2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 2011, 2012 Cavium, Inc.
9 #include <linux/platform_device.h>
10 #include <linux/interrupt.h>
11 #include <linux/spi/spi.h>
12 #include <linux/module.h>
13 #include <linux/delay.h>
14 #include <linux/init.h>
18 #include <asm/octeon/octeon.h>
19 #include <asm/octeon/cvmx-mpi-defs.h>
21 #define OCTEON_SPI_CFG 0
22 #define OCTEON_SPI_STS 0x08
23 #define OCTEON_SPI_TX 0x10
24 #define OCTEON_SPI_DAT0 0x80
26 #define OCTEON_SPI_MAX_BYTES 9
28 #define OCTEON_SPI_MAX_CLOCK_HZ 16000000
36 static void octeon_spi_wait_ready(struct octeon_spi *p)
38 union cvmx_mpi_sts mpi_sts;
39 unsigned int loops = 0;
44 mpi_sts.u64 = cvmx_read_csr(p->register_base + OCTEON_SPI_STS);
45 } while (mpi_sts.s.busy);
48 static int octeon_spi_do_transfer(struct octeon_spi *p,
49 struct spi_message *msg,
50 struct spi_transfer *xfer,
53 struct spi_device *spi = msg->spi;
54 union cvmx_mpi_cfg mpi_cfg;
55 union cvmx_mpi_tx mpi_tx;
57 unsigned int speed_hz;
66 cpha = mode & SPI_CPHA;
67 cpol = mode & SPI_CPOL;
69 speed_hz = xfer->speed_hz ? : spi->max_speed_hz;
70 if (speed_hz > OCTEON_SPI_MAX_CLOCK_HZ)
71 speed_hz = OCTEON_SPI_MAX_CLOCK_HZ;
73 clkdiv = octeon_get_io_clock_rate() / (2 * speed_hz);
77 mpi_cfg.s.clkdiv = clkdiv;
78 mpi_cfg.s.cshi = (mode & SPI_CS_HIGH) ? 1 : 0;
79 mpi_cfg.s.lsbfirst = (mode & SPI_LSB_FIRST) ? 1 : 0;
80 mpi_cfg.s.wireor = (mode & SPI_3WIRE) ? 1 : 0;
81 mpi_cfg.s.idlelo = cpha != cpol;
82 mpi_cfg.s.cslate = cpha ? 1 : 0;
85 if (spi->chip_select < 4)
86 p->cs_enax |= 1ull << (12 + spi->chip_select);
87 mpi_cfg.u64 |= p->cs_enax;
89 if (mpi_cfg.u64 != p->last_cfg) {
90 p->last_cfg = mpi_cfg.u64;
91 cvmx_write_csr(p->register_base + OCTEON_SPI_CFG, mpi_cfg.u64);
93 tx_buf = xfer->tx_buf;
94 rx_buf = xfer->rx_buf;
96 while (len > OCTEON_SPI_MAX_BYTES) {
97 for (i = 0; i < OCTEON_SPI_MAX_BYTES; i++) {
103 cvmx_write_csr(p->register_base + OCTEON_SPI_DAT0 + (8 * i), d);
106 mpi_tx.s.csid = spi->chip_select;
107 mpi_tx.s.leavecs = 1;
108 mpi_tx.s.txnum = tx_buf ? OCTEON_SPI_MAX_BYTES : 0;
109 mpi_tx.s.totnum = OCTEON_SPI_MAX_BYTES;
110 cvmx_write_csr(p->register_base + OCTEON_SPI_TX, mpi_tx.u64);
112 octeon_spi_wait_ready(p);
114 for (i = 0; i < OCTEON_SPI_MAX_BYTES; i++) {
115 u64 v = cvmx_read_csr(p->register_base + OCTEON_SPI_DAT0 + (8 * i));
118 len -= OCTEON_SPI_MAX_BYTES;
121 for (i = 0; i < len; i++) {
127 cvmx_write_csr(p->register_base + OCTEON_SPI_DAT0 + (8 * i), d);
131 mpi_tx.s.csid = spi->chip_select;
133 mpi_tx.s.leavecs = xfer->cs_change;
135 mpi_tx.s.leavecs = !xfer->cs_change;
136 mpi_tx.s.txnum = tx_buf ? len : 0;
137 mpi_tx.s.totnum = len;
138 cvmx_write_csr(p->register_base + OCTEON_SPI_TX, mpi_tx.u64);
140 octeon_spi_wait_ready(p);
142 for (i = 0; i < len; i++) {
143 u64 v = cvmx_read_csr(p->register_base + OCTEON_SPI_DAT0 + (8 * i));
147 if (xfer->delay_usecs)
148 udelay(xfer->delay_usecs);
153 static int octeon_spi_transfer_one_message(struct spi_master *master,
154 struct spi_message *msg)
156 struct octeon_spi *p = spi_master_get_devdata(master);
157 unsigned int total_len = 0;
159 struct spi_transfer *xfer;
161 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
162 bool last_xfer = list_is_last(&xfer->transfer_list,
164 int r = octeon_spi_do_transfer(p, msg, xfer, last_xfer);
172 msg->status = status;
173 msg->actual_length = total_len;
174 spi_finalize_current_message(master);
178 static int octeon_spi_probe(struct platform_device *pdev)
180 struct resource *res_mem;
181 struct spi_master *master;
182 struct octeon_spi *p;
185 master = spi_alloc_master(&pdev->dev, sizeof(struct octeon_spi));
188 p = spi_master_get_devdata(master);
189 platform_set_drvdata(pdev, master);
191 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
193 if (res_mem == NULL) {
194 dev_err(&pdev->dev, "found no memory resource\n");
198 if (!devm_request_mem_region(&pdev->dev, res_mem->start,
199 resource_size(res_mem), res_mem->name)) {
200 dev_err(&pdev->dev, "request_mem_region failed\n");
203 p->register_base = (u64)devm_ioremap(&pdev->dev, res_mem->start,
204 resource_size(res_mem));
206 /* Dynamic bus numbering */
207 master->bus_num = -1;
208 master->num_chipselect = 4;
209 master->mode_bits = SPI_CPHA |
215 master->transfer_one_message = octeon_spi_transfer_one_message;
216 master->bits_per_word_mask = SPI_BPW_MASK(8);
218 master->dev.of_node = pdev->dev.of_node;
219 err = devm_spi_register_master(&pdev->dev, master);
221 dev_err(&pdev->dev, "register master failed: %d\n", err);
225 dev_info(&pdev->dev, "OCTEON SPI bus driver\n");
229 spi_master_put(master);
233 static int octeon_spi_remove(struct platform_device *pdev)
235 struct spi_master *master = platform_get_drvdata(pdev);
236 struct octeon_spi *p = spi_master_get_devdata(master);
237 u64 register_base = p->register_base;
239 /* Clear the CSENA* and put everything in a known state. */
240 cvmx_write_csr(register_base + OCTEON_SPI_CFG, 0);
245 static struct of_device_id octeon_spi_match[] = {
246 { .compatible = "cavium,octeon-3010-spi", },
249 MODULE_DEVICE_TABLE(of, octeon_spi_match);
251 static struct platform_driver octeon_spi_driver = {
253 .name = "spi-octeon",
254 .owner = THIS_MODULE,
255 .of_match_table = octeon_spi_match,
257 .probe = octeon_spi_probe,
258 .remove = octeon_spi_remove,
261 module_platform_driver(octeon_spi_driver);
263 MODULE_DESCRIPTION("Cavium, Inc. OCTEON SPI bus driver");
264 MODULE_AUTHOR("David Daney");
265 MODULE_LICENSE("GPL");