arch/arm/cpu/arm926ejs/mxs/spl_lradc_init.c

   1 /*
   2  * Freescale i.MX28 Battery measurement init
   3  *
   4  * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
   5  * on behalf of DENX Software Engineering GmbH
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 #include <common.h>
  11 #include <config.h>
  12 #include <asm/io.h>
  13 #include <asm/arch/imx-regs.h>
  14
  15 #include "mxs_init.h"
  16
  17 void mxs_lradc_init(void)
  18 {
  19         struct mxs_lradc_regs *regs = (struct mxs_lradc_regs *)MXS_LRADC_BASE;
  20
  21         writel(LRADC_CTRL0_SFTRST, &regs->hw_lradc_ctrl0_clr);
  22         writel(LRADC_CTRL0_CLKGATE, &regs->hw_lradc_ctrl0_clr);
  23         writel(LRADC_CTRL0_ONCHIP_GROUNDREF, &regs->hw_lradc_ctrl0_clr);
  24
  25         clrsetbits_le32(&regs->hw_lradc_ctrl3,
  26                         LRADC_CTRL3_CYCLE_TIME_MASK,
  27                         LRADC_CTRL3_CYCLE_TIME_6MHZ);
  28
  29         clrsetbits_le32(&regs->hw_lradc_ctrl4,
  30                         LRADC_CTRL4_LRADC7SELECT_MASK |
  31                         LRADC_CTRL4_LRADC6SELECT_MASK,
  32                         LRADC_CTRL4_LRADC7SELECT_CHANNEL7 |
  33                         LRADC_CTRL4_LRADC6SELECT_CHANNEL10);
  34 }
  35
  36 void mxs_lradc_enable_batt_measurement(void)
  37 {
  38         struct mxs_lradc_regs *regs = (struct mxs_lradc_regs *)MXS_LRADC_BASE;
  39
  40         /* Check if the channel is present at all. */
  41         if (!(readl(&regs->hw_lradc_status) & LRADC_STATUS_CHANNEL7_PRESENT))
  42                 return;
  43
  44         writel(LRADC_CTRL1_LRADC7_IRQ_EN, &regs->hw_lradc_ctrl1_clr);
  45         writel(LRADC_CTRL1_LRADC7_IRQ, &regs->hw_lradc_ctrl1_clr);
  46
  47         clrsetbits_le32(&regs->hw_lradc_conversion,
  48                         LRADC_CONVERSION_SCALE_FACTOR_MASK,
  49                         LRADC_CONVERSION_SCALE_FACTOR_LI_ION);
  50         writel(LRADC_CONVERSION_AUTOMATIC, &regs->hw_lradc_conversion_set);
  51
  52         /* Configure the channel. */
  53         writel((1 << 7) << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
  54                 &regs->hw_lradc_ctrl2_clr);
  55         writel(0xffffffff, &regs->hw_lradc_ch7_clr);
  56         clrbits_le32(&regs->hw_lradc_ch7, LRADC_CH_NUM_SAMPLES_MASK);
  57         writel(LRADC_CH_ACCUMULATE, &regs->hw_lradc_ch7_clr);
  58
  59         /* Schedule the channel. */
  60         writel(1 << 7, &regs->hw_lradc_ctrl0_set);
  61
  62         /* Start the channel sampling. */
  63         writel(((1 << 7) << LRADC_DELAY_TRIGGER_LRADCS_OFFSET) |
  64                 ((1 << 3) << LRADC_DELAY_TRIGGER_DELAYS_OFFSET) |
  65                 100, &regs->hw_lradc_delay3);
  66
  67         writel(0xffffffff, &regs->hw_lradc_ch7_clr);
  68
  69         writel(LRADC_DELAY_KICK, &regs->hw_lradc_delay3_set);
  70 }