[PATCH v3 0/9] Si5341 driver updates

[PATCH v3 0/9] Si5341 driver updates

[Robert Hancock]

Various fixes and enhancements to the Si5341 driver.

Changed since v2:
-changed regulator reference for output supply from vdd to vddo to match
data sheet

Changed since v1:
-wait up to 300ms for DEVICE_READY
-use regmap_read_poll_timeout rather than fixed wait when waiting for PLL
lock and input presence
-make si5341_remove static

Robert Hancock (9):
  dt-bindings: clock: clk-si5341: Add new attributes
  clk: si5341: Wait for DEVICE_READY on startup
  clk: si5341: Avoid divide errors due to bogus register contents
  clk: si5341: Check for input clock presence and PLL lock on startup
  clk: si5341: Update initialization magic
  clk: si5341: Allow different output VDD_SEL values
  clk: si5341: Add silabs,xaxb-ext-clk property
  clk: si5341: Add silabs,iovdd-33 property
  clk: si5341: Add sysfs properties to allow checking/resetting device
    faults

 .../bindings/clock/silabs,si5341.txt          |  16 +-
 drivers/clk/clk-si5341.c                      | 324 ++++++++++++++++--
 2 files changed, 304 insertions(+), 36 deletions(-)

-- 
2.27.0

[PATCH v3 1/9] dt-bindings: clock: clk-si5341: Add new attributes

[Robert Hancock]

Add new silabs,xaxb-ext-clk and silabs,iovdd-33 properties.

Changed vdd-supply on top-level node to optional since it is not actually
used by the driver.

Removed vdd-supply from output sub-nodes, as it was not supported by the
driver and it is not easily possible to support this in that location with
the kernel regulator infrastructure. Changed to have vddoX-supply
attributes for each output on the top-level device node.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 .../devicetree/bindings/clock/silabs,si5341.txt  | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/clock/silabs,si5341.txt b/Documentation/devicetree/bindings/clock/silabs,si5341.txt
index 504cce3abe46..ce55aba0ce22 100644
--- a/Documentation/devicetree/bindings/clock/silabs,si5341.txt
+++ b/Documentation/devicetree/bindings/clock/silabs,si5341.txt
@@ -24,9 +24,8 @@ it.
 
 The device type, speed grade and revision are determined runtime by probing.
 
-The driver currently only supports XTAL input mode, and does not support any
-fancy input configurations. They can still be programmed into the chip and
-the driver will leave them "as is".
+The driver currently does not support any fancy input configurations. They can
+still be programmed into the chip and the driver will leave them "as is".
 
 ==I2C device node==
 
@@ -45,9 +44,9 @@ Required properties:
 	corresponding to inputs. Use a fixed clock for the "xtal" input.
 	At least one must be present.
 - clock-names: One of: "xtal", "in0", "in1", "in2"
-- vdd-supply: Regulator node for VDD
 
 Optional properties:
+- vdd-supply: Regulator node for VDD
 - vdda-supply: Regulator node for VDDA
 - vdds-supply: Regulator node for VDDS
 - silabs,pll-m-num, silabs,pll-m-den: Numerator and denominator for PLL
@@ -60,7 +59,14 @@ Optional properties:
   be initialized, and always performs the soft-reset routine. Since this will
   temporarily stop all output clocks, don't do this if the chip is generating
   the CPU clock for example.
+- silabs,xaxb-ext-clk: When present, indicates that the XA/XB pins are used
+  in EXTCLK (external reference clock) rather than XTAL (crystal) mode.
 - interrupts: Interrupt for INTRb pin.
+- silabs,iovdd-33: When present, indicates that the I2C lines are using 3.3V
+  rather than 1.8V thresholds.
+- vddoX-supply (where X is an output index): Regulator node for VDDO for the
+  specified output. The driver selects the output VDD_SEL setting based on this
+  voltage.
 - #address-cells: shall be set to 1.
 - #size-cells: shall be set to 0.
 
@@ -77,8 +83,6 @@ Required child node properties:
 - reg: number of clock output.
 
 Optional child node properties:
-- vdd-supply: Regulator node for VDD for this output. The driver selects default
-	values for common-mode and amplitude based on the voltage.
 - silabs,format: Output format, one of:
 	1 = differential (defaults to LVDS levels)
 	2 = low-power (defaults to HCSL levels)
-- 
2.27.0

[PATCH v3 2/9] clk: si5341: Wait for DEVICE_READY on startup

[Robert Hancock]

The Si5341 datasheet warns that before accessing any other registers,
including the PAGE register, we need to wait for the DEVICE_READY register
to indicate the device is ready, or the process of the device loading its
state from NVM can be corrupted. Wait for DEVICE_READY on startup before
continuing initialization. This is done using a raw I2C register read
prior to setting up regmap to avoid any potential unwanted automatic PAGE
register accesses from regmap at this stage.

Fixes: 3044a860fd ("clk: Add Si5341/Si5340 driver")
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 drivers/clk/clk-si5341.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c
index e0446e66fa64..b8a960e927bc 100644
--- a/drivers/clk/clk-si5341.c
+++ b/drivers/clk/clk-si5341.c
@@ -94,6 +94,7 @@ struct clk_si5341_output_config {
 #define SI5341_STATUS		0x000C
 #define SI5341_SOFT_RST		0x001C
 #define SI5341_IN_SEL		0x0021
+#define SI5341_DEVICE_READY	0x00FE
 #define SI5341_XAXB_CFG		0x090E
 #define SI5341_IN_EN		0x0949
 #define SI5341_INX_TO_PFD_EN	0x094A
@@ -1189,6 +1190,32 @@ static const struct regmap_range_cfg si5341_regmap_ranges[] = {
 	},
 };
 
+static int si5341_wait_device_ready(struct i2c_client *client)
+{
+	int count;
+
+	/* Datasheet warns: Any attempt to read or write any register other
+	 * than DEVICE_READY before DEVICE_READY reads as 0x0F may corrupt the
+	 * NVM programming and may corrupt the register contents, as they are
+	 * read from NVM. Note that this includes accesses to the PAGE register.
+	 * Also: DEVICE_READY is available on every register page, so no page
+	 * change is needed to read it.
+	 * Do this outside regmap to avoid automatic PAGE register access.
+	 * May take up to 300ms to complete.
+	 */
+	for (count = 0; count < 15; ++count) {
+		s32 result = i2c_smbus_read_byte_data(client,
+						      SI5341_DEVICE_READY);
+		if (result < 0)
+			return result;
+		if (result == 0x0F)
+			return 0;
+		msleep(20);
+	}
+	dev_err(&client->dev, "timeout waiting for DEVICE_READY\n");
+	return -EIO;
+}
+
 static const struct regmap_config si5341_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
@@ -1385,6 +1412,11 @@ static int si5341_probe(struct i2c_client *client,
 
 	data->i2c_client = client;
 
+	/* Must be done before otherwise touching hardware */
+	err = si5341_wait_device_ready(client);
+	if (err)
+		return err;
+
 	for (i = 0; i < SI5341_NUM_INPUTS; ++i) {
 		input = devm_clk_get(&client->dev, si5341_input_clock_names[i]);
 		if (IS_ERR(input)) {
-- 
2.27.0

[PATCH v3 3/9] clk: si5341: Avoid divide errors due to bogus register contents

[Robert Hancock]

If the Si5341 is being initially programmed and has no stored NVM
configuration, some of the register contents may contain unexpected
values, such as zeros, which could cause divide by zero errors during
driver initialization. Trap errors caused by zero registers or zero clock
rates which could result in divide errors later in the code.

Fixes: 3044a860fd ("clk: Add Si5341/Si5340 driver")
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 drivers/clk/clk-si5341.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c
index b8a960e927bc..ac1ccec2b681 100644
--- a/drivers/clk/clk-si5341.c
+++ b/drivers/clk/clk-si5341.c
@@ -624,6 +624,9 @@ static unsigned long si5341_synth_clk_recalc_rate(struct clk_hw *hw,
 			SI5341_SYNTH_N_NUM(synth->index), &n_num, &n_den);
 	if (err < 0)
 		return err;
+	/* Check for bogus/uninitialized settings */
+	if (!n_num || !n_den)
+		return 0;
 
 	/*
 	 * n_num and n_den are shifted left as much as possible, so to prevent
@@ -807,6 +810,9 @@ static long si5341_output_clk_round_rate(struct clk_hw *hw, unsigned long rate,
 {
 	unsigned long r;
 
+	if (!rate)
+		return 0;
+
 	r = *parent_rate >> 1;
 
 	/* If rate is an even divisor, no changes to parent required */
@@ -835,11 +841,16 @@ static int si5341_output_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 		unsigned long parent_rate)
 {
 	struct clk_si5341_output *output = to_clk_si5341_output(hw);
-	/* Frequency divider is (r_div + 1) * 2 */
-	u32 r_div = (parent_rate / rate) >> 1;
+	u32 r_div;
 	int err;
 	u8 r[3];
 
+	if (!rate)
+		return -EINVAL;
+
+	/* Frequency divider is (r_div + 1) * 2 */
+	r_div = (parent_rate / rate) >> 1;
+
 	if (r_div <= 1)
 		r_div = 0;
 	else if (r_div >= BIT(24))
-- 
2.27.0

[PATCH v3 4/9] clk: si5341: Check for input clock presence and PLL lock on startup

[Robert Hancock]

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 <robert.hancock@calian.com>
---
 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

[PATCH v3 5/9] clk: si5341: Update initialization magic

[Robert Hancock]

Update the default register settings to include the VCO_RESET_CALCODE
settings (set by the SiLabs ClockBuilder software but not described in
the datasheet). Also update part of the initialization sequence to match
ClockBuilder and the datasheet.

Fixes: 3044a860fd ("clk: Add Si5341/Si5340 driver")
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 drivers/clk/clk-si5341.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c
index da40b90c2aa8..eb22f4fdbc6b 100644
--- a/drivers/clk/clk-si5341.c
+++ b/drivers/clk/clk-si5341.c
@@ -350,6 +350,8 @@ static const struct si5341_reg_default si5341_reg_defaults[] = {
 	{ 0x094A, 0x00 }, /* INx_TO_PFD_EN (disabled) */
 	{ 0x0A02, 0x00 }, /* Not in datasheet */
 	{ 0x0B44, 0x0F }, /* PDIV_ENB (datasheet does not mention what it is) */
+	{ 0x0B57, 0x10 }, /* VCO_RESET_CALCODE (not described in datasheet) */
+	{ 0x0B58, 0x05 }, /* VCO_RESET_CALCODE (not described in datasheet) */
 };
 
 /* Read and interpret a 44-bit followed by a 32-bit value in the regmap */
@@ -1104,7 +1106,7 @@ static const struct si5341_reg_default si5341_preamble[] = {
 	{ 0x0B25, 0x00 },
 	{ 0x0502, 0x01 },
 	{ 0x0505, 0x03 },
-	{ 0x0957, 0x1F },
+	{ 0x0957, 0x17 },
 	{ 0x0B4E, 0x1A },
 };
 
-- 
2.27.0

[PATCH v3 6/9] clk: si5341: Allow different output VDD_SEL values

[Robert Hancock]

The driver was not previously programming the VDD_SEL values for each
output to indicate what external VDDO voltage was used for each. Add
ability to specify a regulator supplying the VDDO pin for each output of
the device. The voltage of the regulator is used to automatically set the
VDD_SEL value appropriately. If no regulator is specified and the chip is
being reconfigured, assume 2.5V which appears to be the chip default.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 drivers/clk/clk-si5341.c | 136 +++++++++++++++++++++++++++++++--------
 1 file changed, 110 insertions(+), 26 deletions(-)

diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c
index eb22f4fdbc6b..28ac7085f362 100644
--- a/drivers/clk/clk-si5341.c
+++ b/drivers/clk/clk-si5341.c
@@ -19,6 +19,7 @@
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <asm/unaligned.h>
 
@@ -59,6 +60,7 @@ struct clk_si5341_synth {
 struct clk_si5341_output {
 	struct clk_hw hw;
 	struct clk_si5341 *data;
+	struct regulator *vddo_reg;
 	u8 index;
 };
 #define to_clk_si5341_output(_hw) \
@@ -84,6 +86,7 @@ struct clk_si5341 {
 struct clk_si5341_output_config {
 	u8 out_format_drv_bits;
 	u8 out_cm_ampl_bits;
+	u8 vdd_sel_bits;
 	bool synth_master;
 	bool always_on;
 };
@@ -136,6 +139,8 @@ struct clk_si5341_output_config {
 #define SI5341_OUT_R_REG(output)	\
 			((output)->data->reg_rdiv_offset[(output)->index])
 
+#define SI5341_OUT_MUX_VDD_SEL_MASK 0x38
+
 /* Synthesize N divider */
 #define SI5341_SYNTH_N_NUM(x)	(0x0302 + ((x) * 11))
 #define SI5341_SYNTH_N_DEN(x)	(0x0308 + ((x) * 11))
@@ -1248,11 +1253,11 @@ static const struct regmap_config si5341_regmap_config = {
 	.volatile_table = &si5341_regmap_volatile,
 };
 
-static int si5341_dt_parse_dt(struct i2c_client *client,
-	struct clk_si5341_output_config *config)
+static int si5341_dt_parse_dt(struct clk_si5341 *data,
+			      struct clk_si5341_output_config *config)
 {
 	struct device_node *child;
-	struct device_node *np = client->dev.of_node;
+	struct device_node *np = data->i2c_client->dev.of_node;
 	u32 num;
 	u32 val;
 
@@ -1261,13 +1266,13 @@ static int si5341_dt_parse_dt(struct i2c_client *client,
 
 	for_each_child_of_node(np, child) {
 		if (of_property_read_u32(child, "reg", &num)) {
-			dev_err(&client->dev, "missing reg property of %s\n",
+			dev_err(&data->i2c_client->dev, "missing reg property of %s\n",
 				child->name);
 			goto put_child;
 		}
 
 		if (num >= SI5341_MAX_NUM_OUTPUTS) {
-			dev_err(&client->dev, "invalid clkout %d\n", num);
+			dev_err(&data->i2c_client->dev, "invalid clkout %d\n", num);
 			goto put_child;
 		}
 
@@ -1286,7 +1291,7 @@ static int si5341_dt_parse_dt(struct i2c_client *client,
 				config[num].out_format_drv_bits |= 0xc0;
 				break;
 			default:
-				dev_err(&client->dev,
+				dev_err(&data->i2c_client->dev,
 					"invalid silabs,format %u for %u\n",
 					val, num);
 				goto put_child;
@@ -1299,7 +1304,7 @@ static int si5341_dt_parse_dt(struct i2c_client *client,
 
 		if (!of_property_read_u32(child, "silabs,common-mode", &val)) {
 			if (val > 0xf) {
-				dev_err(&client->dev,
+				dev_err(&data->i2c_client->dev,
 					"invalid silabs,common-mode %u\n",
 					val);
 				goto put_child;
@@ -1310,7 +1315,7 @@ static int si5341_dt_parse_dt(struct i2c_client *client,
 
 		if (!of_property_read_u32(child, "silabs,amplitude", &val)) {
 			if (val > 0xf) {
-				dev_err(&client->dev,
+				dev_err(&data->i2c_client->dev,
 					"invalid silabs,amplitude %u\n",
 					val);
 				goto put_child;
@@ -1327,6 +1332,34 @@ static int si5341_dt_parse_dt(struct i2c_client *client,
 
 		config[num].always_on =
 			of_property_read_bool(child, "always-on");
+
+		config[num].vdd_sel_bits = 0x08;
+		if (data->clk[num].vddo_reg) {
+			int vdd = regulator_get_voltage(data->clk[num].vddo_reg);
+
+			switch (vdd) {
+			case 3300000:
+				config[num].vdd_sel_bits |= 0 << 4;
+				break;
+			case 1800000:
+				config[num].vdd_sel_bits |= 1 << 4;
+				break;
+			case 2500000:
+				config[num].vdd_sel_bits |= 2 << 4;
+				break;
+			default:
+				dev_err(&data->i2c_client->dev,
+					"unsupported vddo voltage %d for %s\n",
+					vdd, child->name);
+				goto put_child;
+			}
+		} else {
+			/* chip seems to default to 2.5V when not set */
+			dev_warn(&data->i2c_client->dev,
+				"no regulator set, defaulting vdd_sel to 2.5V for %s\n",
+				child->name);
+			config[num].vdd_sel_bits |= 2 << 4;
+		}
 	}
 
 	return 0;
@@ -1452,9 +1485,33 @@ static int si5341_probe(struct i2c_client *client,
 		}
 	}
 
-	err = si5341_dt_parse_dt(client, config);
+	for (i = 0; i < SI5341_MAX_NUM_OUTPUTS; ++i) {
+		char reg_name[10];
+
+		snprintf(reg_name, sizeof(reg_name), "vddo%d", i);
+		data->clk[i].vddo_reg = devm_regulator_get_optional(
+			&client->dev, reg_name);
+		if (IS_ERR(data->clk[i].vddo_reg)) {
+			err = PTR_ERR(data->clk[i].vddo_reg);
+			data->clk[i].vddo_reg = NULL;
+			if (err == -ENODEV)
+				continue;
+			goto cleanup;
+		} else {
+			err = regulator_enable(data->clk[i].vddo_reg);
+			if (err) {
+				dev_err(&client->dev,
+					"failed to enable %s regulator: %d\n",
+					reg_name, err);
+				data->clk[i].vddo_reg = NULL;
+				goto cleanup;
+			}
+		}
+	}
+
+	err = si5341_dt_parse_dt(data, config);
 	if (err)
-		return err;
+		goto cleanup;
 
 	if (of_property_read_string(client->dev.of_node, "clock-output-names",
 			&init.name))
@@ -1462,21 +1519,23 @@ static int si5341_probe(struct i2c_client *client,
 	root_clock_name = init.name;
 
 	data->regmap = devm_regmap_init_i2c(client, &si5341_regmap_config);
-	if (IS_ERR(data->regmap))
-		return PTR_ERR(data->regmap);
+	if (IS_ERR(data->regmap)) {
+		err = PTR_ERR(data->regmap);
+		goto cleanup;
+	}
 
 	i2c_set_clientdata(client, data);
 
 	err = si5341_probe_chip_id(data);
 	if (err < 0)
-		return err;
+		goto cleanup;
 
 	if (of_property_read_bool(client->dev.of_node, "silabs,reprogram")) {
 		initialization_required = true;
 	} else {
 		err = si5341_is_programmed_already(data);
 		if (err < 0)
-			return err;
+			goto cleanup;
 
 		initialization_required = !err;
 	}
@@ -1485,11 +1544,11 @@ static int si5341_probe(struct i2c_client *client,
 		/* Populate the regmap cache in preparation for "cache only" */
 		err = si5341_read_settings(data);
 		if (err < 0)
-			return err;
+			goto cleanup;
 
 		err = si5341_send_preamble(data);
 		if (err < 0)
-			return err;
+			goto cleanup;
 
 		/*
 		 * We intend to send all 'final' register values in a single
@@ -1502,19 +1561,19 @@ static int si5341_probe(struct i2c_client *client,
 		err = si5341_write_multiple(data, si5341_reg_defaults,
 					ARRAY_SIZE(si5341_reg_defaults));
 		if (err < 0)
-			return err;
+			goto cleanup;
 	}
 
 	/* Input must be up and running at this point */
 	err = si5341_clk_select_active_input(data);
 	if (err < 0)
-		return err;
+		goto cleanup;
 
 	if (initialization_required) {
 		/* PLL configuration is required */
 		err = si5341_initialize_pll(data);
 		if (err < 0)
-			return err;
+			goto cleanup;
 	}
 
 	/* Register the PLL */
@@ -1527,7 +1586,7 @@ static int si5341_probe(struct i2c_client *client,
 	err = devm_clk_hw_register(&client->dev, &data->hw);
 	if (err) {
 		dev_err(&client->dev, "clock registration failed\n");
-		return err;
+		goto cleanup;
 	}
 
 	init.num_parents = 1;
@@ -1564,13 +1623,17 @@ static int si5341_probe(struct i2c_client *client,
 			regmap_write(data->regmap,
 				SI5341_OUT_CM(&data->clk[i]),
 				config[i].out_cm_ampl_bits);
+			regmap_update_bits(data->regmap,
+				SI5341_OUT_MUX_SEL(&data->clk[i]),
+				SI5341_OUT_MUX_VDD_SEL_MASK,
+				config[i].vdd_sel_bits);
 		}
 		err = devm_clk_hw_register(&client->dev, &data->clk[i].hw);
 		kfree(init.name); /* clock framework made a copy of the name */
 		if (err) {
 			dev_err(&client->dev,
 				"output %u registration failed\n", i);
-			return err;
+			goto cleanup;
 		}
 		if (config[i].always_on)
 			clk_prepare(data->clk[i].hw.clk);
@@ -1580,7 +1643,7 @@ static int si5341_probe(struct i2c_client *client,
 			data);
 	if (err) {
 		dev_err(&client->dev, "unable to add clk provider\n");
-		return err;
+		goto cleanup;
 	}
 
 	if (initialization_required) {
@@ -1588,11 +1651,11 @@ static int si5341_probe(struct i2c_client *client,
 		regcache_cache_only(data->regmap, false);
 		err = regcache_sync(data->regmap);
 		if (err < 0)
-			return err;
+			goto cleanup;
 
 		err = si5341_finalize_defaults(data);
 		if (err < 0)
-			return err;
+			goto cleanup;
 	}
 
 	/* wait for device to report input clock present and PLL lock */
@@ -1601,14 +1664,14 @@ static int si5341_probe(struct i2c_client *client,
 	       10000, 250000);
 	if (err) {
 		dev_err(&client->dev, "Error waiting for input clock or PLL lock\n");
-		return err;
+		goto cleanup;
 	}
 
 	/* 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;
+		goto cleanup;
 	}
 
 	/* Free the names, clk framework makes copies */
@@ -1616,6 +1679,26 @@ static int si5341_probe(struct i2c_client *client,
 		 devm_kfree(&client->dev, (void *)synth_clock_names[i]);
 
 	return 0;
+
+cleanup:
+	for (i = 0; i < SI5341_MAX_NUM_OUTPUTS; ++i) {
+		if (data->clk[i].vddo_reg)
+			regulator_disable(data->clk[i].vddo_reg);
+	}
+	return err;
+}
+
+static int si5341_remove(struct i2c_client *client)
+{
+	struct clk_si5341 *data = i2c_get_clientdata(client);
+	int i;
+
+	for (i = 0; i < SI5341_MAX_NUM_OUTPUTS; ++i) {
+		if (data->clk[i].vddo_reg)
+			regulator_disable(data->clk[i].vddo_reg);
+	}
+
+	return 0;
 }
 
 static const struct i2c_device_id si5341_id[] = {
@@ -1644,6 +1727,7 @@ static struct i2c_driver si5341_driver = {
 		.of_match_table = clk_si5341_of_match,
 	},
 	.probe		= si5341_probe,
+	.remove		= si5341_remove,
 	.id_table	= si5341_id,
 };
 module_i2c_driver(si5341_driver);
-- 
2.27.0

[PATCH v3 7/9] clk: si5341: Add silabs,xaxb-ext-clk property

[Robert Hancock]

Add a property to allow specifying that the device XA/XB pins are used for
an external clock input rather than for a clock crystal.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 drivers/clk/clk-si5341.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c
index 28ac7085f362..c5ab4a5ae6a5 100644
--- a/drivers/clk/clk-si5341.c
+++ b/drivers/clk/clk-si5341.c
@@ -80,6 +80,7 @@ struct clk_si5341 {
 	u8 num_outputs;
 	u8 num_synth;
 	u16 chip_id;
+	bool xaxb_ext_clk;
 };
 #define to_clk_si5341(_hw)	container_of(_hw, struct clk_si5341, hw)
 
@@ -529,9 +530,11 @@ static int si5341_clk_reparent(struct clk_si5341 *data, u8 index)
 		if (err < 0)
 			return err;
 
-		/* Power up XTAL oscillator and buffer */
+		/* Power up XTAL oscillator and buffer, select clock mode */
 		err = regmap_update_bits(data->regmap, SI5341_XAXB_CFG,
-				SI5341_XAXB_CFG_PDNB, SI5341_XAXB_CFG_PDNB);
+				SI5341_XAXB_CFG_PDNB | SI5341_XAXB_CFG_EXTCLK_EN,
+				SI5341_XAXB_CFG_PDNB | (data->xaxb_ext_clk ?
+					SI5341_XAXB_CFG_EXTCLK_EN : 0));
 		if (err < 0)
 			return err;
 	}
@@ -1539,6 +1542,8 @@ static int si5341_probe(struct i2c_client *client,
 
 		initialization_required = !err;
 	}
+	data->xaxb_ext_clk = of_property_read_bool(client->dev.of_node,
+						   "silabs,xaxb-ext-clk");
 
 	if (initialization_required) {
 		/* Populate the regmap cache in preparation for "cache only" */
-- 
2.27.0

[PATCH v3 8/9] clk: si5341: Add silabs,iovdd-33 property

[Robert Hancock]

Add a property to allow specifying that the external I2C IO pins are using
3.3V voltage thresholds rather than 1.8V.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 drivers/clk/clk-si5341.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c
index c5ab4a5ae6a5..d4aa67a4dc66 100644
--- a/drivers/clk/clk-si5341.c
+++ b/drivers/clk/clk-si5341.c
@@ -81,6 +81,7 @@ struct clk_si5341 {
 	u8 num_synth;
 	u16 chip_id;
 	bool xaxb_ext_clk;
+	bool iovdd_33;
 };
 #define to_clk_si5341(_hw)	container_of(_hw, struct clk_si5341, hw)
 
@@ -103,6 +104,7 @@ struct clk_si5341_output_config {
 #define SI5341_IN_SEL		0x0021
 #define SI5341_DEVICE_READY	0x00FE
 #define SI5341_XAXB_CFG		0x090E
+#define SI5341_IO_VDD_SEL	0x0943
 #define SI5341_IN_EN		0x0949
 #define SI5341_INX_TO_PFD_EN	0x094A
 
@@ -351,7 +353,6 @@ static const struct si5341_reg_default si5341_reg_defaults[] = {
 	{ 0x0804, 0x00 }, /* Not in datasheet */
 	{ 0x090E, 0x02 }, /* XAXB_EXTCLK_EN=0 XAXB_PDNB=1 (use XTAL) */
 	{ 0x091C, 0x04 }, /* ZDM_EN=4 (Normal mode) */
-	{ 0x0943, 0x00 }, /* IO_VDD_SEL=0 (0=1v8, use 1=3v3) */
 	{ 0x0949, 0x00 }, /* IN_EN (disable input clocks) */
 	{ 0x094A, 0x00 }, /* INx_TO_PFD_EN (disabled) */
 	{ 0x0A02, 0x00 }, /* Not in datasheet */
@@ -1160,6 +1161,11 @@ static int si5341_finalize_defaults(struct clk_si5341 *data)
 	int res;
 	u32 revision;
 
+	res = regmap_write(data->regmap, SI5341_IO_VDD_SEL,
+			   data->iovdd_33 ? 1 : 0);
+	if (res < 0)
+		return res;
+
 	res = regmap_read(data->regmap, SI5341_DEVICE_REV, &revision);
 	if (res < 0)
 		return res;
@@ -1544,6 +1550,8 @@ static int si5341_probe(struct i2c_client *client,
 	}
 	data->xaxb_ext_clk = of_property_read_bool(client->dev.of_node,
 						   "silabs,xaxb-ext-clk");
+	data->iovdd_33 = of_property_read_bool(client->dev.of_node,
+					       "silabs,iovdd-33");
 
 	if (initialization_required) {
 		/* Populate the regmap cache in preparation for "cache only" */
-- 
2.27.0

[PATCH v3 9/9] clk: si5341: Add sysfs properties to allow checking/resetting device faults

[Robert Hancock]

Add sysfs property files to allow viewing the current and latched states of
the input present and PLL lock bits, and allow resetting the latched fault
state. This allows manual checks or automated userspace polling for faults
occurring after initialization.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 drivers/clk/clk-si5341.c | 96 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)

diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c
index d4aa67a4dc66..57ae183982d8 100644
--- a/drivers/clk/clk-si5341.c
+++ b/drivers/clk/clk-si5341.c
@@ -1457,6 +1457,94 @@ static int si5341_clk_select_active_input(struct clk_si5341 *data)
 	return res;
 }
 
+static ssize_t input_present_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	struct clk_si5341 *data = dev_get_drvdata(dev);
+	u32 status;
+	int res = regmap_read(data->regmap, SI5341_STATUS, &status);
+
+	if (res < 0)
+		return res;
+	res = !(status & SI5341_STATUS_LOSREF);
+	return snprintf(buf, PAGE_SIZE, "%d\n", res);
+}
+static DEVICE_ATTR_RO(input_present);
+
+static ssize_t input_present_sticky_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct clk_si5341 *data = dev_get_drvdata(dev);
+	u32 status;
+	int res = regmap_read(data->regmap, SI5341_STATUS_STICKY, &status);
+
+	if (res < 0)
+		return res;
+	res = !(status & SI5341_STATUS_LOSREF);
+	return snprintf(buf, PAGE_SIZE, "%d\n", res);
+}
+static DEVICE_ATTR_RO(input_present_sticky);
+
+static ssize_t pll_locked_show(struct device *dev,
+			       struct device_attribute *attr,
+			       char *buf)
+{
+	struct clk_si5341 *data = dev_get_drvdata(dev);
+	u32 status;
+	int res = regmap_read(data->regmap, SI5341_STATUS, &status);
+
+	if (res < 0)
+		return res;
+	res = !(status & SI5341_STATUS_LOL);
+	return snprintf(buf, PAGE_SIZE, "%d\n", res);
+}
+static DEVICE_ATTR_RO(pll_locked);
+
+static ssize_t pll_locked_sticky_show(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	struct clk_si5341 *data = dev_get_drvdata(dev);
+	u32 status;
+	int res = regmap_read(data->regmap, SI5341_STATUS_STICKY, &status);
+
+	if (res < 0)
+		return res;
+	res = !(status & SI5341_STATUS_LOL);
+	return snprintf(buf, PAGE_SIZE, "%d\n", res);
+}
+static DEVICE_ATTR_RO(pll_locked_sticky);
+
+static ssize_t clear_sticky_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct clk_si5341 *data = dev_get_drvdata(dev);
+	long val;
+
+	if (kstrtol(buf, 10, &val))
+		return -EINVAL;
+	if (val) {
+		int res = regmap_write(data->regmap, SI5341_STATUS_STICKY, 0);
+
+		if (res < 0)
+			return res;
+	}
+	return count;
+}
+static DEVICE_ATTR_WO(clear_sticky);
+
+static const struct attribute *si5341_attributes[] = {
+	&dev_attr_input_present.attr,
+	&dev_attr_input_present_sticky.attr,
+	&dev_attr_pll_locked.attr,
+	&dev_attr_pll_locked_sticky.attr,
+	&dev_attr_clear_sticky.attr,
+	NULL
+};
+
 static int si5341_probe(struct i2c_client *client,
 		const struct i2c_device_id *id)
 {
@@ -1687,6 +1775,12 @@ static int si5341_probe(struct i2c_client *client,
 		goto cleanup;
 	}
 
+	err = sysfs_create_files(&client->dev.kobj, si5341_attributes);
+	if (err) {
+		dev_err(&client->dev, "unable to create sysfs files\n");
+		goto cleanup;
+	}
+
 	/* Free the names, clk framework makes copies */
 	for (i = 0; i < data->num_synth; ++i)
 		 devm_kfree(&client->dev, (void *)synth_clock_names[i]);
@@ -1706,6 +1800,8 @@ static int si5341_remove(struct i2c_client *client)
 	struct clk_si5341 *data = i2c_get_clientdata(client);
 	int i;
 
+	sysfs_remove_files(&client->dev.kobj, si5341_attributes);
+
 	for (i = 0; i < SI5341_MAX_NUM_OUTPUTS; ++i) {
 		if (data->clk[i].vddo_reg)
 			regulator_disable(data->clk[i].vddo_reg);
-- 
2.27.0

Re: [PATCH v3 1/9] dt-bindings: clock: clk-si5341: Add new attributes

[Rob Herring]

On Thu, 25 Mar 2021 13:26:35 -0600, Robert Hancock wrote:
> Add new silabs,xaxb-ext-clk and silabs,iovdd-33 properties.
> 
> Changed vdd-supply on top-level node to optional since it is not actually
> used by the driver.
> 
> Removed vdd-supply from output sub-nodes, as it was not supported by the
> driver and it is not easily possible to support this in that location with
> the kernel regulator infrastructure. Changed to have vddoX-supply
> attributes for each output on the top-level device node.
> 
> Signed-off-by: Robert Hancock <robert.hancock@calian.com>
> ---
>  .../devicetree/bindings/clock/silabs,si5341.txt  | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v3 0/9] Si5341 driver updates

[Robert Hancock]

On Thu, 2021-03-25 at 13:26 -0600, Robert Hancock wrote:
> Various fixes and enhancements to the Si5341 driver.
> 
> Changed since v2:
> -changed regulator reference for output supply from vdd to vddo to match
> data sheet
> 
> Changed since v1:
> -wait up to 300ms for DEVICE_READY
> -use regmap_read_poll_timeout rather than fixed wait when waiting for PLL
> lock and input presence
> -make si5341_remove static
> 
> Robert Hancock (9):
>   dt-bindings: clock: clk-si5341: Add new attributes
>   clk: si5341: Wait for DEVICE_READY on startup
>   clk: si5341: Avoid divide errors due to bogus register contents
>   clk: si5341: Check for input clock presence and PLL lock on startup
>   clk: si5341: Update initialization magic
>   clk: si5341: Allow different output VDD_SEL values
>   clk: si5341: Add silabs,xaxb-ext-clk property
>   clk: si5341: Add silabs,iovdd-33 property
>   clk: si5341: Add sysfs properties to allow checking/resetting device
>     faults
> 
>  .../bindings/clock/silabs,si5341.txt          |  16 +-
>  drivers/clk/clk-si5341.c                      | 324 ++++++++++++++++--
>  2 files changed, 304 insertions(+), 36 deletions(-)
> 

Ping.. any feedback on this patch set? (Aside from one ack on patch 1..)

-- 
Robert Hancock
Senior Hardware Designer, Calian Advanced Technologies
www.calian.com

Re: [PATCH v3 1/9] dt-bindings: clock: clk-si5341: Add new attributes

[Stephen Boyd]

Quoting Robert Hancock (2021-03-25 12:26:35)
> Add new silabs,xaxb-ext-clk and silabs,iovdd-33 properties.
> 
> Changed vdd-supply on top-level node to optional since it is not actually
> used by the driver.
> 
> Removed vdd-supply from output sub-nodes, as it was not supported by the
> driver and it is not easily possible to support this in that location with
> the kernel regulator infrastructure. Changed to have vddoX-supply
> attributes for each output on the top-level device node.
> 
> Signed-off-by: Robert Hancock <robert.hancock@calian.com>
> ---

Applied to clk-next

Re: [PATCH v3 2/9] clk: si5341: Wait for DEVICE_READY on startup

[Stephen Boyd]

Quoting Robert Hancock (2021-03-25 12:26:36)
> The Si5341 datasheet warns that before accessing any other registers,
> including the PAGE register, we need to wait for the DEVICE_READY register
> to indicate the device is ready, or the process of the device loading its
> state from NVM can be corrupted. Wait for DEVICE_READY on startup before
> continuing initialization. This is done using a raw I2C register read
> prior to setting up regmap to avoid any potential unwanted automatic PAGE
> register accesses from regmap at this stage.
> 
> Fixes: 3044a860fd ("clk: Add Si5341/Si5340 driver")
> Signed-off-by: Robert Hancock <robert.hancock@calian.com>
> ---

Applied to clk-next

Re: [PATCH v3 3/9] clk: si5341: Avoid divide errors due to bogus register contents

[Stephen Boyd]

Quoting Robert Hancock (2021-03-25 12:26:37)
> If the Si5341 is being initially programmed and has no stored NVM
> configuration, some of the register contents may contain unexpected
> values, such as zeros, which could cause divide by zero errors during
> driver initialization. Trap errors caused by zero registers or zero clock
> rates which could result in divide errors later in the code.
> 
> Fixes: 3044a860fd ("clk: Add Si5341/Si5340 driver")
> Signed-off-by: Robert Hancock <robert.hancock@calian.com>
> ---

Applied to clk-next

Re: [PATCH v3 4/9] clk: si5341: Check for input clock presence and PLL lock on startup

[Stephen Boyd]

Quoting Robert Hancock (2021-03-25 12:26:38)
> 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 <robert.hancock@calian.com>
> ---

Applied to clk-next

Re: [PATCH v3 5/9] clk: si5341: Update initialization magic

[Stephen Boyd]

Quoting Robert Hancock (2021-03-25 12:26:39)
> Update the default register settings to include the VCO_RESET_CALCODE
> settings (set by the SiLabs ClockBuilder software but not described in
> the datasheet). Also update part of the initialization sequence to match
> ClockBuilder and the datasheet.
> 
> Fixes: 3044a860fd ("clk: Add Si5341/Si5340 driver")
> Signed-off-by: Robert Hancock <robert.hancock@calian.com>
> ---

Applied to clk-next

Re: [PATCH v3 6/9] clk: si5341: Allow different output VDD_SEL values

[Stephen Boyd]

Quoting Robert Hancock (2021-03-25 12:26:40)
> The driver was not previously programming the VDD_SEL values for each
> output to indicate what external VDDO voltage was used for each. Add
> ability to specify a regulator supplying the VDDO pin for each output of
> the device. The voltage of the regulator is used to automatically set the
> VDD_SEL value appropriately. If no regulator is specified and the chip is
> being reconfigured, assume 2.5V which appears to be the chip default.
> 
> Signed-off-by: Robert Hancock <robert.hancock@calian.com>
> ---

Applied to clk-next

Re: [PATCH v3 7/9] clk: si5341: Add silabs,xaxb-ext-clk property

[Stephen Boyd]

Quoting Robert Hancock (2021-03-25 12:26:41)
> Add a property to allow specifying that the device XA/XB pins are used for
> an external clock input rather than for a clock crystal.
> 
> Signed-off-by: Robert Hancock <robert.hancock@calian.com>
> ---

Applied to clk-next

Re: [PATCH v3 8/9] clk: si5341: Add silabs,iovdd-33 property

[Stephen Boyd]

Quoting Robert Hancock (2021-03-25 12:26:42)
> Add a property to allow specifying that the external I2C IO pins are using
> 3.3V voltage thresholds rather than 1.8V.
> 
> Signed-off-by: Robert Hancock <robert.hancock@calian.com>
> ---

Applied to clk-next

Re: [PATCH v3 9/9] clk: si5341: Add sysfs properties to allow checking/resetting device faults

[Stephen Boyd]

Quoting Robert Hancock (2021-03-25 12:26:43)
> Add sysfs property files to allow viewing the current and latched states of
> the input present and PLL lock bits, and allow resetting the latched fault
> state. This allows manual checks or automated userspace polling for faults
> occurring after initialization.
> 
> Signed-off-by: Robert Hancock <robert.hancock@calian.com>
> ---

Applied to clk-next