zephyr/drivers/memc/memc_mcux_flexspi.c

/*
 * Copyright 2020-2023 NXP
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#define DT_DRV_COMPAT	nxp_imx_flexspi

#include <zephyr/logging/log.h>
#include <zephyr/sys/util.h>
#include <zephyr/drivers/pinctrl.h>
#include <zephyr/drivers/clock_control.h>
#include <zephyr/pm/device.h>
#include <soc.h>

#include "memc_mcux_flexspi.h"


/*
 * NOTE: If CONFIG_FLASH_MCUX_FLEXSPI_XIP is selected, Any external functions
 * called while interacting with the flexspi MUST be relocated to SRAM or ITCM
 * at runtime, so that the chip does not access the flexspi to read program
 * instructions while it is being written to
 */
#if defined(CONFIG_FLASH_MCUX_FLEXSPI_XIP) && (CONFIG_MEMC_LOG_LEVEL > 0)
#warning "Enabling memc driver logging and XIP mode simultaneously can cause \
	read-while-write hazards. This configuration is not recommended."
#endif

#define FLEXSPI_MAX_LUT 64U

LOG_MODULE_REGISTER(memc_flexspi, CONFIG_MEMC_LOG_LEVEL);

struct memc_flexspi_buf_cfg {
	uint16_t prefetch;
	uint16_t priority;
	uint16_t master_id;
	uint16_t buf_size;
} __packed;

/* Structure tracking LUT offset and usage per each port */
struct port_lut {
	uint8_t lut_offset;
	uint8_t lut_used;
};

/* flexspi device data should be stored in RAM to avoid read-while-write hazards */
struct memc_flexspi_data {
	FLEXSPI_Type *base;
	uint8_t *ahb_base;
	bool xip;
	bool ahb_bufferable;
	bool ahb_cacheable;
	bool ahb_prefetch;
	bool ahb_read_addr_opt;
	bool combination_mode;
	bool sck_differential_clock;
	flexspi_read_sample_clock_t rx_sample_clock;
	const struct pinctrl_dev_config *pincfg;
	size_t size[kFLEXSPI_PortCount];
	struct port_lut port_luts[kFLEXSPI_PortCount];
	struct memc_flexspi_buf_cfg *buf_cfg;
	uint8_t buf_cfg_cnt;
	const struct device *clock_dev;
	clock_control_subsys_t clock_subsys;
};

void memc_flexspi_wait_bus_idle(const struct device *dev)
{
	struct memc_flexspi_data *data = dev->data;

	while (false == FLEXSPI_GetBusIdleStatus(data->base)) {
	}
}

bool memc_flexspi_is_running_xip(const struct device *dev)
{
	struct memc_flexspi_data *data = dev->data;

	return data->xip;
}

int memc_flexspi_update_clock(const struct device *dev,
		flexspi_device_config_t *device_config,
		flexspi_port_t port, uint32_t freq_hz)
{
	struct memc_flexspi_data *data = dev->data;
	uint32_t rate;
	uint32_t key;
	int ret;

	/* To reclock the FlexSPI, we should:
	 * - disable the module
	 * - set the new clock
	 * - reenable the module
	 * - reset the module
	 * We CANNOT XIP at any point during this process
	 */
	key = irq_lock();
	memc_flexspi_wait_bus_idle(dev);

	ret = clock_control_set_rate(data->clock_dev, data->clock_subsys,
				(clock_control_subsys_rate_t)freq_hz);
	if (ret < 0) {
		irq_unlock(key);
		return ret;
	}

	/*
	 * We need to update the DLL value before we call clock_control_get_rate,
	 * because this will cause XIP (flash reads) to occur. Although the
	 * true flash clock is not known, assume the set_rate function programmed
	 * a value close to what we requested.
	 */
	device_config->flexspiRootClk = freq_hz;
	FLEXSPI_UpdateDllValue(data->base, device_config, port);
	memc_flexspi_reset(dev);

	memc_flexspi_wait_bus_idle(dev);
	ret = clock_control_get_rate(data->clock_dev, data->clock_subsys, &rate);
	if (ret < 0) {
		irq_unlock(key);
		return ret;
	}


	device_config->flexspiRootClk = rate;
	FLEXSPI_UpdateDllValue(data->base, device_config, port);

	memc_flexspi_reset(dev);

	irq_unlock(key);

	return 0;
}

int memc_flexspi_set_device_config(const struct device *dev,
		const flexspi_device_config_t *device_config,
		const uint32_t *lut_array,
		uint8_t lut_count,
		flexspi_port_t port)
{
	flexspi_device_config_t tmp_config;
	uint32_t tmp_lut[FLEXSPI_MAX_LUT];
	struct memc_flexspi_data *data = dev->data;
	const uint32_t *lut_ptr = lut_array;
	uint8_t lut_used = 0U;
	unsigned int key = 0;

	if (port >= kFLEXSPI_PortCount) {
		LOG_ERR("Invalid port number");
		return -EINVAL;
	}

	if (data->port_luts[port].lut_used < lut_count) {
		/* We cannot reuse the existing LUT slot,
		 * Check if the LUT table will fit into the remaining LUT slots
		 */
		for (uint8_t i = 0; i < kFLEXSPI_PortCount; i++) {
			lut_used += data->port_luts[i].lut_used;
		}

		if ((lut_used + lut_count) > FLEXSPI_MAX_LUT) {
			return -ENOBUFS;
		}
	}

	data->size[port] = device_config->flashSize * KB(1);

	if (memc_flexspi_is_running_xip(dev)) {
		/* We need to avoid flash access while configuring the FlexSPI.
		 * To do this, we will copy the LUT array into stack-allocated
		 * temporary memory
		 */
		memcpy(tmp_lut, lut_array, lut_count * MEMC_FLEXSPI_CMD_SIZE);
		lut_ptr = tmp_lut;
	}

	memcpy(&tmp_config, device_config, sizeof(tmp_config));
	/* Update FlexSPI AWRSEQID and ARDSEQID values based on where the LUT
	 * array will actually be loaded.
	 */
	if (data->port_luts[port].lut_used < lut_count) {
		/* Update lut offset with new value */
		data->port_luts[port].lut_offset = lut_used;
	}
	data->port_luts[port].lut_used = lut_count;
	tmp_config.ARDSeqIndex += data->port_luts[port].lut_offset;
	tmp_config.AWRSeqIndex += data->port_luts[port].lut_offset;

	/* Lock IRQs before reconfiguring FlexSPI, to prevent XIP */
	key = irq_lock();

	FLEXSPI_SetFlashConfig(data->base, &tmp_config, port);
	FLEXSPI_UpdateLUT(data->base, data->port_luts[port].lut_offset,
			  lut_ptr, lut_count);
	irq_unlock(key);

	return 0;
}

int memc_flexspi_reset(const struct device *dev)
{
	struct memc_flexspi_data *data = dev->data;

	FLEXSPI_SoftwareReset(data->base);

	return 0;
}

int memc_flexspi_transfer(const struct device *dev,
		flexspi_transfer_t *transfer)
{
	struct memc_flexspi_data *data = dev->data;
	status_t status;

	/* Adjust transfer LUT index based on port */
	transfer->seqIndex += data->port_luts[transfer->port].lut_offset;
	status = FLEXSPI_TransferBlocking(data->base, transfer);

	if (status != kStatus_Success) {
		LOG_ERR("Transfer error: %d", status);
		return -EIO;
	}

	return 0;
}

void *memc_flexspi_get_ahb_address(const struct device *dev,
		flexspi_port_t port, off_t offset)
{
	struct memc_flexspi_data *data = dev->data;
	int i;

	if (port >= kFLEXSPI_PortCount) {
		LOG_ERR("Invalid port number: %u", port);
		return NULL;
	}

	for (i = 0; i < port; i++) {
		offset += data->size[i];
	}

	return data->ahb_base + offset;
}

static int memc_flexspi_init(const struct device *dev)
{
	struct memc_flexspi_data *data = dev->data;
	flexspi_config_t flexspi_config;

	/* we should not configure the device we are running on */
	if (memc_flexspi_is_running_xip(dev)) {
		LOG_DBG("XIP active on %s, skipping init", dev->name);
		return 0;
	}

	/*
	 * SOCs such as the RT1064 and RT1024 have internal flash, and no pinmux
	 * settings, continue if no pinctrl state found.
	 */
	int ret;

	ret = pinctrl_apply_state(data->pincfg, PINCTRL_STATE_DEFAULT);
	if (ret < 0 && ret != -ENOENT) {
		return ret;
	}

	FLEXSPI_GetDefaultConfig(&flexspi_config);

	flexspi_config.ahbConfig.enableAHBBufferable = data->ahb_bufferable;
	flexspi_config.ahbConfig.enableAHBCachable = data->ahb_cacheable;
	flexspi_config.ahbConfig.enableAHBPrefetch = data->ahb_prefetch;
	flexspi_config.ahbConfig.enableReadAddressOpt = data->ahb_read_addr_opt;
#if !(defined(FSL_FEATURE_FLEXSPI_HAS_NO_MCR0_COMBINATIONEN) && \
	FSL_FEATURE_FLEXSPI_HAS_NO_MCR0_COMBINATIONEN)
	flexspi_config.enableCombination = data->combination_mode;
#endif

#if !(defined(FSL_FEATURE_FLEXSPI_HAS_NO_MCR2_SCKBDIFFOPT) && \
	FSL_FEATURE_FLEXSPI_HAS_NO_MCR2_SCKBDIFFOPT)
	flexspi_config.enableSckBDiffOpt = data->sck_differential_clock;
#endif
	flexspi_config.rxSampleClock = data->rx_sample_clock;

	/* Configure AHB RX buffers, if any configuration settings are present */
	__ASSERT(data->buf_cfg_cnt < FSL_FEATURE_FLEXSPI_AHB_BUFFER_COUNT,
		"Maximum RX buffer configuration count exceeded");
	for (uint8_t i = 0; i < data->buf_cfg_cnt; i++) {
		/* Should AHB prefetch up to buffer size? */
		flexspi_config.ahbConfig.buffer[i].enablePrefetch = data->buf_cfg[i].prefetch;
		/* AHB access priority (used for suspending control of AHB prefetching )*/
		flexspi_config.ahbConfig.buffer[i].priority = data->buf_cfg[i].priority;
		/* AHB master index, SOC specific */
		flexspi_config.ahbConfig.buffer[i].masterIndex = data->buf_cfg[i].master_id;
		/* RX buffer allocation (total available buffer space is instance/SOC specific) */
		flexspi_config.ahbConfig.buffer[i].bufferSize = data->buf_cfg[i].buf_size;
	}

	FLEXSPI_Init(data->base, &flexspi_config);

	return 0;
}

#ifdef CONFIG_PM_DEVICE
static int memc_flexspi_pm_action(const struct device *dev, enum pm_device_action action)
{
	struct memc_flexspi_data *data = dev->data;
	int ret;

	switch (action) {
	case PM_DEVICE_ACTION_RESUME:
		ret = pinctrl_apply_state(data->pincfg, PINCTRL_STATE_DEFAULT);
		if (ret < 0 && ret != -ENOENT) {
			return ret;
		}
		break;
	case PM_DEVICE_ACTION_SUSPEND:
		ret = pinctrl_apply_state(data->pincfg, PINCTRL_STATE_SLEEP);
		if (ret < 0 && ret != -ENOENT) {
			return ret;
		}
		break;
	default:
		return -ENOTSUP;
	}

	return 0;
}
#endif

#if defined(CONFIG_XIP) && defined(CONFIG_FLASH_MCUX_FLEXSPI_XIP)
/* Checks if image flash base address is in the FlexSPI AHB base region */
#define MEMC_FLEXSPI_CFG_XIP(node_id)						\
	((CONFIG_FLASH_BASE_ADDRESS) >= DT_REG_ADDR_BY_IDX(node_id, 1)) &&	\
	((CONFIG_FLASH_BASE_ADDRESS) < (DT_REG_ADDR_BY_IDX(node_id, 1) +	\
					DT_REG_SIZE_BY_IDX(node_id, 1)))

#else
#define MEMC_FLEXSPI_CFG_XIP(node_id) false
#endif

#define MEMC_FLEXSPI(n)							\
	PINCTRL_DT_INST_DEFINE(n);					\
	static uint16_t  buf_cfg_##n[] =				\
		DT_INST_PROP_OR(n, rx_buffer_config, {0});		\
									\
	static struct memc_flexspi_data					\
		memc_flexspi_data_##n = {				\
		.base = (FLEXSPI_Type *) DT_INST_REG_ADDR(n),		\
		.xip = MEMC_FLEXSPI_CFG_XIP(DT_DRV_INST(n)),		\
		.ahb_base = (uint8_t *) DT_INST_REG_ADDR_BY_IDX(n, 1),	\
		.ahb_bufferable = DT_INST_PROP(n, ahb_bufferable),	\
		.ahb_cacheable = DT_INST_PROP(n, ahb_cacheable),	\
		.ahb_prefetch = DT_INST_PROP(n, ahb_prefetch),		\
		.ahb_read_addr_opt = DT_INST_PROP(n, ahb_read_addr_opt),\
		.combination_mode = DT_INST_PROP(n, combination_mode),	\
		.sck_differential_clock = DT_INST_PROP(n, sck_differential_clock),	\
		.rx_sample_clock = DT_INST_PROP(n, rx_clock_source),	\
		.buf_cfg = (struct memc_flexspi_buf_cfg *)buf_cfg_##n,	\
		.buf_cfg_cnt = sizeof(buf_cfg_##n) /			\
			sizeof(struct memc_flexspi_buf_cfg),		\
		.pincfg = PINCTRL_DT_INST_DEV_CONFIG_GET(n),		\
		.clock_dev = DEVICE_DT_GET(DT_INST_CLOCKS_CTLR(n)),     \
		.clock_subsys = (clock_control_subsys_t)                \
			DT_INST_CLOCKS_CELL(n, name),                   \
	};								\
									\
	PM_DEVICE_DT_INST_DEFINE(n, memc_flexspi_pm_action);		\
									\
	DEVICE_DT_INST_DEFINE(n,					\
			      memc_flexspi_init,			\
			      PM_DEVICE_DT_INST_GET(n),			\
			      &memc_flexspi_data_##n,			\
			      NULL,					\
			      POST_KERNEL,				\
			      CONFIG_MEMC_INIT_PRIORITY,	\
			      NULL);

DT_INST_FOREACH_STATUS_OKAY(MEMC_FLEXSPI)