openwrt/target/linux/bcm27xx/patches-5.4/950-0219-clk-bcm2835-Add-support-for-setting-leaf-clock-rates.patch
John Audia b4c02c9998 kernel: bump 5.4 to 5.4.73
Removed upstreamed patches:
 generic/pending-5.4
   445-mtd-spinand-gigadevice-Only-one-dummy-byte-in-QUA.patch
   446-mtd-spinand-gigadevice-Add-QE-Bit.patch
 pistachio/patches-5.4
   150-pwm-img-Fix-null-pointer-access-in-probe.patch

Manually rebased:
 layerscape/patches-5.4
   801-audio-0011-Revert-ASoC-fsl_sai-add-of_match-data.patch
   801-audio-0039-MLK-16224-6-ASoC-fsl_sai-fix-DSD-suspend-resume.patch
   801-audio-0073-MLK-21957-3-ASoC-fsl_sai-add-bitcount-and-timestamp-.patch
   820-usb-0009-usb-dwc3-Add-workaround-for-host-mode-VBUS-glitch-wh.patch

All modifications made by update_kernel.sh

Build system: x86_64
Build-tested: ipq806x/R7800, ath79/generic, bcm27xx/bcm2711,
              mvebu (mamba, rango), x86_64, ramips/mt7621
Run-tested: ipq806x/R7800, mvebu (mamba, rango), x86_64, ramips (RT-AC57U)

No dmesg regressions, everything functional

Signed-off-by: John Audia <graysky@archlinux.us>
[alter 820-usb-0009-usb-dwc3-Add-workaround-for-host-mode-VBUS-glitch-wh]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
2020-11-01 14:44:06 +01:00

54 lines
1.8 KiB
Diff

From cfe0832e8306cd9955f682b7314a5a6fc3b9d514 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Thu, 2 May 2019 15:11:05 -0700
Subject: [PATCH] clk: bcm2835: Add support for setting leaf clock
rates while running.
As long as you wait for !BUSY, you can do glitch-free updates of clock
rate while the clock is running.
Signed-off-by: Eric Anholt <eric@anholt.net>
---
drivers/clk/bcm/clk-bcm2835.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1114,15 +1114,19 @@ static int bcm2835_clock_set_rate(struct
spin_lock(&cprman->regs_lock);
- /*
- * Setting up frac support
- *
- * In principle it is recommended to stop/start the clock first,
- * but as we set CLK_SET_RATE_GATE during registration of the
- * clock this requirement should be take care of by the
- * clk-framework.
+ ctl = cprman_read(cprman, data->ctl_reg);
+
+ /* If the clock is running, we have to pause clock generation while
+ * updating the control and div regs. This is glitchless (no clock
+ * signals generated faster than the rate) but each reg access is two
+ * OSC cycles so the clock will slow down for a moment.
*/
- ctl = cprman_read(cprman, data->ctl_reg) & ~CM_FRAC;
+ if (ctl & CM_ENABLE) {
+ cprman_write(cprman, data->ctl_reg, ctl & ~CM_ENABLE);
+ bcm2835_clock_wait_busy(clock);
+ }
+
+ ctl &= ~CM_FRAC;
ctl |= (div & CM_DIV_FRAC_MASK) ? CM_FRAC : 0;
cprman_write(cprman, data->ctl_reg, ctl);
@@ -1494,7 +1498,7 @@ static struct clk_hw *bcm2835_register_c
init.ops = &bcm2835_vpu_clock_clk_ops;
} else {
init.ops = &bcm2835_clock_clk_ops;
- init.flags |= CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
+ init.flags |= CLK_SET_PARENT_GATE;
/* If the clock wasn't actually enabled at boot, it's not
* critical.