zynqmp: pm: Reimplement clock get parent EEMI API

Clock get parent EEMI API is reimplemented to use system-level clock
and pll EEMI APIs rather than direct MMIO read/write accesses to clock
and pll control registers.
Since linux still uses clock set parent API to get pre_src, post_src, div2
and bypasss, in the implementation of pm_clock_get_parent() we need to
workaround this by distinguishing two cases:
1) if the given clock ID corresponds to a PLL-related clock ID (*_PRE_SRC,
   *_POST_SRC, *_INT_MUX or *_PLL clock IDs); or
2) given clock ID is truly an on-chip clock.
For case 1) we'll map the call onto PLL-specific EEMI API with the
respective parameter ID. For case 2) the call is passed to the PMU.
Signed-off-by: Mirela Simonovic <mirela.simonovic@aggios.com>
Acked-by: Will Wong <WILLW@xilinx.com>
Signed-off-by: Jolly Shah <jollys@xilinx.com>

plat/xilinx/zynqmp/pm_service/pm_api_clock.c

@@ -2710,51 +2710,36 @@ enum pm_ret_status pm_clock_pll_set_parent(struct pm_pll *pll,
 }
 
 /**
- * pm_api_clock_getparent - Get the clock parent for given id
+ * pm_clock_pll_get_parent - Get mux select value of PLL-related clock parent
+ * @pll			Target PLL structure
  * @clock_id		Id of the clock
- * @parent_idx	parent index
+ * @parent_index	parent index (=mux select value)
  *
- * This function is used by master to get parent index
- * for any clock.
+ * This function is used by master to get parent index for PLL-related clock.
  *
  * Return: Returns status, either success or error+reason.
  */
-enum pm_ret_status pm_api_clock_getparent(unsigned int clock_id,
-					  unsigned int *parent_idx)
+enum pm_ret_status pm_clock_pll_get_parent(struct pm_pll *pll,
+					   enum clock_id clock_id,
+					   unsigned int *parent_index)
 {
-	enum pm_ret_status ret = PM_RET_SUCCESS;
-	struct pm_clock_node *nodes;
-	uint8_t num_nodes;
-	unsigned int reg, val;
-	uint8_t i = 0, offset = NA_SHIFT, width = NA_WIDTH;
-
-	if (!pm_clock_valid(clock_id))
+	if (!pll)
 		return PM_RET_ERROR_ARGS;
-
-	if (pm_clock_type(clock_id) != CLK_TYPE_OUTPUT)
-		return PM_RET_ERROR_NOTSUPPORTED;
-
-	nodes = *clocks[clock_id].nodes;
-	num_nodes = clocks[clock_id].num_nodes;
-
-	for (i = 0; i < num_nodes; i++) {
-		if (nodes->type == TYPE_MUX) {
-			offset = nodes->offset;
-			width = nodes->width;
-		}
-		nodes++;
+	if (pll->pre_src == clock_id)
+		return pm_pll_get_parameter(pll->nid, PM_PLL_PARAM_PRE_SRC,
+					    parent_index);
+	if (pll->post_src == clock_id)
+		return pm_pll_get_parameter(pll->nid, PM_PLL_PARAM_POST_SRC,
+					    parent_index);
+	if (pll->div2 == clock_id)
+		return pm_pll_get_parameter(pll->nid, PM_PLL_PARAM_DIV2,
+					    parent_index);
+	if (pll->bypass == clock_id) {
+		*parent_index = 0;
+		return PM_RET_SUCCESS;
 	}
-	if (width == NA_WIDTH)
-		return PM_RET_ERROR_NOTSUPPORTED;
 
-	reg = clocks[clock_id].control_reg;
-	ret = pm_mmio_read(reg, &val);
-	val >>= offset;
-	val &= ((1U << width) - 1);
-
-	*parent_idx = val;
-
-	return ret;
+	return PM_RET_ERROR_ARGS;
 }
 
 /**

plat/xilinx/zynqmp/pm_service/pm_api_clock.h

@@ -304,8 +304,9 @@ enum pm_ret_status pm_clock_pll_get_state(struct pm_pll *pll,
 enum pm_ret_status pm_clock_pll_set_parent(struct pm_pll *pll,
 					   enum clock_id clock_id,
 					   unsigned int parent_index);
-enum pm_ret_status pm_api_clock_getparent(unsigned int clock_id,
-					  unsigned int *parent_idx);
+enum pm_ret_status pm_clock_pll_get_parent(struct pm_pll *pll,
+					   enum clock_id clock_id,
+					   unsigned int *parent_index);
 enum pm_ret_status pm_clock_set_pll_mode(enum clock_id clock_id,
 					 unsigned int mode);
 enum pm_ret_status pm_clock_get_pll_mode(enum clock_id clock_id,

plat/xilinx/zynqmp/pm_service/pm_api_sys.c

@@ -1113,7 +1113,7 @@ enum pm_ret_status pm_clock_setparent(unsigned int clock_id,
 /**
  * pm_clock_getparent - Get the clock parent for given id
  * @clock_id: Id of the clock
- * @parent_id: parent id
+ * @parent_index: parent index
  *
  * This function is used by master to get parent index
  * for any clock.
@@ -1121,9 +1121,25 @@ enum pm_ret_status pm_clock_setparent(unsigned int clock_id,
  * Return: Returns status, either success or error+reason.
  */
 enum pm_ret_status pm_clock_getparent(unsigned int clock_id,
-				      unsigned int *parent_id)
+				      unsigned int *parent_index)
 {
-	return pm_api_clock_getparent(clock_id, parent_id);
+	struct pm_pll *pll;
+	uint32_t payload[PAYLOAD_ARG_CNT];
+	enum pm_ret_status status;
+
+	/* First try to handle it as a PLL */
+	pll = pm_clock_get_pll_by_related_clk(clock_id);
+	if (pll)
+		return pm_clock_pll_get_parent(pll, clock_id, parent_index);
+
+	/* Check if clock ID is a valid on-chip clock */
+	status = pm_clock_id_is_valid(clock_id);
+	if (status != PM_RET_SUCCESS)
+		return status;
+
+	/* Send request to the PMU */
+	PM_PACK_PAYLOAD2(payload, PM_CLOCK_GETPARENT, clock_id);
+	return pm_ipi_send_sync(primary_proc, payload, parent_index, 1);
 }
 
 /**