[PATCH 5.10 068/593] clk: agilex/stratix10/n5x: fix how the bypass_reg is handled

From: Greg Kroah-Hartman
Date: Mon Jul 12 2021 - 02:42:56 EST


From: Dinh Nguyen <dinguyen@xxxxxxxxxx>

commit dfd1427c3769ba51297777dbb296f1802d72dbf6 upstream.

If the bypass_reg is set, then we can return the bypass parent, however,
if there is not a bypass_reg, we need to figure what the correct parent
mux is.

The previous code never handled the parent mux if there was a
bypass_reg.

Fixes: 80c6b7a0894f ("clk: socfpga: agilex: add clock driver for the Agilex platform")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Dinh Nguyen <dinguyen@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210611025201.118799-4-dinguyen@xxxxxxxxxx
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/clk/socfpga/clk-periph-s10.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

--- a/drivers/clk/socfpga/clk-periph-s10.c
+++ b/drivers/clk/socfpga/clk-periph-s10.c
@@ -49,16 +49,21 @@ static u8 clk_periclk_get_parent(struct
{
struct socfpga_periph_clk *socfpgaclk = to_periph_clk(hwclk);
u32 clk_src, mask;
- u8 parent;
+ u8 parent = 0;

+ /* handle the bypass first */
if (socfpgaclk->bypass_reg) {
mask = (0x1 << socfpgaclk->bypass_shift);
parent = ((readl(socfpgaclk->bypass_reg) & mask) >>
socfpgaclk->bypass_shift);
- } else {
+ if (parent)
+ return parent;
+ }
+
+ if (socfpgaclk->hw.reg) {
clk_src = readl(socfpgaclk->hw.reg);
parent = (clk_src >> CLK_MGR_FREE_SHIFT) &
- CLK_MGR_FREE_MASK;
+ CLK_MGR_FREE_MASK;
}
return parent;
}