u-boot/drivers/spi/mpc8xxx_spi.c
Simon Glass cd93d625fd common: Drop linux/bitops.h from common header
Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-05-18 21:19:23 -04:00

287 lines
6.9 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2006 Ben Warren, Qstreams Networks Inc.
* With help from the common/soft_spi and arch/powerpc/cpu/mpc8260 drivers
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <errno.h>
#include <log.h>
#include <malloc.h>
#include <spi.h>
#include <asm/mpc8xxx_spi.h>
#include <asm-generic/gpio.h>
#include <dm/device_compat.h>
#include <linux/bitops.h>
#include <linux/delay.h>
enum {
SPI_EV_NE = BIT(31 - 22), /* Receiver Not Empty */
SPI_EV_NF = BIT(31 - 23), /* Transmitter Not Full */
};
enum {
SPI_MODE_LOOP = BIT(31 - 1), /* Loopback mode */
SPI_MODE_CI = BIT(31 - 2), /* Clock invert */
SPI_MODE_CP = BIT(31 - 3), /* Clock phase */
SPI_MODE_DIV16 = BIT(31 - 4), /* Divide clock source by 16 */
SPI_MODE_REV = BIT(31 - 5), /* Reverse mode - MSB first */
SPI_MODE_MS = BIT(31 - 6), /* Always master */
SPI_MODE_EN = BIT(31 - 7), /* Enable interface */
SPI_MODE_LEN_MASK = 0xf00000,
SPI_MODE_LEN_SHIFT = 20,
SPI_MODE_PM_SHIFT = 16,
SPI_MODE_PM_MASK = 0xf0000,
SPI_COM_LST = BIT(31 - 9),
};
struct mpc8xxx_priv {
spi8xxx_t *spi;
struct gpio_desc gpios[16];
int cs_count;
ulong clk_rate;
};
#define SPI_TIMEOUT 1000
static int mpc8xxx_spi_ofdata_to_platdata(struct udevice *dev)
{
struct mpc8xxx_priv *priv = dev_get_priv(dev);
struct clk clk;
int ret;
priv->spi = (spi8xxx_t *)dev_read_addr(dev);
ret = gpio_request_list_by_name(dev, "gpios", priv->gpios,
ARRAY_SIZE(priv->gpios), GPIOD_IS_OUT | GPIOD_ACTIVE_LOW);
if (ret < 0)
return -EINVAL;
priv->cs_count = ret;
ret = clk_get_by_index(dev, 0, &clk);
if (ret) {
dev_err(dev, "%s: clock not defined\n", __func__);
return ret;
}
priv->clk_rate = clk_get_rate(&clk);
if (!priv->clk_rate) {
dev_err(dev, "%s: failed to get clock rate\n", __func__);
return -EINVAL;
}
return 0;
}
static int mpc8xxx_spi_probe(struct udevice *dev)
{
struct mpc8xxx_priv *priv = dev_get_priv(dev);
spi8xxx_t *spi = priv->spi;
/*
* SPI pins on the MPC83xx are not muxed, so all we do is initialize
* some registers
*/
out_be32(&priv->spi->mode, SPI_MODE_REV | SPI_MODE_MS);
/* set len to 8 bits */
setbits_be32(&spi->mode, (8 - 1) << SPI_MODE_LEN_SHIFT);
setbits_be32(&spi->mode, SPI_MODE_EN);
/* Clear all SPI events */
setbits_be32(&priv->spi->event, 0xffffffff);
/* Mask all SPI interrupts */
clrbits_be32(&priv->spi->mask, 0xffffffff);
/* LST bit doesn't do anything, so disregard */
out_be32(&priv->spi->com, 0);
return 0;
}
static void mpc8xxx_spi_cs_activate(struct udevice *dev)
{
struct mpc8xxx_priv *priv = dev_get_priv(dev->parent);
struct dm_spi_slave_platdata *platdata = dev_get_parent_platdata(dev);
dm_gpio_set_dir_flags(&priv->gpios[platdata->cs], GPIOD_IS_OUT);
dm_gpio_set_value(&priv->gpios[platdata->cs], 0);
}
static void mpc8xxx_spi_cs_deactivate(struct udevice *dev)
{
struct mpc8xxx_priv *priv = dev_get_priv(dev->parent);
struct dm_spi_slave_platdata *platdata = dev_get_parent_platdata(dev);
dm_gpio_set_dir_flags(&priv->gpios[platdata->cs], GPIOD_IS_OUT);
dm_gpio_set_value(&priv->gpios[platdata->cs], 1);
}
static int mpc8xxx_spi_xfer(struct udevice *dev, uint bitlen,
const void *dout, void *din, ulong flags)
{
struct udevice *bus = dev->parent;
struct mpc8xxx_priv *priv = dev_get_priv(bus);
spi8xxx_t *spi = priv->spi;
struct dm_spi_slave_platdata *platdata = dev_get_parent_platdata(dev);
u32 tmpdin = 0, tmpdout = 0, n;
const u8 *cout = dout;
u8 *cin = din;
debug("%s: slave %s:%u dout %08X din %08X bitlen %u\n", __func__,
bus->name, platdata->cs, (uint)dout, (uint)din, bitlen);
if (platdata->cs >= priv->cs_count) {
dev_err(dev, "chip select index %d too large (cs_count=%d)\n",
platdata->cs, priv->cs_count);
return -EINVAL;
}
if (bitlen % 8) {
printf("*** spi_xfer: bitlen must be multiple of 8\n");
return -ENOTSUPP;
}
if (flags & SPI_XFER_BEGIN)
mpc8xxx_spi_cs_activate(dev);
/* Clear all SPI events */
setbits_be32(&spi->event, 0xffffffff);
n = bitlen / 8;
/* Handle data in 8-bit chunks */
while (n--) {
ulong start;
if (cout)
tmpdout = *cout++;
/* Write the data out */
out_be32(&spi->tx, tmpdout);
debug("*** %s: ... %08x written\n", __func__, tmpdout);
/*
* Wait for SPI transmit to get out
* or time out (1 second = 1000 ms)
* The NE event must be read and cleared first
*/
start = get_timer(0);
do {
u32 event = in_be32(&spi->event);
bool have_ne = event & SPI_EV_NE;
bool have_nf = event & SPI_EV_NF;
if (!have_ne)
continue;
tmpdin = in_be32(&spi->rx);
setbits_be32(&spi->event, SPI_EV_NE);
if (cin)
*cin++ = tmpdin;
/*
* Only bail when we've had both NE and NF events.
* This will cause timeouts on RO devices, so maybe
* in the future put an arbitrary delay after writing
* the device. Arbitrary delays suck, though...
*/
if (have_nf)
break;
mdelay(1);
} while (get_timer(start) < SPI_TIMEOUT);
if (get_timer(start) >= SPI_TIMEOUT) {
debug("*** %s: Time out during SPI transfer\n",
__func__);
return -ETIMEDOUT;
}
debug("*** %s: transfer ended. Value=%08x\n", __func__, tmpdin);
}
if (flags & SPI_XFER_END)
mpc8xxx_spi_cs_deactivate(dev);
return 0;
}
static int mpc8xxx_spi_set_speed(struct udevice *dev, uint speed)
{
struct mpc8xxx_priv *priv = dev_get_priv(dev);
spi8xxx_t *spi = priv->spi;
u32 bits, mask, div16, pm;
u32 mode;
ulong clk;
clk = priv->clk_rate;
if (clk / 64 > speed) {
div16 = SPI_MODE_DIV16;
clk /= 16;
} else {
div16 = 0;
}
pm = (clk - 1)/(4*speed) + 1;
if (pm > 16) {
dev_err(dev, "requested speed %u too small\n", speed);
return -EINVAL;
}
pm--;
bits = div16 | (pm << SPI_MODE_PM_SHIFT);
mask = SPI_MODE_DIV16 | SPI_MODE_PM_MASK;
mode = in_be32(&spi->mode);
if ((mode & mask) != bits) {
/* Must clear mode[EN] while changing speed. */
mode &= ~(mask | SPI_MODE_EN);
out_be32(&spi->mode, mode);
mode |= bits;
out_be32(&spi->mode, mode);
mode |= SPI_MODE_EN;
out_be32(&spi->mode, mode);
}
debug("requested speed %u, set speed to %lu/(%s4*%u) == %lu\n",
speed, priv->clk_rate, div16 ? "16*" : "", pm + 1,
clk/(4*(pm + 1)));
return 0;
}
static int mpc8xxx_spi_set_mode(struct udevice *dev, uint mode)
{
/* TODO(mario.six@gdsys.cc): Using SPI_CPHA (for clock phase) and
* SPI_CPOL (for clock polarity) should work
*/
return 0;
}
static const struct dm_spi_ops mpc8xxx_spi_ops = {
.xfer = mpc8xxx_spi_xfer,
.set_speed = mpc8xxx_spi_set_speed,
.set_mode = mpc8xxx_spi_set_mode,
/*
* cs_info is not needed, since we require all chip selects to be
* in the device tree explicitly
*/
};
static const struct udevice_id mpc8xxx_spi_ids[] = {
{ .compatible = "fsl,spi" },
{ }
};
U_BOOT_DRIVER(mpc8xxx_spi) = {
.name = "mpc8xxx_spi",
.id = UCLASS_SPI,
.of_match = mpc8xxx_spi_ids,
.ops = &mpc8xxx_spi_ops,
.ofdata_to_platdata = mpc8xxx_spi_ofdata_to_platdata,
.probe = mpc8xxx_spi_probe,
.priv_auto_alloc_size = sizeof(struct mpc8xxx_priv),
};