diff options
Diffstat (limited to 'drivers/spi/spi-fsl-dspi.c')
| -rw-r--r-- | drivers/spi/spi-fsl-dspi.c | 557 |
1 files changed, 557 insertions, 0 deletions
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c new file mode 100644 index 0000000..6cd07d1 --- /dev/null +++ b/drivers/spi/spi-fsl-dspi.c @@ -0,0 +1,557 @@ +/* + * 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/kernel.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/errno.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> +#include <linux/pm_runtime.h> +#include <linux/of.h> +#include <linux/of_device.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_CTAR(x) (0x0c + (x * 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_PCSSCR(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_CTAR0_SLAVE 0x0c + +#define SPI_SR 0x2c +#define SPI_SR_EOQF 0x10000000 + +#define SPI_RSER 0x30 +#define SPI_RSER_EOQFE 0x10000000 + +#define SPI_PUSHR 0x34 +#define SPI_PUSHR_CONT (1 << 31) +#define SPI_PUSHR_CTAS(x) (((x) & 0x00000007) << 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 + +struct chip_data { + u32 mcr_val; + u32 ctar_val; + u16 void_write_data; +}; + +struct fsl_dspi { + struct spi_bitbang bitbang; + struct platform_device *pdev; + + void *base; + int irq; + struct clk *clk; + + struct spi_transfer *cur_transfer; + 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; + + wait_queue_head_t waitq; + u32 waitflags; +}; + +static inline int is_double_byte_mode(struct fsl_dspi *dspi) +{ + return ((readl(dspi->base + SPI_CTAR(dspi->cs)) & SPI_FRAME_BITS_MASK) + == SPI_FRAME_BITS(8)) ? 0 : 1; +} + +static void set_bit_mode(struct fsl_dspi *dspi, unsigned char bits) +{ + u32 temp; + + temp = readl(dspi->base + SPI_CTAR(dspi->cs)); + temp &= ~SPI_FRAME_BITS_MASK; + temp |= SPI_FRAME_BITS(bits); + writel(temp, dspi->base + SPI_CTAR(dspi->cs)); +} + +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 temp, i = 0, j = 0; + + temp = clkrate / 2 / speed_hz; + + for (i = 0; i < ARRAY_SIZE(pbr_tbl); i++) + for (j = 0; j < ARRAY_SIZE(brs); j++) { + if (pbr_tbl[i] * brs[j] >= temp) { + *pbr = i; + *br = j; + return; + } + } + + pr_warn("Can not find valid buad 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 int dspi_transfer_write(struct fsl_dspi *dspi) +{ + int tx_count = 0; + int tx_word; + u16 d16; + u8 d8; + u32 dspi_pushr = 0; + int first = 1; + + tx_word = is_double_byte_mode(dspi); + + /* If we are in word mode, but only have a single byte to transfer + * then 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; + set_bit_mode(dspi, 8); + tx_word = 0; + } + + while (dspi->len && (tx_count < DSPI_FIFO_SIZE)) { + if (tx_word) { + if (dspi->len == 1) + break; + + if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) { + d16 = *(u16 *)dspi->tx; + dspi->tx += 2; + } else { + d16 = dspi->void_write_data; + } + + dspi_pushr = SPI_PUSHR_TXDATA(d16) | + SPI_PUSHR_PCS(dspi->cs) | + SPI_PUSHR_CTAS(dspi->cs) | + SPI_PUSHR_CONT; + + dspi->len -= 2; + } else { + if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) { + + d8 = *(u8 *)dspi->tx; + dspi->tx++; + } else { + d8 = (u8)dspi->void_write_data; + } + + dspi_pushr = SPI_PUSHR_TXDATA(d8) | + SPI_PUSHR_PCS(dspi->cs) | + SPI_PUSHR_CTAS(dspi->cs) | + SPI_PUSHR_CONT; + + dspi->len--; + } + + if (dspi->len == 0 || tx_count == DSPI_FIFO_SIZE - 1) { + /* last transfer in the transfer */ + dspi_pushr |= SPI_PUSHR_EOQ; + } else if (tx_word && (dspi->len == 1)) + dspi_pushr |= SPI_PUSHR_EOQ; + + if (first) { + first = 0; + dspi_pushr |= SPI_PUSHR_CTCNT; /* clear counter */ + } + + writel(dspi_pushr, dspi->base + SPI_PUSHR); + tx_count++; + } + + return tx_count * (tx_word + 1); +} + +static int dspi_transfer_read(struct fsl_dspi *dspi) +{ + int rx_count = 0; + int rx_word = is_double_byte_mode(dspi); + u16 d; + while ((dspi->rx < dspi->rx_end) + && (rx_count < DSPI_FIFO_SIZE)) { + if (rx_word) { + if ((dspi->rx_end - dspi->rx) == 1) + break; + + d = SPI_POPR_RXDATA(readl(dspi->base + SPI_POPR)); + + if (!(dspi->dataflags & TRAN_STATE_RX_VOID)) + *(u16 *)dspi->rx = d; + dspi->rx += 2; + + } else { + d = SPI_POPR_RXDATA(readl(dspi->base + SPI_POPR)); + if (!(dspi->dataflags & TRAN_STATE_RX_VOID)) + *(u8 *)dspi->rx = d; + dspi->rx++; + } + rx_count++; + } + + return rx_count; +} + +static int dspi_txrx_transfer(struct spi_device *spi, struct spi_transfer *t) +{ + struct fsl_dspi *dspi = spi_master_get_devdata(spi->master); + dspi->cur_transfer = t; + dspi->cur_chip = spi_get_ctldata(spi); + dspi->cs = spi->chip_select; + dspi->void_write_data = dspi->cur_chip->void_write_data; + + dspi->dataflags = 0; + dspi->tx = (void *)t->tx_buf; + dspi->tx_end = dspi->tx + t->len; + dspi->rx = t->rx_buf; + dspi->rx_end = dspi->rx + t->len; + dspi->len = t->len; + + if (!dspi->rx) + dspi->dataflags |= TRAN_STATE_RX_VOID; + + if (!dspi->tx) + dspi->dataflags |= TRAN_STATE_TX_VOID; + + writel(dspi->cur_chip->mcr_val, dspi->base + SPI_MCR); + writel(dspi->cur_chip->ctar_val, dspi->base + SPI_CTAR(dspi->cs)); + writel(SPI_RSER_EOQFE, dspi->base + SPI_RSER); + + if (t->speed_hz) + writel(dspi->cur_chip->ctar_val, + dspi->base + SPI_CTAR(dspi->cs)); + + dspi_transfer_write(dspi); + + if (wait_event_interruptible(dspi->waitq, dspi->waitflags)) + dev_err(&dspi->pdev->dev, "wait transfer complete fail!\n"); + dspi->waitflags = 0; + + return t->len - dspi->len; +} + +static void dspi_chipselect(struct spi_device *spi, int value) +{ + struct fsl_dspi *dspi = spi_master_get_devdata(spi->master); + u32 pushr = readl(dspi->base + SPI_PUSHR); + + switch (value) { + case BITBANG_CS_ACTIVE: + pushr |= SPI_PUSHR_CONT; + case BITBANG_CS_INACTIVE: + pushr &= ~SPI_PUSHR_CONT; + } + + writel(pushr, dspi->base + SPI_PUSHR); +} + +static int dspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) +{ + struct chip_data *chip; + struct fsl_dspi *dspi = spi_master_get_devdata(spi->master); + unsigned char br = 0, pbr = 0, fmsz = 0; + + /* Only alloc on first setup */ + chip = spi_get_ctldata(spi); + if (chip == NULL) { + chip = kcalloc(1, sizeof(struct chip_data), GFP_KERNEL); + if (!chip) + return -ENOMEM; + } + + chip->mcr_val = SPI_MCR_MASTER | SPI_MCR_PCSIS | + SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF; + if ((spi->bits_per_word >= 4) && (spi->bits_per_word <= 16)) { + fmsz = spi->bits_per_word - 1; + } else { + pr_err("Invalid wordsize\n"); + kfree(chip); + return -ENODEV; + } + + chip->void_write_data = 0; + + hz_to_spi_baud(&pbr, &br, + spi->max_speed_hz, clk_get_rate(dspi->clk)); + + 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_PBR(pbr) + | SPI_CTAR_BR(br); + + spi_set_ctldata(spi, chip); + + return 0; +} + +static int dspi_setup(struct spi_device *spi) +{ + if (!spi->max_speed_hz) + return -EINVAL; + + if (!spi->bits_per_word) + spi->bits_per_word = 8; + + return dspi_setup_transfer(spi, NULL); +} + +static irqreturn_t dspi_interrupt(int irq, void *dev_id) +{ + struct fsl_dspi *dspi = (struct fsl_dspi *)dev_id; + + writel(SPI_SR_EOQF, dspi->base + SPI_SR); + + dspi_transfer_read(dspi); + + if (!dspi->len) { + if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM) + set_bit_mode(dspi, 16); + dspi->waitflags = 1; + wake_up_interruptible(&dspi->waitq); + } else { + dspi_transfer_write(dspi); + + return IRQ_HANDLED; + } + + return IRQ_HANDLED; +} + +static struct of_device_id fsl_dspi_dt_ids[] = { + { .compatible = "fsl,vf610-dspi", .data = NULL, }, + { /* 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); + + 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); + + clk_prepare_enable(dspi->clk); + spi_master_resume(master); + + return 0; +} +#endif /* CONFIG_PM_SLEEP */ + +static const struct dev_pm_ops dspi_pm = { + SET_SYSTEM_SLEEP_PM_OPS(dspi_suspend, dspi_resume) +}; + +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; + int ret = 0, cs_num, bus_num; + + master = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi)); + if (!master) + return -ENOMEM; + + dspi = spi_master_get_devdata(master); + dspi->pdev = pdev; + dspi->bitbang.master = spi_master_get(master); + dspi->bitbang.chipselect = dspi_chipselect; + dspi->bitbang.setup_transfer = dspi_setup_transfer; + dspi->bitbang.txrx_bufs = dspi_txrx_transfer; + dspi->bitbang.master->setup = dspi_setup; + dspi->bitbang.master->dev.of_node = pdev->dev.of_node; + + 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; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "can't get platform resource\n"); + ret = -EINVAL; + goto out_master_put; + } + + dspi->base = devm_ioremap_resource(&pdev->dev, res); + if (!dspi->base) { + ret = -EINVAL; + goto out_master_put; + } + + 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, dspi); + + ret = spi_bitbang_start(&dspi->bitbang); + if (ret != 0) { + dev_err(&pdev->dev, "Problem registering DSPI master\n"); + goto out_clk_put; + } + + pr_info(KERN_INFO "Freescale DSPI master initialized\n"); + return ret; + +out_clk_put: + clk_disable_unprepare(dspi->clk); +out_master_put: + spi_master_put(master); + platform_set_drvdata(pdev, NULL); + + return ret; +} + +static int dspi_remove(struct platform_device *pdev) +{ + struct fsl_dspi *dspi = platform_get_drvdata(pdev); + + /* Disconnect from the SPI framework */ + spi_bitbang_stop(&dspi->bitbang); + spi_master_put(dspi->bitbang.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 v2"); +MODULE_ALIAS("platform:" DRIVER_NAME); |