[src/trunk]: src/sys/dev/fdt Add support for simple fixed-rate clock source b...

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

details:   https://anonhg.NetBSD.org/src/rev/987db3038ecb
branches:  trunk
changeset: 823210:987db3038ecb
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Sun Apr 16 12:29:20 2017 +0000

description:
Add support for simple fixed-rate clock source bindings.

diffstat:

 sys/dev/fdt/files.fdt    |    6 +-
 sys/dev/fdt/fixedclock.c |  145 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 150 insertions(+), 1 deletions(-)

diffs (169 lines):

diff -r 9cc784ee6cd0 -r 987db3038ecb sys/dev/fdt/files.fdt
--- a/sys/dev/fdt/files.fdt     Sun Apr 16 12:28:21 2017 +0000
+++ b/sys/dev/fdt/files.fdt     Sun Apr 16 12:29:20 2017 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: files.fdt,v 1.8 2017/04/14 22:55:06 jmcneill Exp $
+# $NetBSD: files.fdt,v 1.9 2017/04/16 12:29:20 jmcneill Exp $
 
 include        "external/bsd/libfdt/conf/files.libfdt"
 
@@ -14,6 +14,10 @@
 attach fregulator at fdt
 file   dev/fdt/fixedregulator.c                fregulator
 
+device fclock: clk
+attach fclock at fdt
+file   dev/fdt/fixedclock.c                    fclock
+
 device gpiokeys
 attach gpiokeys at fdt
 file   dev/fdt/gpiokeys.c                      gpiokeys
diff -r 9cc784ee6cd0 -r 987db3038ecb sys/dev/fdt/fixedclock.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/dev/fdt/fixedclock.c  Sun Apr 16 12:29:20 2017 +0000
@@ -0,0 +1,145 @@
+/* $NetBSD: fixedclock.c,v 1.1 2017/04/16 12:29:20 jmcneill Exp $ */
+
+/*-
+ * Copyright (c) 2017 Jared D. 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: fixedclock.c,v 1.1 2017/04/16 12:29:20 jmcneill Exp $");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+#include <sys/kmem.h>
+#include <sys/bus.h>
+
+#include <dev/clk/clk_backend.h>
+
+#include <dev/fdt/fdtvar.h>
+
+static int     fixedclock_match(device_t, cfdata_t, void *);
+static void    fixedclock_attach(device_t, device_t, void *);
+
+static struct clk *fixedclock_decode(device_t, const void *, size_t);
+
+static const struct fdtbus_clock_controller_func fixedclock_fdt_funcs = {
+       .decode = fixedclock_decode
+};
+
+static struct clk *fixedclock_get(void *, const char *);
+static void    fixedclock_put(void *, struct clk *);
+static u_int   fixedclock_get_rate(void *, struct clk *);
+
+static const struct clk_funcs fixedclock_clk_funcs = {
+       .get = fixedclock_get,
+       .put = fixedclock_put,
+       .get_rate = fixedclock_get_rate,
+};
+
+struct fixedclock_clk {
+       struct clk      base;
+       u_int           rate;
+};
+
+struct fixedclock_softc {
+       device_t        sc_dev;
+       int             sc_phandle;
+
+       struct clk_domain sc_clkdom;
+       struct fixedclock_clk sc_clk;
+};
+
+CFATTACH_DECL_NEW(fclock, sizeof(struct fixedclock_softc),
+    fixedclock_match, fixedclock_attach, NULL, NULL);
+
+static int
+fixedclock_match(device_t parent, cfdata_t cf, void *aux)
+{
+       const char * const compatible[] = { "fixed-clock", NULL };
+       const struct fdt_attach_args *faa = aux;
+
+       return of_match_compatible(faa->faa_phandle, compatible);
+}
+
+static void
+fixedclock_attach(device_t parent, device_t self, void *aux)
+{
+       struct fixedclock_softc * const sc = device_private(self);
+       const struct fdt_attach_args *faa = aux;
+       const int phandle = faa->faa_phandle;
+
+       sc->sc_dev = self;
+       sc->sc_phandle = phandle;
+       sc->sc_clkdom.funcs = &fixedclock_clk_funcs;
+       sc->sc_clkdom.priv = sc;
+       if (of_getprop_uint32(phandle, "clock-frequency",
+           &sc->sc_clk.rate) != 0) {
+               aprint_error(": couldn't determine frequency\n");
+               return;
+       }
+       sc->sc_clk.base.domain = &sc->sc_clkdom;
+       sc->sc_clk.base.name = kmem_asprintf("%s", faa->faa_name);
+
+       aprint_naive(": %u Hz fixed clock (%s)\n", sc->sc_clk.rate,
+           sc->sc_clk.base.name);
+
+       fdtbus_register_clock_controller(self, phandle, &fixedclock_fdt_funcs);
+}
+
+static struct clk *
+fixedclock_decode(device_t dev, const void *data, size_t len)
+{
+       struct fixedclock_softc * const sc = device_private(dev);
+
+       /* #clock-cells for a fixed clock is always 0 */
+       if (len != 0)
+               return NULL;
+
+       return &sc->sc_clk.base;
+}
+
+static struct clk *
+fixedclock_get(void *priv, const char *name)
+{
+       struct fixedclock_softc * const sc = priv;
+
+       if (strcmp(name, sc->sc_clk.base.name) != 0)
+               return NULL;
+
+       return &sc->sc_clk.base;
+}
+
+static void
+fixedclock_put(void *priv, struct clk *clk)
+{
+}
+
+static u_int
+fixedclock_get_rate(void *priv, struct clk *clk)
+{
+       struct fixedclock_clk *fclk = (struct fixedclock_clk *)clk;
+
+       return fclk->rate;
+}