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* Copyright (c) 2010-2013 NVIDIA Corporation
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* With help from the mpc8xxx SPI driver
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* With more help from omap3_spi SPI driver
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* SPDX-License-Identifier: GPL-2.0+
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#include <asm/arch/clock.h>
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#include <asm/arch/pinmux.h>
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#include <asm/arch-tegra/clk_rst.h>
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#include <asm/arch-tegra20/tegra20_sflash.h>
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DECLARE_GLOBAL_DATA_PTR;
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#define SPI_CMD_GO (1 << 30)
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#define SPI_CMD_ACTIVE_SCLK_SHIFT 26
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#define SPI_CMD_ACTIVE_SCLK_MASK (3 << SPI_CMD_ACTIVE_SCLK_SHIFT)
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#define SPI_CMD_CK_SDA (1 << 21)
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#define SPI_CMD_ACTIVE_SDA_SHIFT 18
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#define SPI_CMD_ACTIVE_SDA_MASK (3 << SPI_CMD_ACTIVE_SDA_SHIFT)
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#define SPI_CMD_CS_POL (1 << 16)
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#define SPI_CMD_TXEN (1 << 15)
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#define SPI_CMD_RXEN (1 << 14)
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#define SPI_CMD_CS_VAL (1 << 13)
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#define SPI_CMD_CS_SOFT (1 << 12)
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#define SPI_CMD_CS_DELAY (1 << 9)
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#define SPI_CMD_CS3_EN (1 << 8)
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#define SPI_CMD_CS2_EN (1 << 7)
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#define SPI_CMD_CS1_EN (1 << 6)
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#define SPI_CMD_CS0_EN (1 << 5)
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#define SPI_CMD_BIT_LENGTH (1 << 4)
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#define SPI_CMD_BIT_LENGTH_MASK 0x0000001F
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#define SPI_STAT_BSY (1 << 31)
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#define SPI_STAT_RDY (1 << 30)
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#define SPI_STAT_RXF_FLUSH (1 << 29)
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#define SPI_STAT_TXF_FLUSH (1 << 28)
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#define SPI_STAT_RXF_UNR (1 << 27)
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#define SPI_STAT_TXF_OVF (1 << 26)
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#define SPI_STAT_RXF_EMPTY (1 << 25)
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#define SPI_STAT_RXF_FULL (1 << 24)
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#define SPI_STAT_TXF_EMPTY (1 << 23)
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#define SPI_STAT_TXF_FULL (1 << 22)
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#define SPI_STAT_SEL_TXRX_N (1 << 16)
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#define SPI_STAT_CUR_BLKCNT (1 << 15)
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#define SPI_TIMEOUT 1000
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#define TEGRA_SPI_MAX_FREQ 52000000
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u32 command; /* SPI_COMMAND_0 register */
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u32 status; /* SPI_STATUS_0 register */
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u32 rx_cmp; /* SPI_RX_CMP_0 register */
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u32 dma_ctl; /* SPI_DMA_CTL_0 register */
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u32 tx_fifo; /* SPI_TX_FIFO_0 register */
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u32 rsvd[3]; /* offsets 0x14 to 0x1F reserved */
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u32 rx_fifo; /* SPI_RX_FIFO_0 register */
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struct tegra_spi_ctrl {
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struct spi_regs *regs;
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struct tegra_spi_slave {
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struct spi_slave slave;
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struct tegra_spi_ctrl *ctrl;
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/* tegra20 only supports one SFLASH controller */
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static struct tegra_spi_ctrl spi_ctrls[1];
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static inline struct tegra_spi_slave *to_tegra_spi(struct spi_slave *slave)
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return container_of(slave, struct tegra_spi_slave, slave);
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int tegra20_spi_cs_is_valid(unsigned int bus, unsigned int cs)
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/* Tegra20 SPI-Flash - only 1 device ('bus/cs') */
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if (bus != 0 || cs != 0)
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struct spi_slave *tegra20_spi_setup_slave(unsigned int bus, unsigned int cs,
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unsigned int max_hz, unsigned int mode)
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struct tegra_spi_slave *spi;
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if (!spi_cs_is_valid(bus, cs)) {
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printf("SPI error: unsupported bus %d / chip select %d\n",
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if (max_hz > TEGRA_SPI_MAX_FREQ) {
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printf("SPI error: unsupported frequency %d Hz. Max frequency"
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" is %d Hz\n", max_hz, TEGRA_SPI_MAX_FREQ);
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spi = spi_alloc_slave(struct tegra_spi_slave, bus, cs);
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printf("SPI error: malloc of SPI structure failed\n");
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spi->ctrl = &spi_ctrls[bus];
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printf("SPI error: could not find controller for bus %d\n",
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if (max_hz < spi->ctrl->freq) {
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debug("%s: limiting frequency from %u to %u\n", __func__,
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spi->ctrl->freq, max_hz);
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spi->ctrl->freq = max_hz;
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spi->ctrl->mode = mode;
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void tegra20_spi_free_slave(struct spi_slave *slave)
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struct tegra_spi_slave *spi = to_tegra_spi(slave);
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int tegra20_spi_init(int *node_list, int count)
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struct tegra_spi_ctrl *ctrl;
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for (i = 0; i < count; i++) {
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ctrl = &spi_ctrls[i];
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ctrl->regs = (struct spi_regs *)fdtdec_get_addr(gd->fdt_blob,
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if ((fdt_addr_t)ctrl->regs == FDT_ADDR_T_NONE) {
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debug("%s: no slink register found\n", __func__);
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ctrl->freq = fdtdec_get_int(gd->fdt_blob, node,
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"spi-max-frequency", 0);
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debug("%s: no slink max frequency found\n", __func__);
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ctrl->periph_id = clock_decode_periph_id(gd->fdt_blob, node);
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if (ctrl->periph_id == PERIPH_ID_NONE) {
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debug("%s: could not decode periph id\n", __func__);
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debug("%s: found controller at %p, freq = %u, periph_id = %d\n",
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__func__, ctrl->regs, ctrl->freq, ctrl->periph_id);
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int tegra20_spi_claim_bus(struct spi_slave *slave)
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struct tegra_spi_slave *spi = to_tegra_spi(slave);
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struct spi_regs *regs = spi->ctrl->regs;
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/* Change SPI clock to correct frequency, PLLP_OUT0 source */
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clock_start_periph_pll(spi->ctrl->periph_id, CLOCK_ID_PERIPH,
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/* Clear stale status here */
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reg = SPI_STAT_RDY | SPI_STAT_RXF_FLUSH | SPI_STAT_TXF_FLUSH | \
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SPI_STAT_RXF_UNR | SPI_STAT_TXF_OVF;
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writel(reg, ®s->status);
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debug("%s: STATUS = %08x\n", __func__, readl(®s->status));
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* Use sw-controlled CS, so we can clock in data after ReadID, etc.
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reg = (spi->ctrl->mode & 1) << SPI_CMD_ACTIVE_SDA_SHIFT;
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if (spi->ctrl->mode & 2)
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reg |= 1 << SPI_CMD_ACTIVE_SCLK_SHIFT;
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clrsetbits_le32(®s->command, SPI_CMD_ACTIVE_SCLK_MASK |
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SPI_CMD_ACTIVE_SDA_MASK, SPI_CMD_CS_SOFT | reg);
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debug("%s: COMMAND = %08x\n", __func__, readl(®s->command));
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* SPI pins on Tegra20 are muxed - change pinmux later due to UART
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pinmux_set_func(PMUX_PINGRP_GMD, PMUX_FUNC_SFLASH);
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pinmux_tristate_disable(PMUX_PINGRP_LSPI);
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pinmux_set_func(PMUX_PINGRP_GMC, PMUX_FUNC_SFLASH);
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void tegra20_spi_cs_activate(struct spi_slave *slave)
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struct tegra_spi_slave *spi = to_tegra_spi(slave);
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struct spi_regs *regs = spi->ctrl->regs;
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/* CS is negated on Tegra, so drive a 1 to get a 0 */
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setbits_le32(®s->command, SPI_CMD_CS_VAL);
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void tegra20_spi_cs_deactivate(struct spi_slave *slave)
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struct tegra_spi_slave *spi = to_tegra_spi(slave);
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struct spi_regs *regs = spi->ctrl->regs;
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/* CS is negated on Tegra, so drive a 0 to get a 1 */
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clrbits_le32(®s->command, SPI_CMD_CS_VAL);
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int tegra20_spi_xfer(struct spi_slave *slave, unsigned int bitlen,
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const void *data_out, void *data_in, unsigned long flags)
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struct tegra_spi_slave *spi = to_tegra_spi(slave);
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struct spi_regs *regs = spi->ctrl->regs;
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u32 reg, tmpdout, tmpdin = 0;
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const u8 *dout = data_out;
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debug("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
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slave->bus, slave->cs, *(u8 *)dout, *(u8 *)din, bitlen);
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num_bytes = bitlen / 8;
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reg = readl(®s->status);
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writel(reg, ®s->status); /* Clear all SPI events via R/W */
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debug("spi_xfer entry: STATUS = %08x\n", reg);
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reg = readl(®s->command);
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reg |= SPI_CMD_TXEN | SPI_CMD_RXEN;
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writel(reg, ®s->command);
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debug("spi_xfer: COMMAND = %08x\n", readl(®s->command));
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if (flags & SPI_XFER_BEGIN)
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spi_cs_activate(slave);
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/* handle data in 32-bit chunks */
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while (num_bytes > 0) {
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bytes = (num_bytes > 4) ? 4 : num_bytes;
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for (i = 0; i < bytes; ++i)
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tmpdout = (tmpdout << 8) | dout[i];
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clrsetbits_le32(®s->command, SPI_CMD_BIT_LENGTH_MASK,
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writel(tmpdout, ®s->tx_fifo);
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setbits_le32(®s->command, SPI_CMD_GO);
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* Wait for SPI transmit FIFO to empty, or to time out.
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* The RX FIFO status will be read and cleared last
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for (tm = 0, is_read = 0; tm < SPI_TIMEOUT; ++tm) {
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status = readl(®s->status);
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/* We can exit when we've had both RX and TX activity */
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if (is_read && (status & SPI_STAT_TXF_EMPTY))
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if ((status & (SPI_STAT_BSY | SPI_STAT_RDY)) !=
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else if (!(status & SPI_STAT_RXF_EMPTY)) {
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tmpdin = readl(®s->rx_fifo);
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/* swap bytes read in */
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for (i = bytes - 1; i >= 0; --i) {
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din[i] = tmpdin & 0xff;
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if (tm >= SPI_TIMEOUT)
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/* clear ACK RDY, etc. bits */
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writel(readl(®s->status), ®s->status);
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if (flags & SPI_XFER_END)
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spi_cs_deactivate(slave);
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debug("spi_xfer: transfer ended. Value=%08x, status = %08x\n",
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tmpdin, readl(®s->status));
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printf("spi_xfer: timeout during SPI transfer, tm %d\n", ret);