rtc.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
/*
 * This file is created based on MT8186 Functional Specification
 * Chapter number: 5.13
 */
 
#include <delay.h>
#include <halt.h>
#include <soc/rtc.h>
#include <soc/rtc_common.h>
#include <soc/mt6366.h>
#include <soc/pmic_wrap.h>
#include <timer.h>
 
#define MT8186_RTC_DXCO_CAPID 0xE0
 
/* Initialize RTC setting of using DCXO clock */
static bool rtc_enable_dcxo(void)
{
        u16 bbpu, con, osc32con, sec;
 
        rtc_read(RTC_BBPU, &bbpu);
        rtc_write(RTC_BBPU, bbpu | RTC_BBPU_KEY | RTC_BBPU_RELOAD);
 
        if (!rtc_write_trigger()) {
                rtc_info("rtc_write_trigger() failed\n");
                return false;
        }
 
        mdelay(1);
        if (!rtc_writeif_unlock()) {
                rtc_info("rtc_writeif_unlock() failed\n");
                return false;
        }
 
        rtc_read(RTC_OSC32CON, &osc32con);
        osc32con &= ~(RTC_EMBCK_SRC_SEL | RTC_EMBCK_SEL_MODE_MASK
                      | RTC_GPS_CKOUT_EN);
        osc32con |= RTC_XOSC32_ENB | RTC_REG_XOSC32_ENB
                    | RTC_EMB_K_EOSC32_MODE | RTC_EMBCK_SEL_OPTION;
        if (!rtc_xosc_write(osc32con)) {
                rtc_info("rtc_xosc_write() failed\n");
                return false;
        }
 
        rtc_read(RTC_CON, &con);
        rtc_read(RTC_OSC32CON, &osc32con);
        rtc_read(RTC_AL_SEC, &sec);
        rtc_info("con = %#x, osc32con = %#x, sec = %#x\n", con, osc32con, sec);
 
        return true;
}
 
/* Initialize RTC related gpio */
bool rtc_gpio_init(void)
{
        u16 con;
 
        /* RTC_32K1V8 clock change from 128k div 4 source to RTC 32k source */
        pwrap_write_field(PMIC_RG_TOP_CKSEL_CON0_SET, 0x1, 0x1, 3);
 
        /* Export 32K clock RTC_32K1V8_1 */
        pwrap_write_field(PMIC_RG_TOP_CKPDN_CON1_CLR, 0x1, 0x1, 1);
 
        /* Export 32K clock RTC_32K2V8 */
        rtc_read(RTC_CON, &con);
        con &= (RTC_CON_LPSTA_RAW | RTC_CON_LPRST | RTC_CON_EOSC32_LPEN
                | RTC_CON_XOSC32_LPEN);
        con |= (RTC_CON_GPEN | RTC_CON_GOE);
        con &= ~RTC_CON_F32KOB;
        rtc_write(RTC_CON, con);
 
        return rtc_write_trigger();
}
 
u16 rtc_get_frequency_meter(u16 val, u16 measure_src, u16 window_size)
{
        u16 bbpu, osc32con;
        u16 fqmtr_busy, fqmtr_data, fqmtr_rst, fqmtr_tcksel;
        struct stopwatch sw;
 
        rtc_read(RTC_BBPU, &bbpu);
        rtc_write(RTC_BBPU, bbpu | RTC_BBPU_KEY | RTC_BBPU_RELOAD);
        if (!rtc_write_trigger()) {
                rtc_info("rtc_write_trigger() failed\n");
                return false;
        }
 
        rtc_read(RTC_OSC32CON, &osc32con);
        if (!rtc_xosc_write((osc32con & ~RTC_XOSCCALI_MASK) |
                            (val & RTC_XOSCCALI_MASK))) {
                rtc_info("rtc_xosc_write() failed\n");
                return false;
        }
 
        /* Enable FQMTR clock */
        pwrap_write_field(PMIC_RG_TOP_CKPDN_CON0_CLR, 1, 1,
                          PMIC_RG_FQMTR_32K_CK_PDN_SHIFT);
        pwrap_write_field(PMIC_RG_TOP_CKPDN_CON0_CLR, 1, 1,
                          PMIC_RG_FQMTR_CK_PDN_SHIFT);
 
        /* FQMTR reset */
        pwrap_write_field(PMIC_RG_FQMTR_RST, 1, 1, PMIC_FQMTR_RST_SHIFT);
        do {
                rtc_read(PMIC_RG_FQMTR_DATA, &fqmtr_data);
                rtc_read(PMIC_RG_FQMTR_CON0, &fqmtr_busy);
        } while (fqmtr_data && (fqmtr_busy & PMIC_FQMTR_CON0_BUSY));
        rtc_read(PMIC_RG_FQMTR_RST, &fqmtr_rst);
        /* FQMTR normal */
        pwrap_write_field(PMIC_RG_FQMTR_RST, 0, 1, PMIC_FQMTR_RST_SHIFT);
 
        /* Set frequency meter window value (0=1X32K(fixed clock)) */
        rtc_write(PMIC_RG_FQMTR_WINSET, window_size);
        /* Enable 26M and set test clock source */
        rtc_write(PMIC_RG_FQMTR_CON0, PMIC_FQMTR_CON0_DCXO26M_EN | measure_src);
        /* Enable 26M -> delay 100us -> enable FQMTR */
        udelay(100);
        rtc_read(PMIC_RG_FQMTR_CON0, &fqmtr_tcksel);
        /* Enable FQMTR */
        rtc_write(PMIC_RG_FQMTR_CON0, fqmtr_tcksel | PMIC_FQMTR_CON0_FQMTR_EN);
        udelay(100);
 
        stopwatch_init_usecs_expire(&sw, FQMTR_TIMEOUT_US);
        /* FQMTR read until ready */
        if (!wait_us(FQMTR_TIMEOUT_US,
                     rtc_read(PMIC_RG_FQMTR_CON0, &fqmtr_busy) == 0 &&
                     !(fqmtr_busy & PMIC_FQMTR_CON0_BUSY))) {
                rtc_info("get frequency time out: %#x\n", fqmtr_busy);
                return false;
        }
 
        /* Read data should be closed to 26M/32k = 794 */
        rtc_read(PMIC_RG_FQMTR_DATA, &fqmtr_data);
 
        rtc_read(PMIC_RG_FQMTR_CON0, &fqmtr_tcksel);
        /* Disable FQMTR */
        rtc_write(PMIC_RG_FQMTR_CON0, fqmtr_tcksel & ~PMIC_FQMTR_CON0_FQMTR_EN);
        /* Disable FQMTR -> delay 100us -> disable 26M */
        udelay(100);
        /* Disable 26M */
        rtc_read(PMIC_RG_FQMTR_CON0, &fqmtr_tcksel);
        rtc_write(PMIC_RG_FQMTR_CON0,
                  fqmtr_tcksel & ~PMIC_FQMTR_CON0_DCXO26M_EN);
        rtc_info("input = %#x, output = %#x\n", val, fqmtr_data);
 
        /* Disable FQMTR clock */
        pwrap_write_field(PMIC_RG_TOP_CKPDN_CON0_SET, 1, 1,
                          PMIC_RG_FQMTR_32K_CK_PDN_SHIFT);
        pwrap_write_field(PMIC_RG_TOP_CKPDN_CON0_SET, 1, 1,
                          PMIC_RG_FQMTR_CK_PDN_SHIFT);
 
        return fqmtr_data;
}
 
/* Low power detect setting */
static bool rtc_lpd_init(void)
{
        u16 con, sec;
 
        /* Set RTC_LPD_OPT */
        rtc_read(RTC_AL_SEC, &sec);
        sec |= RTC_LPD_OPT_F32K_CK_ALIVE;
        rtc_write(RTC_AL_SEC, sec);
        if (!rtc_write_trigger()) {
                rtc_info("rtc_write_trigger() failed\n");
                return false;
        }
 
        /* Initialize XOSC32 to detect 32k clock stop */
        rtc_read(RTC_CON, &con);
        con |= RTC_CON_XOSC32_LPEN;
        if (!rtc_lpen(con))
                return false;
 
        /* Initialize EOSC32 to detect RTC low power */
        rtc_read(RTC_CON, &con);
        con |= RTC_CON_EOSC32_LPEN;
        if (!rtc_lpen(con))
                return false;
 
        rtc_read(RTC_CON, &con);
        con &= ~RTC_CON_XOSC32_LPEN;
        rtc_write(RTC_CON, con);
 
        /* Set RTC_LPD_OPT */
        rtc_read(RTC_AL_SEC, &sec);
        sec &= ~RTC_LPD_OPT_MASK;
        sec |= RTC_LPD_OPT_EOSC_LPD;
        rtc_write(RTC_AL_SEC, sec);
        if (!rtc_write_trigger()) {
                rtc_info("rtc_write_trigger() failed\n");
                return false;
        }
 
        return true;
}
 
static bool rtc_hw_init(void)
{
        u16 bbpu;
 
        rtc_read(RTC_BBPU, &bbpu);
        rtc_write(RTC_BBPU, bbpu | RTC_BBPU_KEY | RTC_BBPU_INIT);
        if (!rtc_write_trigger()) {
                rtc_info("rtc_write_trigger() failed\n");
                return false;
        }
 
        udelay(500);
 
        rtc_read(RTC_BBPU, &bbpu);
        rtc_write(RTC_BBPU, bbpu | RTC_BBPU_KEY | RTC_BBPU_RELOAD);
        if (!rtc_write_trigger()) {
                rtc_info("rtc_write_trigger() failed\n");
                return false;
        }
 
        rtc_read(RTC_BBPU, &bbpu);
        if (bbpu & RTC_BBPU_INIT) {
                rtc_info("timeout\n");
                return false;
        }
 
        return true;
}
 
static void mt6366_dcxo_disable_unused(void)
{
        /* Disable clock buffer XO_CEL */
        rtc_write(PMIC_RG_DCXO_CW00_CLR, 0x0800);
        /* Mask bblpm request and switch off bblpm mode */
        rtc_write(PMIC_RG_DCXO_CW23, 0x0052);
}
 
static void rtc_set_capid(u16 capid)
{
        u16 read_capid;
 
        rtc_write(PMIC_RG_DCXO_CW03, 0xFF00 | capid);
 
        rtc_read(PMIC_RG_DCXO_CW03, &read_capid);
        rtc_info("read back capid: %#x\n", read_capid & 0xFF);
}
 
/* Check RTC Initialization */
int rtc_init(int recover)
{
        int ret;
 
        rtc_info("recovery: %d\n", recover);
 
        /* Write powerkeys to enable RTC functions */
        if (!rtc_powerkey_init()) {
                ret = -RTC_STATUS_POWERKEY_INIT_FAIL;
                goto err;
        }
 
        /* Write interface unlock need to be set after powerkey match */
        if (!rtc_writeif_unlock()) {
                ret = -RTC_STATUS_WRITEIF_UNLOCK_FAIL;
                goto err;
        }
 
        rtc_osc_init();
 
        /* In recovery mode, we need 20ms delay for register setting. */
        if (recover)
                mdelay(20);
 
        if (!rtc_gpio_init()) {
                ret = -RTC_STATUS_GPIO_INIT_FAIL;
                goto err;
        }
 
        if (!rtc_hw_init()) {
                ret = -RTC_STATUS_HW_INIT_FAIL;
                goto err;
        }
 
        if (!rtc_reg_init()) {
                ret = -RTC_STATUS_REG_INIT_FAIL;
                goto err;
        }
 
        if (!rtc_lpd_init()) {
                ret = -RTC_STATUS_LPD_INIT_FAIL;
                goto err;
        }
 
        /*
         * After lpd init, powerkeys need to be written again to enable
         * low power detect function.
         */
        if (!rtc_powerkey_init()) {
                ret = -RTC_STATUS_POWERKEY_INIT_FAIL;
                goto err;
        }
 
        return RTC_STATUS_OK;
err:
        rtc_info("init failed: ret = %d\n", ret);
        return ret;
}
 
/* Enable RTC bbpu */
void rtc_bbpu_power_on(void)
{
        u16 bbpu;
        int ret;
 
        /* Pull powerhold high, control by pmic */
        mt6366_set_power_hold(true);
 
        /* Pull PWRBB high */
        bbpu = RTC_BBPU_KEY | RTC_BBPU_AUTO | RTC_BBPU_RELOAD | RTC_BBPU_PWREN;
        rtc_write(RTC_BBPU, bbpu);
        ret = rtc_write_trigger();
        rtc_info("rtc_write_trigger = %d\n", ret);
 
        rtc_read(RTC_BBPU, &bbpu);
        rtc_info("done BBPU = %#x\n", bbpu);
}
 
static void dcxo_init(void)
{
        /* Buffer setting */
        rtc_write(PMIC_RG_DCXO_CW15, 0xA2AA);
        rtc_write(PMIC_RG_DCXO_CW13, 0x98E9);
        rtc_write(PMIC_RG_DCXO_CW16, 0x9855);
 
        /* 26M enable control */
        /* Enable clock buffer XO_SOC, XO_CEL */
        rtc_write(PMIC_RG_DCXO_CW00, 0x4805);
        rtc_write(PMIC_RG_DCXO_CW11, 0x8000);
 
        /* Load thermal coefficient */
        rtc_write(PMIC_RG_TOP_TMA_KEY, 0x9CA7);
        rtc_write(PMIC_RG_DCXO_CW21, 0x12A7);
        rtc_write(PMIC_RG_DCXO_ELR0, 0xD004);
        rtc_write(PMIC_RG_TOP_TMA_KEY, 0x0000);
 
        /* Adjust OSC FPM setting */
        rtc_write(PMIC_RG_DCXO_CW07, 0x8FFE);
 
        /* Re-calibrate OSC current */
        rtc_write(PMIC_RG_DCXO_CW09, 0x008F);
        udelay(100);
        rtc_write(PMIC_RG_DCXO_CW09, 0x408F);
        mdelay(5);
 
        rtc_set_capid(MT8186_RTC_DXCO_CAPID);
 
        mt6366_dcxo_disable_unused();
}
 
/* Initialize rtc boot flow */
void rtc_boot(void)
{
        /* DCXO clock initialized settings */
        dcxo_init();
 
        /* DCXO 32k initialized settings */
        pwrap_write_field(PMIC_RG_DCXO_CW02, 0xF, 0xF, 0);
        pwrap_write_field(PMIC_RG_SCK_TOP_CON0, 0x1, 0x1, 0);
 
        /* Use DCXO 32K clock */
        if (!rtc_enable_dcxo())
                rtc_info("rtc_enable_dcxo() failed\n");
 
        rtc_boot_common();
        rtc_bbpu_power_on();
}