diff mbox

[V3,1/6] clk: bcm2835: the minimum clock divider is 2

Message ID 1452779142-20615-2-git-send-email-kernel@martin.sperl.org (mailing list archive)
State New, archived
Headers show

Commit Message

Martin Sperl Jan. 14, 2016, 1:45 p.m. UTC 
From: Martin Sperl <kernel@martin.sperl.org>

Testing with different clock divider values has shown
that (at least for the PCM clock) the clock divider
has to be at least 2, otherwise the clock will not
output a signal.

So the clamping has changed from 1 to 2 and comments
about the kind of clamping applied have been added.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
---
 drivers/clk/bcm/clk-bcm2835.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 015e687..10e97b7 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1178,7 +1178,11 @@  static u32 bcm2835_clock_choose_div(struct clk_hw *hw,
 	div &= ~unused_frac_mask;
 
 	/* Clamp to the limits. */
-	div = max(div, unused_frac_mask + 1);
+
+	/* divider must be >= 2 */
+	div = max_t(u32, div, (2 << CM_DIV_FRAC_BITS));
+
+	/* clamp to max divider allowed */
 	div = min_t(u32, div, GENMASK(data->int_bits + CM_DIV_FRAC_BITS - 1,
 				      CM_DIV_FRAC_BITS - data->frac_bits));