[PATCH v6 4/5] thermal/drivers/sun8i: Add support for A523 THS0/1 controllers

[Mikhail Kalashnikov <iuncuim@gmail.com>]

From: Mikhail Kalashnikov <iuncuim@gmail.com>

The A523 processor has two temperature controllers, THS0 and THS1.
THS0 has only one temperature sensor, which is located in the DRAM
controller. THS1 does have 4 sensors:
ths1_0 - "big" cores
ths1_1 - "little" cores
ths1_2 - gpu
ths1_3 - npu

The user manual for the T527 processor describes 4 sensors, whereas
the one for the A523 describes only 3. As additional information, the BSP
driver was used, in which the value SUN55IW3_CAL_COM(5000) is used as
the calibration value in the formula; in the mainline driver it is
treated as the ft_deviation value. Also, in the BSP driver the NPU sensor
is used for both the GPU and the NPU — its actual purpose is unclear;
both sensors are functional and show temperature changes depending on
load.

Signed-off-by: Mikhail Kalashnikov <iuncuim@gmail.com>
---
 drivers/thermal/sun8i_thermal.c | 147 ++++++++++++++++++++++++++++++++
 1 file changed, 147 insertions(+)

diff --git a/drivers/thermal/sun8i_thermal.c b/drivers/thermal/sun8i_thermal.c
index 360654880..4a81486f8 100644
--- a/drivers/thermal/sun8i_thermal.c
+++ b/drivers/thermal/sun8i_thermal.c
@@ -59,6 +59,12 @@
 #define SUN50I_H6_THS_PC_TEMP_PERIOD(x)		((GENMASK(19, 0) & (x)) << 12)
 #define SUN50I_H6_THS_DATA_IRQ_STS(x)		BIT(x)
 
+#define SUN55I_A523_DELIMITER			0x7c8
+#define SUN55I_A523_OFFSET_BELOW		2736
+#define SUN55I_A523_OFFSET_ABOVE		2825
+#define SUN55I_A523_SCALE_BELOW			74
+#define SUN55I_A523_SCALE_ABOVE			65
+
 struct tsensor {
 	struct ths_device		*tmdev;
 	struct thermal_zone_device	*tzd;
@@ -114,6 +120,21 @@ static int sun50i_h5_calc_temp(struct ths_device *tmdev,
 		return -1590 * reg / 10 + 276000;
 }
 
+/*
+ * The constant names were chosen in accordance with the BSP driver;
+ * they indicate whether the value corresponds to a high or low
+ * temperature (relative to a value of ~55 °C), rather than the reg value
+ * that was read.
+ */
+static int sun55i_a523_calc_temp(struct ths_device *tmdev,
+				 int id, int reg)
+{
+	if (reg >= SUN55I_A523_DELIMITER)
+		return SUN55I_A523_SCALE_BELOW * (SUN55I_A523_OFFSET_BELOW - reg);
+	else
+		return SUN55I_A523_SCALE_ABOVE * (SUN55I_A523_OFFSET_ABOVE - reg);
+}
+
 static int sun8i_ths_get_temp(struct thermal_zone_device *tz, int *temp)
 {
 	struct tsensor *s = thermal_zone_device_priv(tz);
@@ -298,6 +319,105 @@ static int sun50i_h6_ths_calibrate(struct ths_device *tmdev,
 	return 0;
 }
 
+/*
+ * The A523 calibration data is stored in the eFuse, split across two
+ * nvmem cells. THS1 has four sensors, including ths1_3 which is used
+ * for the NPU, each with its own calibration value. The fields are
+ * packed as shown in the layouts below.
+ *
+ * efuse layout 0x38-0x3F (caldata[0..3]):
+ *     caldata[0]      caldata[1]      caldata[2]      caldata[3]
+ * 0               16      24      32  36          48          60 64
+ * +---------------+---------------+---------------+---------------+
+ * |               |       |   temp    |  ths1_0   |  ths1_1   |   +
+ * +---------------+---------------+---------------+---------------+
+ *
+ * efuse layout 0x44-0x4B (caldata[4..7]):
+ *     caldata[4]      caldata[5]      caldata[6]      caldata[7]
+ * 0           12  16      24      32  36          48             64
+ * +---------------+---------------+---------------+---------------+
+ * |  ths1_2   |  ths1_3   |    ths0   |           |               +
+ * +---------------+---------------+---------------+---------------+
+ */
+static int sun55i_a523_ths_calibrate(struct ths_device *tmdev,
+				     u16 *caldata, int callen)
+{
+	struct device *dev = tmdev->dev;
+	int i, ft_temp;
+
+	if (!caldata[1])
+		return -EINVAL;
+
+	ft_temp = (((caldata[2] << 8) | (caldata[1] >> 8)) & FT_TEMP_MASK) * 100;
+
+	for (i = 0; i < tmdev->chip->sensor_num; i++) {
+		int sensor_reg, sensor_temp, cdata, offset;
+		/*
+		 * Chips ths0 and ths1 have common parameters for value
+		 * calibration. To separate them we can use the number of
+		 * temperature sensors on each chip.
+		 * For ths0 this value is 1.
+		 */
+		if (tmdev->chip->sensor_num == 1) {
+			sensor_reg = ((caldata[5] >> 8) |
+				      (caldata[6] << 8)) & TEMP_CALIB_MASK;
+		} else {
+			switch (i) {
+			case 0:
+				sensor_reg = (caldata[2] >> 4) & TEMP_CALIB_MASK;
+				break;
+			case 1:
+				sensor_reg = caldata[3] & TEMP_CALIB_MASK;
+				break;
+			case 2:
+				sensor_reg = caldata[4] & TEMP_CALIB_MASK;
+				break;
+			case 3:
+				sensor_reg = ((caldata[4] >> 12) |
+					      (caldata[5] << 4)) & TEMP_CALIB_MASK;
+				break;
+			default:
+				sensor_reg = 0;
+				break;
+			}
+		}
+
+		sensor_temp = tmdev->chip->calc_temp(tmdev, i, sensor_reg);
+
+		/*
+		 * Calibration data is CALIBRATE_DEFAULT - (calculated
+		 * temperature from sensor reading at factory temperature
+		 * minus actual factory temperature) * X (scale from
+		 * temperature to register values).
+		 *
+		 * The BSP's SUN55IW3_CAL_COM(5000) is applied as ft_deviation
+		 * in sun8i_ths_get_temp(), after calc_temp(), and therefore
+		 * intentionally not repeated here.
+		 */
+		cdata = CALIBRATE_DEFAULT -
+			((sensor_temp - ft_temp) / SUN55I_A523_SCALE_BELOW);
+
+		if (cdata & ~TEMP_CALIB_MASK) {
+			/*
+			 * Calibration value more than 12-bit, but calibration
+			 * register is 12-bit. In this case, ths hardware can
+			 * still work without calibration, although the data
+			 * won't be so accurate.
+			 */
+			dev_warn(dev, "sensor%d is not calibrated.\n", i);
+			continue;
+		}
+
+		offset = (i % 2) * 16;
+		regmap_update_bits(tmdev->regmap,
+				   SUN50I_H6_THS_TEMP_CALIB + (i / 2 * 4),
+				   TEMP_CALIB_MASK << offset,
+				   cdata << offset);
+	}
+
+	return 0;
+}
+
 static int sun8i_ths_calibrate(struct ths_device *tmdev)
 {
 	struct nvmem_cell *calcell = NULL;
@@ -719,6 +839,31 @@ static const struct ths_thermal_chip sun50i_h616_ths = {
 	.calc_temp = sun8i_ths_calc_temp,
 };
 
+/* The A523 has a shared reset line for both chips */
+static const struct ths_thermal_chip sun55i_a523_ths0 = {
+	.sensor_num = 1,
+	.has_bus_clk_reset = true,
+	.has_mod_clk = true,
+	.ft_deviation = 5000,
+	.temp_data_base = SUN50I_H6_THS_TEMP_DATA,
+	.calibrate = sun55i_a523_ths_calibrate,
+	.init = sun50i_h6_thermal_init,
+	.irq_ack = sun50i_h6_irq_ack,
+	.calc_temp = sun55i_a523_calc_temp,
+};
+
+static const struct ths_thermal_chip sun55i_a523_ths1 = {
+	.sensor_num = 4,
+	.has_bus_clk_reset = true,
+	.has_mod_clk = true,
+	.ft_deviation = 5000,
+	.temp_data_base = SUN50I_H6_THS_TEMP_DATA,
+	.calibrate = sun55i_a523_ths_calibrate,
+	.init = sun50i_h6_thermal_init,
+	.irq_ack = sun50i_h6_irq_ack,
+	.calc_temp = sun55i_a523_calc_temp,
+};
+
 static const struct of_device_id of_ths_match[] = {
 	{ .compatible = "allwinner,sun8i-a83t-ths", .data = &sun8i_a83t_ths },
 	{ .compatible = "allwinner,sun8i-h3-ths", .data = &sun8i_h3_ths },
@@ -729,6 +874,8 @@ static const struct of_device_id of_ths_match[] = {
 	{ .compatible = "allwinner,sun50i-h6-ths", .data = &sun50i_h6_ths },
 	{ .compatible = "allwinner,sun20i-d1-ths", .data = &sun20i_d1_ths },
 	{ .compatible = "allwinner,sun50i-h616-ths", .data = &sun50i_h616_ths },
+	{ .compatible = "allwinner,sun55i-a523-ths0", .data = &sun55i_a523_ths0 },
+	{ .compatible = "allwinner,sun55i-a523-ths1", .data = &sun55i_a523_ths1 },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, of_ths_match);
-- 
2.55.0