--- /dev/null
+/*
+ * Xilinx SPI driver
+ *
+ * supports 8 bit SPI transfers only, with or w/o FIFO
+ *
+ * based on bfin_spi.c, by way of altera_spi.c
+ * Copyright (c) 2005-2008 Analog Devices Inc.
+ * Copyright (c) 2010 Thomas Chou <thomas@wytron.com.tw>
+ * Copyright (c) 2010 Graeme Smecher <graeme.smecher@mail.mcgill.ca>
+ * Copyright (c) 2012 Stephan Linz <linz@li-pro.net>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * [0]: http://www.xilinx.com/support/documentation
+ *
+ * [S]: [0]/ip_documentation/xps_spi.pdf
+ * [0]/ip_documentation/axi_spi_ds742.pdf
+ */
+#include <config.h>
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+
+#include "xilinx_spi.h"
+
+#ifndef CONFIG_SYS_XILINX_SPI_LIST
+#define CONFIG_SYS_XILINX_SPI_LIST { CONFIG_SYS_SPI_BASE }
+#endif
+
+#ifndef CONFIG_XILINX_SPI_IDLE_VAL
+#define CONFIG_XILINX_SPI_IDLE_VAL 0xff
+#endif
+
+#define XILSPI_SPICR_DFLT_ON (SPICR_MANUAL_SS | \
+ SPICR_MASTER_MODE | \
+ SPICR_SPE)
+
+#define XILSPI_SPICR_DFLT_OFF (SPICR_MASTER_INHIBIT | \
+ SPICR_MANUAL_SS)
+
+#define XILSPI_MAX_XFER_BITS 8
+
+static unsigned long xilinx_spi_base_list[] = CONFIG_SYS_XILINX_SPI_LIST;
+
+__attribute__((weak))
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+ return bus < ARRAY_SIZE(xilinx_spi_base_list) && cs < 32;
+}
+
+__attribute__((weak))
+void spi_cs_activate(struct spi_slave *slave)
+{
+ struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
+
+ writel(SPISSR_ACT(slave->cs), &xilspi->regs->spissr);
+}
+
+__attribute__((weak))
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+ struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
+
+ writel(SPISSR_OFF, &xilspi->regs->spissr);
+}
+
+void spi_init(void)
+{
+ /* do nothing */
+}
+
+void spi_set_speed(struct spi_slave *slave, uint hz)
+{
+ /* xilinx spi core does not support programmable speed */
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct xilinx_spi_slave *xilspi;
+
+ if (!spi_cs_is_valid(bus, cs)) {
+ printf("XILSPI error: %s: unsupported bus %d / cs %d\n",
+ __func__, bus, cs);
+ return NULL;
+ }
+
+ xilspi = spi_alloc_slave(struct xilinx_spi_slave, bus, cs);
+ if (!xilspi) {
+ printf("XILSPI error: %s: malloc of SPI structure failed\n",
+ __func__);
+ return NULL;
+ }
+ xilspi->regs = (struct xilinx_spi_reg *)xilinx_spi_base_list[bus];
+ xilspi->freq = max_hz;
+ xilspi->mode = mode;
+ debug("%s: bus:%i cs:%i base:%p mode:%x max_hz:%d\n", __func__,
+ bus, cs, xilspi->regs, xilspi->mode, xilspi->freq);
+
+ writel(SPISSR_RESET_VALUE, &xilspi->regs->srr);
+
+ return &xilspi->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
+
+ free(xilspi);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
+ u32 spicr;
+
+ debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
+ writel(SPISSR_OFF, &xilspi->regs->spissr);
+
+ spicr = XILSPI_SPICR_DFLT_ON;
+ if (xilspi->mode & SPI_LSB_FIRST)
+ spicr |= SPICR_LSB_FIRST;
+ if (xilspi->mode & SPI_CPHA)
+ spicr |= SPICR_CPHA;
+ if (xilspi->mode & SPI_CPOL)
+ spicr |= SPICR_CPOL;
+ if (xilspi->mode & SPI_LOOP)
+ spicr |= SPICR_LOOP;
+
+ writel(spicr, &xilspi->regs->spicr);
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+ struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
+
+ debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
+ writel(SPISSR_OFF, &xilspi->regs->spissr);
+ writel(XILSPI_SPICR_DFLT_OFF, &xilspi->regs->spicr);
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+ void *din, unsigned long flags)
+{
+ struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
+ /* assume spi core configured to do 8 bit transfers */
+ unsigned int bytes = bitlen / XILSPI_MAX_XFER_BITS;
+ const unsigned char *txp = dout;
+ unsigned char *rxp = din;
+ unsigned rxecount = 17; /* max. 16 elements in FIFO, leftover 1 */
+ unsigned global_timeout;
+
+ debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
+ slave->bus, slave->cs, bitlen, bytes, flags);
+ if (bitlen == 0)
+ goto done;
+
+ if (bitlen % XILSPI_MAX_XFER_BITS) {
+ printf("XILSPI warning: %s: Not a multiple of %d bits\n",
+ __func__, XILSPI_MAX_XFER_BITS);
+ flags |= SPI_XFER_END;
+ goto done;
+ }
+
+ /* empty read buffer */
+ while (rxecount && !(readl(&xilspi->regs->spisr) & SPISR_RX_EMPTY)) {
+ readl(&xilspi->regs->spidrr);
+ rxecount--;
+ }
+
+ if (!rxecount) {
+ printf("XILSPI error: %s: Rx buffer not empty\n", __func__);
+ return -1;
+ }
+
+ if (flags & SPI_XFER_BEGIN)
+ spi_cs_activate(slave);
+
+ /* at least 1usec or greater, leftover 1 */
+ global_timeout = xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
+ (XILSPI_MAX_XFER_BITS * 1000000 / xilspi->freq) + 1;
+
+ while (bytes--) {
+ unsigned timeout = global_timeout;
+ /* get Tx element from data out buffer and count up */
+ unsigned char d = txp ? *txp++ : CONFIG_XILINX_SPI_IDLE_VAL;
+ debug("%s: tx:%x ", __func__, d);
+
+ /* write out and wait for processing (receive data) */
+ writel(d & SPIDTR_8BIT_MASK, &xilspi->regs->spidtr);
+ while (timeout && readl(&xilspi->regs->spisr)
+ & SPISR_RX_EMPTY) {
+ timeout--;
+ udelay(1);
+ }
+
+ if (!timeout) {
+ printf("XILSPI error: %s: Xfer timeout\n", __func__);
+ return -1;
+ }
+
+ /* read Rx element and push into data in buffer */
+ d = readl(&xilspi->regs->spidrr) & SPIDRR_8BIT_MASK;
+ if (rxp)
+ *rxp++ = d;
+ debug("rx:%x\n", d);
+ }
+
+ done:
+ if (flags & SPI_XFER_END)
+ spi_cs_deactivate(slave);
+
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff