+++ /dev/null
-From 14f118aa50fe7c7c7330f56d007ecacca487cea8 Mon Sep 17 00:00:00 2001
-From: Andre Przywara <andre.przywara@arm.com>
-Date: Mon, 19 Feb 2024 15:36:35 +0000
-Subject: [PATCH] thermal/drivers/sun8i: Explain unknown H6 register value
-
-So far we were ORing in some "unknown" value into the THS control
-register on the Allwinner H6. This part of the register is not explained
-in the H6 manual, but the H616 manual details those bits, and on closer
-inspection the THS IP blocks in both SoCs seem very close:
-- The BSP code for both SoCs writes the same values into THS_CTRL.
-- The reset values of at least the first three registers are the same.
-
-Replace the "unknown" value with its proper meaning: "acquire time",
-most probably the sample part of the sample & hold circuit of the ADC,
-according to its explanation in the H616 manual.
-
-No functional change, just a macro rename and adjustment.
-
-Signed-off-by: Andre Przywara <andre.przywara@arm.com>
-Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
-Acked-by: Vasily Khoruzhick <anarsoul@gmail.com>
-Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
-Link: https://lore.kernel.org/r/20240219153639.179814-4-andre.przywara@arm.com
----
- drivers/thermal/sun8i_thermal.c | 29 ++++++++++++++++-------------
- 1 file changed, 16 insertions(+), 13 deletions(-)
-
---- a/drivers/thermal/sun8i_thermal.c
-+++ b/drivers/thermal/sun8i_thermal.c
-@@ -50,7 +50,8 @@
- #define SUN8I_THS_CTRL2_T_ACQ1(x) ((GENMASK(15, 0) & (x)) << 16)
- #define SUN8I_THS_DATA_IRQ_STS(x) BIT(x + 8)
-
--#define SUN50I_THS_CTRL0_T_ACQ(x) ((GENMASK(15, 0) & (x)) << 16)
-+#define SUN50I_THS_CTRL0_T_ACQ(x) (GENMASK(15, 0) & ((x) - 1))
-+#define SUN50I_THS_CTRL0_T_SAMPLE_PER(x) ((GENMASK(15, 0) & ((x) - 1)) << 16)
- #define SUN50I_THS_FILTER_EN BIT(2)
- #define SUN50I_THS_FILTER_TYPE(x) (GENMASK(1, 0) & (x))
- #define SUN50I_H6_THS_PC_TEMP_PERIOD(x) ((GENMASK(19, 0) & (x)) << 12)
-@@ -410,25 +411,27 @@ static int sun8i_h3_thermal_init(struct
- return 0;
- }
-
--/*
-- * Without this undocumented value, the returned temperatures would
-- * be higher than real ones by about 20C.
-- */
--#define SUN50I_H6_CTRL0_UNK 0x0000002f
--
- static int sun50i_h6_thermal_init(struct ths_device *tmdev)
- {
- int val;
-
- /*
-- * T_acq = 20us
-- * clkin = 24MHz
-- *
-- * x = T_acq * clkin - 1
-- * = 479
-+ * The manual recommends an overall sample frequency of 50 KHz (20us,
-+ * 480 cycles at 24 MHz), which provides plenty of time for both the
-+ * acquisition time (>24 cycles) and the actual conversion time
-+ * (>14 cycles).
-+ * The lower half of the CTRL register holds the "acquire time", in
-+ * clock cycles, which the manual recommends to be 2us:
-+ * 24MHz * 2us = 48 cycles.
-+ * The high half of THS_CTRL encodes the sample frequency, in clock
-+ * cycles: 24MHz * 20us = 480 cycles.
-+ * This is explained in the H616 manual, but apparently wrongly
-+ * described in the H6 manual, although the BSP code does the same
-+ * for both SoCs.
- */
- regmap_write(tmdev->regmap, SUN50I_THS_CTRL0,
-- SUN50I_H6_CTRL0_UNK | SUN50I_THS_CTRL0_T_ACQ(479));
-+ SUN50I_THS_CTRL0_T_ACQ(48) |
-+ SUN50I_THS_CTRL0_T_SAMPLE_PER(480));
- /* average over 4 samples */
- regmap_write(tmdev->regmap, SUN50I_H6_THS_MFC,
- SUN50I_THS_FILTER_EN |
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