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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2010-2013 NVIDIA Corporation
* With help from the mpc8xxx SPI driver
* With more help from omap3_spi SPI driver
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <log.h>
#include <time.h>
#include <asm/io.h>
#include <asm/gpio.h>
#include <asm/arch/clock.h>
#include <asm/arch/pinmux.h>
#include <asm/arch-tegra/clk_rst.h>
#include <spi.h>
#include <fdtdec.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include "tegra_spi.h"
DECLARE_GLOBAL_DATA_PTR;
#define SPI_CMD_GO BIT(30)
#define SPI_CMD_ACTIVE_SCLK_SHIFT 26
#define SPI_CMD_ACTIVE_SCLK_MASK (3 << SPI_CMD_ACTIVE_SCLK_SHIFT)
#define SPI_CMD_CK_SDA BIT(21)
#define SPI_CMD_ACTIVE_SDA_SHIFT 18
#define SPI_CMD_ACTIVE_SDA_MASK (3 << SPI_CMD_ACTIVE_SDA_SHIFT)
#define SPI_CMD_CS_POL BIT(16)
#define SPI_CMD_TXEN BIT(15)
#define SPI_CMD_RXEN BIT(14)
#define SPI_CMD_CS_VAL BIT(13)
#define SPI_CMD_CS_SOFT BIT(12)
#define SPI_CMD_CS_DELAY BIT(9)
#define SPI_CMD_CS3_EN BIT(8)
#define SPI_CMD_CS2_EN BIT(7)
#define SPI_CMD_CS1_EN BIT(6)
#define SPI_CMD_CS0_EN BIT(5)
#define SPI_CMD_BIT_LENGTH BIT(4)
#define SPI_CMD_BIT_LENGTH_MASK GENMASK(4, 0)
#define SPI_STAT_BSY BIT(31)
#define SPI_STAT_RDY BIT(30)
#define SPI_STAT_RXF_FLUSH BIT(29)
#define SPI_STAT_TXF_FLUSH BIT(28)
#define SPI_STAT_RXF_UNR BIT(27)
#define SPI_STAT_TXF_OVF BIT(26)
#define SPI_STAT_RXF_EMPTY BIT(25)
#define SPI_STAT_RXF_FULL BIT(24)
#define SPI_STAT_TXF_EMPTY BIT(23)
#define SPI_STAT_TXF_FULL BIT(22)
#define SPI_STAT_SEL_TXRX_N BIT(16)
#define SPI_STAT_CUR_BLKCNT BIT(15)
#define SPI_TIMEOUT 1000
#define TEGRA_SPI_MAX_FREQ 52000000
struct spi_regs {
u32 command; /* SPI_COMMAND_0 register */
u32 status; /* SPI_STATUS_0 register */
u32 rx_cmp; /* SPI_RX_CMP_0 register */
u32 dma_ctl; /* SPI_DMA_CTL_0 register */
u32 tx_fifo; /* SPI_TX_FIFO_0 register */
u32 rsvd[3]; /* offsets 0x14 to 0x1F reserved */
u32 rx_fifo; /* SPI_RX_FIFO_0 register */
};
struct tegra20_sflash_priv {
struct spi_regs *regs;
unsigned int freq;
unsigned int mode;
int periph_id;
int valid;
int last_transaction_us;
};
int tegra20_sflash_cs_info(struct udevice *bus, unsigned int cs,
struct spi_cs_info *info)
{
/* Tegra20 SPI-Flash - only 1 device ('bus/cs') */
if (cs != 0)
return -EINVAL;
else
return 0;
}
static int tegra20_sflash_of_to_plat(struct udevice *bus)
{
struct tegra_spi_platdata *plat = bus->plat;
const void *blob = gd->fdt_blob;
int node = dev_of_offset(bus);
plat->base = dev_read_addr(bus);
plat->periph_id = clock_decode_periph_id(bus);
if (plat->periph_id == PERIPH_ID_NONE) {
debug("%s: could not decode periph id %d\n", __func__,
plat->periph_id);
return -FDT_ERR_NOTFOUND;
}
/* Use 500KHz as a suitable default */
plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
500000);
plat->deactivate_delay_us = fdtdec_get_int(blob, node,
"spi-deactivate-delay", 0);
debug("%s: base=%#08lx, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n",
__func__, plat->base, plat->periph_id, plat->frequency,
plat->deactivate_delay_us);
return 0;
}
static int tegra20_sflash_probe(struct udevice *bus)
{
struct tegra_spi_platdata *plat = dev_get_plat(bus);
struct tegra20_sflash_priv *priv = dev_get_priv(bus);
priv->regs = (struct spi_regs *)plat->base;
priv->last_transaction_us = timer_get_us();
priv->freq = plat->frequency;
priv->periph_id = plat->periph_id;
/* Change SPI clock to correct frequency, PLLP_OUT0 source */
clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH,
priv->freq);
return 0;
}
static int tegra20_sflash_claim_bus(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct tegra20_sflash_priv *priv = dev_get_priv(bus);
struct spi_regs *regs = priv->regs;
u32 reg;
/* Change SPI clock to correct frequency, PLLP_OUT0 source */
clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH,
priv->freq);
/* Clear stale status here */
reg = SPI_STAT_RDY | SPI_STAT_RXF_FLUSH | SPI_STAT_TXF_FLUSH | \
SPI_STAT_RXF_UNR | SPI_STAT_TXF_OVF;
writel(reg, ®s->status);
debug("%s: STATUS = %08x\n", __func__, readl(®s->status));
/*
* Use sw-controlled CS, so we can clock in data after ReadID, etc.
*/
reg = (priv->mode & 1) << SPI_CMD_ACTIVE_SDA_SHIFT;
if (priv->mode & 2)
reg |= 1 << SPI_CMD_ACTIVE_SCLK_SHIFT;
clrsetbits_le32(®s->command, SPI_CMD_ACTIVE_SCLK_MASK |
SPI_CMD_ACTIVE_SDA_MASK, SPI_CMD_CS_SOFT | reg);
debug("%s: COMMAND = %08x\n", __func__, readl(®s->command));
/*
* SPI pins on Tegra20 are muxed - change pinmux later due to UART
* issue.
*/
pinmux_set_func(PMUX_PINGRP_GMD, PMUX_FUNC_SFLASH);
pinmux_tristate_disable(PMUX_PINGRP_LSPI);
pinmux_set_func(PMUX_PINGRP_GMC, PMUX_FUNC_SFLASH);
return 0;
}
static void spi_cs_activate(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct tegra_spi_platdata *pdata = dev_get_plat(bus);
struct tegra20_sflash_priv *priv = dev_get_priv(bus);
/* If it's too soon to do another transaction, wait */
if (pdata->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 < pdata->deactivate_delay_us)
udelay(pdata->deactivate_delay_us - delay_us);
}
/* CS is negated on Tegra, so drive a 1 to get a 0 */
setbits_le32(&priv->regs->command, SPI_CMD_CS_VAL);
}
static void spi_cs_deactivate(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct tegra_spi_platdata *pdata = dev_get_plat(bus);
struct tegra20_sflash_priv *priv = dev_get_priv(bus);
/* CS is negated on Tegra, so drive a 0 to get a 1 */
clrbits_le32(&priv->regs->command, SPI_CMD_CS_VAL);
/* Remember time of this transaction so we can honour the bus delay */
if (pdata->deactivate_delay_us)
priv->last_transaction_us = timer_get_us();
}
static int tegra20_sflash_xfer(struct udevice *dev, unsigned int bitlen,
const void *data_out, void *data_in,
unsigned long flags)
{
struct udevice *bus = dev->parent;
struct tegra20_sflash_priv *priv = dev_get_priv(bus);
struct spi_regs *regs = priv->regs;
u32 reg, tmpdout, tmpdin = 0;
const u8 *dout = data_out;
u8 *din = data_in;
int num_bytes;
int ret;
debug("%s: slave %u:%u dout %p din %p bitlen %u\n",
__func__, bus->seq, spi_chip_select(dev), dout, din, bitlen);
if (bitlen % 8)
return -1;
num_bytes = bitlen / 8;
ret = 0;
reg = readl(®s->status);
writel(reg, ®s->status); /* Clear all SPI events via R/W */
debug("spi_xfer entry: STATUS = %08x\n", reg);
reg = readl(®s->command);
reg |= SPI_CMD_TXEN | SPI_CMD_RXEN;
writel(reg, ®s->command);
debug("spi_xfer: COMMAND = %08x\n", readl(®s->command));
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(dev);
/* handle data in 32-bit chunks */
while (num_bytes > 0) {
int bytes;
int is_read = 0;
int tm, i;
tmpdout = 0;
bytes = (num_bytes > 4) ? 4 : num_bytes;
if (dout != NULL) {
for (i = 0; i < bytes; ++i)
tmpdout = (tmpdout << 8) | dout[i];
}
num_bytes -= bytes;
if (dout)
dout += bytes;
clrsetbits_le32(®s->command, SPI_CMD_BIT_LENGTH_MASK,
bytes * 8 - 1);
writel(tmpdout, ®s->tx_fifo);
setbits_le32(®s->command, SPI_CMD_GO);
/*
* Wait for SPI transmit FIFO to empty, or to time out.
* The RX FIFO status will be read and cleared last
*/
for (tm = 0, is_read = 0; tm < SPI_TIMEOUT; ++tm) {
u32 status;
status = readl(®s->status);
/* We can exit when we've had both RX and TX activity */
if (is_read && (status & SPI_STAT_TXF_EMPTY))
break;
if ((status & (SPI_STAT_BSY | SPI_STAT_RDY)) !=
SPI_STAT_RDY)
tm++;
else if (!(status & SPI_STAT_RXF_EMPTY)) {
tmpdin = readl(®s->rx_fifo);
is_read = 1;
/* swap bytes read in */
if (din != NULL) {
for (i = bytes - 1; i >= 0; --i) {
din[i] = tmpdin & 0xff;
tmpdin >>= 8;
}
din += bytes;
}
}
}
if (tm >= SPI_TIMEOUT)
ret = tm;
/* clear ACK RDY, etc. bits */
writel(readl(®s->status), ®s->status);
}
if (flags & SPI_XFER_END)
spi_cs_deactivate(dev);
debug("spi_xfer: transfer ended. Value=%08x, status = %08x\n",
tmpdin, readl(®s->status));
if (ret) {
printf("spi_xfer: timeout during SPI transfer, tm %d\n", ret);
return -1;
}
return 0;
}
static int tegra20_sflash_set_speed(struct udevice *bus, uint speed)
{
struct tegra_spi_platdata *plat = bus->plat;
struct tegra20_sflash_priv *priv = dev_get_priv(bus);
if (speed > plat->frequency)
speed = plat->frequency;
priv->freq = speed;
debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);
return 0;
}
static int tegra20_sflash_set_mode(struct udevice *bus, uint mode)
{
struct tegra20_sflash_priv *priv = dev_get_priv(bus);
priv->mode = mode;
debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
return 0;
}
static const struct dm_spi_ops tegra20_sflash_ops = {
.claim_bus = tegra20_sflash_claim_bus,
.xfer = tegra20_sflash_xfer,
.set_speed = tegra20_sflash_set_speed,
.set_mode = tegra20_sflash_set_mode,
.cs_info = tegra20_sflash_cs_info,
};
static const struct udevice_id tegra20_sflash_ids[] = {
{ .compatible = "nvidia,tegra20-sflash" },
{ }
};
U_BOOT_DRIVER(tegra20_sflash) = {
.name = "tegra20_sflash",
.id = UCLASS_SPI,
.of_match = tegra20_sflash_ids,
.ops = &tegra20_sflash_ops,
.of_to_plat = tegra20_sflash_of_to_plat,
.plat_auto = sizeof(struct tegra_spi_platdata),
.priv_auto = sizeof(struct tegra20_sflash_priv),
.probe = tegra20_sflash_probe,
};
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