diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.19/950-0536-clk-bcm2835-Allow-reparenting-leaf-clocks-while-they.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.19/950-0536-clk-bcm2835-Allow-reparenting-leaf-clocks-while-they.patch | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.19/950-0536-clk-bcm2835-Allow-reparenting-leaf-clocks-while-they.patch b/target/linux/brcm2708/patches-4.19/950-0536-clk-bcm2835-Allow-reparenting-leaf-clocks-while-they.patch new file mode 100644 index 0000000000..490466d7da --- /dev/null +++ b/target/linux/brcm2708/patches-4.19/950-0536-clk-bcm2835-Allow-reparenting-leaf-clocks-while-they.patch @@ -0,0 +1,71 @@ +From d46285327ba5961c992643d468b2862c70f4c7e5 Mon Sep 17 00:00:00 2001 +From: Eric Anholt <eric@anholt.net> +Date: Thu, 2 May 2019 15:24:04 -0700 +Subject: [PATCH] clk: bcm2835: Allow reparenting leaf clocks while + they're running. + +This falls under the same "we can reprogram glitch-free as long as we +pause generation" rule as updating the div/frac fields. This can be +used for runtime reclocking of V3D to manage power leakage. + +Signed-off-by: Eric Anholt <eric@anholt.net> +--- + drivers/clk/bcm/clk-bcm2835.c | 19 ++++++++++++++++--- + 1 file changed, 16 insertions(+), 3 deletions(-) + +--- a/drivers/clk/bcm/clk-bcm2835.c ++++ b/drivers/clk/bcm/clk-bcm2835.c +@@ -1086,8 +1086,10 @@ static int bcm2835_clock_on(struct clk_h + return 0; + } + +-static int bcm2835_clock_set_rate(struct clk_hw *hw, +- unsigned long rate, unsigned long parent_rate) ++static int bcm2835_clock_set_rate_and_parent(struct clk_hw *hw, ++ unsigned long rate, ++ unsigned long parent_rate, ++ u8 parent) + { + struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw); + struct bcm2835_cprman *cprman = clock->cprman; +@@ -1109,6 +1111,11 @@ static int bcm2835_clock_set_rate(struct + bcm2835_clock_wait_busy(clock); + } + ++ if (parent != 0xff) { ++ ctl &= ~(CM_SRC_MASK << CM_SRC_SHIFT); ++ ctl |= parent << CM_SRC_SHIFT; ++ } ++ + ctl &= ~CM_FRAC; + ctl |= (div & CM_DIV_FRAC_MASK) ? CM_FRAC : 0; + cprman_write(cprman, data->ctl_reg, ctl); +@@ -1120,6 +1127,12 @@ static int bcm2835_clock_set_rate(struct + return 0; + } + ++static int bcm2835_clock_set_rate(struct clk_hw *hw, ++ unsigned long rate, unsigned long parent_rate) ++{ ++ return bcm2835_clock_set_rate_and_parent(hw, rate, parent_rate, 0xff); ++} ++ + static bool + bcm2835_clk_is_pllc(struct clk_hw *hw) + { +@@ -1303,6 +1316,7 @@ static const struct clk_ops bcm2835_cloc + .unprepare = bcm2835_clock_off, + .recalc_rate = bcm2835_clock_get_rate, + .set_rate = bcm2835_clock_set_rate, ++ .set_rate_and_parent = bcm2835_clock_set_rate_and_parent, + .determine_rate = bcm2835_clock_determine_rate, + .set_parent = bcm2835_clock_set_parent, + .get_parent = bcm2835_clock_get_parent, +@@ -1479,7 +1493,6 @@ 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_PARENT_GATE; + + /* If the clock wasn't actually enabled at boot, it's not + * critical. |