Tegra: T210: Add QSPI driver

This is the normal Tegra SPI driver modified to work with the
QSPI controller in Tegra210. It does not do 2x/4x transfers
or any other QSPI protocol.

Signed-off-by: Yen Lin <yelin@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Reviewed-by: Jagan Teki <jteki@openedev.com>

3 files changed, 425 insertions, 0 deletions

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 7d7a9d0809..a0dbd8b640 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -123,6 +123,13 @@ config TEGRA20_SLINK
 	  be used to access the SPI NOR flash on platforms embedding this
 	  nVidia Tegra20/Tegra30 IP cores.
 
+config TEGRA210_QSPI
+	bool "nVidia Tegra210 QSPI driver"
+	help
+	  Enable the Tegra Quad-SPI (QSPI) driver for T210. This driver
+	  be used to access SPI chips on platforms embedding this
+	  NVIDIA Tegra210 IP core.
+
 config XILINX_SPI
 	bool "Xilinx SPI driver"
 	help
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 637fea8544..3eca7456d6 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_SH_QSPI) += sh_qspi.o
 obj-$(CONFIG_TEGRA114_SPI) += tegra114_spi.o
 obj-$(CONFIG_TEGRA20_SFLASH) += tegra20_sflash.o
 obj-$(CONFIG_TEGRA20_SLINK) += tegra20_slink.o
+obj-$(CONFIG_TEGRA210_QSPI) += tegra210_qspi.o
 obj-$(CONFIG_TI_QSPI) += ti_qspi.o
 obj-$(CONFIG_XILINX_SPI) += xilinx_spi.o
 obj-$(CONFIG_ZYNQ_SPI) += zynq_spi.o
diff --git a/drivers/spi/tegra210_qspi.c b/drivers/spi/tegra210_qspi.c
new file mode 100644
index 0000000000..6bbbe93839
--- /dev/null
+++ b/drivers/spi/tegra210_qspi.c
@@ -0,0 +1,417 @@
+/*
+ * NVIDIA Tegra210 QSPI controller driver
+ *
+ * (C) Copyright 2015 NVIDIA Corporation <www.nvidia.com>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <asm/arch-tegra/clk_rst.h>
+#include <spi.h>
+#include <fdtdec.h>
+#include "tegra_spi.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* COMMAND1 */
+#define QSPI_CMD1_GO			BIT(31)
+#define QSPI_CMD1_M_S			BIT(30)
+#define QSPI_CMD1_MODE_MASK		GENMASK(1,0)
+#define QSPI_CMD1_MODE_SHIFT		28
+#define QSPI_CMD1_CS_SEL_MASK		GENMASK(1,0)
+#define QSPI_CMD1_CS_SEL_SHIFT		26
+#define QSPI_CMD1_CS_POL_INACTIVE0	BIT(22)
+#define QSPI_CMD1_CS_SW_HW		BIT(21)
+#define QSPI_CMD1_CS_SW_VAL		BIT(20)
+#define QSPI_CMD1_IDLE_SDA_MASK		GENMASK(1,0)
+#define QSPI_CMD1_IDLE_SDA_SHIFT	18
+#define QSPI_CMD1_BIDIR			BIT(17)
+#define QSPI_CMD1_LSBI_FE		BIT(16)
+#define QSPI_CMD1_LSBY_FE		BIT(15)
+#define QSPI_CMD1_BOTH_EN_BIT		BIT(14)
+#define QSPI_CMD1_BOTH_EN_BYTE		BIT(13)
+#define QSPI_CMD1_RX_EN			BIT(12)
+#define QSPI_CMD1_TX_EN			BIT(11)
+#define QSPI_CMD1_PACKED		BIT(5)
+#define QSPI_CMD1_BITLEN_MASK		GENMASK(4,0)
+#define QSPI_CMD1_BITLEN_SHIFT		0
+
+/* COMMAND2 */
+#define QSPI_CMD2_TX_CLK_TAP_DELAY	BIT(6)
+#define QSPI_CMD2_TX_CLK_TAP_DELAY_MASK	GENMASK(11,6)
+#define QSPI_CMD2_RX_CLK_TAP_DELAY	BIT(0)
+#define QSPI_CMD2_RX_CLK_TAP_DELAY_MASK	GENMASK(5,0)
+
+/* TRANSFER STATUS */
+#define QSPI_XFER_STS_RDY		BIT(30)
+
+/* FIFO STATUS */
+#define QSPI_FIFO_STS_CS_INACTIVE	BIT(31)
+#define QSPI_FIFO_STS_FRAME_END		BIT(30)
+#define QSPI_FIFO_STS_RX_FIFO_FLUSH	BIT(15)
+#define QSPI_FIFO_STS_TX_FIFO_FLUSH	BIT(14)
+#define QSPI_FIFO_STS_ERR		BIT(8)
+#define QSPI_FIFO_STS_TX_FIFO_OVF	BIT(7)
+#define QSPI_FIFO_STS_TX_FIFO_UNR	BIT(6)
+#define QSPI_FIFO_STS_RX_FIFO_OVF	BIT(5)
+#define QSPI_FIFO_STS_RX_FIFO_UNR	BIT(4)
+#define QSPI_FIFO_STS_TX_FIFO_FULL	BIT(3)
+#define QSPI_FIFO_STS_TX_FIFO_EMPTY	BIT(2)
+#define QSPI_FIFO_STS_RX_FIFO_FULL	BIT(1)
+#define QSPI_FIFO_STS_RX_FIFO_EMPTY	BIT(0)
+
+#define QSPI_TIMEOUT		1000
+
+struct qspi_regs {
+	u32 command1;	/* 000:QSPI_COMMAND1 register */
+	u32 command2;	/* 004:QSPI_COMMAND2 register */
+	u32 timing1;	/* 008:QSPI_CS_TIM1 register */
+	u32 timing2;	/* 00c:QSPI_CS_TIM2 register */
+	u32 xfer_status;/* 010:QSPI_TRANS_STATUS register */
+	u32 fifo_status;/* 014:QSPI_FIFO_STATUS register */
+	u32 tx_data;	/* 018:QSPI_TX_DATA register */
+	u32 rx_data;	/* 01c:QSPI_RX_DATA register */
+	u32 dma_ctl;	/* 020:QSPI_DMA_CTL register */
+	u32 dma_blk;	/* 024:QSPI_DMA_BLK register */
+	u32 rsvd[56];	/* 028-107 reserved */
+	u32 tx_fifo;	/* 108:QSPI_FIFO1 register */
+	u32 rsvd2[31];	/* 10c-187 reserved */
+	u32 rx_fifo;	/* 188:QSPI_FIFO2 register */
+	u32 spare_ctl;	/* 18c:QSPI_SPARE_CTRL register */
+};
+
+struct tegra210_qspi_priv {
+	struct qspi_regs *regs;
+	unsigned int freq;
+	unsigned int mode;
+	int periph_id;
+	int valid;
+	int last_transaction_us;
+};
+
+static int tegra210_qspi_ofdata_to_platdata(struct udevice *bus)
+{
+	struct tegra_spi_platdata *plat = bus->platdata;
+	const void *blob = gd->fdt_blob;
+	int node = bus->of_offset;
+
+	plat->base = dev_get_addr(bus);
+	plat->periph_id = clock_decode_periph_id(blob, node);
+
+	if (plat->periph_id == PERIPH_ID_NONE) {
+		debug("%s: could not decode periph id %d\n", __func__,
+		      plat->periph_id);
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	/* Use 500KHz as a suitable default */
+	plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
+					500000);
+	plat->deactivate_delay_us = fdtdec_get_int(blob, node,
+					"spi-deactivate-delay", 0);
+	debug("%s: base=%#08lx, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n",
+	      __func__, plat->base, plat->periph_id, plat->frequency,
+	      plat->deactivate_delay_us);
+
+	return 0;
+}
+
+static int tegra210_qspi_probe(struct udevice *bus)
+{
+	struct tegra_spi_platdata *plat = dev_get_platdata(bus);
+	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+
+	priv->regs = (struct qspi_regs *)plat->base;
+
+	priv->last_transaction_us = timer_get_us();
+	priv->freq = plat->frequency;
+	priv->periph_id = plat->periph_id;
+
+	return 0;
+}
+
+static int tegra210_qspi_claim_bus(struct udevice *bus)
+{
+	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+	struct qspi_regs *regs = priv->regs;
+
+	/* Change SPI clock to correct frequency, PLLP_OUT0 source */
+	clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH, priv->freq);
+
+	debug("%s: FIFO STATUS = %08x\n", __func__, readl(&regs->fifo_status));
+
+	/* Set master mode and sw controlled CS */
+	setbits_le32(&regs->command1, QSPI_CMD1_M_S | QSPI_CMD1_CS_SW_HW |
+		     (priv->mode << QSPI_CMD1_MODE_SHIFT));
+	debug("%s: COMMAND1 = %08x\n", __func__, readl(&regs->command1));
+
+	return 0;
+}
+
+/**
+ * Activate the CS by driving it LOW
+ *
+ * @param slave	Pointer to spi_slave to which controller has to
+ *		communicate with
+ */
+static void spi_cs_activate(struct udevice *dev)
+{
+	struct udevice *bus = dev->parent;
+	struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
+	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+
+	/* If it's too soon to do another transaction, wait */
+	if (pdata->deactivate_delay_us &&
+	    priv->last_transaction_us) {
+		ulong delay_us;		/* The delay completed so far */
+		delay_us = timer_get_us() - priv->last_transaction_us;
+		if (delay_us < pdata->deactivate_delay_us)
+			udelay(pdata->deactivate_delay_us - delay_us);
+	}
+
+	clrbits_le32(&priv->regs->command1, QSPI_CMD1_CS_SW_VAL);
+}
+
+/**
+ * Deactivate the CS by driving it HIGH
+ *
+ * @param slave	Pointer to spi_slave to which controller has to
+ *		communicate with
+ */
+static void spi_cs_deactivate(struct udevice *dev)
+{
+	struct udevice *bus = dev->parent;
+	struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
+	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+
+	setbits_le32(&priv->regs->command1, QSPI_CMD1_CS_SW_VAL);
+
+	/* Remember time of this transaction so we can honour the bus delay */
+	if (pdata->deactivate_delay_us)
+		priv->last_transaction_us = timer_get_us();
+
+	debug("Deactivate CS, bus '%s'\n", bus->name);
+}
+
+static int tegra210_qspi_xfer(struct udevice *dev, unsigned int bitlen,
+			     const void *data_out, void *data_in,
+			     unsigned long flags)
+{
+	struct udevice *bus = dev->parent;
+	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+	struct qspi_regs *regs = priv->regs;
+	u32 reg, tmpdout, tmpdin = 0;
+	const u8 *dout = data_out;
+	u8 *din = data_in;
+	int num_bytes, tm, ret;
+
+	debug("%s: slave %u:%u dout %p din %p bitlen %u\n",
+	      __func__, bus->seq, spi_chip_select(dev), dout, din, bitlen);
+	if (bitlen % 8)
+		return -1;
+	num_bytes = bitlen / 8;
+
+	ret = 0;
+
+	/* clear all error status bits */
+	reg = readl(&regs->fifo_status);
+	writel(reg, &regs->fifo_status);
+
+	/* flush RX/TX FIFOs */
+	setbits_le32(&regs->fifo_status,
+		     (QSPI_FIFO_STS_RX_FIFO_FLUSH |
+		      QSPI_FIFO_STS_TX_FIFO_FLUSH));
+
+	tm = QSPI_TIMEOUT;
+	while ((tm && readl(&regs->fifo_status) &
+		      (QSPI_FIFO_STS_RX_FIFO_FLUSH |
+		       QSPI_FIFO_STS_TX_FIFO_FLUSH))) {
+		tm--;
+		udelay(1);
+	}
+
+	if (!tm) {
+		printf("%s: timeout during QSPI FIFO flush!\n",
+		       __func__);
+		return -1;
+	}
+
+	/*
+	 * Notes:
+	 *   1. don't set LSBY_FE, so no need to swap bytes from/to TX/RX FIFOs;
+	 *   2. don't set RX_EN and TX_EN yet.
+	 *      (SW needs to make sure that while programming the blk_size,
+	 *       tx_en and rx_en bits must be zero)
+	 *      [TODO] I (Yen Lin) have problems when both RX/TX EN bits are set
+	 *	       i.e., both dout and din are not NULL.
+	 */
+	clrsetbits_le32(&regs->command1,
+			(QSPI_CMD1_LSBI_FE | QSPI_CMD1_LSBY_FE |
+			 QSPI_CMD1_RX_EN | QSPI_CMD1_TX_EN),
+			(spi_chip_select(dev) << QSPI_CMD1_CS_SEL_SHIFT));
+
+	/* set xfer size to 1 block (32 bits) */
+	writel(0, &regs->dma_blk);
+
+	if (flags & SPI_XFER_BEGIN)
+		spi_cs_activate(dev);
+
+	/* handle data in 32-bit chunks */
+	while (num_bytes > 0) {
+		int bytes;
+
+		tmpdout = 0;
+		bytes = (num_bytes > 4) ?  4 : num_bytes;
+
+		if (dout != NULL) {
+			memcpy((void *)&tmpdout, (void *)dout, bytes);
+			dout += bytes;
+			num_bytes -= bytes;
+			writel(tmpdout, &regs->tx_fifo);
+			setbits_le32(&regs->command1, QSPI_CMD1_TX_EN);
+		}
+
+		if (din != NULL)
+			setbits_le32(&regs->command1, QSPI_CMD1_RX_EN);
+
+		/* clear ready bit */
+		setbits_le32(&regs->xfer_status, QSPI_XFER_STS_RDY);
+
+		clrsetbits_le32(&regs->command1,
+				QSPI_CMD1_BITLEN_MASK << QSPI_CMD1_BITLEN_SHIFT,
+				(bytes * 8 - 1) << QSPI_CMD1_BITLEN_SHIFT);
+
+		/* Need to stabilize other reg bits before GO bit set.
+		 * As per the TRM:
+		 * "For successful operation at various freq combinations,
+		 * a minimum of 4-5 spi_clk cycle delay might be required
+		 * before enabling the PIO or DMA bits. The worst case delay
+		 * calculation can be done considering slowest qspi_clk as
+		 * 1MHz. Based on that 1us delay should be enough before
+		 * enabling PIO or DMA." Padded another 1us for safety.
+		 */
+		udelay(2);
+		setbits_le32(&regs->command1, QSPI_CMD1_GO);
+		udelay(1);
+
+		/*
+		 * Wait for SPI transmit FIFO to empty, or to time out.
+		 * The RX FIFO status will be read and cleared last
+		 */
+		for (tm = 0; tm < QSPI_TIMEOUT; ++tm) {
+			u32 fifo_status, xfer_status;
+
+			xfer_status = readl(&regs->xfer_status);
+			if (!(xfer_status & QSPI_XFER_STS_RDY))
+				continue;
+
+			fifo_status = readl(&regs->fifo_status);
+			if (fifo_status & QSPI_FIFO_STS_ERR) {
+				debug("%s: got a fifo error: ", __func__);
+				if (fifo_status & QSPI_FIFO_STS_TX_FIFO_OVF)
+					debug("tx FIFO overflow ");
+				if (fifo_status & QSPI_FIFO_STS_TX_FIFO_UNR)
+					debug("tx FIFO underrun ");
+				if (fifo_status & QSPI_FIFO_STS_RX_FIFO_OVF)
+					debug("rx FIFO overflow ");
+				if (fifo_status & QSPI_FIFO_STS_RX_FIFO_UNR)
+					debug("rx FIFO underrun ");
+				if (fifo_status & QSPI_FIFO_STS_TX_FIFO_FULL)
+					debug("tx FIFO full ");
+				if (fifo_status & QSPI_FIFO_STS_TX_FIFO_EMPTY)
+					debug("tx FIFO empty ");
+				if (fifo_status & QSPI_FIFO_STS_RX_FIFO_FULL)
+					debug("rx FIFO full ");
+				if (fifo_status & QSPI_FIFO_STS_RX_FIFO_EMPTY)
+					debug("rx FIFO empty ");
+				debug("\n");
+				break;
+			}
+
+			if (!(fifo_status & QSPI_FIFO_STS_RX_FIFO_EMPTY)) {
+				tmpdin = readl(&regs->rx_fifo);
+				if (din != NULL) {
+					memcpy(din, &tmpdin, bytes);
+					din += bytes;
+					num_bytes -= bytes;
+				}
+			}
+			break;
+		}
+
+		if (tm >= QSPI_TIMEOUT)
+			ret = tm;
+
+		/* clear ACK RDY, etc. bits */
+		writel(readl(&regs->fifo_status), &regs->fifo_status);
+	}
+
+	if (flags & SPI_XFER_END)
+		spi_cs_deactivate(dev);
+
+	debug("%s: transfer ended. Value=%08x, fifo_status = %08x\n",
+	      __func__, tmpdin, readl(&regs->fifo_status));
+
+	if (ret) {
+		printf("%s: timeout during SPI transfer, tm %d\n",
+		       __func__, ret);
+		return -1;
+	}
+
+	return ret;
+}
+
+static int tegra210_qspi_set_speed(struct udevice *bus, uint speed)
+{
+	struct tegra_spi_platdata *plat = bus->platdata;
+	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+
+	if (speed > plat->frequency)
+		speed = plat->frequency;
+	priv->freq = speed;
+	debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);
+
+	return 0;
+}
+
+static int tegra210_qspi_set_mode(struct udevice *bus, uint mode)
+{
+	struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+
+	priv->mode = mode;
+	debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
+
+	return 0;
+}
+
+static const struct dm_spi_ops tegra210_qspi_ops = {
+	.claim_bus	= tegra210_qspi_claim_bus,
+	.xfer		= tegra210_qspi_xfer,
+	.set_speed	= tegra210_qspi_set_speed,
+	.set_mode	= tegra210_qspi_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 tegra210_qspi_ids[] = {
+	{ .compatible = "nvidia,tegra210-qspi" },
+	{ }
+};
+
+U_BOOT_DRIVER(tegra210_qspi) = {
+	.name = "tegra210-qspi",
+	.id = UCLASS_SPI,
+	.of_match = tegra210_qspi_ids,
+	.ops = &tegra210_qspi_ops,
+	.ofdata_to_platdata = tegra210_qspi_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct tegra_spi_platdata),
+	.priv_auto_alloc_size = sizeof(struct tegra210_qspi_priv),
+	.per_child_auto_alloc_size = sizeof(struct spi_slave),
+	.probe = tegra210_qspi_probe,
+};