/* * drivers/spi/spi-fsl-dspi.c * * Copyright 2013 Freescale Semiconductor, Inc. * * Freescale DSPI driver * This file contains a driver for the Freescale DSPI * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * */ #include <linux/clk.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/errno.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/math64.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/pinctrl/consumer.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/regmap.h> #include <linux/sched.h> #include <linux/spi/spi.h> #include <linux/spi/spi_bitbang.h> #include <linux/time.h> #define DRIVER_NAME "fsl-dspi" #define TRAN_STATE_RX_VOID 0x01 #define TRAN_STATE_TX_VOID 0x02 #define TRAN_STATE_WORD_ODD_NUM 0x04 #define DSPI_FIFO_SIZE 4 #define SPI_MCR 0x00 #define SPI_MCR_MASTER (1 << 31) #define SPI_MCR_PCSIS (0x3F << 16) #define SPI_MCR_CLR_TXF (1 << 11) #define SPI_MCR_CLR_RXF (1 << 10) #define SPI_TCR 0x08 #define SPI_TCR_GET_TCNT(x) (((x) & 0xffff0000) >> 16) #define SPI_CTAR(x) (0x0c + (((x) & 0x3) * 4)) #define SPI_CTAR_FMSZ(x) (((x) & 0x0000000f) << 27) #define SPI_CTAR_CPOL(x) ((x) << 26) #define SPI_CTAR_CPHA(x) ((x) << 25) #define SPI_CTAR_LSBFE(x) ((x) << 24) #define SPI_CTAR_PCSSCK(x) (((x) & 0x00000003) << 22) #define SPI_CTAR_PASC(x) (((x) & 0x00000003) << 20) #define SPI_CTAR_PDT(x) (((x) & 0x00000003) << 18) #define SPI_CTAR_PBR(x) (((x) & 0x00000003) << 16) #define SPI_CTAR_CSSCK(x) (((x) & 0x0000000f) << 12) #define SPI_CTAR_ASC(x) (((x) & 0x0000000f) << 8) #define SPI_CTAR_DT(x) (((x) & 0x0000000f) << 4) #define SPI_CTAR_BR(x) ((x) & 0x0000000f) #define SPI_CTAR_SCALE_BITS 0xf #define SPI_CTAR0_SLAVE 0x0c #define SPI_SR 0x2c #define SPI_SR_EOQF 0x10000000 #define SPI_SR_TCFQF 0x80000000 #define SPI_RSER 0x30 #define SPI_RSER_EOQFE 0x10000000 #define SPI_RSER_TCFQE 0x80000000 #define SPI_PUSHR 0x34 #define SPI_PUSHR_CONT (1 << 31) #define SPI_PUSHR_CTAS(x) (((x) & 0x00000003) << 28) #define SPI_PUSHR_EOQ (1 << 27) #define SPI_PUSHR_CTCNT (1 << 26) #define SPI_PUSHR_PCS(x) (((1 << x) & 0x0000003f) << 16) #define SPI_PUSHR_TXDATA(x) ((x) & 0x0000ffff) #define SPI_PUSHR_SLAVE 0x34 #define SPI_POPR 0x38 #define SPI_POPR_RXDATA(x) ((x) & 0x0000ffff) #define SPI_TXFR0 0x3c #define SPI_TXFR1 0x40 #define SPI_TXFR2 0x44 #define SPI_TXFR3 0x48 #define SPI_RXFR0 0x7c #define SPI_RXFR1 0x80 #define SPI_RXFR2 0x84 #define SPI_RXFR3 0x88 #define SPI_FRAME_BITS(bits) SPI_CTAR_FMSZ((bits) - 1) #define SPI_FRAME_BITS_MASK SPI_CTAR_FMSZ(0xf) #define SPI_FRAME_BITS_16 SPI_CTAR_FMSZ(0xf) #define SPI_FRAME_BITS_8 SPI_CTAR_FMSZ(0x7) #define SPI_CS_INIT 0x01 #define SPI_CS_ASSERT 0x02 #define SPI_CS_DROP 0x04 #define SPI_TCR_TCNT_MAX 0x10000 struct chip_data { u32 mcr_val; u32 ctar_val; u16 void_write_data; }; enum dspi_trans_mode { DSPI_EOQ_MODE = 0, DSPI_TCFQ_MODE, }; struct fsl_dspi_devtype_data { enum dspi_trans_mode trans_mode; }; static const struct fsl_dspi_devtype_data vf610_data = { .trans_mode = DSPI_EOQ_MODE, }; static const struct fsl_dspi_devtype_data ls1021a_v1_data = { .trans_mode = DSPI_TCFQ_MODE, }; static const struct fsl_dspi_devtype_data ls2085a_data = { .trans_mode = DSPI_TCFQ_MODE, }; struct fsl_dspi { struct spi_master *master; struct platform_device *pdev; struct regmap *regmap; int irq; struct clk *clk; struct spi_transfer *cur_transfer; struct spi_message *cur_msg; struct chip_data *cur_chip; size_t len; void *tx; void *tx_end; void *rx; void *rx_end; char dataflags; u8 cs; u16 void_write_data; u32 cs_change; struct fsl_dspi_devtype_data *devtype_data; wait_queue_head_t waitq; u32 waitflags; u32 spi_tcnt; }; static inline int is_double_byte_mode(struct fsl_dspi *dspi) { unsigned int val; regmap_read(dspi->regmap, SPI_CTAR(0), &val); return ((val & SPI_FRAME_BITS_MASK) == SPI_FRAME_BITS(8)) ? 0 : 1; } static void hz_to_spi_baud(char *pbr, char *br, int speed_hz, unsigned long clkrate) { /* Valid baud rate pre-scaler values */ int pbr_tbl[4] = {2, 3, 5, 7}; int brs[16] = { 2, 4, 6, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768 }; int scale_needed, scale, minscale = INT_MAX; int i, j; scale_needed = clkrate / speed_hz; if (clkrate % speed_hz) scale_needed++; for (i = 0; i < ARRAY_SIZE(brs); i++) for (j = 0; j < ARRAY_SIZE(pbr_tbl); j++) { scale = brs[i] * pbr_tbl[j]; if (scale >= scale_needed) { if (scale < minscale) { minscale = scale; *br = i; *pbr = j; } break; } } if (minscale == INT_MAX) { pr_warn("Can not find valid baud rate,speed_hz is %d,clkrate is %ld, we use the max prescaler value.\n", speed_hz, clkrate); *pbr = ARRAY_SIZE(pbr_tbl) - 1; *br = ARRAY_SIZE(brs) - 1; } } static void ns_delay_scale(char *psc, char *sc, int delay_ns, unsigned long clkrate) { int pscale_tbl[4] = {1, 3, 5, 7}; int scale_needed, scale, minscale = INT_MAX; int i, j; u32 remainder; scale_needed = div_u64_rem((u64)delay_ns * clkrate, NSEC_PER_SEC, &remainder); if (remainder) scale_needed++; for (i = 0; i < ARRAY_SIZE(pscale_tbl); i++) for (j = 0; j <= SPI_CTAR_SCALE_BITS; j++) { scale = pscale_tbl[i] * (2 << j); if (scale >= scale_needed) { if (scale < minscale) { minscale = scale; *psc = i; *sc = j; } break; } } if (minscale == INT_MAX) { pr_warn("Cannot find correct scale values for %dns delay at clkrate %ld, using max prescaler value", delay_ns, clkrate); *psc = ARRAY_SIZE(pscale_tbl) - 1; *sc = SPI_CTAR_SCALE_BITS; } } static u32 dspi_data_to_pushr(struct fsl_dspi *dspi, int tx_word) { u16 d16; if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) d16 = tx_word ? *(u16 *)dspi->tx : *(u8 *)dspi->tx; else d16 = dspi->void_write_data; dspi->tx += tx_word + 1; dspi->len -= tx_word + 1; return SPI_PUSHR_TXDATA(d16) | SPI_PUSHR_PCS(dspi->cs) | SPI_PUSHR_CTAS(0) | SPI_PUSHR_CONT; } static void dspi_data_from_popr(struct fsl_dspi *dspi, int rx_word) { u16 d; unsigned int val; regmap_read(dspi->regmap, SPI_POPR, &val); d = SPI_POPR_RXDATA(val); if (!(dspi->dataflags & TRAN_STATE_RX_VOID)) rx_word ? (*(u16 *)dspi->rx = d) : (*(u8 *)dspi->rx = d); dspi->rx += rx_word + 1; } static int dspi_eoq_write(struct fsl_dspi *dspi) { int tx_count = 0; int tx_word; u32 dspi_pushr = 0; tx_word = is_double_byte_mode(dspi); while (dspi->len && (tx_count < DSPI_FIFO_SIZE)) { /* If we are in word mode, only have a single byte to transfer * switch to byte mode temporarily. Will switch back at the * end of the transfer. */ if (tx_word && (dspi->len == 1)) { dspi->dataflags |= TRAN_STATE_WORD_ODD_NUM; regmap_update_bits(dspi->regmap, SPI_CTAR(0), SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(8)); tx_word = 0; } dspi_pushr = dspi_data_to_pushr(dspi, tx_word); if (dspi->len == 0 || tx_count == DSPI_FIFO_SIZE - 1) { /* last transfer in the transfer */ dspi_pushr |= SPI_PUSHR_EOQ; if ((dspi->cs_change) && (!dspi->len)) dspi_pushr &= ~SPI_PUSHR_CONT; } else if (tx_word && (dspi->len == 1)) dspi_pushr |= SPI_PUSHR_EOQ; regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr); tx_count++; } return tx_count * (tx_word + 1); } static int dspi_eoq_read(struct fsl_dspi *dspi) { int rx_count = 0; int rx_word = is_double_byte_mode(dspi); while ((dspi->rx < dspi->rx_end) && (rx_count < DSPI_FIFO_SIZE)) { if (rx_word && (dspi->rx_end - dspi->rx) == 1) rx_word = 0; dspi_data_from_popr(dspi, rx_word); rx_count++; } return rx_count; } static int dspi_tcfq_write(struct fsl_dspi *dspi) { int tx_word; u32 dspi_pushr = 0; tx_word = is_double_byte_mode(dspi); if (tx_word && (dspi->len == 1)) { dspi->dataflags |= TRAN_STATE_WORD_ODD_NUM; regmap_update_bits(dspi->regmap, SPI_CTAR(0), SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(8)); tx_word = 0; } dspi_pushr = dspi_data_to_pushr(dspi, tx_word); if ((dspi->cs_change) && (!dspi->len)) dspi_pushr &= ~SPI_PUSHR_CONT; regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr); return tx_word + 1; } static void dspi_tcfq_read(struct fsl_dspi *dspi) { int rx_word = is_double_byte_mode(dspi); if (rx_word && (dspi->rx_end - dspi->rx) == 1) rx_word = 0; dspi_data_from_popr(dspi, rx_word); } static int dspi_transfer_one_message(struct spi_master *master, struct spi_message *message) { struct fsl_dspi *dspi = spi_master_get_devdata(master); struct spi_device *spi = message->spi; struct spi_transfer *transfer; int status = 0; enum dspi_trans_mode trans_mode; u32 spi_tcr; regmap_read(dspi->regmap, SPI_TCR, &spi_tcr); dspi->spi_tcnt = SPI_TCR_GET_TCNT(spi_tcr); message->actual_length = 0; list_for_each_entry(transfer, &message->transfers, transfer_list) { dspi->cur_transfer = transfer; dspi->cur_msg = message; dspi->cur_chip = spi_get_ctldata(spi); dspi->cs = spi->chip_select; dspi->cs_change = 0; if (dspi->cur_transfer->transfer_list.next == &dspi->cur_msg->transfers) dspi->cs_change = 1; dspi->void_write_data = dspi->cur_chip->void_write_data; dspi->dataflags = 0; dspi->tx = (void *)transfer->tx_buf; dspi->tx_end = dspi->tx + transfer->len; dspi->rx = transfer->rx_buf; dspi->rx_end = dspi->rx + transfer->len; dspi->len = transfer->len; if (!dspi->rx) dspi->dataflags |= TRAN_STATE_RX_VOID; if (!dspi->tx) dspi->dataflags |= TRAN_STATE_TX_VOID; regmap_write(dspi->regmap, SPI_MCR, dspi->cur_chip->mcr_val); regmap_update_bits(dspi->regmap, SPI_MCR, SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF, SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF); regmap_write(dspi->regmap, SPI_CTAR(0), dspi->cur_chip->ctar_val); trans_mode = dspi->devtype_data->trans_mode; switch (trans_mode) { case DSPI_EOQ_MODE: regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE); dspi_eoq_write(dspi); break; case DSPI_TCFQ_MODE: regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_TCFQE); dspi_tcfq_write(dspi); break; default: dev_err(&dspi->pdev->dev, "unsupported trans_mode %u\n", trans_mode); status = -EINVAL; goto out; } if (wait_event_interruptible(dspi->waitq, dspi->waitflags)) dev_err(&dspi->pdev->dev, "wait transfer complete fail!\n"); dspi->waitflags = 0; if (transfer->delay_usecs) udelay(transfer->delay_usecs); } out: message->status = status; spi_finalize_current_message(master); return status; } static int dspi_setup(struct spi_device *spi) { struct chip_data *chip; struct fsl_dspi *dspi = spi_master_get_devdata(spi->master); u32 cs_sck_delay = 0, sck_cs_delay = 0; unsigned char br = 0, pbr = 0, pcssck = 0, cssck = 0; unsigned char pasc = 0, asc = 0, fmsz = 0; unsigned long clkrate; if ((spi->bits_per_word >= 4) && (spi->bits_per_word <= 16)) { fmsz = spi->bits_per_word - 1; } else { pr_err("Invalid wordsize\n"); return -ENODEV; } /* Only alloc on first setup */ chip = spi_get_ctldata(spi); if (chip == NULL) { chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); if (!chip) return -ENOMEM; } of_property_read_u32(spi->dev.of_node, "fsl,spi-cs-sck-delay", &cs_sck_delay); of_property_read_u32(spi->dev.of_node, "fsl,spi-sck-cs-delay", &sck_cs_delay); chip->mcr_val = SPI_MCR_MASTER | SPI_MCR_PCSIS | SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF; chip->void_write_data = 0; clkrate = clk_get_rate(dspi->clk); hz_to_spi_baud(&pbr, &br, spi->max_speed_hz, clkrate); /* Set PCS to SCK delay scale values */ ns_delay_scale(&pcssck, &cssck, cs_sck_delay, clkrate); /* Set After SCK delay scale values */ ns_delay_scale(&pasc, &asc, sck_cs_delay, clkrate); chip->ctar_val = SPI_CTAR_FMSZ(fmsz) | SPI_CTAR_CPOL(spi->mode & SPI_CPOL ? 1 : 0) | SPI_CTAR_CPHA(spi->mode & SPI_CPHA ? 1 : 0) | SPI_CTAR_LSBFE(spi->mode & SPI_LSB_FIRST ? 1 : 0) | SPI_CTAR_PCSSCK(pcssck) | SPI_CTAR_CSSCK(cssck) | SPI_CTAR_PASC(pasc) | SPI_CTAR_ASC(asc) | SPI_CTAR_PBR(pbr) | SPI_CTAR_BR(br); spi_set_ctldata(spi, chip); return 0; } static void dspi_cleanup(struct spi_device *spi) { struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi); dev_dbg(&spi->dev, "spi_device %u.%u cleanup\n", spi->master->bus_num, spi->chip_select); kfree(chip); } static irqreturn_t dspi_interrupt(int irq, void *dev_id) { struct fsl_dspi *dspi = (struct fsl_dspi *)dev_id; struct spi_message *msg = dspi->cur_msg; enum dspi_trans_mode trans_mode; u32 spi_sr, spi_tcr; u32 spi_tcnt, tcnt_diff; int tx_word; regmap_read(dspi->regmap, SPI_SR, &spi_sr); regmap_write(dspi->regmap, SPI_SR, spi_sr); if (spi_sr & (SPI_SR_EOQF | SPI_SR_TCFQF)) { tx_word = is_double_byte_mode(dspi); regmap_read(dspi->regmap, SPI_TCR, &spi_tcr); spi_tcnt = SPI_TCR_GET_TCNT(spi_tcr); /* * The width of SPI Transfer Counter in SPI_TCR is 16bits, * so the max couner is 65535. When the counter reach 65535, * it will wrap around, counter reset to zero. * spi_tcnt my be less than dspi->spi_tcnt, it means the * counter already wrapped around. * SPI Transfer Counter is a counter of transmitted frames. * The size of frame maybe two bytes. */ tcnt_diff = ((spi_tcnt + SPI_TCR_TCNT_MAX) - dspi->spi_tcnt) % SPI_TCR_TCNT_MAX; tcnt_diff *= (tx_word + 1); if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM) tcnt_diff--; msg->actual_length += tcnt_diff; dspi->spi_tcnt = spi_tcnt; trans_mode = dspi->devtype_data->trans_mode; switch (trans_mode) { case DSPI_EOQ_MODE: dspi_eoq_read(dspi); break; case DSPI_TCFQ_MODE: dspi_tcfq_read(dspi); break; default: dev_err(&dspi->pdev->dev, "unsupported trans_mode %u\n", trans_mode); return IRQ_HANDLED; } if (!dspi->len) { if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM) { regmap_update_bits(dspi->regmap, SPI_CTAR(0), SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(16)); dspi->dataflags &= ~TRAN_STATE_WORD_ODD_NUM; } dspi->waitflags = 1; wake_up_interruptible(&dspi->waitq); } else { switch (trans_mode) { case DSPI_EOQ_MODE: dspi_eoq_write(dspi); break; case DSPI_TCFQ_MODE: dspi_tcfq_write(dspi); break; default: dev_err(&dspi->pdev->dev, "unsupported trans_mode %u\n", trans_mode); } } } return IRQ_HANDLED; } static const struct of_device_id fsl_dspi_dt_ids[] = { { .compatible = "fsl,vf610-dspi", .data = (void *)&vf610_data, }, { .compatible = "fsl,ls1021a-v1.0-dspi", .data = (void *)&ls1021a_v1_data, }, { .compatible = "fsl,ls2085a-dspi", .data = (void *)&ls2085a_data, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, fsl_dspi_dt_ids); #ifdef CONFIG_PM_SLEEP static int dspi_suspend(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct fsl_dspi *dspi = spi_master_get_devdata(master); spi_master_suspend(master); clk_disable_unprepare(dspi->clk); pinctrl_pm_select_sleep_state(dev); return 0; } static int dspi_resume(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct fsl_dspi *dspi = spi_master_get_devdata(master); pinctrl_pm_select_default_state(dev); clk_prepare_enable(dspi->clk); spi_master_resume(master); return 0; } #endif /* CONFIG_PM_SLEEP */ static SIMPLE_DEV_PM_OPS(dspi_pm, dspi_suspend, dspi_resume); static const struct regmap_config dspi_regmap_config = { .reg_bits = 32, .val_bits = 32, .reg_stride = 4, .max_register = 0x88, }; static int dspi_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct spi_master *master; struct fsl_dspi *dspi; struct resource *res; void __iomem *base; int ret = 0, cs_num, bus_num; const struct of_device_id *of_id = of_match_device(fsl_dspi_dt_ids, &pdev->dev); master = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi)); if (!master) return -ENOMEM; dspi = spi_master_get_devdata(master); dspi->pdev = pdev; dspi->master = master; master->transfer = NULL; master->setup = dspi_setup; master->transfer_one_message = dspi_transfer_one_message; master->dev.of_node = pdev->dev.of_node; master->cleanup = dspi_cleanup; master->mode_bits = SPI_CPOL | SPI_CPHA; master->bits_per_word_mask = SPI_BPW_MASK(4) | SPI_BPW_MASK(8) | SPI_BPW_MASK(16); ret = of_property_read_u32(np, "spi-num-chipselects", &cs_num); if (ret < 0) { dev_err(&pdev->dev, "can't get spi-num-chipselects\n"); goto out_master_put; } master->num_chipselect = cs_num; ret = of_property_read_u32(np, "bus-num", &bus_num); if (ret < 0) { dev_err(&pdev->dev, "can't get bus-num\n"); goto out_master_put; } master->bus_num = bus_num; dspi->devtype_data = (struct fsl_dspi_devtype_data *)of_id->data; if (!dspi->devtype_data) { dev_err(&pdev->dev, "can't get devtype_data\n"); ret = -EFAULT; goto out_master_put; } res = platform_get_resource(pdev, IORESOURCE_MEM, 0); base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(base)) { ret = PTR_ERR(base); goto out_master_put; } dspi->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base, &dspi_regmap_config); if (IS_ERR(dspi->regmap)) { dev_err(&pdev->dev, "failed to init regmap: %ld\n", PTR_ERR(dspi->regmap)); return PTR_ERR(dspi->regmap); } dspi->irq = platform_get_irq(pdev, 0); if (dspi->irq < 0) { dev_err(&pdev->dev, "can't get platform irq\n"); ret = dspi->irq; goto out_master_put; } ret = devm_request_irq(&pdev->dev, dspi->irq, dspi_interrupt, 0, pdev->name, dspi); if (ret < 0) { dev_err(&pdev->dev, "Unable to attach DSPI interrupt\n"); goto out_master_put; } dspi->clk = devm_clk_get(&pdev->dev, "dspi"); if (IS_ERR(dspi->clk)) { ret = PTR_ERR(dspi->clk); dev_err(&pdev->dev, "unable to get clock\n"); goto out_master_put; } clk_prepare_enable(dspi->clk); init_waitqueue_head(&dspi->waitq); platform_set_drvdata(pdev, master); ret = spi_register_master(master); if (ret != 0) { dev_err(&pdev->dev, "Problem registering DSPI master\n"); goto out_clk_put; } return ret; out_clk_put: clk_disable_unprepare(dspi->clk); out_master_put: spi_master_put(master); return ret; } static int dspi_remove(struct platform_device *pdev) { struct spi_master *master = platform_get_drvdata(pdev); struct fsl_dspi *dspi = spi_master_get_devdata(master); /* Disconnect from the SPI framework */ clk_disable_unprepare(dspi->clk); spi_unregister_master(dspi->master); spi_master_put(dspi->master); return 0; } static struct platform_driver fsl_dspi_driver = { .driver.name = DRIVER_NAME, .driver.of_match_table = fsl_dspi_dt_ids, .driver.owner = THIS_MODULE, .driver.pm = &dspi_pm, .probe = dspi_probe, .remove = dspi_remove, }; module_platform_driver(fsl_dspi_driver); MODULE_DESCRIPTION("Freescale DSPI Controller Driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:" DRIVER_NAME);