[src/trunk]: src/sys/dev/i2c Allow drivers to provide their own read/write re...

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

details:   https://anonhg.NetBSD.org/src/rev/166a250d7933
branches:  trunk
changeset: 827470:166a250d7933
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Sun Oct 29 14:59:05 2017 +0000

description:
Allow drivers to provide their own read/write register functions. While
here, sprinkle KASSERTs to verify that the i2c lock is held where it
should be.

diffstat:

 sys/dev/i2c/gttwsi_core.c |  35 +++++++++++++++++++++++++++++++----
 sys/dev/i2c/gttwsivar.h   |   5 ++++-
 2 files changed, 35 insertions(+), 5 deletions(-)

diffs (139 lines):

diff -r 8fa390414412 -r 166a250d7933 sys/dev/i2c/gttwsi_core.c
--- a/sys/dev/i2c/gttwsi_core.c Sun Oct 29 14:07:11 2017 +0000
+++ b/sys/dev/i2c/gttwsi_core.c Sun Oct 29 14:59:05 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: gttwsi_core.c,v 1.2 2014/11/23 13:37:27 jmcneill Exp $ */
+/*     $NetBSD: gttwsi_core.c,v 1.3 2017/10/29 14:59:05 jmcneill Exp $ */
 /*
  * Copyright (c) 2008 Eiji Kawauchi.
  * All rights reserved.
@@ -66,7 +66,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: gttwsi_core.c,v 1.2 2014/11/23 13:37:27 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: gttwsi_core.c,v 1.3 2017/10/29 14:59:05 jmcneill Exp $");
 #include "locators.h"
 
 #include <sys/param.h>
@@ -94,7 +94,7 @@
 static int     gttwsi_wait(struct gttwsi_softc *, uint32_t, uint32_t, int);
 
 static inline uint32_t
-gttwsi_read_4(struct gttwsi_softc *sc, uint32_t reg)
+gttwsi_default_read_4(struct gttwsi_softc *sc, uint32_t reg)
 {
        uint32_t val = bus_space_read_4(sc->sc_bust, sc->sc_bush, reg);
 #ifdef TWSI_DEBUG
@@ -106,7 +106,7 @@
 }
 
 static inline void
-gttwsi_write_4(struct gttwsi_softc *sc, uint32_t reg, uint32_t val)
+gttwsi_default_write_4(struct gttwsi_softc *sc, uint32_t reg, uint32_t val)
 {
        bus_space_write_4(sc->sc_bust, sc->sc_bush, reg, val);
 #ifdef TWSI_DEBUG
@@ -117,7 +117,17 @@
        return;
 }
 
+static inline uint32_t
+gttwsi_read_4(struct gttwsi_softc *sc, uint32_t reg)
+{
+       return sc->sc_reg_read(sc, reg);
+}
 
+static inline void
+gttwsi_write_4(struct gttwsi_softc *sc, uint32_t reg, uint32_t val)
+{
+       return sc->sc_reg_write(sc, reg, val);
+}
 
 /* ARGSUSED */
 void
@@ -133,6 +143,11 @@
        sc->sc_bust = iot;
        sc->sc_bush = ioh;
 
+       if (sc->sc_reg_read == NULL)
+               sc->sc_reg_read = gttwsi_default_read_4;
+       if (sc->sc_reg_write == NULL)
+               sc->sc_reg_write = gttwsi_default_write_4;
+
        mutex_init(&sc->sc_buslock, MUTEX_DEFAULT, IPL_NONE);
        mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_BIO);
        cv_init(&sc->sc_cv, device_xname(self));
@@ -213,6 +228,8 @@
        struct gttwsi_softc *sc = v;
        int expect;
 
+       KASSERT(mutex_owned(&sc->sc_buslock));
+
        if (sc->sc_started)
                expect = STAT_RSCT;
        else
@@ -228,6 +245,8 @@
        int retry = TWSI_RETRY_COUNT;
        uint32_t control;
 
+       KASSERT(mutex_owned(&sc->sc_buslock));
+
        sc->sc_started = false;
 
        /* Interrupt is not generated for STAT_NRS. */
@@ -253,6 +272,8 @@
        uint32_t data, expect;
        int error, read;
 
+       KASSERT(mutex_owned(&sc->sc_buslock));
+
        gttwsi_send_start(v, flags);
 
        read = (flags & I2C_F_READ) != 0;
@@ -297,6 +318,8 @@
        struct gttwsi_softc *sc = v;
        int error;
 
+       KASSERT(mutex_owned(&sc->sc_buslock));
+
        if (flags & I2C_F_LAST)
                error = gttwsi_wait(sc, 0, STAT_MRRD_ANT, flags);
        else
@@ -314,6 +337,8 @@
        struct gttwsi_softc *sc = v;
        int error;
 
+       KASSERT(mutex_owned(&sc->sc_buslock));
+
        gttwsi_write_4(sc, TWSI_DATA, val);
        error = gttwsi_wait(sc, 0, STAT_MTDB_AR, flags);
        if (flags & I2C_F_STOP)
@@ -328,6 +353,8 @@
        uint32_t status;
        int timo, error = 0;
 
+       KASSERT(mutex_owned(&sc->sc_buslock));
+
        DELAY(5);
        if (!(flags & I2C_F_POLL))
                control |= CONTROL_INTEN;
diff -r 8fa390414412 -r 166a250d7933 sys/dev/i2c/gttwsivar.h
--- a/sys/dev/i2c/gttwsivar.h   Sun Oct 29 14:07:11 2017 +0000
+++ b/sys/dev/i2c/gttwsivar.h   Sun Oct 29 14:59:05 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: gttwsivar.h,v 1.2 2014/11/23 13:37:27 jmcneill Exp $   */
+/*     $NetBSD: gttwsivar.h,v 1.3 2017/10/29 14:59:05 jmcneill Exp $   */
 /*
  * Copyright (c) 2008 Eiji Kawauchi.
  * All rights reserved.
@@ -89,6 +89,9 @@
        kcondvar_t sc_cv;
 
        bool sc_iflg_rwc;
+
+       uint32_t (*sc_reg_read)(struct gttwsi_softc *, uint32_t);
+       void (*sc_reg_write)(struct gttwsi_softc *, uint32_t, uint32_t);
 };
 
 void   gttwsi_attach_subr(device_t, bus_space_tag_t, bus_space_handle_t);