arch/arm/mach-imx/imx8ulp/upower/upower_api.c - filogic/uboot - Gitiles

 // SPDX-License-Identifier: BSD-3-Clause
 /*
  * Copyright 2021 NXP
  */

 #include <linux/types.h>
 #include <string.h>
 #include <asm/arch/imx-regs.h>
 #include <asm/io.h>
 #include "upower_api.h"

 enum upwr_api_state api_state;
 enum soc_domain pwr_domain;
 void *sh_buffer[UPWR_SG_COUNT];
 struct upwr_code_vers fw_rom_version;
 struct upwr_code_vers fw_ram_version;
 u32 fw_launch_option;
 u32 sg_busy;
 struct mu_type *mu;
 upwr_up_max_msg sg_rsp_msg[UPWR_SG_COUNT];
 upwr_callb user_callback[UPWR_SG_COUNT];
 UPWR_RX_CALLB_FUNC_T  sgrp_callback[UPWR_SG_COUNT];
 u32 sg_rsp_siz[UPWR_SG_COUNT];

 #define UPWR_MU_MSG_SIZE            (2)
 #define UPWR_SG_BUSY(sg) (sg_busy & (1 << (sg)))
 #define UPWR_USR_CALLB(sg, cb)		\
 	do {				\
 		user_callback[sg] = cb;	\
 	} while (0)
 #define UPWR_MSG_HDR(hdr, sg, fn)		\
 	(hdr).domain   = (u32)pwr_domain;	\
 	(hdr).srvgrp   = sg;			\
 	(hdr).function = fn

 static u32 upwr_ptr2offset(u64 ptr, enum upwr_sg sg, size_t siz, size_t offset, const void *vptr)
 {
 	if (ptr >= UPWR_DRAM_SHARED_BASE_ADDR &&
 	    ((ptr - UPWR_DRAM_SHARED_BASE_ADDR) < UPWR_DRAM_SHARED_SIZE)) {
 		return (u32)(ptr - UPWR_DRAM_SHARED_BASE_ADDR);
 	}

 	/* pointer is outside the shared memory, copy the struct to buffer */
 	memcpy(offset + (char *)sh_buffer[sg], (void *)vptr, siz);

 	return (u32)((u64)sh_buffer[sg] + offset - UPWR_DRAM_SHARED_BASE_ADDR);
 }

 enum upwr_req_status upwr_req_status(enum upwr_sg sg, u32 *sgfptr, enum upwr_resp *errptr,
 				     int *retptr)
 {
 	enum upwr_req_status status;

 	status = (sg_rsp_msg[sg].hdr.errcode == UPWR_RESP_OK) ? UPWR_REQ_OK : UPWR_REQ_ERR;

 	return status;
 }

 void upwr_copy2tr(struct mu_type *mu, const u32 *msg, u32 size)
 {
 	int i;

 	for (i = size - 1; i > -1; i--)
 		writel(msg[i], &mu->tr[i]);
 }

 int upwr_tx(const u32 *msg, u32 size)
 {
 	if (size > UPWR_MU_MSG_SIZE)
 		return -2;
 	if (!size)
 		return -2;

 	if (readl(&mu->tsr) != UPWR_MU_TSR_EMPTY)
 		return -1;  /* not all TE bits in 1: some data to send still */

 	upwr_copy2tr(mu, msg, size);
 	writel(1 << (size - 1), &mu->tcr);

 	return 0;
 }

 void upwr_srv_req(enum upwr_sg sg, u32 *msg, u32 size)
 {
 	sg_busy |= 1 << sg;

 	upwr_tx(msg, size);
 }

 int upwr_pwm_power_on(const u32 swton[], const u32 memon[], upwr_callb callb)
 {
 	upwr_pwm_pwron_msg txmsg;
 	u64 ptrval; /* needed for X86, ARM64 */
 	size_t stsize = 0;

 	if (api_state != UPWR_API_READY)
 		return -3;
 	if (UPWR_SG_BUSY(UPWR_SG_PWRMGMT))
 		return -1;

 	UPWR_USR_CALLB(UPWR_SG_PWRMGMT, callb);

 	UPWR_MSG_HDR(txmsg.hdr, UPWR_SG_PWRMGMT, UPWR_PWM_PWR_ON);

 	if (!swton)
 		txmsg.ptrs.ptr0 = 0; /* NULL pointer -> 0 offset */
 	else
 		txmsg.ptrs.ptr0 = upwr_ptr2offset(ptrval, UPWR_SG_PWRMGMT,
 						  (stsize = UPWR_PMC_SWT_WORDS * 4), 0, swton);

 	if (!memon)
 		txmsg.ptrs.ptr1 = 0; /* NULL pointer -> 0 offset */
 	else
 		txmsg.ptrs.ptr1 = upwr_ptr2offset(ptrval, UPWR_SG_PWRMGMT, UPWR_PMC_MEM_WORDS * 4,
 						  stsize, memon);

 	upwr_srv_req(UPWR_SG_PWRMGMT, (u32 *)&txmsg, sizeof(txmsg) / 4);

 	return 0;
 }

 enum upwr_req_status upwr_poll_req_status(enum upwr_sg sg, u32 *sgfptr,
 					  enum upwr_resp *errptr, int *retptr,
 					  u32 attempts)
 {
 	u32 i;
 	enum upwr_req_status ret;

 	if (!attempts) {
 		ret = UPWR_REQ_BUSY;
 		while (ret == UPWR_REQ_BUSY)
 			ret = upwr_req_status(sg, sgfptr, errptr, retptr);
 		return ret;
 	}

 	for (i = 0; i < attempts; i++) {
 		ret = upwr_req_status(sg, sgfptr, errptr, retptr);
 		if (ret != UPWR_REQ_BUSY)
 			break;
 	}

 	return ret;
 }

 int upwr_xcp_i2c_access(u16 addr, int8_t data_size, uint8_t subaddr_size, u32 subaddr,
 			u32 wdata, const upwr_callb callb)
 {
 	u64 ptrval = (u64)sh_buffer[UPWR_SG_EXCEPT];
 	struct upwr_i2c_access *i2c_acc_ptr = (struct upwr_i2c_access *)ptrval;
 	struct upwr_pointer_msg txmsg;

 	if (api_state != UPWR_API_READY)
 		return -3;
 	if (UPWR_SG_BUSY(UPWR_SG_EXCEPT))
 		return -1;

 	UPWR_USR_CALLB(UPWR_SG_EXCEPT, callb);

 	UPWR_MSG_HDR(txmsg.hdr, UPWR_SG_EXCEPT, UPWR_XCP_I2C);

 	i2c_acc_ptr->addr = addr;
 	i2c_acc_ptr->subaddr = subaddr;
 	i2c_acc_ptr->subaddr_size = subaddr_size;
 	i2c_acc_ptr->data = wdata;
 	i2c_acc_ptr->data_size = data_size;

 	txmsg.ptr = upwr_ptr2offset(ptrval,
 				    UPWR_SG_EXCEPT,
 				    (size_t)sizeof(struct upwr_i2c_access),
 				    0,
 				    i2c_acc_ptr);

 	upwr_srv_req(UPWR_SG_EXCEPT, (u32 *)&txmsg, sizeof(txmsg) / 4);

 	return 0;
 }

 int upwr_xcp_set_ddr_retention(enum soc_domain domain, u32 enable, const upwr_callb callb)
 {
 	union upwr_down_1w_msg txmsg;

 	if (api_state != UPWR_API_READY)
 		return -3;
 	if (UPWR_SG_BUSY(UPWR_SG_EXCEPT))
 		return -1;

 	UPWR_USR_CALLB(UPWR_SG_EXCEPT, callb);

 	UPWR_MSG_HDR(txmsg.hdr, UPWR_SG_EXCEPT, UPWR_XCP_SET_DDR_RETN);
 	txmsg.hdr.domain = (u32)domain;
 	txmsg.hdr.arg    = (u32)enable;

 	upwr_srv_req(UPWR_SG_EXCEPT, (u32 *)&txmsg, sizeof(txmsg) / 4);

 	return 0;
 }

 int upwr_rx(u32 *msg, u32 *size)
 {
 	u32 len = readl(&mu->rsr);

 	len = (len == 0x0) ? 0 :
 	      (len == 0x1) ? 1 :
 	      #if UPWR_MU_MSG_SIZE > 1
 	      (len == 0x3) ? 2 :
 	      #if UPWR_MU_MSG_SIZE > 2
 	      (len == 0x7) ? 3 :
 	      #if UPWR_MU_MSG_SIZE > 3
 	      (len == 0xF) ? 4 :
 	      #endif
 	      #endif
 	      #endif
 	      0xFFFFFFFF; /* something wrong */

 	if (len == 0xFFFFFFFF)
 		return -3;

 	*size = len;
 	if (!len)
 		return -1;

 	/* copy the received message to the rx queue, so the interrupts are cleared; */
 	for (u32 i = 0; i < len; i++)
 		msg[i] = readl(&mu->rr[i]);

 	return 0;
 }

 void msg_copy(u32 *dest, u32 *src, u32 size)
 {
 	*dest = *src;
 	if (size > 1)
 		*(dest + 1) = *(src + 1);
 }

 void upwr_mu_int_callback(void)
 {
 	enum upwr_sg sg;	/* service group number */
 	UPWR_RX_CALLB_FUNC_T sg_callb; /* service group callback */
 	struct upwr_up_2w_msg rxmsg;
 	u32 size;	/* in words */

 	if (upwr_rx((u32 *)&rxmsg, &size) < 0) {
 		UPWR_API_ASSERT(0);
 		return;
 	}

 	sg = (enum upwr_sg)rxmsg.hdr.srvgrp;

 	/* copy msg to the service group buffer */
 	msg_copy((u32 *)&sg_rsp_msg[sg], (u32 *)&rxmsg, size);
 	sg_rsp_siz[sg] = size;
 	sg_busy &= ~(1 << sg);

 	sg_callb = sgrp_callback[sg];
 	if (!sg_callb) {
 		upwr_callb user_callb = user_callback[sg];

 		/* no service group callback; call the user callback if any */
 		if (!user_callb)
 			goto done; /* no user callback */

 		/* make the user callback */
 		user_callb(sg, rxmsg.hdr.function, (enum upwr_resp)rxmsg.hdr.errcode,
 			   (int)(size == 2) ? rxmsg.word2 : rxmsg.hdr.ret);
 		goto done;
 	}

 	/* finally make the group callback */
 	sg_callb();
 	/* don't uninstall the group callback, it's permanent */
 done:
 	if (rxmsg.hdr.errcode == UPWR_RESP_SHUTDOWN) /* shutdown error: */
 		api_state = UPWR_API_INITLZED;
 }

 void upwr_txrx_isr(void)
 {
 	if (readl(&mu->rsr))
 		upwr_mu_int_callback();
 }

 void upwr_start_callb(void)
 {
 	switch (api_state) {
 	case UPWR_API_START_WAIT:
 	{
 		upwr_rdy_callb start_callb = (upwr_rdy_callb)user_callback[UPWR_SG_EXCEPT];

 		union upwr_ready_msg *msg = (union upwr_ready_msg *)&sg_rsp_msg[UPWR_SG_EXCEPT];

 		/* message sanity check */
 		UPWR_API_ASSERT(msg->hdr.srvgrp   == UPWR_SG_EXCEPT);
 		UPWR_API_ASSERT(msg->hdr.function == UPWR_XCP_START);
 		UPWR_API_ASSERT(msg->hdr.errcode  == UPWR_RESP_OK);

 		fw_ram_version.soc_id = fw_rom_version.soc_id;
 		fw_ram_version.vmajor = msg->args.vmajor;
 		fw_ram_version.vminor = msg->args.vminor;
 		fw_ram_version.vfixes = msg->args.vfixes;

 		/*
 		 * vmajor == vminor == vfixes == 0 indicates start error
 		 * in this case, go back to the INITLZED state
 		 */

 		if (fw_ram_version.vmajor || fw_ram_version.vminor || fw_ram_version.vfixes) {
 			api_state = UPWR_API_READY;

 			/* initialization is over: uninstall the callbacks just in case */
 			UPWR_USR_CALLB(UPWR_SG_EXCEPT, NULL);
 			sgrp_callback[UPWR_SG_EXCEPT] = NULL;

 			if (!fw_launch_option) {
 				/* launched ROM firmware: RAM fw versions must be all 0s */
 				fw_ram_version.vmajor =
 				fw_ram_version.vminor =
 				fw_ram_version.vfixes = 0;
 			}
 		} else {
 			api_state = UPWR_API_INITLZED;
 		}

 		start_callb(msg->args.vmajor, msg->args.vminor, msg->args.vfixes);
 	}
 	break;

 	default:
 		UPWR_API_ASSERT(0);
 		break;
 	}
 }

 int upwr_init(enum soc_domain domain, struct mu_type *muptr)
 {
 	u32 dom_buffer_base = ((UPWR_API_BUFFER_ENDPLUS + UPWR_API_BUFFER_BASE) / 2);
 	union upwr_init_msg *msg = (union upwr_init_msg *)&sg_rsp_msg[UPWR_SG_EXCEPT];
 	enum upwr_sg sg; /* service group number */
 	u32 size; /* in words */
 	int j;

 	mu = muptr;
 	writel(0, &mu->tcr);
 	writel(0, &mu->rcr);

 	api_state = UPWR_API_INIT_WAIT;
 	pwr_domain = domain;
 	sg_busy = 0;

 	/* initialize the versions, in case they are polled */
 	fw_rom_version.soc_id =
 	fw_rom_version.vmajor =
 	fw_rom_version.vminor =
 	fw_rom_version.vfixes = 0;

 	fw_ram_version.soc_id =
 	fw_ram_version.vmajor =
 	fw_ram_version.vminor =
 	fw_ram_version.vfixes = 0;

 	sh_buffer[UPWR_SG_EXCEPT] = (void *)(ulong)dom_buffer_base;
 	sh_buffer[UPWR_SG_PWRMGMT] = (void *)(ulong)(dom_buffer_base +
 						     sizeof(union upwr_xcp_union));
 	sh_buffer[UPWR_SG_DELAYM] = NULL;
 	sh_buffer[UPWR_SG_VOLTM] = NULL;
 	sh_buffer[UPWR_SG_CURRM] = NULL;
 	sh_buffer[UPWR_SG_TEMPM] = NULL;
 	sh_buffer[UPWR_SG_DIAG] = NULL;
 	/* (no buffers service groups other than xcp and pwm for now) */

 	for (j = 0; j < UPWR_SG_COUNT; j++) {
 		user_callback[j] = NULL;
 		/* service group Exception gets the initialization callbacks */
 		sgrp_callback[j] = (j == UPWR_SG_EXCEPT) ? upwr_start_callb : NULL;

 		/* response messages with an initial consistent content */
 		sg_rsp_msg[j].hdr.errcode = UPWR_RESP_SHUTDOWN;
 	}

 	if (readl(&mu->fsr) & BIT(0)) {
 		/* send a ping message down to get the ROM version back */
 		upwr_xcp_ping_msg ping_msg;

 		ping_msg.hdr.domain = pwr_domain;
 		ping_msg.hdr.srvgrp = UPWR_SG_EXCEPT;
 		ping_msg.hdr.function = UPWR_XCP_PING;

 		if (readl(&mu->rsr) & BIT(0)) /* first clean any Rx message left over */
 			upwr_rx((u32 *)msg, &size);

 		while (readl(&mu->tsr) != UPWR_MU_TSR_EMPTY)
 			;

 		/*
 		 * now send the ping message;
 		 * do not use upwr_tx, which needs API initilized;
 		 * just write to the MU TR register(s)
 		 */
 		setbits_le32(&mu->fcr, BIT(0)); /* flag urgency status */
 		upwr_copy2tr(mu, (u32 *)&ping_msg, sizeof(ping_msg) / 4);
 	}

 	do {
 		/* poll for the MU Rx status: wait for an init message, either
 		 * 1st sent from uPower after reset or as a response to a ping
 		 */
 		while (!readl(&mu->rsr) & BIT(0))
 			;

 		clrbits_le32(&mu->fcr, BIT(0));

 		if (upwr_rx((u32 *)msg, &size) < 0)
 			return -4;

 		if (size != (sizeof(union upwr_init_msg) / 4)) {
 			if (readl(&mu->fsr) & BIT(0))
 				continue; /* discard left over msg */
 			else
 				return -4;
 		}

 		sg = (enum upwr_sg)msg->hdr.srvgrp;
 		if (sg != UPWR_SG_EXCEPT) {
 			if (readl(&mu->fsr) & BIT(0))
 				continue;
 			else
 				return -4;
 		}

 		if ((enum upwr_xcp_f)msg->hdr.function   != UPWR_XCP_INIT) {
 			if (readl(&mu->fsr) & BIT(0))
 				continue;
 			else
 				return -4;
 		}

 		break;
 	} while (true);

 	fw_rom_version.soc_id = msg->args.soc;
 	fw_rom_version.vmajor = msg->args.vmajor;
 	fw_rom_version.vminor = msg->args.vminor;
 	fw_rom_version.vfixes = msg->args.vfixes;

 	api_state = UPWR_API_INITLZED;

 	return 0;
 } /* upwr_init */

 int upwr_start(u32 launchopt, const upwr_rdy_callb rdycallb)
 {
 	upwr_start_msg txmsg;

 	if (api_state != UPWR_API_INITLZED)
 		return -3;

 	UPWR_USR_CALLB(UPWR_SG_EXCEPT, (upwr_callb)rdycallb);

 	UPWR_MSG_HDR(txmsg.hdr, UPWR_SG_EXCEPT, UPWR_XCP_START);

 	txmsg.hdr.arg = launchopt;
 	fw_launch_option = launchopt;

 	if (upwr_tx((u32 *)&txmsg, sizeof(txmsg) / 4) < 0) {
 		/* catastrophic error, but is it possible to happen? */
 		UPWR_API_ASSERT(0);
 		return -1;
 	}

 	api_state = UPWR_API_START_WAIT;

 	return 0;
 }

 u32 upwr_rom_version(u32 *vmajor, u32 *vminor, u32 *vfixes)
 {
 	u32 soc;

 	soc = fw_rom_version.soc_id;
 	*vmajor = fw_rom_version.vmajor;
 	*vminor = fw_rom_version.vminor;
 	*vfixes = fw_rom_version.vfixes;

 	return soc;
 }
	// SPDX-License-Identifier: BSD-3-Clause
	/*
	* Copyright 2021 NXP
	*/

	#include <linux/types.h>
	#include <string.h>
	#include <asm/arch/imx-regs.h>
	#include <asm/io.h>
	#include "upower_api.h"

	enum upwr_api_state api_state;
	enum soc_domain pwr_domain;
	void *sh_buffer[UPWR_SG_COUNT];
	struct upwr_code_vers fw_rom_version;
	struct upwr_code_vers fw_ram_version;
	u32 fw_launch_option;
	u32 sg_busy;
	struct mu_type *mu;
	upwr_up_max_msg sg_rsp_msg[UPWR_SG_COUNT];
	upwr_callb user_callback[UPWR_SG_COUNT];
	UPWR_RX_CALLB_FUNC_T sgrp_callback[UPWR_SG_COUNT];
	u32 sg_rsp_siz[UPWR_SG_COUNT];

	#define UPWR_MU_MSG_SIZE (2)
	#define UPWR_SG_BUSY(sg) (sg_busy & (1 << (sg)))
	#define UPWR_USR_CALLB(sg, cb) \
	do { \
	user_callback[sg] = cb; \
	} while (0)
	#define UPWR_MSG_HDR(hdr, sg, fn) \
	(hdr).domain = (u32)pwr_domain; \
	(hdr).srvgrp = sg; \
	(hdr).function = fn

	static u32 upwr_ptr2offset(u64 ptr, enum upwr_sg sg, size_t siz, size_t offset, const void *vptr)
	{
	if (ptr >= UPWR_DRAM_SHARED_BASE_ADDR &&
	((ptr - UPWR_DRAM_SHARED_BASE_ADDR) < UPWR_DRAM_SHARED_SIZE)) {
	return (u32)(ptr - UPWR_DRAM_SHARED_BASE_ADDR);
	}

	/* pointer is outside the shared memory, copy the struct to buffer */
	memcpy(offset + (char )sh_buffer[sg], (void )vptr, siz);

	return (u32)((u64)sh_buffer[sg] + offset - UPWR_DRAM_SHARED_BASE_ADDR);
	}

	enum upwr_req_status upwr_req_status(enum upwr_sg sg, u32 sgfptr, enum upwr_resp errptr,
	int *retptr)
	{
	enum upwr_req_status status;

	status = (sg_rsp_msg[sg].hdr.errcode == UPWR_RESP_OK) ? UPWR_REQ_OK : UPWR_REQ_ERR;

	return status;
	}

	void upwr_copy2tr(struct mu_type mu, const u32 msg, u32 size)
	{
	int i;

	for (i = size - 1; i > -1; i--)
	writel(msg[i], &mu->tr[i]);
	}

	int upwr_tx(const u32 *msg, u32 size)
	{
	if (size > UPWR_MU_MSG_SIZE)
	return -2;
	if (!size)
	return -2;

	if (readl(&mu->tsr) != UPWR_MU_TSR_EMPTY)
	return -1; /* not all TE bits in 1: some data to send still */

	upwr_copy2tr(mu, msg, size);
	writel(1 << (size - 1), &mu->tcr);

	return 0;
	}

	void upwr_srv_req(enum upwr_sg sg, u32 *msg, u32 size)
	{
	sg_busy \|= 1 << sg;

	upwr_tx(msg, size);
	}

	int upwr_pwm_power_on(const u32 swton[], const u32 memon[], upwr_callb callb)
	{
	upwr_pwm_pwron_msg txmsg;
	u64 ptrval; /* needed for X86, ARM64 */
	size_t stsize = 0;

	if (api_state != UPWR_API_READY)
	return -3;
	if (UPWR_SG_BUSY(UPWR_SG_PWRMGMT))
	return -1;

	UPWR_USR_CALLB(UPWR_SG_PWRMGMT, callb);

	UPWR_MSG_HDR(txmsg.hdr, UPWR_SG_PWRMGMT, UPWR_PWM_PWR_ON);

	if (!swton)
	txmsg.ptrs.ptr0 = 0; /* NULL pointer -> 0 offset */
	else
	txmsg.ptrs.ptr0 = upwr_ptr2offset(ptrval, UPWR_SG_PWRMGMT,
	(stsize = UPWR_PMC_SWT_WORDS * 4), 0, swton);

	if (!memon)
	txmsg.ptrs.ptr1 = 0; /* NULL pointer -> 0 offset */
	else
	txmsg.ptrs.ptr1 = upwr_ptr2offset(ptrval, UPWR_SG_PWRMGMT, UPWR_PMC_MEM_WORDS * 4,
	stsize, memon);

	upwr_srv_req(UPWR_SG_PWRMGMT, (u32 *)&txmsg, sizeof(txmsg) / 4);

	return 0;
	}

	enum upwr_req_status upwr_poll_req_status(enum upwr_sg sg, u32 *sgfptr,
	enum upwr_resp errptr, int retptr,
	u32 attempts)
	{
	u32 i;
	enum upwr_req_status ret;

	if (!attempts) {
	ret = UPWR_REQ_BUSY;
	while (ret == UPWR_REQ_BUSY)
	ret = upwr_req_status(sg, sgfptr, errptr, retptr);
	return ret;
	}

	for (i = 0; i < attempts; i++) {
	ret = upwr_req_status(sg, sgfptr, errptr, retptr);
	if (ret != UPWR_REQ_BUSY)
	break;
	}

	return ret;
	}

	int upwr_xcp_i2c_access(u16 addr, int8_t data_size, uint8_t subaddr_size, u32 subaddr,
	u32 wdata, const upwr_callb callb)
	{
	u64 ptrval = (u64)sh_buffer[UPWR_SG_EXCEPT];
	struct upwr_i2c_access i2c_acc_ptr = (struct upwr_i2c_access )ptrval;
	struct upwr_pointer_msg txmsg;

	if (api_state != UPWR_API_READY)
	return -3;
	if (UPWR_SG_BUSY(UPWR_SG_EXCEPT))
	return -1;

	UPWR_USR_CALLB(UPWR_SG_EXCEPT, callb);

	UPWR_MSG_HDR(txmsg.hdr, UPWR_SG_EXCEPT, UPWR_XCP_I2C);

	i2c_acc_ptr->addr = addr;
	i2c_acc_ptr->subaddr = subaddr;
	i2c_acc_ptr->subaddr_size = subaddr_size;
	i2c_acc_ptr->data = wdata;
	i2c_acc_ptr->data_size = data_size;

	txmsg.ptr = upwr_ptr2offset(ptrval,
	UPWR_SG_EXCEPT,
	(size_t)sizeof(struct upwr_i2c_access),
	0,
	i2c_acc_ptr);

	upwr_srv_req(UPWR_SG_EXCEPT, (u32 *)&txmsg, sizeof(txmsg) / 4);

	return 0;
	}

	int upwr_xcp_set_ddr_retention(enum soc_domain domain, u32 enable, const upwr_callb callb)
	{
	union upwr_down_1w_msg txmsg;

	if (api_state != UPWR_API_READY)
	return -3;
	if (UPWR_SG_BUSY(UPWR_SG_EXCEPT))
	return -1;

	UPWR_USR_CALLB(UPWR_SG_EXCEPT, callb);

	UPWR_MSG_HDR(txmsg.hdr, UPWR_SG_EXCEPT, UPWR_XCP_SET_DDR_RETN);
	txmsg.hdr.domain = (u32)domain;
	txmsg.hdr.arg = (u32)enable;

	upwr_srv_req(UPWR_SG_EXCEPT, (u32 *)&txmsg, sizeof(txmsg) / 4);

	return 0;
	}

	int upwr_rx(u32 msg, u32 size)
	{
	u32 len = readl(&mu->rsr);

	len = (len == 0x0) ? 0 :
	(len == 0x1) ? 1 :
	#if UPWR_MU_MSG_SIZE > 1
	(len == 0x3) ? 2 :
	#if UPWR_MU_MSG_SIZE > 2
	(len == 0x7) ? 3 :
	#if UPWR_MU_MSG_SIZE > 3
	(len == 0xF) ? 4 :
	#endif
	#endif
	#endif
	0xFFFFFFFF; /* something wrong */

	if (len == 0xFFFFFFFF)
	return -3;

	*size = len;
	if (!len)
	return -1;

	/* copy the received message to the rx queue, so the interrupts are cleared; */
	for (u32 i = 0; i < len; i++)
	msg[i] = readl(&mu->rr[i]);

	return 0;
	}

	void msg_copy(u32 dest, u32 src, u32 size)
	{
	dest = src;
	if (size > 1)
	(dest + 1) = (src + 1);
	}

	void upwr_mu_int_callback(void)
	{
	enum upwr_sg sg; /* service group number */
	UPWR_RX_CALLB_FUNC_T sg_callb; /* service group callback */
	struct upwr_up_2w_msg rxmsg;
	u32 size; /* in words */

	if (upwr_rx((u32 *)&rxmsg, &size) < 0) {
	UPWR_API_ASSERT(0);
	return;
	}

	sg = (enum upwr_sg)rxmsg.hdr.srvgrp;

	/* copy msg to the service group buffer */
	msg_copy((u32 )&sg_rsp_msg[sg], (u32 )&rxmsg, size);
	sg_rsp_siz[sg] = size;
	sg_busy &= ~(1 << sg);

	sg_callb = sgrp_callback[sg];
	if (!sg_callb) {
	upwr_callb user_callb = user_callback[sg];

	/* no service group callback; call the user callback if any */
	if (!user_callb)
	goto done; /* no user callback */

	/* make the user callback */
	user_callb(sg, rxmsg.hdr.function, (enum upwr_resp)rxmsg.hdr.errcode,
	(int)(size == 2) ? rxmsg.word2 : rxmsg.hdr.ret);
	goto done;
	}

	/* finally make the group callback */
	sg_callb();
	/* don't uninstall the group callback, it's permanent */
	done:
	if (rxmsg.hdr.errcode == UPWR_RESP_SHUTDOWN) /* shutdown error: */
	api_state = UPWR_API_INITLZED;
	}

	void upwr_txrx_isr(void)
	{
	if (readl(&mu->rsr))
	upwr_mu_int_callback();
	}

	void upwr_start_callb(void)
	{
	switch (api_state) {
	case UPWR_API_START_WAIT:
	{
	upwr_rdy_callb start_callb = (upwr_rdy_callb)user_callback[UPWR_SG_EXCEPT];

	union upwr_ready_msg msg = (union upwr_ready_msg )&sg_rsp_msg[UPWR_SG_EXCEPT];

	/* message sanity check */
	UPWR_API_ASSERT(msg->hdr.srvgrp == UPWR_SG_EXCEPT);
	UPWR_API_ASSERT(msg->hdr.function == UPWR_XCP_START);
	UPWR_API_ASSERT(msg->hdr.errcode == UPWR_RESP_OK);

	fw_ram_version.soc_id = fw_rom_version.soc_id;
	fw_ram_version.vmajor = msg->args.vmajor;
	fw_ram_version.vminor = msg->args.vminor;
	fw_ram_version.vfixes = msg->args.vfixes;

	/*
	* vmajor == vminor == vfixes == 0 indicates start error
	* in this case, go back to the INITLZED state
	*/

	if (fw_ram_version.vmajor \|\| fw_ram_version.vminor \|\| fw_ram_version.vfixes) {
	api_state = UPWR_API_READY;

	/* initialization is over: uninstall the callbacks just in case */
	UPWR_USR_CALLB(UPWR_SG_EXCEPT, NULL);
	sgrp_callback[UPWR_SG_EXCEPT] = NULL;

	if (!fw_launch_option) {
	/* launched ROM firmware: RAM fw versions must be all 0s */
	fw_ram_version.vmajor =
	fw_ram_version.vminor =
	fw_ram_version.vfixes = 0;
	}
	} else {
	api_state = UPWR_API_INITLZED;
	}

	start_callb(msg->args.vmajor, msg->args.vminor, msg->args.vfixes);
	}
	break;

	default:
	UPWR_API_ASSERT(0);
	break;
	}
	}

	int upwr_init(enum soc_domain domain, struct mu_type *muptr)
	{
	u32 dom_buffer_base = ((UPWR_API_BUFFER_ENDPLUS + UPWR_API_BUFFER_BASE) / 2);
	union upwr_init_msg msg = (union upwr_init_msg )&sg_rsp_msg[UPWR_SG_EXCEPT];
	enum upwr_sg sg; /* service group number */
	u32 size; /* in words */
	int j;

	mu = muptr;
	writel(0, &mu->tcr);
	writel(0, &mu->rcr);

	api_state = UPWR_API_INIT_WAIT;
	pwr_domain = domain;
	sg_busy = 0;

	/* initialize the versions, in case they are polled */
	fw_rom_version.soc_id =
	fw_rom_version.vmajor =
	fw_rom_version.vminor =
	fw_rom_version.vfixes = 0;

	fw_ram_version.soc_id =
	fw_ram_version.vmajor =
	fw_ram_version.vminor =
	fw_ram_version.vfixes = 0;

	sh_buffer[UPWR_SG_EXCEPT] = (void *)(ulong)dom_buffer_base;
	sh_buffer[UPWR_SG_PWRMGMT] = (void *)(ulong)(dom_buffer_base +
	sizeof(union upwr_xcp_union));
	sh_buffer[UPWR_SG_DELAYM] = NULL;
	sh_buffer[UPWR_SG_VOLTM] = NULL;
	sh_buffer[UPWR_SG_CURRM] = NULL;
	sh_buffer[UPWR_SG_TEMPM] = NULL;
	sh_buffer[UPWR_SG_DIAG] = NULL;
	/* (no buffers service groups other than xcp and pwm for now) */

	for (j = 0; j < UPWR_SG_COUNT; j++) {
	user_callback[j] = NULL;
	/* service group Exception gets the initialization callbacks */
	sgrp_callback[j] = (j == UPWR_SG_EXCEPT) ? upwr_start_callb : NULL;

	/* response messages with an initial consistent content */
	sg_rsp_msg[j].hdr.errcode = UPWR_RESP_SHUTDOWN;
	}

	if (readl(&mu->fsr) & BIT(0)) {
	/* send a ping message down to get the ROM version back */
	upwr_xcp_ping_msg ping_msg;

	ping_msg.hdr.domain = pwr_domain;
	ping_msg.hdr.srvgrp = UPWR_SG_EXCEPT;
	ping_msg.hdr.function = UPWR_XCP_PING;

	if (readl(&mu->rsr) & BIT(0)) /* first clean any Rx message left over */
	upwr_rx((u32 *)msg, &size);

	while (readl(&mu->tsr) != UPWR_MU_TSR_EMPTY)
	;

	/*
	* now send the ping message;
	* do not use upwr_tx, which needs API initilized;
	* just write to the MU TR register(s)
	*/
	setbits_le32(&mu->fcr, BIT(0)); /* flag urgency status */
	upwr_copy2tr(mu, (u32 *)&ping_msg, sizeof(ping_msg) / 4);
	}

	do {
	/* poll for the MU Rx status: wait for an init message, either
	* 1st sent from uPower after reset or as a response to a ping
	*/
	while (!readl(&mu->rsr) & BIT(0))
	;

	clrbits_le32(&mu->fcr, BIT(0));

	if (upwr_rx((u32 *)msg, &size) < 0)
	return -4;

	if (size != (sizeof(union upwr_init_msg) / 4)) {
	if (readl(&mu->fsr) & BIT(0))
	continue; /* discard left over msg */
	else
	return -4;
	}

	sg = (enum upwr_sg)msg->hdr.srvgrp;
	if (sg != UPWR_SG_EXCEPT) {
	if (readl(&mu->fsr) & BIT(0))
	continue;
	else
	return -4;
	}

	if ((enum upwr_xcp_f)msg->hdr.function != UPWR_XCP_INIT) {
	if (readl(&mu->fsr) & BIT(0))
	continue;
	else
	return -4;
	}

	break;
	} while (true);

	fw_rom_version.soc_id = msg->args.soc;
	fw_rom_version.vmajor = msg->args.vmajor;
	fw_rom_version.vminor = msg->args.vminor;
	fw_rom_version.vfixes = msg->args.vfixes;

	api_state = UPWR_API_INITLZED;

	return 0;
	} /* upwr_init */

	int upwr_start(u32 launchopt, const upwr_rdy_callb rdycallb)
	{
	upwr_start_msg txmsg;

	if (api_state != UPWR_API_INITLZED)
	return -3;

	UPWR_USR_CALLB(UPWR_SG_EXCEPT, (upwr_callb)rdycallb);

	UPWR_MSG_HDR(txmsg.hdr, UPWR_SG_EXCEPT, UPWR_XCP_START);

	txmsg.hdr.arg = launchopt;
	fw_launch_option = launchopt;

	if (upwr_tx((u32 *)&txmsg, sizeof(txmsg) / 4) < 0) {
	/* catastrophic error, but is it possible to happen? */
	UPWR_API_ASSERT(0);
	return -1;
	}

	api_state = UPWR_API_START_WAIT;

	return 0;
	}

	u32 upwr_rom_version(u32 vmajor, u32 vminor, u32 *vfixes)
	{
	u32 soc;

	soc = fw_rom_version.soc_id;
	*vmajor = fw_rom_version.vmajor;
	*vminor = fw_rom_version.vminor;
	*vfixes = fw_rom_version.vfixes;

	return soc;
	}