mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-19 00:18:51 +09:00
![Simon Glass](/assets/img/avatar_default.png)
Add a new implementation of soft_spi that uses device tree to specify the GPIOs. This will replace soft_spi_legacy for boards which use driver model. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
253 lines
6.1 KiB
C
253 lines
6.1 KiB
C
/*
|
|
* Copyright (c) 2014 Google, Inc
|
|
*
|
|
* (C) Copyright 2002
|
|
* Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
|
|
*
|
|
* Influenced by code from:
|
|
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <dm.h>
|
|
#include <errno.h>
|
|
#include <fdtdec.h>
|
|
#include <malloc.h>
|
|
#include <spi.h>
|
|
#include <asm/gpio.h>
|
|
|
|
DECLARE_GLOBAL_DATA_PTR;
|
|
|
|
struct soft_spi_platdata {
|
|
struct fdt_gpio_state cs;
|
|
struct fdt_gpio_state sclk;
|
|
struct fdt_gpio_state mosi;
|
|
struct fdt_gpio_state miso;
|
|
int spi_delay_us;
|
|
};
|
|
|
|
struct soft_spi_priv {
|
|
unsigned int mode;
|
|
};
|
|
|
|
static int soft_spi_scl(struct udevice *dev, int bit)
|
|
{
|
|
struct soft_spi_platdata *plat = dev->platdata;
|
|
struct soft_spi_priv *priv = dev_get_priv(dev);
|
|
|
|
gpio_set_value(plat->sclk.gpio, priv->mode & SPI_CPOL ? bit : !bit);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int soft_spi_sda(struct udevice *dev, int bit)
|
|
{
|
|
struct soft_spi_platdata *plat = dev->platdata;
|
|
|
|
gpio_set_value(plat->mosi.gpio, bit);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int soft_spi_cs_activate(struct udevice *dev)
|
|
{
|
|
struct soft_spi_platdata *plat = dev->platdata;
|
|
struct soft_spi_priv *priv = dev_get_priv(dev);
|
|
|
|
gpio_set_value(plat->cs.gpio, !(priv->mode & SPI_CS_HIGH));
|
|
gpio_set_value(plat->sclk.gpio, priv->mode & SPI_CPOL);
|
|
gpio_set_value(plat->cs.gpio, priv->mode & SPI_CS_HIGH);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int soft_spi_cs_deactivate(struct udevice *dev)
|
|
{
|
|
struct soft_spi_platdata *plat = dev->platdata;
|
|
struct soft_spi_priv *priv = dev_get_priv(dev);
|
|
|
|
gpio_set_value(plat->cs.gpio, !(priv->mode & SPI_CS_HIGH));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int soft_spi_claim_bus(struct udevice *dev)
|
|
{
|
|
/*
|
|
* Make sure the SPI clock is in idle state as defined for
|
|
* this slave.
|
|
*/
|
|
return soft_spi_scl(dev, 0);
|
|
}
|
|
|
|
static int soft_spi_release_bus(struct udevice *dev)
|
|
{
|
|
/* Nothing to do */
|
|
return 0;
|
|
}
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* SPI transfer
|
|
*
|
|
* This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
|
|
* "bitlen" bits in the SPI MISO port. That's just the way SPI works.
|
|
*
|
|
* The source of the outgoing bits is the "dout" parameter and the
|
|
* destination of the input bits is the "din" parameter. Note that "dout"
|
|
* and "din" can point to the same memory location, in which case the
|
|
* input data overwrites the output data (since both are buffered by
|
|
* temporary variables, this is OK).
|
|
*/
|
|
static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,
|
|
const void *dout, void *din, unsigned long flags)
|
|
{
|
|
struct soft_spi_priv *priv = dev_get_priv(dev);
|
|
struct soft_spi_platdata *plat = dev->platdata;
|
|
uchar tmpdin = 0;
|
|
uchar tmpdout = 0;
|
|
const u8 *txd = dout;
|
|
u8 *rxd = din;
|
|
int cpol = priv->mode & SPI_CPOL;
|
|
int cpha = priv->mode & SPI_CPHA;
|
|
unsigned int j;
|
|
|
|
debug("spi_xfer: slave %s:%s dout %08X din %08X bitlen %u\n",
|
|
dev->parent->name, dev->name, *(uint *)txd, *(uint *)rxd,
|
|
bitlen);
|
|
|
|
if (flags & SPI_XFER_BEGIN)
|
|
soft_spi_cs_activate(dev);
|
|
|
|
for (j = 0; j < bitlen; j++) {
|
|
/*
|
|
* Check if it is time to work on a new byte.
|
|
*/
|
|
if ((j % 8) == 0) {
|
|
if (txd)
|
|
tmpdout = *txd++;
|
|
else
|
|
tmpdout = 0;
|
|
if (j != 0) {
|
|
if (rxd)
|
|
*rxd++ = tmpdin;
|
|
}
|
|
tmpdin = 0;
|
|
}
|
|
|
|
if (!cpha)
|
|
soft_spi_scl(dev, !cpol);
|
|
soft_spi_sda(dev, tmpdout & 0x80);
|
|
udelay(plat->spi_delay_us);
|
|
if (cpha)
|
|
soft_spi_scl(dev, !cpol);
|
|
else
|
|
soft_spi_scl(dev, cpol);
|
|
tmpdin <<= 1;
|
|
tmpdin |= gpio_get_value(plat->miso.gpio);
|
|
tmpdout <<= 1;
|
|
udelay(plat->spi_delay_us);
|
|
if (cpha)
|
|
soft_spi_scl(dev, cpol);
|
|
}
|
|
/*
|
|
* If the number of bits isn't a multiple of 8, shift the last
|
|
* bits over to left-justify them. Then store the last byte
|
|
* read in.
|
|
*/
|
|
if (rxd) {
|
|
if ((bitlen % 8) != 0)
|
|
tmpdin <<= 8 - (bitlen % 8);
|
|
*rxd++ = tmpdin;
|
|
}
|
|
|
|
if (flags & SPI_XFER_END)
|
|
soft_spi_cs_deactivate(dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int soft_spi_set_speed(struct udevice *dev, unsigned int speed)
|
|
{
|
|
/* Accept any speed */
|
|
return 0;
|
|
}
|
|
|
|
static int soft_spi_set_mode(struct udevice *dev, unsigned int mode)
|
|
{
|
|
struct soft_spi_priv *priv = dev_get_priv(dev);
|
|
|
|
priv->mode = mode;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int soft_spi_child_pre_probe(struct udevice *dev)
|
|
{
|
|
struct spi_slave *slave = dev_get_parentdata(dev);
|
|
|
|
slave->dev = dev;
|
|
return spi_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, slave);
|
|
}
|
|
|
|
static const struct dm_spi_ops soft_spi_ops = {
|
|
.claim_bus = soft_spi_claim_bus,
|
|
.release_bus = soft_spi_release_bus,
|
|
.xfer = soft_spi_xfer,
|
|
.set_speed = soft_spi_set_speed,
|
|
.set_mode = soft_spi_set_mode,
|
|
};
|
|
|
|
static int soft_spi_ofdata_to_platdata(struct udevice *dev)
|
|
{
|
|
struct soft_spi_platdata *plat = dev->platdata;
|
|
const void *blob = gd->fdt_blob;
|
|
int node = dev->of_offset;
|
|
|
|
if (fdtdec_decode_gpio(blob, node, "cs-gpio", &plat->cs) ||
|
|
fdtdec_decode_gpio(blob, node, "sclk-gpio", &plat->sclk) ||
|
|
fdtdec_decode_gpio(blob, node, "mosi-gpio", &plat->mosi) ||
|
|
fdtdec_decode_gpio(blob, node, "miso-gpio", &plat->miso))
|
|
return -EINVAL;
|
|
plat->spi_delay_us = fdtdec_get_int(blob, node, "spi-delay-us", 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int soft_spi_probe(struct udevice *dev)
|
|
{
|
|
struct spi_slave *slave = dev_get_parentdata(dev);
|
|
struct soft_spi_platdata *plat = dev->platdata;
|
|
|
|
gpio_request(plat->cs.gpio, "soft_spi_cs");
|
|
gpio_request(plat->sclk.gpio, "soft_spi_sclk");
|
|
gpio_request(plat->mosi.gpio, "soft_spi_mosi");
|
|
gpio_request(plat->miso.gpio, "soft_spi_miso");
|
|
|
|
gpio_direction_output(plat->sclk.gpio, slave->mode & SPI_CPOL);
|
|
gpio_direction_output(plat->mosi.gpio, 1);
|
|
gpio_direction_input(plat->miso.gpio);
|
|
gpio_direction_output(plat->cs.gpio, !(slave->mode & SPI_CS_HIGH));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct udevice_id soft_spi_ids[] = {
|
|
{ .compatible = "u-boot,soft-spi" },
|
|
{ }
|
|
};
|
|
|
|
U_BOOT_DRIVER(soft_spi) = {
|
|
.name = "soft_spi",
|
|
.id = UCLASS_SPI,
|
|
.of_match = soft_spi_ids,
|
|
.ops = &soft_spi_ops,
|
|
.ofdata_to_platdata = soft_spi_ofdata_to_platdata,
|
|
.platdata_auto_alloc_size = sizeof(struct soft_spi_platdata),
|
|
.priv_auto_alloc_size = sizeof(struct soft_spi_priv),
|
|
.per_child_auto_alloc_size = sizeof(struct spi_slave),
|
|
.probe = soft_spi_probe,
|
|
.child_pre_probe = soft_spi_child_pre_probe,
|
|
};
|