Jetpack/u-boot/drivers/spi/altera_spi.c

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/*
* Altera SPI driver
*
* based on bfin_spi.c
* Copyright (c) 2005-2008 Analog Devices Inc.
* Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <malloc.h>
#include <fdtdec.h>
#include <spi.h>
#include <asm/io.h>
DECLARE_GLOBAL_DATA_PTR;
#define ALTERA_SPI_STATUS_RRDY_MSK BIT(7)
#define ALTERA_SPI_CONTROL_SSO_MSK BIT(10)
#ifndef CONFIG_ALTERA_SPI_IDLE_VAL
#define CONFIG_ALTERA_SPI_IDLE_VAL 0xff
#endif
struct altera_spi_regs {
u32 rxdata;
u32 txdata;
u32 status;
u32 control;
u32 _reserved;
u32 slave_sel;
};
struct altera_spi_platdata {
struct altera_spi_regs *regs;
};
struct altera_spi_priv {
struct altera_spi_regs *regs;
};
static void spi_cs_activate(struct udevice *dev, uint cs)
{
struct udevice *bus = dev->parent;
struct altera_spi_priv *priv = dev_get_priv(bus);
struct altera_spi_regs *const regs = priv->regs;
writel(1 << cs, &regs->slave_sel);
writel(ALTERA_SPI_CONTROL_SSO_MSK, &regs->control);
}
static void spi_cs_deactivate(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct altera_spi_priv *priv = dev_get_priv(bus);
struct altera_spi_regs *const regs = priv->regs;
writel(0, &regs->control);
writel(0, &regs->slave_sel);
}
static int altera_spi_claim_bus(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct altera_spi_priv *priv = dev_get_priv(bus);
struct altera_spi_regs *const regs = priv->regs;
writel(0, &regs->control);
writel(0, &regs->slave_sel);
return 0;
}
static int altera_spi_release_bus(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct altera_spi_priv *priv = dev_get_priv(bus);
struct altera_spi_regs *const regs = priv->regs;
writel(0, &regs->slave_sel);
return 0;
}
static int altera_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = dev->parent;
struct altera_spi_priv *priv = dev_get_priv(bus);
struct altera_spi_regs *const regs = priv->regs;
struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
/* assume spi core configured to do 8 bit transfers */
unsigned int bytes = bitlen / 8;
const unsigned char *txp = dout;
unsigned char *rxp = din;
uint32_t reg, data, start;
debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
bus->seq, slave_plat->cs, bitlen, bytes, flags);
if (bitlen == 0)
goto done;
if (bitlen % 8) {
flags |= SPI_XFER_END;
goto done;
}
/* empty read buffer */
if (readl(&regs->status) & ALTERA_SPI_STATUS_RRDY_MSK)
readl(&regs->rxdata);
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(dev, slave_plat->cs);
while (bytes--) {
if (txp)
data = *txp++;
else
data = CONFIG_ALTERA_SPI_IDLE_VAL;
debug("%s: tx:%x ", __func__, data);
writel(data, &regs->txdata);
start = get_timer(0);
while (1) {
reg = readl(&regs->status);
if (reg & ALTERA_SPI_STATUS_RRDY_MSK)
break;
if (get_timer(start) > (CONFIG_SYS_HZ / 1000)) {
debug("%s: Transmission timed out!\n", __func__);
return -1;
}
}
data = readl(&regs->rxdata);
if (rxp)
*rxp++ = data & 0xff;
debug("rx:%x\n", data);
}
done:
if (flags & SPI_XFER_END)
spi_cs_deactivate(dev);
return 0;
}
static int altera_spi_set_speed(struct udevice *bus, uint speed)
{
return 0;
}
static int altera_spi_set_mode(struct udevice *bus, uint mode)
{
return 0;
}
static int altera_spi_probe(struct udevice *bus)
{
struct altera_spi_platdata *plat = dev_get_platdata(bus);
struct altera_spi_priv *priv = dev_get_priv(bus);
priv->regs = plat->regs;
return 0;
}
static int altera_spi_ofdata_to_platdata(struct udevice *bus)
{
struct altera_spi_platdata *plat = dev_get_platdata(bus);
plat->regs = map_physmem(dev_get_addr(bus),
sizeof(struct altera_spi_regs),
MAP_NOCACHE);
return 0;
}
static const struct dm_spi_ops altera_spi_ops = {
.claim_bus = altera_spi_claim_bus,
.release_bus = altera_spi_release_bus,
.xfer = altera_spi_xfer,
.set_speed = altera_spi_set_speed,
.set_mode = altera_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 altera_spi_ids[] = {
{ .compatible = "altr,spi-1.0" },
{}
};
U_BOOT_DRIVER(altera_spi) = {
.name = "altera_spi",
.id = UCLASS_SPI,
.of_match = altera_spi_ids,
.ops = &altera_spi_ops,
.ofdata_to_platdata = altera_spi_ofdata_to_platdata,
.platdata_auto_alloc_size = sizeof(struct altera_spi_platdata),
.priv_auto_alloc_size = sizeof(struct altera_spi_priv),
.probe = altera_spi_probe,
};