ahci at fdt where the firmware doesnt help

[David Gwynne]

the banana pi r2 pro has a usable sata port, but ahci wasnt finding
anything attached to it.

the fdt glue looked like it assumed the boot loader did a lot of
work to get things going. however, i havent figured out how to
configure u-boot to do ahci, and quartz_uefi doesn't have ahci/sata
working yet. the boot loaders arent quite there yet, so i tried to
make the driver better.

the obvious tweak was to enable clocks and the phy, but that wasnt
enough to get it working.

jared mcneill showed me the code he's been trying to get ahci working in
quartz_uefi with, and it showed setting the ports implemented register.

the sata nodes in the rk356x device tree populates a ports-implemented
property, which the yaml doco says can be provided if the platform/
firmware doesnt init the register itself. i tried using that value
instead of a PI read, and that didnt work. having the fdt glue set
the register (like jmcneill does) before calling the bus independent
code does work though.

so i see this now:

ahci0 at mainbus0: AHCI 1.3
ahci0: port 0: 3.0Gb/s
scsibus0 at ahci0: 32 targets
sd0 at scsibus0 targ 0 lun 0: <ATA, MZ-5EA1000-0D3, AXM1> naa.5002538250006f47
sd0: 95396MB, 512 bytes/sector, 195371568 sectors, thin

ok?

Index: ahci_fdt.c
===================================================================
RCS file: /cvs/src/sys/dev/fdt/ahci_fdt.c,v
retrieving revision 1.7
diff -u -p -r1.7 ahci_fdt.c
--- ahci_fdt.c  25 May 2022 03:03:58 -0000      1.7
+++ ahci_fdt.c  6 Apr 2023 21:30:31 -0000
@@ -30,6 +30,8 @@
 #include <dev/ic/ahcivar.h>
 
 #include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_clock.h>
+#include <dev/ofw/ofw_misc.h>
 #include <dev/ofw/fdt.h>
 
 int    ahci_fdt_match(struct device *, void *, void *);
@@ -63,6 +65,7 @@ ahci_fdt_attach(struct device *parent, s
 {
        struct ahci_softc *sc = (struct ahci_softc *) self;
        struct fdt_attach_args *faa = aux;
+       uint32_t pi;
 
        if (faa->fa_nreg < 1)
                return;
@@ -82,11 +85,19 @@ ahci_fdt_attach(struct device *parent, s
                goto unmap;
        }
 
+       clock_set_assigned(faa->fa_node);
+       clock_enable_all(faa->fa_node);
+       phy_enable(faa->fa_node, "sata-phy");
+
+       pi = OF_getpropint(faa->fa_node, "ports-implemented", 0x0);
+       if (pi != 0)
+               bus_space_write_4(sc->sc_iot, sc->sc_ioh, AHCI_REG_PI, pi);
+
        printf(":");
 
        if (ahci_attach(sc) != 0) {
                /* error printed by ahci_attach */
-               goto irq;
+               goto irq; /* disable phy and clocks? */
        }
 
        return;