139 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			139 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
| // SPDX-License-Identifier: GPL-2.0+
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| /*
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|  * Copyright (C) 2020 Linaro Limited.
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|  */
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| 
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| #define LOG_CATEGORY UCLASS_SCMI_AGENT
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| 
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| #include <common.h>
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| #include <dm.h>
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| #include <errno.h>
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| #include <scmi_agent.h>
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| #include <scmi_agent-uclass.h>
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| #include <dm/devres.h>
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| #include <dm/device_compat.h>
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| #include <dm/device-internal.h>
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| #include <linux/arm-smccc.h>
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| #include <linux/compat.h>
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| 
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| #include "smt.h"
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| 
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| #define SMCCC_RET_NOT_SUPPORTED         ((unsigned long)-1)
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| 
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| /**
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|  * struct scmi_smccc_channel - Description of an SCMI SMCCC transport
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|  * @func_id:	SMCCC function ID used by the SCMI transport
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|  * @smt:	Shared memory buffer
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|  */
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| struct scmi_smccc_channel {
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| 	ulong func_id;
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| 	struct scmi_smt smt;
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| };
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| 
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| /**
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|  * struct scmi_channel - Channel instance referenced in SCMI drivers
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|  * @ref: Reference to local channel instance
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|  **/
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| struct scmi_channel {
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| 	struct scmi_smccc_channel ref;
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| };
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| 
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| static int scmi_smccc_process_msg(struct udevice *dev,
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| 				  struct scmi_channel *channel,
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| 				  struct scmi_msg *msg)
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| {
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| 	struct scmi_smccc_channel *chan = &channel->ref;
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| 	struct arm_smccc_res res;
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| 	int ret;
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| 
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| 	ret = scmi_write_msg_to_smt(dev, &chan->smt, msg);
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| 	if (ret)
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| 		return ret;
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| 
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| 	arm_smccc_smc(chan->func_id, 0, 0, 0, 0, 0, 0, 0, &res);
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| 	if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
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| 		ret = -ENXIO;
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| 	else
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| 		ret = scmi_read_resp_from_smt(dev, &chan->smt, msg);
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| 
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| 	scmi_clear_smt_channel(&chan->smt);
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| 
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| 	return ret;
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| }
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| 
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| static int setup_channel(struct udevice *dev, struct scmi_smccc_channel *chan)
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| {
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| 	u32 func_id;
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| 	int ret;
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| 
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| 	if (dev_read_u32(dev, "arm,smc-id", &func_id)) {
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| 		dev_err(dev, "Missing property func-id\n");
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| 		return -EINVAL;
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| 	}
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| 
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| 	chan->func_id = func_id;
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| 
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| 	ret = scmi_dt_get_smt_buffer(dev, &chan->smt);
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| 	if (ret)
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| 		dev_err(dev, "Failed to get smt resources: %d\n", ret);
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| 
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| 	return ret;
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| }
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| 
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| static int scmi_smccc_get_channel(struct udevice *dev,
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| 				  struct scmi_channel **channel)
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| {
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| 	struct scmi_smccc_channel *base_chan = dev_get_plat(dev);
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| 	struct scmi_smccc_channel *chan;
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| 	u32 func_id;
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| 	int ret;
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| 
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| 	if (dev_read_u32(dev, "arm,smc-id", &func_id)) {
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| 		/* Uses agent base channel */
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| 		*channel = container_of(base_chan, struct scmi_channel, ref);
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| 
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| 		return 0;
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| 	}
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| 
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| 	/* Setup a dedicated channel */
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| 	chan = calloc(1, sizeof(*chan));
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| 	if (!chan)
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| 		return -ENOMEM;
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| 
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| 	ret = setup_channel(dev, chan);
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| 	if (ret) {
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| 		free(chan);
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| 		return ret;
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| 	}
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| 
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| 	*channel = container_of(chan, struct scmi_channel, ref);
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| 
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| 	return 0;
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| }
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| 
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| static int scmi_smccc_of_to_plat(struct udevice *dev)
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| {
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| 	struct scmi_smccc_channel *chan = dev_get_plat(dev);
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| 
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| 	return setup_channel(dev, chan);
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| }
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| 
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| static const struct udevice_id scmi_smccc_ids[] = {
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| 	{ .compatible = "arm,scmi-smc" },
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| 	{ }
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| };
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| 
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| static const struct scmi_agent_ops scmi_smccc_ops = {
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| 	.of_get_channel = scmi_smccc_get_channel,
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| 	.process_msg = scmi_smccc_process_msg,
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| };
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| 
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| U_BOOT_DRIVER(scmi_smccc) = {
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| 	.name		= "scmi-over-smccc",
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| 	.id		= UCLASS_SCMI_AGENT,
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| 	.of_match	= scmi_smccc_ids,
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| 	.plat_auto	= sizeof(struct scmi_smccc_channel),
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| 	.of_to_plat	= scmi_smccc_of_to_plat,
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| 	.ops		= &scmi_smccc_ops,
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| };
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