When changing PLL rate significantly, PLLs have to be reset. Add a function
to perform and check for successful PLL reset.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx>
---
Cc: Mike Turquette <mturquette@xxxxxxxxxx>
Cc: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Cc: Jean-Francois Moine <moinejf@xxxxxxx>
Cc: Michael Welling <mwelling@xxxxxxxx>
Cc: Russell King <rmk+linux@xxxxxxxxxxxxxxxx>
Cc: devicetree@xxxxxxxxxxxxxxx
Cc: linux-clk@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/clk/clk-si5351.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
diff --git a/drivers/clk/clk-si5351.c b/drivers/clk/clk-si5351.c
index beeb57bbb04c..9b97c134e3c1 100644
--- a/drivers/clk/clk-si5351.c
+++ b/drivers/clk/clk-si5351.c
@@ -366,6 +366,32 @@ static const struct clk_ops si5351_vxco_ops = {
* = (MSNx_P1*MSNx_P3 + MSNx_P2 + 512*MSNx_P3)/(128*MSNx_P3)
*
*/
+static int si5351_pll_reset(struct si5351_hw_data *hwdata)
+{
+ unsigned long timeout;
+ u8 mask = (hwdata->num == 0) ?
+ SI5351_STATUS_LOL_A : SI5351_STATUS_LOL_B;
+
+ si5351_reg_write(hwdata->drvdata, SI5351_PLL_RESET,
+ (hwdata->num == 0) ? SI5351_PLL_RESET_A :
+ SI5351_PLL_RESET_B);
+ timeout = jiffies + msecs_to_jiffies(100);
+ do {
+ if ((si5351_reg_read(hwdata->drvdata, SI5351_DEVICE_STATUS) &
+ mask) == 0)
+ break;
+ if (time_after(jiffies, timeout)) {
+ dev_err(&hwdata->drvdata->client->dev,
+ "timeout waiting for pll %d reset\n",
+ hwdata->num);
+ return -EBUSY;
+ };
+ udelay(250);
+ } while (true);
+
+ return 0;
+}
+
static int _si5351_pll_reparent(struct si5351_driver_data *drvdata,
int num, enum si5351_pll_src parent)
{
@@ -519,6 +545,9 @@ static int si5351_pll_set_rate(struct clk_hw *hw, unsigned long rate,
SI5351_CLK_INTEGER_MODE,
(hwdata->params.p2 == 0) ? SI5351_CLK_INTEGER_MODE : 0);
+ /* reset pll after rate change */
+ si5351_pll_reset(hwdata);
+
dev_dbg(&hwdata->drvdata->client->dev,
"%s - %s: p1 = %lu, p2 = %lu, p3 = %lu, parent_rate = %lu, rate = %lu\n",
__func__, __clk_get_name(hwdata->hw.clk),
--
2.1.0
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