[src/trunk]: src/sys/dev/fdt Add basic pwm-fan driver. This doesn't have any ...

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

details:   https://anonhg.NetBSD.org/src/rev/a48d7c3a6112
branches:  trunk
changeset: 320412:a48d7c3a6112
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Wed Jul 04 23:08:06 2018 +0000

description:
Add basic pwm-fan driver. This doesn't have any smarts yet other than
turning the fan on at 100% duty cycle.

diffstat:

 sys/dev/fdt/files.fdt |    6 +-
 sys/dev/fdt/pwm_fan.c |  128 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 133 insertions(+), 1 deletions(-)

diffs (152 lines):

diff -r cbee7356c573 -r a48d7c3a6112 sys/dev/fdt/files.fdt
--- a/sys/dev/fdt/files.fdt     Wed Jul 04 23:06:54 2018 +0000
+++ b/sys/dev/fdt/files.fdt     Wed Jul 04 23:08:06 2018 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: files.fdt,v 1.35 2018/06/30 16:22:56 jmcneill Exp $
+# $NetBSD: files.fdt,v 1.36 2018/07/04 23:08:06 jmcneill Exp $
 
 include        "external/bsd/libfdt/conf/files.libfdt"
 
@@ -78,6 +78,10 @@
 attach pwmbacklight at fdt
 file   dev/fdt/pwm_backlight.c                 pwmbacklight
 
+device pwmfan
+attach pwmfan at fdt
+file   dev/fdt/pwm_fan.c                       pwmfan
+
 device ausoc: audiobus
 attach ausoc at fdt
 file   dev/fdt/ausoc.c                         ausoc
diff -r cbee7356c573 -r a48d7c3a6112 sys/dev/fdt/pwm_fan.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/dev/fdt/pwm_fan.c     Wed Jul 04 23:08:06 2018 +0000
@@ -0,0 +1,128 @@
+/* $NetBSD: pwm_fan.c,v 1.1 2018/07/04 23:08:06 jmcneill Exp $ */
+
+/*-
+ * Copyright (c) 2018 Jared McNeill <jmcneill%invisible.ca@localhost>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__KERNEL_RCSID(0, "$NetBSD: pwm_fan.c,v 1.1 2018/07/04 23:08:06 jmcneill Exp $");
+
+#include <sys/param.h>
+#include <sys/bus.h>
+#include <sys/device.h>
+#include <sys/systm.h>
+#include <sys/sysctl.h>
+#include <sys/kmem.h>
+#include <sys/gpio.h>
+
+#include <dev/pwm/pwmvar.h>
+
+#include <dev/fdt/fdtvar.h>
+
+struct pwm_fan_softc {
+       device_t                sc_dev;
+       pwm_tag_t               sc_pwm;
+       struct fdtbus_gpio_pin *sc_pin;
+
+       u_int                   *sc_levels;
+       u_int                   sc_nlevels;
+};
+
+static int     pwm_fan_match(device_t, cfdata_t, void *);
+static void    pwm_fan_attach(device_t, device_t, void *);
+
+static void    pwm_fan_set(struct pwm_fan_softc *, u_int);
+
+static const char *compatible[] = {
+       "pwm-fan",
+       NULL
+};
+
+CFATTACH_DECL_NEW(pwmfan, sizeof(struct pwm_fan_softc),
+       pwm_fan_match, pwm_fan_attach, NULL, NULL);
+
+static int
+pwm_fan_match(device_t parent, cfdata_t cf, void *aux)
+{
+       struct fdt_attach_args * const faa = aux;
+
+       return of_match_compatible(faa->faa_phandle, compatible);
+}
+
+static void
+pwm_fan_attach(device_t parent, device_t self, void *aux)
+{
+       struct pwm_fan_softc * const sc = device_private(self);
+       struct fdt_attach_args * const faa = aux;
+       const int phandle = faa->faa_phandle;
+       const u_int *levels;
+       u_int n;
+       int len;
+
+       sc->sc_dev = self;
+       sc->sc_pwm = fdtbus_pwm_acquire(phandle, "pwms");
+       if (sc->sc_pwm == NULL) {
+               aprint_error(": couldn't acquire pwm\n");
+               return;
+       }
+
+       levels = fdtbus_get_prop(phandle, "cooling-levels", &len);
+       if (len < 4) {
+               aprint_error(": couldn't get 'cooling-levels' property\n");
+               return;
+       }
+       sc->sc_levels = kmem_alloc(len, KM_SLEEP);
+       sc->sc_nlevels = len / 4;
+       for (n = 0; n < sc->sc_nlevels; n++)
+               sc->sc_levels[n] = be32toh(levels[n]);
+
+       aprint_naive("\n");
+       aprint_normal(": PWM Fan");
+       aprint_normal(" (levels");
+       for (n = 0; n < sc->sc_nlevels; n++) {
+               aprint_normal(" %u%%", (sc->sc_levels[n] * 100) / 255);
+       }
+       aprint_normal(")\n");
+
+       /* Select the highest cooling level */
+       pwm_fan_set(sc, 255);
+}
+
+static void
+pwm_fan_set(struct pwm_fan_softc *sc, u_int level)
+{
+       struct pwm_config conf;
+
+       if (level > 255)
+               level = 255;
+
+       aprint_debug_dev(sc->sc_dev, "set duty cycle to %u%%\n", (level * 100) / 255);
+
+       pwm_disable(sc->sc_pwm);
+       pwm_get_config(sc->sc_pwm, &conf);
+       conf.duty_cycle = (conf.period * level) / 255;
+       pwm_set_config(sc->sc_pwm, &conf);
+       pwm_enable(sc->sc_pwm);
+}