1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2012
4  * Valentin Lontgchamp, Keymile AG, valentin.longchamp@keymile.com
5  */
6 
7 #include <common.h>
8 #include <i2c.h>
9 #include <linux/errno.h>
10 
11 /* GPIO Pin from kirkwood connected to PROGRAM_B pin of the xilinx FPGA */
12 #define KM_XLX_PROGRAM_B_PIN    39
13 
14 #define BOCO_ADDR	0x10
15 
16 #define ID_REG		0x00
17 #define BOCO2_ID	0x5b
18 
19 static int check_boco2(void)
20 {
21 	int ret;
22 	u8 id;
23 
24 	ret = i2c_read(BOCO_ADDR, ID_REG, 1, &id, 1);
25 	if (ret) {
26 		printf("%s: error reading the BOCO id !!\n", __func__);
27 		return ret;
28 	}
29 
30 	return (id == BOCO2_ID);
31 }
32 
33 static int boco_clear_bits(u8 reg, u8 flags)
34 {
35 	int ret;
36 	u8 regval;
37 
38 	/* give access to the EEPROM from FPGA */
39 	ret = i2c_read(BOCO_ADDR, reg, 1, &regval, 1);
40 	if (ret) {
41 		printf("%s: error reading the BOCO @%#x !!\n",
42 			__func__, reg);
43 		return ret;
44 	}
45 	regval &= ~flags;
46 	ret = i2c_write(BOCO_ADDR, reg, 1, &regval, 1);
47 	if (ret) {
48 		printf("%s: error writing the BOCO @%#x !!\n",
49 			__func__, reg);
50 		return ret;
51 	}
52 
53 	return 0;
54 }
55 
56 static int boco_set_bits(u8 reg, u8 flags)
57 {
58 	int ret;
59 	u8 regval;
60 
61 	/* give access to the EEPROM from FPGA */
62 	ret = i2c_read(BOCO_ADDR, reg, 1, &regval, 1);
63 	if (ret) {
64 		printf("%s: error reading the BOCO @%#x !!\n",
65 			__func__, reg);
66 		return ret;
67 	}
68 	regval |= flags;
69 	ret = i2c_write(BOCO_ADDR, reg, 1, &regval, 1);
70 	if (ret) {
71 		printf("%s: error writing the BOCO @%#x !!\n",
72 			__func__, reg);
73 		return ret;
74 	}
75 
76 	return 0;
77 }
78 
79 #define SPI_REG		0x06
80 #define CFG_EEPROM	0x02
81 #define FPGA_PROG	0x04
82 #define FPGA_INIT_B	0x10
83 #define FPGA_DONE	0x20
84 
85 static int fpga_done(void)
86 {
87 	int ret = 0;
88 	u8 regval;
89 
90 	/* this is only supported with the boco2 design */
91 	if (!check_boco2())
92 		return 0;
93 
94 	ret = i2c_read(BOCO_ADDR, SPI_REG, 1, &regval, 1);
95 	if (ret) {
96 		printf("%s: error reading the BOCO @%#x !!\n",
97 			__func__, SPI_REG);
98 		return 0;
99 	}
100 
101 	return regval & FPGA_DONE ? 1 : 0;
102 }
103 
104 int skip;
105 
106 int trigger_fpga_config(void)
107 {
108 	int ret = 0;
109 
110 	/* if the FPGA is already configured, we do not want to
111 	 * reconfigure it */
112 	skip = 0;
113 	if (fpga_done()) {
114 		printf("PCIe FPGA config: skipped\n");
115 		skip = 1;
116 		return 0;
117 	}
118 
119 	if (check_boco2()) {
120 		/* we have a BOCO2, this has to be triggered here */
121 
122 		/* make sure the FPGA_can access the EEPROM */
123 		ret = boco_clear_bits(SPI_REG, CFG_EEPROM);
124 		if (ret)
125 			return ret;
126 
127 		/* trigger the config start */
128 		ret = boco_clear_bits(SPI_REG, FPGA_PROG | FPGA_INIT_B);
129 		if (ret)
130 			return ret;
131 
132 		/* small delay for the pulse */
133 		udelay(10);
134 
135 		/* up signal for pulse end */
136 		ret = boco_set_bits(SPI_REG, FPGA_PROG);
137 		if (ret)
138 			return ret;
139 
140 		/* finally, raise INIT_B to remove the config delay */
141 		ret = boco_set_bits(SPI_REG, FPGA_INIT_B);
142 		if (ret)
143 			return ret;
144 
145 	} else {
146 		/* we do it the old way, with the gpio pin */
147 		kw_gpio_set_valid(KM_XLX_PROGRAM_B_PIN, 1);
148 		kw_gpio_direction_output(KM_XLX_PROGRAM_B_PIN, 0);
149 		/* small delay for the pulse */
150 		udelay(10);
151 		kw_gpio_direction_input(KM_XLX_PROGRAM_B_PIN);
152 	}
153 
154 	return 0;
155 }
156 
157 int wait_for_fpga_config(void)
158 {
159 	int ret = 0;
160 	u8 spictrl;
161 	u32 timeout = 20000;
162 
163 	if (skip)
164 		return 0;
165 
166 	if (!check_boco2()) {
167 		/* we do not have BOCO2, this is not really used */
168 		return 0;
169 	}
170 
171 	printf("PCIe FPGA config:");
172 	do {
173 		ret = i2c_read(BOCO_ADDR, SPI_REG, 1, &spictrl, 1);
174 		if (ret) {
175 			printf("%s: error reading the BOCO spictrl !!\n",
176 				__func__);
177 			return ret;
178 		}
179 		if (timeout-- == 0) {
180 			printf(" FPGA_DONE timeout\n");
181 			return -EFAULT;
182 		}
183 		udelay(10);
184 	} while (!(spictrl & FPGA_DONE));
185 
186 	printf(" done\n");
187 
188 	return 0;
189 }
190 
191 #if defined(KM_PCIE_RESET_MPP7)
192 
193 #define KM_PEX_RST_GPIO_PIN	7
194 int fpga_reset(void)
195 {
196 	if (!check_boco2()) {
197 		/* we do not have BOCO2, this is not really used */
198 		return 0;
199 	}
200 
201 	printf("PCIe reset through GPIO7: ");
202 	/* apply PCIe reset via GPIO */
203 	kw_gpio_set_valid(KM_PEX_RST_GPIO_PIN, 1);
204 	kw_gpio_direction_output(KM_PEX_RST_GPIO_PIN, 1);
205 	kw_gpio_set_value(KM_PEX_RST_GPIO_PIN, 0);
206 	udelay(1000*10);
207 	kw_gpio_set_value(KM_PEX_RST_GPIO_PIN, 1);
208 
209 	printf(" done\n");
210 
211 	return 0;
212 }
213 
214 #else
215 
216 #define PRST1		0x4
217 #define PCIE_RST	0x10
218 #define TRAFFIC_RST	0x04
219 
220 int fpga_reset(void)
221 {
222 	int ret = 0;
223 	u8 resets;
224 
225 	if (!check_boco2()) {
226 		/* we do not have BOCO2, this is not really used */
227 		return 0;
228 	}
229 
230 	/* if we have skipped, we only want to reset the PCIe part */
231 	resets = skip ? PCIE_RST : PCIE_RST | TRAFFIC_RST;
232 
233 	ret = boco_clear_bits(PRST1, resets);
234 	if (ret)
235 		return ret;
236 
237 	/* small delay for the pulse */
238 	udelay(10);
239 
240 	ret = boco_set_bits(PRST1, resets);
241 	if (ret)
242 		return ret;
243 
244 	return 0;
245 }
246 #endif
247 
248 /* the FPGA was configured, we configure the BOCO2 so that the EEPROM
249  * is available from the Bobcat SPI bus */
250 int toggle_eeprom_spi_bus(void)
251 {
252 	int ret = 0;
253 
254 	if (!check_boco2()) {
255 		/* we do not have BOCO2, this is not really used */
256 		return 0;
257 	}
258 
259 	ret = boco_set_bits(SPI_REG, CFG_EEPROM);
260 	if (ret)
261 		return ret;
262 
263 	return 0;
264 }
265