blob: 285b006f6a77fd2bc2b08b8459ab785e9d085e19 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2013 Xilinx, Inc.
* (C) Copyright 2015 Jagan Teki <jteki@openedev.com>
*
* Xilinx Zynq PS SPI controller driver (master mode only)
*/
#include <common.h>
#include <dm.h>
#include <dm/device_compat.h>
#include <log.h>
#include <malloc.h>
#include <spi.h>
#include <time.h>
#include <clk.h>
#include <asm/io.h>
#include <linux/bitops.h>
#include <linux/delay.h>
DECLARE_GLOBAL_DATA_PTR;
/* zynq spi register bit masks ZYNQ_SPI_<REG>_<BIT>_MASK */
#define ZYNQ_SPI_CR_MSA_MASK BIT(15) /* Manual start enb */
#define ZYNQ_SPI_CR_MCS_MASK BIT(14) /* Manual chip select */
#define ZYNQ_SPI_CR_CS_MASK GENMASK(13, 10) /* Chip select */
#define ZYNQ_SPI_CR_BAUD_MASK GENMASK(5, 3) /* Baud rate div */
#define ZYNQ_SPI_CR_CPHA_MASK BIT(2) /* Clock phase */
#define ZYNQ_SPI_CR_CPOL_MASK BIT(1) /* Clock polarity */
#define ZYNQ_SPI_CR_MSTREN_MASK BIT(0) /* Mode select */
#define ZYNQ_SPI_IXR_RXNEMPTY_MASK BIT(4) /* RX_FIFO_not_empty */
#define ZYNQ_SPI_IXR_TXOW_MASK BIT(2) /* TX_FIFO_not_full */
#define ZYNQ_SPI_IXR_ALL_MASK GENMASK(6, 0) /* All IXR bits */
#define ZYNQ_SPI_ENR_SPI_EN_MASK BIT(0) /* SPI Enable */
#define ZYNQ_SPI_CR_BAUD_MAX 8 /* Baud rate divisor max val */
#define ZYNQ_SPI_CR_BAUD_SHIFT 3 /* Baud rate divisor shift */
#define ZYNQ_SPI_CR_SS_SHIFT 10 /* Slave select shift */
#define ZYNQ_SPI_FIFO_DEPTH 128
#define ZYNQ_SPI_WAIT (CONFIG_SYS_HZ / 100) /* 10 ms */
/* zynq spi register set */
struct zynq_spi_regs {
u32 cr; /* 0x00 */
u32 isr; /* 0x04 */
u32 ier; /* 0x08 */
u32 idr; /* 0x0C */
u32 imr; /* 0x10 */
u32 enr; /* 0x14 */
u32 dr; /* 0x18 */
u32 txdr; /* 0x1C */
u32 rxdr; /* 0x20 */
};
/* zynq spi platform data */
struct zynq_spi_platdata {
struct zynq_spi_regs *regs;
u32 frequency; /* input frequency */
u32 speed_hz;
uint deactivate_delay_us; /* Delay to wait after deactivate */
uint activate_delay_us; /* Delay to wait after activate */
};
/* zynq spi priv */
struct zynq_spi_priv {
struct zynq_spi_regs *regs;
u8 cs;
u8 mode;
ulong last_transaction_us; /* Time of last transaction end */
u8 fifo_depth;
u32 freq; /* required frequency */
};
static int zynq_spi_of_to_plat(struct udevice *bus)
{
struct zynq_spi_platdata *plat = bus->plat;
const void *blob = gd->fdt_blob;
int node = dev_of_offset(bus);
plat->regs = dev_read_addr_ptr(bus);
plat->deactivate_delay_us = fdtdec_get_int(blob, node,
"spi-deactivate-delay", 0);
plat->activate_delay_us = fdtdec_get_int(blob, node,
"spi-activate-delay", 0);
return 0;
}
static void zynq_spi_init_hw(struct zynq_spi_priv *priv)
{
struct zynq_spi_regs *regs = priv->regs;
u32 confr;
/* Disable SPI */
confr = ZYNQ_SPI_ENR_SPI_EN_MASK;
writel(~confr, &regs->enr);
/* Disable Interrupts */
writel(ZYNQ_SPI_IXR_ALL_MASK, &regs->idr);
/* Clear RX FIFO */
while (readl(&regs->isr) &
ZYNQ_SPI_IXR_RXNEMPTY_MASK)
readl(&regs->rxdr);
/* Clear Interrupts */
writel(ZYNQ_SPI_IXR_ALL_MASK, &regs->isr);
/* Manual slave select and Auto start */
confr = ZYNQ_SPI_CR_MCS_MASK | ZYNQ_SPI_CR_CS_MASK |
ZYNQ_SPI_CR_MSTREN_MASK;
confr &= ~ZYNQ_SPI_CR_MSA_MASK;
writel(confr, &regs->cr);
/* Enable SPI */
writel(ZYNQ_SPI_ENR_SPI_EN_MASK, &regs->enr);
}
static int zynq_spi_probe(struct udevice *bus)
{
struct zynq_spi_platdata *plat = dev_get_plat(bus);
struct zynq_spi_priv *priv = dev_get_priv(bus);
struct clk clk;
unsigned long clock;
int ret;
priv->regs = plat->regs;
priv->fifo_depth = ZYNQ_SPI_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_spi_init_hw(priv);
plat->frequency = clock;
plat->speed_hz = plat->frequency / 2;
debug("%s: max-frequency=%d\n", __func__, plat->speed_hz);
return 0;
}
static void spi_cs_activate(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct zynq_spi_platdata *plat = bus->plat;
struct zynq_spi_priv *priv = dev_get_priv(bus);
struct zynq_spi_regs *regs = priv->regs;
u32 cr;
/* If it's too soon to do another transaction, wait */
if (plat->deactivate_delay_us && priv->last_transaction_us) {
ulong delay_us; /* The delay completed so far */
delay_us = timer_get_us() - priv->last_transaction_us;
if (delay_us < plat->deactivate_delay_us)
udelay(plat->deactivate_delay_us - delay_us);
}
clrbits_le32(&regs->cr, ZYNQ_SPI_CR_CS_MASK);
cr = readl(&regs->cr);
/*
* CS cal logic: CS[13:10]
* xxx0 - cs0
* xx01 - cs1
* x011 - cs2
*/
cr |= (~(1 << priv->cs) << ZYNQ_SPI_CR_SS_SHIFT) & ZYNQ_SPI_CR_CS_MASK;
writel(cr, &regs->cr);
if (plat->activate_delay_us)
udelay(plat->activate_delay_us);
}
static void spi_cs_deactivate(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct zynq_spi_platdata *plat = bus->plat;
struct zynq_spi_priv *priv = dev_get_priv(bus);
struct zynq_spi_regs *regs = priv->regs;
setbits_le32(&regs->cr, ZYNQ_SPI_CR_CS_MASK);
/* Remember time of this transaction so we can honour the bus delay */
if (plat->deactivate_delay_us)
priv->last_transaction_us = timer_get_us();
}
static int zynq_spi_claim_bus(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct zynq_spi_priv *priv = dev_get_priv(bus);
struct zynq_spi_regs *regs = priv->regs;
writel(ZYNQ_SPI_ENR_SPI_EN_MASK, &regs->enr);
return 0;
}
static int zynq_spi_release_bus(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct zynq_spi_priv *priv = dev_get_priv(bus);
struct zynq_spi_regs *regs = priv->regs;
u32 confr;
confr = ZYNQ_SPI_ENR_SPI_EN_MASK;
writel(~confr, &regs->enr);
return 0;
}
static int zynq_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = dev->parent;
struct zynq_spi_priv *priv = dev_get_priv(bus);
struct zynq_spi_regs *regs = priv->regs;
struct dm_spi_slave_platdata *slave_plat = dev_get_parent_plat(dev);
u32 len = bitlen / 8;
u32 tx_len = len, rx_len = len, tx_tvl;
const u8 *tx_buf = dout;
u8 *rx_buf = din, buf;
u32 ts, status;
debug("spi_xfer: bus:%i cs:%i bitlen:%i len:%i flags:%lx\n",
bus->seq, slave_plat->cs, bitlen, len, flags);
if (bitlen % 8) {
debug("spi_xfer: Non byte aligned SPI transfer\n");
return -1;
}
priv->cs = slave_plat->cs;
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(dev);
while (rx_len > 0) {
/* Write the data into TX FIFO - tx threshold is fifo_depth */
tx_tvl = 0;
while ((tx_tvl < priv->fifo_depth) && tx_len) {
if (tx_buf)
buf = *tx_buf++;
else
buf = 0;
writel(buf, &regs->txdr);
tx_len--;
tx_tvl++;
}
/* Check TX FIFO completion */
ts = get_timer(0);
status = readl(&regs->isr);
while (!(status & ZYNQ_SPI_IXR_TXOW_MASK)) {
if (get_timer(ts) > ZYNQ_SPI_WAIT) {
printf("spi_xfer: Timeout! TX FIFO not full\n");
return -1;
}
status = readl(&regs->isr);
}
/* Read the data from RX FIFO */
status = readl(&regs->isr);
while ((status & ZYNQ_SPI_IXR_RXNEMPTY_MASK) && rx_len) {
buf = readl(&regs->rxdr);
if (rx_buf)
*rx_buf++ = buf;
status = readl(&regs->isr);
rx_len--;
}
}
if (flags & SPI_XFER_END)
spi_cs_deactivate(dev);
return 0;
}
static int zynq_spi_set_speed(struct udevice *bus, uint speed)
{
struct zynq_spi_platdata *plat = bus->plat;
struct zynq_spi_priv *priv = dev_get_priv(bus);
struct zynq_spi_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_SPI_CR_BAUD_MAX) &&
((plat->frequency /
(2 << baud_rate_val)) > speed))
baud_rate_val++;
plat->speed_hz = speed / (2 << baud_rate_val);
}
confr &= ~ZYNQ_SPI_CR_BAUD_MASK;
confr |= (baud_rate_val << ZYNQ_SPI_CR_BAUD_SHIFT);
writel(confr, &regs->cr);
priv->freq = speed;
debug("zynq_spi_set_speed: regs=%p, speed=%d\n",
priv->regs, priv->freq);
return 0;
}
static int zynq_spi_set_mode(struct udevice *bus, uint mode)
{
struct zynq_spi_priv *priv = dev_get_priv(bus);
struct zynq_spi_regs *regs = priv->regs;
uint32_t confr;
/* Set the SPI Clock phase and polarities */
confr = readl(&regs->cr);
confr &= ~(ZYNQ_SPI_CR_CPHA_MASK | ZYNQ_SPI_CR_CPOL_MASK);
if (mode & SPI_CPHA)
confr |= ZYNQ_SPI_CR_CPHA_MASK;
if (mode & SPI_CPOL)
confr |= ZYNQ_SPI_CR_CPOL_MASK;
writel(confr, &regs->cr);
priv->mode = mode;
debug("zynq_spi_set_mode: regs=%p, mode=%d\n", priv->regs, priv->mode);
return 0;
}
static const struct dm_spi_ops zynq_spi_ops = {
.claim_bus = zynq_spi_claim_bus,
.release_bus = zynq_spi_release_bus,
.xfer = zynq_spi_xfer,
.set_speed = zynq_spi_set_speed,
.set_mode = zynq_spi_set_mode,
};
static const struct udevice_id zynq_spi_ids[] = {
{ .compatible = "xlnx,zynq-spi-r1p6" },
{ .compatible = "cdns,spi-r1p6" },
{ }
};
U_BOOT_DRIVER(zynq_spi) = {
.name = "zynq_spi",
.id = UCLASS_SPI,
.of_match = zynq_spi_ids,
.ops = &zynq_spi_ops,
.of_to_plat = zynq_spi_of_to_plat,
.plat_auto = sizeof(struct zynq_spi_platdata),
.priv_auto = sizeof(struct zynq_spi_priv),
.probe = zynq_spi_probe,
};