1 /*
2  * (C) Copyright 2012
3  * Valentin Lontgchamp, Keymile AG, valentin.longchamp@keymile.com
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <i2c.h>
10 #include <linux/errno.h>
11 
12 /* GPIO Pin from kirkwood connected to PROGRAM_B pin of the xilinx FPGA */
13 #define KM_XLX_PROGRAM_B_PIN    39
14 
15 #define BOCO_ADDR	0x10
16 
17 #define ID_REG		0x00
18 #define BOCO2_ID	0x5b
19 
20 static int check_boco2(void)
21 {
22 	int ret;
23 	u8 id;
24 
25 	ret = i2c_read(BOCO_ADDR, ID_REG, 1, &id, 1);
26 	if (ret) {
27 		printf("%s: error reading the BOCO id !!\n", __func__);
28 		return ret;
29 	}
30 
31 	return (id == BOCO2_ID);
32 }
33 
34 static int boco_clear_bits(u8 reg, u8 flags)
35 {
36 	int ret;
37 	u8 regval;
38 
39 	/* give access to the EEPROM from FPGA */
40 	ret = i2c_read(BOCO_ADDR, reg, 1, &regval, 1);
41 	if (ret) {
42 		printf("%s: error reading the BOCO @%#x !!\n",
43 			__func__, reg);
44 		return ret;
45 	}
46 	regval &= ~flags;
47 	ret = i2c_write(BOCO_ADDR, reg, 1, &regval, 1);
48 	if (ret) {
49 		printf("%s: error writing the BOCO @%#x !!\n",
50 			__func__, reg);
51 		return ret;
52 	}
53 
54 	return 0;
55 }
56 
57 static int boco_set_bits(u8 reg, u8 flags)
58 {
59 	int ret;
60 	u8 regval;
61 
62 	/* give access to the EEPROM from FPGA */
63 	ret = i2c_read(BOCO_ADDR, reg, 1, &regval, 1);
64 	if (ret) {
65 		printf("%s: error reading the BOCO @%#x !!\n",
66 			__func__, reg);
67 		return ret;
68 	}
69 	regval |= flags;
70 	ret = i2c_write(BOCO_ADDR, reg, 1, &regval, 1);
71 	if (ret) {
72 		printf("%s: error writing the BOCO @%#x !!\n",
73 			__func__, reg);
74 		return ret;
75 	}
76 
77 	return 0;
78 }
79 
80 #define SPI_REG		0x06
81 #define CFG_EEPROM	0x02
82 #define FPGA_PROG	0x04
83 #define FPGA_INIT_B	0x10
84 #define FPGA_DONE	0x20
85 
86 static int fpga_done(void)
87 {
88 	int ret = 0;
89 	u8 regval;
90 
91 	/* this is only supported with the boco2 design */
92 	if (!check_boco2())
93 		return 0;
94 
95 	ret = i2c_read(BOCO_ADDR, SPI_REG, 1, &regval, 1);
96 	if (ret) {
97 		printf("%s: error reading the BOCO @%#x !!\n",
98 			__func__, SPI_REG);
99 		return 0;
100 	}
101 
102 	return regval & FPGA_DONE ? 1 : 0;
103 }
104 
105 int skip;
106 
107 int trigger_fpga_config(void)
108 {
109 	int ret = 0;
110 
111 	/* if the FPGA is already configured, we do not want to
112 	 * reconfigure it */
113 	skip = 0;
114 	if (fpga_done()) {
115 		printf("PCIe FPGA config: skipped\n");
116 		skip = 1;
117 		return 0;
118 	}
119 
120 	if (check_boco2()) {
121 		/* we have a BOCO2, this has to be triggered here */
122 
123 		/* make sure the FPGA_can access the EEPROM */
124 		ret = boco_clear_bits(SPI_REG, CFG_EEPROM);
125 		if (ret)
126 			return ret;
127 
128 		/* trigger the config start */
129 		ret = boco_clear_bits(SPI_REG, FPGA_PROG | FPGA_INIT_B);
130 		if (ret)
131 			return ret;
132 
133 		/* small delay for the pulse */
134 		udelay(10);
135 
136 		/* up signal for pulse end */
137 		ret = boco_set_bits(SPI_REG, FPGA_PROG);
138 		if (ret)
139 			return ret;
140 
141 		/* finally, raise INIT_B to remove the config delay */
142 		ret = boco_set_bits(SPI_REG, FPGA_INIT_B);
143 		if (ret)
144 			return ret;
145 
146 	} else {
147 		/* we do it the old way, with the gpio pin */
148 		kw_gpio_set_valid(KM_XLX_PROGRAM_B_PIN, 1);
149 		kw_gpio_direction_output(KM_XLX_PROGRAM_B_PIN, 0);
150 		/* small delay for the pulse */
151 		udelay(10);
152 		kw_gpio_direction_input(KM_XLX_PROGRAM_B_PIN);
153 	}
154 
155 	return 0;
156 }
157 
158 int wait_for_fpga_config(void)
159 {
160 	int ret = 0;
161 	u8 spictrl;
162 	u32 timeout = 20000;
163 
164 	if (skip)
165 		return 0;
166 
167 	if (!check_boco2()) {
168 		/* we do not have BOCO2, this is not really used */
169 		return 0;
170 	}
171 
172 	printf("PCIe FPGA config:");
173 	do {
174 		ret = i2c_read(BOCO_ADDR, SPI_REG, 1, &spictrl, 1);
175 		if (ret) {
176 			printf("%s: error reading the BOCO spictrl !!\n",
177 				__func__);
178 			return ret;
179 		}
180 		if (timeout-- == 0) {
181 			printf(" FPGA_DONE timeout\n");
182 			return -EFAULT;
183 		}
184 		udelay(10);
185 	} while (!(spictrl & FPGA_DONE));
186 
187 	printf(" done\n");
188 
189 	return 0;
190 }
191 
192 #if defined(KM_PCIE_RESET_MPP7)
193 
194 #define KM_PEX_RST_GPIO_PIN	7
195 int fpga_reset(void)
196 {
197 	if (!check_boco2()) {
198 		/* we do not have BOCO2, this is not really used */
199 		return 0;
200 	}
201 
202 	printf("PCIe reset through GPIO7: ");
203 	/* apply PCIe reset via GPIO */
204 	kw_gpio_set_valid(KM_PEX_RST_GPIO_PIN, 1);
205 	kw_gpio_direction_output(KM_PEX_RST_GPIO_PIN, 1);
206 	kw_gpio_set_value(KM_PEX_RST_GPIO_PIN, 0);
207 	udelay(1000*10);
208 	kw_gpio_set_value(KM_PEX_RST_GPIO_PIN, 1);
209 
210 	printf(" done\n");
211 
212 	return 0;
213 }
214 
215 #else
216 
217 #define PRST1		0x4
218 #define PCIE_RST	0x10
219 #define TRAFFIC_RST	0x04
220 
221 int fpga_reset(void)
222 {
223 	int ret = 0;
224 	u8 resets;
225 
226 	if (!check_boco2()) {
227 		/* we do not have BOCO2, this is not really used */
228 		return 0;
229 	}
230 
231 	/* if we have skipped, we only want to reset the PCIe part */
232 	resets = skip ? PCIE_RST : PCIE_RST | TRAFFIC_RST;
233 
234 	ret = boco_clear_bits(PRST1, resets);
235 	if (ret)
236 		return ret;
237 
238 	/* small delay for the pulse */
239 	udelay(10);
240 
241 	ret = boco_set_bits(PRST1, resets);
242 	if (ret)
243 		return ret;
244 
245 	return 0;
246 }
247 #endif
248 
249 /* the FPGA was configured, we configure the BOCO2 so that the EEPROM
250  * is available from the Bobcat SPI bus */
251 int toggle_eeprom_spi_bus(void)
252 {
253 	int ret = 0;
254 
255 	if (!check_boco2()) {
256 		/* we do not have BOCO2, this is not really used */
257 		return 0;
258 	}
259 
260 	ret = boco_set_bits(SPI_REG, CFG_EEPROM);
261 	if (ret)
262 		return ret;
263 
264 	return 0;
265 }
266