freebsd-dev/sys/dev/uart/uart_dev_ti8250.c
Ian Lepore aef60d8c4a Add support for uarts other than the serial console in TI OMAP SoCs.
The TI uart hardware is ns16550-compatible, except that before it can
be used the clocks and power have to be enabled and a non-standard
mode control register has to be set to put the device in uart mode
(as opposed to irDa or other serial protocols).  This adds the extra
code in an extension to the standard ns8250 probe routine, and the
rest of the driver is just the standard ns8250 code.
2013-08-21 14:33:02 +00:00

142 lines
4.3 KiB
C

/*-
* Copyright (c) 2013 Ian Lepore
* 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.
*/
#include "opt_platform.h"
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <machine/bus.h>
#include <arm/ti/ti_prcm.h>
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/uart/uart.h>
#include <dev/uart/uart_cpu.h>
#include <dev/uart/uart_bus.h>
#include <dev/uart/uart_dev_ns8250.h>
#include "uart_if.h"
/*
* High-level UART interface.
*/
struct ti8250_softc {
struct ns8250_softc ns8250_base;
/*uint32_t mystuff;*/
};
#define MDR1_REG 8
#define MDR1_MODE_UART 0
#define MDR1_MODE_DISABLE 7
#define SYSCC_REG 15
#define SYSCC_SOFTRESET (1 << 1)
#define SYSS_REG 16
#define SYSS_STATUS_RESETDONE (1 << 0)
static int
ti8250_bus_probe(struct uart_softc *sc)
{
int status;
int devid;
clk_ident_t clkid;
pcell_t prop;
phandle_t node;
/*
* Get the device id from FDT. If it's not there we can't turn on the
* right clocks, so bail, unless we're doing unit 0. We assume that's
* the serial console, whose clock isn't controllable anyway, and we
* sure don't want to break the console because of a config error.
*/
node = ofw_bus_get_node(sc->sc_dev);
if ((OF_getprop(node, "uart-device-id", &prop, sizeof(prop))) <= 0) {
device_printf(sc->sc_dev,
"missing uart-device-id attribute in FDT\n");
if (device_get_unit(sc->sc_dev) != 0)
return (ENXIO);
devid = 0;
} else
devid = fdt32_to_cpu(prop);
/* Enable clocks for this device. We can't continue if that fails. */
clkid = UART0_CLK + devid;
if ((status = ti_prcm_clk_enable(clkid)) != 0)
return (status);
/*
* Set the hardware to disabled mode, do a full device reset, then set
* it to uart mode. Most devices will be reset-and-disabled already,
* but you never know what a bootloader might have done.
*/
uart_setreg(&sc->sc_bas, MDR1_REG, MDR1_MODE_DISABLE);
uart_setreg(&sc->sc_bas, SYSCC_REG, SYSCC_SOFTRESET);
while (uart_getreg(&sc->sc_bas, SYSS_REG) & SYSS_STATUS_RESETDONE)
continue;
uart_setreg(&sc->sc_bas, MDR1_REG, MDR1_MODE_UART);
status = ns8250_bus_probe(sc);
if (status == 0)
device_set_desc(sc->sc_dev, "TI UART (16550 compatible)");
return (status);
}
static kobj_method_t ti8250_methods[] = {
KOBJMETHOD(uart_probe, ti8250_bus_probe),
KOBJMETHOD(uart_attach, ns8250_bus_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_END
};
struct uart_class uart_ti8250_class = {
"ti8250",
ti8250_methods,
sizeof(struct ti8250_softc),
.uc_ops = &uart_ns8250_ops,
.uc_range = 0x88,
.uc_rclk = 48000000
};