--- /dev/null
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2011, 2012 Cavium, Inc.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/spi/spi.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#include <asm/octeon/octeon.h>
+#include <asm/octeon/cvmx-mpi-defs.h>
+
+#define OCTEON_SPI_CFG 0
+#define OCTEON_SPI_STS 0x08
+#define OCTEON_SPI_TX 0x10
+#define OCTEON_SPI_DAT0 0x80
+
+#define OCTEON_SPI_MAX_BYTES 9
+
+#define OCTEON_SPI_MAX_CLOCK_HZ 16000000
+
+struct octeon_spi {
+ u64 register_base;
+ u64 last_cfg;
+ u64 cs_enax;
+};
+
+static void octeon_spi_wait_ready(struct octeon_spi *p)
+{
+ union cvmx_mpi_sts mpi_sts;
+ unsigned int loops = 0;
+
+ do {
+ if (loops++)
+ __delay(500);
+ mpi_sts.u64 = cvmx_read_csr(p->register_base + OCTEON_SPI_STS);
+ } while (mpi_sts.s.busy);
+}
+
+static int octeon_spi_do_transfer(struct octeon_spi *p,
+ struct spi_message *msg,
+ struct spi_transfer *xfer,
+ bool last_xfer)
+{
+ struct spi_device *spi = msg->spi;
+ union cvmx_mpi_cfg mpi_cfg;
+ union cvmx_mpi_tx mpi_tx;
+ unsigned int clkdiv;
+ unsigned int speed_hz;
+ int mode;
+ bool cpha, cpol;
+ const u8 *tx_buf;
+ u8 *rx_buf;
+ int len;
+ int i;
+
+ mode = spi->mode;
+ cpha = mode & SPI_CPHA;
+ cpol = mode & SPI_CPOL;
+
+ speed_hz = xfer->speed_hz ? : spi->max_speed_hz;
+
+ clkdiv = octeon_get_io_clock_rate() / (2 * speed_hz);
+
+ mpi_cfg.u64 = 0;
+
+ mpi_cfg.s.clkdiv = clkdiv;
+ mpi_cfg.s.cshi = (mode & SPI_CS_HIGH) ? 1 : 0;
+ mpi_cfg.s.lsbfirst = (mode & SPI_LSB_FIRST) ? 1 : 0;
+ mpi_cfg.s.wireor = (mode & SPI_3WIRE) ? 1 : 0;
+ mpi_cfg.s.idlelo = cpha != cpol;
+ mpi_cfg.s.cslate = cpha ? 1 : 0;
+ mpi_cfg.s.enable = 1;
+
+ if (spi->chip_select < 4)
+ p->cs_enax |= 1ull << (12 + spi->chip_select);
+ mpi_cfg.u64 |= p->cs_enax;
+
+ if (mpi_cfg.u64 != p->last_cfg) {
+ p->last_cfg = mpi_cfg.u64;
+ cvmx_write_csr(p->register_base + OCTEON_SPI_CFG, mpi_cfg.u64);
+ }
+ tx_buf = xfer->tx_buf;
+ rx_buf = xfer->rx_buf;
+ len = xfer->len;
+ while (len > OCTEON_SPI_MAX_BYTES) {
+ for (i = 0; i < OCTEON_SPI_MAX_BYTES; i++) {
+ u8 d;
+ if (tx_buf)
+ d = *tx_buf++;
+ else
+ d = 0;
+ cvmx_write_csr(p->register_base + OCTEON_SPI_DAT0 + (8 * i), d);
+ }
+ mpi_tx.u64 = 0;
+ mpi_tx.s.csid = spi->chip_select;
+ mpi_tx.s.leavecs = 1;
+ mpi_tx.s.txnum = tx_buf ? OCTEON_SPI_MAX_BYTES : 0;
+ mpi_tx.s.totnum = OCTEON_SPI_MAX_BYTES;
+ cvmx_write_csr(p->register_base + OCTEON_SPI_TX, mpi_tx.u64);
+
+ octeon_spi_wait_ready(p);
+ if (rx_buf)
+ for (i = 0; i < OCTEON_SPI_MAX_BYTES; i++) {
+ u64 v = cvmx_read_csr(p->register_base + OCTEON_SPI_DAT0 + (8 * i));
+ *rx_buf++ = (u8)v;
+ }
+ len -= OCTEON_SPI_MAX_BYTES;
+ }
+
+ for (i = 0; i < len; i++) {
+ u8 d;
+ if (tx_buf)
+ d = *tx_buf++;
+ else
+ d = 0;
+ cvmx_write_csr(p->register_base + OCTEON_SPI_DAT0 + (8 * i), d);
+ }
+
+ mpi_tx.u64 = 0;
+ mpi_tx.s.csid = spi->chip_select;
+ if (last_xfer)
+ mpi_tx.s.leavecs = xfer->cs_change;
+ else
+ mpi_tx.s.leavecs = !xfer->cs_change;
+ mpi_tx.s.txnum = tx_buf ? len : 0;
+ mpi_tx.s.totnum = len;
+ cvmx_write_csr(p->register_base + OCTEON_SPI_TX, mpi_tx.u64);
+
+ octeon_spi_wait_ready(p);
+ if (rx_buf)
+ for (i = 0; i < len; i++) {
+ u64 v = cvmx_read_csr(p->register_base + OCTEON_SPI_DAT0 + (8 * i));
+ *rx_buf++ = (u8)v;
+ }
+
+ if (xfer->delay_usecs)
+ udelay(xfer->delay_usecs);
+
+ return xfer->len;
+}
+
+static int octeon_spi_transfer_one_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct octeon_spi *p = spi_master_get_devdata(master);
+ unsigned int total_len = 0;
+ int status = 0;
+ struct spi_transfer *xfer;
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ bool last_xfer = list_is_last(&xfer->transfer_list,
+ &msg->transfers);
+ int r = octeon_spi_do_transfer(p, msg, xfer, last_xfer);
+ if (r < 0) {
+ status = r;
+ goto err;
+ }
+ total_len += r;
+ }
+err:
+ msg->status = status;
+ msg->actual_length = total_len;
+ spi_finalize_current_message(master);
+ return status;
+}
+
+static int octeon_spi_probe(struct platform_device *pdev)
+{
+ struct resource *res_mem;
+ struct spi_master *master;
+ struct octeon_spi *p;
+ int err = -ENOENT;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(struct octeon_spi));
+ if (!master)
+ return -ENOMEM;
+ p = spi_master_get_devdata(master);
+ platform_set_drvdata(pdev, master);
+
+ res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ if (res_mem == NULL) {
+ dev_err(&pdev->dev, "found no memory resource\n");
+ err = -ENXIO;
+ goto fail;
+ }
+ if (!devm_request_mem_region(&pdev->dev, res_mem->start,
+ resource_size(res_mem), res_mem->name)) {
+ dev_err(&pdev->dev, "request_mem_region failed\n");
+ goto fail;
+ }
+ p->register_base = (u64)devm_ioremap(&pdev->dev, res_mem->start,
+ resource_size(res_mem));
+
+ master->num_chipselect = 4;
+ master->mode_bits = SPI_CPHA |
+ SPI_CPOL |
+ SPI_CS_HIGH |
+ SPI_LSB_FIRST |
+ SPI_3WIRE;
+
+ master->transfer_one_message = octeon_spi_transfer_one_message;
+ master->bits_per_word_mask = SPI_BPW_MASK(8);
+ master->max_speed_hz = OCTEON_SPI_MAX_CLOCK_HZ;
+
+ master->dev.of_node = pdev->dev.of_node;
+ err = devm_spi_register_master(&pdev->dev, master);
+ if (err) {
+ dev_err(&pdev->dev, "register master failed: %d\n", err);
+ goto fail;
+ }
+
+ dev_info(&pdev->dev, "OCTEON SPI bus driver\n");
+
+ return 0;
+fail:
+ spi_master_put(master);
+ return err;
+}
+
+static int octeon_spi_remove(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct octeon_spi *p = spi_master_get_devdata(master);
+ u64 register_base = p->register_base;
+
+ /* Clear the CSENA* and put everything in a known state. */
+ cvmx_write_csr(register_base + OCTEON_SPI_CFG, 0);
+
+ return 0;
+}
+
+static const struct of_device_id octeon_spi_match[] = {
+ { .compatible = "cavium,octeon-3010-spi", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, octeon_spi_match);
+
+static struct platform_driver octeon_spi_driver = {
+ .driver = {
+ .name = "spi-octeon",
+ .of_match_table = octeon_spi_match,
+ },
+ .probe = octeon_spi_probe,
+ .remove = octeon_spi_remove,
+};
+
+module_platform_driver(octeon_spi_driver);
+
+MODULE_DESCRIPTION("Cavium, Inc. OCTEON SPI bus driver");
+MODULE_AUTHOR("David Daney");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff