Hi,
This enables fifo support in pluart(4). While here, I changed the
attachment output to look more like com(4). Tested on my rpi3b which has
a 16 byte fifo.

Comments? OK?

diff --git sys/dev/ic/pluart.c sys/dev/ic/pluart.c
index eaa11b6c44b..601435c0e0c 100644
--- sys/dev/ic/pluart.c
+++ sys/dev/ic/pluart.c
@@ -99,6 +99,13 @@
 #define UART_CR_CTSE           (1 << 14)       /* CTS hardware flow control 
enable */
 #define UART_CR_RTSE           (1 << 15)       /* RTS hardware flow control 
enable */
 #define UART_IFLS              0x34            /* Interrupt FIFO level select 
register */
+#define UART_IFLS_RX_SHIFT     3               /* RX level in bits [5:3] */
+#define UART_IFLS_TX_SHIFT     0               /* TX level in bits [2:0] */
+#define UART_IFLS_1_8          0               /* FIFO 1/8 full */
+#define UART_IFLS_1_4          1               /* FIFO 1/4 full */
+#define UART_IFLS_1_2          2               /* FIFO 1/2 full */
+#define UART_IFLS_3_4          3               /* FIFO 3/4 full */
+#define UART_IFLS_7_8          4               /* FIFO 7/8 full */
 #define UART_IMSC              0x38            /* Interrupt mask set/clear 
register */
 #define UART_IMSC_RIMIM                (1 << 0)
 #define UART_IMSC_CTSMIM       (1 << 1)
@@ -115,6 +122,11 @@
 #define UART_MIS               0x40            /* Masked interrupt status 
register */
 #define UART_ICR               0x44            /* Interrupt clear register */
 #define UART_DMACR             0x48            /* DMA control register */
+#define UART_PID0              0xfe0           /* Peripheral identification 
register 0 */
+#define UART_PID1              0xfe4           /* Peripheral identification 
register 1 */
+#define UART_PID2              0xfe8           /* Peripheral identification 
register 2 */
+#define UART_PID2_REV(x)       ((x) >> 4)
+#define UART_PID3              0xfec           /* Peripheral identification 
register 3 */
 #define UART_SPACE             0x100
 
 void pluartcnprobe(struct consdev *cp);
@@ -150,7 +162,12 @@ struct cdevsw pluartdev =
 void
 pluart_attach_common(struct pluart_softc *sc, int console)
 {
-       int maj;
+       int maj, rev;
+
+       rev = UART_PID2_REV(bus_space_read_4(sc->sc_iot, sc->sc_ioh,
+           UART_PID2));
+
+       printf(": rev %d, %d byte fifo\n", rev, rev < 3 ? 16 : 32);
 
        if (console) {
                /* Locate the major number. */
@@ -159,7 +176,7 @@ pluart_attach_common(struct pluart_softc *sc, int console)
                                break;
                cn_tab->cn_dev = makedev(maj, sc->sc_dev.dv_unit);
 
-               printf(": console");
+               printf("%s: console\n", sc->sc_dev.dv_xname);
                SET(sc->sc_hwflags, COM_HW_CONSOLE);
        }
 
@@ -171,13 +188,26 @@ pluart_attach_common(struct pluart_softc *sc, int console)
                panic("%s: can't establish soft interrupt.",
                    sc->sc_dev.dv_xname);
 
-       bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_IMSC, (UART_IMSC_RXIM | 
UART_IMSC_TXIM));
+       /*
+        * The transmit FIFO size is set to 3/4 of the actual size as interrupts
+        * can only be triggered when the FIFO is partially full. Once
+        * triggered, we know that at least this amount is available in the
+        * FIFO.
+        */
+       if (rev < 3)
+               sc->sc_fifolen = 24;
+       else
+               sc->sc_fifolen = 12;
+       bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_IFLS,
+           (UART_IFLS_3_4 << UART_IFLS_RX_SHIFT) |
+           (UART_IFLS_1_4 << UART_IFLS_TX_SHIFT));
+       sc->sc_imsc = UART_IMSC_RXIM | UART_IMSC_RTIM | UART_IMSC_TXIM;
+       bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_IMSC, sc->sc_imsc);
        bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_ICR, 0x7ff);
+       /* Enable FIFO. */
        bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_LCR_H,
-           bus_space_read_4(sc->sc_iot, sc->sc_ioh, UART_LCR_H) &
-           ~UART_LCR_H_FEN);
-
-       printf("\n");
+           bus_space_read_4(sc->sc_iot, sc->sc_ioh, UART_LCR_H) |
+           UART_LCR_H_FEN);
 }
 
 int
@@ -197,19 +227,26 @@ pluart_intr(void *arg)
        if (sc->sc_tty == NULL)
                return 0;
 
-       if (!ISSET(is, UART_IMSC_RXIM) && !ISSET(is, UART_IMSC_TXIM))
+       if (!ISSET(is, UART_IMSC_RXIM) && !ISSET(is, UART_IMSC_RTIM) &&
+           !ISSET(is, UART_IMSC_TXIM))
                return 0;
 
-       if (ISSET(is, UART_IMSC_TXIM) && ISSET(tp->t_state, TS_BUSY)) {
-               CLR(tp->t_state, TS_BUSY | TS_FLUSH);
-               if (sc->sc_halt > 0)
-                       wakeup(&tp->t_outq);
-               (*linesw[tp->t_line].l_start)(tp);
+       if (ISSET(is, UART_IMSC_TXIM)) {
+               /* Disable transmit interrupt. */
+               bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_IMSC,
+                   sc->sc_imsc & ~UART_IMSC_TXIM);
+
+               if (ISSET(tp->t_state, TS_BUSY)) {
+                       CLR(tp->t_state, TS_BUSY | TS_FLUSH);
+                       if (sc->sc_halt > 0)
+                               wakeup(&tp->t_outq);
+                       (*linesw[tp->t_line].l_start)(tp);
+               }
        }
 
        p = sc->sc_ibufp;
 
-       while (ISSET(bus_space_read_4(iot, ioh, UART_FR), UART_FR_RXFF)) {
+       while (!ISSET(bus_space_read_4(iot, ioh, UART_FR), UART_FR_RXFE)) {
                c = bus_space_read_2(iot, ioh, UART_DR);
                if (c & UART_DR_BE) {
 #ifdef DDB
@@ -322,11 +359,11 @@ pluart_param(struct tty *tp, struct termios *t)
 void
 pluart_start(struct tty *tp)
 {
+       char buf[32];   /* fifo max size */
        struct pluart_softc *sc = pluart_cd.cd_devs[DEVUNIT(tp->t_dev)];
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
-       u_int16_t fr;
-       int s;
+       int i, n, s;
 
        s = spltty();
        if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
@@ -336,11 +373,13 @@ pluart_start(struct tty *tp)
                goto out;
        SET(tp->t_state, TS_BUSY);
 
-       fr = bus_space_read_4(iot, ioh, UART_FR);
-       while (tp->t_outq.c_cc != 0 && ISSET(fr, UART_FR_TXFE)) {
-               bus_space_write_4(iot, ioh, UART_DR, getc(&tp->t_outq));
-               fr = bus_space_read_4(iot, ioh, UART_FR);
-       }
+       /* Enable transmit interrupt. */
+       bus_space_write_4(sc->sc_iot, sc->sc_ioh, UART_IMSC, sc->sc_imsc);
+
+       n = q_to_b(&tp->t_outq, buf, sc->sc_fifolen);
+       for (i = 0; i < n; i++)
+               bus_space_write_4(iot, ioh, UART_DR, buf[i]);
+
 out:
        splx(s);
 }
diff --git sys/dev/ic/pluartvar.h sys/dev/ic/pluartvar.h
index 8fcbed14d5c..5181723a066 100644
--- sys/dev/ic/pluartvar.h
+++ sys/dev/ic/pluartvar.h
@@ -45,6 +45,7 @@ struct pluart_softc {
 #define COM_SW_MDMBUF   0x08
 #define COM_SW_PPS      0x10
        int             sc_fifolen;
+       int             sc_imsc;
 
        u_int8_t        sc_initialize;
        u_int8_t        sc_cua;

Reply via email to