For gapless tuning, there is no need for PLL reset and clkout power-down
when tuning output. "silabs,gapless-tuning" parameter enables gapless tuning
for specific clock output.
Signed-off-by: Michal Bachraty <michal.bachr...@streamunlimited.com>
---
.../devicetree/bindings/clock/silabs,si5351.txt | 2 ++
drivers/clk/clk-si5351.c | 27 +++++++++++++++++---
2 files changed, 25 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/clock/silabs,si5351.txt
b/Documentation/devicetree/bindings/clock/silabs,si5351.txt
index cc37465..e16ab2b 100644
--- a/Documentation/devicetree/bindings/clock/silabs,si5351.txt
+++ b/Documentation/devicetree/bindings/clock/silabs,si5351.txt
@@ -44,6 +44,8 @@ Optional child node properties:
- silabs,multisynth-source: source pll A(0) or B(1) of corresponding multisynth
divider.
- silabs,pll-master: boolean, multisynth can change pll frequency.
+- silabs,gapless-tuning: boolean, enable gapless (glitch-free) tuning. Depends
on
+ "silabs,multisynth-source" parameter.
==Example==
diff --git a/drivers/clk/clk-si5351.c b/drivers/clk/clk-si5351.c
index e259cec..d3933a9 100644
--- a/drivers/clk/clk-si5351.c
+++ b/drivers/clk/clk-si5351.c
@@ -54,6 +54,7 @@ struct si5351_hw_data {
struct si5351_driver_data *drvdata;
struct si5351_parameters params;
unsigned char num;
+ unsigned char gapless_tuning;
};
struct si5351_driver_data {
@@ -526,8 +527,10 @@ static int si5351_pll_set_rate(struct clk_hw *hw, unsigned
long rate,
(hwdata->params.p2 == 0) ? SI5351_CLK_INTEGER_MODE : 0);
/* reset pll */
- val = (hwdata->num == 0) ? SI5351_PLL_RESET_A : SI5351_PLL_RESET_B;
- si5351_set_bits(hwdata->drvdata, SI5351_PLL_RESET, val, val);
+ if (!hwdata->gapless_tuning) {
+ val = (hwdata->num == 0) ? SI5351_PLL_RESET_A :
SI5351_PLL_RESET_B;
+ si5351_set_bits(hwdata->drvdata, SI5351_PLL_RESET, val, val);
+ }
dev_dbg(&hwdata->drvdata->client->dev,
"%s - %s: p1 = %lu, p2 = %lu, p3 = %lu, parent_rate = %lu, rate
= %lu\n",
@@ -1064,8 +1067,9 @@ static int si5351_clkout_set_rate(struct clk_hw *hw,
unsigned long rate,
} while (1);
/* powerdown clkout */
- si5351_set_bits(hwdata->drvdata, SI5351_CLK0_CTRL + hwdata->num,
- SI5351_CLK_POWERDOWN, SI5351_CLK_POWERDOWN);
+ if (!hwdata->gapless_tuning)
+ si5351_set_bits(hwdata->drvdata, SI5351_CLK0_CTRL + hwdata->num,
+ SI5351_CLK_POWERDOWN, SI5351_CLK_POWERDOWN);
/* write output divider */
switch (hwdata->num) {
@@ -1117,6 +1121,7 @@ static void si5351_dt_setup(
struct property *prop;
const __be32 *p;
unsigned int num, val;
+ int pll = -1;
if (np == NULL)
return;
@@ -1167,6 +1172,8 @@ static void si5351_dt_setup(
dev_warn(&client->dev,
"unable to reparent multisynth %d to
%d\n",
num, val);
+ else
+ pll = val;
}
if (!of_property_read_u32(np, "silabs,clock-source", &val)) {
@@ -1178,6 +1185,15 @@ static void si5351_dt_setup(
if (!of_property_read_u32(np, "clock-frequency", &val))
clk_set_rate(drvdata->onecell.clks[num], val);
+
+ if (of_property_read_bool(np, "silabs,gapless-tuning")) {
+ if (pll >= 0) {
+ drvdata->clkout[num].gapless_tuning = 1;
+ drvdata->pll[pll].gapless_tuning = 1;
+ } else
+ dev_warn(&client->dev,
+ "unable to set gapless tuning");
+ }
}
}
@@ -1294,6 +1310,7 @@ static int si5351_i2c_probe(struct i2c_client *client,
drvdata->pll[0].num = 0;
drvdata->pll[0].drvdata = drvdata;
drvdata->pll[0].hw.init = &init;
+ drvdata->pll[0].gapless_tuning = 0;
memset(&init, 0, sizeof(init));
init.name = si5351_pll_names[0];
init.ops = &si5351_pll_ops;
@@ -1310,6 +1327,7 @@ static int si5351_i2c_probe(struct i2c_client *client,
drvdata->pll[1].num = 1;
drvdata->pll[1].drvdata = drvdata;
drvdata->pll[1].hw.init = &init;
+ drvdata->pll[1].gapless_tuning = 0;
memset(&init, 0, sizeof(init));
if (drvdata->variant == SI5351_VARIANT_B) {
init.name = si5351_pll_names[2];
@@ -1380,6 +1398,7 @@ static int si5351_i2c_probe(struct i2c_client *client,
drvdata->clkout[n].num = n;
drvdata->clkout[n].drvdata = drvdata;
drvdata->clkout[n].hw.init = &init;
+ drvdata->clkout[n].gapless_tuning = 0;
memset(&init, 0, sizeof(init));
init.name = si5351_clkout_names[n];
init.ops = &si5351_clkout_ops;
--
1.7.9.5
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