1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2012 Stefan Roese <sr@denx.de>
4 */
5
6 #include <linux/device.h>
7 #include <linux/firmware.h>
8 #include <linux/module.h>
9 #include <linux/errno.h>
10 #include <linux/kernel.h>
11 #include <linux/spi/spi.h>
12 #include <linux/platform_device.h>
13 #include <linux/delay.h>
14 #include <asm/unaligned.h>
15
16 #define FIRMWARE_NAME "lattice-ecp3.bit"
17
18 /*
19 * The JTAG ID's of the supported FPGA's. The ID is 32bit wide
20 * reversed as noted in the manual.
21 */
22 #define ID_ECP3_17 0xc2088080
23 #define ID_ECP3_35 0xc2048080
24
25 /* FPGA commands */
26 #define FPGA_CMD_READ_ID 0x07 /* plus 24 bits */
27 #define FPGA_CMD_READ_STATUS 0x09 /* plus 24 bits */
28 #define FPGA_CMD_CLEAR 0x70
29 #define FPGA_CMD_REFRESH 0x71
30 #define FPGA_CMD_WRITE_EN 0x4a /* plus 2 bits */
31 #define FPGA_CMD_WRITE_DIS 0x4f /* plus 8 bits */
32 #define FPGA_CMD_WRITE_INC 0x41 /* plus 0 bits */
33
34 /*
35 * The status register is 32bit revered, DONE is bit 17 from the TN1222.pdf
36 * (LatticeECP3 Slave SPI Port User's Guide)
37 */
38 #define FPGA_STATUS_DONE 0x00004000
39 #define FPGA_STATUS_CLEARED 0x00010000
40
41 #define FPGA_CLEAR_TIMEOUT 5000 /* max. 5000ms for FPGA clear */
42 #define FPGA_CLEAR_MSLEEP 10
43 #define FPGA_CLEAR_LOOP_COUNT (FPGA_CLEAR_TIMEOUT / FPGA_CLEAR_MSLEEP)
44
45 struct fpga_data {
46 struct completion fw_loaded;
47 };
48
49 struct ecp3_dev {
50 u32 jedec_id;
51 char *name;
52 };
53
54 static const struct ecp3_dev ecp3_dev[] = {
55 {
56 .jedec_id = ID_ECP3_17,
57 .name = "Lattice ECP3-17",
58 },
59 {
60 .jedec_id = ID_ECP3_35,
61 .name = "Lattice ECP3-35",
62 },
63 };
64
firmware_load(const struct firmware * fw,void * context)65 static void firmware_load(const struct firmware *fw, void *context)
66 {
67 struct spi_device *spi = (struct spi_device *)context;
68 struct fpga_data *data = spi_get_drvdata(spi);
69 u8 *buffer;
70 u8 txbuf[8];
71 u8 rxbuf[8];
72 int rx_len = 8;
73 int i;
74 u32 jedec_id;
75 u32 status;
76
77 if (fw == NULL) {
78 dev_err(&spi->dev, "Cannot load firmware, aborting\n");
79 goto out;
80 }
81
82 if (fw->size == 0) {
83 dev_err(&spi->dev, "Error: Firmware size is 0!\n");
84 goto out;
85 }
86
87 /* Fill dummy data (24 stuffing bits for commands) */
88 txbuf[1] = 0x00;
89 txbuf[2] = 0x00;
90 txbuf[3] = 0x00;
91
92 /* Trying to speak with the FPGA via SPI... */
93 txbuf[0] = FPGA_CMD_READ_ID;
94 spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
95 jedec_id = get_unaligned_be32(&rxbuf[4]);
96 dev_dbg(&spi->dev, "FPGA JTAG ID=%08x\n", jedec_id);
97
98 for (i = 0; i < ARRAY_SIZE(ecp3_dev); i++) {
99 if (jedec_id == ecp3_dev[i].jedec_id)
100 break;
101 }
102 if (i == ARRAY_SIZE(ecp3_dev)) {
103 dev_err(&spi->dev,
104 "Error: No supported FPGA detected (JEDEC_ID=%08x)!\n",
105 jedec_id);
106 goto out;
107 }
108
109 dev_info(&spi->dev, "FPGA %s detected\n", ecp3_dev[i].name);
110
111 txbuf[0] = FPGA_CMD_READ_STATUS;
112 spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
113 status = get_unaligned_be32(&rxbuf[4]);
114 dev_dbg(&spi->dev, "FPGA Status=%08x\n", status);
115
116 buffer = kzalloc(fw->size + 8, GFP_KERNEL);
117 if (!buffer) {
118 dev_err(&spi->dev, "Error: Can't allocate memory!\n");
119 goto out;
120 }
121
122 /*
123 * Insert WRITE_INC command into stream (one SPI frame)
124 */
125 buffer[0] = FPGA_CMD_WRITE_INC;
126 buffer[1] = 0xff;
127 buffer[2] = 0xff;
128 buffer[3] = 0xff;
129 memcpy(buffer + 4, fw->data, fw->size);
130
131 txbuf[0] = FPGA_CMD_REFRESH;
132 spi_write(spi, txbuf, 4);
133
134 txbuf[0] = FPGA_CMD_WRITE_EN;
135 spi_write(spi, txbuf, 4);
136
137 txbuf[0] = FPGA_CMD_CLEAR;
138 spi_write(spi, txbuf, 4);
139
140 /*
141 * Wait for FPGA memory to become cleared
142 */
143 for (i = 0; i < FPGA_CLEAR_LOOP_COUNT; i++) {
144 txbuf[0] = FPGA_CMD_READ_STATUS;
145 spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
146 status = get_unaligned_be32(&rxbuf[4]);
147 if (status == FPGA_STATUS_CLEARED)
148 break;
149
150 msleep(FPGA_CLEAR_MSLEEP);
151 }
152
153 if (i == FPGA_CLEAR_LOOP_COUNT) {
154 dev_err(&spi->dev,
155 "Error: Timeout waiting for FPGA to clear (status=%08x)!\n",
156 status);
157 kfree(buffer);
158 goto out;
159 }
160
161 dev_info(&spi->dev, "Configuring the FPGA...\n");
162 spi_write(spi, buffer, fw->size + 8);
163
164 txbuf[0] = FPGA_CMD_WRITE_DIS;
165 spi_write(spi, txbuf, 4);
166
167 txbuf[0] = FPGA_CMD_READ_STATUS;
168 spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
169 status = get_unaligned_be32(&rxbuf[4]);
170 dev_dbg(&spi->dev, "FPGA Status=%08x\n", status);
171
172 /* Check result */
173 if (status & FPGA_STATUS_DONE)
174 dev_info(&spi->dev, "FPGA successfully configured!\n");
175 else
176 dev_info(&spi->dev, "FPGA not configured (DONE not set)\n");
177
178 /*
179 * Don't forget to release the firmware again
180 */
181 release_firmware(fw);
182
183 kfree(buffer);
184 out:
185 complete(&data->fw_loaded);
186 }
187
lattice_ecp3_probe(struct spi_device * spi)188 static int lattice_ecp3_probe(struct spi_device *spi)
189 {
190 struct fpga_data *data;
191 int err;
192
193 data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
194 if (!data) {
195 dev_err(&spi->dev, "Memory allocation for fpga_data failed\n");
196 return -ENOMEM;
197 }
198 spi_set_drvdata(spi, data);
199
200 init_completion(&data->fw_loaded);
201 err = request_firmware_nowait(THIS_MODULE, FW_ACTION_UEVENT,
202 FIRMWARE_NAME, &spi->dev,
203 GFP_KERNEL, spi, firmware_load);
204 if (err) {
205 dev_err(&spi->dev, "Firmware loading failed with %d!\n", err);
206 return err;
207 }
208
209 dev_info(&spi->dev, "FPGA bitstream configuration driver registered\n");
210
211 return 0;
212 }
213
lattice_ecp3_remove(struct spi_device * spi)214 static void lattice_ecp3_remove(struct spi_device *spi)
215 {
216 struct fpga_data *data = spi_get_drvdata(spi);
217
218 wait_for_completion(&data->fw_loaded);
219 }
220
221 static const struct spi_device_id lattice_ecp3_id[] = {
222 { "ecp3-17", 0 },
223 { "ecp3-35", 0 },
224 { }
225 };
226 MODULE_DEVICE_TABLE(spi, lattice_ecp3_id);
227
228 static struct spi_driver lattice_ecp3_driver = {
229 .driver = {
230 .name = "lattice-ecp3",
231 },
232 .probe = lattice_ecp3_probe,
233 .remove = lattice_ecp3_remove,
234 .id_table = lattice_ecp3_id,
235 };
236
237 module_spi_driver(lattice_ecp3_driver);
238
239 MODULE_AUTHOR("Stefan Roese <sr@denx.de>");
240 MODULE_DESCRIPTION("Lattice ECP3 FPGA configuration via SPI");
241 MODULE_LICENSE("GPL");
242 MODULE_FIRMWARE(FIRMWARE_NAME);
243
