Author: ian Date: Tue Dec 17 15:56:48 2019 New Revision: 355858 URL: https://svnweb.freebsd.org/changeset/base/355858
Log: Update owc_gpiobus (one-wire over gpio) to the modern gpio_pin interface. It used to be required that a device be a child of gpiobus(4) to manipulate gpio pins. That requirement didn't work well for FDT-based systems with many cross-hierarchy users of gpio, so a more modern framework was created that removed the old hierarchy requirement. These changes adapt the owc_gpiobus driver to use the newer gpio_pin_* functions to acquire, release, and manipulate gpio pins. This allows a single driver to work for both hinted-attachment and fdt-based systems, and removes the requirement that any one-wire fdt nodes must appear at the root of the devicetree. Differential Revision: https://reviews.freebsd.org/D22710 Modified: head/sys/dev/ow/owc_gpiobus.c Modified: head/sys/dev/ow/owc_gpiobus.c ============================================================================== --- head/sys/dev/ow/owc_gpiobus.c Tue Dec 17 15:03:51 2019 (r355857) +++ head/sys/dev/ow/owc_gpiobus.c Tue Dec 17 15:56:48 2019 (r355858) @@ -38,17 +38,21 @@ __FBSDID("$FreeBSD$"); #include <sys/module.h> #include <sys/mutex.h> +#include <dev/gpio/gpiobusvar.h> +#include <dev/ow/owll.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" +static struct ofw_compat_data compat_data[] = { + {"w1-gpio", true}, + {NULL, false} +}; +OFWBUS_PNP_INFO(compat_data); +SIMPLEBUS_PNP_INFO(compat_data); +#endif /* FDT */ -#include <dev/ow/owll.h> - #define OW_PIN 0 #define OWC_GPIOBUS_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx) @@ -61,7 +65,7 @@ __FBSDID("$FreeBSD$"); struct owc_gpiobus_softc { device_t sc_dev; - device_t sc_busdev; + gpio_pin_t sc_pin; struct mtx sc_mtx; }; @@ -69,68 +73,69 @@ 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) +static int +owc_gpiobus_probe(device_t dev) { - phandle_t w1, root; + int rv; /* - * 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. + * By default we only bid to attach if specifically added by our parent + * (usually via hint.owc_gpiobus.#.at=busname). On FDT systems we bid + * as the default driver based on being configured in the FDT data. */ - root = OF_finddevice("/"); - if (root == -1) - 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 + rv = BUS_PROBE_NOWILDCARD; -static int -owc_gpiobus_probe(device_t dev) -{ #ifdef FDT - if (!ofw_bus_status_okay(dev)) - return (ENXIO); + if (ofw_bus_status_okay(dev) && + ofw_bus_search_compatible(dev, compat_data)->ocd_data) + rv = BUS_PROBE_DEFAULT; +#endif - if (ofw_bus_is_compatible(dev, "w1-gpio")) { - device_set_desc(dev, "FDT GPIO attached one-wire bus"); - return (BUS_PROBE_DEFAULT); - } + device_set_desc(dev, "GPIO one-wire bus"); - return (ENXIO); -#else - device_set_desc(dev, "GPIO attached one-wire bus"); - return 0; -#endif + return (rv); } static int owc_gpiobus_attach(device_t dev) { struct owc_gpiobus_softc *sc; - device_t *kids; - int nkid; + int err; sc = device_get_softc(dev); sc->sc_dev = dev; - sc->sc_busdev = device_get_parent(dev); + +#ifdef FDT + /* Try to configure our pin from fdt data on fdt-based systems. */ + err = gpio_pin_get_by_ofw_idx(dev, ofw_bus_get_node(dev), OW_PIN, + &sc->sc_pin); +#else + err = ENOENT; +#endif + /* + * If we didn't get configured by fdt data and our parent is gpiobus, + * see if we can be configured by the bus (allows hinted attachment even + * on fdt-based systems). + */ + if (err != 0 && + strcmp("gpiobus", device_get_name(device_get_parent(dev))) == 0) + err = gpio_pin_get_by_child_index(dev, OW_PIN, &sc->sc_pin); + + /* If we didn't get configured by either method, whine and punt. */ + if (err != 0) { + device_printf(sc->sc_dev, + "cannot acquire gpio pin (config error)\n"); + return (err); + } + 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); + + /* + * Add the ow bus as a child, but defer probing and attaching it until + * interrupts work, because we can't do IO for them until we can read + * the system timecounter (which initializes after device attachments). + */ + device_add_child(sc->sc_dev, "ow", -1); return (bus_delayed_attach_children(dev)); } @@ -138,10 +143,16 @@ static int owc_gpiobus_detach(device_t dev) { struct owc_gpiobus_softc *sc; + int err; sc = device_get_softc(dev); + + if ((err = device_delete_children(dev)) != 0) + return (err); + + gpio_pin_release(sc->sc_pin); OWC_GPIOBUS_LOCK_DESTROY(sc); - bus_generic_detach(dev); + return (0); } @@ -154,18 +165,10 @@ owc_gpiobus_detach(device_t dev) * 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) +#define OUTPIN(sc) gpio_pin_setflags((sc)->sc_pin, GPIO_PIN_OUTPUT) +#define INPIN(sc) gpio_pin_setflags((sc)->sc_pin, GPIO_PIN_INPUT) +#define GETPIN(sc, bp) gpio_pin_is_active((sc)->sc_pin, (bp)) +#define LOW(sc) gpio_pin_set_active((sc)->sc_pin, false) /* * WRITE-ONE (see owll_if.m for timings) From Figure 4-1 AN-937 @@ -183,12 +186,8 @@ 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(); @@ -203,8 +202,6 @@ owc_gpiobus_write_one(device_t dev, struct ow_timing * critical_exit(); - RELBUS(sc); - return (0); } @@ -224,12 +221,8 @@ 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(); @@ -244,8 +237,6 @@ owc_gpiobus_write_zero(device_t dev, struct ow_timing critical_exit(); - RELBUS(sc); - return (0); } @@ -268,13 +259,10 @@ static int owc_gpiobus_read_data(device_t dev, struct ow_timing *t, int *bit) { struct owc_gpiobus_softc *sc; - int error, sample; + bool sample; sbintime_t then, now; sc = device_get_softc(dev); - error = GETBUS(sc); - if (error != 0) - return (error); critical_enter(); @@ -293,7 +281,7 @@ owc_gpiobus_read_data(device_t dev, struct ow_timing * do { now = sbinuptime(); GETPIN(sc, &sample); - } while (now - then < (t->t_rdv + 2) * SBT_1US && sample == 0); + } while (now - then < (t->t_rdv + 2) * SBT_1US && sample == false); critical_exit(); if (now - then < t->t_rdv * SBT_1US) @@ -306,9 +294,7 @@ owc_gpiobus_read_data(device_t dev, struct ow_timing * now = sbinuptime(); } while (now - then < (t->t_slot + t->t_rec) * SBT_1US); - RELBUS(sc); - - return (error); + return (0); } /* @@ -324,32 +310,31 @@ owc_gpiobus_read_data(device_t dev, struct ow_timing * * |<tPDH>| * * Note: for Regular Speed operations, tRSTL + tR should be less than 960us to - * avoid interferring with other devices on the bus + * avoid interfering with other devices on the bus. + * + * Return values in *bit: + * -1 = Bus wiring error (stuck low). + * 0 = no presence pulse + * 1 = presence pulse detected */ 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; + bool sample; sc = device_get_softc(dev); - error = GETBUS(sc); - if (error != 0) - return (error); /* * Read the current state of the bus. The steady state of an idle bus is * high. Badly wired buses that are missing the required pull up, or * that have a short circuit to ground cause all kinds of mischief when - * we try to read them later. Return EIO and release the bus if the bus - * is currently low. + * we try to read them later. Return EIO if the bus is currently low. */ INPIN(sc); - GETPIN(sc, &buf); - if (buf == 0) { + GETPIN(sc, &sample); + if (sample == false) { *bit = -1; - RELBUS(sc); return (EIO); } @@ -365,8 +350,8 @@ owc_gpiobus_reset_and_presence(device_t dev, struct ow DELAY(t->t_pdh + t->t_pdl / 2); /* Read presence pulse */ - GETPIN(sc, &buf); - *bit = !!buf; + GETPIN(sc, &sample); + *bit = sample; critical_exit(); @@ -377,15 +362,12 @@ owc_gpiobus_reset_and_presence(device_t dev, struct ow * window. It should return to high. If it is low, then we have some * problem and should abort the reset. */ - GETPIN(sc, &buf); - if (buf == 0) { + GETPIN(sc, &sample); + if (sample == false) { *bit = -1; - RELBUS(sc); return (EIO); } - RELBUS(sc); - return (0); } @@ -393,9 +375,6 @@ 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), @@ -412,6 +391,10 @@ static driver_t owc_gpiobus_driver = { owc_gpiobus_methods, sizeof(struct owc_gpiobus_softc), }; + +#ifdef FDT +DRIVER_MODULE(owc_gpiobus, simplebus, owc_gpiobus_driver, owc_gpiobus_devclass, 0, 0); +#endif DRIVER_MODULE(owc_gpiobus, gpiobus, owc_gpiobus_driver, owc_gpiobus_devclass, 0, 0); MODULE_DEPEND(owc_gpiobus, ow, 1, 1, 1); _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
