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>
17 #include <asm/octeon/octeon.h>
18 #include <asm/octeon/cvmx-mpi-defs.h>
20 #define OCTEON_SPI_MAX_BYTES 9
22 #define OCTEON_SPI_MAX_CLOCK_HZ 16000000
24 struct octeon_spi_regs {
32 void __iomem *register_base;
36 struct octeon_spi_regs regs;
39 #define OCTEON_SPI_CFG(x) (x->regs.config)
40 #define OCTEON_SPI_STS(x) (x->regs.status)
41 #define OCTEON_SPI_TX(x) (x->regs.tx)
42 #define OCTEON_SPI_DAT0(x) (x->regs.data)
44 static void octeon_spi_wait_ready(struct octeon_spi *p)
46 union cvmx_mpi_sts mpi_sts;
47 unsigned int loops = 0;
52 mpi_sts.u64 = readq(p->register_base + OCTEON_SPI_STS(p));
53 } while (mpi_sts.s.busy);
56 static int octeon_spi_do_transfer(struct octeon_spi *p,
57 struct spi_message *msg,
58 struct spi_transfer *xfer,
61 struct spi_device *spi = msg->spi;
62 union cvmx_mpi_cfg mpi_cfg;
63 union cvmx_mpi_tx mpi_tx;
73 cpha = mode & SPI_CPHA;
74 cpol = mode & SPI_CPOL;
76 clkdiv = p->sys_freq / (2 * xfer->speed_hz);
80 mpi_cfg.s.clkdiv = clkdiv;
81 mpi_cfg.s.cshi = (mode & SPI_CS_HIGH) ? 1 : 0;
82 mpi_cfg.s.lsbfirst = (mode & SPI_LSB_FIRST) ? 1 : 0;
83 mpi_cfg.s.wireor = (mode & SPI_3WIRE) ? 1 : 0;
84 mpi_cfg.s.idlelo = cpha != cpol;
85 mpi_cfg.s.cslate = cpha ? 1 : 0;
88 if (spi->chip_select < 4)
89 p->cs_enax |= 1ull << (12 + spi->chip_select);
90 mpi_cfg.u64 |= p->cs_enax;
92 if (mpi_cfg.u64 != p->last_cfg) {
93 p->last_cfg = mpi_cfg.u64;
94 writeq(mpi_cfg.u64, p->register_base + OCTEON_SPI_CFG(p));
96 tx_buf = xfer->tx_buf;
97 rx_buf = xfer->rx_buf;
99 while (len > OCTEON_SPI_MAX_BYTES) {
100 for (i = 0; i < OCTEON_SPI_MAX_BYTES; i++) {
106 writeq(d, p->register_base + OCTEON_SPI_DAT0(p) + (8 * i));
109 mpi_tx.s.csid = spi->chip_select;
110 mpi_tx.s.leavecs = 1;
111 mpi_tx.s.txnum = tx_buf ? OCTEON_SPI_MAX_BYTES : 0;
112 mpi_tx.s.totnum = OCTEON_SPI_MAX_BYTES;
113 writeq(mpi_tx.u64, p->register_base + OCTEON_SPI_TX(p));
115 octeon_spi_wait_ready(p);
117 for (i = 0; i < OCTEON_SPI_MAX_BYTES; i++) {
118 u64 v = readq(p->register_base + OCTEON_SPI_DAT0(p) + (8 * i));
121 len -= OCTEON_SPI_MAX_BYTES;
124 for (i = 0; i < len; i++) {
130 writeq(d, p->register_base + OCTEON_SPI_DAT0(p) + (8 * i));
134 mpi_tx.s.csid = spi->chip_select;
136 mpi_tx.s.leavecs = xfer->cs_change;
138 mpi_tx.s.leavecs = !xfer->cs_change;
139 mpi_tx.s.txnum = tx_buf ? len : 0;
140 mpi_tx.s.totnum = len;
141 writeq(mpi_tx.u64, p->register_base + OCTEON_SPI_TX(p));
143 octeon_spi_wait_ready(p);
145 for (i = 0; i < len; i++) {
146 u64 v = readq(p->register_base + OCTEON_SPI_DAT0(p) + (8 * i));
150 if (xfer->delay_usecs)
151 udelay(xfer->delay_usecs);
156 static int octeon_spi_transfer_one_message(struct spi_master *master,
157 struct spi_message *msg)
159 struct octeon_spi *p = spi_master_get_devdata(master);
160 unsigned int total_len = 0;
162 struct spi_transfer *xfer;
164 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
165 bool last_xfer = list_is_last(&xfer->transfer_list,
167 int r = octeon_spi_do_transfer(p, msg, xfer, last_xfer);
175 msg->status = status;
176 msg->actual_length = total_len;
177 spi_finalize_current_message(master);
181 static int octeon_spi_probe(struct platform_device *pdev)
183 struct resource *res_mem;
184 void __iomem *reg_base;
185 struct spi_master *master;
186 struct octeon_spi *p;
189 master = spi_alloc_master(&pdev->dev, sizeof(struct octeon_spi));
192 p = spi_master_get_devdata(master);
193 platform_set_drvdata(pdev, master);
195 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
196 reg_base = devm_ioremap_resource(&pdev->dev, res_mem);
197 if (IS_ERR(reg_base)) {
198 err = PTR_ERR(reg_base);
202 p->register_base = reg_base;
203 p->sys_freq = octeon_get_io_clock_rate();
206 p->regs.status = 0x08;
210 master->num_chipselect = 4;
211 master->mode_bits = SPI_CPHA |
217 master->transfer_one_message = octeon_spi_transfer_one_message;
218 master->bits_per_word_mask = SPI_BPW_MASK(8);
219 master->max_speed_hz = OCTEON_SPI_MAX_CLOCK_HZ;
221 master->dev.of_node = pdev->dev.of_node;
222 err = devm_spi_register_master(&pdev->dev, master);
224 dev_err(&pdev->dev, "register master failed: %d\n", err);
228 dev_info(&pdev->dev, "OCTEON SPI bus driver\n");
232 spi_master_put(master);
236 static int octeon_spi_remove(struct platform_device *pdev)
238 struct spi_master *master = platform_get_drvdata(pdev);
239 struct octeon_spi *p = spi_master_get_devdata(master);
241 /* Clear the CSENA* and put everything in a known state. */
242 writeq(0, p->register_base + OCTEON_SPI_CFG(p));
247 static const struct of_device_id octeon_spi_match[] = {
248 { .compatible = "cavium,octeon-3010-spi", },
251 MODULE_DEVICE_TABLE(of, octeon_spi_match);
253 static struct platform_driver octeon_spi_driver = {
255 .name = "spi-octeon",
256 .of_match_table = octeon_spi_match,
258 .probe = octeon_spi_probe,
259 .remove = octeon_spi_remove,
262 module_platform_driver(octeon_spi_driver);
264 MODULE_DESCRIPTION("Cavium, Inc. OCTEON SPI bus driver");
265 MODULE_AUTHOR("David Daney");
266 MODULE_LICENSE("GPL");