freebsd-dev/sys/mips/atheros/ar71xx_spi.c
Oleksandr Tymoshenko 9e3ed0a7fe - Remove unnecessary register writes in activate_device
and deactivate_device
- Save state before attaching driver and restore it when
    detaching
- Clear CLK bit after last bit of byte has been sent over
    the bus providing falling edge for last byte in transfer
- Fix several places where CS0 was always assumed
- Add $FreeBSD$ to ar71xxreg.h
2010-01-21 00:15:59 +00:00

238 lines
5.8 KiB
C

/*-
* Copyright (c) 2009, Oleksandr Tymoshenko <gonzo@FreeBSD.org>
* All rights reserved.
*
* 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 unmodified, 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/interrupt.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/pmap.h>
#include <dev/spibus/spi.h>
#include <dev/spibus/spibusvar.h>
#include "spibus_if.h"
#include <mips/atheros/ar71xxreg.h>
#undef AR71XX_SPI_DEBUG
#ifdef AR71XX_SPI_DEBUG
#define dprintf printf
#else
#define dprintf(x, arg...)
#endif
/*
* register space access macros
*/
#define SPI_WRITE(sc, reg, val) do { \
bus_write_4(sc->sc_mem_res, (reg), (val)); \
} while (0)
#define SPI_READ(sc, reg) bus_read_4(sc->sc_mem_res, (reg))
#define SPI_SET_BITS(sc, reg, bits) \
SPI_WRITE(sc, reg, SPI_READ(sc, (reg)) | (bits))
#define SPI_CLEAR_BITS(sc, reg, bits) \
SPI_WRITE(sc, reg, SPI_READ(sc, (reg)) & ~(bits))
struct ar71xx_spi_softc {
device_t sc_dev;
struct resource *sc_mem_res;
uint32_t sc_reg_ctrl;
};
static int
ar71xx_spi_probe(device_t dev)
{
device_set_desc(dev, "AR71XX SPI");
return (0);
}
static int
ar71xx_spi_attach(device_t dev)
{
struct ar71xx_spi_softc *sc = device_get_softc(dev);
int rid;
sc->sc_dev = dev;
rid = 0;
sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
RF_ACTIVE);
if (!sc->sc_mem_res) {
device_printf(dev, "Could not map memory\n");
return (ENXIO);
}
SPI_WRITE(sc, AR71XX_SPI_FS, 1);
sc->sc_reg_ctrl = SPI_READ(sc, AR71XX_SPI_CTRL);
SPI_WRITE(sc, AR71XX_SPI_CTRL, 0x43);
SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, SPI_IO_CTRL_CSMASK);
device_add_child(dev, "spibus", 0);
return (bus_generic_attach(dev));
}
static void
ar71xx_spi_chip_activate(struct ar71xx_spi_softc *sc, int cs)
{
uint32_t ioctrl = SPI_IO_CTRL_CSMASK;
/*
* Put respective CSx to low
*/
ioctrl &= ~(SPI_IO_CTRL_CS0 << cs);
SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, ioctrl);
}
static void
ar71xx_spi_chip_deactivate(struct ar71xx_spi_softc *sc, int cs)
{
/*
* Put all CSx to high
*/
SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, SPI_IO_CTRL_CSMASK);
}
static uint8_t
ar71xx_spi_txrx(struct ar71xx_spi_softc *sc, int cs, uint8_t data)
{
int bit;
/* CS0 */
uint32_t ioctrl = SPI_IO_CTRL_CSMASK;
/*
* low-level for selected CS
*/
ioctrl &= ~(SPI_IO_CTRL_CS0 << cs);
uint32_t iod, rds;
for (bit = 7; bit >=0; bit--) {
if (data & (1 << bit))
iod = ioctrl | SPI_IO_CTRL_DO;
else
iod = ioctrl & ~SPI_IO_CTRL_DO;
SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, iod);
SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, iod | SPI_IO_CTRL_CLK);
}
/*
* Provide falling edge for connected device by clear clock bit.
*/
SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, iod);
rds = SPI_READ(sc, AR71XX_SPI_RDS);
return (rds & 0xff);
}
static int
ar71xx_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
{
struct ar71xx_spi_softc *sc;
uint8_t *buf_in, *buf_out;
struct spibus_ivar *devi = SPIBUS_IVAR(child);
int i;
sc = device_get_softc(dev);
ar71xx_spi_chip_activate(sc, devi->cs);
KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
("TX/RX command sizes should be equal"));
KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
("TX/RX data sizes should be equal"));
/*
* Transfer command
*/
buf_out = (uint8_t *)cmd->tx_cmd;
buf_in = (uint8_t *)cmd->rx_cmd;
for (i = 0; i < cmd->tx_cmd_sz; i++)
buf_in[i] = ar71xx_spi_txrx(sc, devi->cs, buf_out[i]);
/*
* Receive/transmit data (depends on command)
*/
buf_out = (uint8_t *)cmd->tx_data;
buf_in = (uint8_t *)cmd->rx_data;
for (i = 0; i < cmd->tx_data_sz; i++)
buf_in[i] = ar71xx_spi_txrx(sc, devi->cs, buf_out[i]);
ar71xx_spi_chip_deactivate(sc, devi->cs);
return (0);
}
static int
ar71xx_spi_detach(device_t dev)
{
struct ar71xx_spi_softc *sc = device_get_softc(dev);
SPI_WRITE(sc, AR71XX_SPI_CTRL, sc->sc_reg_ctrl);
SPI_WRITE(sc, AR71XX_SPI_FS, 0);
if (sc->sc_mem_res)
bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
return (0);
}
static device_method_t ar71xx_spi_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, ar71xx_spi_probe),
DEVMETHOD(device_attach, ar71xx_spi_attach),
DEVMETHOD(device_detach, ar71xx_spi_detach),
DEVMETHOD(spibus_transfer, ar71xx_spi_transfer),
{0, 0}
};
static driver_t ar71xx_spi_driver = {
"spi",
ar71xx_spi_methods,
sizeof(struct ar71xx_spi_softc),
};
static devclass_t ar71xx_spi_devclass;
DRIVER_MODULE(ar71xx_spi, nexus, ar71xx_spi_driver, ar71xx_spi_devclass, 0, 0);