diff options
Diffstat (limited to 'drivers/thermal/ti-soc-thermal/ti-bandgap.c')
| -rw-r--r-- | drivers/thermal/ti-soc-thermal/ti-bandgap.c | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/drivers/thermal/ti-soc-thermal/ti-bandgap.c b/drivers/thermal/ti-soc-thermal/ti-bandgap.c index 62a5d449c388..9747523858a1 100644 --- a/drivers/thermal/ti-soc-thermal/ti-bandgap.c +++ b/drivers/thermal/ti-soc-thermal/ti-bandgap.c @@ -119,6 +119,37 @@ exit: } /** + * ti_errata814_bandgap_read_temp() - helper function to read dra7 sensor temperature + * @bgp: pointer to ti_bandgap structure + * @reg: desired register (offset) to be read + * + * Function to read dra7 bandgap sensor temperature. This is done separately + * so as to workaround the errata "Bandgap Temperature read Dtemp can be + * corrupted" - Errata ID: i814". + * Read accesses to registers listed below can be corrupted due to incorrect + * resynchronization between clock domains. + * Read access to registers below can be corrupted : + * CTRL_CORE_DTEMP_MPU/GPU/CORE/DSPEVE/IVA_n (n = 0 to 4) + * CTRL_CORE_TEMP_SENSOR_MPU/GPU/CORE/DSPEVE/IVA_n + * + * Return: the register value. + */ +static u32 ti_errata814_bandgap_read_temp(struct ti_bandgap *bgp, u32 reg) +{ + u32 val1, val2; + + val1 = ti_bandgap_readl(bgp, reg); + val2 = ti_bandgap_readl(bgp, reg); + + /* If both times we read the same value then that is right */ + if (val1 == val2) + return val1; + + /* if val1 and val2 are different read it third time */ + return ti_bandgap_readl(bgp, reg); +} + +/** * ti_bandgap_read_temp() - helper function to read sensor temperature * @bgp: pointer to ti_bandgap structure * @id: bandgap sensor id @@ -148,7 +179,11 @@ static u32 ti_bandgap_read_temp(struct ti_bandgap *bgp, int id) } /* read temperature */ - temp = ti_bandgap_readl(bgp, reg); + if (TI_BANDGAP_HAS(bgp, ERRATA_814)) + temp = ti_errata814_bandgap_read_temp(bgp, reg); + else + temp = ti_bandgap_readl(bgp, reg); + temp &= tsr->bgap_dtemp_mask; if (TI_BANDGAP_HAS(bgp, FREEZE_BIT)) |