Add a pwm subsystem so we can configure pwm controller from kernel and userland.

The pwm subsystem consist of API for PWM controllers, pwmbus to register them
and a pwm(8) utility to talk to them from userland.

Reviewed by:	oshgobo (capsicum), bcr (manpage), 0mp (manpage)
Differential Revision:	https://reviews.freebsd.org/D17938

1 files changed, 64 insertions, 0 deletions

diff --git a/sys/dev/pwm/pwmbus.h b/sys/dev/pwm/pwmbus.h
new file mode 100644
index 000000000000..077c7d0f3d59
--- /dev/null
+++ b/sys/dev/pwm/pwmbus.h
@@ -0,0 +1,64 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2018 Emmanuel Vadot <manu@FreeBSD.org>
+ * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _PWMBUS_H_
+
+#include <dev/ofw/openfirm.h>
+#include <sys/pwm.h>
+
+struct pwm_channel {
+	device_t	dev;
+	device_t	busdev;
+	int		channel;
+	uint64_t	period;
+	uint64_t	duty;
+	uint32_t	flags;
+	bool		enabled;
+};
+typedef struct pwm_channel *pwm_channel_t;
+
+device_t pwmbus_attach_bus(device_t dev);
+int pwmbus_acquire_channel(device_t bus, int channel);
+int pwmbus_release_channel(device_t bus, int channel);
+
+int
+pwm_get_by_ofw_propidx(device_t consumer, phandle_t node,
+    const char *prop_name, int idx, pwm_channel_t *channel);
+int
+pwm_get_by_ofw_idx(device_t consumer, phandle_t node, int idx,
+    pwm_channel_t *out_channel);
+int
+pwm_get_by_ofw_property(device_t consumer, phandle_t node,
+    const char *prop_name, pwm_channel_t *out_channel);
+int
+pwm_get_by_ofw_name(device_t consumer, phandle_t node, const char *name,
+    pwm_channel_t *out_channel);
+
+#endif /* _PWMBUS_H_ */