--- /dev/null
+/*
+ * Copyright (c) 2006 Ben Warren, Qstreams Networks Inc.
+ * With help from the common/soft_spi and arch/powerpc/cpu/mpc8260 drivers
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+
+#include <malloc.h>
+#include <spi.h>
+#include <asm/mpc8xxx_spi.h>
+
+#define SPI_EV_NE (0x80000000 >> 22) /* Receiver Not Empty */
+#define SPI_EV_NF (0x80000000 >> 23) /* Transmitter Not Full */
+
+#define SPI_MODE_LOOP (0x80000000 >> 1) /* Loopback mode */
+#define SPI_MODE_REV (0x80000000 >> 5) /* Reverse mode - MSB first */
+#define SPI_MODE_MS (0x80000000 >> 6) /* Always master */
+#define SPI_MODE_EN (0x80000000 >> 7) /* Enable interface */
+
+#define SPI_TIMEOUT 1000
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct spi_slave *slave;
+
+ if (!spi_cs_is_valid(bus, cs))
+ return NULL;
+
+ slave = spi_alloc_slave_base(bus, cs);
+ if (!slave)
+ return NULL;
+
+ /*
+ * TODO: Some of the code in spi_init() should probably move
+ * here, or into spi_claim_bus() below.
+ */
+
+ return slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ free(slave);
+}
+
+void spi_init(void)
+{
+ volatile spi8xxx_t *spi = &((immap_t *) (CONFIG_SYS_IMMR))->spi;
+
+ /*
+ * SPI pins on the MPC83xx are not muxed, so all we do is initialize
+ * some registers
+ */
+ spi->mode = SPI_MODE_REV | SPI_MODE_MS | SPI_MODE_EN;
+ spi->mode = (spi->mode & 0xfff0ffff) | (1 << 16); /* Use SYSCLK / 8
+ (16.67MHz typ.) */
+ spi->event = 0xffffffff; /* Clear all SPI events */
+ spi->mask = 0x00000000; /* Mask all SPI interrupts */
+ spi->com = 0; /* LST bit doesn't do anything, so disregard */
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+ void *din, unsigned long flags)
+{
+ volatile spi8xxx_t *spi = &((immap_t *) (CONFIG_SYS_IMMR))->spi;
+ unsigned int tmpdout, tmpdin, event;
+ int numBlks = DIV_ROUND_UP(bitlen, 32);
+ int tm, isRead = 0;
+ unsigned char charSize = 32;
+
+ debug("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
+ slave->bus, slave->cs, *(uint *) dout, *(uint *) din, bitlen);
+
+ if (flags & SPI_XFER_BEGIN)
+ spi_cs_activate(slave);
+
+ spi->event = 0xffffffff; /* Clear all SPI events */
+
+ /* handle data in 32-bit chunks */
+ while (numBlks--) {
+ tmpdout = 0;
+ charSize = (bitlen >= 32 ? 32 : bitlen);
+
+ /* Shift data so it's msb-justified */
+ tmpdout = *(u32 *) dout >> (32 - charSize);
+
+ /* The LEN field of the SPMODE register is set as follows:
+ *
+ * Bit length setting
+ * len <= 4 3
+ * 4 < len <= 16 len - 1
+ * len > 16 0
+ */
+
+ spi->mode &= ~SPI_MODE_EN;
+
+ if (bitlen <= 16) {
+ if (bitlen <= 4)
+ spi->mode = (spi->mode & 0xff0fffff) |
+ (3 << 20);
+ else
+ spi->mode = (spi->mode & 0xff0fffff) |
+ ((bitlen - 1) << 20);
+ } else {
+ spi->mode = (spi->mode & 0xff0fffff);
+ /* Set up the next iteration if sending > 32 bits */
+ bitlen -= 32;
+ dout += 4;
+ }
+
+ spi->mode |= SPI_MODE_EN;
+
+ spi->tx = tmpdout; /* Write the data out */
+ debug("*** spi_xfer: ... %08x written\n", tmpdout);
+
+ /*
+ * Wait for SPI transmit to get out
+ * or time out (1 second = 1000 ms)
+ * The NE event must be read and cleared first
+ */
+ for (tm = 0, isRead = 0; tm < SPI_TIMEOUT; ++tm) {
+ event = spi->event;
+ if (event & SPI_EV_NE) {
+ tmpdin = spi->rx;
+ spi->event |= SPI_EV_NE;
+ isRead = 1;
+
+ *(u32 *) din = (tmpdin << (32 - charSize));
+ if (charSize == 32) {
+ /* Advance output buffer by 32 bits */
+ din += 4;
+ }
+ }
+ /*
+ * Only bail when we've had both NE and NF events.
+ * This will cause timeouts on RO devices, so maybe
+ * in the future put an arbitrary delay after writing
+ * the device. Arbitrary delays suck, though...
+ */
+ if (isRead && (event & SPI_EV_NF))
+ break;
+ }
+ if (tm >= SPI_TIMEOUT)
+ puts("*** spi_xfer: Time out during SPI transfer");
+
+ debug("*** spi_xfer: transfer ended. Value=%08x\n", tmpdin);
+ }
+
+ if (flags & SPI_XFER_END)
+ spi_cs_deactivate(slave);
+
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff