi_spi_check_status(ctx); if (rc) return rc; rc = fsi_device_read(ctx->fsi, FSI2SPI_DATA0, &data_be, sizeof(data_be)); if (rc) return rc; *value |= (u64)be32_to_cpu(data_be) << 32; rc = fsi_device_read(ctx->fsi, FSI2SPI_DATA1, &data_be, sizeof(data_be)); if (rc) return rc; *value |= (u64)be32_to_cpu(data_be); dev_dbg(ctx->dev, "Read %02x[%016llx].\n", offset, *value); return 0; } static int fsi_spi_write_reg(struct fsi_spi *ctx, u32 offset, u64 value) { int rc; __be32 cmd_be; __be32 data_be; u32 cmd = offset + ctx->base; if (cmd & FSI2SPI_CMD_WRITE) return -EINVAL; dev_dbg(ctx->dev, "Write %02x[%016llx].\n", offset, value); data_be = cpu_to_be32(upper_32_bits(value)); rc = fsi_device_write(ctx->fsi, FSI2SPI_DATA0, &data_be, sizeof(data_be)); if (rc) return rc; data_be = cpu_to_be32(lower_32_bits(value)); rc = fsi_device_write(ctx->fsi, FSI2SPI_DATA1, &data_be, sizeof(data_be)); if (rc) return rc; cmd_be = cpu_to_be32(cmd | FSI2SPI_CMD_WRITE); rc = fsi_device_write(ctx->fsi, FSI2SPI_CMD, &cmd_be, sizeof(cmd_be)); if (rc) return rc; return fsi_spi_check_status(ctx); } static int fsi_spi_data_in(u64 in, u8 *rx, int len) { int i; int num_bytes = min(len, 8); for (i = 0; i < num_bytes; ++i) rx[i] = (u8)(in >> (8 * ((num_bytes - 1) - i))); return num_bytes; } static int fsi_spi_data_out(u64 *out, const u8 *tx, int len) { int i; int num_bytes = min(len, 8); u8 *out_bytes = (u8 *)out; /* Unused bytes of the tx data should be 0. */ *out = 0ULL; for (i = 0; i < num_bytes; ++i) out_bytes[8 - (i + 1)] = tx[i]; return num_bytes; } static int fsi_spi_reset(struct fsi_spi *ctx) { int rc; dev_dbg(ctx->dev, "Resetting SPI controller.\n"); rc = fsi_spi_write_reg(ctx, SPI_FSI_CLOCK_CFG, SPI_FSI_CLOCK_CFG_RESET1); if (rc) return rc; 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) { /* * 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 index of the slot we just filled in the * sequence register. */ seq->data |= (u64)val << seq->bit; seq->bit -= 8; return ((64 - seq->bit) / 8) - 2; } static void fsi_spi_sequence_init(struct fsi_spi_sequence *seq) { seq->bit = 56; seq->data = 0ULL; } 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; loops = transfer->len / len; if (transfer->tx_buf) { 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) { 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 | 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; } else { fsi_spi_write_reg(ctx, SPI_FSI_COUNTER_CFG, 0ULL); } if (rem) fsi_spi_sequence_add(seq, rem); return 0; } static int fsi_spi_transfer_data(struct fsi_spi *ctx, struct spi_transfer *transfer) { int rc = 0; u64 status = 0ULL; u64 cfg = 0ULL; if (transfer->tx_buf) { int nb; int sent = 0; u64 out = 0ULL; const u8 *tx = transfer->tx_buf; while (transfer->len > sent) { nb = fsi_spi_data_out(&out, &tx[sent], (int)transfer->len - sent); rc = fsi_spi_write_reg(ctx, SPI_FSI_DATA_TX, out); if (rc) return rc; do { rc = fsi_spi_read_reg(ctx, SPI_FSI_STATUS, &status); if (rc) return rc; if (status & SPI_FSI_STATUS_ANY_ERROR) { rc = fsi_spi_reset(ctx); if (rc) return rc; return -EREMOTEIO; } } while (status & SPI_FSI_STATUS_TDR_FULL); sent += nb; } } else if (transfer->rx_buf) { int recv = 0; 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, &status); if (rc) return rc; if (status & SPI_FSI_STATUS_ANY_ERROR) { rc = fsi_spi_reset(ctx); if (rc) return rc; return -EREMOTEIO; } } while (!(status & SPI_FSI_STATUS_RDR_FULL)); rc = fsi_spi_read_reg(ctx, SPI_FSI_DATA_RX, &in); if (rc) return rc; recv += fsi_spi_data_in(in, &rx[recv], (int)transfer->len - recv); } } return 0; } static int fsi_spi_transfer_init(struct fsi_spi *ctx) { int rc; bool reset = false; unsigned long end; u64 seq_state; u64 clock_cfg = 0ULL; 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, 19); end = jiffies + msecs_to_jiffies(SPI_FSI_INIT_TIMEOUT_MS); do { if (time_after(jiffies, end)) return -ETIMEDOUT; rc = fsi_spi_read_reg(ctx, SPI_FSI_STATUS, &status); if (rc) return rc; seq_state = status & SPI_FSI_STATUS_SEQ_STATE; if (status & (SPI_FSI_STATUS_ANY_ERROR | SPI_FSI_STATUS_TDR_FULL | SPI_FSI_STATUS_RDR_FULL)) { if (reset) return -EIO; rc = fsi_spi_reset(ctx); if (rc) return rc; reset = true; continue; } } while (seq_state && (seq_state != SPI_FSI_STATUS_SEQ_STATE_IDLE)); rc = fsi_spi_read_reg(ctx, SPI_FSI_CLOCK_CFG, &clock_cfg); if (rc) return rc; if ((clock_cfg & (SPI_FSI_CLOCK_CFG_MM_ENABLE | SPI_FSI_CLOCK_CFG_ECC_DISABLE | SPI_FSI_CLOCK_CFG_MODE | SPI_FSI_CLOCK_CFG_SCK_RECV_DEL | SPI_FSI_CLOCK_CFG_SCK_DIV)) != wanted_clock_cfg) rc = fsi_spi_write_reg(ctx, SPI_FSI_CLOCK_CFG, wanted_clock_cfg); return rc; } static int fsi_spi_transfer_one_message(struct spi_controller *ctlr, struct spi_message *mesg) { 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; /* Sequencer must do shift out (tx) first. */ if (!transfer->tx_buf || transfer->len > (ctx->max_xfr_size + 8)) { rc = -EINVAL; goto error; } dev_dbg(ctx->dev, "Start tx of %d bytes.\n", transfer->len); rc = fsi_spi_transfer_init(ctx); if (rc < 0) goto error; fsi_spi_sequence_init(&seq); fsi_spi_sequence_add(&seq, seq_slave); rc = fsi_spi_sequence_transfer(ctx, &seq, transfer); if (rc) goto error; if (!list_is_last(&transfer->transfer_list, &mesg->transfers)) { next = list_next_entry(transfer, transfer_list); /* Sequencer can only do shift in (rx) after tx. */ if (next->rx_buf) { if (next->len > ctx->max_xfr_size) { rc = -EINVAL; goto error; } dev_dbg(ctx->dev, "Sequence rx of %d bytes.\n", next->len); rc = fsi_spi_sequence_transfer(ctx, &seq, next); if (rc) goto error; } else { next = NULL; } } fsi_spi_sequence_add(&seq, SPI_FSI_SEQUENCE_SEL_SLAVE(0)); rc = fsi_spi_write_reg(ctx, SPI_FSI_SEQUENCE, seq.data); if (rc) goto error; rc = fsi_spi_transfer_data(ctx, transfer); if (rc) goto error; if (next) { rc = fsi_spi_transfer_data(ctx, next); if (rc) goto error; transfer = next; } } error: mesg->status = rc; spi_finalize_current_message(ctlr); return rc; } static size_t fsi_spi_max_transfer_size(struct spi_device *spi) { struct fsi_spi *ctx = spi_controller_get_devdata(spi->controller); return ctx->max_xfr_size; } static int fsi_spi_probe(struct device *dev) { int rc; struct device_node *np; int num_controllers_registered = 0; struct fsi_device *fsi = to_fsi_dev(dev); rc = fsi_spi_check_mux(fsi, dev); if (rc) return -ENODEV; for_each_available_child_of_node(dev->of_node, np) { u32 base; struct fsi_spi *ctx; struct spi_controller *ctlr; if (of_property_read_u32(np, "reg", &base)) continue; ctlr = spi_alloc_master(dev, sizeof(*ctx)); if (!ctlr) break; ctlr->dev.of_node = np; ctlr->num_chipselect = of_get_available_child_count(np) ?: 1; ctlr->flags = SPI_CONTROLLER_HALF_DUPLEX; ctlr->max_transfer_size = fsi_spi_max_transfer_size; ctlr->transfer_one_message = fsi_spi_transfer_one_message; ctx = spi_controller_get_devdata(ctlr); ctx->dev = &ctlr->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); else num_controllers_registered++; } if (!num_controllers_registered) return -ENODEV; return 0; } static const struct fsi_device_id fsi_spi_ids[] = { { FSI_ENGID_SPI, FSI_VERSION_ANY }, { } }; MODULE_DEVICE_TABLE(fsi, fsi_spi_ids); static struct fsi_driver fsi_spi_driver = { .id_table = fsi_spi_ids, .drv = { .name = "spi-fsi", .bus = &fsi_bus_type, .probe = fsi_spi_probe, }, }; module_fsi_driver(fsi_spi_driver); MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>"); MODULE_DESCRIPTION("FSI attached SPI controller"); MODULE_LICENSE("GPL");