Differential D2956 Diff 6740 sys/dev/ow/owc_gpiobus.c

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sys/dev/ow/owc_gpiobus.c

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				/*-
				* Copyright (c) 2015 M. Warner Losh <imp@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 "opt_platform.h"

				#include <sys/param.h>
				#include <sys/systm.h>
				#include <sys/bus.h>
				#include <sys/gpio.h>
				#include <sys/kernel.h>
				#include <sys/lock.h>
				#include <sys/malloc.h>
				#include <sys/module.h>
				#include <sys/mutex.h>

				#ifdef FDT
				#include <dev/fdt/fdt_common.h>
				#include <dev/ofw/ofw_bus.h>
				#include <dev/ofw/ofw_bus_subr.h>
				#endif

				#include <dev/gpio/gpiobusvar.h>
				#include "gpiobus_if.h"

				#include <dev/ow/owll.h>

				#define OW_PIN 0

				#define OWC_GPIOBUS_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx)
				#define OWC_GPIOBUS_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx)
				#define OWC_GPIOBUS_LOCK_INIT(_sc) \
				loosUnsubmitted Not Done Inline Actions Check #define<tab> vs #define<space> occurrences. loos: Check #define<tab> vs #define<space> occurrences.
				mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->sc_dev), \
				"owc_gpiobus", MTX_DEF)
				#define OWC_GPIOBUS_LOCK_DESTROY(_sc) mtx_destroy(&_sc->sc_mtx);

				struct owc_gpiobus_softc
				{
				device_t sc_dev;
				device_t sc_busdev;
				struct mtx sc_mtx;
				};

				static int owc_gpiobus_probe(device_t);
				static int owc_gpiobus_attach(device_t);
				static int owc_gpiobus_detach(device_t);

				#ifdef FDT
				static void
				owc_gpiobus_identify(driver_t *driver, device_t bus)
				{
				phandle_t w1, root;

				/*
				* Find all the 1-wire bus pseudo-nodes that are
				* at the top level of the FDT. Would be nice to
				* somehow preserve the node name of these busses,
				* but there's no good place to put it. The driver's
				* name is used for the device name, and the 1-wire
				* bus overwrites the description.
				*/
				root = OF_finddevice("/");
				if (root == 0)
				return;
				for (w1 = OF_child(root); w1 != 0; w1 = OF_peer(w1)) {
				if (!fdt_is_compatible_strict(w1, "w1-gpio"))
				continue;
				if (!OF_hasprop(w1, "gpios"))
				continue;
				ofw_gpiobus_add_fdt_child(bus, driver->name, w1);
				}
				}
				#endif

				static int
				owc_gpiobus_probe(device_t dev)
				{
				#ifdef FDT
				if (!ofw_bus_status_okay(dev))
				return (ENXIO);

				if (ofw_bus_is_compatible(dev, "w1-gpio")) {
				device_set_desc(dev, "FDT GPIO attached one-wire bus");
				return (BUS_PROBE_DEFAULT);
				}

				return (ENXIO);
				#else
				device_set_desc(dev, "GPIO attached one-wire bus");
				return 0;
				#endif
				}

				static int
				owc_gpiobus_attach(device_t dev)
				{
				struct owc_gpiobus_softc *sc;
				device_t *kids;
				int nkid;

				sc = device_get_softc(dev);
				sc->sc_dev = dev;
				sc->sc_busdev = device_get_parent(dev);
				OWC_GPIOBUS_LOCK_INIT(sc);
				nkid = 0;
				if (device_get_children(dev, &kids, &nkid) == 0)
				free(kids, M_TEMP);
				if (nkid == 0)
				device_add_child(dev, "ow", -1);
				free(kids, M_TEMP);
				bus_generic_attach(dev);
				loosUnsubmitted Not Done Inline Actions Double free. The kids variable is already freed on line 132 (this line can be removed). loos: Double free. The kids variable is already freed on line 132 (this line can be removed).

				return (0);
				}

				static int
				owc_gpiobus_detach(device_t dev)
				{
				struct owc_gpiobus_softc *sc;

				sc = device_get_softc(dev);
				OWC_GPIOBUS_LOCK_DESTROY(sc);
				bus_generic_detach(dev);
				return (0);
				}

				/*
				* In the diagrams below, R is driven by the resitor pullup, M is driven by the
				* master, and S is driven by the slave / target.
				wblockUnsubmitted Done Inline Actions Typo: s/resitor/resistor/ wblock: Typo: s/resitor/resistor/
				*/

				/*
				* These macros let what why we're doing stuff shine in the code
				* below, and let the how be confined to here.
				*/
				#define GETBUS(sc) GPIOBUS_ACQUIRE_BUS((sc)->sc_busdev, \
				(sc)->sc_dev, GPIOBUS_WAIT)
				#define RELBUS(sc) GPIOBUS_RELEASE_BUS((sc)->sc_busdev, \
				(sc)->sc_dev)
				#define OUTPIN(sc) GPIOBUS_PIN_SETFLAGS((sc)->sc_busdev, \
				(sc)->sc_dev, OW_PIN, GPIO_PIN_OUTPUT)
				#define INPIN(sc) GPIOBUS_PIN_SETFLAGS((sc)->sc_busdev, \
				(sc)->sc_dev, OW_PIN, GPIO_PIN_INPUT)
				#define GETPIN(sc, bit) GPIOBUS_PIN_GET((sc)->sc_busdev, \
				(sc)->sc_dev, OW_PIN, bit)
				#define LOW(sc) GPIOBUS_PIN_SET((sc)->sc_busdev, \
				(sc)->sc_dev, OW_PIN, GPIO_PIN_LOW)

				/*
				* WRITE-ONE (see owll_if.m for timings) From Figure 4-1 AN-937
				*
				* \|<---------tSLOT---->\|<-tREC->\|
				* High RRRRM \| RRRRRRRRRRRR\|RRRRRRRRM
				* M \| R \| \| \| M
				* M\| R \| \| \| M
				* Low MMMMMMM \| \| \| MMMMMM...
				* \|<-tLOW1->\| \| \|
				* \|<------15us--->\| \|
				* \|<--------60us---->\|
				*/
				static int
				owc_gpiobus_write_one(device_t dev, struct ow_timing *t)
				{
				struct owc_gpiobus_softc *sc;
				int error;

				sc = device_get_softc(dev);
				error = GETBUS(sc);
				if (error != 0)
				return error;

				critical_enter();

				/* Force low */
				OUTPIN(sc);
				LOW(sc);
				DELAY(t->t_low1);

				/* Allow resister to float line high */
				INPIN(sc);
				DELAY(t->t_slot - t->t_low1 + t->t_rec);

				critical_exit();

				RELBUS(sc);

				return 0;
				}

				/*
				* WRITE-ZERO (see owll_if.m for timings) From Figure 4-2 AN-937
				*
				* \|<---------tSLOT------>\|<-tREC->\|
				* High RRRRM \| \| \|RRRRRRRM
				* M \| \| R M
				* M\| \| \| \|R M
				* Low MMMMMMMMMMMMMMMMMMMMMR MMMMMM...
				* \|<--15us->\| \| \|
				* \|<------60us--->\| \|
				* \|<-------tLOW0------>\|
				*/
				static int
				owc_gpiobus_write_zero(device_t dev, struct ow_timing *t)
				{
				struct owc_gpiobus_softc *sc;
				int error;

				sc = device_get_softc(dev);
				error = GETBUS(sc);
				if (error != 0)
				return error;

				critical_enter();

				/* Force low */
				OUTPIN(sc);
				LOW(sc);
				DELAY(t->t_low0);

				/* Allow resister to float line high */
				INPIN(sc);
				DELAY(t->t_slot - t->t_low0 + t->t_rec);

				critical_exit();

				RELBUS(sc);

				return 0;
				}

				/*
				* READ-DATA (see owll_if.m for timings) From Figure 4-3 AN-937
				*
				* \|<---------tSLOT------>\|<-tREC->\|
				* High RRRRM \| rrrrrrrrrrrrrrrRRRRRRRM
				* M \| r \| R M
				* M\| r \| \|R M
				* Low MMMMMMMSSSSSSSSSSSSSSR MMMMMM...
				* \|<tLOWR>< sample > \|
				* \|<------tRDV---->\| \|
				* ->\| \|<-tRELEASE
				*
				* r -- allowed to pull high via the resitor when slave writes a 1-bit
				*
				*/
				static int
				owc_gpiobus_read_data(device_t dev, struct ow_timing t, int bit)
				{
				struct owc_gpiobus_softc *sc;
				int error;

				sc = device_get_softc(dev);
				error = GETBUS(sc);
				if (error != 0)
				return error;

				critical_enter();

				/* Force low */
				OUTPIN(sc);
				LOW(sc);
				DELAY(t->t_lowr);

				/* Allow resister to float line high or not */
				INPIN(sc);
				DELAY(t->t_rdv - t->t_lowr - 3);

				loosUnsubmitted Not Done Inline Actions Reducing this delay to (t->t_rdv / 4) seems to help with CRC errors (but not enough to eliminate them). loos: Reducing this delay to (t->t_rdv / 4) seems to help with CRC errors (but not enough to…
				/* Read */
				GETPIN(sc, bit);
				DELAY(t->t_slot);

				critical_exit();

				RELBUS(sc);

				return 0;
				}

				/*
				* RESET AND PRESENCE PULSE (see owll_if.m for timings) From Figure 4-4 AN-937
				*
				* \|<---------tRSTH------------>\|
				* High RRRM \| \| RRRRRRRS \| RRRR RRM
				* M \| \|R\| \|S \| R M
				* M\| R \| \| S \|R M
				* Low MMMMMMMM MMMMMM\| \| \| SSSSSSSSSS MMMMMM
				* \|<----tRSTL--->\| \| \|<-tPDL---->\|
				* \| ->\| \|<-tR \| \|
				* \|<tPDH>\|
				*
				* Note: for Regular Speed operations, tRSTL + tR should be less than 960us to
				* avoid interferring with other devives on the bus
				*/
				wblockUnsubmitted Done Inline Actions Typo: s/devives/devices/ wblock: Typo: s/devives/devices/
				wblockUnsubmitted Not Done Inline Actions Typo: s/interferring/interfering/ wblock: Typo: s/interferring/interfering/
				static int
				owc_gpiobus_reset_and_presence(device_t dev, struct ow_timing t, int bit)
				{
				struct owc_gpiobus_softc *sc;
				int error;
				int buf = -1;

				sc = device_get_softc(dev);
				error = GETBUS(sc);
				if (error != 0)
				return error;


				critical_enter();
				loosUnsubmitted Not Done Inline Actions extra blank line. loos: extra blank line.

				/* Force low */
				OUTPIN(sc);
				LOW(sc);
				DELAY(t->t_rstl);

				/* Allow resister to float line high and then wait for reset pulse */
				INPIN(sc);
				wblockUnsubmitted Done Inline Actions Typo: s/resister/resistor/ wblock: Typo: s/resister/resistor/
				DELAY(t->t_pdh + 5);

				/* Read presence pulse */
				GETPIN(sc, &buf);

				critical_exit();

				DELAY(t->t_rsth - (t->t_pdh + 5)); /* Timing not critical for this one */

				*bit = !!buf;

				RELBUS(sc);

				return 0;
				}

				static devclass_t owc_gpiobus_devclass;

				static device_method_t owc_gpiobus_methods[] = {
				/* Device interface */
				#ifdef FDT
				DEVMETHOD(device_identify, owc_gpiobus_identify),
				#endif
				DEVMETHOD(device_probe, owc_gpiobus_probe),
				DEVMETHOD(device_attach, owc_gpiobus_attach),
				DEVMETHOD(device_detach, owc_gpiobus_detach),

				DEVMETHOD(owll_write_one, owc_gpiobus_write_one),
				DEVMETHOD(owll_write_zero, owc_gpiobus_write_zero),
				DEVMETHOD(owll_read_data, owc_gpiobus_read_data),
				DEVMETHOD(owll_reset_and_presence, owc_gpiobus_reset_and_presence),
				{ 0, 0 }
				};

				static driver_t owc_gpiobus_driver = {
				"owc",
				owc_gpiobus_methods,
				sizeof(struct owc_gpiobus_softc),
				};

				DRIVER_MODULE(owc_gpiobus_fdt, gpiobus, owc_gpiobus_driver, owc_gpiobus_devclass, 0, 0);
				MODULE_DEPEND(owc_gpiobus_fdt, ow, 1, 1, 1);