u-boot/drivers/spi/zynq_qspi.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2013 Xilinx, Inc.
* (C) Copyright 2015 Jagan Teki <jteki@openedev.com>
*
* Xilinx Zynq Quad-SPI(QSPI) controller driver (master mode only)
*/
#include <clk.h>
#include <common.h>
#include <dm.h>
#include <dm/device_compat.h>
#include <log.h>
#include <malloc.h>
#include <spi.h>
#include <asm/io.h>
#include <linux/bitops.h>
DECLARE_GLOBAL_DATA_PTR;
/* zynq qspi register bit masks ZYNQ_QSPI_<REG>_<BIT>_MASK */
#define ZYNQ_QSPI_CR_IFMODE_MASK BIT(31) /* Flash intrface mode*/
#define ZYNQ_QSPI_CR_MSA_MASK BIT(15) /* Manual start enb */
#define ZYNQ_QSPI_CR_MCS_MASK BIT(14) /* Manual chip select */
#define ZYNQ_QSPI_CR_PCS_MASK BIT(10) /* Peri chip select */
#define ZYNQ_QSPI_CR_FW_MASK GENMASK(7, 6) /* FIFO width */
#define ZYNQ_QSPI_CR_SS_MASK GENMASK(13, 10) /* Slave Select */
#define ZYNQ_QSPI_CR_BAUD_MASK GENMASK(5, 3) /* Baud rate div */
#define ZYNQ_QSPI_CR_CPHA_MASK BIT(2) /* Clock phase */
#define ZYNQ_QSPI_CR_CPOL_MASK BIT(1) /* Clock polarity */
#define ZYNQ_QSPI_CR_MSTREN_MASK BIT(0) /* Mode select */
#define ZYNQ_QSPI_IXR_RXNEMPTY_MASK BIT(4) /* RX_FIFO_not_empty */
#define ZYNQ_QSPI_IXR_TXOW_MASK BIT(2) /* TX_FIFO_not_full */
#define ZYNQ_QSPI_IXR_ALL_MASK GENMASK(6, 0) /* All IXR bits */
#define ZYNQ_QSPI_ENR_SPI_EN_MASK BIT(0) /* SPI Enable */
#define ZYNQ_QSPI_LQSPICFG_LQMODE_MASK BIT(31) /* Linear QSPI Mode */
/* zynq qspi Transmit Data Register */
#define ZYNQ_QSPI_TXD_00_00_OFFSET 0x1C /* Transmit 4-byte inst */
#define ZYNQ_QSPI_TXD_00_01_OFFSET 0x80 /* Transmit 1-byte inst */
#define ZYNQ_QSPI_TXD_00_10_OFFSET 0x84 /* Transmit 2-byte inst */
#define ZYNQ_QSPI_TXD_00_11_OFFSET 0x88 /* Transmit 3-byte inst */
#define ZYNQ_QSPI_TXFIFO_THRESHOLD 1 /* Tx FIFO threshold level*/
#define ZYNQ_QSPI_RXFIFO_THRESHOLD 32 /* Rx FIFO threshold level */
#define ZYNQ_QSPI_CR_BAUD_MAX 8 /* Baud rate divisor max val */
#define ZYNQ_QSPI_CR_BAUD_SHIFT 3 /* Baud rate divisor shift */
#define ZYNQ_QSPI_CR_SS_SHIFT 10 /* Slave select shift */
#define ZYNQ_QSPI_FIFO_DEPTH 63
#define ZYNQ_QSPI_WAIT (CONFIG_SYS_HZ / 100) /* 10 ms */
/* zynq qspi register set */
struct zynq_qspi_regs {
u32 cr; /* 0x00 */
u32 isr; /* 0x04 */
u32 ier; /* 0x08 */
u32 idr; /* 0x0C */
u32 imr; /* 0x10 */
u32 enr; /* 0x14 */
u32 dr; /* 0x18 */
u32 txd0r; /* 0x1C */
u32 drxr; /* 0x20 */
u32 sicr; /* 0x24 */
u32 txftr; /* 0x28 */
u32 rxftr; /* 0x2C */
u32 gpior; /* 0x30 */
u32 reserved0[19];
u32 txd1r; /* 0x80 */
u32 txd2r; /* 0x84 */
u32 txd3r; /* 0x88 */
u32 reserved1[5];
u32 lqspicfg; /* 0xA0 */
u32 lqspists; /* 0xA4 */
};
/* zynq qspi platform data */
struct zynq_qspi_plat {
struct zynq_qspi_regs *regs;
u32 frequency; /* input frequency */
u32 speed_hz;
};
/* zynq qspi priv */
struct zynq_qspi_priv {
struct zynq_qspi_regs *regs;
u8 cs;
u8 mode;
u8 fifo_depth;
u32 freq; /* required frequency */
const void *tx_buf;
void *rx_buf;
unsigned len;
int bytes_to_transfer;
int bytes_to_receive;
unsigned int is_inst;
unsigned cs_change:1;
};
static int zynq_qspi_of_to_plat(struct udevice *bus)
{
struct zynq_qspi_plat *plat = bus->plat;
const void *blob = gd->fdt_blob;
int node = dev_of_offset(bus);
plat->regs = (struct zynq_qspi_regs *)fdtdec_get_addr(blob,
node, "reg");
return 0;
}
/**
* zynq_qspi_init_hw - Initialize the hardware
* @priv: Pointer to the zynq_qspi_priv structure
*
* The default settings of the QSPI controller's configurable parameters on
* reset are
* - Master mode
* - Baud rate divisor is set to 2
* - Threshold value for TX FIFO not full interrupt is set to 1
* - Flash memory interface mode enabled
* - Size of the word to be transferred as 8 bit
* This function performs the following actions
* - Disable and clear all the interrupts
* - Enable manual slave select
* - Enable auto start
* - Deselect all the chip select lines
* - Set the size of the word to be transferred as 32 bit
* - Set the little endian mode of TX FIFO and
* - Enable the QSPI controller
*/
static void zynq_qspi_init_hw(struct zynq_qspi_priv *priv)
{
struct zynq_qspi_regs *regs = priv->regs;
u32 confr;
/* Disable QSPI */
writel(~ZYNQ_QSPI_ENR_SPI_EN_MASK, &regs->enr);
/* Disable Interrupts */
writel(ZYNQ_QSPI_IXR_ALL_MASK, &regs->idr);
/* Clear the TX and RX threshold reg */
writel(ZYNQ_QSPI_TXFIFO_THRESHOLD, &regs->txftr);
writel(ZYNQ_QSPI_RXFIFO_THRESHOLD, &regs->rxftr);
/* Clear the RX FIFO */
while (readl(&regs->isr) & ZYNQ_QSPI_IXR_RXNEMPTY_MASK)
readl(&regs->drxr);
/* Clear Interrupts */
writel(ZYNQ_QSPI_IXR_ALL_MASK, &regs->isr);
/* Manual slave select and Auto start */
confr = readl(&regs->cr);
confr &= ~ZYNQ_QSPI_CR_MSA_MASK;
confr |= ZYNQ_QSPI_CR_IFMODE_MASK | ZYNQ_QSPI_CR_MCS_MASK |
ZYNQ_QSPI_CR_PCS_MASK | ZYNQ_QSPI_CR_FW_MASK |
ZYNQ_QSPI_CR_MSTREN_MASK;
writel(confr, &regs->cr);
/* Disable the LQSPI feature */
confr = readl(&regs->lqspicfg);
confr &= ~ZYNQ_QSPI_LQSPICFG_LQMODE_MASK;
writel(confr, &regs->lqspicfg);
/* Enable SPI */
writel(ZYNQ_QSPI_ENR_SPI_EN_MASK, &regs->enr);
}
static int zynq_qspi_probe(struct udevice *bus)
{
struct zynq_qspi_plat *plat = dev_get_plat(bus);
struct zynq_qspi_priv *priv = dev_get_priv(bus);
struct clk clk;
unsigned long clock;
int ret;
priv->regs = plat->regs;
priv->fifo_depth = ZYNQ_QSPI_FIFO_DEPTH;
ret = clk_get_by_name(bus, "ref_clk", &clk);
if (ret < 0) {
dev_err(bus, "failed to get clock\n");
return ret;
}
clock = clk_get_rate(&clk);
if (IS_ERR_VALUE(clock)) {
dev_err(bus, "failed to get rate\n");
return clock;
}
ret = clk_enable(&clk);
if (ret && ret != -ENOSYS) {
dev_err(bus, "failed to enable clock\n");
return ret;
}
/* init the zynq spi hw */
zynq_qspi_init_hw(priv);
plat->frequency = clock;
plat->speed_hz = plat->frequency / 2;
debug("%s: max-frequency=%d\n", __func__, plat->speed_hz);
return 0;
}
/**
* zynq_qspi_read_data - Copy data to RX buffer
* @priv: Pointer to the zynq_qspi_priv structure
* @data: The 32 bit variable where data is stored
* @size: Number of bytes to be copied from data to RX buffer
*/
static void zynq_qspi_read_data(struct zynq_qspi_priv *priv, u32 data, u8 size)
{
u8 byte3;
debug("%s: data 0x%04x rx_buf addr: 0x%08x size %d\n", __func__ ,
data, (unsigned)(priv->rx_buf), size);
if (priv->rx_buf) {
switch (size) {
case 1:
*((u8 *)priv->rx_buf) = data;
priv->rx_buf += 1;
break;
case 2:
*((u16 *)priv->rx_buf) = data;
priv->rx_buf += 2;
break;
case 3:
*((u16 *)priv->rx_buf) = data;
priv->rx_buf += 2;
byte3 = (u8)(data >> 16);
*((u8 *)priv->rx_buf) = byte3;
priv->rx_buf += 1;
break;
case 4:
/* Can not assume word aligned buffer */
memcpy(priv->rx_buf, &data, size);
priv->rx_buf += 4;
break;
default:
/* This will never execute */
break;
}
}
priv->bytes_to_receive -= size;
if (priv->bytes_to_receive < 0)
priv->bytes_to_receive = 0;
}
/**
* zynq_qspi_write_data - Copy data from TX buffer
* @priv: Pointer to the zynq_qspi_priv structure
* @data: Pointer to the 32 bit variable where data is to be copied
* @size: Number of bytes to be copied from TX buffer to data
*/
static void zynq_qspi_write_data(struct zynq_qspi_priv *priv,
u32 *data, u8 size)
{
if (priv->tx_buf) {
switch (size) {
case 1:
*data = *((u8 *)priv->tx_buf);
priv->tx_buf += 1;
*data |= 0xFFFFFF00;
break;
case 2:
*data = *((u16 *)priv->tx_buf);
priv->tx_buf += 2;
*data |= 0xFFFF0000;
break;
case 3:
*data = *((u16 *)priv->tx_buf);
priv->tx_buf += 2;
*data |= (*((u8 *)priv->tx_buf) << 16);
priv->tx_buf += 1;
*data |= 0xFF000000;
break;
case 4:
/* Can not assume word aligned buffer */
memcpy(data, priv->tx_buf, size);
priv->tx_buf += 4;
break;
default:
/* This will never execute */
break;
}
} else {
*data = 0;
}
debug("%s: data 0x%08x tx_buf addr: 0x%08x size %d\n", __func__,
*data, (u32)priv->tx_buf, size);
priv->bytes_to_transfer -= size;
if (priv->bytes_to_transfer < 0)
priv->bytes_to_transfer = 0;
}
/**
* zynq_qspi_chipselect - Select or deselect the chip select line
* @priv: Pointer to the zynq_qspi_priv structure
* @is_on: Select(1) or deselect (0) the chip select line
*/
static void zynq_qspi_chipselect(struct zynq_qspi_priv *priv, int is_on)
{
u32 confr;
struct zynq_qspi_regs *regs = priv->regs;
confr = readl(&regs->cr);
if (is_on) {
/* Select the slave */
confr &= ~ZYNQ_QSPI_CR_SS_MASK;
confr |= (~(1 << priv->cs) << ZYNQ_QSPI_CR_SS_SHIFT) &
ZYNQ_QSPI_CR_SS_MASK;
} else
/* Deselect the slave */
confr |= ZYNQ_QSPI_CR_SS_MASK;
writel(confr, &regs->cr);
}
/**
* zynq_qspi_fill_tx_fifo - Fills the TX FIFO with as many bytes as possible
* @priv: Pointer to the zynq_qspi_priv structure
* @size: Number of bytes to be copied to fifo
*/
static void zynq_qspi_fill_tx_fifo(struct zynq_qspi_priv *priv, u32 size)
{
u32 data = 0;
u32 fifocount = 0;
unsigned len, offset;
struct zynq_qspi_regs *regs = priv->regs;
static const unsigned offsets[4] = {
ZYNQ_QSPI_TXD_00_00_OFFSET, ZYNQ_QSPI_TXD_00_01_OFFSET,
ZYNQ_QSPI_TXD_00_10_OFFSET, ZYNQ_QSPI_TXD_00_11_OFFSET };
while ((fifocount < size) &&
(priv->bytes_to_transfer > 0)) {
if (priv->bytes_to_transfer >= 4) {
if (priv->tx_buf) {
memcpy(&data, priv->tx_buf, 4);
priv->tx_buf += 4;
} else {
data = 0;
}
writel(data, &regs->txd0r);
priv->bytes_to_transfer -= 4;
fifocount++;
} else {
/* Write TXD1, TXD2, TXD3 only if TxFIFO is empty. */
if (!(readl(&regs->isr)
& ZYNQ_QSPI_IXR_TXOW_MASK) &&
!priv->rx_buf)
return;
len = priv->bytes_to_transfer;
zynq_qspi_write_data(priv, &data, len);
offset = (priv->rx_buf) ? offsets[0] : offsets[len];
writel(data, &regs->cr + (offset / 4));
}
}
}
/**
* zynq_qspi_irq_poll - Interrupt service routine of the QSPI controller
* @priv: Pointer to the zynq_qspi structure
*
* This function handles TX empty and Mode Fault interrupts only.
* On TX empty interrupt this function reads the received data from RX FIFO and
* fills the TX FIFO if there is any data remaining to be transferred.
* On Mode Fault interrupt this function indicates that transfer is completed,
* the SPI subsystem will identify the error as the remaining bytes to be
* transferred is non-zero.
*
* returns: 0 for poll timeout
* 1 transfer operation complete
*/
static int zynq_qspi_irq_poll(struct zynq_qspi_priv *priv)
{
struct zynq_qspi_regs *regs = priv->regs;
u32 rxindex = 0;
u32 rxcount;
u32 status, timeout;
/* Poll until any of the interrupt status bits are set */
timeout = get_timer(0);
do {
status = readl(&regs->isr);
} while ((status == 0) &&
(get_timer(timeout) < ZYNQ_QSPI_WAIT));
if (status == 0) {
printf("zynq_qspi_irq_poll: Timeout!\n");
return -ETIMEDOUT;
}
writel(status, &regs->isr);
/* Disable all interrupts */
writel(ZYNQ_QSPI_IXR_ALL_MASK, &regs->idr);
if ((status & ZYNQ_QSPI_IXR_TXOW_MASK) ||
(status & ZYNQ_QSPI_IXR_RXNEMPTY_MASK)) {
/*
* This bit is set when Tx FIFO has < THRESHOLD entries. We have
* the THRESHOLD value set to 1, so this bit indicates Tx FIFO
* is empty
*/
rxcount = priv->bytes_to_receive - priv->bytes_to_transfer;
rxcount = (rxcount % 4) ? ((rxcount/4)+1) : (rxcount/4);
while ((rxindex < rxcount) &&
(rxindex < ZYNQ_QSPI_RXFIFO_THRESHOLD)) {
/* Read out the data from the RX FIFO */
u32 data;
data = readl(&regs->drxr);
if (priv->bytes_to_receive >= 4) {
if (priv->rx_buf) {
memcpy(priv->rx_buf, &data, 4);
priv->rx_buf += 4;
}
priv->bytes_to_receive -= 4;
} else {
zynq_qspi_read_data(priv, data,
priv->bytes_to_receive);
}
rxindex++;
}
if (priv->bytes_to_transfer) {
/* There is more data to send */
zynq_qspi_fill_tx_fifo(priv,
ZYNQ_QSPI_RXFIFO_THRESHOLD);
writel(ZYNQ_QSPI_IXR_ALL_MASK, &regs->ier);
} else {
/*
* If transfer and receive is completed then only send
* complete signal
*/
if (!priv->bytes_to_receive) {
/* return operation complete */
writel(ZYNQ_QSPI_IXR_ALL_MASK,
&regs->idr);
return 1;
}
}
}
return 0;
}
/**
* zynq_qspi_start_transfer - Initiates the QSPI transfer
* @priv: Pointer to the zynq_qspi_priv structure
*
* This function fills the TX FIFO, starts the QSPI transfer, and waits for the
* transfer to be completed.
*
* returns: Number of bytes transferred in the last transfer
*/
static int zynq_qspi_start_transfer(struct zynq_qspi_priv *priv)
{
u32 data = 0;
struct zynq_qspi_regs *regs = priv->regs;
debug("%s: qspi: 0x%08x transfer: 0x%08x len: %d\n", __func__,
(u32)priv, (u32)priv, priv->len);
priv->bytes_to_transfer = priv->len;
priv->bytes_to_receive = priv->len;
if (priv->len < 4)
zynq_qspi_fill_tx_fifo(priv, priv->len);
else
zynq_qspi_fill_tx_fifo(priv, priv->fifo_depth);
writel(ZYNQ_QSPI_IXR_ALL_MASK, &regs->ier);
/* wait for completion */
do {
data = zynq_qspi_irq_poll(priv);
} while (data == 0);
return (priv->len) - (priv->bytes_to_transfer);
}
static int zynq_qspi_transfer(struct zynq_qspi_priv *priv)
{
unsigned cs_change = 1;
int status = 0;
while (1) {
/* Select the chip if required */
if (cs_change)
zynq_qspi_chipselect(priv, 1);
cs_change = priv->cs_change;
if (!priv->tx_buf && !priv->rx_buf && priv->len) {
status = -1;
break;
}
/* Request the transfer */
if (priv->len) {
status = zynq_qspi_start_transfer(priv);
priv->is_inst = 0;
}
if (status != priv->len) {
if (status > 0)
status = -EMSGSIZE;
debug("zynq_qspi_transfer:%d len:%d\n",
status, priv->len);
break;
}
status = 0;
if (cs_change)
/* Deselect the chip */
zynq_qspi_chipselect(priv, 0);
break;
}
return status;
}
static int zynq_qspi_claim_bus(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct zynq_qspi_priv *priv = dev_get_priv(bus);
struct zynq_qspi_regs *regs = priv->regs;
writel(ZYNQ_QSPI_ENR_SPI_EN_MASK, &regs->enr);
return 0;
}
static int zynq_qspi_release_bus(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct zynq_qspi_priv *priv = dev_get_priv(bus);
struct zynq_qspi_regs *regs = priv->regs;
writel(~ZYNQ_QSPI_ENR_SPI_EN_MASK, &regs->enr);
return 0;
}
static int zynq_qspi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = dev->parent;
struct zynq_qspi_priv *priv = dev_get_priv(bus);
struct dm_spi_slave_plat *slave_plat = dev_get_parent_plat(dev);
priv->cs = slave_plat->cs;
priv->tx_buf = dout;
priv->rx_buf = din;
priv->len = bitlen / 8;
debug("zynq_qspi_xfer: bus:%i cs:%i bitlen:%i len:%i flags:%lx\n",
bus->seq, slave_plat->cs, bitlen, priv->len, flags);
/*
* Festering sore.
* Assume that the beginning of a transfer with bits to
* transmit must contain a device command.
*/
if (dout && flags & SPI_XFER_BEGIN)
priv->is_inst = 1;
else
priv->is_inst = 0;
if (flags & SPI_XFER_END)
priv->cs_change = 1;
else
priv->cs_change = 0;
zynq_qspi_transfer(priv);
return 0;
}
static int zynq_qspi_set_speed(struct udevice *bus, uint speed)
{
struct zynq_qspi_plat *plat = bus->plat;
struct zynq_qspi_priv *priv = dev_get_priv(bus);
struct zynq_qspi_regs *regs = priv->regs;
uint32_t confr;
u8 baud_rate_val = 0;
if (speed > plat->frequency)
speed = plat->frequency;
/* Set the clock frequency */
confr = readl(&regs->cr);
if (speed == 0) {
/* Set baudrate x8, if the freq is 0 */
baud_rate_val = 0x2;
} else if (plat->speed_hz != speed) {
while ((baud_rate_val < ZYNQ_QSPI_CR_BAUD_MAX) &&
((plat->frequency /
(2 << baud_rate_val)) > speed))
baud_rate_val++;
plat->speed_hz = speed / (2 << baud_rate_val);
}
confr &= ~ZYNQ_QSPI_CR_BAUD_MASK;
confr |= (baud_rate_val << ZYNQ_QSPI_CR_BAUD_SHIFT);
writel(confr, &regs->cr);
priv->freq = speed;
debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);
return 0;
}
static int zynq_qspi_set_mode(struct udevice *bus, uint mode)
{
struct zynq_qspi_priv *priv = dev_get_priv(bus);
struct zynq_qspi_regs *regs = priv->regs;
uint32_t confr;
/* Set the SPI Clock phase and polarities */
confr = readl(&regs->cr);
confr &= ~(ZYNQ_QSPI_CR_CPHA_MASK | ZYNQ_QSPI_CR_CPOL_MASK);
if (mode & SPI_CPHA)
confr |= ZYNQ_QSPI_CR_CPHA_MASK;
if (mode & SPI_CPOL)
confr |= ZYNQ_QSPI_CR_CPOL_MASK;
writel(confr, &regs->cr);
priv->mode = mode;
debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
return 0;
}
static const struct dm_spi_ops zynq_qspi_ops = {
.claim_bus = zynq_qspi_claim_bus,
.release_bus = zynq_qspi_release_bus,
.xfer = zynq_qspi_xfer,
.set_speed = zynq_qspi_set_speed,
.set_mode = zynq_qspi_set_mode,
};
static const struct udevice_id zynq_qspi_ids[] = {
{ .compatible = "xlnx,zynq-qspi-1.0" },
{ }
};
U_BOOT_DRIVER(zynq_qspi) = {
.name = "zynq_qspi",
.id = UCLASS_SPI,
.of_match = zynq_qspi_ids,
.ops = &zynq_qspi_ops,
.of_to_plat = zynq_qspi_of_to_plat,
.plat_auto = sizeof(struct zynq_qspi_plat),
.priv_auto = sizeof(struct zynq_qspi_priv),
.probe = zynq_qspi_probe,
};