diff options
Diffstat (limited to 'drivers/thermal/sun8i_thermal.c')
| -rw-r--r-- | drivers/thermal/sun8i_thermal.c | 29 |
1 files changed, 16 insertions, 13 deletions
diff --git a/drivers/thermal/sun8i_thermal.c b/drivers/thermal/sun8i_thermal.c index 6a8e386dbc8d..42bee03c4e50 100644 --- 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 ths_device *tmdev) 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 | |