brcm2708: organize kernel patches

[openwrt/openwrt.git] / target / linux / brcm2708 / patches-4.19 / 950-0560-clk-bcm2835-Add-support-for-setting-leaf-clock-rates.patch

diff --git a/target/linux/brcm2708/patches-4.19/950-0560-clk-bcm2835-Add-support-for-setting-leaf-clock-rates.patch b/target/linux/brcm2708/patches-4.19/950-0560-clk-bcm2835-Add-support-for-setting-leaf-clock-rates.patch
new file mode 100644 (file)
index 0000000..ca70b9d
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.19/950-0560-clk-bcm2835-Add-support-for-setting-leaf-clock-rates.patch
@@ -0,0 +1,53 @@
+From bf85b92a97a95161d98874571c520fb1395c5aa2 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
+@@ -1097,15 +1097,19 @@ 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);
+ 
+@@ -1475,7 +1479,7 @@ 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.