freebsd-skq/sys/dev/xilinx/axi_quad_spi.c
2016-04-19 15:36:18 +00:00

234 lines
6.4 KiB
C

/*-
* Copyright (c) 2016 Ruslan Bukin <br@bsdpad.com>
* All rights reserved.
*
* Portions of this software were developed by SRI International and the
* University of Cambridge Computer Laboratory under DARPA/AFRL contract
* FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
*
* Portions of this software were developed by the University of Cambridge
* Computer Laboratory as part of the CTSRD Project, with support from the
* UK Higher Education Innovation Fund (HEIF).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Xilinx AXI_QUAD_SPI
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/rman.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <sys/watchdog.h>
#include <dev/spibus/spi.h>
#include <dev/spibus/spibusvar.h>
#include "spibus_if.h"
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/intr.h>
#define READ4(_sc, _reg) \
bus_space_read_4(_sc->bst, _sc->bsh, _reg)
#define WRITE4(_sc, _reg, _val) \
bus_space_write_4(_sc->bst, _sc->bsh, _reg, _val)
#define SPI_SRR 0x40 /* Software reset register */
#define SRR_RESET 0x0A /* The only reset value */
#define SPI_CR 0x60 /* Control register */
#define CR_LSB_FIRST (1 << 9) /* LSB first */
#define CR_MASTER_TI (1 << 8) /* Master Transaction Inhibit */
#define CR_MSS (1 << 7) /* Manual Slave Select */
#define CR_RST_RX (1 << 6) /* RX FIFO Reset */
#define CR_RST_TX (1 << 5) /* TX FIFO Reset */
#define CR_CPHA (1 << 4) /* Clock phase */
#define CR_CPOL (1 << 3) /* Clock polarity */
#define CR_MASTER (1 << 2) /* Master (SPI master mode) */
#define CR_SPE (1 << 1) /* SPI system enable */
#define CR_LOOP (1 << 0) /* Local loopback mode */
#define SPI_SR 0x64 /* Status register */
#define SR_TX_FULL (1 << 3) /* Transmit full */
#define SR_TX_EMPTY (1 << 2) /* Transmit empty */
#define SR_RX_FULL (1 << 1) /* Receive full */
#define SR_RX_EMPTY (1 << 0) /* Receive empty */
#define SPI_DTR 0x68 /* Data transmit register */
#define SPI_DRR 0x6C /* Data receive register */
#define SPI_SSR 0x70 /* Slave select register */
#define SPI_TFOR 0x74 /* Transmit FIFO Occupancy Register */
#define SPI_RFOR 0x78 /* Receive FIFO Occupancy Register */
#define SPI_DGIER 0x1C /* Device global interrupt enable register */
#define SPI_IPISR 0x20 /* IP interrupt status register */
#define SPI_IPIER 0x28 /* IP interrupt enable register */
struct spi_softc {
struct resource *res[1];
bus_space_tag_t bst;
bus_space_handle_t bsh;
void *ih;
};
static struct resource_spec spi_spec[] = {
{ SYS_RES_MEMORY, 0, RF_ACTIVE },
{ -1, 0 }
};
static int
spi_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "xlnx,xps-spi-3.2"))
return (ENXIO);
device_set_desc(dev, "Xilinx Quad SPI");
return (BUS_PROBE_DEFAULT);
}
static int
spi_attach(device_t dev)
{
struct spi_softc *sc;
uint32_t reg;
sc = device_get_softc(dev);
if (bus_alloc_resources(dev, spi_spec, sc->res)) {
device_printf(dev, "could not allocate resources\n");
return (ENXIO);
}
/* Memory interface */
sc->bst = rman_get_bustag(sc->res[0]);
sc->bsh = rman_get_bushandle(sc->res[0]);
/* Reset */
WRITE4(sc, SPI_SRR, SRR_RESET);
DELAY(1000);
reg = (CR_MASTER | CR_MSS | CR_RST_RX | CR_RST_TX);
WRITE4(sc, SPI_CR, reg);
WRITE4(sc, SPI_DGIER, 0); /* Disable interrupts */
reg = (CR_MASTER | CR_MSS | CR_SPE);
WRITE4(sc, SPI_CR, reg);
device_add_child(dev, "spibus", 0);
return (bus_generic_attach(dev));
}
static int
spi_txrx(struct spi_softc *sc, uint8_t *out_buf,
uint8_t *in_buf, int bufsz, int cs)
{
uint32_t data;
uint32_t i;
for (i = 0; i < bufsz; i++) {
WRITE4(sc, SPI_DTR, out_buf[i]);
while(!(READ4(sc, SPI_SR) & SR_TX_EMPTY))
continue;
data = READ4(sc, SPI_DRR);
if (in_buf)
in_buf[i] = (data & 0xff);
}
return (0);
}
static int
spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
{
struct spi_softc *sc;
uint32_t reg;
uint32_t cs;
sc = device_get_softc(dev);
KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
("%s: TX/RX command sizes should be equal", __func__));
KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
("%s: TX/RX data sizes should be equal", __func__));
/* get the proper chip select */
spibus_get_cs(child, &cs);
/* Assert CS */
reg = READ4(sc, SPI_SSR);
reg &= ~(1 << cs);
WRITE4(sc, SPI_SSR, reg);
/* Command */
spi_txrx(sc, cmd->tx_cmd, cmd->rx_cmd, cmd->tx_cmd_sz, cs);
/* Data */
spi_txrx(sc, cmd->tx_data, cmd->rx_data, cmd->tx_data_sz, cs);
/* Deassert CS */
reg = READ4(sc, SPI_SSR);
reg |= (1 << cs);
WRITE4(sc, SPI_SSR, reg);
return (0);
}
static device_method_t spi_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, spi_probe),
DEVMETHOD(device_attach, spi_attach),
/* SPI interface */
DEVMETHOD(spibus_transfer, spi_transfer),
DEVMETHOD_END
};
static driver_t spi_driver = {
"spi",
spi_methods,
sizeof(struct spi_softc),
};
static devclass_t spi_devclass;
DRIVER_MODULE(spi, simplebus, spi_driver, spi_devclass, 0, 0);