feat(st-ddr): add STM32MP2 driver

Add driver to support DDR on STM32MP2 platform. It drives the DDR PHY
and its firmware, as well as the DDR controller.

Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>
Signed-off-by: Maxime Méré <maxime.mere@foss.st.com>
Change-Id: I93de2db1b9378d5654e76b3bf6f3407d80bc4ca5
diff --git a/drivers/st/ddr/stm32mp2_ddr_helpers.c b/drivers/st/ddr/stm32mp2_ddr_helpers.c
index e6be9dd..a2a4082 100644
--- a/drivers/st/ddr/stm32mp2_ddr_helpers.c
+++ b/drivers/st/ddr/stm32mp2_ddr_helpers.c
@@ -4,12 +4,524 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <errno.h>
+
+#include <arch_helpers.h>
+#include <common/debug.h>
+
+#include <drivers/delay_timer.h>
+#include <drivers/st/stm32mp2_ddr.h>
+#include <drivers/st/stm32mp2_ddr_helpers.h>
+#include <drivers/st/stm32mp2_ddr_regs.h>
+#include <drivers/st/stm32mp_ddr.h>
+
 #include <lib/mmio.h>
 
 #include <platform_def.h>
 
+/* HW idle period (unit: Multiples of 32 DFI clock cycles) */
+#define HW_IDLE_PERIOD			0x3U
+
+static enum stm32mp2_ddr_sr_mode saved_ddr_sr_mode;
+
+#pragma weak stm32_ddrdbg_get_base
+uintptr_t stm32_ddrdbg_get_base(void)
+{
+	return 0U;
+}
+
+static void set_qd1_qd3_update_conditions(struct stm32mp_ddrctl *ctl)
+{
+	mmio_setbits_32((uintptr_t)&ctl->dbg1, DDRCTRL_DBG1_DIS_DQ);
+
+	stm32mp_ddr_set_qd3_update_conditions(ctl);
+}
+
+static void unset_qd1_qd3_update_conditions(struct stm32mp_ddrctl *ctl)
+{
+	stm32mp_ddr_unset_qd3_update_conditions(ctl);
+
+	mmio_clrbits_32((uintptr_t)&ctl->dbg1, DDRCTRL_DBG1_DIS_DQ);
+}
+
+static void wait_dfi_init_complete(struct stm32mp_ddrctl *ctl)
+{
+	uint64_t timeout;
+	uint32_t dfistat;
+
+	timeout = timeout_init_us(DDR_TIMEOUT_US_1S);
+	do {
+		dfistat = mmio_read_32((uintptr_t)&ctl->dfistat);
+		VERBOSE("[0x%lx] dfistat = 0x%x ", (uintptr_t)&ctl->dfistat, dfistat);
+
+		if (timeout_elapsed(timeout)) {
+			panic();
+		}
+	} while ((dfistat & DDRCTRL_DFISTAT_DFI_INIT_COMPLETE) == 0U);
+
+	VERBOSE("[0x%lx] dfistat = 0x%x\n", (uintptr_t)&ctl->dfistat, dfistat);
+}
+
+static void disable_dfi_low_power_interface(struct stm32mp_ddrctl *ctl)
+{
+	uint64_t timeout;
+	uint32_t dfistat;
+	uint32_t stat;
+
+	mmio_clrbits_32((uintptr_t)&ctl->dfilpcfg0, DDRCTRL_DFILPCFG0_DFI_LP_EN_SR);
+
+	timeout = timeout_init_us(DDR_TIMEOUT_US_1S);
+	do {
+		dfistat = mmio_read_32((uintptr_t)&ctl->dfistat);
+		stat = mmio_read_32((uintptr_t)&ctl->stat);
+		VERBOSE("[0x%lx] dfistat = 0x%x ", (uintptr_t)&ctl->dfistat, dfistat);
+		VERBOSE("[0x%lx] stat = 0x%x ", (uintptr_t)&ctl->stat, stat);
+
+		if (timeout_elapsed(timeout)) {
+			panic();
+		}
+	} while (((dfistat & DDRCTRL_DFISTAT_DFI_LP_ACK) != 0U) ||
+		 ((stat & DDRCTRL_STAT_OPERATING_MODE_MASK) == DDRCTRL_STAT_OPERATING_MODE_SR));
+
+	VERBOSE("[0x%lx] dfistat = 0x%x\n", (uintptr_t)&ctl->dfistat, dfistat);
+	VERBOSE("[0x%lx] stat = 0x%x\n", (uintptr_t)&ctl->stat, stat);
+}
+
+void ddr_activate_controller(struct stm32mp_ddrctl *ctl, bool sr_entry)
+{
+	/*
+	 * Manage quasi-dynamic registers modification
+	 * dfimisc.dfi_frequency : Group 1
+	 * dfimisc.dfi_init_complete_en and dfimisc.dfi_init_start : Group 3
+	 */
+	set_qd1_qd3_update_conditions(ctl);
+
+	if (sr_entry) {
+		mmio_setbits_32((uintptr_t)&ctl->dfimisc, DDRCTRL_DFIMISC_DFI_FREQUENCY);
+	} else {
+		mmio_clrbits_32((uintptr_t)&ctl->dfimisc, DDRCTRL_DFIMISC_DFI_FREQUENCY);
+	}
+
+	mmio_setbits_32((uintptr_t)&ctl->dfimisc, DDRCTRL_DFIMISC_DFI_INIT_START);
+	mmio_clrbits_32((uintptr_t)&ctl->dfimisc, DDRCTRL_DFIMISC_DFI_INIT_START);
+
+	wait_dfi_init_complete(ctl);
+
+	udelay(DDR_DELAY_1US);
+
+	if (sr_entry) {
+		mmio_clrbits_32((uintptr_t)&ctl->dfimisc, DDRCTRL_DFIMISC_DFI_INIT_COMPLETE_EN);
+	} else {
+		mmio_setbits_32((uintptr_t)&ctl->dfimisc, DDRCTRL_DFIMISC_DFI_INIT_COMPLETE_EN);
+	}
+
+	udelay(DDR_DELAY_1US);
+
+	unset_qd1_qd3_update_conditions(ctl);
+}
+
+#if STM32MP_LPDDR4_TYPE
+static void disable_phy_ddc(void)
+{
+	/* Enable APB access to internal CSR registers */
+	mmio_write_32(stm32mp_ddrphyc_base() + DDRPHY_APBONLY0_MICROCONTMUXSEL, 0U);
+	mmio_write_32(stm32mp_ddrphyc_base() + DDRPHY_DRTUB0_UCCLKHCLKENABLES,
+		      DDRPHY_DRTUB0_UCCLKHCLKENABLES_UCCLKEN |
+		      DDRPHY_DRTUB0_UCCLKHCLKENABLES_HCLKEN);
+
+	/* Disable DRAM drift compensation */
+	mmio_write_32(stm32mp_ddrphyc_base() + DDRPHY_INITENG0_P0_SEQ0BDISABLEFLAG6, 0xFFFFU);
+
+	/* Disable APB access to internal CSR registers */
+	mmio_write_32(stm32mp_ddrphyc_base() + DDRPHY_DRTUB0_UCCLKHCLKENABLES,
+		      DDRPHY_DRTUB0_UCCLKHCLKENABLES_HCLKEN);
+	mmio_write_32(stm32mp_ddrphyc_base() + DDRPHY_APBONLY0_MICROCONTMUXSEL,
+		      DDRPHY_APBONLY0_MICROCONTMUXSEL_MICROCONTMUXSEL);
+}
+#endif /* STM32MP_LPDDR4_TYPE */
+
+void ddr_wait_lp3_mode(bool sr_entry)
+{
+	uint64_t timeout;
+	bool repeat_loop = false;
+
+	/* Enable APB access to internal CSR registers */
+	mmio_write_32(stm32mp_ddrphyc_base() + DDRPHY_APBONLY0_MICROCONTMUXSEL, 0U);
+	mmio_write_32(stm32mp_ddrphyc_base() + DDRPHY_DRTUB0_UCCLKHCLKENABLES,
+		      DDRPHY_DRTUB0_UCCLKHCLKENABLES_UCCLKEN |
+		      DDRPHY_DRTUB0_UCCLKHCLKENABLES_HCLKEN);
+
+	timeout = timeout_init_us(DDR_TIMEOUT_US_1S);
+	do {
+		uint16_t phyinlpx = mmio_read_32(stm32mp_ddrphyc_base() +
+						 DDRPHY_INITENG0_P0_PHYINLPX);
+
+		if (timeout_elapsed(timeout)) {
+			panic();
+		}
+
+		if (sr_entry) {
+			repeat_loop = (phyinlpx & DDRPHY_INITENG0_P0_PHYINLPX_PHYINLP3) == 0U;
+		} else {
+			repeat_loop = (phyinlpx & DDRPHY_INITENG0_P0_PHYINLPX_PHYINLP3) != 0U;
+		}
+	} while (repeat_loop);
+
+	/* Disable APB access to internal CSR registers */
+#if STM32MP_DDR3_TYPE || STM32MP_DDR4_TYPE
+	mmio_write_32(stm32mp_ddrphyc_base() + DDRPHY_DRTUB0_UCCLKHCLKENABLES, 0U);
+#else /* STM32MP_LPDDR4_TYPE */
+	mmio_write_32(stm32mp_ddrphyc_base() + DDRPHY_DRTUB0_UCCLKHCLKENABLES,
+		      DDRPHY_DRTUB0_UCCLKHCLKENABLES_HCLKEN);
+#endif /* STM32MP_DDR3_TYPE || STM32MP_DDR4_TYPE */
+	mmio_write_32(stm32mp_ddrphyc_base() + DDRPHY_APBONLY0_MICROCONTMUXSEL,
+		      DDRPHY_APBONLY0_MICROCONTMUXSEL_MICROCONTMUXSEL);
+}
+
+static int sr_loop(bool is_entry)
+{
+	uint32_t type;
+	uint32_t state __maybe_unused;
+	uint64_t timeout = timeout_init_us(DDR_TIMEOUT_US_1S);
+	bool repeat_loop = false;
+
+	/*
+	 * Wait for DDRCTRL to be out of or back to "normal/mission mode".
+	 * Consider also SRPD mode for LPDDR4 only.
+	 */
+	do {
+		type = mmio_read_32(stm32mp_ddrctrl_base() + DDRCTRL_STAT) &
+		       DDRCTRL_STAT_SELFREF_TYPE_MASK;
+#if STM32MP_LPDDR4_TYPE
+		state = mmio_read_32(stm32mp_ddrctrl_base() + DDRCTRL_STAT) &
+		       DDRCTRL_STAT_SELFREF_STATE_MASK;
+#endif /* STM32MP_LPDDR4_TYPE */
+
+		if (timeout_elapsed(timeout)) {
+			return -ETIMEDOUT;
+		}
+
+		if (is_entry) {
+#if STM32MP_LPDDR4_TYPE
+			repeat_loop = (type == 0x0U) || (state != DDRCTRL_STAT_SELFREF_STATE_SRPD);
+#else /* !STM32MP_LPDDR4_TYPE */
+			repeat_loop = (type == 0x0U);
+#endif /* STM32MP_LPDDR4_TYPE */
+		} else {
+#if STM32MP_LPDDR4_TYPE
+			repeat_loop = (type != 0x0U) || (state != 0x0U);
+#else /* !STM32MP_LPDDR4_TYPE */
+			repeat_loop = (type != 0x0U);
+#endif /* STM32MP_LPDDR4_TYPE */
+		}
+	} while (repeat_loop);
+
+	return 0;
+}
+
+static int sr_entry_loop(void)
+{
+	return sr_loop(true);
+}
+
+int ddr_sr_exit_loop(void)
+{
+	return sr_loop(false);
+}
+
+static int sr_ssr_set(void)
+{
+	uintptr_t ddrctrl_base = stm32mp_ddrctrl_base();
+
+	/*
+	 * Disable Clock disable with LP modes
+	 * (used in RUN mode for LPDDR2 with specific timing).
+	 */
+	mmio_clrbits_32(ddrctrl_base + DDRCTRL_PWRCTL, DDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE);
+
+	/* Disable automatic Self-Refresh mode */
+	mmio_clrbits_32(ddrctrl_base + DDRCTRL_PWRCTL, DDRCTRL_PWRCTL_SELFREF_EN);
+
+	mmio_write_32(stm32_ddrdbg_get_base() + DDRDBG_LP_DISABLE,
+		      DDRDBG_LP_DISABLE_LPI_XPI_DISABLE | DDRDBG_LP_DISABLE_LPI_DDRC_DISABLE);
+
+	return 0;
+}
+
+static int sr_ssr_entry(bool standby)
+{
+	uintptr_t ddrctrl_base = stm32mp_ddrctrl_base();
+	uintptr_t rcc_base = stm32mp_rcc_base();
+
+	if (stm32mp_ddr_disable_axi_port((struct stm32mp_ddrctl *)ddrctrl_base) != 0) {
+		panic();
+	}
+
+#if STM32MP_LPDDR4_TYPE
+	if (standby) {
+		/* Disable DRAM drift compensation */
+		disable_phy_ddc();
+	}
+#endif /* STM32MP_LPDDR4_TYPE */
+
+	disable_dfi_low_power_interface((struct stm32mp_ddrctl *)ddrctrl_base);
+
+	/* SW self refresh entry prequested */
+	mmio_setbits_32(ddrctrl_base + DDRCTRL_PWRCTL, DDRCTRL_PWRCTL_SELFREF_SW);
+#if STM32MP_LPDDR4_TYPE
+	mmio_clrbits_32(ddrctrl_base + DDRCTRL_PWRCTL, DDRCTRL_PWRCTL_STAY_IN_SELFREF);
+#endif /* STM32MP_LPDDR4_TYPE */
+
+	if (sr_entry_loop() != 0) {
+		return -1;
+	}
+
+	ddr_activate_controller((struct stm32mp_ddrctl *)ddrctrl_base, true);
+
+	/* Poll on ddrphy_initeng0_phyinlpx.phyinlp3 = 1 */
+	ddr_wait_lp3_mode(true);
+
+	if (standby) {
+		mmio_clrbits_32(stm32mp_pwr_base() + PWR_CR11, PWR_CR11_DDRRETDIS);
+	}
+
+	mmio_clrsetbits_32(rcc_base + RCC_DDRCPCFGR, RCC_DDRCPCFGR_DDRCPLPEN,
+			   RCC_DDRCPCFGR_DDRCPEN);
+	mmio_setbits_32(rcc_base + RCC_DDRPHYCCFGR, RCC_DDRPHYCCFGR_DDRPHYCEN);
+	mmio_setbits_32(rcc_base + RCC_DDRITFCFGR, RCC_DDRITFCFGR_DDRPHYDLP);
+
+	return 0;
+}
+
+static int sr_ssr_exit(void)
+{
+	uintptr_t ddrctrl_base = stm32mp_ddrctrl_base();
+	uintptr_t rcc_base = stm32mp_rcc_base();
+
+	mmio_setbits_32(rcc_base + RCC_DDRCPCFGR,
+			RCC_DDRCPCFGR_DDRCPLPEN | RCC_DDRCPCFGR_DDRCPEN);
+	mmio_clrbits_32(rcc_base + RCC_DDRITFCFGR, RCC_DDRITFCFGR_DDRPHYDLP);
+	mmio_setbits_32(rcc_base + RCC_DDRPHYCCFGR, RCC_DDRPHYCCFGR_DDRPHYCEN);
+
+	udelay(DDR_DELAY_1US);
+
+	ddr_activate_controller((struct stm32mp_ddrctl *)ddrctrl_base, false);
+
+	/* Poll on ddrphy_initeng0_phyinlpx.phyinlp3 = 0 */
+	ddr_wait_lp3_mode(false);
+
+	/* SW self refresh exit prequested */
+	mmio_clrbits_32(ddrctrl_base + DDRCTRL_PWRCTL, DDRCTRL_PWRCTL_SELFREF_SW);
+
+	if (ddr_sr_exit_loop() != 0) {
+		return -1;
+	}
+
+	/* Re-enable DFI low-power interface */
+	mmio_setbits_32(ddrctrl_base + DDRCTRL_DFILPCFG0, DDRCTRL_DFILPCFG0_DFI_LP_EN_SR);
+
+	stm32mp_ddr_enable_axi_port((struct stm32mp_ddrctl *)ddrctrl_base);
+
+	return 0;
+}
+
+static int sr_hsr_set(void)
+{
+	uintptr_t ddrctrl_base = stm32mp_ddrctrl_base();
+
+	mmio_clrsetbits_32(stm32mp_rcc_base() + RCC_DDRITFCFGR,
+			   RCC_DDRITFCFGR_DDRCKMOD_MASK, RCC_DDRITFCFGR_DDRCKMOD_HSR);
+
+	/*
+	 * manage quasi-dynamic registers modification
+	 * hwlpctl.hw_lp_en : Group 2
+	 */
+	if (stm32mp_ddr_sw_selfref_entry((struct stm32mp_ddrctl *)ddrctrl_base) != 0) {
+		panic();
+	}
+	stm32mp_ddr_start_sw_done((struct stm32mp_ddrctl *)ddrctrl_base);
+
+	mmio_write_32(ddrctrl_base + DDRCTRL_HWLPCTL,
+		      DDRCTRL_HWLPCTL_HW_LP_EN | DDRCTRL_HWLPCTL_HW_LP_EXIT_IDLE_EN |
+		      (HW_IDLE_PERIOD << DDRCTRL_HWLPCTL_HW_LP_IDLE_X32_SHIFT));
+
+	stm32mp_ddr_wait_sw_done_ack((struct stm32mp_ddrctl *)ddrctrl_base);
+	stm32mp_ddr_sw_selfref_exit((struct stm32mp_ddrctl *)ddrctrl_base);
+
+	return 0;
+}
+
+static int sr_hsr_entry(void)
+{
+	mmio_write_32(stm32mp_rcc_base() + RCC_DDRCPCFGR, RCC_DDRCPCFGR_DDRCPLPEN);
+
+	return sr_entry_loop(); /* read_data should be equal to 0x223 */
+}
+
+static int sr_hsr_exit(void)
+{
+	mmio_write_32(stm32mp_rcc_base() + RCC_DDRCPCFGR,
+		      RCC_DDRCPCFGR_DDRCPLPEN | RCC_DDRCPCFGR_DDRCPEN);
+
+	/* TODO: check if ddr_sr_exit_loop() is needed here */
+
+	return 0;
+}
+
+static int sr_asr_set(void)
+{
+	mmio_write_32(stm32_ddrdbg_get_base() + DDRDBG_LP_DISABLE, 0U);
+
+	return 0;
+}
+
+static int sr_asr_entry(void)
+{
+	/*
+	 * Automatically enter into self refresh when there is no ddr traffic
+	 * for the delay programmed into SYSCONF_DDRC_AUTO_SR_DELAY register.
+	 * Default value is 0x20 (unit: Multiples of 32 DFI clock cycles).
+	 */
+	return sr_entry_loop();
+}
+
+static int sr_asr_exit(void)
+{
+	return ddr_sr_exit_loop();
+}
+
+uint32_t ddr_get_io_calibration_val(void)
+{
+	/* TODO create related service */
+
+	return 0U;
+}
+
+int ddr_sr_entry(bool standby)
+{
+	int ret = -EINVAL;
+
+	switch (saved_ddr_sr_mode) {
+	case DDR_SSR_MODE:
+		ret = sr_ssr_entry(standby);
+		break;
+	case DDR_HSR_MODE:
+		ret = sr_hsr_entry();
+		break;
+	case DDR_ASR_MODE:
+		ret = sr_asr_entry();
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+int ddr_sr_exit(void)
+{
+	int ret = -EINVAL;
+
+	switch (saved_ddr_sr_mode) {
+	case DDR_SSR_MODE:
+		ret = sr_ssr_exit();
+		break;
+	case DDR_HSR_MODE:
+		ret = sr_hsr_exit();
+		break;
+	case DDR_ASR_MODE:
+		ret = sr_asr_exit();
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+enum stm32mp2_ddr_sr_mode ddr_read_sr_mode(void)
+{
+	uint32_t pwrctl = mmio_read_32(stm32mp_ddrctrl_base() + DDRCTRL_PWRCTL);
+	enum stm32mp2_ddr_sr_mode mode = DDR_SR_MODE_INVALID;
+
+	switch (pwrctl & (DDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE |
+			  DDRCTRL_PWRCTL_SELFREF_EN)) {
+	case 0U:
+		mode = DDR_SSR_MODE;
+		break;
+	case DDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE:
+		mode = DDR_HSR_MODE;
+		break;
+	case DDRCTRL_PWRCTL_EN_DFI_DRAM_CLK_DISABLE | DDRCTRL_PWRCTL_SELFREF_EN:
+		mode = DDR_ASR_MODE;
+		break;
+	default:
+		break;
+	}
+
+	return mode;
+}
+
+void ddr_set_sr_mode(enum stm32mp2_ddr_sr_mode mode)
+{
+	int ret = -EINVAL;
+
+	if (mode == saved_ddr_sr_mode) {
+		return;
+	}
+
+	switch (mode) {
+	case DDR_SSR_MODE:
+		ret = sr_ssr_set();
+		break;
+	case DDR_HSR_MODE:
+		ret = sr_hsr_set();
+		break;
+	case DDR_ASR_MODE:
+		ret = sr_asr_set();
+		break;
+	default:
+		break;
+	}
+
+	if (ret != 0) {
+		ERROR("Unknown Self Refresh mode\n");
+		panic();
+	}
+
+	saved_ddr_sr_mode = mode;
+}
+
+void ddr_save_sr_mode(void)
+{
+	saved_ddr_sr_mode = ddr_read_sr_mode();
+}
+
+void ddr_restore_sr_mode(void)
+{
+	ddr_set_sr_mode(saved_ddr_sr_mode);
+}
+
 void ddr_sub_system_clk_init(void)
 {
 	mmio_write_32(stm32mp_rcc_base() + RCC_DDRCPCFGR,
 		      RCC_DDRCPCFGR_DDRCPEN | RCC_DDRCPCFGR_DDRCPLPEN);
 }
+
+void ddr_sub_system_clk_off(void)
+{
+	uintptr_t rcc_base = stm32mp_rcc_base();
+
+	/* Clear DDR IO retention */
+	mmio_clrbits_32(stm32mp_pwr_base() + PWR_CR11, PWR_CR11_DDRRETDIS);
+
+	/* Reset DDR sub system */
+	mmio_write_32(rcc_base + RCC_DDRCPCFGR, RCC_DDRCPCFGR_DDRCPRST);
+	mmio_write_32(rcc_base + RCC_DDRITFCFGR, RCC_DDRITFCFGR_DDRRST);
+	mmio_write_32(rcc_base + RCC_DDRPHYCAPBCFGR, RCC_DDRPHYCAPBCFGR_DDRPHYCAPBRST);
+	mmio_write_32(rcc_base + RCC_DDRCAPBCFGR, RCC_DDRCAPBCFGR_DDRCAPBRST);
+
+	/* Deactivate clocks and PLL2 */
+	mmio_clrbits_32(rcc_base + RCC_DDRPHYCCFGR, RCC_DDRPHYCCFGR_DDRPHYCEN);
+	mmio_clrbits_32(rcc_base + RCC_PLL2CFGR1, RCC_PLL2CFGR1_PLLEN);
+}