spi: Add zynq spi controller driver

Zynq spi controller driver supports 2 buses and
3 chipselects on each bus.

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
Acked-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

2 files changed, 281 insertions, 0 deletions

diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 019132e..91d24ce 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -39,6 +39,7 @@ COBJS-$(CONFIG_TEGRA20_SFLASH) += tegra20_sflash.o
 COBJS-$(CONFIG_TEGRA20_SLINK) += tegra20_slink.o
 COBJS-$(CONFIG_TEGRA114_SPI) += tegra114_spi.o
 COBJS-$(CONFIG_XILINX_SPI) += xilinx_spi.o
+COBJS-$(CONFIG_ZYNQ_SPI) += zynq_spi.o
 
 COBJS	:= $(COBJS-y)
 SRCS	:= $(COBJS:.o=.c)
diff --git a/drivers/spi/zynq_spi.c b/drivers/spi/zynq_spi.c
new file mode 100644
index 0000000..5da8759
--- /dev/null
+++ b/drivers/spi/zynq_spi.c
@@ -0,0 +1,280 @@
+/*
+ * (C) Copyright 2013 Inc.
+ *
+ * Xilinx Zynq PS SPI controller driver (master mode only)
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <config.h>
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+#include <asm/io.h>
+#include <asm/arch/hardware.h>
+
+/* zynq spi register bit masks ZYNQ_SPI_<REG>_<BIT>_MASK */
+#define ZYNQ_SPI_CR_MSA_MASK		(1 << 15)	/* Manual start enb */
+#define ZYNQ_SPI_CR_MCS_MASK		(1 << 14)	/* Manual chip select */
+#define ZYNQ_SPI_CR_CS_MASK		(0xF << 10)	/* Chip select */
+#define ZYNQ_SPI_CR_BRD_MASK		(0x7 << 3)	/* Baud rate div */
+#define ZYNQ_SPI_CR_CPHA_MASK		(1 << 2)	/* Clock phase */
+#define ZYNQ_SPI_CR_CPOL_MASK		(1 << 1)	/* Clock polarity */
+#define ZYNQ_SPI_CR_MSTREN_MASK		(1 << 0)	/* Mode select */
+#define ZYNQ_SPI_IXR_RXNEMPTY_MASK	(1 << 4)	/* RX_FIFO_not_empty */
+#define ZYNQ_SPI_IXR_TXOW_MASK		(1 << 2)	/* TX_FIFO_not_full */
+#define ZYNQ_SPI_IXR_ALL_MASK		0x7F		/* All IXR bits */
+#define ZYNQ_SPI_ENR_SPI_EN_MASK	(1 << 0)	/* SPI Enable */
+
+#define ZYNQ_SPI_FIFO_DEPTH		128
+#ifndef CONFIG_SYS_ZYNQ_SPI_WAIT
+#define CONFIG_SYS_ZYNQ_SPI_WAIT	(CONFIG_SYS_HZ/100)	/* 10 ms */
+#endif
+
+/* zynq spi register set */
+struct zynq_spi_regs {
+	u32 cr;		/* 0x00 */
+	u32 isr;	/* 0x04 */
+	u32 ier;	/* 0x08 */
+	u32 idr;	/* 0x0C */
+	u32 imr;	/* 0x10 */
+	u32 enr;	/* 0x14 */
+	u32 dr;		/* 0x18 */
+	u32 txdr;	/* 0x1C */
+	u32 rxdr;	/* 0x20 */
+};
+
+/* zynq spi slave */
+struct zynq_spi_slave {
+	struct spi_slave slave;
+	struct zynq_spi_regs *base;
+	u8 mode;
+	u8 fifo_depth;
+	u32 speed_hz;
+	u32 input_hz;
+	u32 req_hz;
+};
+
+static inline struct zynq_spi_slave *to_zynq_spi_slave(struct spi_slave *slave)
+{
+	return container_of(slave, struct zynq_spi_slave, slave);
+}
+
+static inline struct zynq_spi_regs *get_zynq_spi_base(int dev)
+{
+	if (dev)
+		return (struct zynq_spi_regs *)ZYNQ_SPI_BASEADDR1;
+	else
+		return (struct zynq_spi_regs *)ZYNQ_SPI_BASEADDR0;
+}
+
+static void zynq_spi_init_hw(struct zynq_spi_slave *zslave)
+{
+	u32 confr;
+
+	/* Disable SPI */
+	writel(~ZYNQ_SPI_ENR_SPI_EN_MASK, &zslave->base->enr);
+
+	/* Disable Interrupts */
+	writel(ZYNQ_SPI_IXR_ALL_MASK, &zslave->base->idr);
+
+	/* Clear RX FIFO */
+	while (readl(&zslave->base->isr) &
+			ZYNQ_SPI_IXR_RXNEMPTY_MASK)
+		readl(&zslave->base->rxdr);
+
+	/* Clear Interrupts */
+	writel(ZYNQ_SPI_IXR_ALL_MASK, &zslave->base->isr);
+
+	/* Manual slave select and Auto start */
+	confr = ZYNQ_SPI_CR_MCS_MASK | ZYNQ_SPI_CR_CS_MASK |
+		ZYNQ_SPI_CR_MSTREN_MASK;
+	confr &= ~ZYNQ_SPI_CR_MSA_MASK;
+	writel(confr, &zslave->base->cr);
+
+	/* Enable SPI */
+	writel(ZYNQ_SPI_ENR_SPI_EN_MASK, &zslave->base->enr);
+}
+
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+	/* 2 bus with 3 chipselect */
+	return bus < 2 && cs < 3;
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+	struct zynq_spi_slave *zslave = to_zynq_spi_slave(slave);
+	u32 cr;
+
+	debug("spi_cs_activate: 0x%08x\n", (u32)slave);
+
+	clrbits_le32(&zslave->base->cr, ZYNQ_SPI_CR_CS_MASK);
+	cr = readl(&zslave->base->cr);
+	/*
+	 * CS cal logic: CS[13:10]
+	 * xxx0	- cs0
+	 * xx01	- cs1
+	 * x011 - cs2
+	 */
+	cr |= (~(0x1 << slave->cs) << 10) & ZYNQ_SPI_CR_CS_MASK;
+	writel(cr, &zslave->base->cr);
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+	struct zynq_spi_slave *zslave = to_zynq_spi_slave(slave);
+
+	debug("spi_cs_deactivate: 0x%08x\n", (u32)slave);
+
+	setbits_le32(&zslave->base->cr, ZYNQ_SPI_CR_CS_MASK);
+}
+
+void spi_init()
+{
+	/* nothing to do */
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+		unsigned int max_hz, unsigned int mode)
+{
+	struct zynq_spi_slave *zslave;
+
+	if (!spi_cs_is_valid(bus, cs))
+		return NULL;
+
+	zslave = spi_alloc_slave(struct zynq_spi_slave, bus, cs);
+	if (!zslave) {
+		printf("SPI_error: Fail to allocate zynq_spi_slave\n");
+		return NULL;
+	}
+
+	zslave->base = get_zynq_spi_base(bus);
+	zslave->mode = mode;
+	zslave->fifo_depth = ZYNQ_SPI_FIFO_DEPTH;
+	zslave->input_hz = 166666700;
+	zslave->speed_hz = zslave->input_hz / 2;
+	zslave->req_hz = max_hz;
+
+	/* init the zynq spi hw */
+	zynq_spi_init_hw(zslave);
+
+	return &zslave->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+	struct zynq_spi_slave *zslave = to_zynq_spi_slave(slave);
+
+	debug("spi_free_slave: 0x%08x\n", (u32)slave);
+	free(zslave);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+	struct zynq_spi_slave *zslave = to_zynq_spi_slave(slave);
+	u32 confr = 0;
+	u8 baud_rate_val = 0;
+
+	writel(~ZYNQ_SPI_ENR_SPI_EN_MASK, &zslave->base->enr);
+
+	/* Set the SPI Clock phase and polarities */
+	confr = readl(&zslave->base->cr);
+	confr &= ~(ZYNQ_SPI_CR_CPHA_MASK | ZYNQ_SPI_CR_CPOL_MASK);
+	if (zslave->mode & SPI_CPHA)
+		confr |= ZYNQ_SPI_CR_CPHA_MASK;
+	if (zslave->mode & SPI_CPOL)
+		confr |= ZYNQ_SPI_CR_CPOL_MASK;
+
+	/* Set the clock frequency */
+	if (zslave->req_hz == 0) {
+		/* Set baudrate x8, if the req_hz is 0 */
+		baud_rate_val = 0x2;
+	} else if (zslave->speed_hz != zslave->req_hz) {
+		while ((baud_rate_val < 8) &&
+				((zslave->input_hz /
+				(2 << baud_rate_val)) > zslave->req_hz))
+			baud_rate_val++;
+		zslave->speed_hz = zslave->req_hz / (2 << baud_rate_val);
+	}
+	confr &= ~ZYNQ_SPI_CR_BRD_MASK;
+	confr |= (baud_rate_val << 3);
+	writel(confr, &zslave->base->cr);
+
+	writel(ZYNQ_SPI_ENR_SPI_EN_MASK, &zslave->base->enr);
+
+	return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+	struct zynq_spi_slave *zslave = to_zynq_spi_slave(slave);
+
+	debug("spi_release_bus: 0x%08x\n", (u32)slave);
+	writel(~ZYNQ_SPI_ENR_SPI_EN_MASK, &zslave->base->enr);
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+		void *din, unsigned long flags)
+{
+	struct zynq_spi_slave *zslave = to_zynq_spi_slave(slave);
+	u32 len = bitlen / 8;
+	u32 tx_len = len, rx_len = len, tx_tvl;
+	const u8 *tx_buf = dout;
+	u8 *rx_buf = din, buf;
+	u32 ts, status;
+
+	debug("spi_xfer: bus:%i cs:%i bitlen:%i len:%i flags:%lx\n",
+	      slave->bus, slave->cs, bitlen, len, flags);
+
+	if (bitlen == 0)
+		return -1;
+
+	if (bitlen % 8) {
+		debug("spi_xfer: Non byte aligned SPI transfer\n");
+		return -1;
+	}
+
+	if (flags & SPI_XFER_BEGIN)
+		spi_cs_activate(slave);
+
+	while (rx_len > 0) {
+		/* Write the data into TX FIFO - tx threshold is fifo_depth */
+		tx_tvl = 0;
+		while ((tx_tvl < zslave->fifo_depth) && tx_len) {
+			if (tx_buf)
+				buf = *tx_buf++;
+			else
+				buf = 0;
+			writel(buf, &zslave->base->txdr);
+			tx_len--;
+			tx_tvl++;
+		}
+
+		/* Check TX FIFO completion */
+		ts = get_timer(0);
+		status = readl(&zslave->base->isr);
+		while (!(status & ZYNQ_SPI_IXR_TXOW_MASK)) {
+			if (get_timer(ts) > CONFIG_SYS_ZYNQ_SPI_WAIT) {
+				printf("spi_xfer: Timeout! TX FIFO not full\n");
+				return -1;
+			}
+			status = readl(&zslave->base->isr);
+		}
+
+		/* Read the data from RX FIFO */
+		status = readl(&zslave->base->isr);
+		while (status & ZYNQ_SPI_IXR_RXNEMPTY_MASK) {
+			buf = readl(&zslave->base->rxdr);
+			if (rx_buf)
+				*rx_buf++ = buf;
+			status = readl(&zslave->base->isr);
+			rx_len--;
+		}
+	}
+
+	if (flags & SPI_XFER_END)
+		spi_cs_deactivate(slave);
+
+	return 0;
+}