// SPDX-License-Identifier: GPL-2.0-only /* * Designware SPI core controller driver (refer pxa2xx_spi.c) * * Copyright (c) 2009, Intel Corporation. */ #include #include #include #include #include #include #include #include #include #include #include #include "spi-dw.h" #ifdef CONFIG_DEBUG_FS #include #endif /* Slave spi_device related */ struct chip_data { u32 cr0; u32 rx_sample_dly; /* RX sample delay */ }; #ifdef CONFIG_DEBUG_FS #define DW_SPI_DBGFS_REG(_name, _off) \ { \ .name = _name, \ .offset = _off, \ } static const struct debugfs_reg32 dw_spi_dbgfs_regs[] = { DW_SPI_DBGFS_REG("CTRLR0", DW_SPI_CTRLR0), DW_SPI_DBGFS_REG("CTRLR1", DW_SPI_CTRLR1), DW_SPI_DBGFS_REG("SSIENR", DW_SPI_SSIENR), DW_SPI_DBGFS_REG("SER", DW_SPI_SER), DW_SPI_DBGFS_REG("BAUDR", DW_SPI_BAUDR), DW_SPI_DBGFS_REG("TXFTLR", DW_SPI_TXFTLR), DW_SPI_DBGFS_REG("RXFTLR", DW_SPI_RXFTLR), DW_SPI_DBGFS_REG("TXFLR", DW_SPI_TXFLR), DW_SPI_DBGFS_REG("RXFLR", DW_SPI_RXFLR), DW_SPI_DBGFS_REG("SR", DW_SPI_SR), DW_SPI_DBGFS_REG("IMR", DW_SPI_IMR), DW_SPI_DBGFS_REG("ISR", DW_SPI_ISR), DW_SPI_DBGFS_REG("DMACR", DW_SPI_DMACR), DW_SPI_DBGFS_REG("DMATDLR", DW_SPI_DMATDLR), DW_SPI_DBGFS_REG("DMARDLR", DW_SPI_DMARDLR), DW_SPI_DBGFS_REG("RX_SAMPLE_DLY", DW_SPI_RX_SAMPLE_DLY), }; static int dw_spi_debugfs_init(struct dw_spi *dws) { char name[32]; snprintf(name, 32, "dw_spi%d", dws->master->bus_num); dws->debugfs = debugfs_create_dir(name, NULL); if (!dws->debugfs) return -ENOMEM; dws->regset.regs = dw_spi_dbgfs_regs; dws->regset.nregs = ARRAY_SIZE(dw_spi_dbgfs_regs); dws->regset.base = dws->regs; debugfs_create_regset32("registers", 0400, dws->debugfs, &dws->regset); return 0; } static void dw_spi_debugfs_remove(struct dw_spi *dws) { debugfs_remove_recursive(dws->debugfs); } #else static inline int dw_spi_debugfs_init(struct dw_spi *dws) { return 0; } static inline void dw_spi_debugfs_remove(struct dw_spi *dws) { } #endif /* CONFIG_DEBUG_FS */ void dw_spi_set_cs(struct spi_device *spi, bool enable) { struct dw_spi *dws = spi_controller_get_devdata(spi->controller); bool cs_high = !!(spi->mode & SPI_CS_HIGH); /* * DW SPI controller demands any native CS being set in order to * proceed with data transfer. So in order to activate the SPI * communications we must set a corresponding bit in the Slave * Enable register no matter whether the SPI core is configured to * support active-high or active-low CS level. */ if (cs_high == enable) dw_writel(dws, DW_SPI_SER, BIT(spi->chip_select)); else dw_writel(dws, DW_SPI_SER, 0); } EXPORT_SYMBOL_GPL(dw_spi_set_cs); /* Return the max entries we can fill into tx fifo */ static inline u32 tx_max(struct dw_spi *dws) { u32 tx_room, rxtx_gap; tx_room = dws->fifo_len - dw_readl(dws, DW_SPI_TXFLR); /* * Another concern is about the tx/rx mismatch, we * though to use (dws->fifo_len - rxflr - txflr) as * one maximum value for tx, but it doesn't cover the * data which is out of tx/rx fifo and inside the * shift registers. So a control from sw point of * view is taken. */ rxtx_gap = dws->fifo_len - (dws->rx_len - dws->tx_len); return min3((u32)dws->tx_len, tx_room, rxtx_gap); } /* Return the max entries we should read out of rx fifo */ static inline u32 rx_max(struct dw_spi *dws) { return min_t(u32, dws->rx_len, dw_readl(dws, DW_SPI_RXFLR)); } static void dw_writer(struct dw_spi *dws) { u32 max = tx_max(dws); u32 txw = 0; while (max--) { if (dws->tx) { if (dws->n_bytes == 1) txw = *(u8 *)(dws->tx); else if (dws->n_bytes == 2) txw = *(u16 *)(dws->tx); else txw = *(u32 *)(dws->tx); dws->tx += dws->n_bytes; } dw_write_io_reg(dws, DW_SPI_DR, txw); --dws->tx_len; } } static void dw_reader(struct dw_spi *dws) { u32 max = rx_max(dws); u32 rxw; while (max--) { rxw = dw_read_io_reg(dws, DW_SPI_DR); if (dws->rx) { if (dws->n_bytes == 1) *(u8 *)(dws->rx) = rxw; else if (dws->n_bytes == 2) *(u16 *)(dws->rx) = rxw; else *(u32 *)(dws->rx) = rxw; dws->rx += dws->n_bytes; } --dws->rx_len; } } int dw_spi_check_status(struct dw_spi *dws, bool raw) { u32 irq_status; int ret = 0; if (raw) irq_status = dw_readl(dws, DW_SPI_RISR); else irq_status = dw_readl(dws, DW_SPI_ISR); if (irq_status & SPI_INT_RXOI) { dev_err(&dws->master->dev, "RX FIFO overflow detected\n"); ret = -EIO; } if (irq_status & SPI_INT_RXUI) { dev_err(&dws->master->dev, "RX FIFO underflow detected\n"); ret = -EIO; } if (irq_status & SPI_INT_TXOI) { dev_err(&dws->master->dev, "TX FIFO overflow detected\n"); ret = -EIO; } /* Generically handle the erroneous situation */ if (ret) { spi_reset_chip(dws); if (dws->master->cur_msg) dws->master->cur_msg->status = ret; } return ret; } EXPORT_SYMBOL_GPL(dw_spi_check_status); static irqreturn_t dw_spi_transfer_handler(struct dw_spi *dws) { u16 irq_status = dw_readl(dws, DW_SPI_ISR); if (dw_spi_check_status(dws, false)) { spi_finalize_current_transfer(dws->master); return IRQ_HANDLED; } /* * Read data from the Rx FIFO every time we've got a chance executing * this method. If there is nothing left to receive, terminate the * procedure. Otherwise adjust the Rx FIFO Threshold level if it's a * final stage of the transfer. By doing so we'll get the next IRQ * right when the leftover incoming data is received. */ dw_reader(dws); if (!dws->rx_len) { spi_mask_intr(dws, 0xff); spi_finalize_current_transfer(dws->master); } else if (dws->rx_len <= dw_readl(dws, DW_SPI_RXFTLR)) { dw_writel(dws, DW_SPI_RXFTLR, dws->rx_len - 1); } /* * Send data out if Tx FIFO Empty IRQ is received. The IRQ will be * disabled after the data transmission is finished so not to * have the TXE IRQ flood at the final stage of the transfer. */ if (irq_status & SPI_INT_TXEI) { dw_writer(dws); if (!dws->tx_len) spi_mask_intr(dws, SPI_INT_TXEI); } return IRQ_HANDLED; } static irqreturn_t dw_spi_irq(int irq, void *dev_id) { struct spi_controller *master = dev_id; struct dw_spi *dws = spi_controller_get_devdata(master); u16 irq_status = dw_readl(dws, DW_SPI_ISR) & 0x3f; if (!irq_status) return IRQ_NONE; if (!master->cur_msg) { spi_mask_intr(dws, 0xff); return IRQ_HANDLED; } return dws->transfer_handler(dws); } static u32 dw_spi_prepare_cr0(struct dw_spi *dws, struct spi_device *spi) { u32 cr0 = 0; if (!(dws->caps & DW_SPI_CAP_DWC_SSI)) { /* CTRLR0[ 5: 4] Frame Format */ cr0 |= SSI_MOTO_SPI << SPI_FRF_OFFSET; /* * SPI mode (SCPOL|SCPH) * CTRLR0[ 6] Serial Clock Phase * CTRLR0[ 7] Serial Clock Polarity */ cr0 |= ((spi->mode & SPI_CPOL) ? 1 : 0) << SPI_SCOL_OFFSET; cr0 |= ((spi->mode & SPI_CPHA) ? 1 : 0) << SPI_SCPH_OFFSET; /* CTRLR0[11] Shift Register Loop */ cr0 |= ((spi->mode & SPI_LOOP) ? 1 : 0) << SPI_SRL_OFFSET; } else { /* CTRLR0[ 7: 6] Frame Format */ cr0 |= SSI_MOTO_SPI << DWC_SSI_CTRLR0_FRF_OFFSET; /* * SPI mode (SCPOL|SCPH) * CTRLR0[ 8] Serial Clock Phase * CTRLR0[ 9] Serial Clock Polarity */ cr0 |= ((spi->mode & SPI_CPOL) ? 1 : 0) << DWC_SSI_CTRLR0_SCPOL_OFFSET; cr0 |= ((spi->mode & SPI_CPHA) ? 1 : 0) << DWC_SSI_CTRLR0_SCPH_OFFSET; /* CTRLR0[13] Shift Register Loop */ cr0 |= ((spi->mode & SPI_LOOP) ? 1 : 0) << DWC_SSI_CTRLR0_SRL_OFFSET; if (dws->caps & DW_SPI_CAP_KEEMBAY_MST) cr0 |= DWC_SSI_CTRLR0_KEEMBAY_MST; } return cr0; } void dw_spi_update_config(struct dw_spi *dws, struct spi_device *spi, struct dw_spi_cfg *cfg) { struct chip_data *chip = spi_get_ctldata(spi); u32 cr0 = chip->cr0; u32 speed_hz; u16 clk_div; /* CTRLR0[ 4/3: 0] or CTRLR0[ 20: 16] Data Frame Size */ cr0 |= (cfg->dfs - 1) << dws->dfs_offset; if (!(dws->caps & DW_SPI_CAP_DWC_SSI)) /* CTRLR0[ 9:8] Transfer Mode */ cr0 |= cfg->tmode << SPI_TMOD_OFFSET; else /* CTRLR0[11:10] Transfer Mode */ cr0 |= cfg->tmode << DWC_SSI_CTRLR0_TMOD_OFFSET; dw_writel(dws, DW_SPI_CTRLR0, cr0); if (cfg->tmode == SPI_TMOD_EPROMREAD || cfg->tmode == SPI_TMOD_RO) dw_writel(dws, DW_SPI_CTRLR1, cfg->ndf ? cfg->ndf - 1 : 0); /* Note DW APB SSI clock divider doesn't support odd numbers */ clk_div = (DIV_ROUND_UP(dws->max_freq, cfg->freq) + 1) & 0xfffe; speed_hz = dws->max_freq / clk_div; if (dws->current_freq != speed_hz) { spi_set_clk(dws, clk_div); dws->current_freq = speed_hz; } /* Update RX sample delay if required */ if (dws->cur_rx_sample_dly != chip->rx_sample_dly) { dw_writel(dws, DW_SPI_RX_SAMPLE_DLY, chip->rx_sample_dly); dws->cur_rx_sample_dly = chip->rx_sample_dly; } } EXPORT_SYMBOL_GPL(dw_spi_update_config); static void dw_spi_irq_setup(struct dw_spi *dws) { u16 level; u8 imask; /* * Originally Tx and Rx data lengths match. Rx FIFO Threshold level * will be adjusted at the final stage of the IRQ-based SPI transfer * execution so not to lose the leftover of the incoming data. */ level = min_t(unsigned int, dws->fifo_len / 2, dws->tx_len); dw_writel(dws, DW_SPI_TXFTLR, level); dw_writel(dws, DW_SPI_RXFTLR, level - 1); dws->transfer_handler = dw_spi_transfer_handler; imask = SPI_INT_TXEI | SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI | SPI_INT_RXFI; spi_umask_intr(dws, imask); } /* * The iterative procedure of the poll-based transfer is simple: write as much * as possible to the Tx FIFO, wait until the pending to receive data is ready * to be read, read it from the Rx FIFO and check whether the performed * procedure has been successful. * * Note this method the same way as the IRQ-based transfer won't work well for * the SPI devices connected to the controller with native CS due to the * automatic CS assertion/de-assertion. */ static int dw_spi_poll_transfer(struct dw_spi *dws, struct spi_transfer *transfer) { struct spi_delay delay; u16 nbits; int ret; delay.unit = SPI_DELAY_UNIT_SCK; nbits = dws->n_bytes * BITS_PER_BYTE; do { dw_writer(dws); delay.value = nbits * (dws->rx_len - dws->tx_len); spi_delay_exec(&delay, transfer); dw_reader(dws); ret = dw_spi_check_status(dws, true); if (ret) return ret; } while (dws->rx_len); return 0; } static int dw_spi_transfer_one(struct spi_controller *master, struct spi_device *spi, struct spi_transfer *transfer) { struct dw_spi *dws = spi_controller_get_devdata(master); struct dw_spi_cfg cfg = { .tmode = SPI_TMOD_TR, .dfs = transfer->bits_per_word, .freq = transfer->speed_hz, }; int ret; dws->dma_mapped = 0; dws->n_bytes = roundup_pow_of_two(DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE)); dws->tx = (void *)transfer->tx_buf; dws->tx_len = transfer->len / dws->n_bytes; dws->rx = transfer->rx_buf; dws->rx_len = dws->tx_len; /* Ensure the data above is visible for all CPUs */ smp_mb(); spi_enable_chip(dws, 0); dw_spi_update_config(dws, spi, &cfg); transfer->effective_speed_hz = dws->current_freq; /* Check if current transfer is a DMA transaction */ if (master->can_dma && master->can_dma(master, spi, transfer)) dws->dma_mapped = master->cur_msg_mapped; /* For poll mode just disable all interrupts */ spi_mask_intr(dws, 0xff); if (dws->dma_mapped) { ret = dws->dma_ops->dma_setup(dws, transfer); if (ret) return ret; } spi_enable_chip(dws, 1); if (dws->dma_mapped) return dws->dma_ops->dma_transfer(dws, transfer); else if (dws->irq == IRQ_NOTCONNECTED) return dw_spi_poll_transfer(dws, transfer); dw_spi_irq_setup(dws); return 1; } static void dw_spi_handle_err(struct spi_controller *master, struct spi_message *msg) { struct dw_spi *dws = spi_controller_get_devdata(master); if (dws->dma_mapped) dws->dma_ops->dma_stop(dws); spi_reset_chip(dws); } static int dw_spi_adjust_mem_op_size(struct spi_mem *mem, struct spi_mem_op *op) { if (op->data.dir == SPI_MEM_DATA_IN) op->data.nbytes = clamp_val(op->data.nbytes, 0, SPI_NDF_MASK + 1); return 0; } static bool dw_spi_supports_mem_op(struct spi_mem *mem, const struct spi_mem_op *op) { if (op->data.buswidth > 1 || op->addr.buswidth > 1 || op->dummy.buswidth > 1 || op->cmd.buswidth > 1) return false; return spi_mem_default_supports_op(mem, op); } static int dw_spi_init_mem_buf(struct dw_spi *dws, const struct spi_mem_op *op) { unsigned int i, j, len; u8 *out; /* * Calculate the total length of the EEPROM command transfer and * either use the pre-allocated buffer or create a temporary one. */ len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes; if (op->data.dir == SPI_MEM_DATA_OUT) len += op->data.nbytes; if (len <= SPI_BUF_SIZE) { out = dws->buf; } else { out = kzalloc(len, GFP_KERNEL); if (!out) return -ENOMEM; } /* * Collect the operation code, address and dummy bytes into the single * buffer. If it's a transfer with data to be sent, also copy it into the * single buffer in order to speed the data transmission up. */ for (i = 0; i < op->cmd.nbytes; ++i) out[i] = SPI_GET_BYTE(op->cmd.opcode, op->cmd.nbytes - i - 1); for (j = 0; j < op->addr.nbytes; ++i, ++j) out[i] = SPI_GET_BYTE(op->addr.val, op->addr.nbytes - j - 1); for (j = 0; j < op->dummy.nbytes; ++i, ++j) out[i] = 0x0; if (op->data.dir == SPI_MEM_DATA_OUT) memcpy(&out[i], op->data.buf.out, op->data.nbytes); dws->n_bytes = 1; dws->tx = out; dws->tx_len = len; if (op->data.dir == SPI_MEM_DATA_IN) { dws->rx = op->data.buf.in; dws->rx_len = op->data.nbytes; } else { dws->rx = NULL; dws->rx_len = 0; } return 0; } static void dw_spi_free_mem_buf(struct dw_spi *dws) { if (dws->tx != dws->buf) kfree(dws->tx); } static int dw_spi_write_then_read(struct dw_spi *dws, struct spi_device *spi) { u32 room, entries, sts; unsigned int len; u8 *buf; /* * At initial stage we just pre-fill the Tx FIFO in with no rush, * since native CS hasn't been enabled yet and the automatic data * transmission won't start til we do that. */ len = min(dws->fifo_len, dws->tx_len); buf = dws->tx; while (len--) dw_write_io_reg(dws, DW_SPI_DR, *buf++); /* * After setting any bit in the SER register the transmission will * start automatically. We have to keep up with that procedure * otherwise the CS de-assertion will happen whereupon the memory * operation will be pre-terminated. */ len = dws->tx_len - ((void *)buf - dws->tx); dw_spi_set_cs(spi, false); while (len) { entries = readl_relaxed(dws->regs + DW_SPI_TXFLR); if (!entries) { dev_err(&dws->master->dev, "CS de-assertion on Tx\n"); return -EIO; } room = min(dws->fifo_len - entries, len); for (; room; --room, --len) dw_write_io_reg(dws, DW_SPI_DR, *buf++); } /* * Data fetching will start automatically if the EEPROM-read mode is * activated. We have to keep up with the incoming data pace to * prevent the Rx FIFO overflow causing the inbound data loss. */ len = dws->rx_len; buf = dws->rx; while (len) { entries = readl_relaxed(dws->regs + DW_SPI_RXFLR); if (!entries) { sts = readl_relaxed(dws->regs + DW_SPI_RISR); if (sts & SPI_INT_RXOI) { dev_err(&dws->master->dev, "FIFO overflow on Rx\n"); return -EIO; } continue; } entries = min(entries, len); for (; entries; --entries, --len) *buf++ = dw_read_io_reg(dws, DW_SPI_DR); } return 0; } static inline bool dw_spi_ctlr_busy(struct dw_spi *dws) { return dw_readl(dws, DW_SPI_SR) & SR_BUSY; } static int dw_spi_wait_mem_op_done(struct dw_spi *dws) { int retry = SPI_WAIT_RETRIES; struct spi_delay delay; unsigned long ns, us; u32 nents; nents = dw_readl(dws, DW_SPI_TXFLR); ns = NSEC_PER_SEC / dws->current_freq * nents; ns *= dws->n_bytes * BITS_PER_BYTE; if (ns <= NSEC_PER_USEC) { delay.unit = SPI_DELAY_UNIT_NSECS; delay.value = ns; } else { us = DIV_ROUND_UP(ns, NSEC_PER_USEC); delay.unit = SPI_DELAY_UNIT_USECS; delay.value = clamp_val(us, 0, USHRT_MAX); } while (dw_spi_ctlr_busy(dws) && retry--) spi_delay_exec(&delay, NULL); if (retry < 0) { dev_err(&dws->master->dev, "Mem op hanged up\n"); return -EIO; } return 0; } static void dw_spi_stop_mem_op(struct dw_spi *dws, struct spi_device *spi) { spi_enable_chip(dws, 0); dw_spi_set_cs(spi, true); spi_enable_chip(dws, 1); } /* * The SPI memory operation implementation below is the best choice for the * devices, which are selected by the native chip-select lane. It's * specifically developed to workaround the problem with automatic chip-select * lane toggle when there is no data in the Tx FIFO buffer. Luckily the current * SPI-mem core calls exec_op() callback only if the GPIO-based CS is * unavailable. */ static int dw_spi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op) { struct dw_spi *dws = spi_controller_get_devdata(mem->spi->controller); struct dw_spi_cfg cfg; unsigned long flags; int ret; /* * Collect the outbound data into a single buffer to speed the * transmission up at least on the initial stage. */ ret = dw_spi_init_mem_buf(dws, op); if (ret) return ret; /* * DW SPI EEPROM-read mode is required only for the SPI memory Data-IN * operation. Transmit-only mode is suitable for the rest of them. */ cfg.dfs = 8; cfg.freq = clamp(mem->spi->max_speed_hz, 0U, dws->max_mem_freq); if (op->data.dir == SPI_MEM_DATA_IN) { cfg.tmode = SPI_TMOD_EPROMREAD; cfg.ndf = op->data.nbytes; } else { cfg.tmode = SPI_TMOD_TO; } spi_enable_chip(dws, 0); dw_spi_update_config(dws, mem->spi, &cfg); spi_mask_intr(dws, 0xff); spi_enable_chip(dws, 1); /* * DW APB SSI controller has very nasty peculiarities. First originally * (without any vendor-specific modifications) it doesn't provide a * direct way to set and clear the native chip-select signal. Instead * the controller asserts the CS lane if Tx FIFO isn't empty and a * transmission is going on, and automatically de-asserts it back to * the high level if the Tx FIFO doesn't have anything to be pushed * out. Due to that a multi-tasking or heavy IRQs activity might be * fatal, since the transfer procedure preemption may cause the Tx FIFO * getting empty and sudden CS de-assertion, which in the middle of the * transfer will most likely cause the data loss. Secondly the * EEPROM-read or Read-only DW SPI transfer modes imply the incoming * data being automatically pulled in into the Rx FIFO. So if the * driver software is late in fetching the data from the FIFO before * it's overflown, new incoming data will be lost. In order to make * sure the executed memory operations are CS-atomic and to prevent the * Rx FIFO overflow we have to disable the local interrupts so to block * any preemption during the subsequent IO operations. * * Note. At some circumstances disabling IRQs may not help to prevent * the problems described above. The CS de-assertion and Rx FIFO * overflow may still happen due to the relatively slow system bus or * CPU not working fast enough, so the write-then-read algo implemented * here just won't keep up with the SPI bus data transfer. Such * situation is highly platform specific and is supposed to be fixed by * manually restricting the SPI bus frequency using the * dws->max_mem_freq parameter. */ local_irq_save(flags); preempt_disable(); ret = dw_spi_write_then_read(dws, mem->spi); local_irq_restore(flags); preempt_enable(); /* * Wait for the operation being finished and check the controller * status only if there hasn't been any run-time error detected. In the * former case it's just pointless. In the later one to prevent an * additional error message printing since any hw error flag being set * would be due to an error detected on the data transfer. */ if (!ret) { ret = dw_spi_wait_mem_op_done(dws); if (!ret) ret = dw_spi_check_status(dws, true); } dw_spi_stop_mem_op(dws, mem->spi); dw_spi_free_mem_buf(dws); return ret; } /* * Initialize the default memory operations if a glue layer hasn't specified * custom ones. Direct mapping operations will be preserved anyway since DW SPI * controller doesn't have an embedded dirmap interface. Note the memory * operations implemented in this driver is the best choice only for the DW APB * SSI controller with standard native CS functionality. If a hardware vendor * has fixed the automatic CS assertion/de-assertion peculiarity, then it will * be safer to use the normal SPI-messages-based transfers implementation. */ static void dw_spi_init_mem_ops(struct dw_spi *dws) { if (!dws->mem_ops.exec_op && !(dws->caps & DW_SPI_CAP_CS_OVERRIDE) && !dws->set_cs) { dws->mem_ops.adjust_op_size = dw_spi_adjust_mem_op_size; dws->mem_ops.supports_op = dw_spi_supports_mem_op; dws->mem_ops.exec_op = dw_spi_exec_mem_op; if (!dws->max_mem_freq) dws->max_mem_freq = dws->max_freq; } } /* This may be called twice for each spi dev */ static int dw_spi_setup(struct spi_device *spi) { struct dw_spi *dws = spi_controller_get_devdata(spi->controller); struct chip_data *chip; /* Only alloc on first setup */ chip = spi_get_ctldata(spi); if (!chip) { struct dw_spi *dws = spi_controller_get_devdata(spi->controller); u32 rx_sample_dly_ns; chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); if (!chip) return -ENOMEM; spi_set_ctldata(spi, chip); /* Get specific / default rx-sample-delay */ if (device_property_read_u32(&spi->dev, "rx-sample-delay-ns", &rx_sample_dly_ns) != 0) /* Use default controller value */ rx_sample_dly_ns = dws->def_rx_sample_dly_ns; chip->rx_sample_dly = DIV_ROUND_CLOSEST(rx_sample_dly_ns, NSEC_PER_SEC / dws->max_freq); } /* * Update CR0 data each time the setup callback is invoked since * the device parameters could have been changed, for instance, by * the MMC SPI driver or something else. */ chip->cr0 = dw_spi_prepare_cr0(dws, spi); return 0; } static void dw_spi_cleanup(struct spi_device *spi) { struct chip_data *chip = spi_get_ctldata(spi); kfree(chip); spi_set_ctldata(spi, NULL); } /* Restart the controller, disable all interrupts, clean rx fifo */ static void spi_hw_init(struct device *dev, struct dw_spi *dws) { spi_reset_chip(dws); /* * Try to detect the FIFO depth if not set by interface driver, * the depth could be from 2 to 256 from HW spec */ if (!dws->fifo_len) { u32 fifo; for (fifo = 1; fifo < 256; fifo++) { dw_writel(dws, DW_SPI_TXFTLR, fifo); if (fifo != dw_readl(dws, DW_SPI_TXFTLR)) break; } dw_writel(dws, DW_SPI_TXFTLR, 0); dws->fifo_len = (fifo == 1) ? 0 : fifo; dev_dbg(dev, "Detected FIFO size: %u bytes\n", dws->fifo_len); } /* * Detect CTRLR0.DFS field size and offset by testing the lowest bits * writability. Note DWC SSI controller also has the extended DFS, but * with zero offset. */ if (!(dws->caps & DW_SPI_CAP_DWC_SSI)) { u32 cr0, tmp = dw_readl(dws, DW_SPI_CTRLR0); spi_enable_chip(dws, 0); dw_writel(dws, DW_SPI_CTRLR0, 0xffffffff); cr0 = dw_readl(dws, DW_SPI_CTRLR0); dw_writel(dws, DW_SPI_CTRLR0, tmp); spi_enable_chip(dws, 1); if (!(cr0 & SPI_DFS_MASK)) { dws->caps |= DW_SPI_CAP_DFS32; dws->dfs_offset = SPI_DFS32_OFFSET; dev_dbg(dev, "Detected 32-bits max data frame size\n"); } } else { dws->caps |= DW_SPI_CAP_DFS32; } /* enable HW fixup for explicit CS deselect for Amazon's alpine chip */ if (dws->caps & DW_SPI_CAP_CS_OVERRIDE) dw_writel(dws, DW_SPI_CS_OVERRIDE, 0xF); } int dw_spi_add_host(struct device *dev, struct dw_spi *dws) { struct spi_controller *master; int ret; if (!dws) return -EINVAL; master = spi_alloc_master(dev, 0); if (!master) return -ENOMEM; dws->master = master; dws->dma_addr = (dma_addr_t)(dws->paddr + DW_SPI_DR); spi_controller_set_devdata(master, dws); /* Basic HW init */ spi_hw_init(dev, dws); ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED, dev_name(dev), master); if (ret < 0 && ret != -ENOTCONN) { dev_err(dev, "can not get IRQ\n"); goto err_free_master; } dw_spi_init_mem_ops(dws); master->use_gpio_descriptors = true; master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP; if (dws->caps & DW_SPI_CAP_DFS32) master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32); else master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16); master->bus_num = dws->bus_num; master->num_chipselect = dws->num_cs; master->setup = dw_spi_setup; master->cleanup = dw_spi_cleanup; if (dws->set_cs) master->set_cs = dws->set_cs; else master->set_cs = dw_spi_set_cs; master->transfer_one = dw_spi_transfer_one; master->handle_err = dw_spi_handle_err; if (dws->mem_ops.exec_op) master->mem_ops = &dws->mem_ops; master->max_speed_hz = dws->max_freq; master->dev.of_node = dev->of_node; master->dev.fwnode = dev->fwnode; master->flags = SPI_MASTER_GPIO_SS; master->auto_runtime_pm = true; /* Get default rx sample delay */ device_property_read_u32(dev, "rx-sample-delay-ns", &dws->def_rx_sample_dly_ns); if (dws->dma_ops && dws->dma_ops->dma_init) { ret = dws->dma_ops->dma_init(dev, dws); if (ret) { dev_warn(dev, "DMA init failed\n"); } else { master->can_dma = dws->dma_ops->can_dma; master->flags |= SPI_CONTROLLER_MUST_TX; } } ret = spi_register_controller(master); if (ret) { dev_err(&master->dev, "problem registering spi master\n"); goto err_dma_exit; } dw_spi_debugfs_init(dws); return 0; err_dma_exit: if (dws->dma_ops && dws->dma_ops->dma_exit) dws->dma_ops->dma_exit(dws); spi_enable_chip(dws, 0); free_irq(dws->irq, master); err_free_master: spi_controller_put(master); return ret; } EXPORT_SYMBOL_GPL(dw_spi_add_host); void dw_spi_remove_host(struct dw_spi *dws) { dw_spi_debugfs_remove(dws); spi_unregister_controller(dws->master); if (dws->dma_ops && dws->dma_ops->dma_exit) dws->dma_ops->dma_exit(dws); spi_shutdown_chip(dws); free_irq(dws->irq, dws->master); } EXPORT_SYMBOL_GPL(dw_spi_remove_host); int dw_spi_suspend_host(struct dw_spi *dws) { int ret; ret = spi_controller_suspend(dws->master); if (ret) return ret; spi_shutdown_chip(dws); return 0; } EXPORT_SYMBOL_GPL(dw_spi_suspend_host); int dw_spi_resume_host(struct dw_spi *dws) { spi_hw_init(&dws->master->dev, dws); return spi_controller_resume(dws->master); } EXPORT_SYMBOL_GPL(dw_spi_resume_host); MODULE_AUTHOR("Feng Tang "); MODULE_DESCRIPTION("Driver for DesignWare SPI controller core"); MODULE_LICENSE("GPL v2");