--- /dev/null
+/*
+ * Driver of Andes SPI Controller
+ *
+ * (C) Copyright 2011 Andes Technology
+ * Macpaul Lin <macpaul@andestech.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+
+#include <asm/io.h>
+#include "andes_spi.h"
+
+void spi_init(void)
+{
+ /* do nothing */
+}
+
+static void andes_spi_spit_en(struct andes_spi_slave *ds)
+{
+ unsigned int dcr = readl(&ds->regs->dcr);
+
+ debug("%s: dcr: %x, write value: %x\n",
+ __func__, dcr, (dcr | ANDES_SPI_DCR_SPIT));
+
+ writel((dcr | ANDES_SPI_DCR_SPIT), &ds->regs->dcr);
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct andes_spi_slave *ds;
+
+ if (!spi_cs_is_valid(bus, cs))
+ return NULL;
+
+ ds = spi_alloc_slave(struct andes_spi_slave, bus, cs);
+ if (!ds)
+ return NULL;
+
+ ds->regs = (struct andes_spi_regs *)CONFIG_SYS_SPI_BASE;
+
+ /*
+ * The hardware of andes_spi will set its frequency according
+ * to APB/AHB bus clock. Hence the hardware doesn't allow changing of
+ * requency and so the user requested speed is always ignored.
+ */
+ ds->freq = max_hz;
+
+ return &ds->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ struct andes_spi_slave *ds = to_andes_spi(slave);
+
+ free(ds);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ struct andes_spi_slave *ds = to_andes_spi(slave);
+ unsigned int apb;
+ unsigned int baud;
+
+ /* Enable the SPI hardware */
+ writel(ANDES_SPI_CR_SPIRST, &ds->regs->cr);
+ udelay(1000);
+
+ /* setup format */
+ baud = ((CONFIG_SYS_CLK_FREQ / CONFIG_SYS_SPI_CLK / 2) - 1) & 0xFF;
+
+ /*
+ * SPI_CLK = AHB bus clock / ((BAUD + 1)*2)
+ * BAUD = AHB bus clock / SPI_CLK / 2) - 1
+ */
+ apb = (readl(&ds->regs->apb) & 0xffffff00) | baud;
+ writel(apb, &ds->regs->apb);
+
+ /* no interrupts */
+ writel(0, &ds->regs->ie);
+
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+ struct andes_spi_slave *ds = to_andes_spi(slave);
+
+ /* Disable the SPI hardware */
+ writel(ANDES_SPI_CR_SPIRST, &ds->regs->cr);
+}
+
+static int andes_spi_read(struct spi_slave *slave, unsigned int len,
+ u8 *rxp, unsigned long flags)
+{
+ struct andes_spi_slave *ds = to_andes_spi(slave);
+ unsigned int i, left;
+ unsigned int data;
+
+ debug("%s: slave: %x, len: %d, rxp: %x, flags: %d\n",
+ __func__, slave, len, rxp, flags);
+
+ debug("%s: data: ", __func__);
+ while (len > 0) {
+ left = min(len, 4);
+ data = readl(&ds->regs->data);
+
+ debug(" ");
+ for (i = 0; i < left; i++) {
+ debug("%02x ", data & 0xff);
+ *rxp++ = data;
+ data >>= 8;
+ len--;
+ }
+ }
+ debug("\n");
+
+ return 0;
+}
+
+static int andes_spi_write(struct spi_slave *slave, unsigned int wlen,
+ unsigned int rlen, const u8 *txp, unsigned long flags)
+{
+ struct andes_spi_slave *ds = to_andes_spi(slave);
+ unsigned int data;
+ unsigned int i, left;
+ unsigned int spit_enabled = 0;
+
+ debug("%s: slave: %x, wlen: %d, rlen: %d, txp: %x, flags: %x\n",
+ __func__, slave, wlen, rlen, txp, flags);
+
+ /* The value of wlen and rlen wrote to register must minus 1 */
+ if (rlen == 0) /* write only */
+ writel(ANDES_SPI_DCR_MODE_WO | ANDES_SPI_DCR_WCNT(wlen-1) |
+ ANDES_SPI_DCR_RCNT(0), &ds->regs->dcr);
+ else /* write then read */
+ writel(ANDES_SPI_DCR_MODE_WR | ANDES_SPI_DCR_WCNT(wlen-1) |
+ ANDES_SPI_DCR_RCNT(rlen-1), &ds->regs->dcr);
+
+ /* wait till SPIBSY is cleared */
+ while (readl(&ds->regs->st) & ANDES_SPI_ST_SPIBSY)
+ ;
+
+ /* data write process */
+ debug("%s: txp: ", __func__);
+ while (wlen > 0) {
+ /* clear the data */
+ data = 0;
+
+ /* data are usually be read 32bits once a time */
+ left = min(wlen, 4);
+
+ for (i = 0; i < left; i++) {
+ debug("%x ", *txp);
+ data |= *txp++ << (i * 8);
+ wlen--;
+ }
+ debug("\n");
+
+ debug("data: %08x\n", data);
+ debug("streg before write: %08x\n", readl(&ds->regs->st));
+ /* wait till TXFULL is deasserted */
+ while (readl(&ds->regs->st) & ANDES_SPI_ST_TXFEL)
+ ;
+ writel(data, &ds->regs->data);
+ debug("streg after write: %08x\n", readl(&ds->regs->st));
+
+
+ if (spit_enabled == 0) {
+ /* enable SPIT bit - trigger the tx and rx progress */
+ andes_spi_spit_en(ds);
+ spit_enabled = 1;
+ }
+
+ }
+ debug("\n");
+
+ return 0;
+}
+
+/*
+ * spi_xfer:
+ * Since andes_spi doesn't support independent command transaction,
+ * that is, write and than read must be operated in continuous
+ * execution, there is no need to set dcr and trigger spit again in
+ * RX process.
+ */
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ unsigned int len;
+ static int op_nextime;
+ static u8 tmp_cmd[5];
+ static int tmp_wlen;
+ unsigned int i;
+
+ if (bitlen == 0)
+ /* Finish any previously submitted transfers */
+ goto out;
+
+ if (bitlen % 8) {
+ /* Errors always terminate an ongoing transfer */
+ flags |= SPI_XFER_END;
+ goto out;
+ }
+
+ len = bitlen / 8;
+
+ debug("%s: slave: %08x, bitlen: %d, dout: "
+ "%08x, din: %08x, flags: %d, len: %d\n",
+ __func__, slave, bitlen, dout, din, flags, len);
+
+ /*
+ * Important:
+ * andes_spi's hardware doesn't support 2 data channel. The read
+ * and write cmd/data share the same register (data register).
+ *
+ * If a command has write and read transaction, you cannot do write
+ * this time and then do read on next time.
+ *
+ * A command writes first with a read response must indicating
+ * the read length in write operation. Hence the write action must
+ * be stored temporary and wait until the next read action has been
+ * arrived. Then we flush the write and read action out together.
+ */
+ if (!dout) {
+ if (op_nextime == 1) {
+ /* flags should be SPI_XFER_END, value is 2 */
+ op_nextime = 0;
+ andes_spi_write(slave, tmp_wlen, len, tmp_cmd, flags);
+ }
+ return andes_spi_read(slave, len, din, flags);
+ } else if (!din) {
+ if (flags == SPI_XFER_BEGIN) {
+ /* store the write command and do operation next time */
+ op_nextime = 1;
+ memset(tmp_cmd, 0, sizeof(tmp_cmd));
+ memcpy(tmp_cmd, dout, len);
+
+ debug("%s: tmp_cmd: ", __func__);
+ for (i = 0; i < len; i++)
+ debug("%x ", *(tmp_cmd + i));
+ debug("\n");
+
+ tmp_wlen = len;
+ } else {
+ /*
+ * flags should be (SPI_XFER_BEGIN | SPI_XFER_END),
+ * the value is 3.
+ */
+ if (op_nextime == 1) {
+ /* flags should be SPI_XFER_END, value is 2 */
+ op_nextime = 0;
+ /* flags 3 implies write only */
+ andes_spi_write(slave, tmp_wlen, 0, tmp_cmd, 3);
+ }
+
+ debug("flags: %x\n", flags);
+ return andes_spi_write(slave, len, 0, dout, flags);
+ }
+ }
+
+out:
+ return 0;
+}
+
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+ return bus == 0 && cs == 0;
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+ /* do nothing */
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+ /* do nothing */
+}
Code Review / kvmfornfv.git / blobdiff