clk: msm: clock-osm: add support for MEM ACC threshold voltage

Add support for configuring the highest memory accelerator
(MEM ACC) threshold voltage.  This threshold voltage is used at
runtime to determine which CPRh virtual corner to program into
the OSM sequencer registers in place of the fixed MEM ACC
configuration specified in the OSM LUT.

CRs-Fixed: 1088429
Change-Id: Ida29eaca139c1ddd6439d11a8bd51526366f2a34
Signed-off-by: David Collins <collinsd@codeaurora.org>

Documentation/devicetree/bindings/arm/msm/qcom,osm.txt

@@ -289,6 +289,16 @@ Properties:
 		    values per performance mode with a total of 4 tuples
 		    corresponding to each supported performance mode.
 
+- qcom,perfcl-apcs-mem-acc-threshold-voltage
+	Usage:      optional
+	Value type: <u32>
+	Definition: Specifies the highest MEM ACC threshold voltage in
+		    microvolts for the Performance cluster.  This voltage is
+		    used to determine which MEM ACC setting is used for the
+		    highest frequencies.  If specified, the voltage must match
+		    the MEM ACC threshold voltage specified for the
+		    corresponding CPRh device.
+
 - qcom,red-fsm-en
 	Usage:      optional
 	Value type: <empty>

drivers/clk/msm/clock-osm.c

@@ -359,6 +359,8 @@ struct clk_osm {
 	u32 irq;
 	u32 apm_crossover_vc;
 	u32 apm_threshold_vc;
+	u32 mem_acc_crossover_vc;
+	u32 mem_acc_threshold_vc;
 	u32 cycle_counter_reads;
 	u32 cycle_counter_delay;
 	u32 cycle_counter_factor;
@@ -845,6 +847,8 @@ static void clk_osm_print_osm_table(struct clk_osm *c)
 	}
 	pr_debug("APM threshold corner=%d, crossover corner=%d\n",
 		 c->apm_threshold_vc, c->apm_crossover_vc);
+	pr_debug("MEM-ACC threshold corner=%d, crossover corner=%d\n",
+		 c->mem_acc_threshold_vc, c->mem_acc_crossover_vc);
 }
 
 static int clk_osm_get_lut(struct platform_device *pdev,
@@ -1523,20 +1527,27 @@ static int clk_osm_resolve_open_loop_voltages(struct clk_osm *c)
 }
 
 static int clk_osm_resolve_crossover_corners(struct clk_osm *c,
-				     struct platform_device *pdev)
+				     struct platform_device *pdev,
+				     const char *mem_acc_prop)
 {
 	struct regulator *regulator = c->vdd_reg;
-	int count, vc, i, threshold, rc = 0;
+	int count, vc, i, apm_threshold;
+	int mem_acc_threshold = 0;
+	int rc = 0;
 	u32 corner_volt;
 
 	rc = of_property_read_u32(pdev->dev.of_node,
 				  "qcom,apm-threshold-voltage",
-				  &threshold);
+				  &apm_threshold);
 	if (rc) {
 		pr_info("qcom,apm-threshold-voltage property not specified\n");
 		return rc;
 	}
 
+	if (mem_acc_prop)
+		of_property_read_u32(pdev->dev.of_node, mem_acc_prop,
+					  &mem_acc_threshold);
+
 	/* Determine crossover virtual corner */
 	count = regulator_count_voltages(regulator);
 	if (count < 0) {
@@ -1544,19 +1555,49 @@ static int clk_osm_resolve_crossover_corners(struct clk_osm *c,
 		return count;
 	}
 
-	c->apm_crossover_vc = count - 1;
+	/*
+	 * CPRh corners (in hardware) are ordered:
+	 * 0 - n-1		- for n functional corners
+	 * APM crossover	- required for OSM
+	 * [MEM ACC crossover]	- optional
+	 *
+	 * 'count' corresponds to the total number of corners including n
+	 * functional corners, the APM crossover corner, and potentially the
+	 * MEM ACC cross over corner.
+	 */
+	if (mem_acc_threshold) {
+		c->apm_crossover_vc = count - 2;
+		c->mem_acc_crossover_vc = count - 1;
+	} else {
+		c->apm_crossover_vc = count - 1;
+	}
 
-	/* Determine threshold virtual corner */
+	/* Determine APM threshold virtual corner */
 	for (i = 0; i < OSM_TABLE_SIZE; i++) {
 		vc = c->osm_table[i].virtual_corner + 1;
 		corner_volt = regulator_list_corner_voltage(regulator, vc);
 
-		if (corner_volt >= threshold) {
+		if (corner_volt >= apm_threshold) {
 			c->apm_threshold_vc = c->osm_table[i].virtual_corner;
 			break;
 		}
 	}
 
+	/* Determine MEM ACC threshold virtual corner */
+	if (mem_acc_threshold) {
+		for (i = 0; i < OSM_TABLE_SIZE; i++) {
+			vc = c->osm_table[i].virtual_corner + 1;
+			corner_volt
+				= regulator_list_corner_voltage(regulator, vc);
+
+			if (corner_volt >= mem_acc_threshold) {
+				c->mem_acc_threshold_vc
+					= c->osm_table[i].virtual_corner;
+				break;
+			}
+		}
+	}
+
 	return 0;
 }
 
@@ -1855,6 +1896,7 @@ static void clk_osm_program_mem_acc_regs(struct clk_osm *c)
 {
 	int i, curr_level, j = 0;
 	int mem_acc_level_map[MAX_MEM_ACC_LEVELS] = {0, 0, 0};
+	int threshold_vc[4];
 
 	curr_level = c->osm_table[0].spare_data;
 	for (i = 0; i < c->num_entries; i++) {
@@ -1889,14 +1931,37 @@ static void clk_osm_program_mem_acc_regs(struct clk_osm *c)
 			clk_osm_write_reg(c, c->apcs_mem_acc_cfg[i],
 					  MEM_ACC_SEQ_REG_CFG_START(i));
 	} else {
+		if (c->mem_acc_crossover_vc)
+			scm_io_write(c->pbases[OSM_BASE] + SEQ_REG(88),
+					c->mem_acc_crossover_vc);
+
+		threshold_vc[0] = mem_acc_level_map[0];
+		threshold_vc[1] = mem_acc_level_map[0] + 1;
+		threshold_vc[2] = mem_acc_level_map[1];
+		threshold_vc[3] = mem_acc_level_map[1] + 1;
+
+		/*
+		 * Use dynamic MEM ACC threshold voltage based value for the
+		 * highest MEM ACC threshold if it is specified instead of the
+		 * fixed mapping in the LUT.
+		 */
+		if (c->mem_acc_threshold_vc) {
+			threshold_vc[2] = c->mem_acc_threshold_vc - 1;
+			threshold_vc[3] = c->mem_acc_threshold_vc;
+			if (threshold_vc[1] >= threshold_vc[2])
+				threshold_vc[1] = threshold_vc[2] - 1;
+			if (threshold_vc[0] >= threshold_vc[1])
+				threshold_vc[0] = threshold_vc[1] - 1;
+		}
+
 		scm_io_write(c->pbases[OSM_BASE] + SEQ_REG(55),
-			     mem_acc_level_map[0]);
+				threshold_vc[0]);
 		scm_io_write(c->pbases[OSM_BASE] + SEQ_REG(56),
-			     mem_acc_level_map[0] + 1);
+				threshold_vc[1]);
 		scm_io_write(c->pbases[OSM_BASE] + SEQ_REG(57),
-			     mem_acc_level_map[1]);
+				threshold_vc[2]);
 		scm_io_write(c->pbases[OSM_BASE] + SEQ_REG(58),
-			     mem_acc_level_map[1] + 1);
+				threshold_vc[3]);
 		/* SEQ_REG(49) = SEQ_REG(28) init by TZ */
 	}
 
@@ -3110,13 +3175,14 @@ static int cpu_clock_osm_driver_probe(struct platform_device *pdev)
 		return rc;
 	}
 
-	rc = clk_osm_resolve_crossover_corners(&pwrcl_clk, pdev);
+	rc = clk_osm_resolve_crossover_corners(&pwrcl_clk, pdev, NULL);
 	if (rc)
 		dev_info(&pdev->dev, "No APM crossover corner programmed\n");
 
-	rc = clk_osm_resolve_crossover_corners(&perfcl_clk, pdev);
+	rc = clk_osm_resolve_crossover_corners(&perfcl_clk, pdev,
+				"qcom,perfcl-apcs-mem-acc-threshold-voltage");
 	if (rc)
-		dev_info(&pdev->dev, "No APM crossover corner programmed\n");
+		dev_info(&pdev->dev, "No MEM-ACC crossover corner programmed\n");
 
 	clk_osm_setup_cycle_counters(&pwrcl_clk);
 	clk_osm_setup_cycle_counters(&perfcl_clk);