[PATCH 5.4 33/90] clk: sunxi-ng: h6-r: Fix AR100/R_APB2 parent order

Greg Kroah-Hartman
2020-02-03T16:41:30Z

From: Samuel Holland <samuel@sholland.org>

[ Upstream commit 0c545240aebc2ccb8f661dc54283a14d64659804 ]

According to the BSP source code, both the AR100 and R_APB2 clocks have
PLL_PERIPH0 as mux index 3, not 2 as it was on previous chips. The pre-
divider used for PLL_PERIPH0 should be changed to index 3 to match.

This was verified by running a rough benchmark on the AR100 with various
clock settings:

| mux | pre-divider | iterations/second | clock source |
|=====|=============|===================|==============|
| 0 | 0 | 19033 (stable) | osc24M |
| 2 | 5 | 11466 (unstable) | iosc/osc16M |
| 2 | 17 | 11422 (unstable) | iosc/osc16M |
| 3 | 5 | 85338 (stable) | pll-periph0 |
| 3 | 17 | 27167 (stable) | pll-periph0 |

The relative performance numbers all match up (with pll-periph0 running
at its default 600MHz).

Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c b/drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c
index 45a1ed3fe6742..ab194143e06ce 100644
--- a/drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c
+++ b/drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c
@@ -23,9 +23,9 @@
*/

static const char * const ar100_r_apb2_parents[] = { "osc24M", "osc32k",
- "pll-periph0", "iosc" };
+ "iosc", "pll-periph0" };
static const struct ccu_mux_var_prediv ar100_r_apb2_predivs[] = {
- { .index = 2, .shift = 0, .width = 5 },
+ { .index = 3, .shift = 0, .width = 5 },
};

static struct ccu_div ar100_clk = {
--
2.20.1