--- /dev/null
+/*
+ * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * Driver for SPI controller on DaVinci. Based on atmel_spi.c
+ * by Atmel Corporation
+ *
+ * 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/hardware.h>
+#include "davinci_spi.h"
+
+void spi_init()
+{
+ /* do nothing */
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct davinci_spi_slave *ds;
+
+ if (!spi_cs_is_valid(bus, cs))
+ return NULL;
+
+ ds = spi_alloc_slave(struct davinci_spi_slave, bus, cs);
+ if (!ds)
+ return NULL;
+
+ ds->slave.bus = bus;
+ ds->slave.cs = cs;
+
+ switch (bus) {
+ case SPI0_BUS:
+ ds->regs = (struct davinci_spi_regs *)SPI0_BASE;
+ break;
+#ifdef CONFIG_SYS_SPI1
+ case SPI1_BUS:
+ ds->regs = (struct davinci_spi_regs *)SPI0_BASE;
+ break;
+#endif
+#ifdef CONFIG_SYS_SPI2
+ case SPI2_BUS:
+ ds->regs = (struct davinci_spi_regs *)SPI2_BASE;
+ break;
+#endif
+ default: /* Invalid bus number */
+ return NULL;
+ }
+
+ ds->freq = max_hz;
+
+ return &ds->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ struct davinci_spi_slave *ds = to_davinci_spi(slave);
+
+ free(ds);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ struct davinci_spi_slave *ds = to_davinci_spi(slave);
+ unsigned int scalar;
+
+ /* Enable the SPI hardware */
+ writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
+ udelay(1000);
+ writel(SPIGCR0_SPIENA_MASK, &ds->regs->gcr0);
+
+ /* Set master mode, powered up and not activated */
+ writel(SPIGCR1_MASTER_MASK | SPIGCR1_CLKMOD_MASK, &ds->regs->gcr1);
+
+ /* CS, CLK, SIMO and SOMI are functional pins */
+ writel(((1 << slave->cs) | SPIPC0_CLKFUN_MASK |
+ SPIPC0_DOFUN_MASK | SPIPC0_DIFUN_MASK), &ds->regs->pc0);
+
+ /* setup format */
+ scalar = ((CONFIG_SYS_SPI_CLK / ds->freq) - 1) & 0xFF;
+
+ /*
+ * Use following format:
+ * character length = 8,
+ * clock signal delayed by half clk cycle,
+ * clock low in idle state - Mode 0,
+ * MSB shifted out first
+ */
+ writel(8 | (scalar << SPIFMT_PRESCALE_SHIFT) |
+ (1 << SPIFMT_PHASE_SHIFT), &ds->regs->fmt0);
+
+ /*
+ * Including a minor delay. No science here. Should be good even with
+ * no delay
+ */
+ writel((50 << SPI_C2TDELAY_SHIFT) |
+ (50 << SPI_T2CDELAY_SHIFT), &ds->regs->delay);
+
+ /* default chip select register */
+ writel(SPIDEF_CSDEF0_MASK, &ds->regs->def);
+
+ /* no interrupts */
+ writel(0, &ds->regs->int0);
+ writel(0, &ds->regs->lvl);
+
+ /* enable SPI */
+ writel((readl(&ds->regs->gcr1) | SPIGCR1_SPIENA_MASK), &ds->regs->gcr1);
+
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+ struct davinci_spi_slave *ds = to_davinci_spi(slave);
+
+ /* Disable the SPI hardware */
+ writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
+}
+
+/*
+ * This functions needs to act like a macro to avoid pipeline reloads in the
+ * loops below. Use always_inline. This gains us about 160KiB/s and the bloat
+ * appears to be zero bytes (da830).
+ */
+__attribute__((always_inline))
+static inline u32 davinci_spi_xfer_data(struct davinci_spi_slave *ds, u32 data)
+{
+ u32 buf_reg_val;
+
+ /* send out data */
+ writel(data, &ds->regs->dat1);
+
+ /* wait for the data to clock in/out */
+ while ((buf_reg_val = readl(&ds->regs->buf)) & SPIBUF_RXEMPTY_MASK)
+ ;
+
+ return buf_reg_val;
+}
+
+static int davinci_spi_read(struct spi_slave *slave, unsigned int len,
+ u8 *rxp, unsigned long flags)
+{
+ struct davinci_spi_slave *ds = to_davinci_spi(slave);
+ unsigned int data1_reg_val;
+
+ /* enable CS hold, CS[n] and clear the data bits */
+ data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
+ (slave->cs << SPIDAT1_CSNR_SHIFT));
+
+ /* wait till TXFULL is deasserted */
+ while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
+ ;
+
+ /* preload the TX buffer to avoid clock starvation */
+ writel(data1_reg_val, &ds->regs->dat1);
+
+ /* keep reading 1 byte until only 1 byte left */
+ while ((len--) > 1)
+ *rxp++ = davinci_spi_xfer_data(ds, data1_reg_val);
+
+ /* clear CS hold when we reach the end */
+ if (flags & SPI_XFER_END)
+ data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
+
+ /* read the last byte */
+ *rxp = davinci_spi_xfer_data(ds, data1_reg_val);
+
+ return 0;
+}
+
+static int davinci_spi_write(struct spi_slave *slave, unsigned int len,
+ const u8 *txp, unsigned long flags)
+{
+ struct davinci_spi_slave *ds = to_davinci_spi(slave);
+ unsigned int data1_reg_val;
+
+ /* enable CS hold and clear the data bits */
+ data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
+ (slave->cs << SPIDAT1_CSNR_SHIFT));
+
+ /* wait till TXFULL is deasserted */
+ while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
+ ;
+
+ /* preload the TX buffer to avoid clock starvation */
+ if (len > 2) {
+ writel(data1_reg_val | *txp++, &ds->regs->dat1);
+ len--;
+ }
+
+ /* keep writing 1 byte until only 1 byte left */
+ while ((len--) > 1)
+ davinci_spi_xfer_data(ds, data1_reg_val | *txp++);
+
+ /* clear CS hold when we reach the end */
+ if (flags & SPI_XFER_END)
+ data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
+
+ /* write the last byte */
+ davinci_spi_xfer_data(ds, data1_reg_val | *txp);
+
+ return 0;
+}
+
+#ifndef CONFIG_SPI_HALF_DUPLEX
+static int davinci_spi_read_write(struct spi_slave *slave, unsigned int len,
+ u8 *rxp, const u8 *txp, unsigned long flags)
+{
+ struct davinci_spi_slave *ds = to_davinci_spi(slave);
+ unsigned int data1_reg_val;
+
+ /* enable CS hold and clear the data bits */
+ data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
+ (slave->cs << SPIDAT1_CSNR_SHIFT));
+
+ /* wait till TXFULL is deasserted */
+ while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
+ ;
+
+ /* keep reading and writing 1 byte until only 1 byte left */
+ while ((len--) > 1)
+ *rxp++ = davinci_spi_xfer_data(ds, data1_reg_val | *txp++);
+
+ /* clear CS hold when we reach the end */
+ if (flags & SPI_XFER_END)
+ data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
+
+ /* read and write the last byte */
+ *rxp = davinci_spi_xfer_data(ds, data1_reg_val | *txp);
+
+ return 0;
+}
+#endif
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ unsigned int len;
+
+ if (bitlen == 0)
+ /* Finish any previously submitted transfers */
+ goto out;
+
+ /*
+ * It's not clear how non-8-bit-aligned transfers are supposed to be
+ * represented as a stream of bytes...this is a limitation of
+ * the current SPI interface - here we terminate on receiving such a
+ * transfer request.
+ */
+ if (bitlen % 8) {
+ /* Errors always terminate an ongoing transfer */
+ flags |= SPI_XFER_END;
+ goto out;
+ }
+
+ len = bitlen / 8;
+
+ if (!dout)
+ return davinci_spi_read(slave, len, din, flags);
+ else if (!din)
+ return davinci_spi_write(slave, len, dout, flags);
+#ifndef CONFIG_SPI_HALF_DUPLEX
+ else
+ return davinci_spi_read_write(slave, len, din, dout, flags);
+#else
+ printf("SPI full duplex transaction requested with "
+ "CONFIG_SPI_HALF_DUPLEX defined.\n");
+ flags |= SPI_XFER_END;
+#endif
+
+out:
+ if (flags & SPI_XFER_END) {
+ u8 dummy = 0;
+ davinci_spi_write(slave, 1, &dummy, flags);
+ }
+ return 0;
+}
+
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+ int ret = 0;
+
+ switch (bus) {
+ case SPI0_BUS:
+ if (cs < SPI0_NUM_CS)
+ ret = 1;
+ break;
+#ifdef CONFIG_SYS_SPI1
+ case SPI1_BUS:
+ if (cs < SPI1_NUM_CS)
+ ret = 1;
+ break;
+#endif
+#ifdef CONFIG_SYS_SPI2
+ case SPI2_BUS:
+ if (cs < SPI2_NUM_CS)
+ ret = 1;
+ break;
+#endif
+ default:
+ /* Invalid bus number. Do nothing */
+ break;
+ }
+ return ret;
+}
+
+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