- 根目录:
- drivers
- spi
- spi-fsl-dspi.c
/*
* 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 __iomem *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 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 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;
break;
case BITBANG_CS_INACTIVE:
pushr &= ~SPI_PUSHR_CONT;
break;
}
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;
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 = 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);
dspi->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(dspi->base)) {
ret = PTR_ERR(dspi->base);
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, master);
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);
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 */
spi_bitbang_stop(&dspi->bitbang);
clk_disable_unprepare(dspi->clk);
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");
MODULE_ALIAS("platform:" DRIVER_NAME);