-static u32 __data thermal_calib;
-
-#define FACTOR0 10000000
-#define FACTOR1 15976
-#define FACTOR2 4297157
-
-int raw_to_celsius(unsigned int raw, unsigned int raw_25c, unsigned int raw_hot,
- unsigned int hot_temp)
-{
- int temperature;
-
- if (raw_hot != 0 && hot_temp != 0) {
- unsigned int raw_n40c, ratio;
-
- ratio = ((raw_25c - raw_hot) * 100) / (hot_temp - 25);
- raw_n40c = raw_25c + (13 * ratio) / 20;
- if (raw <= raw_n40c)
- temperature = (raw_n40c - raw) * 100 / ratio - 40;
- else
- temperature = TEMPERATURE_MIN;
- } else {
- u64 temp64 = FACTOR0;
- unsigned int c1, c2;
- /*
- * Derived from linear interpolation:
- * slope = 0.4297157 - (0.0015976 * 25C fuse)
- * slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0
- * (Nmeas - n1) / (Tmeas - t1) = slope
- * We want to reduce this down to the minimum computation necessary
- * for each temperature read. Also, we want Tmeas in millicelsius
- * and we don't want to lose precision from integer division. So...
- * Tmeas = (Nmeas - n1) / slope + t1
- * milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1
- * milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1
- * Let constant c1 = (-1000 / slope)
- * milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1
- * Let constant c2 = n1 *c1 + 1000 * t1
- * milli_Tmeas = c2 - Nmeas * c1
- */
- temp64 *= 1000;
- do_div(temp64, FACTOR1 * raw_25c - FACTOR2);
- c1 = temp64;
- c2 = raw_25c * c1 + 1000 * 25;
- temperature = (c2 - raw * c1) / 1000;
- }
- return temperature;
-}
-
-int read_cpu_temperature(void)
-{
- unsigned int reg, tmp, i;
- unsigned int raw_25c, raw_hot, hot_temp;
- int temperature;
- struct anatop_regs *const anatop = (void *)ANATOP_BASE_ADDR;
- struct mx6_ocotp_regs *const ocotp_regs = (void *)OCOTP_BASE_ADDR;
-
- if (!thermal_calib) {
- if (fuse_read(1, 6, &thermal_calib) != 0) {
- printf("Failed to read thermal calibration data\n");
- thermal_calib = ~0;
- }
- }
-
- if (thermal_calib == 0 || thermal_calib == 0xffffffff)
- return TEMPERATURE_MIN;
-
- /* Fuse data layout:
- * [31:20] sensor value @ 25C
- * [19:8] sensor value of hot
- * [7:0] hot temperature value */
- raw_25c = thermal_calib >> 20;
- raw_hot = (thermal_calib & 0xfff00) >> 8;
- hot_temp = thermal_calib & 0xff;
-
- /* now we only using single measure, every time we measure
- * the temperature, we will power on/off the anadig module
- */
- writel(BM_ANADIG_TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_clr);
- writel(BM_ANADIG_ANA_MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_set);
-
- /* write measure freq */
- writel(327, &anatop->tempsense1);
- writel(BM_ANADIG_TEMPSENSE0_MEASURE_TEMP, &anatop->tempsense0_clr);
- writel(BM_ANADIG_TEMPSENSE0_FINISHED, &anatop->tempsense0_clr);
- writel(BM_ANADIG_TEMPSENSE0_MEASURE_TEMP, &anatop->tempsense0_set);
-
- /* average the temperature value over multiple readings */
- for (i = 0; i < TEMP_AVG_COUNT; i++) {
- static int failed;
- int limit = 100;
-
- while ((readl(&anatop->tempsense0) &
- BM_ANADIG_TEMPSENSE0_FINISHED) == 0) {
- udelay(10000);
- if (--limit < 0)
- break;
- }
- if ((readl(&anatop->tempsense0) &
- BM_ANADIG_TEMPSENSE0_FINISHED) == 0) {
- if (!failed) {
- printf("Failed to read temp sensor\n");
- failed = 1;
- }
- return 0;
- }
- failed = 0;
- reg = (readl(&anatop->tempsense0) &
- BM_ANADIG_TEMPSENSE0_TEMP_VALUE) >>
- BP_ANADIG_TEMPSENSE0_TEMP_VALUE;
- if (i == 0)
- tmp = reg;
- else
- tmp = (tmp * i + reg) / (i + 1);
- writel(BM_ANADIG_TEMPSENSE0_FINISHED,
- &anatop->tempsense0_clr);
- }
-
- temperature = raw_to_celsius(tmp, raw_25c, raw_hot, hot_temp);
-
- /* power down anatop thermal sensor */
- writel(BM_ANADIG_TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_set);
- writel(BM_ANADIG_ANA_MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_clr);
-
- return temperature;
-}
-