drivers/mailbox/pcc.c

6  *  PCC (Platform Communication Channel) is defined in the ACPI 5.0+
11  *  shared memory regions as defined in the PCC table entries. The PCC
12  *  specification supports a Doorbell mechanism for the PCC clients
14  *  is also specified in each PCC table entry.
18  *  PCC Reads:
22  *  * Client issues mbox_send_message() which rings the PCC doorbell
23  *		for its PCC channel.
28  *  PCC Writes:
33  *  * Client issues mbox_send_message() which rings the PCC doorbell
34  *		for its PCC channel.
42  *	For more details about PCC, please see the ACPI specification from
45  *  This file implements PCC as a Mailbox controller and allows for PCC
60 #include <acpi/pcc.h>
64 #define MBOX_IRQ_NAME		"pcc-mbox"
67  * struct pcc_chan_reg - PCC register bundle
84  * struct pcc_chan_info - PCC channel specific information
86  * @chan: PCC channel information with Shared Memory Region info
87  * @db: PCC register bundle for the doorbell register
88  * @plat_irq_ack: PCC register bundle for the platform interrupt acknowledge
90  * @cmd_complete: PCC register bundle for the command complete check register
91  * @cmd_update: PCC register bundle for the command complete update register
92  * @error: PCC register bundle for the error status register
94  * @type: PCC subspace type
123  * PCC can be used with perf critical drivers such as CPPC
125  * use it to read/write to PCC registers such as doorbell register
128  * write from perf critical registers such as PCC doorbell register
214  * pcc_map_interrupt - Map a PCC subspace GSI to a linux IRQ number
262 	 * If this is PCC slave subspace channel, and the command complete  in pcc_mbox_cmd_complete_check()
273  * pcc_mbox_irq - PCC mailbox interrupt handler
310 	 * The PCC slave subspace channel needs to set the command complete bit  in pcc_mbox_irq()
313 	 * The PCC master subspace channel clears chan_in_use to free channel.  in pcc_mbox_irq()
323  * pcc_mbox_request_channel - PCC clients call this function to
324  *		request a pointer to their PCC subspace, from which they
328  * @subspace_id: The PCC Subspace index as parsed in the PCC client
329  *		ACPI package. This is used to lookup the array of PCC
330  *		subspaces as parsed by the PCC Mailbox controller.
332  * Return: Pointer to the PCC Mailbox Channel if successful or ERR_PTR.
362  * @pchan: Pointer to the PCC mailbox channel as returned by
378  *		here only to ring the channel doorbell. The PCC client
380  *		order to maintain atomicity over PCC channel once
384  *		only for debug after PCC transaction completes.
423 			dev_err(chan->mbox->dev, "failed to register PCC interrupt %d\n",  in pcc_startup()
452  * parse_pcc_subspace - Count PCC subspaces defined
456  * Return: If we find a PCC subspace entry of a valid type, return 0.
459  * This gets called for each entry in the PCC table.
486 			pr_err("Failed to ioremap PCC %s register\n", name);  in pcc_chan_reg_init()
498  * pcc_parse_subspace_irq - Parse the PCC IRQ and PCC ACK register
500  * @pchan: Pointer to the PCC channel info structure.
505  * There should be one entry per PCC channel. This gets called for each
506  * entry in the PCC table. This uses PCCY Type1 structure for all applicable
523 		pr_err("PCC GSI %d not registered\n",  in pcc_parse_subspace_irq()
551 		pr_err("PCC subspace has level IRQ with no ACK register\n");  in pcc_parse_subspace_irq()
559  * pcc_parse_subspace_db_reg - Parse the PCC doorbell register
561  * @pchan: Pointer to the PCC channel info structure.
617  * pcc_parse_subspace_shmem - Parse the PCC Shared Memory Region information
619  * @pchan: Pointer to the PCC channel info structure.
676 			pr_warn("Error parsing PCC subspaces from PCCT\n");  in acpi_pcc_probe()
678 			pr_warn("Invalid PCCT: %d PCC subspaces\n", count);  in acpi_pcc_probe()
737 	/* Point to the first PCC subspace entry */  in pcc_mbox_probe()
776 	pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl->num_chans);  in pcc_mbox_probe()
782 	pr_info("Registering PCC driver as Mailbox controller\n");  in pcc_mbox_probe()
785 		pr_err("Err registering PCC as Mailbox controller: %d\n", rc);  in pcc_mbox_probe()
808 	/* Check if PCC support is available. */  in pcc_init()
812 		pr_debug("ACPI PCC probe failed.\n");  in pcc_init()
820 		pr_debug("Err creating PCC platform bundle\n");  in pcc_init()
829  * Make PCC init postcore so that users of this mailbox