src/soc/mediatek/common/auxadc.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <assert.h>
   4 #include <delay.h>
   5 #include <device/mmio.h>
   6 #include <soc/addressmap.h>
   7 #include <soc/auxadc.h>
   8 #include <soc/efuse.h>
   9 #include <timer.h>
  10
  11 static struct mtk_auxadc_regs *const mtk_auxadc = (void *)AUXADC_BASE;
  12
  13 #define ADC_GE_A_SHIFT          10
  14 #define ADC_GE_A_MASK           (0x3ff << ADC_GE_A_SHIFT)
  15 #define ADC_OE_A_SHIFT          0
  16 #define ADC_OE_A_MASK           (0x3ff << ADC_OE_A_SHIFT)
  17 #define ADC_CALI_EN_A_SHIFT     20
  18 #define ADC_CALI_EN_A_MASK      (0x1 << ADC_CALI_EN_A_SHIFT)
  19
  20 static int cali_oe;
  21 static int cali_ge;
  22 static int calibrated = 0;
  23 static void mt_auxadc_update_cali(void)
  24 {
  25         uint32_t cali_reg;
  26         int cali_ge_a;
  27         int cali_oe_a;
  28
  29         cali_reg = read32(&mtk_efuse->adc_cali_reg);
  30
  31         if ((cali_reg & ADC_CALI_EN_A_MASK) != 0) {
  32                 cali_oe_a = (cali_reg & ADC_OE_A_MASK) >> ADC_OE_A_SHIFT;
  33                 cali_ge_a = (cali_reg & ADC_GE_A_MASK) >> ADC_GE_A_SHIFT;
  34                 cali_ge = cali_ge_a - 512;
  35                 cali_oe = cali_oe_a - 512;
  36         }
  37 }
  38
  39 static uint32_t auxadc_get_rawdata(int channel)
  40 {
  41         setbits32(&mtk_infracfg->module_sw_cg_1_clr, 1 << 10);
  42         assert(wait_ms(300, !(read32(&mtk_auxadc->con2) & 0x1)));
  43
  44         clrbits32(&mtk_auxadc->con1, 1 << channel);
  45         assert(wait_ms(300, !(read32(&mtk_auxadc->data[channel]) & (1 << 12))));
  46
  47         setbits32(&mtk_auxadc->con1, 1 << channel);
  48         udelay(25);
  49         assert(wait_ms(300, read32(&mtk_auxadc->data[channel]) & (1 << 12)));
  50
  51         uint32_t value = read32(&mtk_auxadc->data[channel]) & 0x0FFF;
  52
  53         setbits32(&mtk_infracfg->module_sw_cg_1_set, 1 << 10);
  54
  55         return value;
  56 }
  57
  58 unsigned int auxadc_get_voltage_uv(unsigned int channel)
  59 {
  60         uint32_t raw_value;
  61         assert(channel < 16);
  62
  63         if (!calibrated) {
  64                 mt_auxadc_update_cali();
  65                 calibrated = 1;
  66         }
  67
  68         /* 1.5V in 4096 steps */
  69         raw_value = auxadc_get_rawdata(channel);
  70         raw_value = raw_value - cali_oe;
  71         return (unsigned int)((int64_t)raw_value * 1500000 / (4096 + cali_ge));
  72 }