[src/trunk]: src/sys/dev/fdt Add driver for fixed-factor clocks.

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

details:   https://anonhg.NetBSD.org/src/rev/cc7f6232bda2
branches:  trunk
changeset: 825310:cc7f6232bda2
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Sat Jul 08 12:37:08 2017 +0000

description:
Add driver for fixed-factor clocks.

diffstat:

 sys/dev/fdt/files.fdt          |    6 +-
 sys/dev/fdt/fixedfactorclock.c |  164 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 169 insertions(+), 1 deletions(-)

diffs (188 lines):

diff -r 904e99167f4c -r cc7f6232bda2 sys/dev/fdt/files.fdt
--- a/sys/dev/fdt/files.fdt     Sat Jul 08 12:36:51 2017 +0000
+++ b/sys/dev/fdt/files.fdt     Sat Jul 08 12:37:08 2017 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: files.fdt,v 1.18 2017/07/08 00:55:02 jmcneill Exp $
+# $NetBSD: files.fdt,v 1.19 2017/07/08 12:37:08 jmcneill Exp $
 
 include        "external/bsd/libfdt/conf/files.libfdt"
 
@@ -18,6 +18,10 @@
 attach fclock at fdt
 file   dev/fdt/fixedclock.c                    fclock
 
+device ffclock: clk
+attach ffclock at fdt
+file   dev/fdt/fixedfactorclock.c              ffclock
+
 device gpiokeys: sysmon_envsys, sysmon_power
 attach gpiokeys at fdt
 file   dev/fdt/gpiokeys.c                      gpiokeys
diff -r 904e99167f4c -r cc7f6232bda2 sys/dev/fdt/fixedfactorclock.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/dev/fdt/fixedfactorclock.c    Sat Jul 08 12:37:08 2017 +0000
@@ -0,0 +1,164 @@
+/* $NetBSD: fixedfactorclock.c,v 1.1 2017/07/08 12:37:08 jmcneill Exp $ */
+
+/*-
+ * Copyright (c) 2017 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: fixedfactorclock.c,v 1.1 2017/07/08 12:37:08 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     fixedfactorclock_match(device_t, cfdata_t, void *);
+static void    fixedfactorclock_attach(device_t, device_t, void *);
+
+static struct clk *fixedfactorclock_decode(device_t, const void *, size_t);
+
+static const struct fdtbus_clock_controller_func fixedfactorclock_fdt_funcs = {
+       .decode = fixedfactorclock_decode
+};
+
+static struct clk *fixedfactorclock_get(void *, const char *);
+static void    fixedfactorclock_put(void *, struct clk *);
+static u_int   fixedfactorclock_get_rate(void *, struct clk *);
+
+static const struct clk_funcs fixedfactorclock_clk_funcs = {
+       .get = fixedfactorclock_get,
+       .put = fixedfactorclock_put,
+       .get_rate = fixedfactorclock_get_rate,
+};
+
+struct fixedfactorclock_clk {
+       struct clk      base;
+
+       u_int           div;
+       u_int           mult;
+};
+
+struct fixedfactorclock_softc {
+       device_t        sc_dev;
+       int             sc_phandle;
+
+       struct clk_domain sc_clkdom;
+       struct fixedfactorclock_clk sc_clk;
+};
+
+CFATTACH_DECL_NEW(ffclock, sizeof(struct fixedfactorclock_softc),
+    fixedfactorclock_match, fixedfactorclock_attach, NULL, NULL);
+
+static int
+fixedfactorclock_match(device_t parent, cfdata_t cf, void *aux)
+{
+       const char * const compatible[] = { "fixed-factor-clock", NULL };
+       const struct fdt_attach_args *faa = aux;
+
+       return of_match_compatible(faa->faa_phandle, compatible);
+}
+
+static void
+fixedfactorclock_attach(device_t parent, device_t self, void *aux)
+{
+       struct fixedfactorclock_softc * const sc = device_private(self);
+       const struct fdt_attach_args *faa = aux;
+       const int phandle = faa->faa_phandle;
+       const char *name;
+
+       sc->sc_dev = self;
+       sc->sc_phandle = phandle;
+       sc->sc_clkdom.funcs = &fixedfactorclock_clk_funcs;
+       sc->sc_clkdom.priv = sc;
+
+       of_getprop_uint32(phandle, "clock-div", &sc->sc_clk.div);
+       of_getprop_uint32(phandle, "clock-mult", &sc->sc_clk.mult);
+
+       if (sc->sc_clk.div == 0 || sc->sc_clk.mult == 0) {
+               aprint_error(": invalid properties\n");
+               return;
+       }
+
+       name = fdtbus_get_string(phandle, "clock-output-names");
+       if (name == NULL)
+               name = faa->faa_name;
+
+       sc->sc_clk.base.domain = &sc->sc_clkdom;
+       sc->sc_clk.base.name = name;
+
+       aprint_naive("\n");
+       aprint_normal(": x%u /%u fixed-factor clock\n",
+           sc->sc_clk.mult, sc->sc_clk.div);
+
+       fdtbus_register_clock_controller(self, phandle,
+           &fixedfactorclock_fdt_funcs);
+}
+
+static struct clk *
+fixedfactorclock_decode(device_t dev, const void *data, size_t len)
+{
+       struct fixedfactorclock_softc * const sc = device_private(dev);
+
+       /* #clock-cells for a fixed factor clock is always 0 */
+       if (len != 0)
+               return NULL;
+
+       return &sc->sc_clk.base;
+}
+
+static struct clk *
+fixedfactorclock_get(void *priv, const char *name)
+{
+       struct fixedfactorclock_softc * const sc = priv;
+
+       if (strcmp(name, sc->sc_clk.base.name) != 0)
+               return NULL;
+
+       return &sc->sc_clk.base;
+}
+
+static void
+fixedfactorclock_put(void *priv, struct clk *clk)
+{
+}
+
+static u_int
+fixedfactorclock_get_rate(void *priv, struct clk *clk)
+{
+       struct fixedfactorclock_softc * const sc = priv;
+       struct fixedfactorclock_clk *fclk = (struct fixedfactorclock_clk *)clk;
+       struct clk *clkp_parent;
+
+       clkp_parent = fdtbus_clock_get_index(sc->sc_phandle, 0);
+       if (clkp_parent == NULL)
+               return 0;
+
+       return (clk_get_rate(clkp_parent) * fclk->mult) / fclk->div;
+}