--- /dev/null
+/*
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+#include <common.h>
+#include <spi.h>
+#include <malloc.h>
+
+#include <asm/io.h>
+
+#include <asm/arch/clk.h>
+#include <asm/arch/hardware.h>
+
+#include "atmel_spi.h"
+
+static int spi_has_wdrbt(struct atmel_spi_slave *slave)
+{
+ unsigned int ver;
+
+ ver = spi_readl(slave, VERSION);
+
+ return (ATMEL_SPI_VERSION_REV(ver) >= 0x210);
+}
+
+void spi_init()
+{
+
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct atmel_spi_slave *as;
+ unsigned int scbr;
+ u32 csrx;
+ void *regs;
+
+ if (!spi_cs_is_valid(bus, cs))
+ return NULL;
+
+ switch (bus) {
+ case 0:
+ regs = (void *)ATMEL_BASE_SPI0;
+ break;
+#ifdef ATMEL_BASE_SPI1
+ case 1:
+ regs = (void *)ATMEL_BASE_SPI1;
+ break;
+#endif
+#ifdef ATMEL_BASE_SPI2
+ case 2:
+ regs = (void *)ATMEL_BASE_SPI2;
+ break;
+#endif
+#ifdef ATMEL_BASE_SPI3
+ case 3:
+ regs = (void *)ATMEL_BASE_SPI3;
+ break;
+#endif
+ default:
+ return NULL;
+ }
+
+
+ scbr = (get_spi_clk_rate(bus) + max_hz - 1) / max_hz;
+ if (scbr > ATMEL_SPI_CSRx_SCBR_MAX)
+ /* Too low max SCK rate */
+ return NULL;
+ if (scbr < 1)
+ scbr = 1;
+
+ csrx = ATMEL_SPI_CSRx_SCBR(scbr);
+ csrx |= ATMEL_SPI_CSRx_BITS(ATMEL_SPI_BITS_8);
+ if (!(mode & SPI_CPHA))
+ csrx |= ATMEL_SPI_CSRx_NCPHA;
+ if (mode & SPI_CPOL)
+ csrx |= ATMEL_SPI_CSRx_CPOL;
+
+ as = spi_alloc_slave(struct atmel_spi_slave, bus, cs);
+ if (!as)
+ return NULL;
+
+ as->regs = regs;
+ as->mr = ATMEL_SPI_MR_MSTR | ATMEL_SPI_MR_MODFDIS
+ | ATMEL_SPI_MR_PCS(~(1 << cs) & 0xf);
+ if (spi_has_wdrbt(as))
+ as->mr |= ATMEL_SPI_MR_WDRBT;
+
+ spi_writel(as, CSR(cs), csrx);
+
+ return &as->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ struct atmel_spi_slave *as = to_atmel_spi(slave);
+
+ free(as);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ struct atmel_spi_slave *as = to_atmel_spi(slave);
+
+ /* Enable the SPI hardware */
+ spi_writel(as, CR, ATMEL_SPI_CR_SPIEN);
+
+ /*
+ * Select the slave. This should set SCK to the correct
+ * initial state, etc.
+ */
+ spi_writel(as, MR, as->mr);
+
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+ struct atmel_spi_slave *as = to_atmel_spi(slave);
+
+ /* Disable the SPI hardware */
+ spi_writel(as, CR, ATMEL_SPI_CR_SPIDIS);
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ struct atmel_spi_slave *as = to_atmel_spi(slave);
+ unsigned int len_tx;
+ unsigned int len_rx;
+ unsigned int len;
+ u32 status;
+ const u8 *txp = dout;
+ u8 *rxp = din;
+ u8 value;
+
+ if (bitlen == 0)
+ /* Finish any previously submitted transfers */
+ goto out;
+
+ /*
+ * TODO: The controller can do non-multiple-of-8 bit
+ * transfers, but this driver currently doesn't support it.
+ *
+ * It's also not clear how such transfers are supposed to be
+ * represented as a stream of bytes...this is a limitation of
+ * the current SPI interface.
+ */
+ if (bitlen % 8) {
+ /* Errors always terminate an ongoing transfer */
+ flags |= SPI_XFER_END;
+ goto out;
+ }
+
+ len = bitlen / 8;
+
+ /*
+ * The controller can do automatic CS control, but it is
+ * somewhat quirky, and it doesn't really buy us much anyway
+ * in the context of U-Boot.
+ */
+ if (flags & SPI_XFER_BEGIN) {
+ spi_cs_activate(slave);
+ /*
+ * sometimes the RDR is not empty when we get here,
+ * in theory that should not happen, but it DOES happen.
+ * Read it here to be on the safe side.
+ * That also clears the OVRES flag. Required if the
+ * following loop exits due to OVRES!
+ */
+ spi_readl(as, RDR);
+ }
+
+ for (len_tx = 0, len_rx = 0; len_rx < len; ) {
+ status = spi_readl(as, SR);
+
+ if (status & ATMEL_SPI_SR_OVRES)
+ return -1;
+
+ if (len_tx < len && (status & ATMEL_SPI_SR_TDRE)) {
+ if (txp)
+ value = *txp++;
+ else
+ value = 0;
+ spi_writel(as, TDR, value);
+ len_tx++;
+ }
+ if (status & ATMEL_SPI_SR_RDRF) {
+ value = spi_readl(as, RDR);
+ if (rxp)
+ *rxp++ = value;
+ len_rx++;
+ }
+ }
+
+out:
+ if (flags & SPI_XFER_END) {
+ /*
+ * Wait until the transfer is completely done before
+ * we deactivate CS.
+ */
+ do {
+ status = spi_readl(as, SR);
+ } while (!(status & ATMEL_SPI_SR_TXEMPTY));
+
+ spi_cs_deactivate(slave);
+ }
+
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff