spi: add TI QSPI driver

Adds a SPI master driver for the TI QSPI peripheral.
- Added quad read support.
- Added memory mapped support.

Signed-off-by: Matt Porter <matt.porter@linaro.org>
Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>

2 files changed, 312 insertions, 0 deletions

diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 91d24ce..e5941b0 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -38,6 +38,7 @@ COBJS-$(CONFIG_FDT_SPI) += fdt_spi.o
 COBJS-$(CONFIG_TEGRA20_SFLASH) += tegra20_sflash.o
 COBJS-$(CONFIG_TEGRA20_SLINK) += tegra20_slink.o
 COBJS-$(CONFIG_TEGRA114_SPI) += tegra114_spi.o
+COBJS-$(CONFIG_TI_QSPI) += ti_qspi.o
 COBJS-$(CONFIG_XILINX_SPI) += xilinx_spi.o
 COBJS-$(CONFIG_ZYNQ_SPI) += zynq_spi.o
 
diff --git a/drivers/spi/ti_qspi.c b/drivers/spi/ti_qspi.c
new file mode 100644
index 0000000..5a5b482
--- /dev/null
+++ b/drivers/spi/ti_qspi.c
@@ -0,0 +1,311 @@
+/*
+ * TI QSPI driver
+ *
+ * Copyright (C) 2013, Texas Instruments, Incorporated
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/omap.h>
+#include <malloc.h>
+#include <spi.h>
+
+/* ti qpsi register bit masks */
+#define QSPI_TIMEOUT                    2000000
+#define QSPI_FCLK                       192000000
+/* clock control */
+#define QSPI_CLK_EN                     (1 << 31)
+#define QSPI_CLK_DIV_MAX                0xffff
+/* command */
+#define QSPI_EN_CS(n)                   (n << 28)
+#define QSPI_WLEN(n)                    ((n-1) << 19)
+#define QSPI_3_PIN                      (1 << 18)
+#define QSPI_RD_SNGL                    (1 << 16)
+#define QSPI_WR_SNGL                    (2 << 16)
+#define QSPI_INVAL                      (4 << 16)
+#define QSPI_RD_QUAD                    (7 << 16)
+/* device control */
+#define QSPI_DD(m, n)                   (m << (3 + n*8))
+#define QSPI_CKPHA(n)                   (1 << (2 + n*8))
+#define QSPI_CSPOL(n)                   (1 << (1 + n*8))
+#define QSPI_CKPOL(n)                   (1 << (n*8))
+/* status */
+#define QSPI_WC                         (1 << 1)
+#define QSPI_BUSY                       (1 << 0)
+#define QSPI_WC_BUSY                    (QSPI_WC | QSPI_BUSY)
+#define QSPI_XFER_DONE                  QSPI_WC
+#define MM_SWITCH                       0x01
+#define MEM_CS                          0x100
+#define MEM_CS_UNSELECT                 0xfffff0ff
+#define MMAP_START_ADDR                 0x5c000000
+#define CORE_CTRL_IO                    0x4a002558
+
+#define QSPI_CMD_READ                   (0x3 << 0)
+#define QSPI_CMD_READ_QUAD              (0x6b << 0)
+#define QSPI_CMD_READ_FAST              (0x0b << 0)
+#define QSPI_SETUP0_NUM_A_BYTES         (0x2 << 8)
+#define QSPI_SETUP0_NUM_D_BYTES_NO_BITS (0x0 << 10)
+#define QSPI_SETUP0_NUM_D_BYTES_8_BITS  (0x1 << 10)
+#define QSPI_SETUP0_READ_NORMAL         (0x0 << 12)
+#define QSPI_SETUP0_READ_QUAD           (0x3 << 12)
+#define QSPI_CMD_WRITE                  (0x2 << 16)
+#define QSPI_NUM_DUMMY_BITS             (0x0 << 24)
+
+/* ti qspi register set */
+struct ti_qspi_regs {
+	u32 pid;
+	u32 pad0[3];
+	u32 sysconfig;
+	u32 pad1[3];
+	u32 int_stat_raw;
+	u32 int_stat_en;
+	u32 int_en_set;
+	u32 int_en_ctlr;
+	u32 intc_eoi;
+	u32 pad2[3];
+	u32 clk_ctrl;
+	u32 dc;
+	u32 cmd;
+	u32 status;
+	u32 data;
+	u32 setup0;
+	u32 setup1;
+	u32 setup2;
+	u32 setup3;
+	u32 memswitch;
+	u32 data1;
+	u32 data2;
+	u32 data3;
+};
+
+/* ti qspi slave */
+struct ti_qspi_slave {
+	struct spi_slave slave;
+	struct ti_qspi_regs *base;
+	unsigned int mode;
+	u32 cmd;
+	u32 dc;
+};
+
+static inline struct ti_qspi_slave *to_ti_qspi_slave(struct spi_slave *slave)
+{
+	return container_of(slave, struct ti_qspi_slave, slave);
+}
+
+static void ti_spi_setup_spi_register(struct ti_qspi_slave *qslave)
+{
+	struct spi_slave *slave = &qslave->slave;
+	u32 memval = 0;
+
+	slave->memory_map = (void *)MMAP_START_ADDR;
+
+	memval |= QSPI_CMD_READ | QSPI_SETUP0_NUM_A_BYTES |
+			QSPI_SETUP0_NUM_D_BYTES_NO_BITS |
+			QSPI_SETUP0_READ_NORMAL | QSPI_CMD_WRITE |
+			QSPI_NUM_DUMMY_BITS;
+
+	writel(memval, &qslave->base->setup0);
+}
+
+static void ti_spi_set_speed(struct spi_slave *slave, uint hz)
+{
+	struct ti_qspi_slave *qslave = to_ti_qspi_slave(slave);
+	uint clk_div;
+
+	debug("ti_spi_set_speed: hz: %d, clock divider %d\n", hz, clk_div);
+
+	if (!hz)
+		clk_div = 0;
+	else
+		clk_div = (QSPI_FCLK / hz) - 1;
+
+	/* disable SCLK */
+	writel(readl(&qslave->base->clk_ctrl) & ~QSPI_CLK_EN,
+	       &qslave->base->clk_ctrl);
+
+	/* assign clk_div values */
+	if (clk_div < 0)
+		clk_div = 0;
+	else if (clk_div > QSPI_CLK_DIV_MAX)
+		clk_div = QSPI_CLK_DIV_MAX;
+
+	/* enable SCLK */
+	writel(QSPI_CLK_EN | clk_div, &qslave->base->clk_ctrl);
+}
+
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+	return 1;
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+	/* CS handled in xfer */
+	return;
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+	struct ti_qspi_slave *qslave = to_ti_qspi_slave(slave);
+
+	debug("spi_cs_deactivate: 0x%08x\n", (u32)slave);
+
+	writel(qslave->cmd | QSPI_INVAL, &qslave->base->cmd);
+}
+
+void spi_init(void)
+{
+	/* nothing to do */
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+				  unsigned int max_hz, unsigned int mode)
+{
+	struct ti_qspi_slave *qslave;
+
+	qslave = spi_alloc_slave(struct ti_qspi_slave, bus, cs);
+	if (!qslave) {
+		printf("SPI_error: Fail to allocate ti_qspi_slave\n");
+		return NULL;
+	}
+
+	qslave->base = (struct ti_qspi_regs *)QSPI_BASE;
+	qslave->mode = mode;
+
+	ti_spi_set_speed(&qslave->slave, max_hz);
+
+#ifdef CONFIG_TI_SPI_MMAP
+	ti_spi_setup_spi_register(qslave);
+#endif
+
+	return &qslave->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+	struct ti_qspi_slave *qslave = to_ti_qspi_slave(slave);
+	free(qslave);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+	struct ti_qspi_slave *qslave = to_ti_qspi_slave(slave);
+
+	debug("spi_claim_bus: bus:%i cs:%i\n", slave->bus, slave->cs);
+
+	qslave->dc = 0;
+	if (qslave->mode & SPI_CPHA)
+		qslave->dc |= QSPI_CKPHA(slave->cs);
+	if (qslave->mode & SPI_CPOL)
+		qslave->dc |= QSPI_CKPOL(slave->cs);
+	if (qslave->mode & SPI_CS_HIGH)
+		qslave->dc |= QSPI_CSPOL(slave->cs);
+
+	writel(qslave->dc, &qslave->base->dc);
+	writel(0, &qslave->base->cmd);
+	writel(0, &qslave->base->data);
+
+	return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+	struct ti_qspi_slave *qslave = to_ti_qspi_slave(slave);
+
+	debug("spi_release_bus: bus:%i cs:%i\n", slave->bus, slave->cs);
+
+	writel(0, &qslave->base->dc);
+	writel(0, &qslave->base->cmd);
+	writel(0, &qslave->base->data);
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+	     void *din, unsigned long flags)
+{
+	struct ti_qspi_slave *qslave = to_ti_qspi_slave(slave);
+	uint words = bitlen >> 3; /* fixed 8-bit word length */
+	const uchar *txp = dout;
+	uchar *rxp = din;
+	uint status;
+	int timeout, val;
+
+	debug("spi_xfer: bus:%i cs:%i bitlen:%i words:%i flags:%lx\n",
+	      slave->bus, slave->cs, bitlen, words, flags);
+
+	/* Setup mmap flags */
+	if (flags & SPI_XFER_MMAP) {
+		writel(MM_SWITCH, &qslave->base->memswitch);
+		val = readl(CORE_CTRL_IO);
+		val |= MEM_CS;
+		writel(val, CORE_CTRL_IO);
+		return 0;
+	} else if (flags & SPI_XFER_MMAP_END) {
+		writel(~MM_SWITCH, &qslave->base->memswitch);
+		val = readl(CORE_CTRL_IO);
+		val &= MEM_CS_UNSELECT;
+		writel(val, CORE_CTRL_IO);
+		return 0;
+	}
+
+	if (bitlen == 0)
+		return -1;
+
+	if (bitlen % 8) {
+		debug("spi_xfer: Non byte aligned SPI transfer\n");
+		return -1;
+	}
+
+	/* Setup command reg */
+	qslave->cmd = 0;
+	qslave->cmd |= QSPI_WLEN(8);
+	qslave->cmd |= QSPI_EN_CS(slave->cs);
+	if (flags & SPI_3WIRE)
+		qslave->cmd |= QSPI_3_PIN;
+	qslave->cmd |= 0xfff;
+
+	while (words--) {
+		if (txp) {
+			debug("tx cmd %08x dc %08x data %02x\n",
+			      qslave->cmd | QSPI_WR_SNGL, qslave->dc, *txp);
+			writel(*txp++, &qslave->base->data);
+			writel(qslave->cmd | QSPI_WR_SNGL,
+			       &qslave->base->cmd);
+			status = readl(&qslave->base->status);
+			timeout = QSPI_TIMEOUT;
+			while ((status & QSPI_WC_BUSY) != QSPI_XFER_DONE) {
+				if (--timeout < 0) {
+					printf("spi_xfer: TX timeout!\n");
+					return -1;
+				}
+				status = readl(&qslave->base->status);
+			}
+			debug("tx done, status %08x\n", status);
+		}
+		if (rxp) {
+			qslave->cmd |= QSPI_RD_SNGL;
+			debug("rx cmd %08x dc %08x\n",
+			      qslave->cmd, qslave->dc);
+			writel(qslave->cmd, &qslave->base->cmd);
+			status = readl(&qslave->base->status);
+			timeout = QSPI_TIMEOUT;
+			while ((status & QSPI_WC_BUSY) != QSPI_XFER_DONE) {
+				if (--timeout < 0) {
+					printf("spi_xfer: RX timeout!\n");
+					return -1;
+				}
+				status = readl(&qslave->base->status);
+			}
+			*rxp++ = readl(&qslave->base->data);
+			debug("rx done, status %08x, read %02x\n",
+			      status, *(rxp-1));
+		}
+	}
+
+	/* Terminate frame */
+	if (flags & SPI_XFER_END)
+		spi_cs_deactivate(slave);
+
+	return 0;
+}