u-boot/drivers/spi/kirkwood_spi.c
Grzegorz Jaszczyk 9c84159ce1 spi: kirkwood: prevent limiting speed to 0
After commit 1fe929ed497bcc8975be8d37383ebafd22b99dd2
("spi: kirkwood: prevent configuring speed exceeding max controller freq")
the spi frequency could be set to 0 on platform where spi-max-frequency
is not defined (e.g. on armada-388-gp). Prevent limiting speed in
mentioned cases.

Signed-off-by: Grzegorz Jaszczyk <jaz@semihalf.com>
Tested-by: Kostya Porotchkin <kostap@marvell.com>
Reviewed-by: Marcin Wojtas <marcin@marvell.com>
Reviewed-by: Kostya Porotchkin <kostap@marvell.com>
Signed-off-by: Stefan Roese <sr@denx.de>
2021-05-16 06:48:45 +02:00

359 lines
8.8 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2009
* Marvell Semiconductor <www.marvell.com>
* Written-by: Prafulla Wadaskar <prafulla@marvell.com>
*
* Derived from drivers/spi/mpc8xxx_spi.c
*/
#include <common.h>
#include <dm.h>
#include <log.h>
#include <malloc.h>
#include <spi.h>
#include <asm/io.h>
#include <asm/arch/soc.h>
#ifdef CONFIG_ARCH_KIRKWOOD
#include <asm/arch/mpp.h>
#endif
#include <asm/arch-mvebu/spi.h>
struct mvebu_spi_dev {
bool is_errata_50mhz_ac;
};
struct mvebu_spi_plat {
struct kwspi_registers *spireg;
bool is_errata_50mhz_ac;
};
struct mvebu_spi_priv {
struct kwspi_registers *spireg;
};
static void _spi_cs_activate(struct kwspi_registers *reg)
{
setbits_le32(&reg->ctrl, KWSPI_CSN_ACT);
}
static void _spi_cs_deactivate(struct kwspi_registers *reg)
{
clrbits_le32(&reg->ctrl, KWSPI_CSN_ACT);
}
static int _spi_xfer(struct kwspi_registers *reg, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
unsigned int tmpdout, tmpdin;
int tm, isread = 0;
debug("spi_xfer: dout %p din %p bitlen %u\n", dout, din, bitlen);
if (flags & SPI_XFER_BEGIN)
_spi_cs_activate(reg);
/*
* handle data in 8-bit chunks
* TBD: 2byte xfer mode to be enabled
*/
clrsetbits_le32(&reg->cfg, KWSPI_XFERLEN_MASK, KWSPI_XFERLEN_1BYTE);
while (bitlen > 4) {
debug("loopstart bitlen %d\n", bitlen);
tmpdout = 0;
/* Shift data so it's msb-justified */
if (dout)
tmpdout = *(u32 *)dout & 0xff;
clrbits_le32(&reg->irq_cause, KWSPI_SMEMRDIRQ);
writel(tmpdout, &reg->dout); /* Write the data out */
debug("*** spi_xfer: ... %08x written, bitlen %d\n",
tmpdout, bitlen);
/*
* Wait for SPI transmit to get out
* or time out (1 second = 1000 ms)
* The NE event must be read and cleared first
*/
for (tm = 0, isread = 0; tm < KWSPI_TIMEOUT; ++tm) {
if (readl(&reg->irq_cause) & KWSPI_SMEMRDIRQ) {
isread = 1;
tmpdin = readl(&reg->din);
debug("spi_xfer: din %p..%08x read\n",
din, tmpdin);
if (din) {
*((u8 *)din) = (u8)tmpdin;
din += 1;
}
if (dout)
dout += 1;
bitlen -= 8;
}
if (isread)
break;
}
if (tm >= KWSPI_TIMEOUT)
printf("*** spi_xfer: Time out during SPI transfer\n");
debug("loopend bitlen %d\n", bitlen);
}
if (flags & SPI_XFER_END)
_spi_cs_deactivate(reg);
return 0;
}
static int mvebu_spi_set_speed(struct udevice *bus, uint hz)
{
struct mvebu_spi_plat *plat = dev_get_plat(bus);
struct dm_spi_bus *spi = dev_get_uclass_priv(bus);
struct kwspi_registers *reg = plat->spireg;
u32 data, divider;
unsigned int spr, sppr;
if (spi->max_hz && (hz > spi->max_hz)) {
debug("%s: limit speed to the max_hz of the bus %d\n",
__func__, spi->max_hz);
hz = spi->max_hz;
}
/*
* Calculate spi clock prescaller using max_hz.
* SPPR is SPI Baud Rate Pre-selection, it holds bits 5 and 7:6 in
* SPI Interface Configuration Register;
* SPR is SPI Baud Rate Selection, it holds bits 3:0 in SPI Interface
* Configuration Register.
* The SPR together with the SPPR define the SPI CLK frequency as
* follows:
* SPI actual frequency = core_clk / (SPR * (2 ^ SPPR))
*/
divider = DIV_ROUND_UP(CONFIG_SYS_TCLK, hz);
if (divider < 16) {
/* This is the easy case, divider is less than 16 */
spr = divider;
sppr = 0;
} else {
unsigned int two_pow_sppr;
/*
* Find the highest bit set in divider. This and the
* three next bits define SPR (apart from rounding).
* SPPR is then the number of zero bits that must be
* appended:
*/
sppr = fls(divider) - 4;
/*
* As SPR only has 4 bits, we have to round divider up
* to the next multiple of 2 ** sppr.
*/
two_pow_sppr = 1 << sppr;
divider = (divider + two_pow_sppr - 1) & -two_pow_sppr;
/*
* recalculate sppr as rounding up divider might have
* increased it enough to change the position of the
* highest set bit. In this case the bit that now
* doesn't make it into SPR is 0, so there is no need to
* round again.
*/
sppr = fls(divider) - 4;
spr = divider >> sppr;
/*
* Now do range checking. SPR is constructed to have a
* width of 4 bits, so this is fine for sure. So we
* still need to check for sppr to fit into 3 bits:
*/
if (sppr > 7)
return -EINVAL;
}
data = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | spr;
/* program spi clock prescaler using max_hz */
writel(KWSPI_ADRLEN_3BYTE | data, &reg->cfg);
debug("data = 0x%08x\n", data);
return 0;
}
static void mvebu_spi_50mhz_ac_timing_erratum(struct udevice *bus, uint mode)
{
struct mvebu_spi_plat *plat = dev_get_plat(bus);
struct kwspi_registers *reg = plat->spireg;
u32 data;
/*
* Erratum description: (Erratum NO. FE-9144572) The device
* SPI interface supports frequencies of up to 50 MHz.
* However, due to this erratum, when the device core clock is
* 250 MHz and the SPI interfaces is configured for 50MHz SPI
* clock and CPOL=CPHA=1 there might occur data corruption on
* reads from the SPI device.
* Erratum Workaround:
* Work in one of the following configurations:
* 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
* Register".
* 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
* Register" before setting the interface.
*/
data = readl(&reg->timing1);
data &= ~KW_SPI_TMISO_SAMPLE_MASK;
if (CONFIG_SYS_TCLK == 250000000 &&
mode & SPI_CPOL &&
mode & SPI_CPHA)
data |= KW_SPI_TMISO_SAMPLE_2;
else
data |= KW_SPI_TMISO_SAMPLE_1;
writel(data, &reg->timing1);
}
static int mvebu_spi_set_mode(struct udevice *bus, uint mode)
{
struct mvebu_spi_plat *plat = dev_get_plat(bus);
struct kwspi_registers *reg = plat->spireg;
u32 data = readl(&reg->cfg);
data &= ~(KWSPI_CPHA | KWSPI_CPOL | KWSPI_RXLSBF | KWSPI_TXLSBF);
if (mode & SPI_CPHA)
data |= KWSPI_CPHA;
if (mode & SPI_CPOL)
data |= KWSPI_CPOL;
if (mode & SPI_LSB_FIRST)
data |= (KWSPI_RXLSBF | KWSPI_TXLSBF);
writel(data, &reg->cfg);
if (plat->is_errata_50mhz_ac)
mvebu_spi_50mhz_ac_timing_erratum(bus, mode);
return 0;
}
static int mvebu_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = dev->parent;
struct mvebu_spi_plat *plat = dev_get_plat(bus);
return _spi_xfer(plat->spireg, bitlen, dout, din, flags);
}
__attribute__((weak)) int mvebu_board_spi_claim_bus(struct udevice *dev)
{
return 0;
}
static int mvebu_spi_claim_bus(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct mvebu_spi_plat *plat = dev_get_plat(bus);
/* Configure the chip-select in the CTRL register */
clrsetbits_le32(&plat->spireg->ctrl,
KWSPI_CS_MASK << KWSPI_CS_SHIFT,
spi_chip_select(dev) << KWSPI_CS_SHIFT);
return mvebu_board_spi_claim_bus(dev);
}
__attribute__((weak)) int mvebu_board_spi_release_bus(struct udevice *dev)
{
return 0;
}
static int mvebu_spi_release_bus(struct udevice *dev)
{
return mvebu_board_spi_release_bus(dev);
}
static int mvebu_spi_probe(struct udevice *bus)
{
struct mvebu_spi_plat *plat = dev_get_plat(bus);
struct kwspi_registers *reg = plat->spireg;
writel(KWSPI_SMEMRDY, &reg->ctrl);
writel(KWSPI_SMEMRDIRQ, &reg->irq_cause);
writel(KWSPI_IRQMASK, &reg->irq_mask);
return 0;
}
static int mvebu_spi_of_to_plat(struct udevice *bus)
{
struct mvebu_spi_plat *plat = dev_get_plat(bus);
const struct mvebu_spi_dev *drvdata =
(struct mvebu_spi_dev *)dev_get_driver_data(bus);
plat->spireg = dev_read_addr_ptr(bus);
plat->is_errata_50mhz_ac = drvdata->is_errata_50mhz_ac;
return 0;
}
static const struct dm_spi_ops mvebu_spi_ops = {
.claim_bus = mvebu_spi_claim_bus,
.release_bus = mvebu_spi_release_bus,
.xfer = mvebu_spi_xfer,
.set_speed = mvebu_spi_set_speed,
.set_mode = mvebu_spi_set_mode,
/*
* cs_info is not needed, since we require all chip selects to be
* in the device tree explicitly
*/
};
static const struct mvebu_spi_dev armada_spi_dev_data = {
.is_errata_50mhz_ac = false,
};
static const struct mvebu_spi_dev armada_xp_spi_dev_data = {
.is_errata_50mhz_ac = false,
};
static const struct mvebu_spi_dev armada_375_spi_dev_data = {
.is_errata_50mhz_ac = false,
};
static const struct mvebu_spi_dev armada_380_spi_dev_data = {
.is_errata_50mhz_ac = true,
};
static const struct udevice_id mvebu_spi_ids[] = {
{
.compatible = "marvell,orion-spi",
.data = (ulong)&armada_spi_dev_data,
},
{
.compatible = "marvell,armada-375-spi",
.data = (ulong)&armada_375_spi_dev_data
},
{
.compatible = "marvell,armada-380-spi",
.data = (ulong)&armada_380_spi_dev_data
},
{
.compatible = "marvell,armada-xp-spi",
.data = (ulong)&armada_xp_spi_dev_data
},
{ }
};
U_BOOT_DRIVER(mvebu_spi) = {
.name = "mvebu_spi",
.id = UCLASS_SPI,
.of_match = mvebu_spi_ids,
.ops = &mvebu_spi_ops,
.of_to_plat = mvebu_spi_of_to_plat,
.plat_auto = sizeof(struct mvebu_spi_plat),
.priv_auto = sizeof(struct mvebu_spi_priv),
.probe = mvebu_spi_probe,
};