xref: /optee_os/core/include/drivers/serial.h (revision 78b7c7c7653f8bff42fe44d31a79d7f6bbfd4d47)
1 /* SPDX-License-Identifier: BSD-2-Clause */
2 /*
3  * Copyright (c) 2016, Linaro Limited
4  * All rights reserved.
5  */
6 #ifndef __DRIVERS_SERIAL_H
7 #define __DRIVERS_SERIAL_H
8 
9 #include <assert.h>
10 #include <stdbool.h>
11 #include <types_ext.h>
12 #include <mm/core_memprot.h>
13 #include <mm/core_mmu.h>
14 
15 struct serial_chip {
16 	const struct serial_ops *ops;
17 };
18 
19 struct serial_ops {
20 	void (*putc)(struct serial_chip *chip, int ch);
21 	void (*flush)(struct serial_chip *chip);
22 	bool (*have_rx_data)(struct serial_chip *chip);
23 	int (*getchar)(struct serial_chip *chip);
24 };
25 
26 struct serial_driver {
27 	/* Allocate device data and return the inner serial_chip */
28 	struct serial_chip *(*dev_alloc)(void);
29 	/*
30 	 * Initialize device from FDT node. @parms is device-specific,
31 	 * its meaning is as defined by the DT bindings for the characters
32 	 * following the ":" in /chosen/stdout-path. Typically for UART
33 	 * devices this is <baud>{<parity>{<bits>{<flow>}}} where:
34 	 *   baud   - baud rate in decimal
35 	 *   parity - 'n' (none), 'o', (odd) or 'e' (even)
36 	 *   bits   - number of data bits
37 	 *   flow   - 'r' (rts)
38 	 * For example: 115200n8r
39 	 */
40 	int (*dev_init)(struct serial_chip *dev, const void *fdt,
41 			int offset, const char *parms);
42 	void (*dev_free)(struct serial_chip *dev);
43 };
44 
45 struct io_pa_va {
46 	paddr_t pa;
47 	vaddr_t va;
48 };
49 
50 /*
51  * Helper function to return a physical or virtual address for a device,
52  * depending on whether the MMU is enabled or not
53  */
54 static inline vaddr_t io_pa_or_va(struct io_pa_va *p)
55 {
56 	assert(p->pa);
57 	if (cpu_mmu_enabled()) {
58 		if (!p->va)
59 			p->va = (vaddr_t)phys_to_virt_io(p->pa);
60 		assert(p->va);
61 		return p->va;
62 	}
63 	return p->pa;
64 }
65 
66 #endif /*__DRIVERS_SERIASERIAL_H*/
67