Module Name: src
Committed By: thorpej
Date: Sun Dec 22 23:50:43 UTC 2019
Modified Files:
src/sys/arch/arm/samsung: exynos_i2c.c
Log Message:
Use a separate lock (not the i2c bus lock) to synchronize with the
interrupt handler. Refactor the code slightly to make the lock use
consistent.
Also includes the changes for:
Cleanup i2c bus acquire / release, centralizing all of the logic into
iic_acquire_bus() / iic_release_bus(). "acquire" and "release" hooks
no longer need to be provided by back-end controller drivers (only if
they need special handling, e.g. powering on the i2c controller).
This results in the removal of a bunch of rendundant code from each
back-end controller driver.
Assert that we are not in hard interrupt context in iic_acquire_bus(),
iic_exec(), and iic_release_bus().
To generate a diff of this commit:
cvs rdiff -u -r1.17 -r1.18 src/sys/arch/arm/samsung/exynos_i2c.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/arm/samsung/exynos_i2c.c
diff -u src/sys/arch/arm/samsung/exynos_i2c.c:1.17 src/sys/arch/arm/samsung/exynos_i2c.c:1.18
--- src/sys/arch/arm/samsung/exynos_i2c.c:1.17 Fri Oct 18 06:13:38 2019
+++ src/sys/arch/arm/samsung/exynos_i2c.c Sun Dec 22 23:50:43 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: exynos_i2c.c,v 1.17 2019/10/18 06:13:38 skrll Exp $ */
+/* $NetBSD: exynos_i2c.c,v 1.18 2019/12/22 23:50:43 thorpej Exp $ */
/*
* Copyright (c) 2015 Jared D. McNeill <jmcne...@invisible.ca>
@@ -31,7 +31,7 @@
#include "opt_arm_debug.h"
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: exynos_i2c.c,v 1.17 2019/10/18 06:13:38 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: exynos_i2c.c,v 1.18 2019/12/22 23:50:43 thorpej Exp $");
#include <sys/param.h>
#include <sys/bus.h>
@@ -65,15 +65,12 @@ struct exynos_i2c_softc {
bool sc_sda_is_output;
struct i2c_controller sc_ic;
- kmutex_t sc_lock;
- kcondvar_t sc_cv;
+ kmutex_t sc_intr_lock;
+ kcondvar_t sc_intr_wait;
};
static int exynos_i2c_intr(void *);
-static int exynos_i2c_acquire_bus(void *, int);
-static void exynos_i2c_release_bus(void *, int);
-
static int exynos_i2c_send_start(void *, int);
static int exynos_i2c_send_stop(void *, int);
static int exynos_i2c_initiate_xfer(void *, i2c_addr_t, int);
@@ -155,8 +152,8 @@ exynos_i2c_attach(device_t parent, devic
return;
}
- mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_VM);
- cv_init(&sc->sc_cv, device_xname(self));
+ mutex_init(&sc->sc_intr_lock, MUTEX_DEFAULT, IPL_VM);
+ cv_init(&sc->sc_intr_wait, device_xname(self));
aprint_normal(" @ 0x%08x\n", (uint)addr);
if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) {
@@ -173,9 +170,8 @@ exynos_i2c_attach(device_t parent, devic
}
aprint_normal_dev(self, "interrupting on %s\n", intrstr);
+ iic_tag_init(&sc->sc_ic);
sc->sc_ic.ic_cookie = sc;
- sc->sc_ic.ic_acquire_bus = exynos_i2c_acquire_bus;
- sc->sc_ic.ic_release_bus = exynos_i2c_release_bus;
sc->sc_ic.ic_send_start = exynos_i2c_send_start;
sc->sc_ic.ic_send_stop = exynos_i2c_send_stop;
sc->sc_ic.ic_initiate_xfer = exynos_i2c_initiate_xfer;
@@ -206,31 +202,14 @@ exynos_i2c_intr(void *priv)
istatus &= ~IRQPEND;
I2C_WRITE(sc, IICCON, istatus);
- mutex_enter(&sc->sc_lock);
- cv_broadcast(&sc->sc_cv);
- mutex_exit(&sc->sc_lock);
+ mutex_enter(&sc->sc_intr_lock);
+ cv_broadcast(&sc->sc_intr_wait);
+ mutex_exit(&sc->sc_intr_lock);
return 1;
}
static int
-exynos_i2c_acquire_bus(void *cookie, int flags)
-{
- struct exynos_i2c_softc *i2c_sc = cookie;
-
- mutex_enter(&i2c_sc->sc_lock);
- return 0;
-}
-
-static void
-exynos_i2c_release_bus(void *cookie, int flags)
-{
- struct exynos_i2c_softc *i2c_sc = cookie;
-
- mutex_exit(&i2c_sc->sc_lock);
-}
-
-static int
exynos_i2c_wait(struct exynos_i2c_softc *sc, int flags)
{
int error, retry;
@@ -240,8 +219,9 @@ exynos_i2c_wait(struct exynos_i2c_softc
while (--retry > 0) {
if ((flags & I2C_F_POLL) == 0) {
- error = cv_timedwait_sig(&sc->sc_cv, &sc->sc_lock,
- uimax(mstohz(10), 1));
+ error = cv_timedwait_sig(&sc->sc_intr_wait,
+ &sc->sc_intr_lock,
+ uimax(mstohz(10), 1));
if (error) {
return error;
}
@@ -265,46 +245,90 @@ exynos_i2c_wait(struct exynos_i2c_softc
static int
-exynos_i2c_send_start(void *cookie, int flags)
+exynos_i2c_send_start_locked(struct exynos_i2c_softc *sc, int flags)
{
- struct exynos_i2c_softc *sc = cookie;
I2C_WRITE(sc, IICSTAT, 0xF0);
return 0;
}
static int
-exynos_i2c_send_stop(void *cookie, int flags)
+exynos_i2c_send_stop_locked(struct exynos_i2c_softc *sc, int flags)
{
- struct exynos_i2c_softc *sc = cookie;
I2C_WRITE(sc, IICSTAT, 0xD0);
return 0;
}
static int
+exynos_i2c_write_byte_locked(struct exynos_i2c_softc *sc, uint8_t byte,
+ int flags)
+{
+ int error = exynos_i2c_wait(sc, flags);
+ if (error) {
+ return error;
+ }
+ I2C_WRITE(sc, IICDS, byte);
+ return 0;
+}
+
+static int
+exynos_i2c_send_start(void *cookie, int flags)
+{
+ struct exynos_i2c_softc *sc = cookie;
+
+ mutex_enter(&sc->sc_intr_lock);
+ int error = exynos_i2c_send_start_locked(sc, flags);
+ mutex_exit(&sc->sc_intr_lock);
+ return error;
+}
+
+static int
+exynos_i2c_send_stop(void *cookie, int flags)
+{
+ struct exynos_i2c_softc *sc = cookie;
+
+ mutex_enter(&sc->sc_intr_lock);
+ int error = exynos_i2c_send_stop_locked(sc, flags);
+ mutex_exit(&sc->sc_intr_lock);
+ return error;
+}
+
+static int
exynos_i2c_initiate_xfer(void *cookie, i2c_addr_t addr, int flags)
{
struct exynos_i2c_softc *sc = cookie;
uint8_t byte = addr & 0x7f;
+ int error;
+
if (flags & I2C_F_READ)
byte |= READBIT;
else
byte &= ~READBIT;
+
+ mutex_enter(&sc->sc_intr_lock);
I2C_WRITE(sc, IICADD, addr);
- exynos_i2c_send_start(cookie, flags);
- exynos_i2c_write_byte(cookie, byte, flags);
- return exynos_i2c_wait(cookie, flags);
+ exynos_i2c_send_start_locked(sc, flags);
+ exynos_i2c_write_byte_locked(sc, byte, flags);
+ error = exynos_i2c_wait(cookie, flags);
+ mutex_exit(&sc->sc_intr_lock);
+
+ return error;
}
static int
exynos_i2c_read_byte(void *cookie, uint8_t *bytep, int flags)
{
struct exynos_i2c_softc *sc = cookie;
+
+ mutex_enter(&sc->sc_intr_lock);
int error = exynos_i2c_wait(sc, flags);
- if (error)
+ if (error) {
+ mutex_exit(&sc->sc_intr_lock);
return error;
+ }
*bytep = I2C_READ(sc, IICDS) & 0xff;
if (flags & I2C_F_STOP)
- exynos_i2c_send_stop(cookie, flags);
+ exynos_i2c_send_stop_locked(sc, flags);
+ mutex_exit(&sc->sc_intr_lock);
return 0;
}
@@ -312,9 +336,9 @@ static int
exynos_i2c_write_byte(void *cookie, uint8_t byte, int flags)
{
struct exynos_i2c_softc *sc = cookie;
- int error = exynos_i2c_wait(sc, flags);
- if (error)
- return error;
- I2C_WRITE(sc, IICDS, byte);
- return 0;
+
+ mutex_enter(&sc->sc_intr_lock);
+ int error = exynos_i2c_write_byte_locked(sc, byte, flags);
+ mutex_exit(&sc->sc_intr_lock);
+ return error;
}
