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gpiobus: provide a new hint, pin_list

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"pin_list" allows to specify child pins as a list of pin numbers.
Existing hint "pins" serves the same purpose but with a 32-bit wide bit
mask.  One problem with that is that a controller can have more than 32
pins.  One example is amdgpio.  Also, a list of numbers is a little bit
more human friendly than a matching bit mask.  As a side note, it seems
that in FDT pins are typically specified by their numbers as well.

This commit also adds accessors for instance variables (IVARs) that
define the child pins.  My primary goal is to allow a child to be
configured programmatically rather than via hints (assuming that FDT is
not supported on a platform).  Also, while a child should not care about
specific pin numbers that are allocated to it, it could be interested in
how many were actually assigned to it.

While there, I removed "flags" instance variable.  It was unused.

Reviewed by:	mizhka
MFC after:	2 weeks
Differential Revision: https://reviews.freebsd.org/D20459
This commit is contained in:
Andriy Gapon 2019-06-27 15:46:06 +00:00
parent d55fcc487e
commit 061b38cdcc
3 changed files with 189 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
share/man/man4/gpio.4
View File

@ -24,7 +24,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd June 26, 2019
.Dd June 27, 2019
.Dt GPIO 4
.Os
.Sh NAME
@ -109,7 +109,7 @@ based system these hints can be used to configure drivers for devices
attached to
.Nm
pins:
.Bl -tag -width ".Va hint.driver.unit.pins"
.Bl -tag -width ".Va hint.driver.unit.pin_list"
.It Va hint.driver.unit.at
The
.Nm gpiobus
@ -125,6 +125,20 @@ This is a bitmask of the pins on the
.Nm gpiobus
that are connected to the device.
The pins will be allocated to the specified driver instance.
Only pins with numbers from 0 to 31 can be specified using this hint.
.It Va hint.driver.unit.pin_list
This is a list of pin numbers of pins on the
.Nm gpiobus
that are connected to the device.
The pins will be allocated to the specified driver instance.
This is a more user friendly alternative to the
.Ar pins
hint.
Additionally, this hint allows specifying pin numbers greater than 31.
The numbers can be decimal or hexadecimal with 0x prefix.
Any non-digit character can be used as a separator.
For example, it can be a comma, a slash or a space.
The separator can be followed by any number of space characters.
.El
.Pp
The following

185
sys/dev/gpio/gpiobus.c
View File

@ -255,13 +255,6 @@ gpiobus_alloc_ivars(struct gpiobus_ivar *devi)
M_NOWAIT | M_ZERO);
if (devi->pins == NULL)
return (ENOMEM);
devi->flags = malloc(sizeof(uint32_t) * devi->npins, M_DEVBUF,
M_NOWAIT | M_ZERO);
if (devi->flags == NULL) {
free(devi->pins, M_DEVBUF);
return (ENOMEM);
}
return (0);
}
@ -269,14 +262,11 @@ void
gpiobus_free_ivars(struct gpiobus_ivar *devi)
{
if (devi->flags) {
free(devi->flags, M_DEVBUF);
devi->flags = NULL;
}
if (devi->pins) {
free(devi->pins, M_DEVBUF);
devi->pins = NULL;
}
devi->npins = 0;
}
int
@ -325,6 +315,34 @@ gpiobus_release_pin(device_t bus, uint32_t pin)
return (0);
}
static int
gpiobus_acquire_child_pins(device_t dev, device_t child)
{
struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
int i;
for (i = 0; i < devi->npins; i++) {
/* Reserve the GPIO pin. */
if (gpiobus_acquire_pin(dev, devi->pins[i]) != 0) {
device_printf(child, "cannot acquire pin %d\n",
devi->pins[i]);
while (--i >= 0) {
(void)gpiobus_release_pin(dev,
devi->pins[i]);
}
gpiobus_free_ivars(devi);
return (EBUSY);
}
}
for (i = 0; i < devi->npins; i++) {
/* Use the child name as pin name. */
GPIOBUS_PIN_SETNAME(dev, devi->pins[i],
device_get_nameunit(child));
}
return (0);
}
static int
gpiobus_parse_pins(struct gpiobus_softc *sc, device_t child, int mask)
{
@ -349,17 +367,66 @@ gpiobus_parse_pins(struct gpiobus_softc *sc, device_t child, int mask)
for (i = 0; i < 32; i++) {
if ((mask & (1 << i)) == 0)
continue;
/* Reserve the GPIO pin. */
if (gpiobus_acquire_pin(sc->sc_busdev, i) != 0) {
gpiobus_free_ivars(devi);
return (EINVAL);
}
devi->pins[npins++] = i;
/* Use the child name as pin name. */
GPIOBUS_PIN_SETNAME(sc->sc_busdev, i,
device_get_nameunit(child));
}
if (gpiobus_acquire_child_pins(sc->sc_busdev, child) != 0)
return (EINVAL);
return (0);
}
static int
gpiobus_parse_pin_list(struct gpiobus_softc *sc, device_t child,
const char *pins)
{
struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
const char *p;
char *endp;
unsigned long pin;
int i, npins;
npins = 0;
p = pins;
for (;;) {
pin = strtoul(p, &endp, 0);
if (endp == p)
break;
npins++;
if (*endp == '\0')
break;
p = endp + 1;
}
if (*endp != '\0') {
device_printf(child, "garbage in the pin list: %s\n", endp);
return (EINVAL);
}
if (npins == 0) {
device_printf(child, "empty pin list\n");
return (EINVAL);
}
devi->npins = npins;
if (gpiobus_alloc_ivars(devi) != 0) {
device_printf(child, "cannot allocate device ivars\n");
return (EINVAL);
}
i = 0;
p = pins;
for (;;) {
pin = strtoul(p, &endp, 0);
devi->pins[i] = pin;
if (*endp == '\0')
break;
i++;
p = endp + 1;
}
if (gpiobus_acquire_child_pins(sc->sc_busdev, child) != 0)
return (EINVAL);
return (0);
}
@ -539,15 +606,26 @@ gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
struct gpiobus_softc *sc = GPIOBUS_SOFTC(bus);
struct gpiobus_ivar *devi;
device_t child;
int irq, pins;
const char *pins;
int irq, pinmask;
child = BUS_ADD_CHILD(bus, 0, dname, dunit);
devi = GPIOBUS_IVAR(child);
resource_int_value(dname, dunit, "pins", &pins);
if (gpiobus_parse_pins(sc, child, pins)) {
resource_list_free(&devi->rl);
free(devi, M_DEVBUF);
device_delete_child(bus, child);
if (resource_int_value(dname, dunit, "pins", &pinmask) == 0) {
if (gpiobus_parse_pins(sc, child, pinmask)) {
resource_list_free(&devi->rl);
free(devi, M_DEVBUF);
device_delete_child(bus, child);
return;
}
}
else if (resource_string_value(dname, dunit, "pin_list", &pins) == 0) {
if (gpiobus_parse_pin_list(sc, child, pins)) {
resource_list_free(&devi->rl);
free(devi, M_DEVBUF);
device_delete_child(bus, child);
return;
}
}
if (resource_int_value(dname, dunit, "irq", &irq) == 0) {
if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0)
@ -574,6 +652,61 @@ gpiobus_set_resource(device_t dev, device_t child, int type, int rid,
return (0);
}
static int
gpiobus_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
{
struct gpiobus_ivar *devi;
devi = GPIOBUS_IVAR(child);
switch (which) {
case GPIOBUS_IVAR_NPINS:
*result = devi->npins;
break;
case GPIOBUS_IVAR_PINS:
/* Children do not ever need to directly examine this. */
return (ENOTSUP);
default:
return (ENOENT);
}
return (0);
}
static int
gpiobus_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
{
struct gpiobus_ivar *devi;
const uint32_t *ptr;
int i;
devi = GPIOBUS_IVAR(child);
switch (which) {
case GPIOBUS_IVAR_NPINS:
/* GPIO ivars are set once. */
if (devi->npins != 0) {
return (EBUSY);
}
devi->npins = value;
if (gpiobus_alloc_ivars(devi) != 0) {
device_printf(child, "cannot allocate device ivars\n");
devi->npins = 0;
return (ENOMEM);
}
break;
case GPIOBUS_IVAR_PINS:
ptr = (const uint32_t *)value;
for (i = 0; i < devi->npins; i++)
devi->pins[i] = ptr[i];
if (gpiobus_acquire_child_pins(dev, child) != 0)
return (EBUSY);
break;
default:
return (ENOENT);
}
return (0);
}
static struct resource *
gpiobus_alloc_resource(device_t bus, device_t child, int type, int *rid,
rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
@ -833,6 +966,8 @@ static device_method_t gpiobus_methods[] = {
DEVMETHOD(bus_child_pnpinfo_str, gpiobus_child_pnpinfo_str),
DEVMETHOD(bus_child_location_str, gpiobus_child_location_str),
DEVMETHOD(bus_hinted_child, gpiobus_hinted_child),
DEVMETHOD(bus_read_ivar, gpiobus_read_ivar),
DEVMETHOD(bus_write_ivar, gpiobus_write_ivar),
/* GPIO protocol */
DEVMETHOD(gpiobus_acquire_bus, gpiobus_acquire_bus),

14
sys/dev/gpio/gpiobusvar.h
View File

@ -107,10 +107,22 @@ struct gpiobus_ivar
{
struct resource_list rl; /* isr resource list */
uint32_t npins; /* pins total */
uint32_t *flags; /* pins flags */
uint32_t *pins; /* pins map */
};
enum gpiobus_ivars {
GPIOBUS_IVAR_NPINS = 10500,
GPIOBUS_IVAR_PINS,
};
#define GPIOBUS_ACCESSOR(var, ivar, type) \
__BUS_ACCESSOR(gpiobus, var, GPIOBUS, ivar, type)
GPIOBUS_ACCESSOR(npins, NPINS, uint32_t)
GPIOBUS_ACCESSOR(pins, PINS, const uint32_t *)
#undef GPIOBUS_ACCESSOR
#ifdef FDT
struct ofw_gpiobus_devinfo {
struct gpiobus_ivar opd_dinfo;