1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Lattice FPGA programming over slave SPI sysCONFIG interface.
4 */
5
6 #include <linux/spi/spi.h>
7
8 #include "lattice-sysconfig.h"
9
10 static const u32 ecp5_spi_max_speed_hz = 60000000;
11
sysconfig_spi_cmd_transfer(struct sysconfig_priv * priv,const void * tx_buf,size_t tx_len,void * rx_buf,size_t rx_len)12 static int sysconfig_spi_cmd_transfer(struct sysconfig_priv *priv,
13 const void *tx_buf, size_t tx_len,
14 void *rx_buf, size_t rx_len)
15 {
16 struct spi_device *spi = to_spi_device(priv->dev);
17
18 return spi_write_then_read(spi, tx_buf, tx_len, rx_buf, rx_len);
19 }
20
sysconfig_spi_bitstream_burst_init(struct sysconfig_priv * priv)21 static int sysconfig_spi_bitstream_burst_init(struct sysconfig_priv *priv)
22 {
23 const u8 lsc_bitstream_burst[] = SYSCONFIG_LSC_BITSTREAM_BURST;
24 struct spi_device *spi = to_spi_device(priv->dev);
25 struct spi_transfer xfer = {};
26 struct spi_message msg;
27 size_t buf_len;
28 void *buf;
29 int ret;
30
31 buf_len = sizeof(lsc_bitstream_burst);
32
33 buf = kmemdup(lsc_bitstream_burst, buf_len, GFP_KERNEL);
34 if (!buf)
35 return -ENOMEM;
36
37 xfer.len = buf_len;
38 xfer.tx_buf = buf;
39 xfer.cs_change = 1;
40
41 spi_message_init_with_transfers(&msg, &xfer, 1);
42
43 /*
44 * Lock SPI bus for exclusive usage until FPGA programming is done.
45 * SPI bus will be released in sysconfig_spi_bitstream_burst_complete().
46 */
47 spi_bus_lock(spi->controller);
48
49 ret = spi_sync_locked(spi, &msg);
50 if (ret)
51 spi_bus_unlock(spi->controller);
52
53 kfree(buf);
54
55 return ret;
56 }
57
sysconfig_spi_bitstream_burst_write(struct sysconfig_priv * priv,const char * buf,size_t len)58 static int sysconfig_spi_bitstream_burst_write(struct sysconfig_priv *priv,
59 const char *buf, size_t len)
60 {
61 struct spi_device *spi = to_spi_device(priv->dev);
62 struct spi_transfer xfer = {
63 .tx_buf = buf,
64 .len = len,
65 .cs_change = 1,
66 };
67 struct spi_message msg;
68
69 spi_message_init_with_transfers(&msg, &xfer, 1);
70
71 return spi_sync_locked(spi, &msg);
72 }
73
sysconfig_spi_bitstream_burst_complete(struct sysconfig_priv * priv)74 static int sysconfig_spi_bitstream_burst_complete(struct sysconfig_priv *priv)
75 {
76 struct spi_device *spi = to_spi_device(priv->dev);
77
78 /* Bitstream burst write is done, release SPI bus */
79 spi_bus_unlock(spi->controller);
80
81 /* Toggle CS to finish bitstream write */
82 return spi_write(spi, NULL, 0);
83 }
84
sysconfig_spi_probe(struct spi_device * spi)85 static int sysconfig_spi_probe(struct spi_device *spi)
86 {
87 const struct spi_device_id *dev_id;
88 struct device *dev = &spi->dev;
89 struct sysconfig_priv *priv;
90 const u32 *spi_max_speed;
91
92 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
93 if (!priv)
94 return -ENOMEM;
95
96 spi_max_speed = device_get_match_data(dev);
97 if (!spi_max_speed) {
98 dev_id = spi_get_device_id(spi);
99 if (!dev_id)
100 return -ENODEV;
101
102 spi_max_speed = (const u32 *)dev_id->driver_data;
103 }
104
105 if (!spi_max_speed)
106 return -EINVAL;
107
108 if (spi->max_speed_hz > *spi_max_speed) {
109 dev_err(dev, "SPI speed %u is too high, maximum speed is %u\n",
110 spi->max_speed_hz, *spi_max_speed);
111 return -EINVAL;
112 }
113
114 priv->dev = dev;
115 priv->command_transfer = sysconfig_spi_cmd_transfer;
116 priv->bitstream_burst_write_init = sysconfig_spi_bitstream_burst_init;
117 priv->bitstream_burst_write = sysconfig_spi_bitstream_burst_write;
118 priv->bitstream_burst_write_complete = sysconfig_spi_bitstream_burst_complete;
119
120 return sysconfig_probe(priv);
121 }
122
123 static const struct spi_device_id sysconfig_spi_ids[] = {
124 {
125 .name = "sysconfig-ecp5",
126 .driver_data = (kernel_ulong_t)&ecp5_spi_max_speed_hz,
127 }, {},
128 };
129 MODULE_DEVICE_TABLE(spi, sysconfig_spi_ids);
130
131 #if IS_ENABLED(CONFIG_OF)
132 static const struct of_device_id sysconfig_of_ids[] = {
133 {
134 .compatible = "lattice,sysconfig-ecp5",
135 .data = &ecp5_spi_max_speed_hz,
136 }, {},
137 };
138 MODULE_DEVICE_TABLE(of, sysconfig_of_ids);
139 #endif /* IS_ENABLED(CONFIG_OF) */
140
141 static struct spi_driver lattice_sysconfig_driver = {
142 .probe = sysconfig_spi_probe,
143 .id_table = sysconfig_spi_ids,
144 .driver = {
145 .name = "lattice_sysconfig_spi_fpga_mgr",
146 .of_match_table = of_match_ptr(sysconfig_of_ids),
147 },
148 };
149 module_spi_driver(lattice_sysconfig_driver);
150
151 MODULE_DESCRIPTION("Lattice sysCONFIG Slave SPI FPGA Manager");
152 MODULE_LICENSE("GPL");
153