1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2019 Marvell International Ltd.
4  * Copyright (C) 2021 Stefan Roese <sr@denx.de>
5  */
6 
7 #include <dm.h>
8 #include <dm/uclass.h>
9 #include <errno.h>
10 #include <input.h>
11 #include <iomux.h>
12 #include <log.h>
13 #include <serial.h>
14 #include <stdio_dev.h>
15 #include <string.h>
16 #include <watchdog.h>
17 #include <linux/delay.h>
18 #include <asm/addrspace.h>
19 #include <asm/io.h>
20 #include <mach/cvmx-regs.h>
21 #include <mach/cvmx-bootmem.h>
22 
23 #define DRIVER_NAME				"pci-bootcmd"
24 
25 /*
26  * Important:
27  * This address cannot be changed as the PCI console tool relies on exactly
28  * this value!
29  */
30 #define BOOTLOADER_PCI_READ_BUFFER_BASE		0x6c000
31 #define BOOTLOADER_PCI_READ_BUFFER_SIZE		256
32 #define BOOTLOADER_PCI_WRITE_BUFFER_SIZE	256
33 
34 #define BOOTLOADER_PCI_READ_BUFFER_STR_LEN	\
35 	(BOOTLOADER_PCI_READ_BUFFER_SIZE - 8)
36 #define BOOTLOADER_PCI_WRITE_BUFFER_STR_LEN	\
37 	(BOOTLOADER_PCI_WRITE_BUFFER_SIZE - 8)
38 
39 #define BOOTLOADER_PCI_READ_BUFFER_OWNER_ADDR	\
40 	(BOOTLOADER_PCI_READ_BUFFER_BASE + 0)
41 #define BOOTLOADER_PCI_READ_BUFFER_LEN_ADDR	\
42 	(BOOTLOADER_PCI_READ_BUFFER_BASE + 4)
43 #define BOOTLOADER_PCI_READ_BUFFER_DATA_ADDR	\
44 	(BOOTLOADER_PCI_READ_BUFFER_BASE + 8)
45 
46 enum octeon_pci_io_buf_owner {
47 	/* Must be zero, set when memory cleared */
48 	OCTEON_PCI_IO_BUF_OWNER_INVALID = 0,
49 	OCTEON_PCI_IO_BUF_OWNER_OCTEON = 1,
50 	OCTEON_PCI_IO_BUF_OWNER_HOST = 2,
51 };
52 
53 /* Structure for bootloader PCI IO buffers */
54 struct octeon_pci_io_buf {
55 	u32 owner;
56 	u32 len;
57 	char data[0];
58 };
59 
60 struct octeon_bootcmd_priv {
61 	bool started;
62 	int copy_offset;
63 	bool eol;
64 	bool unlocked;
65 	struct octeon_pci_io_buf *buf;
66 };
67 
octeon_bootcmd_pending(struct udevice * dev,bool input)68 static int octeon_bootcmd_pending(struct udevice *dev, bool input)
69 {
70 	struct octeon_bootcmd_priv *priv = dev_get_priv(dev);
71 
72 	if (!input)
73 		return 0;
74 
75 	if (priv->eol)
76 		return 1;
77 
78 	CVMX_SYNC;
79 	if (priv->buf->owner != OCTEON_PCI_IO_BUF_OWNER_OCTEON)
80 		return 0;
81 
82 	if (priv->buf->len > priv->copy_offset &&
83 	    (priv->buf->data[priv->copy_offset] != '\0'))
84 		return 1;
85 
86 	return 0;
87 }
88 
octeon_bootcmd_getc(struct udevice * dev)89 static int octeon_bootcmd_getc(struct udevice *dev)
90 {
91 	struct octeon_bootcmd_priv *priv = dev_get_priv(dev);
92 	char c;
93 
94 	/* There's no EOL for boot commands so we fake it. */
95 	if (priv->eol) {
96 		priv->eol = false;
97 		return '\n';
98 	}
99 
100 	while (!octeon_bootcmd_pending(dev, true)) {
101 		schedule();
102 		/*
103 		 * ToDo:
104 		 * The original code calls octeon_board_poll() here. We may
105 		 * need to implement something similar here.
106 		 */
107 		udelay(100);
108 	}
109 
110 	c = priv->buf->data[priv->copy_offset];
111 	priv->buf->data[priv->copy_offset++] = '\0';
112 
113 	if (priv->copy_offset >= min_t(int, CONFIG_SYS_CBSIZE - 1,
114 				       BOOTLOADER_PCI_READ_BUFFER_STR_LEN - 1) ||
115 	    (priv->buf->data[priv->copy_offset] == '\0')) {
116 		priv->copy_offset = 0;
117 		priv->buf->len = 0;
118 		priv->buf->owner = OCTEON_PCI_IO_BUF_OWNER_HOST;
119 		priv->eol = true;
120 		CVMX_SYNC;
121 	}
122 
123 	return c;
124 }
125 
126 static const struct dm_serial_ops octeon_bootcmd_ops = {
127 	.getc = octeon_bootcmd_getc,
128 	.pending = octeon_bootcmd_pending,
129 };
130 
octeon_bootcmd_probe(struct udevice * dev)131 static int octeon_bootcmd_probe(struct udevice *dev)
132 {
133 	struct octeon_bootcmd_priv *priv = dev_get_priv(dev);
134 
135 	priv->buf = (void *)CKSEG0ADDR(BOOTLOADER_PCI_READ_BUFFER_BASE);
136 	memset(priv->buf, 0, BOOTLOADER_PCI_READ_BUFFER_SIZE);
137 	priv->eol = false;
138 
139 	/*
140 	 * When the bootcmd console is first started it is started as locked to
141 	 * block any calls sending a command until U-Boot is ready to accept
142 	 * commands.  Just before the main loop starts to accept commands the
143 	 * bootcmd console is unlocked.
144 	 */
145 	if (priv->unlocked)
146 		priv->buf->owner = OCTEON_PCI_IO_BUF_OWNER_HOST;
147 	else
148 		priv->buf->owner = OCTEON_PCI_IO_BUF_OWNER_OCTEON;
149 
150 	debug("%s called, buffer ptr: 0x%p, owner: %s\n", __func__,
151 	      priv->buf,
152 	      priv->buf->owner == OCTEON_PCI_IO_BUF_OWNER_HOST ?
153 	      "host" : "octeon");
154 	debug("&priv->copy_offset: 0x%p\n", &priv->copy_offset);
155 	CVMX_SYNC;
156 
157 	/*
158 	 * Perhaps reinvestige this: In the original code, "unlocked" etc
159 	 * is set in the octeon_pci_bootcmd_unlock() function called very
160 	 * late.
161 	 */
162 	priv->buf->owner = OCTEON_PCI_IO_BUF_OWNER_HOST;
163 	priv->unlocked = true;
164 	priv->started = true;
165 	CVMX_SYNC;
166 
167 	return 0;
168 }
169 
170 static const struct udevice_id octeon_bootcmd_serial_id[] = {
171 	{ .compatible = "marvell,pci-bootcmd", },
172 	{ },
173 };
174 
175 U_BOOT_DRIVER(octeon_bootcmd) = {
176 	.name = DRIVER_NAME,
177 	.id = UCLASS_SERIAL,
178 	.ops = &octeon_bootcmd_ops,
179 	.of_match = of_match_ptr(octeon_bootcmd_serial_id),
180 	.probe = octeon_bootcmd_probe,
181 	.priv_auto = sizeof(struct octeon_bootcmd_priv),
182 };
183