Differential D5749 Diff 14821 head/sys/dev/uart/uart_dev_snps.c

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head/sys/dev/uart/uart_dev_snps.c

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				/*-
				* 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, "baudclk", baudclk) != 0 &&
				clk_get_by_ofw_index(dev, 0, baudclk) != 0)
				return (ENOENT);

				/* APB peripheral clock is optional */
				(void)clk_get_by_ofw_name(dev, "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, &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);