[PATCH net-next v2 4/5] dpll: zl3073x: Add support to adjust phase

[Ivan Vecera <ivecera@redhat.com>]

Add support to get/set phase adjustment for both input and output pins.
The phase adjustment is implemented using reference and output phase
offset compensation registers. For input pins the adjustment value can
be arbitrary number but for outputs the value has to be a multiple
of half synthesizer clock cycles.

Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Tested-by: Prathosh Satish <prathosh.satish@microchip.com>
Co-developed-by: Prathosh Satish <Prathosh.Satish@microchip.com>
Signed-off-by: Prathosh Satish <Prathosh.Satish@microchip.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
v2:
* added check for zero synth frequency to avoid division by zero
---
 drivers/dpll/zl3073x/dpll.c | 191 ++++++++++++++++++++++++++++++++++++
 drivers/dpll/zl3073x/regs.h |   3 +
 2 files changed, 194 insertions(+)

diff --git a/drivers/dpll/zl3073x/dpll.c b/drivers/dpll/zl3073x/dpll.c
index 11a7c4a58e257..a63a3434da744 100644
--- a/drivers/dpll/zl3073x/dpll.c
+++ b/drivers/dpll/zl3073x/dpll.c
@@ -574,6 +574,85 @@ zl3073x_dpll_input_pin_phase_offset_get(const struct dpll_pin *dpll_pin,
 	return rc;
 }
 
+static int
+zl3073x_dpll_input_pin_phase_adjust_get(const struct dpll_pin *dpll_pin,
+					void *pin_priv,
+					const struct dpll_device *dpll,
+					void *dpll_priv,
+					s32 *phase_adjust,
+					struct netlink_ext_ack *extack)
+{
+	struct zl3073x_dpll *zldpll = dpll_priv;
+	struct zl3073x_dev *zldev = zldpll->dev;
+	struct zl3073x_dpll_pin *pin = pin_priv;
+	s64 phase_comp;
+	u8 ref;
+	int rc;
+
+	guard(mutex)(&zldev->multiop_lock);
+
+	/* Read reference configuration */
+	ref = zl3073x_input_pin_ref_get(pin->id);
+	rc = zl3073x_mb_op(zldev, ZL_REG_REF_MB_SEM, ZL_REF_MB_SEM_RD,
+			   ZL_REG_REF_MB_MASK, BIT(ref));
+	if (rc)
+		return rc;
+
+	/* Read current phase offset compensation */
+	rc = zl3073x_read_u48(zldev, ZL_REG_REF_PHASE_OFFSET_COMP, &phase_comp);
+	if (rc)
+		return rc;
+
+	/* Perform sign extension for 48bit signed value */
+	phase_comp = sign_extend64(phase_comp, 47);
+
+	/* Reverse two's complement negation applied during set and convert
+	 * to 32bit signed int
+	 */
+	*phase_adjust = (s32)-phase_comp;
+
+	return rc;
+}
+
+static int
+zl3073x_dpll_input_pin_phase_adjust_set(const struct dpll_pin *dpll_pin,
+					void *pin_priv,
+					const struct dpll_device *dpll,
+					void *dpll_priv,
+					s32 phase_adjust,
+					struct netlink_ext_ack *extack)
+{
+	struct zl3073x_dpll *zldpll = dpll_priv;
+	struct zl3073x_dev *zldev = zldpll->dev;
+	struct zl3073x_dpll_pin *pin = pin_priv;
+	s64 phase_comp;
+	u8 ref;
+	int rc;
+
+	/* The value in the register is stored as two's complement negation
+	 * of requested value.
+	 */
+	phase_comp = -phase_adjust;
+
+	guard(mutex)(&zldev->multiop_lock);
+
+	/* Read reference configuration */
+	ref = zl3073x_input_pin_ref_get(pin->id);
+	rc = zl3073x_mb_op(zldev, ZL_REG_REF_MB_SEM, ZL_REF_MB_SEM_RD,
+			   ZL_REG_REF_MB_MASK, BIT(ref));
+	if (rc)
+		return rc;
+
+	/* Write the requested value into the compensation register */
+	rc = zl3073x_write_u48(zldev, ZL_REG_REF_PHASE_OFFSET_COMP, phase_comp);
+	if (rc)
+		return rc;
+
+	/* Commit reference configuration */
+	return zl3073x_mb_op(zldev, ZL_REG_REF_MB_SEM, ZL_REF_MB_SEM_WR,
+			     ZL_REG_REF_MB_MASK, BIT(ref));
+}
+
 /**
  * zl3073x_dpll_ref_prio_get - get priority for given input pin
  * @pin: pointer to pin
@@ -1284,6 +1363,114 @@ zl3073x_dpll_output_pin_frequency_set(const struct dpll_pin *dpll_pin,
 			     ZL_REG_OUTPUT_MB_MASK, BIT(out));
 }
 
+static int
+zl3073x_dpll_output_pin_phase_adjust_get(const struct dpll_pin *dpll_pin,
+					 void *pin_priv,
+					 const struct dpll_device *dpll,
+					 void *dpll_priv,
+					 s32 *phase_adjust,
+					 struct netlink_ext_ack *extack)
+{
+	struct zl3073x_dpll *zldpll = dpll_priv;
+	struct zl3073x_dev *zldev = zldpll->dev;
+	struct zl3073x_dpll_pin *pin = pin_priv;
+	u32 synth_freq;
+	s32 phase_comp;
+	u8 out, synth;
+	int rc;
+
+	out = zl3073x_output_pin_out_get(pin->id);
+	synth = zl3073x_out_synth_get(zldev, out);
+	synth_freq = zl3073x_synth_freq_get(zldev, synth);
+
+	/* Check synth freq for zero */
+	if (!synth_freq) {
+		dev_err(zldev->dev, "Got zero synth frequency for output %u\n",
+			out);
+		return -EINVAL;
+	}
+
+	guard(mutex)(&zldev->multiop_lock);
+
+	/* Read output configuration */
+	rc = zl3073x_mb_op(zldev, ZL_REG_OUTPUT_MB_SEM, ZL_OUTPUT_MB_SEM_RD,
+			   ZL_REG_OUTPUT_MB_MASK, BIT(out));
+	if (rc)
+		return rc;
+
+	/* Read current output phase compensation */
+	rc = zl3073x_read_u32(zldev, ZL_REG_OUTPUT_PHASE_COMP, &phase_comp);
+	if (rc)
+		return rc;
+
+	/* Value in register is expressed in half synth clock cycles */
+	phase_comp *= (int)div_u64(PSEC_PER_SEC, 2 * synth_freq);
+
+	/* Reverse two's complement negation applied during 'set' */
+	*phase_adjust = -phase_comp;
+
+	return rc;
+}
+
+static int
+zl3073x_dpll_output_pin_phase_adjust_set(const struct dpll_pin *dpll_pin,
+					 void *pin_priv,
+					 const struct dpll_device *dpll,
+					 void *dpll_priv,
+					 s32 phase_adjust,
+					 struct netlink_ext_ack *extack)
+{
+	struct zl3073x_dpll *zldpll = dpll_priv;
+	struct zl3073x_dev *zldev = zldpll->dev;
+	struct zl3073x_dpll_pin *pin = pin_priv;
+	int half_synth_cycle;
+	u32 synth_freq;
+	u8 out, synth;
+	int rc;
+
+	/* Get attached synth */
+	out = zl3073x_output_pin_out_get(pin->id);
+	synth = zl3073x_out_synth_get(zldev, out);
+
+	/* Get synth's frequency */
+	synth_freq = zl3073x_synth_freq_get(zldev, synth);
+
+	/* Value in register is expressed in half synth clock cycles so
+	 * the given phase adjustment a multiple of half synth clock.
+	 */
+	half_synth_cycle = (int)div_u64(PSEC_PER_SEC, 2 * synth_freq);
+
+	if ((phase_adjust % half_synth_cycle) != 0) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "Phase adjustment value has to be multiple of %d",
+				   half_synth_cycle);
+		return -EINVAL;
+	}
+	phase_adjust /= half_synth_cycle;
+
+	/* The value in the register is stored as two's complement negation
+	 * of requested value.
+	 */
+	phase_adjust = -phase_adjust;
+
+	guard(mutex)(&zldev->multiop_lock);
+
+	/* Read output configuration */
+	rc = zl3073x_mb_op(zldev, ZL_REG_OUTPUT_MB_SEM, ZL_OUTPUT_MB_SEM_RD,
+			   ZL_REG_OUTPUT_MB_MASK, BIT(out));
+	if (rc)
+		return rc;
+
+	/* Write the requested value into the compensation register */
+	rc = zl3073x_write_u32(zldev, ZL_REG_OUTPUT_PHASE_COMP, phase_adjust);
+	if (rc)
+		return rc;
+
+	/* Update output configuration from mailbox */
+	return zl3073x_mb_op(zldev, ZL_REG_OUTPUT_MB_SEM, ZL_OUTPUT_MB_SEM_WR,
+			     ZL_REG_OUTPUT_MB_MASK, BIT(out));
+}
+
 static int
 zl3073x_dpll_output_pin_state_on_dpll_get(const struct dpll_pin *dpll_pin,
 					  void *pin_priv,
@@ -1411,6 +1598,8 @@ static const struct dpll_pin_ops zl3073x_dpll_input_pin_ops = {
 	.frequency_get = zl3073x_dpll_input_pin_frequency_get,
 	.frequency_set = zl3073x_dpll_input_pin_frequency_set,
 	.phase_offset_get = zl3073x_dpll_input_pin_phase_offset_get,
+	.phase_adjust_get = zl3073x_dpll_input_pin_phase_adjust_get,
+	.phase_adjust_set = zl3073x_dpll_input_pin_phase_adjust_set,
 	.prio_get = zl3073x_dpll_input_pin_prio_get,
 	.prio_set = zl3073x_dpll_input_pin_prio_set,
 	.state_on_dpll_get = zl3073x_dpll_input_pin_state_on_dpll_get,
@@ -1423,6 +1612,8 @@ static const struct dpll_pin_ops zl3073x_dpll_output_pin_ops = {
 	.esync_set = zl3073x_dpll_output_pin_esync_set,
 	.frequency_get = zl3073x_dpll_output_pin_frequency_get,
 	.frequency_set = zl3073x_dpll_output_pin_frequency_set,
+	.phase_adjust_get = zl3073x_dpll_output_pin_phase_adjust_get,
+	.phase_adjust_set = zl3073x_dpll_output_pin_phase_adjust_set,
 	.state_on_dpll_get = zl3073x_dpll_output_pin_state_on_dpll_get,
 };
 
diff --git a/drivers/dpll/zl3073x/regs.h b/drivers/dpll/zl3073x/regs.h
index 9ee2f44a2eec7..a382cd4a109f5 100644
--- a/drivers/dpll/zl3073x/regs.h
+++ b/drivers/dpll/zl3073x/regs.h
@@ -168,6 +168,8 @@
 #define ZL_REF_CONFIG_ENABLE			BIT(0)
 #define ZL_REF_CONFIG_DIFF_EN			BIT(2)
 
+#define ZL_REG_REF_PHASE_OFFSET_COMP		ZL_REG(10, 0x28, 6)
+
 #define ZL_REG_REF_SYNC_CTRL			ZL_REG(10, 0x2e, 1)
 #define ZL_REF_SYNC_CTRL_MODE			GENMASK(2, 0)
 #define ZL_REF_SYNC_CTRL_MODE_REFSYNC_PAIR_OFF	0
@@ -237,5 +239,6 @@
 #define ZL_REG_OUTPUT_WIDTH			ZL_REG(14, 0x10, 4)
 #define ZL_REG_OUTPUT_ESYNC_PERIOD		ZL_REG(14, 0x14, 4)
 #define ZL_REG_OUTPUT_ESYNC_WIDTH		ZL_REG(14, 0x18, 4)
+#define ZL_REG_OUTPUT_PHASE_COMP		ZL_REG(14, 0x20, 4)
 
 #endif /* _ZL3073X_REGS_H */
-- 
2.49.1