From: Luc Michel <luc@lmichel.fr>
To: qemu-devel@nongnu.org
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
"Luc Michel" <luc@lmichel.fr>,
"Philippe Mathieu-Daudé" <f4bug@amsat.org>,
"Andrew Baumann" <Andrew.Baumann@microsoft.com>,
"Paul Zimmerman" <pauldzim@gmail.com>,
"Niek Linnenbank" <nieklinnenbank@gmail.com>,
qemu-arm@nongnu.org, "Havard Skinnemoen" <hskinnemoen@google.com>
Subject: [PATCH v3 11/15] hw/misc/bcm2835_cprman: implement clock mux behaviour
Date: Sat, 10 Oct 2020 15:57:55 +0200 [thread overview]
Message-ID: <20201010135759.437903-12-luc@lmichel.fr> (raw)
In-Reply-To: <20201010135759.437903-1-luc@lmichel.fr>
A clock mux can be configured to select one of its 10 sources through
the CM_CTL register. It also embeds yet another clock divider, composed
of an integer part and a fractional part. The number of bits of each
part is mux dependent.
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Luc Michel <luc@lmichel.fr>
---
hw/misc/bcm2835_cprman.c | 53 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 52 insertions(+), 1 deletion(-)
diff --git a/hw/misc/bcm2835_cprman.c b/hw/misc/bcm2835_cprman.c
index b22170f3bc..919a55aa23 100644
--- a/hw/misc/bcm2835_cprman.c
+++ b/hw/misc/bcm2835_cprman.c
@@ -229,19 +229,70 @@ static const TypeInfo cprman_pll_channel_info = {
};
/* clock mux */
+static bool clock_mux_is_enabled(CprmanClockMuxState *mux)
+{
+ return FIELD_EX32(*mux->reg_ctl, CM_CLOCKx_CTL, ENABLE);
+}
+
static void clock_mux_update(CprmanClockMuxState *mux)
{
- clock_update(mux->out, 0);
+ uint64_t freq;
+ uint32_t div, src = FIELD_EX32(*mux->reg_ctl, CM_CLOCKx_CTL, SRC);
+ bool enabled = clock_mux_is_enabled(mux);
+
+ *mux->reg_ctl = FIELD_DP32(*mux->reg_ctl, CM_CLOCKx_CTL, BUSY, enabled);
+
+ if (!enabled) {
+ clock_update(mux->out, 0);
+ return;
+ }
+
+ freq = clock_get_hz(mux->srcs[src]);
+
+ if (mux->int_bits == 0 && mux->frac_bits == 0) {
+ clock_update_hz(mux->out, freq);
+ return;
+ }
+
+ /*
+ * The divider has an integer and a fractional part. The size of each part
+ * varies with the muxes (int_bits and frac_bits). Both parts are
+ * concatenated, with the integer part always starting at bit 12.
+ *
+ * 31 12 11 0
+ * ------------------------------
+ * CM_DIV | | int | frac | |
+ * ------------------------------
+ * <-----> <------>
+ * int_bits frac_bits
+ */
+ div = extract32(*mux->reg_div,
+ R_CM_CLOCKx_DIV_FRAC_LENGTH - mux->frac_bits,
+ mux->int_bits + mux->frac_bits);
+
+ if (!div) {
+ clock_update(mux->out, 0);
+ return;
+ }
+
+ freq = muldiv64(freq, 1 << mux->frac_bits, div);
+
+ clock_update_hz(mux->out, freq);
}
static void clock_mux_src_update(void *opaque)
{
CprmanClockMuxState **backref = opaque;
CprmanClockMuxState *s = *backref;
+ CprmanClockMuxSource src = backref - s->backref;
+
+ if (FIELD_EX32(*s->reg_ctl, CM_CLOCKx_CTL, SRC) != src) {
+ return;
+ }
clock_mux_update(s);
}
static void clock_mux_init(Object *obj)
--
2.28.0
next prev parent reply other threads:[~2020-10-10 14:07 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-10 13:57 [PATCH v3 00/15] raspi: add the bcm2835 cprman clock manager Luc Michel
2020-10-10 13:57 ` [PATCH v3 01/15] hw/core/clock: provide the VMSTATE_ARRAY_CLOCK macro Luc Michel
2020-10-10 13:57 ` [PATCH v3 02/15] hw/core/clock: trace clock values in Hz instead of ns Luc Michel
2020-10-10 15:48 ` Philippe Mathieu-Daudé
2020-10-10 13:57 ` [PATCH v3 03/15] hw/core/clock: add the clock_new helper function Luc Michel
2020-10-10 15:17 ` Philippe Mathieu-Daudé
2020-10-10 15:44 ` Philippe Mathieu-Daudé
2020-10-10 13:57 ` [PATCH v3 04/15] hw/arm/raspi: fix CPRMAN base address Luc Michel
2020-10-10 13:57 ` [PATCH v3 05/15] hw/arm/raspi: add a skeleton implementation of the CPRMAN Luc Michel
2020-10-10 13:57 ` [PATCH v3 06/15] hw/misc/bcm2835_cprman: add a PLL skeleton implementation Luc Michel
2020-10-10 13:57 ` [PATCH v3 07/15] hw/misc/bcm2835_cprman: implement PLLs behaviour Luc Michel
2020-10-10 13:57 ` [PATCH v3 08/15] hw/misc/bcm2835_cprman: add a PLL channel skeleton implementation Luc Michel
2020-10-10 16:05 ` Philippe Mathieu-Daudé
2020-10-17 10:00 ` Philippe Mathieu-Daudé
2020-10-10 13:57 ` [PATCH v3 09/15] hw/misc/bcm2835_cprman: implement PLL channels behaviour Luc Michel
2020-10-10 13:57 ` [PATCH v3 10/15] hw/misc/bcm2835_cprman: add a clock mux skeleton implementation Luc Michel
2020-10-10 13:57 ` Luc Michel [this message]
2020-10-10 15:52 ` [PATCH v3 11/15] hw/misc/bcm2835_cprman: implement clock mux behaviour Philippe Mathieu-Daudé
2020-10-10 13:57 ` [PATCH v3 12/15] hw/misc/bcm2835_cprman: add the DSI0HSCK multiplexer Luc Michel
2020-10-10 13:57 ` [PATCH v3 13/15] hw/misc/bcm2835_cprman: add sane reset values to the registers Luc Michel
2020-10-10 16:18 ` Philippe Mathieu-Daudé
2020-10-11 18:26 ` Luc Michel
2020-10-16 17:10 ` Philippe Mathieu-Daudé
2020-10-19 15:44 ` Philippe Mathieu-Daudé
2020-10-10 13:57 ` [PATCH v3 14/15] hw/char/pl011: add a clock input Luc Michel
2020-10-10 13:57 ` [PATCH v3 15/15] hw/arm/bcm2835_peripherals: connect the UART clock Luc Michel
2020-10-16 17:11 ` [PATCH v3 00/15] raspi: add the bcm2835 cprman clock manager Philippe Mathieu-Daudé
2020-10-19 15:45 ` Peter Maydell
2020-10-19 19:31 ` Peter Maydell
2020-10-27 8:55 ` Philippe Mathieu-Daudé
2020-10-27 11:11 ` Peter Maydell
2020-10-22 22:06 ` Philippe Mathieu-Daudé
2020-10-22 22:48 ` Guenter Roeck
2020-10-23 3:55 ` Guenter Roeck
2020-10-23 11:13 ` Philippe Mathieu-Daudé
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201010135759.437903-12-luc@lmichel.fr \
--to=luc@lmichel.fr \
--cc=Andrew.Baumann@microsoft.com \
--cc=f4bug@amsat.org \
--cc=hskinnemoen@google.com \
--cc=nieklinnenbank@gmail.com \
--cc=pauldzim@gmail.com \
--cc=peter.maydell@linaro.org \
--cc=qemu-arm@nongnu.org \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).