Re: [PATCH v2] clk: si5351: Add PLL soft reset

From: Sebastian Hesselbarth
Date: Fri Nov 20 2015 - 12:55:37 EST

On 20.11.2015 18:22, Jacob Siverskog wrote:
This is according to figure 12 ("I2C Programming Procedure") in
"Si5351A/B/C Data Sheet"

Without the PLL soft reset, we were unable to get three outputs
working at the same time.

According to Silicon Labs support, performing PLL soft reset will only
be noticeable if the PLL parameters have been changed.

Signed-off-by: Jacob Siverskog <jacob@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jens Rudberg <jens@xxxxxxxxxxxxxxxxxxx>
drivers/clk/clk-si5351.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/clk/clk-si5351.c b/drivers/clk/clk-si5351.c
index e346b22..984c058 100644
--- a/drivers/clk/clk-si5351.c
+++ b/drivers/clk/clk-si5351.c
@@ -1091,6 +1091,12 @@ static int si5351_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
si5351_set_bits(hwdata->drvdata, SI5351_CLK0_CTRL + hwdata->num,

+ /* do a pll soft reset on both plls, needed in some cases to get all
+ * outputs running
+ */

Common convention for multi-line comments usually is:

* Do a PLL soft reset on both PLLs required to get
* all outputs running.

After you fixed the style issue, you can add my

Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx>


+ si5351_reg_write(hwdata->drvdata, SI5351_PLL_RESET,
"%s - %s: rdiv = %u, parent_rate = %lu, rate = %lu\n",
__func__, clk_hw_get_name(hw), (1 << rdiv),

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at