i2c: zynq: Add support for Xilinx Zynq

Support Xilinx Zynq i2c controller.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Tom Rini <trini@ti.com>

1 files changed, 306 insertions, 0 deletions

diff --git a/drivers/i2c/zynq_i2c.c b/drivers/i2c/zynq_i2c.c
new file mode 100644
index 0000000..ec49660
--- /dev/null
+++ b/drivers/i2c/zynq_i2c.c
@@ -0,0 +1,306 @@
+/*
+ * Driver for the Zynq-7000 PS I2C controller
+ * IP from Cadence (ID T-CS-PE-0007-100, Version R1p10f2)
+ *
+ * Author: Joe Hershberger <joe.hershberger@ni.com>
+ * Copyright (c) 2012 Joe Hershberger.
+ *
+ * Copyright (c) 2012-2013 Xilinx, Michal Simek
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <i2c.h>
+#include <asm/errno.h>
+#include <asm/arch/hardware.h>
+
+/* i2c register set */
+struct zynq_i2c_registers {
+	u32 control;
+	u32 status;
+	u32 address;
+	u32 data;
+	u32 interrupt_status;
+	u32 transfer_size;
+	u32 slave_mon_pause;
+	u32 time_out;
+	u32 interrupt_mask;
+	u32 interrupt_enable;
+	u32 interrupt_disable;
+};
+
+/* Control register fields */
+#define ZYNQ_I2C_CONTROL_RW		0x00000001
+#define ZYNQ_I2C_CONTROL_MS		0x00000002
+#define ZYNQ_I2C_CONTROL_NEA		0x00000004
+#define ZYNQ_I2C_CONTROL_ACKEN		0x00000008
+#define ZYNQ_I2C_CONTROL_HOLD		0x00000010
+#define ZYNQ_I2C_CONTROL_SLVMON		0x00000020
+#define ZYNQ_I2C_CONTROL_CLR_FIFO	0x00000040
+#define ZYNQ_I2C_CONTROL_DIV_B_SHIFT	8
+#define ZYNQ_I2C_CONTROL_DIV_B_MASK	0x00003F00
+#define ZYNQ_I2C_CONTROL_DIV_A_SHIFT	14
+#define ZYNQ_I2C_CONTROL_DIV_A_MASK	0x0000C000
+
+/* Status register values */
+#define ZYNQ_I2C_STATUS_RXDV	0x00000020
+#define ZYNQ_I2C_STATUS_TXDV	0x00000040
+#define ZYNQ_I2C_STATUS_RXOVF	0x00000080
+#define ZYNQ_I2C_STATUS_BA	0x00000100
+
+/* Interrupt register fields */
+#define ZYNQ_I2C_INTERRUPT_COMP		0x00000001
+#define ZYNQ_I2C_INTERRUPT_DATA		0x00000002
+#define ZYNQ_I2C_INTERRUPT_NACK		0x00000004
+#define ZYNQ_I2C_INTERRUPT_TO		0x00000008
+#define ZYNQ_I2C_INTERRUPT_SLVRDY	0x00000010
+#define ZYNQ_I2C_INTERRUPT_RXOVF	0x00000020
+#define ZYNQ_I2C_INTERRUPT_TXOVF	0x00000040
+#define ZYNQ_I2C_INTERRUPT_RXUNF	0x00000080
+#define ZYNQ_I2C_INTERRUPT_ARBLOST	0x00000200
+
+#define ZYNQ_I2C_FIFO_DEPTH		16
+#define ZYNQ_I2C_TRANSFERT_SIZE_MAX	255 /* Controller transfer limit */
+
+#if defined(CONFIG_ZYNQ_I2C0)
+# define ZYNQ_I2C_BASE	ZYNQ_I2C_BASEADDR0
+#else
+# define ZYNQ_I2C_BASE	ZYNQ_I2C_BASEADDR1
+#endif
+
+static struct zynq_i2c_registers *zynq_i2c =
+	(struct zynq_i2c_registers *)ZYNQ_I2C_BASE;
+
+/* I2C init called by cmd_i2c when doing 'i2c reset'. */
+void i2c_init(int requested_speed, int slaveadd)
+{
+	/* 111MHz / ( (3 * 17) * 22 ) = ~100KHz */
+	writel((16 << ZYNQ_I2C_CONTROL_DIV_B_SHIFT) |
+		(2 << ZYNQ_I2C_CONTROL_DIV_A_SHIFT), &zynq_i2c->control);
+
+	/* Enable master mode, ack, and 7-bit addressing */
+	setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_MS |
+		ZYNQ_I2C_CONTROL_ACKEN | ZYNQ_I2C_CONTROL_NEA);
+}
+
+#ifdef DEBUG
+static void zynq_i2c_debug_status(void)
+{
+	int int_status;
+	int status;
+	int_status = readl(&zynq_i2c->interrupt_status);
+
+	status = readl(&zynq_i2c->status);
+	if (int_status || status) {
+		debug("Status: ");
+		if (int_status & ZYNQ_I2C_INTERRUPT_COMP)
+			debug("COMP ");
+		if (int_status & ZYNQ_I2C_INTERRUPT_DATA)
+			debug("DATA ");
+		if (int_status & ZYNQ_I2C_INTERRUPT_NACK)
+			debug("NACK ");
+		if (int_status & ZYNQ_I2C_INTERRUPT_TO)
+			debug("TO ");
+		if (int_status & ZYNQ_I2C_INTERRUPT_SLVRDY)
+			debug("SLVRDY ");
+		if (int_status & ZYNQ_I2C_INTERRUPT_RXOVF)
+			debug("RXOVF ");
+		if (int_status & ZYNQ_I2C_INTERRUPT_TXOVF)
+			debug("TXOVF ");
+		if (int_status & ZYNQ_I2C_INTERRUPT_RXUNF)
+			debug("RXUNF ");
+		if (int_status & ZYNQ_I2C_INTERRUPT_ARBLOST)
+			debug("ARBLOST ");
+		if (status & ZYNQ_I2C_STATUS_RXDV)
+			debug("RXDV ");
+		if (status & ZYNQ_I2C_STATUS_TXDV)
+			debug("TXDV ");
+		if (status & ZYNQ_I2C_STATUS_RXOVF)
+			debug("RXOVF ");
+		if (status & ZYNQ_I2C_STATUS_BA)
+			debug("BA ");
+		debug("TS%d ", readl(&zynq_i2c->transfer_size));
+		debug("\n");
+	}
+}
+#endif
+
+/* Wait for an interrupt */
+static u32 zynq_i2c_wait(u32 mask)
+{
+	int timeout, int_status;
+
+	for (timeout = 0; timeout < 100; timeout++) {
+		udelay(100);
+		int_status = readl(&zynq_i2c->interrupt_status);
+		if (int_status & mask)
+			break;
+	}
+#ifdef DEBUG
+	zynq_i2c_debug_status();
+#endif
+	/* Clear interrupt status flags */
+	writel(int_status & mask, &zynq_i2c->interrupt_status);
+
+	return int_status & mask;
+}
+
+/*
+ * I2C probe called by cmd_i2c when doing 'i2c probe'.
+ * Begin read, nak data byte, end.
+ */
+int i2c_probe(u8 dev)
+{
+	/* Attempt to read a byte */
+	setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
+		ZYNQ_I2C_CONTROL_RW);
+	clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
+	writel(0xFF, &zynq_i2c->interrupt_status);
+	writel(dev, &zynq_i2c->address);
+	writel(1, &zynq_i2c->transfer_size);
+
+	return (zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP |
+		ZYNQ_I2C_INTERRUPT_NACK) &
+		ZYNQ_I2C_INTERRUPT_COMP) ? 0 : -ETIMEDOUT;
+}
+
+/*
+ * I2C read called by cmd_i2c when doing 'i2c read' and by cmd_eeprom.c
+ * Begin write, send address byte(s), begin read, receive data bytes, end.
+ */
+int i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
+{
+	u32 status;
+	u32 i = 0;
+	u8 *cur_data = data;
+
+	/* Check the hardware can handle the requested bytes */
+	if ((length < 0) || (length > ZYNQ_I2C_TRANSFERT_SIZE_MAX))
+		return -EINVAL;
+
+	/* Write the register address */
+	setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
+		ZYNQ_I2C_CONTROL_HOLD);
+	/*
+	 * Temporarily disable restart (by clearing hold)
+	 * It doesn't seem to work.
+	 */
+	clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_RW |
+		ZYNQ_I2C_CONTROL_HOLD);
+	writel(0xFF, &zynq_i2c->interrupt_status);
+	while (alen--)
+		writel(addr >> (8*alen), &zynq_i2c->data);
+	writel(dev, &zynq_i2c->address);
+
+	/* Wait for the address to be sent */
+	if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP)) {
+		/* Release the bus */
+		clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
+		return -ETIMEDOUT;
+	}
+	debug("Device acked address\n");
+
+	setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
+		ZYNQ_I2C_CONTROL_RW);
+	/* Start reading data */
+	writel(dev, &zynq_i2c->address);
+	writel(length, &zynq_i2c->transfer_size);
+
+	/* Wait for data */
+	do {
+		status = zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP |
+			ZYNQ_I2C_INTERRUPT_DATA);
+		if (!status) {
+			/* Release the bus */
+			clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
+			return -ETIMEDOUT;
+		}
+		debug("Read %d bytes\n",
+		      length - readl(&zynq_i2c->transfer_size));
+		for (; i < length - readl(&zynq_i2c->transfer_size); i++)
+			*(cur_data++) = readl(&zynq_i2c->data);
+	} while (readl(&zynq_i2c->transfer_size) != 0);
+	/* All done... release the bus */
+	clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
+
+#ifdef DEBUG
+	zynq_i2c_debug_status();
+#endif
+	return 0;
+}
+
+/*
+ * I2C write called by cmd_i2c when doing 'i2c write' and by cmd_eeprom.c
+ * Begin write, send address byte(s), send data bytes, end.
+ */
+int i2c_write(u8 dev, uint addr, int alen, u8 *data, int length)
+{
+	u8 *cur_data = data;
+
+	/* Write the register address */
+	setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
+		ZYNQ_I2C_CONTROL_HOLD);
+	clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_RW);
+	writel(0xFF, &zynq_i2c->interrupt_status);
+	while (alen--)
+		writel(addr >> (8*alen), &zynq_i2c->data);
+	/* Start the tranfer */
+	writel(dev, &zynq_i2c->address);
+	if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP)) {
+		/* Release the bus */
+		clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
+		return -ETIMEDOUT;
+	}
+
+	debug("Device acked address\n");
+	while (length--) {
+		writel(*(cur_data++), &zynq_i2c->data);
+		if (readl(&zynq_i2c->transfer_size) == ZYNQ_I2C_FIFO_DEPTH) {
+			if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP)) {
+				/* Release the bus */
+				clrbits_le32(&zynq_i2c->control,
+					     ZYNQ_I2C_CONTROL_HOLD);
+				return -ETIMEDOUT;
+			}
+		}
+	}
+
+	/* All done... release the bus */
+	clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
+	/* Wait for the address and data to be sent */
+	if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP))
+		return -ETIMEDOUT;
+	return 0;
+}
+
+int i2c_set_bus_num(unsigned int bus)
+{
+	/* Only support bus 0 */
+	if (bus > 0)
+		return -1;
+	return 0;
+}
+
+unsigned int i2c_get_bus_num(void)
+{
+	/* Only support bus 0 */
+	return 0;
+}