freebsd-dev/sys/dev/uart/uart_dev_snps.c
Michal Meloun dac935533b EXTRES: Add OF node as argument to all <foo>_get_by_ofw_<bar>() functions.
In some cases, the driver must handle given properties located in
specific OF subnode. Instead of creating duplicate set of function, add
'node' as argument to existing functions, defaulting it to device OF node.

MFC after: 3 weeks
2016-07-10 18:28:15 +00:00

284 lines
6.8 KiB
C

/*-
* Copyright (c) 2016 Jared McNeill <jmcneill@invisible.ca>
* 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 ``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 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.
*
* $FreeBSD$
*/
#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 <machine/bus.h>
#include <dev/uart/uart.h>
#include <dev/uart/uart_bus.h>
#include <dev/uart/uart_cpu_fdt.h>
#include <dev/uart/uart_dev_ns8250.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#ifdef EXT_RESOURCES
#include <dev/extres/clk/clk.h>
#include <dev/extres/hwreset/hwreset.h>
#endif
#include "uart_if.h"
struct snps_softc {
struct ns8250_softc ns8250;
#ifdef EXT_RESOURCES
clk_t baudclk;
clk_t apb_pclk;
hwreset_t reset;
#endif
};
static int
snps_uart_attach(struct uart_softc *uart_sc)
{
struct snps_softc *sc;
sc = (struct snps_softc *)uart_sc;
/* UART requires to read USR reg when IIR_BUSY */
sc->ns8250.busy_detect = 1;
return (ns8250_bus_attach(uart_sc));
}
static kobj_method_t snps_methods[] = {
KOBJMETHOD(uart_probe, ns8250_bus_probe),
KOBJMETHOD(uart_attach, snps_uart_attach),
KOBJMETHOD(uart_detach, ns8250_bus_detach),
KOBJMETHOD(uart_flush, ns8250_bus_flush),
KOBJMETHOD(uart_getsig, ns8250_bus_getsig),
KOBJMETHOD(uart_ioctl, ns8250_bus_ioctl),
KOBJMETHOD(uart_ipend, ns8250_bus_ipend),
KOBJMETHOD(uart_param, ns8250_bus_param),
KOBJMETHOD(uart_receive, ns8250_bus_receive),
KOBJMETHOD(uart_setsig, ns8250_bus_setsig),
KOBJMETHOD(uart_transmit, ns8250_bus_transmit),
KOBJMETHOD(uart_grab, ns8250_bus_grab),
KOBJMETHOD(uart_ungrab, ns8250_bus_ungrab),
KOBJMETHOD_END
};
struct uart_class uart_snps_class = {
"snps",
snps_methods,
sizeof(struct snps_softc),
.uc_ops = &uart_ns8250_ops,
.uc_range = 8,
.uc_rclk = 0,
};
static struct ofw_compat_data compat_data[] = {
{ "snps,dw-apb-uart", (uintptr_t)&uart_snps_class },
{ NULL, (uintptr_t)NULL }
};
UART_FDT_CLASS(compat_data);
#ifdef EXT_RESOURCES
static int
snps_get_clocks(device_t dev, clk_t *baudclk, clk_t *apb_pclk)
{
struct snps_softc *sc;
sc = device_get_softc(dev);
*baudclk = NULL;
*apb_pclk = NULL;
/* Baud clock is either named "baudclk", or there is a single
* unnamed clock.
*/
if (clk_get_by_ofw_name(dev, 0, "baudclk", baudclk) != 0 &&
clk_get_by_ofw_index(dev, 0, 0, baudclk) != 0)
return (ENOENT);
/* APB peripheral clock is optional */
(void)clk_get_by_ofw_name(dev, 0, "apb_pclk", apb_pclk);
return (0);
}
#endif
static int
snps_probe(device_t dev)
{
struct snps_softc *sc;
struct uart_class *uart_class;
phandle_t node;
uint32_t shift, clock;
uint64_t freq;
int error;
#ifdef EXT_RESOURCES
clk_t baudclk, apb_pclk;
hwreset_t reset;
#endif
if (!ofw_bus_status_okay(dev))
return (ENXIO);
uart_class = (struct uart_class *)ofw_bus_search_compatible(dev,
compat_data)->ocd_data;
if (uart_class == NULL)
return (ENXIO);
freq = 0;
sc = device_get_softc(dev);
sc->ns8250.base.sc_class = uart_class;
node = ofw_bus_get_node(dev);
if (OF_getencprop(node, "reg-shift", &shift, sizeof(shift)) <= 0)
shift = 0;
if (OF_getencprop(node, "clock-frequency", &clock, sizeof(clock)) <= 0)
clock = 0;
#ifdef EXT_RESOURCES
if (hwreset_get_by_ofw_idx(dev, 0, 0, &reset) == 0) {
error = hwreset_deassert(reset);
if (error != 0) {
device_printf(dev, "cannot de-assert reset\n");
return (error);
}
}
if (snps_get_clocks(dev, &baudclk, &apb_pclk) == 0) {
error = clk_enable(baudclk);
if (error != 0) {
device_printf(dev, "cannot enable baud clock\n");
return (error);
}
if (apb_pclk != NULL) {
error = clk_enable(apb_pclk);
if (error != 0) {
device_printf(dev,
"cannot enable peripheral clock\n");
return (error);
}
}
if (clock == 0) {
error = clk_get_freq(baudclk, &freq);
if (error != 0) {
device_printf(dev, "cannot get frequency\n");
return (error);
}
clock = (uint32_t)freq;
}
}
#endif
if (bootverbose && clock == 0)
device_printf(dev, "could not determine frequency\n");
error = uart_bus_probe(dev, (int)shift, (int)clock, 0, 0);
if (error != 0)
return (error);
#ifdef EXT_RESOURCES
/* XXX uart_bus_probe has changed the softc, so refresh it */
sc = device_get_softc(dev);
/* Store clock and reset handles for detach */
sc->baudclk = baudclk;
sc->apb_pclk = apb_pclk;
sc->reset = reset;
#endif
return (0);
}
static int
snps_detach(device_t dev)
{
#ifdef EXT_RESOURCES
struct snps_softc *sc;
clk_t baudclk, apb_pclk;
hwreset_t reset;
#endif
int error;
#ifdef EXT_RESOURCES
sc = device_get_softc(dev);
baudclk = sc->baudclk;
apb_pclk = sc->apb_pclk;
reset = sc->reset;
#endif
error = uart_bus_detach(dev);
if (error != 0)
return (error);
#ifdef EXT_RESOURCES
if (reset != NULL) {
error = hwreset_assert(reset);
if (error != 0) {
device_printf(dev, "cannot assert reset\n");
return (error);
}
hwreset_release(reset);
}
if (apb_pclk != NULL) {
error = clk_release(apb_pclk);
if (error != 0) {
device_printf(dev, "cannot release peripheral clock\n");
return (error);
}
}
if (baudclk != NULL) {
error = clk_release(baudclk);
if (error != 0) {
device_printf(dev, "cannot release baud clock\n");
return (error);
}
}
#endif
return (0);
}
static device_method_t snps_bus_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, snps_probe),
DEVMETHOD(device_attach, uart_bus_attach),
DEVMETHOD(device_detach, snps_detach),
DEVMETHOD_END
};
static driver_t snps_uart_driver = {
uart_driver_name,
snps_bus_methods,
sizeof(struct snps_softc)
};
DRIVER_MODULE(uart_snps, simplebus, snps_uart_driver, uart_devclass, 0, 0);