src/soc/rockchip/rk3399/saradc.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <device/mmio.h>
   4 #include <assert.h>
   5 #include <delay.h>
   6 #include <soc/clock.h>
   7 #include <soc/saradc.h>
   8 #include <stdint.h>
   9 #include <timer.h>
  10
  11 struct rk3399_saradc_regs {
  12         u32 data;
  13         u32 stas;
  14         u32 ctrl;
  15         u32 dly_pu_soc;
  16 };
  17 check_member(rk3399_saradc_regs, dly_pu_soc, 0xc);
  18
  19 struct rk3399_saradc_regs *rk3399_saradc = (void *)SARADC_BASE;
  20
  21 /* SARADC_STAS: conversion done */
  22 #define ADC_STOP        0
  23
  24 /* SARADC_CTRL */
  25 #define INT_EN                  (1 << 5)
  26 #define ADC_PWR_CTRL            (1 << 3)
  27 #define ADC_CHN_SEL_MASK        7
  28 #define ADC_CHN_SEL_SHIFT       0
  29
  30 /* SARADC_DATA, 10[0:9] bits */
  31 #define DATA_MASK               0x3FF
  32
  33 #define SARADC_HZ               (4*MHz)
  34
  35 #define SARADC_MAX_CHANNEL      6
  36
  37 #define SARADC_DELAY_PU                (1 * 1000 * 1000 * 1000 / SARADC_HZ * 4)
  38
  39 u32 get_saradc_value(u32 chn)
  40 {
  41         u32 adc_value;
  42         struct stopwatch sw;
  43
  44         assert(chn < SARADC_MAX_CHANNEL);
  45         rkclk_configure_saradc(SARADC_HZ);
  46
  47         /* power down adc converter */
  48         clrbits32(&rk3399_saradc->ctrl, ADC_PWR_CTRL);
  49
  50         /* select channel */
  51         clrsetbits32(&rk3399_saradc->ctrl,
  52                      ADC_CHN_SEL_MASK << ADC_CHN_SEL_SHIFT,
  53                      chn << ADC_CHN_SEL_SHIFT);
  54
  55         /* power up */
  56         setbits32(&rk3399_saradc->ctrl, ADC_PWR_CTRL);
  57
  58         udelay(SARADC_DELAY_PU);
  59
  60         stopwatch_init_msecs_expire(&sw, 10);
  61         do {
  62                 if (read32(&rk3399_saradc->stas) == ADC_STOP) {
  63                         adc_value = read32(&rk3399_saradc->data) & DATA_MASK;
  64                         return adc_value;
  65                 }
  66         } while (!stopwatch_expired(&sw));
  67
  68         return -1;
  69 }