clk: Support bypassing dividers

When a clock is declared as both CGU_CLK_DIV and CGU_CLK_MUX, the CGU
code expects the mux to be applied first, the divider second.

On the JZ4760, and maybe on some other SoCs, some clocks also have a mux
setting and a divider, but the divider is not applied to all parents
selectable from the mux.

This could be solved by creating two clocks, one with CGU_CLK_DIV and
one with CGU_CLK_MUX, but that would increase the number of clocks.

Instead, add a 8-bit mask to CGU_CLK_DIV clocks. If the bit
corresponding to the parent clock's index is set, the divider is
bypassed.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20210530164923.18134-3-paul@crapouillou.net
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/clk/ingenic/cgu.h b/drivers/clk/ingenic/cgu.h
index 2c75ef4a36f5..44d97a259692 100644
--- a/drivers/clk/ingenic/cgu.h
+++ b/drivers/clk/ingenic/cgu.h
@@ -84,6 +84,7 @@ struct ingenic_cgu_mux_info {
  *          isn't one
  * @busy_bit: the index of the busy bit within reg, or -1 if there isn't one
  * @stop_bit: the index of the stop bit within reg, or -1 if there isn't one
+ * @bypass_mask: mask of parent clocks for which the divider does not apply
  * @div_table: optional table to map the value read from the register to the
  *             actual divider value
  */
@@ -95,6 +96,7 @@ struct ingenic_cgu_div_info {
 	s8 ce_bit;
 	s8 busy_bit;
 	s8 stop_bit;
+	u8 bypass_mask;
 	const u8 *div_table;
 };