freebsd-dev/sys/arm/lpc/lpc_spi.c

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/*-
* Copyright (c) 2011 Jakub Wojciech Klama <jceel@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, 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/bio.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/queue.h>
#include <sys/resource.h>
#include <sys/rman.h>
#include <sys/time.h>
#include <sys/timetc.h>
#include <sys/watchdog.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/cpufunc.h>
#include <machine/resource.h>
#include <machine/frame.h>
#include <machine/intr.h>
#include <dev/spibus/spi.h>
#include <dev/spibus/spibusvar.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <arm/lpc/lpcreg.h>
#include <arm/lpc/lpcvar.h>
#include "spibus_if.h"
struct lpc_spi_softc
{
device_t ls_dev;
struct resource * ls_mem_res;
struct resource * ls_irq_res;
bus_space_tag_t ls_bst;
bus_space_handle_t ls_bsh;
};
static int lpc_spi_probe(device_t);
static int lpc_spi_attach(device_t);
static int lpc_spi_detach(device_t);
static int lpc_spi_transfer(device_t, device_t, struct spi_command *);
#define lpc_spi_read_4(_sc, _reg) \
bus_space_read_4(_sc->ls_bst, _sc->ls_bsh, _reg)
#define lpc_spi_write_4(_sc, _reg, _val) \
bus_space_write_4(_sc->ls_bst, _sc->ls_bsh, _reg, _val)
static int
lpc_spi_probe(device_t dev)
{
if (!ofw_bus_is_compatible(dev, "lpc,spi"))
return (ENXIO);
device_set_desc(dev, "LPC32x0 PL022 SPI/SSP controller");
return (BUS_PROBE_DEFAULT);
}
static int
lpc_spi_attach(device_t dev)
{
struct lpc_spi_softc *sc = device_get_softc(dev);
int rid;
sc->ls_dev = dev;
rid = 0;
sc->ls_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
RF_ACTIVE);
if (!sc->ls_mem_res) {
device_printf(dev, "cannot allocate memory window\n");
return (ENXIO);
}
sc->ls_bst = rman_get_bustag(sc->ls_mem_res);
sc->ls_bsh = rman_get_bushandle(sc->ls_mem_res);
rid = 0;
sc->ls_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_ACTIVE);
if (!sc->ls_irq_res) {
device_printf(dev, "cannot allocate interrupt\n");
return (ENXIO);
}
bus_space_write_4(sc->ls_bst, 0xd0028100, 0, (1<<12)|(1<<10)|(1<<9)|(1<<8)|(1<<6)|(1<<5));
lpc_pwr_write(dev, LPC_CLKPWR_SSP_CTRL, LPC_CLKPWR_SSP_CTRL_SSP0EN);
lpc_spi_write_4(sc, LPC_SSP_CR0, LPC_SSP_CR0_DSS(8));
lpc_spi_write_4(sc, LPC_SSP_CR1, LPC_SSP_CR1_SSE);
lpc_spi_write_4(sc, LPC_SSP_CPSR, 128);
device_add_child(dev, "spibus", 0);
return (bus_generic_attach(dev));
}
static int
lpc_spi_detach(device_t dev)
{
return (EBUSY);
}
static int
lpc_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
{
struct lpc_spi_softc *sc = device_get_softc(dev);
struct spibus_ivar *devi = SPIBUS_IVAR(child);
uint8_t *in_buf, *out_buf;
int i;
/* Set CS active */
lpc_gpio_set_state(child, devi->cs, 0);
/* Wait for FIFO to be ready */
while ((lpc_spi_read_4(sc, LPC_SSP_SR) & LPC_SSP_SR_TNF) == 0);
/* Command */
in_buf = cmd->rx_cmd;
out_buf = cmd->tx_cmd;
for (i = 0; i < cmd->tx_cmd_sz; i++) {
lpc_spi_write_4(sc, LPC_SSP_DR, out_buf[i]);
in_buf[i] = lpc_spi_read_4(sc, LPC_SSP_DR);
}
/* Data */
in_buf = cmd->rx_data;
out_buf = cmd->tx_data;
for (i = 0; i < cmd->tx_data_sz; i++) {
lpc_spi_write_4(sc, LPC_SSP_DR, out_buf[i]);
in_buf[i] = lpc_spi_read_4(sc, LPC_SSP_DR);
}
/* Set CS inactive */
lpc_gpio_set_state(child, devi->cs, 1);
return (0);
}
static device_method_t lpc_spi_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, lpc_spi_probe),
DEVMETHOD(device_attach, lpc_spi_attach),
DEVMETHOD(device_detach, lpc_spi_detach),
/* SPI interface */
DEVMETHOD(spibus_transfer, lpc_spi_transfer),
{ 0, 0 }
};
static devclass_t lpc_spi_devclass;
static driver_t lpc_spi_driver = {
"spi",
lpc_spi_methods,
sizeof(struct lpc_spi_softc),
};
DRIVER_MODULE(lpcspi, simplebus, lpc_spi_driver, lpc_spi_devclass, 0, 0);