diff mbox series

[v2,03/15] clk: sunxi-ng: Add check for maximum rate to NKM PLLs

Message ID 20181023155035.9101-4-jagan@amarulasolutions.com (mailing list archive)
State New, archived
Headers show
Series drm/sun4i: Allwinner A64 MIPI-DSI support | expand

Commit Message

Jagan Teki Oct. 23, 2018, 3:50 p.m. UTC
Some NKM PLLs, frequency can be set above PLL working range.

Add a constraint for maximum supported rate. This way, drivers can
specify which is maximum allowed rate for PLL.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
Changes for v2:
- new patch

 drivers/clk/sunxi-ng/ccu_nkm.c | 7 +++++++
 drivers/clk/sunxi-ng/ccu_nkm.h | 1 +
 2 files changed, 8 insertions(+)

Comments

Stephen Boyd Oct. 24, 2018, 8:48 a.m. UTC | #1
Quoting Jagan Teki (2018-10-23 08:50:23)
> Some NKM PLLs, frequency can be set above PLL working range.
> 
> Add a constraint for maximum supported rate. This way, drivers can
> specify which is maximum allowed rate for PLL.
> 
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---

Acked-by: Stephen Boyd <sboyd@kernel.org>
diff mbox series

Patch

diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
index d17539dc88dd..574fd2cd2a79 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.c
+++ b/drivers/clk/sunxi-ng/ccu_nkm.c
@@ -132,6 +132,13 @@  static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
 		return rate;
 	}
 
+	if (nkm->max_rate && rate > nkm->max_rate) {
+		rate = nkm->max_rate;
+		if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+			rate /= nkm->fixed_post_div;
+		return rate;
+	}
+
 	ccu_nkm_find_best(*parent_rate, rate, &_nkm);
 
 	rate = *parent_rate * _nkm.n * _nkm.k / _nkm.m;
diff --git a/drivers/clk/sunxi-ng/ccu_nkm.h b/drivers/clk/sunxi-ng/ccu_nkm.h
index ff5bd00f429f..c82590481188 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.h
+++ b/drivers/clk/sunxi-ng/ccu_nkm.h
@@ -36,6 +36,7 @@  struct ccu_nkm {
 
 	unsigned int		fixed_post_div;
 	unsigned int		min_rate;
+	unsigned int		max_rate;
 
 	struct ccu_common	common;
 };