u-boot-brain/drivers/spi/spi-sifive.c

481 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2018 SiFive, Inc.
* Copyright 2019 Bhargav Shah <bhargavshah1988@gmail.com>
*
* SiFive SPI controller driver (master mode only)
*/
#include <common.h>
#include <dm.h>
#include <dm/device_compat.h>
#include <malloc.h>
#include <spi.h>
#include <spi-mem.h>
#include <wait_bit.h>
#include <asm/io.h>
#include <linux/bitops.h>
#include <linux/log2.h>
#include <clk.h>
#define SIFIVE_SPI_MAX_CS 32
#define SIFIVE_SPI_DEFAULT_DEPTH 8
#define SIFIVE_SPI_DEFAULT_BITS 8
/* register offsets */
#define SIFIVE_SPI_REG_SCKDIV 0x00 /* Serial clock divisor */
#define SIFIVE_SPI_REG_SCKMODE 0x04 /* Serial clock mode */
#define SIFIVE_SPI_REG_CSID 0x10 /* Chip select ID */
#define SIFIVE_SPI_REG_CSDEF 0x14 /* Chip select default */
#define SIFIVE_SPI_REG_CSMODE 0x18 /* Chip select mode */
#define SIFIVE_SPI_REG_DELAY0 0x28 /* Delay control 0 */
#define SIFIVE_SPI_REG_DELAY1 0x2c /* Delay control 1 */
#define SIFIVE_SPI_REG_FMT 0x40 /* Frame format */
#define SIFIVE_SPI_REG_TXDATA 0x48 /* Tx FIFO data */
#define SIFIVE_SPI_REG_RXDATA 0x4c /* Rx FIFO data */
#define SIFIVE_SPI_REG_TXMARK 0x50 /* Tx FIFO watermark */
#define SIFIVE_SPI_REG_RXMARK 0x54 /* Rx FIFO watermark */
#define SIFIVE_SPI_REG_FCTRL 0x60 /* SPI flash interface control */
#define SIFIVE_SPI_REG_FFMT 0x64 /* SPI flash instruction format */
#define SIFIVE_SPI_REG_IE 0x70 /* Interrupt Enable Register */
#define SIFIVE_SPI_REG_IP 0x74 /* Interrupt Pendings Register */
/* sckdiv bits */
#define SIFIVE_SPI_SCKDIV_DIV_MASK 0xfffU
/* sckmode bits */
#define SIFIVE_SPI_SCKMODE_PHA BIT(0)
#define SIFIVE_SPI_SCKMODE_POL BIT(1)
#define SIFIVE_SPI_SCKMODE_MODE_MASK (SIFIVE_SPI_SCKMODE_PHA | \
SIFIVE_SPI_SCKMODE_POL)
/* csmode bits */
#define SIFIVE_SPI_CSMODE_MODE_AUTO 0U
#define SIFIVE_SPI_CSMODE_MODE_HOLD 2U
#define SIFIVE_SPI_CSMODE_MODE_OFF 3U
/* delay0 bits */
#define SIFIVE_SPI_DELAY0_CSSCK(x) ((u32)(x))
#define SIFIVE_SPI_DELAY0_CSSCK_MASK 0xffU
#define SIFIVE_SPI_DELAY0_SCKCS(x) ((u32)(x) << 16)
#define SIFIVE_SPI_DELAY0_SCKCS_MASK (0xffU << 16)
/* delay1 bits */
#define SIFIVE_SPI_DELAY1_INTERCS(x) ((u32)(x))
#define SIFIVE_SPI_DELAY1_INTERCS_MASK 0xffU
#define SIFIVE_SPI_DELAY1_INTERXFR(x) ((u32)(x) << 16)
#define SIFIVE_SPI_DELAY1_INTERXFR_MASK (0xffU << 16)
/* fmt bits */
#define SIFIVE_SPI_FMT_PROTO_SINGLE 0U
#define SIFIVE_SPI_FMT_PROTO_DUAL 1U
#define SIFIVE_SPI_FMT_PROTO_QUAD 2U
#define SIFIVE_SPI_FMT_PROTO_MASK 3U
#define SIFIVE_SPI_FMT_ENDIAN BIT(2)
#define SIFIVE_SPI_FMT_DIR BIT(3)
#define SIFIVE_SPI_FMT_LEN(x) ((u32)(x) << 16)
#define SIFIVE_SPI_FMT_LEN_MASK (0xfU << 16)
/* txdata bits */
#define SIFIVE_SPI_TXDATA_DATA_MASK 0xffU
#define SIFIVE_SPI_TXDATA_FULL BIT(31)
/* rxdata bits */
#define SIFIVE_SPI_RXDATA_DATA_MASK 0xffU
#define SIFIVE_SPI_RXDATA_EMPTY BIT(31)
/* ie and ip bits */
#define SIFIVE_SPI_IP_TXWM BIT(0)
#define SIFIVE_SPI_IP_RXWM BIT(1)
/* format protocol */
#define SIFIVE_SPI_PROTO_QUAD 4 /* 4 lines I/O protocol transfer */
#define SIFIVE_SPI_PROTO_DUAL 2 /* 2 lines I/O protocol transfer */
#define SIFIVE_SPI_PROTO_SINGLE 1 /* 1 line I/O protocol transfer */
struct sifive_spi {
void *regs; /* base address of the registers */
u32 fifo_depth;
u32 bits_per_word;
u32 cs_inactive; /* Level of the CS pins when inactive*/
u32 freq;
u32 num_cs;
u8 fmt_proto;
};
static void sifive_spi_prep_device(struct sifive_spi *spi,
struct dm_spi_slave_plat *slave_plat)
{
/* Update the chip select polarity */
if (slave_plat->mode & SPI_CS_HIGH)
spi->cs_inactive &= ~BIT(slave_plat->cs);
else
spi->cs_inactive |= BIT(slave_plat->cs);
writel(spi->cs_inactive, spi->regs + SIFIVE_SPI_REG_CSDEF);
/* Select the correct device */
writel(slave_plat->cs, spi->regs + SIFIVE_SPI_REG_CSID);
}
static int sifive_spi_set_cs(struct sifive_spi *spi,
struct dm_spi_slave_plat *slave_plat)
{
u32 cs_mode = SIFIVE_SPI_CSMODE_MODE_HOLD;
if (slave_plat->mode & SPI_CS_HIGH)
cs_mode = SIFIVE_SPI_CSMODE_MODE_AUTO;
writel(cs_mode, spi->regs + SIFIVE_SPI_REG_CSMODE);
return 0;
}
static void sifive_spi_clear_cs(struct sifive_spi *spi)
{
writel(SIFIVE_SPI_CSMODE_MODE_AUTO, spi->regs + SIFIVE_SPI_REG_CSMODE);
}
static void sifive_spi_prep_transfer(struct sifive_spi *spi,
struct dm_spi_slave_plat *slave_plat,
u8 *rx_ptr)
{
u32 cr;
/* Modify the SPI protocol mode */
cr = readl(spi->regs + SIFIVE_SPI_REG_FMT);
/* Bits per word ? */
cr &= ~SIFIVE_SPI_FMT_LEN_MASK;
cr |= SIFIVE_SPI_FMT_LEN(spi->bits_per_word);
/* LSB first? */
cr &= ~SIFIVE_SPI_FMT_ENDIAN;
if (slave_plat->mode & SPI_LSB_FIRST)
cr |= SIFIVE_SPI_FMT_ENDIAN;
/* Number of wires ? */
cr &= ~SIFIVE_SPI_FMT_PROTO_MASK;
switch (spi->fmt_proto) {
case SIFIVE_SPI_PROTO_QUAD:
cr |= SIFIVE_SPI_FMT_PROTO_QUAD;
break;
case SIFIVE_SPI_PROTO_DUAL:
cr |= SIFIVE_SPI_FMT_PROTO_DUAL;
break;
default:
cr |= SIFIVE_SPI_FMT_PROTO_SINGLE;
break;
}
/* SPI direction in/out ? */
cr &= ~SIFIVE_SPI_FMT_DIR;
if (!rx_ptr)
cr |= SIFIVE_SPI_FMT_DIR;
writel(cr, spi->regs + SIFIVE_SPI_REG_FMT);
}
static void sifive_spi_rx(struct sifive_spi *spi, u8 *rx_ptr)
{
u32 data;
do {
data = readl(spi->regs + SIFIVE_SPI_REG_RXDATA);
} while (data & SIFIVE_SPI_RXDATA_EMPTY);
if (rx_ptr)
*rx_ptr = data & SIFIVE_SPI_RXDATA_DATA_MASK;
}
static void sifive_spi_tx(struct sifive_spi *spi, const u8 *tx_ptr)
{
u32 data;
u8 tx_data = (tx_ptr) ? *tx_ptr & SIFIVE_SPI_TXDATA_DATA_MASK :
SIFIVE_SPI_TXDATA_DATA_MASK;
do {
data = readl(spi->regs + SIFIVE_SPI_REG_TXDATA);
} while (data & SIFIVE_SPI_TXDATA_FULL);
writel(tx_data, spi->regs + SIFIVE_SPI_REG_TXDATA);
}
static int sifive_spi_wait(struct sifive_spi *spi, u32 bit)
{
return wait_for_bit_le32(spi->regs + SIFIVE_SPI_REG_IP,
bit, true, 100, false);
}
static int sifive_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = dev->parent;
struct sifive_spi *spi = dev_get_priv(bus);
struct dm_spi_slave_plat *slave_plat = dev_get_parent_plat(dev);
const u8 *tx_ptr = dout;
u8 *rx_ptr = din;
u32 remaining_len;
int ret;
if (flags & SPI_XFER_BEGIN) {
sifive_spi_prep_device(spi, slave_plat);
ret = sifive_spi_set_cs(spi, slave_plat);
if (ret)
return ret;
}
sifive_spi_prep_transfer(spi, slave_plat, rx_ptr);
remaining_len = bitlen / 8;
while (remaining_len) {
unsigned int n_words = min(remaining_len, spi->fifo_depth);
unsigned int tx_words, rx_words;
/* Enqueue n_words for transmission */
for (tx_words = 0; tx_words < n_words; tx_words++) {
if (!tx_ptr)
sifive_spi_tx(spi, NULL);
else
sifive_spi_tx(spi, tx_ptr++);
}
if (rx_ptr) {
/* Wait for transmission + reception to complete */
writel(n_words - 1, spi->regs + SIFIVE_SPI_REG_RXMARK);
ret = sifive_spi_wait(spi, SIFIVE_SPI_IP_RXWM);
if (ret)
return ret;
/* Read out all the data from the RX FIFO */
for (rx_words = 0; rx_words < n_words; rx_words++)
sifive_spi_rx(spi, rx_ptr++);
} else {
/* Wait for transmission to complete */
ret = sifive_spi_wait(spi, SIFIVE_SPI_IP_TXWM);
if (ret)
return ret;
}
remaining_len -= n_words;
}
if (flags & SPI_XFER_END)
sifive_spi_clear_cs(spi);
return 0;
}
static int sifive_spi_exec_op(struct spi_slave *slave,
const struct spi_mem_op *op)
{
struct udevice *dev = slave->dev;
struct sifive_spi *spi = dev_get_priv(dev->parent);
unsigned long flags = SPI_XFER_BEGIN;
u8 opcode = op->cmd.opcode;
unsigned int pos = 0;
const void *tx_buf = NULL;
void *rx_buf = NULL;
int op_len, i;
int ret;
if (!op->addr.nbytes && !op->dummy.nbytes && !op->data.nbytes)
flags |= SPI_XFER_END;
spi->fmt_proto = op->cmd.buswidth;
/* send the opcode */
ret = sifive_spi_xfer(dev, 8, (void *)&opcode, NULL, flags);
if (ret < 0) {
dev_err(dev, "failed to xfer opcode\n");
return ret;
}
op_len = op->addr.nbytes + op->dummy.nbytes;
u8 op_buf[op_len];
/* send the addr + dummy */
if (op->addr.nbytes) {
/* fill address */
for (i = 0; i < op->addr.nbytes; i++)
op_buf[pos + i] = op->addr.val >>
(8 * (op->addr.nbytes - i - 1));
pos += op->addr.nbytes;
/* fill dummy */
if (op->dummy.nbytes)
memset(op_buf + pos, 0xff, op->dummy.nbytes);
/* make sure to set end flag, if no data bytes */
if (!op->data.nbytes)
flags |= SPI_XFER_END;
spi->fmt_proto = op->addr.buswidth;
ret = sifive_spi_xfer(dev, op_len * 8, op_buf, NULL, flags);
if (ret < 0) {
dev_err(dev, "failed to xfer addr + dummy\n");
return ret;
}
}
/* send/received the data */
if (op->data.nbytes) {
if (op->data.dir == SPI_MEM_DATA_IN)
rx_buf = op->data.buf.in;
else
tx_buf = op->data.buf.out;
spi->fmt_proto = op->data.buswidth;
ret = sifive_spi_xfer(dev, op->data.nbytes * 8,
tx_buf, rx_buf, SPI_XFER_END);
if (ret) {
dev_err(dev, "failed to xfer data\n");
return ret;
}
}
return 0;
}
static int sifive_spi_set_speed(struct udevice *bus, uint speed)
{
struct sifive_spi *spi = dev_get_priv(bus);
u32 scale;
if (speed > spi->freq)
speed = spi->freq;
/* Cofigure max speed */
scale = (DIV_ROUND_UP(spi->freq >> 1, speed) - 1)
& SIFIVE_SPI_SCKDIV_DIV_MASK;
writel(scale, spi->regs + SIFIVE_SPI_REG_SCKDIV);
return 0;
}
static int sifive_spi_set_mode(struct udevice *bus, uint mode)
{
struct sifive_spi *spi = dev_get_priv(bus);
u32 cr;
/* Switch clock mode bits */
cr = readl(spi->regs + SIFIVE_SPI_REG_SCKMODE) &
~SIFIVE_SPI_SCKMODE_MODE_MASK;
if (mode & SPI_CPHA)
cr |= SIFIVE_SPI_SCKMODE_PHA;
if (mode & SPI_CPOL)
cr |= SIFIVE_SPI_SCKMODE_POL;
writel(cr, spi->regs + SIFIVE_SPI_REG_SCKMODE);
return 0;
}
static int sifive_spi_cs_info(struct udevice *bus, uint cs,
struct spi_cs_info *info)
{
struct sifive_spi *spi = dev_get_priv(bus);
if (cs >= spi->num_cs)
return -EINVAL;
return 0;
}
static void sifive_spi_init_hw(struct sifive_spi *spi)
{
u32 cs_bits;
/* probe the number of CS lines */
spi->cs_inactive = readl(spi->regs + SIFIVE_SPI_REG_CSDEF);
writel(0xffffffffU, spi->regs + SIFIVE_SPI_REG_CSDEF);
cs_bits = readl(spi->regs + SIFIVE_SPI_REG_CSDEF);
writel(spi->cs_inactive, spi->regs + SIFIVE_SPI_REG_CSDEF);
if (!cs_bits) {
printf("Could not auto probe CS lines\n");
return;
}
spi->num_cs = ilog2(cs_bits) + 1;
if (spi->num_cs > SIFIVE_SPI_MAX_CS) {
printf("Invalid number of spi slaves\n");
return;
}
/* Watermark interrupts are disabled by default */
writel(0, spi->regs + SIFIVE_SPI_REG_IE);
/* Default watermark FIFO threshold values */
writel(1, spi->regs + SIFIVE_SPI_REG_TXMARK);
writel(0, spi->regs + SIFIVE_SPI_REG_RXMARK);
/* Set CS/SCK Delays and Inactive Time to defaults */
writel(SIFIVE_SPI_DELAY0_CSSCK(1) | SIFIVE_SPI_DELAY0_SCKCS(1),
spi->regs + SIFIVE_SPI_REG_DELAY0);
writel(SIFIVE_SPI_DELAY1_INTERCS(1) | SIFIVE_SPI_DELAY1_INTERXFR(0),
spi->regs + SIFIVE_SPI_REG_DELAY1);
/* Exit specialized memory-mapped SPI flash mode */
writel(0, spi->regs + SIFIVE_SPI_REG_FCTRL);
}
static int sifive_spi_probe(struct udevice *bus)
{
struct sifive_spi *spi = dev_get_priv(bus);
struct clk clkdev;
int ret;
spi->regs = (void *)(ulong)dev_remap_addr(bus);
if (!spi->regs)
return -ENODEV;
spi->fifo_depth = dev_read_u32_default(bus,
"sifive,fifo-depth",
SIFIVE_SPI_DEFAULT_DEPTH);
spi->bits_per_word = dev_read_u32_default(bus,
"sifive,max-bits-per-word",
SIFIVE_SPI_DEFAULT_BITS);
ret = clk_get_by_index(bus, 0, &clkdev);
if (ret)
return ret;
spi->freq = clk_get_rate(&clkdev);
/* init the sifive spi hw */
sifive_spi_init_hw(spi);
return 0;
}
static const struct spi_controller_mem_ops sifive_spi_mem_ops = {
.exec_op = sifive_spi_exec_op,
};
static const struct dm_spi_ops sifive_spi_ops = {
.xfer = sifive_spi_xfer,
.set_speed = sifive_spi_set_speed,
.set_mode = sifive_spi_set_mode,
.cs_info = sifive_spi_cs_info,
.mem_ops = &sifive_spi_mem_ops,
};
static const struct udevice_id sifive_spi_ids[] = {
{ .compatible = "sifive,spi0" },
{ }
};
U_BOOT_DRIVER(sifive_spi) = {
.name = "sifive_spi",
.id = UCLASS_SPI,
.of_match = sifive_spi_ids,
.ops = &sifive_spi_ops,
.priv_auto = sizeof(struct sifive_spi),
.probe = sifive_spi_probe,
};