[src/thorpej-i2c-spi-conf]: src/sys/dev/spi If we were attached via FDT, chec...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/640f30336828
branches:  thorpej-i2c-spi-conf
changeset: 983394:640f30336828
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Wed May 19 14:17:08 2021 +0000

description:
If we were attached via FDT, check for a "dc-gpios" property and,
if present, use the specified GPIO pin for 4-wire mode.

diffstat:

 sys/dev/spi/ssdfb_spi.c |  55 ++++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 50 insertions(+), 5 deletions(-)

diffs (118 lines):

diff -r d4a84ec6a5fd -r 640f30336828 sys/dev/spi/ssdfb_spi.c
--- a/sys/dev/spi/ssdfb_spi.c   Wed May 19 13:40:56 2021 +0000
+++ b/sys/dev/spi/ssdfb_spi.c   Wed May 19 14:17:08 2021 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: ssdfb_spi.c,v 1.5.4.1 2021/05/19 03:46:26 thorpej Exp $ */
+/* $NetBSD: ssdfb_spi.c,v 1.5.4.2 2021/05/19 14:17:08 thorpej Exp $ */
 
 /*
  * Copyright (c) 2019 The NetBSD Foundation, Inc.
@@ -30,13 +30,20 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ssdfb_spi.c,v 1.5.4.1 2021/05/19 03:46:26 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ssdfb_spi.c,v 1.5.4.2 2021/05/19 14:17:08 thorpej Exp $");
+
+#include "opt_fdt.h"
 
 #include <sys/param.h>
 #include <sys/device.h>
 #include <sys/kernel.h>
 #include <dev/wscons/wsdisplayvar.h>
 #include <dev/rasops/rasops.h>
+
+#ifdef FDT
+#include <dev/fdt/fdtvar.h>
+#endif /* FDT */
+
 #include <dev/spi/spivar.h>
 #include <dev/ic/ssdfbvar.h>
 
@@ -49,6 +56,9 @@
 struct ssdfb_spi_softc {
        struct ssdfb_softc      sc;
        struct spi_handle       *sc_sh;
+#ifdef FDT
+       struct fdtbus_gpio_pin *sc_dc_gpio;
+#endif /* FDT */
        bool                    sc_3wiremode;
 };
 
@@ -86,10 +96,26 @@
        return spi_compatible_match(sa, match, compat_data);
 }
 
+#ifdef FDT
+static void
+ssdfb_spi_dc_gpio_fdt(struct ssdfb_spi_softc *sc)
+{
+       devhandle_t devhandle = device_handle(sc->sc.sc_dev);
+       int phandle = devhandle_to_of(devhandle);
+
+       sc->sc_dc_gpio = fdtbus_gpio_acquire(phandle, "dc-gpios",
+           GPIO_PIN_OUTPUT);
+       if (sc->sc_dc_gpio != NULL) {
+               sc->sc_3wiremode = false;
+       }
+}
+#endif /* FDT */
+
 static void
 ssdfb_spi_attach(device_t parent, device_t self, void *aux)
 {
        struct ssdfb_spi_softc *sc = device_private(self);
+       devhandle_t devhandle = device_handle(self);
        struct cfdata *cf = device_cfdata(self);
        struct spi_attach_args *sa = aux;
        int flags = cf->cf_flags;
@@ -98,6 +124,8 @@
        sc->sc.sc_dev = self;
        sc->sc_sh = sa->sa_handle;
        sc->sc.sc_cookie = (void *)sc;
+
+       /* XXX Should get this from the device tree. */
        if ((flags & SSDFB_ATTACH_FLAG_PRODUCT_MASK) == SSDFB_PRODUCT_UNKNOWN)
                flags |= SSDFB_PRODUCT_SSD1322_GENERIC;
 
@@ -118,11 +146,21 @@
         * the bit that determines if the lower 8 bits are command or data.
         *
         * 4 wire mode sends 8 bit sequences and requires an auxiliary GPIO
-        * pin for the command/data bit. But in other to allocate a GPIO pin
-        * we need to use fdt, so only support 3 wire mode in this frontend,
-        * at least for now.
+        * pin for the command/data bit.
+        *
+        * Default to 3 wire mode.  If the device tree specifies a
+        * D/C GPIO pin, then we will use 4 wire mode.
         */
        sc->sc_3wiremode = true;
+       switch (devhandle_type(devhandle)) {
+#ifdef FDT
+       case DEVHANDLE_TYPE_OF:
+               ssdfb_spi_dc_gpio_fdt(sc);
+               break;
+#endif /* FDT */
+       default:
+               break;
+       }
 
        switch (flags & SSDFB_ATTACH_FLAG_PRODUCT_MASK) {
        case SSDFB_PRODUCT_SSD1322_GENERIC:
@@ -265,8 +303,15 @@
 static void
 ssdfb_spi_4wire_set_dc(struct ssdfb_spi_softc *sc, int value)
 {
+       /* TODO: refactor this if we ever support more that just FDT. */
+
+#ifdef FDT
+       KASSERT(sc->sc_dc_gpio != NULL);
+       fdtbus_gpio_write(sc->sc_dc_gpio, value);
+#else
        /* TODO: this should toggle an auxilliary GPIO pin */
        panic("ssdfb_spi_4wire_set_dc");
+#endif /* FDT */
 }
 
 static int