freebsd-dev/sys/arm/broadcom/bcm2835/bcm2835_bsc.c
Luiz Otavio O Souza b4ae2f3c55 Add a mask to match only the relative base address of BSC controllers.
This should fix the attach of BSC on RPI2 (based on andrew@ dmesg).
2015-02-16 19:06:31 +00:00

508 lines
13 KiB
C

/*-
* Copyright (c) 2001 Tsubai Masanari.
* 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/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/bus.h>
#include <machine/resource.h>
#include <machine/bus.h>
#include <sys/rman.h>
#include <sys/sysctl.h>
#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <arm/broadcom/bcm2835/bcm2835_gpio.h>
#include <arm/broadcom/bcm2835/bcm2835_bscreg.h>
#include <arm/broadcom/bcm2835/bcm2835_bscvar.h>
#include "iicbus_if.h"
static void bcm_bsc_intr(void *);
static int bcm_bsc_detach(device_t);
static void
bcm_bsc_modifyreg(struct bcm_bsc_softc *sc, uint32_t off, uint32_t mask,
uint32_t value)
{
uint32_t reg;
mtx_assert(&sc->sc_mtx, MA_OWNED);
reg = BCM_BSC_READ(sc, off);
reg &= ~mask;
reg |= value;
BCM_BSC_WRITE(sc, off, reg);
}
static int
bcm_bsc_clock_proc(SYSCTL_HANDLER_ARGS)
{
struct bcm_bsc_softc *sc;
uint32_t clk;
sc = (struct bcm_bsc_softc *)arg1;
BCM_BSC_LOCK(sc);
clk = BCM_BSC_READ(sc, BCM_BSC_CLOCK);
BCM_BSC_UNLOCK(sc);
clk &= 0xffff;
if (clk == 0)
clk = 32768;
clk = BCM_BSC_CORE_CLK / clk;
return (sysctl_handle_int(oidp, &clk, 0, req));
}
static int
bcm_bsc_clkt_proc(SYSCTL_HANDLER_ARGS)
{
struct bcm_bsc_softc *sc;
uint32_t clkt;
int error;
sc = (struct bcm_bsc_softc *)arg1;
BCM_BSC_LOCK(sc);
clkt = BCM_BSC_READ(sc, BCM_BSC_CLKT);
BCM_BSC_UNLOCK(sc);
clkt &= 0xffff;
error = sysctl_handle_int(oidp, &clkt, sizeof(clkt), req);
if (error != 0 || req->newptr == NULL)
return (error);
BCM_BSC_LOCK(sc);
BCM_BSC_WRITE(sc, BCM_BSC_CLKT, clkt & 0xffff);
BCM_BSC_UNLOCK(sc);
return (0);
}
static int
bcm_bsc_fall_proc(SYSCTL_HANDLER_ARGS)
{
struct bcm_bsc_softc *sc;
uint32_t clk, reg;
int error;
sc = (struct bcm_bsc_softc *)arg1;
BCM_BSC_LOCK(sc);
reg = BCM_BSC_READ(sc, BCM_BSC_DELAY);
BCM_BSC_UNLOCK(sc);
reg >>= 16;
error = sysctl_handle_int(oidp, &reg, sizeof(reg), req);
if (error != 0 || req->newptr == NULL)
return (error);
BCM_BSC_LOCK(sc);
clk = BCM_BSC_READ(sc, BCM_BSC_CLOCK);
clk = BCM_BSC_CORE_CLK / clk;
if (reg > clk / 2)
reg = clk / 2 - 1;
bcm_bsc_modifyreg(sc, BCM_BSC_DELAY, 0xffff0000, reg << 16);
BCM_BSC_UNLOCK(sc);
return (0);
}
static int
bcm_bsc_rise_proc(SYSCTL_HANDLER_ARGS)
{
struct bcm_bsc_softc *sc;
uint32_t clk, reg;
int error;
sc = (struct bcm_bsc_softc *)arg1;
BCM_BSC_LOCK(sc);
reg = BCM_BSC_READ(sc, BCM_BSC_DELAY);
BCM_BSC_UNLOCK(sc);
reg &= 0xffff;
error = sysctl_handle_int(oidp, &reg, sizeof(reg), req);
if (error != 0 || req->newptr == NULL)
return (error);
BCM_BSC_LOCK(sc);
clk = BCM_BSC_READ(sc, BCM_BSC_CLOCK);
clk = BCM_BSC_CORE_CLK / clk;
if (reg > clk / 2)
reg = clk / 2 - 1;
bcm_bsc_modifyreg(sc, BCM_BSC_DELAY, 0xffff, reg);
BCM_BSC_UNLOCK(sc);
return (0);
}
static void
bcm_bsc_sysctl_init(struct bcm_bsc_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, "frequency",
CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
bcm_bsc_clock_proc, "IU", "I2C BUS clock frequency");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "clock_stretch",
CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
bcm_bsc_clkt_proc, "IU", "I2C BUS clock stretch timeout");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "fall_edge_delay",
CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
bcm_bsc_fall_proc, "IU", "I2C BUS falling edge delay");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "rise_edge_delay",
CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
bcm_bsc_rise_proc, "IU", "I2C BUS rising edge delay");
}
static void
bcm_bsc_reset(struct bcm_bsc_softc *sc)
{
/* Enable the BSC Controller, disable interrupts. */
BCM_BSC_WRITE(sc, BCM_BSC_CTRL, BCM_BSC_CTRL_I2CEN);
/* Clear pending interrupts. */
BCM_BSC_WRITE(sc, BCM_BSC_STATUS, BCM_BSC_STATUS_CLKT |
BCM_BSC_STATUS_ERR | BCM_BSC_STATUS_DONE);
/* Clear the FIFO. */
bcm_bsc_modifyreg(sc, BCM_BSC_CTRL, BCM_BSC_CTRL_CLEAR0,
BCM_BSC_CTRL_CLEAR0);
}
static int
bcm_bsc_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "broadcom,bcm2835-bsc"))
return (ENXIO);
device_set_desc(dev, "BCM2708/2835 BSC controller");
return (BUS_PROBE_DEFAULT);
}
static int
bcm_bsc_attach(device_t dev)
{
struct bcm_bsc_softc *sc;
unsigned long start;
device_t gpio;
int i, rid;
sc = device_get_softc(dev);
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, "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);
/* Check the unit we are attaching by its base address. */
start = rman_get_start(sc->sc_mem_res);
for (i = 0; i < nitems(bcm_bsc_pins); i++) {
if (bcm_bsc_pins[i].start == (start & BCM_BSC_BASE_MASK))
break;
}
if (i == nitems(bcm_bsc_pins)) {
device_printf(dev, "only bsc0 and bsc1 are supported\n");
bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
return (ENXIO);
}
/*
* Configure the GPIO pins to ALT0 function to enable BSC control
* over the pins.
*/
gpio = devclass_get_device(devclass_find("gpio"), 0);
if (!gpio) {
device_printf(dev, "cannot find gpio0\n");
bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
return (ENXIO);
}
bcm_gpio_set_alternate(gpio, bcm_bsc_pins[i].sda, BCM_GPIO_ALT0);
bcm_gpio_set_alternate(gpio, bcm_bsc_pins[i].scl, BCM_GPIO_ALT0);
rid = 0;
sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_ACTIVE | RF_SHAREABLE);
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_bsc_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_bsc", NULL, MTX_DEF);
bcm_bsc_sysctl_init(sc);
/* Enable the BSC controller. Flush the FIFO. */
BCM_BSC_LOCK(sc);
bcm_bsc_reset(sc);
BCM_BSC_UNLOCK(sc);
sc->sc_iicbus = device_add_child(dev, "iicbus", -1);
if (sc->sc_iicbus == NULL) {
bcm_bsc_detach(dev);
return (ENXIO);
}
return (bus_generic_attach(dev));
}
static int
bcm_bsc_detach(device_t dev)
{
struct bcm_bsc_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_bsc_intr(void *arg)
{
struct bcm_bsc_softc *sc;
uint32_t status;
sc = (struct bcm_bsc_softc *)arg;
BCM_BSC_LOCK(sc);
/* The I2C interrupt is shared among all the BSC controllers. */
if ((sc->sc_flags & BCM_I2C_BUSY) == 0) {
BCM_BSC_UNLOCK(sc);
return;
}
status = BCM_BSC_READ(sc, BCM_BSC_STATUS);
/* Check for errors. */
if (status & (BCM_BSC_STATUS_CLKT | BCM_BSC_STATUS_ERR)) {
/* Disable interrupts. */
bcm_bsc_reset(sc);
sc->sc_flags |= BCM_I2C_ERROR;
wakeup(sc->sc_dev);
BCM_BSC_UNLOCK(sc);
return;
}
if (sc->sc_flags & BCM_I2C_READ) {
while (sc->sc_resid > 0 && (status & BCM_BSC_STATUS_RXD)) {
*sc->sc_data++ = BCM_BSC_READ(sc, BCM_BSC_DATA);
sc->sc_resid--;
status = BCM_BSC_READ(sc, BCM_BSC_STATUS);
}
} else {
while (sc->sc_resid > 0 && (status & BCM_BSC_STATUS_TXD)) {
BCM_BSC_WRITE(sc, BCM_BSC_DATA, *sc->sc_data++);
sc->sc_resid--;
status = BCM_BSC_READ(sc, BCM_BSC_STATUS);
}
}
if (status & BCM_BSC_STATUS_DONE) {
/* Disable interrupts. */
bcm_bsc_reset(sc);
wakeup(sc->sc_dev);
}
BCM_BSC_UNLOCK(sc);
}
static int
bcm_bsc_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
{
struct bcm_bsc_softc *sc;
uint32_t intr, read, status;
int i, err;
sc = device_get_softc(dev);
BCM_BSC_LOCK(sc);
/* If the controller is busy wait until it is available. */
while (sc->sc_flags & BCM_I2C_BUSY)
mtx_sleep(dev, &sc->sc_mtx, 0, "bscbusw", 0);
/* Now we have control over the BSC controller. */
sc->sc_flags = BCM_I2C_BUSY;
/* Clear the FIFO and the pending interrupts. */
bcm_bsc_reset(sc);
err = 0;
for (i = 0; i < nmsgs; i++) {
/* Write the slave address. */
BCM_BSC_WRITE(sc, BCM_BSC_SLAVE, msgs[i].slave >> 1);
/* Write the data length. */
BCM_BSC_WRITE(sc, BCM_BSC_DLEN, msgs[i].len);
sc->sc_data = msgs[i].buf;
sc->sc_resid = msgs[i].len;
if ((msgs[i].flags & IIC_M_RD) == 0) {
/* Fill up the TX FIFO. */
status = BCM_BSC_READ(sc, BCM_BSC_STATUS);
while (sc->sc_resid > 0 &&
(status & BCM_BSC_STATUS_TXD)) {
BCM_BSC_WRITE(sc, BCM_BSC_DATA, *sc->sc_data);
sc->sc_data++;
sc->sc_resid--;
status = BCM_BSC_READ(sc, BCM_BSC_STATUS);
}
read = 0;
intr = BCM_BSC_CTRL_INTT;
sc->sc_flags &= ~BCM_I2C_READ;
} else {
sc->sc_flags |= BCM_I2C_READ;
read = BCM_BSC_CTRL_READ;
intr = BCM_BSC_CTRL_INTR;
}
intr |= BCM_BSC_CTRL_INTD;
/* Start the transfer. */
BCM_BSC_WRITE(sc, BCM_BSC_CTRL, BCM_BSC_CTRL_I2CEN |
BCM_BSC_CTRL_ST | read | intr);
/* Wait for the transaction to complete. */
err = mtx_sleep(dev, &sc->sc_mtx, 0, "bsciow", hz);
/* Check for errors. */
if (err == 0 && (sc->sc_flags & BCM_I2C_ERROR))
err = EIO;
if (err != 0)
break;
}
/* Clean the controller flags. */
sc->sc_flags = 0;
/* Wake up the threads waiting for bus. */
wakeup(dev);
BCM_BSC_UNLOCK(sc);
return (err);
}
static int
bcm_bsc_iicbus_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
{
struct bcm_bsc_softc *sc;
uint32_t busfreq;
sc = device_get_softc(dev);
BCM_BSC_LOCK(sc);
bcm_bsc_reset(sc);
if (sc->sc_iicbus == NULL)
busfreq = 100000;
else
busfreq = IICBUS_GET_FREQUENCY(sc->sc_iicbus, speed);
BCM_BSC_WRITE(sc, BCM_BSC_CLOCK, BCM_BSC_CORE_CLK / busfreq);
BCM_BSC_UNLOCK(sc);
return (IIC_ENOADDR);
}
static phandle_t
bcm_bsc_get_node(device_t bus, device_t dev)
{
/* We only have one child, the I2C bus, which needs our own node. */
return (ofw_bus_get_node(bus));
}
static device_method_t bcm_bsc_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, bcm_bsc_probe),
DEVMETHOD(device_attach, bcm_bsc_attach),
DEVMETHOD(device_detach, bcm_bsc_detach),
/* iicbus interface */
DEVMETHOD(iicbus_reset, bcm_bsc_iicbus_reset),
DEVMETHOD(iicbus_callback, iicbus_null_callback),
DEVMETHOD(iicbus_transfer, bcm_bsc_transfer),
/* ofw_bus interface */
DEVMETHOD(ofw_bus_get_node, bcm_bsc_get_node),
DEVMETHOD_END
};
static devclass_t bcm_bsc_devclass;
static driver_t bcm_bsc_driver = {
"iichb",
bcm_bsc_methods,
sizeof(struct bcm_bsc_softc),
};
DRIVER_MODULE(iicbus, bcm2835_bsc, iicbus_driver, iicbus_devclass, 0, 0);
DRIVER_MODULE(bcm2835_bsc, simplebus, bcm_bsc_driver, bcm_bsc_devclass, 0, 0);