u-boot/drivers/spi/uniphier_spi.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* uniphier_spi.c - Socionext UniPhier SPI driver
* Copyright 2019 Socionext, Inc.
*/
#include <clk.h>
#include <common.h>
#include <dm.h>
#include <log.h>
#include <time.h>
#include <dm/device_compat.h>
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <spi.h>
#include <wait_bit.h>
DECLARE_GLOBAL_DATA_PTR;
#define SSI_CTL 0x00
#define SSI_CTL_EN BIT(0)
#define SSI_CKS 0x04
#define SSI_CKS_CKRAT_MASK GENMASK(7, 0)
#define SSI_CKS_CKPHS BIT(14)
#define SSI_CKS_CKINIT BIT(13)
#define SSI_CKS_CKDLY BIT(12)
#define SSI_TXWDS 0x08
#define SSI_TXWDS_WDLEN_MASK GENMASK(13, 8)
#define SSI_TXWDS_TDTF_MASK GENMASK(7, 6)
#define SSI_TXWDS_DTLEN_MASK GENMASK(5, 0)
#define SSI_RXWDS 0x0c
#define SSI_RXWDS_RDTF_MASK GENMASK(7, 6)
#define SSI_RXWDS_DTLEN_MASK GENMASK(5, 0)
#define SSI_FPS 0x10
#define SSI_FPS_FSPOL BIT(15)
#define SSI_FPS_FSTRT BIT(14)
#define SSI_SR 0x14
#define SSI_SR_BUSY BIT(7)
#define SSI_SR_TNF BIT(5)
#define SSI_SR_RNE BIT(0)
#define SSI_IE 0x18
#define SSI_IC 0x1c
#define SSI_IC_TCIC BIT(4)
#define SSI_IC_RCIC BIT(3)
#define SSI_IC_RORIC BIT(0)
#define SSI_FC 0x20
#define SSI_FC_TXFFL BIT(12)
#define SSI_FC_TXFTH_MASK GENMASK(11, 8)
#define SSI_FC_RXFFL BIT(4)
#define SSI_FC_RXFTH_MASK GENMASK(3, 0)
#define SSI_XDR 0x24 /* TXDR for write, RXDR for read */
#define SSI_FIFO_DEPTH 8U
#define SSI_REG_TIMEOUT (CONFIG_SYS_HZ / 100) /* 10 ms */
#define SSI_XFER_TIMEOUT (CONFIG_SYS_HZ) /* 1 sec */
#define SSI_CLK 50000000 /* internal I/O clock: 50MHz */
struct uniphier_spi_plat {
void __iomem *base;
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 */
};
struct uniphier_spi_priv {
void __iomem *base;
u8 mode;
u8 fifo_depth;
u8 bits_per_word;
ulong last_transaction_us; /* Time of last transaction end */
};
static void uniphier_spi_enable(struct uniphier_spi_priv *priv, int enable)
{
u32 val;
val = readl(priv->base + SSI_CTL);
if (enable)
val |= SSI_CTL_EN;
else
val &= ~SSI_CTL_EN;
writel(val, priv->base + SSI_CTL);
}
static void uniphier_spi_regdump(struct uniphier_spi_priv *priv)
{
pr_debug("CTL %08x\n", readl(priv->base + SSI_CTL));
pr_debug("CKS %08x\n", readl(priv->base + SSI_CKS));
pr_debug("TXWDS %08x\n", readl(priv->base + SSI_TXWDS));
pr_debug("RXWDS %08x\n", readl(priv->base + SSI_RXWDS));
pr_debug("FPS %08x\n", readl(priv->base + SSI_FPS));
pr_debug("SR %08x\n", readl(priv->base + SSI_SR));
pr_debug("IE %08x\n", readl(priv->base + SSI_IE));
pr_debug("IC %08x\n", readl(priv->base + SSI_IC));
pr_debug("FC %08x\n", readl(priv->base + SSI_FC));
pr_debug("XDR %08x\n", readl(priv->base + SSI_XDR));
}
static void spi_cs_activate(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct uniphier_spi_plat *plat = dev_get_plat(bus);
struct uniphier_spi_priv *priv = dev_get_priv(bus);
ulong delay_us; /* The delay completed so far */
u32 val;
/* If it's too soon to do another transaction, wait */
if (plat->deactivate_delay_us && priv->last_transaction_us) {
delay_us = timer_get_us() - priv->last_transaction_us;
if (delay_us < plat->deactivate_delay_us)
udelay(plat->deactivate_delay_us - delay_us);
}
val = readl(priv->base + SSI_FPS);
if (priv->mode & SPI_CS_HIGH)
val |= SSI_FPS_FSPOL;
else
val &= ~SSI_FPS_FSPOL;
writel(val, priv->base + SSI_FPS);
if (plat->activate_delay_us)
udelay(plat->activate_delay_us);
}
static void spi_cs_deactivate(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct uniphier_spi_plat *plat = dev_get_plat(bus);
struct uniphier_spi_priv *priv = dev_get_priv(bus);
u32 val;
val = readl(priv->base + SSI_FPS);
if (priv->mode & SPI_CS_HIGH)
val &= ~SSI_FPS_FSPOL;
else
val |= SSI_FPS_FSPOL;
writel(val, priv->base + SSI_FPS);
/* 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 uniphier_spi_claim_bus(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct uniphier_spi_priv *priv = dev_get_priv(bus);
u32 val, size;
uniphier_spi_enable(priv, false);
/* disable interrupts */
writel(0, priv->base + SSI_IE);
/* bits_per_word */
size = priv->bits_per_word;
val = readl(priv->base + SSI_TXWDS);
val &= ~(SSI_TXWDS_WDLEN_MASK | SSI_TXWDS_DTLEN_MASK);
val |= FIELD_PREP(SSI_TXWDS_WDLEN_MASK, size);
val |= FIELD_PREP(SSI_TXWDS_DTLEN_MASK, size);
writel(val, priv->base + SSI_TXWDS);
val = readl(priv->base + SSI_RXWDS);
val &= ~SSI_RXWDS_DTLEN_MASK;
val |= FIELD_PREP(SSI_RXWDS_DTLEN_MASK, size);
writel(val, priv->base + SSI_RXWDS);
/* reset FIFOs */
val = SSI_FC_TXFFL | SSI_FC_RXFFL;
writel(val, priv->base + SSI_FC);
/* FIFO threthold */
val = readl(priv->base + SSI_FC);
val &= ~(SSI_FC_TXFTH_MASK | SSI_FC_RXFTH_MASK);
val |= FIELD_PREP(SSI_FC_TXFTH_MASK, priv->fifo_depth);
val |= FIELD_PREP(SSI_FC_RXFTH_MASK, priv->fifo_depth);
writel(val, priv->base + SSI_FC);
/* clear interrupts */
writel(SSI_IC_TCIC | SSI_IC_RCIC | SSI_IC_RORIC,
priv->base + SSI_IC);
uniphier_spi_enable(priv, true);
return 0;
}
static int uniphier_spi_release_bus(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct uniphier_spi_priv *priv = dev_get_priv(bus);
uniphier_spi_enable(priv, false);
return 0;
}
static int uniphier_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = dev->parent;
struct uniphier_spi_priv *priv = dev_get_priv(bus);
const u8 *tx_buf = dout;
u8 *rx_buf = din, buf;
u32 len = bitlen / 8;
u32 tx_len, rx_len;
u32 ts, status;
int ret = 0;
if (bitlen % 8) {
dev_err(dev, "Non byte aligned SPI transfer\n");
return -EINVAL;
}
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(dev);
uniphier_spi_enable(priv, true);
ts = get_timer(0);
tx_len = len;
rx_len = len;
uniphier_spi_regdump(priv);
while (tx_len || rx_len) {
ret = wait_for_bit_le32(priv->base + SSI_SR, SSI_SR_BUSY, false,
SSI_REG_TIMEOUT * 1000, false);
if (ret) {
if (ret == -ETIMEDOUT)
dev_err(dev, "access timeout\n");
break;
}
status = readl(priv->base + SSI_SR);
/* write the data into TX */
if (tx_len && (status & SSI_SR_TNF)) {
buf = tx_buf ? *tx_buf++ : 0;
writel(buf, priv->base + SSI_XDR);
tx_len--;
}
/* read the data from RX */
if (rx_len && (status & SSI_SR_RNE)) {
buf = readl(priv->base + SSI_XDR);
if (rx_buf)
*rx_buf++ = buf;
rx_len--;
}
if (get_timer(ts) >= SSI_XFER_TIMEOUT) {
dev_err(dev, "transfer timeout\n");
ret = -ETIMEDOUT;
break;
}
}
if (flags & SPI_XFER_END)
spi_cs_deactivate(dev);
uniphier_spi_enable(priv, false);
return ret;
}
static int uniphier_spi_set_speed(struct udevice *bus, uint speed)
{
struct uniphier_spi_plat *plat = dev_get_plat(bus);
struct uniphier_spi_priv *priv = dev_get_priv(bus);
u32 val, ckdiv;
if (speed > plat->frequency)
speed = plat->frequency;
/* baudrate */
ckdiv = DIV_ROUND_UP(SSI_CLK, speed);
ckdiv = round_up(ckdiv, 2);
val = readl(priv->base + SSI_CKS);
val &= ~SSI_CKS_CKRAT_MASK;
val |= ckdiv & SSI_CKS_CKRAT_MASK;
writel(val, priv->base + SSI_CKS);
return 0;
}
static int uniphier_spi_set_mode(struct udevice *bus, uint mode)
{
struct uniphier_spi_priv *priv = dev_get_priv(bus);
u32 val1, val2;
/*
* clock setting
* CKPHS capture timing. 0:rising edge, 1:falling edge
* CKINIT clock initial level. 0:low, 1:high
* CKDLY clock delay. 0:no delay, 1:delay depending on FSTRT
* (FSTRT=0: 1 clock, FSTRT=1: 0.5 clock)
*
* frame setting
* FSPOL frame signal porarity. 0: low, 1: high
* FSTRT start frame timing
* 0: rising edge of clock, 1: falling edge of clock
*/
val1 = readl(priv->base + SSI_CKS);
val2 = readl(priv->base + SSI_FPS);
switch (mode & (SPI_CPOL | SPI_CPHA)) {
case SPI_MODE_0:
/* CKPHS=1, CKINIT=0, CKDLY=1, FSTRT=0 */
val1 |= SSI_CKS_CKPHS | SSI_CKS_CKDLY;
val1 &= ~SSI_CKS_CKINIT;
val2 &= ~SSI_FPS_FSTRT;
break;
case SPI_MODE_1:
/* CKPHS=0, CKINIT=0, CKDLY=0, FSTRT=1 */
val1 &= ~(SSI_CKS_CKPHS | SSI_CKS_CKINIT | SSI_CKS_CKDLY);
val2 |= SSI_FPS_FSTRT;
break;
case SPI_MODE_2:
/* CKPHS=0, CKINIT=1, CKDLY=1, FSTRT=1 */
val1 |= SSI_CKS_CKINIT | SSI_CKS_CKDLY;
val1 &= ~SSI_CKS_CKPHS;
val2 |= SSI_FPS_FSTRT;
break;
case SPI_MODE_3:
/* CKPHS=1, CKINIT=1, CKDLY=0, FSTRT=0 */
val1 |= SSI_CKS_CKPHS | SSI_CKS_CKINIT;
val1 &= ~SSI_CKS_CKDLY;
val2 &= ~SSI_FPS_FSTRT;
break;
}
writel(val1, priv->base + SSI_CKS);
writel(val2, priv->base + SSI_FPS);
/* format */
val1 = readl(priv->base + SSI_TXWDS);
val2 = readl(priv->base + SSI_RXWDS);
if (mode & SPI_LSB_FIRST) {
val1 |= FIELD_PREP(SSI_TXWDS_TDTF_MASK, 1);
val2 |= FIELD_PREP(SSI_RXWDS_RDTF_MASK, 1);
}
writel(val1, priv->base + SSI_TXWDS);
writel(val2, priv->base + SSI_RXWDS);
priv->mode = mode;
return 0;
}
static int uniphier_spi_of_to_plat(struct udevice *bus)
{
struct uniphier_spi_plat *plat = dev_get_plat(bus);
const void *blob = gd->fdt_blob;
int node = dev_of_offset(bus);
plat->base = dev_read_addr_ptr(bus);
plat->frequency =
fdtdec_get_int(blob, node, "spi-max-frequency", 12500000);
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);
plat->speed_hz = plat->frequency / 2;
return 0;
}
static int uniphier_spi_probe(struct udevice *bus)
{
struct uniphier_spi_plat *plat = dev_get_plat(bus);
struct uniphier_spi_priv *priv = dev_get_priv(bus);
priv->base = plat->base;
priv->fifo_depth = SSI_FIFO_DEPTH;
priv->bits_per_word = 8;
return 0;
}
static const struct dm_spi_ops uniphier_spi_ops = {
.claim_bus = uniphier_spi_claim_bus,
.release_bus = uniphier_spi_release_bus,
.xfer = uniphier_spi_xfer,
.set_speed = uniphier_spi_set_speed,
.set_mode = uniphier_spi_set_mode,
};
static const struct udevice_id uniphier_spi_ids[] = {
{ .compatible = "socionext,uniphier-scssi" },
{ /* Sentinel */ }
};
U_BOOT_DRIVER(uniphier_spi) = {
.name = "uniphier_spi",
.id = UCLASS_SPI,
.of_match = uniphier_spi_ids,
.ops = &uniphier_spi_ops,
.of_to_plat = uniphier_spi_of_to_plat,
.plat_auto = sizeof(struct uniphier_spi_plat),
.priv_auto = sizeof(struct uniphier_spi_priv),
.probe = uniphier_spi_probe,
};