spi: Add Cadence QSPI DM driver used by SoCFPGA

This driver is cloned from the Altera Rockerboard.org U-Boot
repository. I used this git tag: ACDS14.0.1_REL_GSRD_RC2. With Some
modification to support the U-Boot driver model (DM).

As mentioned above, in this new version I ported this driver to the
new driver model (DM). One big advantage of this move is that now
multiple SPI drivers can be enabled on one platform. And since the
SoCFPGA also has the Designware SPI master controller integrated,
this feature is really needed to support both controllers.

Because of this, this series needs the DT support for SoCFPGA
to be applied. For DT based probing in the SPI DM.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Chin Liang See <clsee@altera.com>
Cc: Dinh Nguyen <dinguyen@altera.com>
Cc: Vince Bridgers <vbridger@altera.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Pavel Machek <pavel@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>

1 files changed, 345 insertions, 0 deletions

diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c
new file mode 100644
index 00000000000..fa95b19ecdd
--- /dev/null
+++ b/drivers/spi/cadence_qspi.c
@@ -0,0 +1,345 @@
+/*
+ * Copyright (C) 2012
+ * Altera Corporation <www.altera.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <fdtdec.h>
+#include <malloc.h>
+#include <spi.h>
+#include <asm/errno.h>
+#include "cadence_qspi.h"
+
+#define CQSPI_STIG_READ			0
+#define CQSPI_STIG_WRITE		1
+#define CQSPI_INDIRECT_READ		2
+#define CQSPI_INDIRECT_WRITE		3
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int cadence_spi_write_speed(struct udevice *bus, uint hz)
+{
+	struct cadence_spi_platdata *plat = bus->platdata;
+	struct cadence_spi_priv *priv = dev_get_priv(bus);
+
+	cadence_qspi_apb_config_baudrate_div(priv->regbase,
+					     CONFIG_CQSPI_REF_CLK, hz);
+
+	/* Reconfigure delay timing if speed is changed. */
+	cadence_qspi_apb_delay(priv->regbase, CONFIG_CQSPI_REF_CLK, hz,
+			       plat->tshsl_ns, plat->tsd2d_ns,
+			       plat->tchsh_ns, plat->tslch_ns);
+
+	return 0;
+}
+
+/* Calibration sequence to determine the read data capture delay register */
+static int spi_calibration(struct udevice *bus)
+{
+	struct cadence_spi_platdata *plat = bus->platdata;
+	struct cadence_spi_priv *priv = dev_get_priv(bus);
+	void *base = priv->regbase;
+	u8 opcode_rdid = 0x9F;
+	unsigned int idcode = 0, temp = 0;
+	int err = 0, i, range_lo = -1, range_hi = -1;
+
+	/* start with slowest clock (1 MHz) */
+	cadence_spi_write_speed(bus, 1000000);
+
+	/* configure the read data capture delay register to 0 */
+	cadence_qspi_apb_readdata_capture(base, 1, 0);
+
+	/* Enable QSPI */
+	cadence_qspi_apb_controller_enable(base);
+
+	/* read the ID which will be our golden value */
+	err = cadence_qspi_apb_command_read(base, 1, &opcode_rdid,
+		3, (u8 *)&idcode);
+	if (err) {
+		puts("SF: Calibration failed (read)\n");
+		return err;
+	}
+
+	/* use back the intended clock and find low range */
+	cadence_spi_write_speed(bus, plat->max_hz);
+	for (i = 0; i < CQSPI_READ_CAPTURE_MAX_DELAY; i++) {
+		/* Disable QSPI */
+		cadence_qspi_apb_controller_disable(base);
+
+		/* reconfigure the read data capture delay register */
+		cadence_qspi_apb_readdata_capture(base, 1, i);
+
+		/* Enable back QSPI */
+		cadence_qspi_apb_controller_enable(base);
+
+		/* issue a RDID to get the ID value */
+		err = cadence_qspi_apb_command_read(base, 1, &opcode_rdid,
+			3, (u8 *)&temp);
+		if (err) {
+			puts("SF: Calibration failed (read)\n");
+			return err;
+		}
+
+		/* search for range lo */
+		if (range_lo == -1 && temp == idcode) {
+			range_lo = i;
+			continue;
+		}
+
+		/* search for range hi */
+		if (range_lo != -1 && temp != idcode) {
+			range_hi = i - 1;
+			break;
+		}
+		range_hi = i;
+	}
+
+	if (range_lo == -1) {
+		puts("SF: Calibration failed (low range)\n");
+		return err;
+	}
+
+	/* Disable QSPI for subsequent initialization */
+	cadence_qspi_apb_controller_disable(base);
+
+	/* configure the final value for read data capture delay register */
+	cadence_qspi_apb_readdata_capture(base, 1, (range_hi + range_lo) / 2);
+	debug("SF: Read data capture delay calibrated to %i (%i - %i)\n",
+	      (range_hi + range_lo) / 2, range_lo, range_hi);
+
+	/* just to ensure we do once only when speed or chip select change */
+	priv->qspi_calibrated_hz = plat->max_hz;
+	priv->qspi_calibrated_cs = spi_chip_select(bus);
+
+	return 0;
+}
+
+static int cadence_spi_set_speed(struct udevice *bus, uint hz)
+{
+	struct cadence_spi_platdata *plat = bus->platdata;
+	struct cadence_spi_priv *priv = dev_get_priv(bus);
+	int err;
+
+	/* Disable QSPI */
+	cadence_qspi_apb_controller_disable(priv->regbase);
+
+	cadence_spi_write_speed(bus, hz);
+
+	/* Calibration required for different SCLK speed or chip select */
+	if (priv->qspi_calibrated_hz != plat->max_hz ||
+	    priv->qspi_calibrated_cs != spi_chip_select(bus)) {
+		err = spi_calibration(bus);
+		if (err)
+			return err;
+	}
+
+	/* Enable QSPI */
+	cadence_qspi_apb_controller_enable(priv->regbase);
+
+	debug("%s: speed=%d\n", __func__, hz);
+
+	return 0;
+}
+
+static int cadence_spi_probe(struct udevice *bus)
+{
+	struct cadence_spi_platdata *plat = bus->platdata;
+	struct cadence_spi_priv *priv = dev_get_priv(bus);
+
+	priv->regbase = plat->regbase;
+	priv->ahbbase = plat->ahbbase;
+
+	if (!priv->qspi_is_init) {
+		cadence_qspi_apb_controller_init(plat);
+		priv->qspi_is_init = 1;
+	}
+
+	return 0;
+}
+
+static int cadence_spi_set_mode(struct udevice *bus, uint mode)
+{
+	struct cadence_spi_priv *priv = dev_get_priv(bus);
+	unsigned int clk_pol = (mode & SPI_CPOL) ? 1 : 0;
+	unsigned int clk_pha = (mode & SPI_CPHA) ? 1 : 0;
+
+	/* Disable QSPI */
+	cadence_qspi_apb_controller_disable(priv->regbase);
+
+	/* Set SPI mode */
+	cadence_qspi_apb_set_clk_mode(priv->regbase, clk_pol, clk_pha);
+
+	/* Enable QSPI */
+	cadence_qspi_apb_controller_enable(priv->regbase);
+
+	return 0;
+}
+
+static int cadence_spi_xfer(struct udevice *dev, unsigned int bitlen,
+			    const void *dout, void *din, unsigned long flags)
+{
+	struct udevice *bus = dev->parent;
+	struct cadence_spi_platdata *plat = bus->platdata;
+	struct cadence_spi_priv *priv = dev_get_priv(bus);
+	void *base = priv->regbase;
+	u8 *cmd_buf = priv->cmd_buf;
+	size_t data_bytes;
+	int err = 0;
+	u32 mode = CQSPI_STIG_WRITE;
+
+	if (flags & SPI_XFER_BEGIN) {
+		/* copy command to local buffer */
+		priv->cmd_len = bitlen / 8;
+		memcpy(cmd_buf, dout, priv->cmd_len);
+	}
+
+	if (flags == (SPI_XFER_BEGIN | SPI_XFER_END)) {
+		/* if start and end bit are set, the data bytes is 0. */
+		data_bytes = 0;
+	} else {
+		data_bytes = bitlen / 8;
+	}
+	debug("%s: len=%d [bytes]\n", __func__, data_bytes);
+
+	/* Set Chip select */
+	cadence_qspi_apb_chipselect(base, spi_chip_select(dev),
+				    CONFIG_CQSPI_DECODER);
+
+	if ((flags & SPI_XFER_END) || (flags == 0)) {
+		if (priv->cmd_len == 0) {
+			printf("QSPI: Error, command is empty.\n");
+			return -1;
+		}
+
+		if (din && data_bytes) {
+			/* read */
+			/* Use STIG if no address. */
+			if (!CQSPI_IS_ADDR(priv->cmd_len))
+				mode = CQSPI_STIG_READ;
+			else
+				mode = CQSPI_INDIRECT_READ;
+		} else if (dout && !(flags & SPI_XFER_BEGIN)) {
+			/* write */
+			if (!CQSPI_IS_ADDR(priv->cmd_len))
+				mode = CQSPI_STIG_WRITE;
+			else
+				mode = CQSPI_INDIRECT_WRITE;
+		}
+
+		switch (mode) {
+		case CQSPI_STIG_READ:
+			err = cadence_qspi_apb_command_read(
+				base, priv->cmd_len, cmd_buf,
+				data_bytes, din);
+
+		break;
+		case CQSPI_STIG_WRITE:
+			err = cadence_qspi_apb_command_write(base,
+				priv->cmd_len, cmd_buf,
+				data_bytes, dout);
+		break;
+		case CQSPI_INDIRECT_READ:
+			err = cadence_qspi_apb_indirect_read_setup(plat,
+				priv->cmd_len, cmd_buf);
+			if (!err) {
+				err = cadence_qspi_apb_indirect_read_execute
+				(plat, data_bytes, din);
+			}
+		break;
+		case CQSPI_INDIRECT_WRITE:
+			err = cadence_qspi_apb_indirect_write_setup
+				(plat, priv->cmd_len, cmd_buf);
+			if (!err) {
+				err = cadence_qspi_apb_indirect_write_execute
+				(plat, data_bytes, dout);
+			}
+		break;
+		default:
+			err = -1;
+			break;
+		}
+
+		if (flags & SPI_XFER_END) {
+			/* clear command buffer */
+			memset(cmd_buf, 0, sizeof(priv->cmd_buf));
+			priv->cmd_len = 0;
+		}
+	}
+
+	return err;
+}
+
+static int cadence_spi_ofdata_to_platdata(struct udevice *bus)
+{
+	struct cadence_spi_platdata *plat = bus->platdata;
+	const void *blob = gd->fdt_blob;
+	int node = bus->of_offset;
+	int subnode;
+	u32 data[4];
+	int ret;
+
+	/* 2 base addresses are needed, lets get them from the DT */
+	ret = fdtdec_get_int_array(blob, node, "reg", data, ARRAY_SIZE(data));
+	if (ret) {
+		printf("Error: Can't get base addresses (ret=%d)!\n", ret);
+		return -ENODEV;
+	}
+
+	plat->regbase = (void *)data[0];
+	plat->ahbbase = (void *)data[2];
+
+	/* Use 500KHz as a suitable default */
+	plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency",
+				      500000);
+
+	/* All other paramters are embedded in the child node */
+	subnode = fdt_first_subnode(blob, node);
+	if (!subnode) {
+		printf("Error: subnode with SPI flash config missing!\n");
+		return -ENODEV;
+	}
+
+	/* Read other parameters from DT */
+	plat->page_size = fdtdec_get_int(blob, subnode, "page-size", 256);
+	plat->block_size = fdtdec_get_int(blob, subnode, "block-size", 16);
+	plat->tshsl_ns = fdtdec_get_int(blob, subnode, "tshsl-ns", 200);
+	plat->tsd2d_ns = fdtdec_get_int(blob, subnode, "tsd2d-ns", 255);
+	plat->tchsh_ns = fdtdec_get_int(blob, subnode, "tchsh-ns", 20);
+	plat->tslch_ns = fdtdec_get_int(blob, subnode, "tslch-ns", 20);
+
+	debug("%s: regbase=%p ahbbase=%p max-frequency=%d page-size=%d\n",
+	      __func__, plat->regbase, plat->ahbbase, plat->max_hz,
+	      plat->page_size);
+
+	return 0;
+}
+
+static const struct dm_spi_ops cadence_spi_ops = {
+	.xfer		= cadence_spi_xfer,
+	.set_speed	= cadence_spi_set_speed,
+	.set_mode	= cadence_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 cadence_spi_ids[] = {
+	{ .compatible = "cadence,qspi" },
+	{ }
+};
+
+U_BOOT_DRIVER(cadence_spi) = {
+	.name = "cadence_spi",
+	.id = UCLASS_SPI,
+	.of_match = cadence_spi_ids,
+	.ops = &cadence_spi_ops,
+	.ofdata_to_platdata = cadence_spi_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct cadence_spi_platdata),
+	.priv_auto_alloc_size = sizeof(struct cadence_spi_priv),
+	.per_child_auto_alloc_size = sizeof(struct spi_slave),
+	.probe = cadence_spi_probe,
+};