spi: Add Atmel QuadSPI driver

Backport the driver from linux v5.1-rc5 and adapt it for u-boot.
Tested on sama5d2_xplained Rev B with mx25l25635e spi-nor flash.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>

1 files changed, 536 insertions, 0 deletions

diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
new file mode 100644
index 0000000000..7d9a54011d
--- /dev/null
+++ b/drivers/spi/atmel-quadspi.c
@@ -0,0 +1,536 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Atmel QSPI Controller
+ *
+ * Copyright (C) 2015 Atmel Corporation
+ * Copyright (C) 2018 Cryptera A/S
+ *
+ * Author: Cyrille Pitchen <cyrille.pitchen@atmel.com>
+ * Author: Piotr Bugalski <bugalski.piotr@gmail.com>
+ */
+
+#include <asm/io.h>
+#include <clk.h>
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/ioport.h>
+#include <mach/clk.h>
+#include <spi.h>
+#include <spi-mem.h>
+
+/* QSPI register offsets */
+#define QSPI_CR      0x0000  /* Control Register */
+#define QSPI_MR      0x0004  /* Mode Register */
+#define QSPI_RD      0x0008  /* Receive Data Register */
+#define QSPI_TD      0x000c  /* Transmit Data Register */
+#define QSPI_SR      0x0010  /* Status Register */
+#define QSPI_IER     0x0014  /* Interrupt Enable Register */
+#define QSPI_IDR     0x0018  /* Interrupt Disable Register */
+#define QSPI_IMR     0x001c  /* Interrupt Mask Register */
+#define QSPI_SCR     0x0020  /* Serial Clock Register */
+
+#define QSPI_IAR     0x0030  /* Instruction Address Register */
+#define QSPI_ICR     0x0034  /* Instruction Code Register */
+#define QSPI_WICR    0x0034  /* Write Instruction Code Register */
+#define QSPI_IFR     0x0038  /* Instruction Frame Register */
+#define QSPI_RICR    0x003C  /* Read Instruction Code Register */
+
+#define QSPI_SMR     0x0040  /* Scrambling Mode Register */
+#define QSPI_SKR     0x0044  /* Scrambling Key Register */
+
+#define QSPI_WPMR    0x00E4  /* Write Protection Mode Register */
+#define QSPI_WPSR    0x00E8  /* Write Protection Status Register */
+
+#define QSPI_VERSION 0x00FC  /* Version Register */
+
+/* Bitfields in QSPI_CR (Control Register) */
+#define QSPI_CR_QSPIEN                  BIT(0)
+#define QSPI_CR_QSPIDIS                 BIT(1)
+#define QSPI_CR_SWRST                   BIT(7)
+#define QSPI_CR_LASTXFER                BIT(24)
+
+/* Bitfields in QSPI_MR (Mode Register) */
+#define QSPI_MR_SMM                     BIT(0)
+#define QSPI_MR_LLB                     BIT(1)
+#define QSPI_MR_WDRBT                   BIT(2)
+#define QSPI_MR_SMRM                    BIT(3)
+#define QSPI_MR_CSMODE_MASK             GENMASK(5, 4)
+#define QSPI_MR_CSMODE_NOT_RELOADED     (0 << 4)
+#define QSPI_MR_CSMODE_LASTXFER         (1 << 4)
+#define QSPI_MR_CSMODE_SYSTEMATICALLY   (2 << 4)
+#define QSPI_MR_NBBITS_MASK             GENMASK(11, 8)
+#define QSPI_MR_NBBITS(n)               ((((n) - 8) << 8) & QSPI_MR_NBBITS_MASK)
+#define QSPI_MR_DLYBCT_MASK             GENMASK(23, 16)
+#define QSPI_MR_DLYBCT(n)               (((n) << 16) & QSPI_MR_DLYBCT_MASK)
+#define QSPI_MR_DLYCS_MASK              GENMASK(31, 24)
+#define QSPI_MR_DLYCS(n)                (((n) << 24) & QSPI_MR_DLYCS_MASK)
+
+/* Bitfields in QSPI_SR/QSPI_IER/QSPI_IDR/QSPI_IMR  */
+#define QSPI_SR_RDRF                    BIT(0)
+#define QSPI_SR_TDRE                    BIT(1)
+#define QSPI_SR_TXEMPTY                 BIT(2)
+#define QSPI_SR_OVRES                   BIT(3)
+#define QSPI_SR_CSR                     BIT(8)
+#define QSPI_SR_CSS                     BIT(9)
+#define QSPI_SR_INSTRE                  BIT(10)
+#define QSPI_SR_QSPIENS                 BIT(24)
+
+#define QSPI_SR_CMD_COMPLETED	(QSPI_SR_INSTRE | QSPI_SR_CSR)
+
+/* Bitfields in QSPI_SCR (Serial Clock Register) */
+#define QSPI_SCR_CPOL                   BIT(0)
+#define QSPI_SCR_CPHA                   BIT(1)
+#define QSPI_SCR_SCBR_MASK              GENMASK(15, 8)
+#define QSPI_SCR_SCBR(n)                (((n) << 8) & QSPI_SCR_SCBR_MASK)
+#define QSPI_SCR_DLYBS_MASK             GENMASK(23, 16)
+#define QSPI_SCR_DLYBS(n)               (((n) << 16) & QSPI_SCR_DLYBS_MASK)
+
+/* Bitfields in QSPI_ICR (Read/Write Instruction Code Register) */
+#define QSPI_ICR_INST_MASK              GENMASK(7, 0)
+#define QSPI_ICR_INST(inst)             (((inst) << 0) & QSPI_ICR_INST_MASK)
+#define QSPI_ICR_OPT_MASK               GENMASK(23, 16)
+#define QSPI_ICR_OPT(opt)               (((opt) << 16) & QSPI_ICR_OPT_MASK)
+
+/* Bitfields in QSPI_IFR (Instruction Frame Register) */
+#define QSPI_IFR_WIDTH_MASK             GENMASK(2, 0)
+#define QSPI_IFR_WIDTH_SINGLE_BIT_SPI   (0 << 0)
+#define QSPI_IFR_WIDTH_DUAL_OUTPUT      (1 << 0)
+#define QSPI_IFR_WIDTH_QUAD_OUTPUT      (2 << 0)
+#define QSPI_IFR_WIDTH_DUAL_IO          (3 << 0)
+#define QSPI_IFR_WIDTH_QUAD_IO          (4 << 0)
+#define QSPI_IFR_WIDTH_DUAL_CMD         (5 << 0)
+#define QSPI_IFR_WIDTH_QUAD_CMD         (6 << 0)
+#define QSPI_IFR_INSTEN                 BIT(4)
+#define QSPI_IFR_ADDREN                 BIT(5)
+#define QSPI_IFR_OPTEN                  BIT(6)
+#define QSPI_IFR_DATAEN                 BIT(7)
+#define QSPI_IFR_OPTL_MASK              GENMASK(9, 8)
+#define QSPI_IFR_OPTL_1BIT              (0 << 8)
+#define QSPI_IFR_OPTL_2BIT              (1 << 8)
+#define QSPI_IFR_OPTL_4BIT              (2 << 8)
+#define QSPI_IFR_OPTL_8BIT              (3 << 8)
+#define QSPI_IFR_ADDRL                  BIT(10)
+#define QSPI_IFR_TFRTYP_MEM		BIT(12)
+#define QSPI_IFR_SAMA5D2_WRITE_TRSFR	BIT(13)
+#define QSPI_IFR_CRM                    BIT(14)
+#define QSPI_IFR_NBDUM_MASK             GENMASK(20, 16)
+#define QSPI_IFR_NBDUM(n)               (((n) << 16) & QSPI_IFR_NBDUM_MASK)
+#define QSPI_IFR_APBTFRTYP_READ		BIT(24)	/* Defined in SAM9X60 */
+
+/* Bitfields in QSPI_SMR (Scrambling Mode Register) */
+#define QSPI_SMR_SCREN                  BIT(0)
+#define QSPI_SMR_RVDIS                  BIT(1)
+
+/* Bitfields in QSPI_WPMR (Write Protection Mode Register) */
+#define QSPI_WPMR_WPEN                  BIT(0)
+#define QSPI_WPMR_WPKEY_MASK            GENMASK(31, 8)
+#define QSPI_WPMR_WPKEY(wpkey)          (((wpkey) << 8) & QSPI_WPMR_WPKEY_MASK)
+
+/* Bitfields in QSPI_WPSR (Write Protection Status Register) */
+#define QSPI_WPSR_WPVS                  BIT(0)
+#define QSPI_WPSR_WPVSRC_MASK           GENMASK(15, 8)
+#define QSPI_WPSR_WPVSRC(src)           (((src) << 8) & QSPI_WPSR_WPVSRC)
+
+struct atmel_qspi_caps {
+	bool has_qspick;
+	bool has_ricr;
+};
+
+struct atmel_qspi {
+	void __iomem *regs;
+	void __iomem *mem;
+	const struct atmel_qspi_caps *caps;
+	ulong bus_clk_rate;
+	u32 mr;
+};
+
+struct atmel_qspi_mode {
+	u8 cmd_buswidth;
+	u8 addr_buswidth;
+	u8 data_buswidth;
+	u32 config;
+};
+
+static const struct atmel_qspi_mode atmel_qspi_modes[] = {
+	{ 1, 1, 1, QSPI_IFR_WIDTH_SINGLE_BIT_SPI },
+	{ 1, 1, 2, QSPI_IFR_WIDTH_DUAL_OUTPUT },
+	{ 1, 1, 4, QSPI_IFR_WIDTH_QUAD_OUTPUT },
+	{ 1, 2, 2, QSPI_IFR_WIDTH_DUAL_IO },
+	{ 1, 4, 4, QSPI_IFR_WIDTH_QUAD_IO },
+	{ 2, 2, 2, QSPI_IFR_WIDTH_DUAL_CMD },
+	{ 4, 4, 4, QSPI_IFR_WIDTH_QUAD_CMD },
+};
+
+static inline bool atmel_qspi_is_compatible(const struct spi_mem_op *op,
+					    const struct atmel_qspi_mode *mode)
+{
+	if (op->cmd.buswidth != mode->cmd_buswidth)
+		return false;
+
+	if (op->addr.nbytes && op->addr.buswidth != mode->addr_buswidth)
+		return false;
+
+	if (op->data.nbytes && op->data.buswidth != mode->data_buswidth)
+		return false;
+
+	return true;
+}
+
+static int atmel_qspi_find_mode(const struct spi_mem_op *op)
+{
+	u32 i;
+
+	for (i = 0; i < ARRAY_SIZE(atmel_qspi_modes); i++)
+		if (atmel_qspi_is_compatible(op, &atmel_qspi_modes[i]))
+			return i;
+
+	return -ENOTSUPP;
+}
+
+static bool atmel_qspi_supports_op(struct spi_slave *slave,
+				   const struct spi_mem_op *op)
+{
+	if (atmel_qspi_find_mode(op) < 0)
+		return false;
+
+	/* special case not supported by hardware */
+	if (op->addr.nbytes == 2 && op->cmd.buswidth != op->addr.buswidth &&
+	    op->dummy.nbytes == 0)
+		return false;
+
+	return true;
+}
+
+static int atmel_qspi_set_cfg(struct atmel_qspi *aq,
+			      const struct spi_mem_op *op, u32 *offset)
+{
+	u32 iar, icr, ifr;
+	u32 dummy_cycles = 0;
+	int mode;
+
+	iar = 0;
+	icr = QSPI_ICR_INST(op->cmd.opcode);
+	ifr = QSPI_IFR_INSTEN;
+
+	mode = atmel_qspi_find_mode(op);
+	if (mode < 0)
+		return mode;
+	ifr |= atmel_qspi_modes[mode].config;
+
+	if (op->dummy.buswidth && op->dummy.nbytes)
+		dummy_cycles = op->dummy.nbytes * 8 / op->dummy.buswidth;
+
+	/*
+	 * The controller allows 24 and 32-bit addressing while NAND-flash
+	 * requires 16-bit long. Handling 8-bit long addresses is done using
+	 * the option field. For the 16-bit addresses, the workaround depends
+	 * of the number of requested dummy bits. If there are 8 or more dummy
+	 * cycles, the address is shifted and sent with the first dummy byte.
+	 * Otherwise opcode is disabled and the first byte of the address
+	 * contains the command opcode (works only if the opcode and address
+	 * use the same buswidth). The limitation is when the 16-bit address is
+	 * used without enough dummy cycles and the opcode is using a different
+	 * buswidth than the address.
+	 */
+	if (op->addr.buswidth) {
+		switch (op->addr.nbytes) {
+		case 0:
+			break;
+		case 1:
+			ifr |= QSPI_IFR_OPTEN | QSPI_IFR_OPTL_8BIT;
+			icr |= QSPI_ICR_OPT(op->addr.val & 0xff);
+			break;
+		case 2:
+			if (dummy_cycles < 8 / op->addr.buswidth) {
+				ifr &= ~QSPI_IFR_INSTEN;
+				ifr |= QSPI_IFR_ADDREN;
+				iar = (op->cmd.opcode << 16) |
+					(op->addr.val & 0xffff);
+			} else {
+				ifr |= QSPI_IFR_ADDREN;
+				iar = (op->addr.val << 8) & 0xffffff;
+				dummy_cycles -= 8 / op->addr.buswidth;
+			}
+			break;
+		case 3:
+			ifr |= QSPI_IFR_ADDREN;
+			iar = op->addr.val & 0xffffff;
+			break;
+		case 4:
+			ifr |= QSPI_IFR_ADDREN | QSPI_IFR_ADDRL;
+			iar = op->addr.val & 0x7ffffff;
+			break;
+		default:
+			return -ENOTSUPP;
+		}
+	}
+
+	/* offset of the data access in the QSPI memory space */
+	*offset = iar;
+
+	/* Set number of dummy cycles */
+	if (dummy_cycles)
+		ifr |= QSPI_IFR_NBDUM(dummy_cycles);
+
+	/* Set data enable */
+	if (op->data.nbytes)
+		ifr |= QSPI_IFR_DATAEN;
+
+	/*
+	 * If the QSPI controller is set in regular SPI mode, set it in
+	 * Serial Memory Mode (SMM).
+	 */
+	if (aq->mr != QSPI_MR_SMM) {
+		writel(QSPI_MR_SMM, aq->regs + QSPI_MR);
+		aq->mr = QSPI_MR_SMM;
+	}
+
+	/* Clear pending interrupts */
+	(void)readl(aq->regs + QSPI_SR);
+
+	if (aq->caps->has_ricr) {
+		if (!op->addr.nbytes && op->data.dir == SPI_MEM_DATA_IN)
+			ifr |= QSPI_IFR_APBTFRTYP_READ;
+
+		/* Set QSPI Instruction Frame registers */
+		writel(iar, aq->regs + QSPI_IAR);
+		if (op->data.dir == SPI_MEM_DATA_IN)
+			writel(icr, aq->regs + QSPI_RICR);
+		else
+			writel(icr, aq->regs + QSPI_WICR);
+		writel(ifr, aq->regs + QSPI_IFR);
+	} else {
+		if (op->data.dir == SPI_MEM_DATA_OUT)
+			ifr |= QSPI_IFR_SAMA5D2_WRITE_TRSFR;
+
+		/* Set QSPI Instruction Frame registers */
+		writel(iar, aq->regs + QSPI_IAR);
+		writel(icr, aq->regs + QSPI_ICR);
+		writel(ifr, aq->regs + QSPI_IFR);
+	}
+
+	return 0;
+}
+
+static int atmel_qspi_exec_op(struct spi_slave *slave,
+			      const struct spi_mem_op *op)
+{
+	struct atmel_qspi *aq = dev_get_priv(slave->dev->parent);
+	u32 sr, imr, offset;
+	int err;
+
+	err = atmel_qspi_set_cfg(aq, op, &offset);
+	if (err)
+		return err;
+
+	/* Skip to the final steps if there is no data */
+	if (op->data.nbytes) {
+		/* Dummy read of QSPI_IFR to synchronize APB and AHB accesses */
+		(void)readl(aq->regs + QSPI_IFR);
+
+		/* Send/Receive data */
+		if (op->data.dir == SPI_MEM_DATA_IN)
+			memcpy_fromio(op->data.buf.in, aq->mem + offset,
+				      op->data.nbytes);
+		else
+			memcpy_toio(aq->mem + offset, op->data.buf.out,
+				    op->data.nbytes);
+
+		/* Release the chip-select */
+		writel(QSPI_CR_LASTXFER, aq->regs + QSPI_CR);
+	}
+
+	/* Poll INSTruction End and Chip Select Rise flags. */
+	imr = QSPI_SR_INSTRE | QSPI_SR_CSR;
+	return readl_poll_timeout(aq->regs + QSPI_SR, sr, (sr & imr) == imr,
+				  1000000);
+}
+
+static int atmel_qspi_set_speed(struct udevice *bus, uint hz)
+{
+	struct atmel_qspi *aq = dev_get_priv(bus);
+	u32 scr, scbr, mask, new_value;
+
+	/* Compute the QSPI baudrate */
+	scbr = DIV_ROUND_UP(aq->bus_clk_rate, hz);
+	if (scbr > 0)
+		scbr--;
+
+	new_value = QSPI_SCR_SCBR(scbr);
+	mask = QSPI_SCR_SCBR_MASK;
+
+	scr = readl(aq->regs + QSPI_SCR);
+	if ((scr & mask) == new_value)
+		return 0;
+
+	scr = (scr & ~mask) | new_value;
+	writel(scr, aq->regs + QSPI_SCR);
+
+	return 0;
+}
+
+static int atmel_qspi_set_mode(struct udevice *bus, uint mode)
+{
+	struct atmel_qspi *aq = dev_get_priv(bus);
+	u32 scr, mask, new_value = 0;
+
+	if (mode & SPI_CPOL)
+		new_value = QSPI_SCR_CPOL;
+	if (mode & SPI_CPHA)
+		new_value = QSPI_SCR_CPHA;
+
+	mask = QSPI_SCR_CPOL | QSPI_SCR_CPHA;
+
+	scr = readl(aq->regs + QSPI_SCR);
+	if ((scr & mask) == new_value)
+		return 0;
+
+	scr = (scr & ~mask) | new_value;
+	writel(scr, aq->regs + QSPI_SCR);
+
+	return 0;
+}
+
+static int atmel_qspi_enable_clk(struct udevice *dev)
+{
+	struct atmel_qspi *aq = dev_get_priv(dev);
+	struct clk pclk, qspick;
+	int ret;
+
+	ret = clk_get_by_name(dev, "pclk", &pclk);
+	if (ret)
+		ret = clk_get_by_index(dev, 0, &pclk);
+
+	if (ret) {
+		dev_err(dev, "Missing QSPI peripheral clock\n");
+		return ret;
+	}
+
+	ret = clk_enable(&pclk);
+	if (ret) {
+		dev_err(dev, "Failed to enable QSPI peripheral clock\n");
+		goto free_pclk;
+	}
+
+	if (aq->caps->has_qspick) {
+		/* Get the QSPI system clock */
+		ret = clk_get_by_name(dev, "qspick", &qspick);
+		if (ret) {
+			dev_err(dev, "Missing QSPI peripheral clock\n");
+			goto free_pclk;
+		}
+
+		ret = clk_enable(&qspick);
+		if (ret)
+			dev_err(dev, "Failed to enable QSPI system clock\n");
+		clk_free(&qspick);
+	}
+
+	aq->bus_clk_rate = clk_get_rate(&pclk);
+	if (!aq->bus_clk_rate)
+		ret = -EINVAL;
+
+free_pclk:
+	clk_free(&pclk);
+
+	return ret;
+}
+
+static void atmel_qspi_init(struct atmel_qspi *aq)
+{
+	/* Reset the QSPI controller */
+	writel(QSPI_CR_SWRST, aq->regs + QSPI_CR);
+
+	/* Set the QSPI controller by default in Serial Memory Mode */
+	writel(QSPI_MR_SMM, aq->regs + QSPI_MR);
+	aq->mr = QSPI_MR_SMM;
+
+	/* Enable the QSPI controller */
+	writel(QSPI_CR_QSPIEN, aq->regs + QSPI_CR);
+}
+
+static int atmel_qspi_probe(struct udevice *dev)
+{
+	struct atmel_qspi *aq = dev_get_priv(dev);
+	struct resource res;
+	int ret;
+
+	aq->caps = (struct atmel_qspi_caps *)dev_get_driver_data(dev);
+	if (!aq->caps) {
+		dev_err(dev, "Could not retrieve QSPI caps\n");
+		return -EINVAL;
+	};
+
+	/* Map the registers */
+	ret = dev_read_resource_byname(dev, "qspi_base", &res);
+	if (ret) {
+		dev_err(dev, "missing registers\n");
+		return ret;
+	}
+
+	aq->regs = devm_ioremap(dev, res.start, resource_size(&res));
+	if (IS_ERR(aq->regs))
+		return PTR_ERR(aq->regs);
+
+	/* Map the AHB memory */
+	ret = dev_read_resource_byname(dev, "qspi_mmap", &res);
+	if (ret) {
+		dev_err(dev, "missing AHB memory\n");
+		return ret;
+	}
+
+	aq->mem = devm_ioremap(dev, res.start, resource_size(&res));
+	if (IS_ERR(aq->mem))
+		return PTR_ERR(aq->mem);
+
+	ret = atmel_qspi_enable_clk(dev);
+	if (ret)
+		return ret;
+
+	atmel_qspi_init(aq);
+
+	return 0;
+}
+
+static const struct spi_controller_mem_ops atmel_qspi_mem_ops = {
+	.supports_op = atmel_qspi_supports_op,
+	.exec_op = atmel_qspi_exec_op,
+};
+
+static const struct dm_spi_ops atmel_qspi_ops = {
+	.set_speed = atmel_qspi_set_speed,
+	.set_mode = atmel_qspi_set_mode,
+	.mem_ops = &atmel_qspi_mem_ops,
+};
+
+static const struct atmel_qspi_caps atmel_sama5d2_qspi_caps = {};
+
+static const struct atmel_qspi_caps atmel_sam9x60_qspi_caps = {
+	.has_qspick = true,
+	.has_ricr = true,
+};
+
+static const struct udevice_id atmel_qspi_ids[] = {
+	{
+		.compatible = "atmel,sama5d2-qspi",
+		.data = (ulong)&atmel_sama5d2_qspi_caps,
+	},
+	{
+		.compatible = "microchip,sam9x60-qspi",
+		.data = (ulong)&atmel_sam9x60_qspi_caps,
+	},
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(atmel_qspi) = {
+	.name           = "atmel_qspi",
+	.id             = UCLASS_SPI,
+	.of_match       = atmel_qspi_ids,
+	.ops            = &atmel_qspi_ops,
+	.priv_auto_alloc_size = sizeof(struct atmel_qspi),
+	.probe          = atmel_qspi_probe,
+};