clk: tegra: dfll: CVB calculation alignment with the regulator

The CVB table contains calibration data for the CPU DFLL based on
process characterization. The regulator step and offset parameters depend
on the regulator supplying vdd-cpu, not on the specific Tegra SKU.

When using a PWM controlled regulator, the voltage step and offset are
determined by the regulator type in use. This is specified in DT. When
using an I2C controlled regulator, we can retrieve them from CPU regulator
Then pass this information to the CVB table calculation function.

Based on the work done of "Peter De Schrijver <pdeschrijver@nvidia.com>"
and "Alex Frid <afrid@nvidia.com>".

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 44 insertions, 5 deletions

diff --git a/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c b/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c
index 2bf6a769e5ce..92b83f50a765 100644
--- a/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c
+++ b/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c
@@ -23,6 +23,7 @@
 #include <linux/init.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
 #include <soc/tegra/fuse.h>
 
 #include "clk.h"
@@ -50,9 +51,6 @@ static const struct cvb_table tegra124_cpu_cvb_tables[] = {
 		.process_id = -1,
 		.min_millivolts = 900,
 		.max_millivolts = 1260,
-		.alignment = {
-			.step_uv = 10000, /* 10mV */
-		},
 		.speedo_scale = 100,
 		.voltage_scale = 1000,
 		.entries = {
@@ -105,11 +103,42 @@ static const struct of_device_id tegra124_dfll_fcpu_of_match[] = {
 	{ },
 };
 
+static void get_alignment_from_dt(struct device *dev,
+				  struct rail_alignment *align)
+{
+	if (of_property_read_u32(dev->of_node,
+				 "nvidia,pwm-voltage-step-microvolts",
+				 &align->step_uv))
+		align->step_uv = 0;
+
+	if (of_property_read_u32(dev->of_node,
+				 "nvidia,pwm-min-microvolts",
+				 &align->offset_uv))
+		align->offset_uv = 0;
+}
+
+static int get_alignment_from_regulator(struct device *dev,
+					 struct rail_alignment *align)
+{
+	struct regulator *reg = devm_regulator_get(dev, "vdd-cpu");
+
+	if (IS_ERR(reg))
+		return PTR_ERR(reg);
+
+	align->offset_uv = regulator_list_voltage(reg, 0);
+	align->step_uv = regulator_get_linear_step(reg);
+
+	devm_regulator_put(reg);
+
+	return 0;
+}
+
 static int tegra124_dfll_fcpu_probe(struct platform_device *pdev)
 {
 	int process_id, speedo_id, speedo_value, err;
 	struct tegra_dfll_soc_data *soc;
 	const struct dfll_fcpu_data *fcpu_data;
+	struct rail_alignment align;
 
 	fcpu_data = of_device_get_match_data(&pdev->dev);
 	if (!fcpu_data)
@@ -135,12 +164,22 @@ static int tegra124_dfll_fcpu_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
+	if (of_property_read_bool(pdev->dev.of_node, "nvidia,pwm-to-pmic")) {
+		get_alignment_from_dt(&pdev->dev, &align);
+	} else {
+		err = get_alignment_from_regulator(&pdev->dev, &align);
+		if (err)
+			return err;
+	}
+
 	soc->max_freq = fcpu_data->cpu_max_freq_table[speedo_id];
 
 	soc->cvb = tegra_cvb_add_opp_table(soc->dev, fcpu_data->cpu_cvb_tables,
 					   fcpu_data->cpu_cvb_tables_size,
-					   process_id, speedo_id, speedo_value,
-					   soc->max_freq);
+					   &align, process_id, speedo_id,
+					   speedo_value, soc->max_freq);
+	soc->alignment = align;
+
 	if (IS_ERR(soc->cvb)) {
 		dev_err(&pdev->dev, "couldn't add OPP table: %ld\n",
 			PTR_ERR(soc->cvb));