--- /dev/null
+/*
+ * Copyright (C) 2015 Marvell International Ltd.
+ *
+ * Copyright (C) 2016 Stefan Roese <sr@denx.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <malloc.h>
+#include <spi.h>
+#include <wait_bit.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define MVEBU_SPI_A3700_XFER_RDY BIT(1)
+#define MVEBU_SPI_A3700_FIFO_FLUSH BIT(9)
+#define MVEBU_SPI_A3700_BYTE_LEN BIT(5)
+#define MVEBU_SPI_A3700_CLK_PHA BIT(6)
+#define MVEBU_SPI_A3700_CLK_POL BIT(7)
+#define MVEBU_SPI_A3700_FIFO_EN BIT(17)
+#define MVEBU_SPI_A3700_SPI_EN_0 BIT(16)
+#define MVEBU_SPI_A3700_CLK_PRESCALE_BIT 0
+#define MVEBU_SPI_A3700_CLK_PRESCALE_MASK \
+ (0x1f << MVEBU_SPI_A3700_CLK_PRESCALE_BIT)
+
+/* SPI registers */
+struct spi_reg {
+ u32 ctrl; /* 0x10600 */
+ u32 cfg; /* 0x10604 */
+ u32 dout; /* 0x10608 */
+ u32 din; /* 0x1060c */
+};
+
+struct mvebu_spi_platdata {
+ struct spi_reg *spireg;
+ unsigned int frequency;
+ unsigned int clock;
+};
+
+static void spi_cs_activate(struct spi_reg *reg, int cs)
+{
+ setbits_le32(®->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs);
+}
+
+static void spi_cs_deactivate(struct spi_reg *reg, int cs)
+{
+ clrbits_le32(®->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs);
+}
+
+/**
+ * spi_legacy_shift_byte() - triggers the real SPI transfer
+ * @bytelen: Indicate how many bytes to transfer.
+ * @dout: Buffer address of what to send.
+ * @din: Buffer address of where to receive.
+ *
+ * This function triggers the real SPI transfer in legacy mode. It
+ * will shift out char buffer from @dout, and shift in char buffer to
+ * @din, if necessary.
+ *
+ * This function assumes that only one byte is shifted at one time.
+ * However, it is not its responisbility to set the transfer type to
+ * one-byte. Also, it does not guarantee that it will work if transfer
+ * type becomes two-byte. See spi_set_legacy() for details.
+ *
+ * In legacy mode, simply write to the SPI_DOUT register will trigger
+ * the transfer.
+ *
+ * If @dout == NULL, which means no actual data needs to be sent out,
+ * then the function will shift out 0x00 in order to shift in data.
+ * The XFER_RDY flag is checked every time before accessing SPI_DOUT
+ * and SPI_DIN register.
+ *
+ * The number of transfers to be triggerred is decided by @bytelen.
+ *
+ * Return: 0 - cool
+ * -ETIMEDOUT - XFER_RDY flag timeout
+ */
+static int spi_legacy_shift_byte(struct spi_reg *reg, unsigned int bytelen,
+ const void *dout, void *din)
+{
+ const u8 *dout_8;
+ u8 *din_8;
+ int ret;
+
+ /* Use 0x00 as dummy dout */
+ const u8 dummy_dout = 0x0;
+ u32 pending_dout = 0x0;
+
+ /* dout_8: pointer of current dout */
+ dout_8 = dout;
+ /* din_8: pointer of current din */
+ din_8 = din;
+
+ while (bytelen) {
+ ret = wait_for_bit(__func__, ®->ctrl,
+ MVEBU_SPI_A3700_XFER_RDY, true, 100, false);
+ if (ret)
+ return ret;
+
+ if (dout)
+ pending_dout = (u32)*dout_8;
+ else
+ pending_dout = (u32)dummy_dout;
+
+ /* Trigger the xfer */
+ writel(pending_dout, ®->dout);
+
+ if (din) {
+ ret = wait_for_bit(__func__, ®->ctrl,
+ MVEBU_SPI_A3700_XFER_RDY,
+ true, 100, false);
+ if (ret)
+ return ret;
+
+ /* Read what is transferred in */
+ *din_8 = (u8)readl(®->din);
+ }
+
+ /* Don't increment the current pointer if NULL */
+ if (dout)
+ dout_8++;
+ if (din)
+ din_8++;
+
+ bytelen--;
+ }
+
+ return 0;
+}
+
+static int mvebu_spi_xfer(struct udevice *dev, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ struct udevice *bus = dev->parent;
+ struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
+ struct spi_reg *reg = plat->spireg;
+ unsigned int bytelen;
+ int ret;
+
+ bytelen = bitlen / 8;
+
+ if (dout && din)
+ debug("This is a duplex transfer.\n");
+
+ /* Activate CS */
+ if (flags & SPI_XFER_BEGIN) {
+ debug("SPI: activate cs.\n");
+ spi_cs_activate(reg, spi_chip_select(dev));
+ }
+
+ /* Send and/or receive */
+ if (dout || din) {
+ ret = spi_legacy_shift_byte(reg, bytelen, dout, din);
+ if (ret)
+ return ret;
+ }
+
+ /* Deactivate CS */
+ if (flags & SPI_XFER_END) {
+ ret = wait_for_bit(__func__, ®->ctrl,
+ MVEBU_SPI_A3700_XFER_RDY, true, 100, false);
+ if (ret)
+ return ret;
+
+ debug("SPI: deactivate cs.\n");
+ spi_cs_deactivate(reg, spi_chip_select(dev));
+ }
+
+ return 0;
+}
+
+static int mvebu_spi_set_speed(struct udevice *bus, uint hz)
+{
+ struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
+ struct spi_reg *reg = plat->spireg;
+ u32 data;
+
+ data = readl(®->cfg);
+
+ /* Set Prescaler */
+ data &= ~MVEBU_SPI_A3700_CLK_PRESCALE_MASK;
+
+ /* Calculate Prescaler = (spi_input_freq / spi_max_freq) */
+ if (hz > plat->frequency)
+ hz = plat->frequency;
+ data |= plat->clock / hz;
+
+ writel(data, ®->cfg);
+
+ return 0;
+}
+
+static int mvebu_spi_set_mode(struct udevice *bus, uint mode)
+{
+ struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
+ struct spi_reg *reg = plat->spireg;
+
+ /*
+ * Set SPI polarity
+ * 0: Serial interface clock is low when inactive
+ * 1: Serial interface clock is high when inactive
+ */
+ if (mode & SPI_CPOL)
+ setbits_le32(®->cfg, MVEBU_SPI_A3700_CLK_POL);
+ else
+ clrbits_le32(®->cfg, MVEBU_SPI_A3700_CLK_POL);
+ if (mode & SPI_CPHA)
+ setbits_le32(®->cfg, MVEBU_SPI_A3700_CLK_PHA);
+ else
+ clrbits_le32(®->cfg, MVEBU_SPI_A3700_CLK_PHA);
+
+ return 0;
+}
+
+static int mvebu_spi_probe(struct udevice *bus)
+{
+ struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
+ struct spi_reg *reg = plat->spireg;
+ u32 data;
+ int ret;
+
+ /*
+ * Settings SPI controller to be working in legacy mode, which
+ * means use only DO pin (I/O 1) for Data Out, and DI pin (I/O 0)
+ * for Data In.
+ */
+
+ /* Flush read/write FIFO */
+ data = readl(®->cfg);
+ writel(data | MVEBU_SPI_A3700_FIFO_FLUSH, ®->cfg);
+ ret = wait_for_bit(__func__, ®->cfg, MVEBU_SPI_A3700_FIFO_FLUSH,
+ false, 1000, false);
+ if (ret)
+ return ret;
+
+ /* Disable FIFO mode */
+ data &= ~MVEBU_SPI_A3700_FIFO_EN;
+
+ /* Always shift 1 byte at a time */
+ data &= ~MVEBU_SPI_A3700_BYTE_LEN;
+
+ writel(data, ®->cfg);
+
+ return 0;
+}
+
+static int mvebu_spi_ofdata_to_platdata(struct udevice *bus)
+{
+ struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
+
+ plat->spireg = (struct spi_reg *)dev_get_addr(bus);
+
+ /*
+ * FIXME
+ * Right now, mvebu does not have a clock infrastructure in U-Boot
+ * which should be used to query the input clock to the SPI
+ * controller. Once this clock driver is integrated into U-Boot
+ * it should be used to read the input clock and the DT property
+ * can be removed.
+ */
+ plat->clock = fdtdec_get_int(gd->fdt_blob, bus->of_offset,
+ "clock-frequency", 160000);
+ plat->frequency = fdtdec_get_int(gd->fdt_blob, bus->of_offset,
+ "spi-max-frequency", 40000);
+
+ return 0;
+}
+
+static const struct dm_spi_ops mvebu_spi_ops = {
+ .xfer = mvebu_spi_xfer,
+ .set_speed = mvebu_spi_set_speed,
+ .set_mode = mvebu_spi_set_mode,
+ /*
+ * cs_info is not needed, since we require all chip selects to be
+ * in the device tree explicitly
+ */
+};
+
+static const struct udevice_id mvebu_spi_ids[] = {
+ { .compatible = "marvell,armada-3700-spi" },
+ { }
+};
+
+U_BOOT_DRIVER(mvebu_spi) = {
+ .name = "mvebu_spi",
+ .id = UCLASS_SPI,
+ .of_match = mvebu_spi_ids,
+ .ops = &mvebu_spi_ops,
+ .ofdata_to_platdata = mvebu_spi_ofdata_to_platdata,
+ .platdata_auto_alloc_size = sizeof(struct mvebu_spi_platdata),
+ .probe = mvebu_spi_probe,
+};
projects / u-boot.git / commitdiff