linux-nv-oot/drivers/platform/tegra/dce/dce-mailbox.c

// SPDX-License-Identifier: MIT
/*
 * SPDX-FileCopyrightText: Copyright (c) 2019-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */


#include <dce.h>
#include <dce-mailbox.h>
#include <dce-os-utils.h>
#include <interface/dce-interface.h>
#include <interface/dce-boot-cmds.h>


#define CCPLEX_HSP_IE 1U /* TODO : Have an api to read from platform data */
#define DCE_MAILBOX_FULL_INT_SHIFT 8U

/**
 * dce_hsp_get_irq_sources - gets the interrupt sources.
 *
 * @d : Pointer to tegra_dce struct.
 *
 * Return : bitmap for mailbox ids that triggered the irqs.
 */
static u32 dce_hsp_get_irq_sources(struct tegra_dce *d)
{
	return (d->hsp.hsp_ie_read(d, d->hsp_id, CCPLEX_HSP_IE) &
					d->hsp.hsp_ir_read(d, d->hsp_id));
}

/**
 * dce_mailbox_isr - Isr for mailbox irqs.
 *
 * @d : Pointer to tegra_dce struct.
 *
 * Return : Void
 */
void dce_mailbox_isr(struct tegra_dce *d)
{
	u8 i = 0;
	u32 value;
	struct dce_mailbox_interface *d_mb;
	u32 irq_sources = dce_hsp_get_irq_sources(d);

	do {
		d_mb = &d->d_mb[i];
		/**
		 * Get the mailbox on which the interrupt
		 * is received.
		 */
		if (irq_sources & (BIT(d_mb->r_mb)
			<< DCE_MAILBOX_FULL_INT_SHIFT)) {
			/**
			 * Read and store the value.
			 *
			 * TODO : Ignore the full interrupt
			 * bit before storing the result.
			 *
			 */
			value = d->hsp.smb_read(d, d->hsp_id, d_mb->r_mb);
			d->hsp.smb_set(d, 0U, d->hsp_id, d_mb->r_mb);
			dce_mailbox_store_interface_status(d, value, i);
			d_mb->notify(d, d_mb->notify_data);
		}
		i++;
	} while (i < DCE_MAILBOX_MAX_INTERFACES);
}

/**
 * dce_mailbox_store_interface_status - stores the response
 *				received on a mailbox interface.
 * @d : Pointer to tegra_dce struct.
 * @v : Value to be stored.
 * @id : interface id.
 *
 * Return :Void
 */
void dce_mailbox_store_interface_status(struct tegra_dce *d, u32 v, u8 id)
{
	struct dce_mailbox_interface *d_mb = &d->d_mb[id];

	dce_os_mutex_lock(&d_mb->lock);
	d_mb->ack_value = v;
	d_mb->valid = true;
	dce_os_mutex_unlock(&d_mb->lock);
}

/**
 * dce_mailbox_get_interface_status - gets the response
 *					received on mailbox interface.
 * @d : Pointer to tegra_dce struct.
 * @id : Interface id.
 *
 * Return : u32 value
 */
u32 dce_mailbox_get_interface_status(struct tegra_dce *d, u8 id)
{
	struct dce_mailbox_interface *d_mb = &d->d_mb[id];

	if (d_mb->valid)
		return d_mb->ack_value;
	else
		return 0xffffffff;
}

/**
 * dce_mailbox_invalidate_status - renders the response invalid.
 *
 * @d : Pointer to tegra_dce struct.
 * @id : Interface id.
 *
 * Return : void
 */
void dce_mailbox_invalidate_status(struct tegra_dce *d, u8 id)
{
	struct dce_mailbox_interface *d_mb = &d->d_mb[id];

	dce_os_mutex_lock(&d_mb->lock);
	d_mb->valid = false;
	dce_os_mutex_unlock(&d_mb->lock);
}

/**
 * dce_mailbox_write_safe - Checks if it's safe to write to
 *						a mailbox register.
 *
 * @d : Pointer to tegra_dce struct.
 * @id : Mailbox ID
 *
 * Return : true if it's safe
 */
static bool dce_mailbox_write_safe(struct tegra_dce *d, u8 id)
{
	unsigned long val;

	val = d->hsp.smb_read(d, d->hsp_id, id);

	return !(val & BIT(31));
}

/**
 * dce_mailbox_set_full_interrupt - Sets the interrupt tag bit
 *					in the mailbox register
 * @d : Pointer to tegra_dce struct.
 * @id : Mailbox interface id.
 *
 * Return : Void
 */
void dce_mailbox_set_full_interrupt(struct tegra_dce *d, u8 id)
{
	struct dce_mailbox_interface *d_mb;

	d_mb = &d->d_mb[id];

	dce_os_mutex_lock(&d_mb->lock);

	if (!dce_mailbox_write_safe(d, d_mb->s_mb))
		dce_os_info(d, "Intr bit set multiple times for MB : [0x%x] id:[0x%x]",
			 d_mb->s_mb, id);

	d->hsp.smb_set(d, BIT(31), d->hsp_id, d_mb->s_mb);

	dce_os_mutex_unlock(&d_mb->lock);
}

/**
 * dce_handle_mailbox_send_cmd_sync - handler function for
 *				      mailbox_send_cmd_sync
 *
 * @d : Pointer to tegra_dce struct.
 * @cmd : The command to be sent.
 * @interface  : boot or admin interface
 *
 *
 * Return : 0 if successful.
 */
int dce_handle_mailbox_send_cmd_sync(struct tegra_dce *d, u32 cmd, u32 interface)
{
	int ret = 0;
	struct dce_mailbox_interface *d_mb;

	d_mb = &d->d_mb[interface];

	dce_os_mutex_lock(&d_mb->lock);

	if (!dce_mailbox_write_safe(d, d_mb->s_mb)) {
		dce_os_err(d, "Previously sent message isn't synced");
		return -1;
	}

	d->hsp.smb_set(d, cmd | BIT(31), d->hsp_id, d_mb->s_mb);
	d_mb->valid = false;

	dce_os_mutex_unlock(&d_mb->lock);

	ret = d_mb->dce_mailbox_wait(d);

	return ret;
}

/**
 * dce_mailbox_send_cmd_sync - Sends command via mailbox and waits for ack.
 *
 * @d : Pointer to tegra_dce struct.
 * @cmd : The command to be sent.
 * @interface  : boot or admin interface
 *
 * Return : 0 if successful.
 */
int dce_mailbox_send_cmd_sync(struct tegra_dce *d, u32 cmd, u32 interface)
{
	int ret = 0;
	struct dce_mailbox_send_cmd_params params;

	params.cmd = cmd;
	params.interface = interface;

	ret = dce_fsm_post_event(d, EVENT_ID_DCE_BOOT_CMD_MSG_REQUESTED,
				 (void *)&params);
	if (ret) {
		dce_os_err(d, "Unable to send msg ret :%d", ret);
		goto out;
	}

out:
	return ret;
}

/**
 * dce_mailbox_init_interface - Initializes the mailbox interface.
 *
 * @d : Pointer to tegra_dce struct.
 * @id : Mailbox interface id.
 *
 * Return : 0 if successful
 */
int dce_mailbox_init_interface(struct tegra_dce *d, u8 id, u8 s_mb,
		u8 r_mb, int (*dce_mailbox_wait)(struct tegra_dce *),
		void *notify_data, void (*notify)(struct tegra_dce *, void *))
{
	int ret;
	u64 ie_wr_val;
	struct dce_mailbox_interface *d_mb;

	d_mb = &d->d_mb[id];

	ret = dce_os_mutex_init(&d_mb->lock);
	if (ret) {
		dce_os_err(d, "dce lock initialization failed for mailbox");
		goto err_lock_init;
	}

	d_mb->valid = false;

	d->hsp.smb_set_full_ie(d, true, d->hsp_id, r_mb);

	ie_wr_val = BIT(r_mb) << 8U;
	d->hsp.hsp_ie_write(d, ie_wr_val, d->hsp_id, CCPLEX_HSP_IE);

	d_mb->s_mb = s_mb;
	d_mb->r_mb = r_mb;

	d_mb->notify = notify;
	d_mb->notify_data = notify_data;

	d_mb->dce_mailbox_wait
		= dce_mailbox_wait;

	return 0;

err_lock_init:
	return ret;
}

/**
 * dce_mailbox_deinit_interface - Releases the resources
 *					associated with boot interface.
 *
 * @d : Pointer to tegra_dce struct.
 *
 * Return : Void
 */
void dce_mailbox_deinit_interface(struct tegra_dce *d, u8 id)
{
	struct dce_mailbox_interface *d_mb;

	d_mb = &d->d_mb[id];

	dce_os_mutex_destroy(&d_mb->lock);
}