freebsd-dev/sys/arm/broadcom/bcm2835/bcm2835_spi.c
Ian Lepore add35ed5b8 Follow r261352 by updating all drivers which are children of simplebus
to check the status property in their probe routines.

Simplebus used to only instantiate its children whose status="okay"
but that was improper behavior, fixed in r261352.  Now that it doesn't
check anymore and probes all its children; the children all have to
do the check because really only the children know how to properly
interpret their status property strings.

Right now all existing drivers only understand "okay" versus something-
that's-not-okay, so they all use the new ofw_bus_status_okay() helper.
2014-02-02 19:17:28 +00:00

524 lines
13 KiB
C

/*-
* Copyright (c) 2012 Oleksandr Tymoshenko <gonzo@freebsd.org>
* Copyright (c) 2013 Luiz Otavio O Souza <loos@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/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/cpufunc.h>
#include <machine/resource.h>
#include <machine/fdt.h>
#include <machine/intr.h>
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/spibus/spi.h>
#include <dev/spibus/spibusvar.h>
#include <arm/broadcom/bcm2835/bcm2835_gpio.h>
#include <arm/broadcom/bcm2835/bcm2835_spireg.h>
#include <arm/broadcom/bcm2835/bcm2835_spivar.h>
#include "spibus_if.h"
static void bcm_spi_intr(void *);
#ifdef BCM_SPI_DEBUG
static void
bcm_spi_printr(device_t dev)
{
struct bcm_spi_softc *sc;
uint32_t reg;
sc = device_get_softc(dev);
reg = BCM_SPI_READ(sc, SPI_CS);
device_printf(dev, "CS=%b\n", reg,
"\20\1CS0\2CS1\3CPHA\4CPOL\7CSPOL"
"\10TA\11DMAEN\12INTD\13INTR\14ADCS\15REN\16LEN"
"\21DONE\22RXD\23TXD\24RXR\25RXF\26CSPOL0\27CSPOL1"
"\30CSPOL2\31DMA_LEN\32LEN_LONG");
reg = BCM_SPI_READ(sc, SPI_CLK) & SPI_CLK_MASK;
if (reg % 2)
reg--;
if (reg == 0)
reg = 65536;
device_printf(dev, "CLK=%uMhz/%d=%luhz\n",
SPI_CORE_CLK / 1000000, reg, SPI_CORE_CLK / reg);
reg = BCM_SPI_READ(sc, SPI_DLEN) & SPI_DLEN_MASK;
device_printf(dev, "DLEN=%d\n", reg);
reg = BCM_SPI_READ(sc, SPI_LTOH) & SPI_LTOH_MASK;
device_printf(dev, "LTOH=%d\n", reg);
reg = BCM_SPI_READ(sc, SPI_DC);
device_printf(dev, "DC=RPANIC=%#x RDREQ=%#x TPANIC=%#x TDREQ=%#x\n",
(reg & SPI_DC_RPANIC_MASK) >> SPI_DC_RPANIC_SHIFT,
(reg & SPI_DC_RDREQ_MASK) >> SPI_DC_RDREQ_SHIFT,
(reg & SPI_DC_TPANIC_MASK) >> SPI_DC_TPANIC_SHIFT,
(reg & SPI_DC_TDREQ_MASK) >> SPI_DC_TDREQ_SHIFT);
}
#endif
static void
bcm_spi_modifyreg(struct bcm_spi_softc *sc, uint32_t off, uint32_t mask,
uint32_t value)
{
uint32_t reg;
mtx_assert(&sc->sc_mtx, MA_OWNED);
reg = BCM_SPI_READ(sc, off);
reg &= ~mask;
reg |= value;
BCM_SPI_WRITE(sc, off, reg);
}
static int
bcm_spi_clock_proc(SYSCTL_HANDLER_ARGS)
{
struct bcm_spi_softc *sc;
uint32_t clk;
int error;
sc = (struct bcm_spi_softc *)arg1;
BCM_SPI_LOCK(sc);
clk = BCM_SPI_READ(sc, SPI_CLK);
BCM_SPI_UNLOCK(sc);
clk &= 0xffff;
if (clk == 0)
clk = 65536;
clk = SPI_CORE_CLK / clk;
error = sysctl_handle_int(oidp, &clk, sizeof(clk), req);
if (error != 0 || req->newptr == NULL)
return (error);
clk = SPI_CORE_CLK / clk;
if (clk <= 1)
clk = 2;
else if (clk % 2)
clk--;
if (clk > 0xffff)
clk = 0;
BCM_SPI_LOCK(sc);
BCM_SPI_WRITE(sc, SPI_CLK, clk);
BCM_SPI_UNLOCK(sc);
return (0);
}
static int
bcm_spi_cs_bit_proc(SYSCTL_HANDLER_ARGS, uint32_t bit)
{
struct bcm_spi_softc *sc;
uint32_t reg;
int error;
sc = (struct bcm_spi_softc *)arg1;
BCM_SPI_LOCK(sc);
reg = BCM_SPI_READ(sc, SPI_CS);
BCM_SPI_UNLOCK(sc);
reg = (reg & bit) ? 1 : 0;
error = sysctl_handle_int(oidp, &reg, sizeof(reg), req);
if (error != 0 || req->newptr == NULL)
return (error);
if (reg)
reg = bit;
BCM_SPI_LOCK(sc);
bcm_spi_modifyreg(sc, SPI_CS, bit, reg);
BCM_SPI_UNLOCK(sc);
return (0);
}
static int
bcm_spi_cpol_proc(SYSCTL_HANDLER_ARGS)
{
return (bcm_spi_cs_bit_proc(oidp, arg1, arg2, req, SPI_CS_CPOL));
}
static int
bcm_spi_cpha_proc(SYSCTL_HANDLER_ARGS)
{
return (bcm_spi_cs_bit_proc(oidp, arg1, arg2, req, SPI_CS_CPHA));
}
static int
bcm_spi_cspol0_proc(SYSCTL_HANDLER_ARGS)
{
return (bcm_spi_cs_bit_proc(oidp, arg1, arg2, req, SPI_CS_CSPOL0));
}
static int
bcm_spi_cspol1_proc(SYSCTL_HANDLER_ARGS)
{
return (bcm_spi_cs_bit_proc(oidp, arg1, arg2, req, SPI_CS_CSPOL1));
}
static void
bcm_spi_sysctl_init(struct bcm_spi_softc *sc)
{
struct sysctl_ctx_list *ctx;
struct sysctl_oid *tree_node;
struct sysctl_oid_list *tree;
/*
* Add system sysctl tree/handlers.
*/
ctx = device_get_sysctl_ctx(sc->sc_dev);
tree_node = device_get_sysctl_tree(sc->sc_dev);
tree = SYSCTL_CHILDREN(tree_node);
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "clock",
CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
bcm_spi_clock_proc, "IU", "SPI BUS clock frequency");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "cpol",
CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
bcm_spi_cpol_proc, "IU", "SPI BUS clock polarity");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "cpha",
CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
bcm_spi_cpha_proc, "IU", "SPI BUS clock phase");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "cspol0",
CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
bcm_spi_cspol0_proc, "IU", "SPI BUS chip select 0 polarity");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "cspol1",
CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
bcm_spi_cspol1_proc, "IU", "SPI BUS chip select 1 polarity");
}
static int
bcm_spi_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "broadcom,bcm2835-spi"))
return (ENXIO);
device_set_desc(dev, "BCM2708/2835 SPI controller");
return (BUS_PROBE_DEFAULT);
}
static int
bcm_spi_attach(device_t dev)
{
struct bcm_spi_softc *sc;
device_t gpio;
int i, rid;
if (device_get_unit(dev) != 0) {
device_printf(dev, "only one SPI controller supported\n");
return (ENXIO);
}
sc = device_get_softc(dev);
sc->sc_dev = dev;
/* Configure the GPIO pins to ALT0 function to enable SPI the pins. */
gpio = devclass_get_device(devclass_find("gpio"), 0);
if (!gpio) {
device_printf(dev, "cannot find gpio0\n");
return (ENXIO);
}
for (i = 0; i < nitems(bcm_spi_pins); i++)
bcm_gpio_set_alternate(gpio, bcm_spi_pins[i], BCM_GPIO_ALT0);
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, "cannot allocate memory window\n");
return (ENXIO);
}
sc->sc_bst = rman_get_bustag(sc->sc_mem_res);
sc->sc_bsh = rman_get_bushandle(sc->sc_mem_res);
rid = 0;
sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_ACTIVE);
if (!sc->sc_irq_res) {
bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
device_printf(dev, "cannot allocate interrupt\n");
return (ENXIO);
}
/* Hook up our interrupt handler. */
if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
NULL, bcm_spi_intr, sc, &sc->sc_intrhand)) {
bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
device_printf(dev, "cannot setup the interrupt handler\n");
return (ENXIO);
}
mtx_init(&sc->sc_mtx, "bcm_spi", NULL, MTX_DEF);
/* Add sysctl nodes. */
bcm_spi_sysctl_init(sc);
#ifdef BCM_SPI_DEBUG
bcm_spi_printr(dev);
#endif
/*
* Enable the SPI controller. Clear the rx and tx FIFO.
* Defaults to SPI mode 0.
*/
BCM_SPI_WRITE(sc, SPI_CS, SPI_CS_CLEAR_RXFIFO | SPI_CS_CLEAR_TXFIFO);
/* Set the SPI clock to 500Khz. */
BCM_SPI_WRITE(sc, SPI_CLK, SPI_CORE_CLK / 500000);
#ifdef BCM_SPI_DEBUG
bcm_spi_printr(dev);
#endif
device_add_child(dev, "spibus", -1);
return (bus_generic_attach(dev));
}
static int
bcm_spi_detach(device_t dev)
{
struct bcm_spi_softc *sc;
bus_generic_detach(dev);
sc = device_get_softc(dev);
mtx_destroy(&sc->sc_mtx);
if (sc->sc_intrhand)
bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
if (sc->sc_irq_res)
bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
if (sc->sc_mem_res)
bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
return (0);
}
static void
bcm_spi_fill_fifo(struct bcm_spi_softc *sc)
{
struct spi_command *cmd;
uint32_t cs, written;
uint8_t *data;
cmd = sc->sc_cmd;
cs = BCM_SPI_READ(sc, SPI_CS) & (SPI_CS_TA | SPI_CS_TXD);
while (sc->sc_written < sc->sc_len &&
cs == (SPI_CS_TA | SPI_CS_TXD)) {
data = (uint8_t *)cmd->tx_cmd;
written = sc->sc_written++;
if (written >= cmd->tx_cmd_sz) {
data = (uint8_t *)cmd->tx_data;
written -= cmd->tx_cmd_sz;
}
BCM_SPI_WRITE(sc, SPI_FIFO, data[written]);
cs = BCM_SPI_READ(sc, SPI_CS) & (SPI_CS_TA | SPI_CS_TXD);
}
}
static void
bcm_spi_drain_fifo(struct bcm_spi_softc *sc)
{
struct spi_command *cmd;
uint32_t cs, read;
uint8_t *data;
cmd = sc->sc_cmd;
cs = BCM_SPI_READ(sc, SPI_CS) & SPI_CS_RXD;
while (sc->sc_read < sc->sc_len && cs == SPI_CS_RXD) {
data = (uint8_t *)cmd->rx_cmd;
read = sc->sc_read++;
if (read >= cmd->rx_cmd_sz) {
data = (uint8_t *)cmd->rx_data;
read -= cmd->rx_cmd_sz;
}
data[read] = BCM_SPI_READ(sc, SPI_FIFO) & 0xff;
cs = BCM_SPI_READ(sc, SPI_CS) & SPI_CS_RXD;
}
}
static void
bcm_spi_intr(void *arg)
{
struct bcm_spi_softc *sc;
sc = (struct bcm_spi_softc *)arg;
BCM_SPI_LOCK(sc);
/* Filter stray interrupts. */
if ((sc->sc_flags & BCM_SPI_BUSY) == 0) {
BCM_SPI_UNLOCK(sc);
return;
}
/* TX - Fill up the FIFO. */
bcm_spi_fill_fifo(sc);
/* RX - Drain the FIFO. */
bcm_spi_drain_fifo(sc);
/* Check for end of transfer. */
if (sc->sc_written == sc->sc_len && sc->sc_read == sc->sc_len) {
/* Disable interrupts and the SPI engine. */
bcm_spi_modifyreg(sc, SPI_CS,
SPI_CS_TA | SPI_CS_INTR | SPI_CS_INTD, 0);
wakeup(sc->sc_dev);
}
BCM_SPI_UNLOCK(sc);
}
static int
bcm_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
{
struct bcm_spi_softc *sc;
int cs, err;
sc = device_get_softc(dev);
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"));
BCM_SPI_LOCK(sc);
/* If the controller is in use wait until it is available. */
while (sc->sc_flags & BCM_SPI_BUSY)
mtx_sleep(dev, &sc->sc_mtx, 0, "bcm_spi", 0);
/* Now we have control over SPI controller. */
sc->sc_flags = BCM_SPI_BUSY;
/* Clear the FIFO. */
bcm_spi_modifyreg(sc, SPI_CS,
SPI_CS_CLEAR_RXFIFO | SPI_CS_CLEAR_TXFIFO,
SPI_CS_CLEAR_RXFIFO | SPI_CS_CLEAR_TXFIFO);
/* Get the proper chip select for this child. */
spibus_get_cs(child, &cs);
if (cs < 0 || cs > 2) {
device_printf(dev,
"Invalid chip select %d requested by %s\n", cs,
device_get_nameunit(child));
BCM_SPI_UNLOCK(sc);
return (EINVAL);
}
/* Save a pointer to the SPI command. */
sc->sc_cmd = cmd;
sc->sc_read = 0;
sc->sc_written = 0;
sc->sc_len = cmd->tx_cmd_sz + cmd->tx_data_sz;
/*
* Set the CS for this transaction, enable interrupts and announce
* we're ready to tx. This will kick off the first interrupt.
*/
bcm_spi_modifyreg(sc, SPI_CS,
SPI_CS_MASK | SPI_CS_TA | SPI_CS_INTR | SPI_CS_INTD,
cs | SPI_CS_TA | SPI_CS_INTR | SPI_CS_INTD);
/* Wait for the transaction to complete. */
err = mtx_sleep(dev, &sc->sc_mtx, 0, "bcm_spi", hz * 2);
/* Make sure the SPI engine and interrupts are disabled. */
bcm_spi_modifyreg(sc, SPI_CS, SPI_CS_TA | SPI_CS_INTR | SPI_CS_INTD, 0);
/* Clear the controller flags. */
sc->sc_flags = 0;
/*
* Check for transfer timeout. The SPI controller doesn't
* return errors.
*/
if (err == EWOULDBLOCK) {
device_printf(sc->sc_dev, "SPI error\n");
err = EIO;
}
BCM_SPI_UNLOCK(sc);
return (err);
}
static phandle_t
bcm_spi_get_node(device_t bus, device_t dev)
{
/* We only have one child, the SPI bus, which needs our own node. */
return (ofw_bus_get_node(bus));
}
static device_method_t bcm_spi_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, bcm_spi_probe),
DEVMETHOD(device_attach, bcm_spi_attach),
DEVMETHOD(device_detach, bcm_spi_detach),
/* SPI interface */
DEVMETHOD(spibus_transfer, bcm_spi_transfer),
/* ofw_bus interface */
DEVMETHOD(ofw_bus_get_node, bcm_spi_get_node),
DEVMETHOD_END
};
static devclass_t bcm_spi_devclass;
static driver_t bcm_spi_driver = {
"spi",
bcm_spi_methods,
sizeof(struct bcm_spi_softc),
};
DRIVER_MODULE(bcm2835_spi, simplebus, bcm_spi_driver, bcm_spi_devclass, 0, 0);