u-boot/drivers/spi/xilinx_spi.c

450 lines
11 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0+
/*
* Xilinx SPI driver
*
* Supports 8 bit SPI transfers only, with or w/o FIFO
*
* Based on bfin_spi.c, by way of altera_spi.c
* Copyright (c) 2015 Jagan Teki <jteki@openedev.com>
* Copyright (c) 2012 Stephan Linz <linz@li-pro.net>
* Copyright (c) 2010 Graeme Smecher <graeme.smecher@mail.mcgill.ca>
* Copyright (c) 2010 Thomas Chou <thomas@wytron.com.tw>
* Copyright (c) 2005-2008 Analog Devices Inc.
*/
#include <config.h>
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <log.h>
#include <malloc.h>
#include <spi.h>
#include <spi-mem.h>
#include <asm/io.h>
#include <wait_bit.h>
#include <linux/bitops.h>
/*
* [0]: http://www.xilinx.com/support/documentation
*
* Xilinx SPI Register Definitions
* [1]: [0]/ip_documentation/xps_spi.pdf
* page 8, Register Descriptions
* [2]: [0]/ip_documentation/axi_spi_ds742.pdf
* page 7, Register Overview Table
*/
/* SPI Control Register (spicr), [1] p9, [2] p8 */
#define SPICR_LSB_FIRST BIT(9)
#define SPICR_MASTER_INHIBIT BIT(8)
#define SPICR_MANUAL_SS BIT(7)
#define SPICR_RXFIFO_RESEST BIT(6)
#define SPICR_TXFIFO_RESEST BIT(5)
#define SPICR_CPHA BIT(4)
#define SPICR_CPOL BIT(3)
#define SPICR_MASTER_MODE BIT(2)
#define SPICR_SPE BIT(1)
#define SPICR_LOOP BIT(0)
/* SPI Status Register (spisr), [1] p11, [2] p10 */
#define SPISR_SLAVE_MODE_SELECT BIT(5)
#define SPISR_MODF BIT(4)
#define SPISR_TX_FULL BIT(3)
#define SPISR_TX_EMPTY BIT(2)
#define SPISR_RX_FULL BIT(1)
#define SPISR_RX_EMPTY BIT(0)
/* SPI Data Transmit Register (spidtr), [1] p12, [2] p12 */
#define SPIDTR_8BIT_MASK GENMASK(7, 0)
#define SPIDTR_16BIT_MASK GENMASK(15, 0)
#define SPIDTR_32BIT_MASK GENMASK(31, 0)
/* SPI Data Receive Register (spidrr), [1] p12, [2] p12 */
#define SPIDRR_8BIT_MASK GENMASK(7, 0)
#define SPIDRR_16BIT_MASK GENMASK(15, 0)
#define SPIDRR_32BIT_MASK GENMASK(31, 0)
/* SPI Slave Select Register (spissr), [1] p13, [2] p13 */
#define SPISSR_MASK(cs) (1 << (cs))
#define SPISSR_ACT(cs) ~SPISSR_MASK(cs)
#define SPISSR_OFF ~0UL
/* SPI Software Reset Register (ssr) */
#define SPISSR_RESET_VALUE 0x0a
#define XILSPI_MAX_XFER_BITS 8
#define XILSPI_SPICR_DFLT_ON (SPICR_MANUAL_SS | SPICR_MASTER_MODE | \
SPICR_SPE | SPICR_MASTER_INHIBIT)
#define XILSPI_SPICR_DFLT_OFF (SPICR_MASTER_INHIBIT | SPICR_MANUAL_SS)
#define XILINX_SPI_IDLE_VAL GENMASK(7, 0)
#define XILINX_SPISR_TIMEOUT 10000 /* in milliseconds */
/* xilinx spi register set */
struct xilinx_spi_regs {
u32 __space0__[7];
u32 dgier; /* Device Global Interrupt Enable Register (DGIER) */
u32 ipisr; /* IP Interrupt Status Register (IPISR) */
u32 __space1__;
u32 ipier; /* IP Interrupt Enable Register (IPIER) */
u32 __space2__[5];
u32 srr; /* Softare Reset Register (SRR) */
u32 __space3__[7];
u32 spicr; /* SPI Control Register (SPICR) */
u32 spisr; /* SPI Status Register (SPISR) */
u32 spidtr; /* SPI Data Transmit Register (SPIDTR) */
u32 spidrr; /* SPI Data Receive Register (SPIDRR) */
u32 spissr; /* SPI Slave Select Register (SPISSR) */
u32 spitfor; /* SPI Transmit FIFO Occupancy Register (SPITFOR) */
u32 spirfor; /* SPI Receive FIFO Occupancy Register (SPIRFOR) */
};
/* xilinx spi priv */
struct xilinx_spi_priv {
struct xilinx_spi_regs *regs;
unsigned int freq;
unsigned int mode;
unsigned int fifo_depth;
u8 startup;
};
static int xilinx_spi_probe(struct udevice *bus)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
priv->regs = (struct xilinx_spi_regs *)dev_read_addr(bus);
priv->fifo_depth = dev_read_u32_default(bus, "fifo-size", 0);
writel(SPISSR_RESET_VALUE, &regs->srr);
/*
* Reset RX & TX FIFO
* Enable Manual Slave Select Assertion,
* Set SPI controller into master mode, and enable it
*/
writel(SPICR_RXFIFO_RESEST | SPICR_TXFIFO_RESEST |
SPICR_MANUAL_SS | SPICR_MASTER_MODE | SPICR_SPE,
&regs->spicr);
return 0;
}
static void spi_cs_activate(struct udevice *dev, uint cs)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
writel(SPISSR_ACT(cs), &regs->spissr);
}
static void spi_cs_deactivate(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
u32 reg;
reg = readl(&regs->spicr) | SPICR_RXFIFO_RESEST | SPICR_TXFIFO_RESEST;
writel(reg, &regs->spicr);
writel(SPISSR_OFF, &regs->spissr);
}
static int xilinx_spi_claim_bus(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
writel(SPISSR_OFF, &regs->spissr);
writel(XILSPI_SPICR_DFLT_ON, &regs->spicr);
return 0;
}
static int xilinx_spi_release_bus(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
writel(SPISSR_OFF, &regs->spissr);
writel(XILSPI_SPICR_DFLT_OFF, &regs->spicr);
return 0;
}
static u32 xilinx_spi_fill_txfifo(struct udevice *bus, const u8 *txp,
u32 txbytes)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
unsigned char d;
u32 i = 0;
while (txbytes && !(readl(&regs->spisr) & SPISR_TX_FULL) &&
i < priv->fifo_depth) {
d = txp ? *txp++ : XILINX_SPI_IDLE_VAL;
debug("spi_xfer: tx:%x ", d);
/* write out and wait for processing (receive data) */
writel(d & SPIDTR_8BIT_MASK, &regs->spidtr);
txbytes--;
i++;
}
return i;
}
static u32 xilinx_spi_read_rxfifo(struct udevice *bus, u8 *rxp, u32 rxbytes)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
unsigned char d;
unsigned int i = 0;
while (rxbytes && !(readl(&regs->spisr) & SPISR_RX_EMPTY)) {
d = readl(&regs->spidrr) & SPIDRR_8BIT_MASK;
if (rxp)
*rxp++ = d;
debug("spi_xfer: rx:%x\n", d);
rxbytes--;
i++;
}
debug("Rx_done\n");
return i;
}
static int start_transfer(struct spi_slave *spi, const void *dout, void *din, u32 len)
{
struct udevice *bus = spi->dev->parent;
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
u32 count, txbytes, rxbytes;
int reg, ret;
const unsigned char *txp = (const unsigned char *)dout;
unsigned char *rxp = (unsigned char *)din;
txbytes = len;
rxbytes = len;
while (txbytes || rxbytes) {
/* Disable master transaction */
reg = readl(&regs->spicr) | SPICR_MASTER_INHIBIT;
writel(reg, &regs->spicr);
count = xilinx_spi_fill_txfifo(bus, txp, txbytes);
/* Enable master transaction */
reg = readl(&regs->spicr) & ~SPICR_MASTER_INHIBIT;
writel(reg, &regs->spicr);
txbytes -= count;
if (txp)
txp += count;
ret = wait_for_bit_le32(&regs->spisr, SPISR_TX_EMPTY, true,
XILINX_SPISR_TIMEOUT, false);
if (ret < 0) {
printf("XILSPI error: Xfer timeout\n");
return ret;
}
reg = readl(&regs->spicr) | SPICR_MASTER_INHIBIT;
writel(reg, &regs->spicr);
count = xilinx_spi_read_rxfifo(bus, rxp, rxbytes);
rxbytes -= count;
if (rxp)
rxp += count;
}
return 0;
}
static void xilinx_spi_startup_block(struct spi_slave *spi)
{
struct dm_spi_slave_plat *slave_plat =
dev_get_parent_plat(spi->dev);
unsigned char txp;
unsigned char rxp[8];
/*
* Perform a dummy read as a work around for
* the startup block issue.
*/
spi_cs_activate(spi->dev, slave_plat->cs);
txp = 0x9f;
start_transfer(spi, (void *)&txp, NULL, 1);
start_transfer(spi, NULL, (void *)rxp, 6);
spi_cs_deactivate(spi->dev);
}
static int xilinx_spi_mem_exec_op(struct spi_slave *spi,
const struct spi_mem_op *op)
{
struct dm_spi_slave_plat *slave_plat =
dev_get_parent_plat(spi->dev);
static u32 startup;
u32 dummy_len, ret;
/*
* This is the work around for the startup block issue in
* the spi controller. SPI clock is passing through STARTUP
* block to FLASH. STARTUP block don't provide clock as soon
* as QSPI provides command. So first command fails.
*/
if (!startup) {
xilinx_spi_startup_block(spi);
startup++;
}
spi_cs_activate(spi->dev, slave_plat->cs);
if (op->cmd.opcode) {
ret = start_transfer(spi, (void *)&op->cmd.opcode, NULL, 1);
if (ret)
goto done;
}
if (op->addr.nbytes) {
int i;
u8 addr_buf[4];
for (i = 0; i < op->addr.nbytes; i++)
addr_buf[i] = op->addr.val >>
(8 * (op->addr.nbytes - i - 1));
ret = start_transfer(spi, (void *)addr_buf, NULL,
op->addr.nbytes);
if (ret)
goto done;
}
if (op->dummy.nbytes) {
dummy_len = (op->dummy.nbytes * op->data.buswidth) /
op->dummy.buswidth;
ret = start_transfer(spi, NULL, NULL, dummy_len);
if (ret)
goto done;
}
if (op->data.nbytes) {
if (op->data.dir == SPI_MEM_DATA_IN) {
ret = start_transfer(spi, NULL,
op->data.buf.in, op->data.nbytes);
} else {
ret = start_transfer(spi, op->data.buf.out,
NULL, op->data.nbytes);
}
if (ret)
goto done;
}
done:
spi_cs_deactivate(spi->dev);
return ret;
}
static int xilinx_qspi_check_buswidth(struct spi_slave *slave, u8 width)
{
u32 mode = slave->mode;
switch (width) {
case 1:
return 0;
case 2:
if (mode & SPI_RX_DUAL)
return 0;
break;
case 4:
if (mode & SPI_RX_QUAD)
return 0;
break;
}
return -EOPNOTSUPP;
}
bool xilinx_qspi_mem_exec_op(struct spi_slave *slave,
const struct spi_mem_op *op)
{
if (xilinx_qspi_check_buswidth(slave, op->cmd.buswidth))
return false;
if (op->addr.nbytes &&
xilinx_qspi_check_buswidth(slave, op->addr.buswidth))
return false;
if (op->dummy.nbytes &&
xilinx_qspi_check_buswidth(slave, op->dummy.buswidth))
return false;
if (op->data.dir != SPI_MEM_NO_DATA &&
xilinx_qspi_check_buswidth(slave, op->data.buswidth))
return false;
return true;
}
static int xilinx_spi_set_speed(struct udevice *bus, uint speed)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
priv->freq = speed;
debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);
return 0;
}
static int xilinx_spi_set_mode(struct udevice *bus, uint mode)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
u32 spicr;
spicr = readl(&regs->spicr);
if (mode & SPI_LSB_FIRST)
spicr |= SPICR_LSB_FIRST;
if (mode & SPI_CPHA)
spicr |= SPICR_CPHA;
if (mode & SPI_CPOL)
spicr |= SPICR_CPOL;
if (mode & SPI_LOOP)
spicr |= SPICR_LOOP;
writel(spicr, &regs->spicr);
priv->mode = mode;
debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
return 0;
}
static const struct spi_controller_mem_ops xilinx_spi_mem_ops = {
.exec_op = xilinx_spi_mem_exec_op,
.supports_op = xilinx_qspi_mem_exec_op,
};
static const struct dm_spi_ops xilinx_spi_ops = {
.claim_bus = xilinx_spi_claim_bus,
.release_bus = xilinx_spi_release_bus,
.set_speed = xilinx_spi_set_speed,
.set_mode = xilinx_spi_set_mode,
.mem_ops = &xilinx_spi_mem_ops,
};
static const struct udevice_id xilinx_spi_ids[] = {
{ .compatible = "xlnx,xps-spi-2.00.a" },
{ .compatible = "xlnx,xps-spi-2.00.b" },
{ }
};
U_BOOT_DRIVER(xilinx_spi) = {
.name = "xilinx_spi",
.id = UCLASS_SPI,
.of_match = xilinx_spi_ids,
.ops = &xilinx_spi_ops,
.priv_auto = sizeof(struct xilinx_spi_priv),
.probe = xilinx_spi_probe,
};