[PATCH v3 4/9] clk: si5341: Check for input clock presence and PLL lock on startup
From: Robert Hancock <hidden>
Date: 2021-03-25 19:28:53
Also in:
linux-clk
Subsystem:
common clk framework, the rest · Maintainers:
Michael Turquette, Stephen Boyd, Linus Torvalds
After initializing the device, wait for it to report that the input
clock is present and the PLL has locked before declaring success.
Fixes: 3044a860fd ("clk: Add Si5341/Si5340 driver")
Signed-off-by: Robert Hancock <redacted>
---
drivers/clk/clk-si5341.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c
index ac1ccec2b681..da40b90c2aa8 100644
--- a/drivers/clk/clk-si5341.c
+++ b/drivers/clk/clk-si5341.c@@ -92,6 +92,9 @@ struct clk_si5341_output_config { #define SI5341_PN_BASE 0x0002 #define SI5341_DEVICE_REV 0x0005 #define SI5341_STATUS 0x000C +#define SI5341_LOS 0x000D +#define SI5341_STATUS_STICKY 0x0011 +#define SI5341_LOS_STICKY 0x0012 #define SI5341_SOFT_RST 0x001C #define SI5341_IN_SEL 0x0021 #define SI5341_DEVICE_READY 0x00FE
@@ -99,6 +102,12 @@ struct clk_si5341_output_config { #define SI5341_IN_EN 0x0949 #define SI5341_INX_TO_PFD_EN 0x094A +/* Status bits */ +#define SI5341_STATUS_SYSINCAL BIT(0) +#define SI5341_STATUS_LOSXAXB BIT(1) +#define SI5341_STATUS_LOSREF BIT(2) +#define SI5341_STATUS_LOL BIT(3) + /* Input selection */ #define SI5341_IN_SEL_MASK 0x06 #define SI5341_IN_SEL_SHIFT 1
@@ -1416,6 +1425,7 @@ static int si5341_probe(struct i2c_client *client, unsigned int i; struct clk_si5341_output_config config[SI5341_MAX_NUM_OUTPUTS]; bool initialization_required; + u32 status; data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); if (!data)
@@ -1583,6 +1593,22 @@ static int si5341_probe(struct i2c_client *client, return err; } + /* wait for device to report input clock present and PLL lock */ + err = regmap_read_poll_timeout(data->regmap, SI5341_STATUS, status, + !(status & (SI5341_STATUS_LOSREF | SI5341_STATUS_LOL)), + 10000, 250000); + if (err) { + dev_err(&client->dev, "Error waiting for input clock or PLL lock\n"); + return err; + } + + /* clear sticky alarm bits from initialization */ + err = regmap_write(data->regmap, SI5341_STATUS_STICKY, 0); + if (err) { + dev_err(&client->dev, "unable to clear sticky status\n"); + return err; + } + /* Free the names, clk framework makes copies */ for (i = 0; i < data->num_synth; ++i) devm_kfree(&client->dev, (void *)synth_clock_names[i]);
--
2.27.0