Partially catch up with device tree bindings in mainline Linux.

Initialize the burst size register such that DMA channels that haven't
been initialized by Apple's bootloader also work.

ok patrick@

diff --git a/sys/arch/arm64/dev/apldma.c b/sys/arch/arm64/dev/apldma.c
index a9a21d4..814d055 100644 (file)
--- a/sys/arch/arm64/dev/apldma.c
+++ b/sys/arch/arm64/dev/apldma.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: apldma.c,v 1.1 2022/02/02 22:55:57 kettenis Exp $     */
+/*     $OpenBSD: apldma.c,v 1.2 2022/07/27 20:18:46 kettenis Exp $     */
 /*
  * Copyright (c) 2022 Mark Kettenis <kettenis@openbsd.org>
  *
@@ -38,36 +38,43 @@
  * dropped as soon as official bindings are available.
  */
 
+/*
+ * The device tree bindings for this hardware use separate Tx and Rx
+ * channels with Tx channels using even channel numbers and Rx
+ * channels using odd channel numbers.
+ */
+
 #define DMA_TX_EN                      0x0000
 #define DMA_TX_EN_CLR                  0x0004
 #define DMA_TX_INTR                    0x0034
 
-#define DMA_TX_CTL(chan)               (0x8000 + (chan) * 0x400)
+#define DMA_TX_CTL(chan)               (0x8000 + ((chan) / 2) * 0x400)
 #define  DMA_TX_CTL_RESET_RINGS                (1 << 0)
-#define DMA_TX_INTRSTAT(chan)          (0x8014 + (chan) * 0x400)
+#define DMA_TX_INTRSTAT(chan)          (0x8014 + ((chan) / 2) * 0x400)
 #define  DMA_TX_INTRSTAT_DESC_DONE     (1 << 0)
 #define  DMA_TX_INTRSTAT_ERR           (1 << 6)
-#define DMA_TX_INTRMASK(chan)          (0x8024 + (chan) * 0x400)
+#define DMA_TX_INTRMASK(chan)          (0x8024 + ((chan) / 2) * 0x400)
 #define  DMA_TX_INTRMASK_DESC_DONE     (1 << 0)
 #define  DMA_TX_INTRMASK_ERR           (1 << 6)
-#define DMA_TX_BUS_WIDTH(chan)         (0x8040 + (chan) * 0x400)
+#define DMA_TX_BUS_WIDTH(chan)         (0x8040 + ((chan) / 2) * 0x400)
 #define  DMA_TX_BUS_WIDTH_8BIT         (0 << 0)
 #define  DMA_TX_BUS_WIDTH_16BIT                (1 << 0)
 #define  DMA_TX_BUS_WIDTH_32BIT                (2 << 0)
 #define  DMA_TX_BUS_WIDTH_FRAME_2_WORDS        (1 << 4)
 #define  DMA_TX_BUS_WIDTH_FRAME_4_WORDS        (2 << 4)
-#define DMA_TX_BURST_SIZE(chan)                (0x8054 + (chan) * 0x400)
-#define DMA_TX_RESIDUE(chan)           (0x8064 + (chan) * 0x400)
-#define DMA_TX_DESC_RING(chan)         (0x8070 + (chan) * 0x400)
+#define DMA_TX_BURST_SIZE(chan)                (0x8054 + ((chan) / 2) * 0x400)
+#define  DMA_TX_BURST_SIZE_MAGIC       0x00c00060
+#define DMA_TX_RESIDUE(chan)           (0x8064 + ((chan) / 2) * 0x400)
+#define DMA_TX_DESC_RING(chan)         (0x8070 + ((chan) / 2) * 0x400)
 #define  DMA_TX_DESC_RING_FULL         (1 << 9)
-#define DMA_TX_REPORT_RING(chan)       (0x8074 + (chan) * 0x400)
+#define DMA_TX_REPORT_RING(chan)       (0x8074 + ((chan) / 2) * 0x400)
 #define  DMA_TX_REPORT_RING_EMPTY      (1 << 8)
-#define DMA_TX_DESC_WRITE(chan)                (0x10000 + (chan) * 4)
-#define DMA_TX_REPORT_READ(chan)       (0x10100 + (chan) * 4)
+#define DMA_TX_DESC_WRITE(chan)                (0x10000 + ((chan) / 2) * 4)
+#define DMA_TX_REPORT_READ(chan)       (0x10100 + ((chan) / 2) * 4)
 
 #define DMA_DESC_NOTIFY                        (1 << 16)
 #define DMA_NUM_DESCRIPTORS            4
-#define DMA_NUM_CHANNELS               4
+#define DMA_NUM_INTERRUPTS             4
 
 #define HREAD4(sc, reg)                                                        \
        (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg)))
@@ -101,7 +108,8 @@ struct apldma_softc {
        int                     sc_node;
        void                    *sc_ih;
 
-       struct apldma_channel   *sc_ac[DMA_NUM_CHANNELS];
+       int                     sc_nchannels;
+       struct apldma_channel   **sc_ac;
 };
 
 struct apldma_softc *apldma_sc;
@@ -145,6 +153,14 @@ apldma_attach(struct device *parent, struct device *self, void *aux)
                return;
        }
 
+       sc->sc_nchannels = OF_getpropint(faa->fa_node, "dma-channels", 0);
+       if (sc->sc_nchannels == 0) {
+               printf(": no DMA channels\n");
+               goto unmap;
+       }
+       sc->sc_ac = mallocarray(sc->sc_nchannels,
+           sizeof(struct apldma_channel), M_DEVBUF, M_WAITOK | M_ZERO);
+
        sc->sc_dmat = faa->fa_dmat;
        sc->sc_node = faa->fa_node;
 
@@ -154,7 +170,7 @@ apldma_attach(struct device *parent, struct device *self, void *aux)
            apldma_intr, sc, sc->sc_dev.dv_xname);
        if (sc->sc_ih == NULL) {
                printf(": can't establish interrupt\n");
-               goto unmap;
+               goto free;
        }
 
        printf("\n");
@@ -162,6 +178,9 @@ apldma_attach(struct device *parent, struct device *self, void *aux)
        apldma_sc = sc;
        return;
 
+free:
+       free(sc->sc_ac, M_DEVBUF,
+           sc->sc_nchannels * sizeof(struct apldma_channel));
 unmap:
        bus_space_unmap(sc->sc_iot, sc->sc_ioh, faa->fa_reg[0].size);
 }
@@ -199,8 +218,8 @@ apldma_intr(void *arg)
        unsigned int chan, i;
 
        intr = HREAD4(sc, DMA_TX_INTR);
-       for (chan = 0; chan < DMA_NUM_CHANNELS; chan++) {
-               if ((intr & (1 << chan)) == 0)
+       for (chan = 0; chan < sc->sc_nchannels; chan += 2) {
+               if ((intr & (1 << (chan / 2))) == 0)
                        continue;
 
                intrstat = HREAD4(sc, DMA_TX_INTRSTAT(chan));
@@ -208,7 +227,7 @@ apldma_intr(void *arg)
 
                if ((intrstat & DMA_TX_INTRSTAT_DESC_DONE) == 0)
                        continue;
-               
+
                for (i = 0; i < DMA_NUM_DESCRIPTORS; i++) {
                        uint32_t status;
 
@@ -240,7 +259,11 @@ apldma_alloc_channel(unsigned int chan)
        struct apldma_softc *sc = apldma_sc;
        struct apldma_channel *ac;
 
-       if (chan >= DMA_NUM_CHANNELS)
+       if (chan >= sc->sc_nchannels)
+               return NULL;
+
+       /* We only support Tx channels for now. */
+       if ((chan % 2) != 0)
                return NULL;
 
        ac = malloc(sizeof(*ac), M_DEVBUF, M_WAITOK);
@@ -337,6 +360,7 @@ apldma_trigger_output(struct apldma_channel *ac, void *start, void *end,
        default:
                return EINVAL;
        }
+       HWRITE4(sc, DMA_TX_BURST_SIZE(ac->ac_chan), DMA_TX_BURST_SIZE_MAGIC);
 
        /* Reset rings. */
        HWRITE4(sc, DMA_TX_CTL(ac->ac_chan), DMA_TX_CTL_RESET_RINGS);
@@ -351,7 +375,7 @@ apldma_trigger_output(struct apldma_channel *ac, void *start, void *end,
        apldma_fill_descriptors(ac);
 
        /* Start DMA transfer. */
-       HWRITE4(sc, DMA_TX_EN, 1 << ac->ac_chan);
+       HWRITE4(sc, DMA_TX_EN, 1 << (ac->ac_chan / 2));
 
        return 0;
 }
@@ -362,7 +386,7 @@ apldma_halt_output(struct apldma_channel *ac)
        struct apldma_softc *sc = ac->ac_sc;
 
        /* Stop DMA transfer. */
-       HWRITE4(sc, DMA_TX_EN_CLR, 1 << ac->ac_chan);
+       HWRITE4(sc, DMA_TX_EN_CLR, 1 << (ac->ac_chan / 2));
 
        /* Mask all interrupts. */
        HWRITE4(sc, DMA_TX_INTRMASK(ac->ac_chan), 0);