1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * ULCB board CPLD access support
4 *
5 * Copyright (C) 2017 Renesas Electronics Corporation
6 * Copyright (C) 2017 Cogent Embedded, Inc.
7 */
8
9 #include <common.h>
10 #include <asm/gpio.h>
11 #include <asm/io.h>
12 #include <dm.h>
13 #include <errno.h>
14 #include <linux/err.h>
15 #include <sysreset.h>
16
17 #define CPLD_ADDR_MODE 0x00 /* RW */
18 #define CPLD_ADDR_MUX 0x02 /* RW */
19 #define CPLD_ADDR_DIPSW6 0x08 /* R */
20 #define CPLD_ADDR_RESET 0x80 /* RW */
21 #define CPLD_ADDR_VERSION 0xFF /* R */
22
23 struct renesas_ulcb_sysreset_priv {
24 struct gpio_desc miso;
25 struct gpio_desc mosi;
26 struct gpio_desc sck;
27 struct gpio_desc sstbz;
28 };
29
cpld_read(struct udevice * dev,u8 addr)30 static u32 cpld_read(struct udevice *dev, u8 addr)
31 {
32 struct renesas_ulcb_sysreset_priv *priv = dev_get_priv(dev);
33 u32 data = 0;
34 int i;
35
36 for (i = 0; i < 8; i++) {
37 dm_gpio_set_value(&priv->mosi, !!(addr & 0x80)); /* MSB first */
38 dm_gpio_set_value(&priv->sck, 1);
39 addr <<= 1;
40 dm_gpio_set_value(&priv->sck, 0);
41 }
42
43 dm_gpio_set_value(&priv->mosi, 0); /* READ */
44 dm_gpio_set_value(&priv->sstbz, 0);
45 dm_gpio_set_value(&priv->sck, 1);
46 dm_gpio_set_value(&priv->sck, 0);
47 dm_gpio_set_value(&priv->sstbz, 1);
48
49 for (i = 0; i < 32; i++) {
50 dm_gpio_set_value(&priv->sck, 1);
51 data <<= 1;
52 data |= dm_gpio_get_value(&priv->miso); /* MSB first */
53 dm_gpio_set_value(&priv->sck, 0);
54 }
55
56 return data;
57 }
58
cpld_write(struct udevice * dev,u8 addr,u32 data)59 static void cpld_write(struct udevice *dev, u8 addr, u32 data)
60 {
61 struct renesas_ulcb_sysreset_priv *priv = dev_get_priv(dev);
62 int i;
63
64 for (i = 0; i < 32; i++) {
65 dm_gpio_set_value(&priv->mosi, data & (1 << 31)); /* MSB first */
66 dm_gpio_set_value(&priv->sck, 1);
67 data <<= 1;
68 dm_gpio_set_value(&priv->sck, 0);
69 }
70
71 for (i = 0; i < 8; i++) {
72 dm_gpio_set_value(&priv->mosi, addr & 0x80); /* MSB first */
73 dm_gpio_set_value(&priv->sck, 1);
74 addr <<= 1;
75 dm_gpio_set_value(&priv->sck, 0);
76 }
77
78 dm_gpio_set_value(&priv->mosi, 1); /* WRITE */
79 dm_gpio_set_value(&priv->sstbz, 0);
80 dm_gpio_set_value(&priv->sck, 1);
81 dm_gpio_set_value(&priv->sck, 0);
82 dm_gpio_set_value(&priv->sstbz, 1);
83 }
84
do_cpld(cmd_tbl_t * cmdtp,int flag,int argc,char * const argv[])85 static int do_cpld(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
86 {
87 struct udevice *dev;
88 u32 addr, val;
89 int ret;
90
91 ret = uclass_get_device_by_driver(UCLASS_SYSRESET,
92 DM_GET_DRIVER(sysreset_renesas_ulcb),
93 &dev);
94 if (ret)
95 return ret;
96
97 if (argc == 2 && strcmp(argv[1], "info") == 0) {
98 printf("CPLD version:\t\t\t0x%08x\n",
99 cpld_read(dev, CPLD_ADDR_VERSION));
100 printf("H3 Mode setting (MD0..28):\t0x%08x\n",
101 cpld_read(dev, CPLD_ADDR_MODE));
102 printf("Multiplexer settings:\t\t0x%08x\n",
103 cpld_read(dev, CPLD_ADDR_MUX));
104 printf("DIPSW (SW6):\t\t\t0x%08x\n",
105 cpld_read(dev, CPLD_ADDR_DIPSW6));
106 return 0;
107 }
108
109 if (argc < 3)
110 return CMD_RET_USAGE;
111
112 addr = simple_strtoul(argv[2], NULL, 16);
113 if (!(addr == CPLD_ADDR_VERSION || addr == CPLD_ADDR_MODE ||
114 addr == CPLD_ADDR_MUX || addr == CPLD_ADDR_DIPSW6 ||
115 addr == CPLD_ADDR_RESET)) {
116 printf("Invalid CPLD register address\n");
117 return CMD_RET_USAGE;
118 }
119
120 if (argc == 3 && strcmp(argv[1], "read") == 0) {
121 printf("0x%x\n", cpld_read(dev, addr));
122 } else if (argc == 4 && strcmp(argv[1], "write") == 0) {
123 val = simple_strtoul(argv[3], NULL, 16);
124 cpld_write(dev, addr, val);
125 }
126
127 return 0;
128 }
129
130 U_BOOT_CMD(
131 cpld, 4, 1, do_cpld,
132 "CPLD access",
133 "info\n"
134 "cpld read addr\n"
135 "cpld write addr val\n"
136 );
137
renesas_ulcb_sysreset_request(struct udevice * dev,enum sysreset_t type)138 static int renesas_ulcb_sysreset_request(struct udevice *dev, enum sysreset_t type)
139 {
140 cpld_write(dev, CPLD_ADDR_RESET, 1);
141
142 return -EINPROGRESS;
143 }
144
renesas_ulcb_sysreset_probe(struct udevice * dev)145 static int renesas_ulcb_sysreset_probe(struct udevice *dev)
146 {
147 struct renesas_ulcb_sysreset_priv *priv = dev_get_priv(dev);
148
149 if (gpio_request_by_name(dev, "gpio-miso", 0, &priv->miso,
150 GPIOD_IS_IN))
151 return -EINVAL;
152
153 if (gpio_request_by_name(dev, "gpio-sck", 0, &priv->sck,
154 GPIOD_IS_OUT))
155 return -EINVAL;
156
157 if (gpio_request_by_name(dev, "gpio-sstbz", 0, &priv->sstbz,
158 GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE))
159 return -EINVAL;
160
161 if (gpio_request_by_name(dev, "gpio-mosi", 0, &priv->mosi,
162 GPIOD_IS_OUT))
163 return -EINVAL;
164
165 /* PULL-UP on MISO line */
166 setbits_le32(PFC_PUEN5, PUEN_SSI_SDATA4);
167
168 /* Dummy read */
169 cpld_read(dev, CPLD_ADDR_VERSION);
170
171 return 0;
172 }
173
174 static struct sysreset_ops renesas_ulcb_sysreset = {
175 .request = renesas_ulcb_sysreset_request,
176 };
177
178 static const struct udevice_id renesas_ulcb_sysreset_ids[] = {
179 { .compatible = "renesas,ulcb-cpld" },
180 { }
181 };
182
183 U_BOOT_DRIVER(sysreset_renesas_ulcb) = {
184 .name = "renesas_ulcb_sysreset",
185 .id = UCLASS_SYSRESET,
186 .ops = &renesas_ulcb_sysreset,
187 .probe = renesas_ulcb_sysreset_probe,
188 .of_match = renesas_ulcb_sysreset_ids,
189 .priv_auto_alloc_size = sizeof(struct renesas_ulcb_sysreset_priv),
190 };
191