[U-Boot] [PATCH v3] arm, i2c: added support for the TWSI I2C Interface

[Heiko Schocher <hs@denx.de>]

Signed-off-by: Heiko Schocher <hs@denx.de>
---
- changes since v1:
  added comments from Prafulla Wadaskar
- changes since v2
  added comments from Jean-Christophe
  - added speed setting

 drivers/i2c/Makefile       |    1 +
 drivers/i2c/kirkwood_i2c.c |  484 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 485 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/kirkwood_i2c.c

diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index ef32f13..4a12976 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -28,6 +28,7 @@ LIB	:= $(obj)libi2c.a
 COBJS-$(CONFIG_BFIN_TWI_I2C) += bfin-twi_i2c.o
 COBJS-$(CONFIG_DRIVER_DAVINCI_I2C) += davinci_i2c.o
 COBJS-$(CONFIG_FSL_I2C) += fsl_i2c.o
+COBJS-$(CONFIG_I2C_KIRKWOOD) += kirkwood_i2c.o
 COBJS-$(CONFIG_I2C_MXC) += mxc_i2c.o
 COBJS-$(CONFIG_DRIVER_OMAP1510_I2C) += omap1510_i2c.o
 COBJS-$(CONFIG_DRIVER_OMAP24XX_I2C) += omap24xx_i2c.o
diff --git a/drivers/i2c/kirkwood_i2c.c b/drivers/i2c/kirkwood_i2c.c
new file mode 100644
index 0000000..dd30499
--- /dev/null
+++ b/drivers/i2c/kirkwood_i2c.c
@@ -0,0 +1,484 @@
+/*
+ * Driver for the i2c controller on the Marvell line of host bridges
+ * (e.g, gt642[46]0, mv643[46]0, mv644[46]0, Orion SoC family),
+ * and Kirkwood family.
+ *
+ * Based on:
+ * Author: Mark A. Greer <mgreer@mvista.com>
+ *
+ * 2005 (c) MontaVista, Software, Inc.  This file is licensed under
+ * the terms of the GNU General Public License version 2.  This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ *
+ * ported from Linux to u-boot
+ * (C) Copyright 2009
+ * Heiko Schocher, DENX Software Engineering, hs at denx.de.
+ *
+ */
+#include <common.h>
+#include <i2c.h>
+#include <asm/arch/kirkwood.h>
+#include <asm/errno.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static unsigned int i2c_bus_num __attribute__ ((section (".data"))) = 0;
+#if defined(CONFIG_I2C_MUX)
+static unsigned int i2c_bus_num_mux __attribute__ ((section ("data"))) = 0;
+#endif
+
+/* Register defines */
+#define	KW_I2C_REG_SLAVE_ADDR			0x00
+#define	KW_I2C_REG_DATA				0x04
+#define	KW_I2C_REG_CONTROL			0x08
+#define	KW_I2C_REG_STATUS			0x0c
+#define	KW_I2C_REG_BAUD				0x0c
+#define	KW_I2C_REG_EXT_SLAVE_ADDR		0x10
+#define	KW_I2C_REG_SOFT_RESET			0x1c
+
+#define	KW_I2C_REG_CONTROL_ACK			0x00000004
+#define	KW_I2C_REG_CONTROL_IFLG			0x00000008
+#define	KW_I2C_REG_CONTROL_STOP			0x00000010
+#define	KW_I2C_REG_CONTROL_START		0x00000020
+#define	KW_I2C_REG_CONTROL_TWSIEN		0x00000040
+#define	KW_I2C_REG_CONTROL_INTEN		0x00000080
+
+/* Ctlr status values */
+#define	KW_I2C_STATUS_BUS_ERR			0x00
+#define	KW_I2C_STATUS_MAST_START		0x08
+#define	KW_I2C_STATUS_MAST_REPEAT_START		0x10
+#define	KW_I2C_STATUS_MAST_WR_ADDR_ACK		0x18
+#define	KW_I2C_STATUS_MAST_WR_ADDR_NO_ACK	0x20
+#define	KW_I2C_STATUS_MAST_WR_ACK		0x28
+#define	KW_I2C_STATUS_MAST_WR_NO_ACK		0x30
+#define	KW_I2C_STATUS_MAST_LOST_ARB		0x38
+#define	KW_I2C_STATUS_MAST_RD_ADDR_ACK		0x40
+#define	KW_I2C_STATUS_MAST_RD_ADDR_NO_ACK	0x48
+#define	KW_I2C_STATUS_MAST_RD_DATA_ACK		0x50
+#define	KW_I2C_STATUS_MAST_RD_DATA_NO_ACK	0x58
+#define	KW_I2C_STATUS_MAST_WR_ADDR_2_ACK	0xd0
+#define	KW_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK	0xd8
+#define	KW_I2C_STATUS_MAST_RD_ADDR_2_ACK	0xe0
+#define	KW_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK	0xe8
+#define	KW_I2C_STATUS_NO_STATUS			0xf8
+
+/* Driver states */
+enum {
+	KW_I2C_STATE_INVALID,
+	KW_I2C_STATE_IDLE,
+	KW_I2C_STATE_WAITING_FOR_START_COND,
+	KW_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
+	KW_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
+	KW_I2C_STATE_WAITING_FOR_SLAVE_ACK,
+	KW_I2C_STATE_WAITING_FOR_SLAVE_DATA,
+};
+
+/* Driver actions */
+enum {
+	KW_I2C_ACTION_INVALID,
+	KW_I2C_ACTION_CONTINUE,
+	KW_I2C_ACTION_SEND_START,
+	KW_I2C_ACTION_SEND_ADDR_1,
+	KW_I2C_ACTION_SEND_ADDR_2,
+	KW_I2C_ACTION_SEND_DATA,
+	KW_I2C_ACTION_RCV_DATA,
+	KW_I2C_ACTION_RCV_DATA_STOP,
+	KW_I2C_ACTION_SEND_STOP,
+};
+
+/* defines to get compatible with Linux driver */
+#define IRQ_NONE	0x0
+#define IRQ_HANDLED	0x01
+
+#define I2C_M_TEN	0x01
+#define I2C_M_RD	0x02
+#define	I2C_M_REV_DIR_ADDR	0x04;
+
+struct i2c_msg {
+	u32	addr;
+	u32	flags;
+	u8	*buf;
+	u32	len;
+};
+
+struct kirkwood_i2c_data {
+	int			irq;
+	u32			state;
+	u32			action;
+	u32			aborting;
+	u32			cntl_bits;
+	void			*reg_base;
+	u32			reg_base_p;
+	u32			reg_size;
+	u32			addr1;
+	u32			addr2;
+	u32			bytes_left;
+	u32			byte_posn;
+	u32			block;
+	int			rc;
+	u32			freq_m;
+	u32			freq_n;
+	struct i2c_msg		*msg;
+};
+
+static struct kirkwood_i2c_data __drv_data __attribute__ ((section (".data")));
+static struct kirkwood_i2c_data *drv_data = &__drv_data;
+static struct i2c_msg __i2c_msg __attribute__ ((section (".data")));
+static struct i2c_msg *kirkwood_i2c_msg = &__i2c_msg;
+
+/*
+ *****************************************************************************
+ *
+ *	Finite State Machine & Interrupt Routines
+ *
+ *****************************************************************************
+ */
+
+static inline int abs(int n)
+{
+	 if(n >= 0)
+		return n;
+	else
+		return n * -1;
+}
+
+static void kirkwood_calculate_speed(int speed)
+{
+	int	calcspeed;
+	int	diff;
+	int	best_diff = CONFIG_SYS_TCLK;
+	int	best_speed = 0;
+	int	m, n;
+	int	tmp[8] = {2, 4, 8, 16, 32, 64, 128, 256};
+
+	for (n = 0; n < 8; n++) {
+		for (m = 0; m < 16; m++) {
+			calcspeed = CONFIG_SYS_TCLK / (10 * (m + 1) * tmp[n]);
+			diff = abs((speed - calcspeed));
+			if ( diff < best_diff) {
+				best_diff = diff;
+				best_speed = calcspeed;
+				drv_data->freq_m = m;
+				drv_data->freq_n = n;
+			}
+		}
+	}
+}
+
+/* Reset hardware and initialize FSM */
+static void
+kirkwood_i2c_hw_init(int speed, int slaveadd)
+{
+	drv_data->state = KW_I2C_STATE_IDLE;
+
+	kirkwood_calculate_speed(speed);
+	writel(0, CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_SOFT_RESET);
+	writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)),
+		CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_BAUD);
+	writel(slaveadd, CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_SLAVE_ADDR);
+	writel(0, CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_EXT_SLAVE_ADDR);
+	writel(KW_I2C_REG_CONTROL_TWSIEN | KW_I2C_REG_CONTROL_STOP,
+		CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+}
+
+static void
+kirkwood_i2c_fsm(u32 status)
+{
+	/*
+	 * If state is idle, then this is likely the remnants of an old
+	 * operation that driver has given up on or the user has killed.
+	 * If so, issue the stop condition and go to idle.
+	 */
+	if (drv_data->state == KW_I2C_STATE_IDLE) {
+		drv_data->action = KW_I2C_ACTION_SEND_STOP;
+		return;
+	}
+
+	/* The status from the ctlr [mostly] tells us what to do next */
+	switch (status) {
+	/* Start condition interrupt */
+	case KW_I2C_STATUS_MAST_START: /* 0x08 */
+	case KW_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */
+		drv_data->action = KW_I2C_ACTION_SEND_ADDR_1;
+		drv_data->state = KW_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
+		break;
+
+	/* Performing a write */
+	case KW_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */
+		if (drv_data->msg->flags & I2C_M_TEN) {
+			drv_data->action = KW_I2C_ACTION_SEND_ADDR_2;
+			drv_data->state =
+				KW_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
+			break;
+		}
+		/* FALLTHRU */
+	case KW_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
+	case KW_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
+		if ((drv_data->bytes_left == 0)
+				|| (drv_data->aborting
+					&& (drv_data->byte_posn != 0))) {
+			drv_data->action = KW_I2C_ACTION_SEND_STOP;
+			drv_data->state = KW_I2C_STATE_IDLE;
+		} else {
+			drv_data->action = KW_I2C_ACTION_SEND_DATA;
+			drv_data->state =
+				KW_I2C_STATE_WAITING_FOR_SLAVE_ACK;
+			drv_data->bytes_left--;
+		}
+		break;
+
+	/* Performing a read */
+	case KW_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */
+		if (drv_data->msg->flags & I2C_M_TEN) {
+			drv_data->action = KW_I2C_ACTION_SEND_ADDR_2;
+			drv_data->state =
+				KW_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
+			break;
+		}
+		/* FALLTHRU */
+	case KW_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */
+		if (drv_data->bytes_left == 0) {
+			drv_data->action = KW_I2C_ACTION_SEND_STOP;
+			drv_data->state = KW_I2C_STATE_IDLE;
+			break;
+		}
+		/* FALLTHRU */
+	case KW_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */
+		if (status != KW_I2C_STATUS_MAST_RD_DATA_ACK)
+			drv_data->action = KW_I2C_ACTION_CONTINUE;
+		else {
+			drv_data->action = KW_I2C_ACTION_RCV_DATA;
+			drv_data->bytes_left--;
+		}
+		drv_data->state = KW_I2C_STATE_WAITING_FOR_SLAVE_DATA;
+
+		if ((drv_data->bytes_left == 1) || drv_data->aborting)
+			drv_data->cntl_bits &= ~KW_I2C_REG_CONTROL_ACK;
+		break;
+
+	case KW_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
+		drv_data->action = KW_I2C_ACTION_RCV_DATA_STOP;
+		drv_data->state = KW_I2C_STATE_IDLE;
+		break;
+
+	case KW_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */
+	case KW_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */
+	case KW_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */
+		/* Doesn't seem to be a device at other end */
+		drv_data->action = KW_I2C_ACTION_SEND_STOP;
+		drv_data->state = KW_I2C_STATE_IDLE;
+		drv_data->rc = -ENODEV;
+		break;
+
+	default:
+		printf("kirkwood_i2c_fsm: Ctlr Error -- state: 0x%x, "
+			"status: 0x%x, addr: 0x%x, flags: 0x%x\n",
+			 drv_data->state, status, drv_data->msg->addr,
+			 drv_data->msg->flags);
+		drv_data->action = KW_I2C_ACTION_SEND_STOP;
+		kirkwood_i2c_hw_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
+		drv_data->rc = -EIO;
+	}
+}
+
+static void
+kirkwood_i2c_do_action(void)
+{
+	switch(drv_data->action) {
+	case KW_I2C_ACTION_CONTINUE:
+		writel(drv_data->cntl_bits,
+			CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+		break;
+
+	case KW_I2C_ACTION_SEND_START:
+		writel(drv_data->cntl_bits | KW_I2C_REG_CONTROL_START,
+			CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+		break;
+
+	case KW_I2C_ACTION_SEND_ADDR_1:
+		writel(drv_data->addr1,
+			CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
+		writel(drv_data->cntl_bits,
+			CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+		break;
+
+	case KW_I2C_ACTION_SEND_ADDR_2:
+		writel(drv_data->addr2,
+			CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
+		writel(drv_data->cntl_bits,
+			CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+		break;
+
+	case KW_I2C_ACTION_SEND_DATA:
+		writel(drv_data->msg->buf[drv_data->byte_posn++],
+			CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
+		writel(drv_data->cntl_bits,
+			CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+		break;
+
+	case KW_I2C_ACTION_RCV_DATA:
+		drv_data->msg->buf[drv_data->byte_posn++] =
+			readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
+		writel(drv_data->cntl_bits,
+			CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+		break;
+
+	case KW_I2C_ACTION_RCV_DATA_STOP:
+		drv_data->msg->buf[drv_data->byte_posn++] =
+			readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
+		drv_data->cntl_bits &= ~KW_I2C_REG_CONTROL_INTEN;
+		writel(drv_data->cntl_bits | KW_I2C_REG_CONTROL_STOP,
+			CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+		drv_data->block = 0;
+		break;
+
+	case KW_I2C_ACTION_INVALID:
+	default:
+		printf("kirkwood_i2c_do_action: Invalid action: %d\n",
+			drv_data->action);
+		drv_data->rc = -EIO;
+		/* FALLTHRU */
+	case KW_I2C_ACTION_SEND_STOP:
+		drv_data->cntl_bits &= ~KW_I2C_REG_CONTROL_INTEN;
+		writel(drv_data->cntl_bits | KW_I2C_REG_CONTROL_STOP,
+			CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+		drv_data->block = 0;
+		break;
+	}
+}
+
+static	int
+kirkwood_i2c_intr(void)
+{
+	u32		status;
+	u32		ctrl;
+	int		rc = IRQ_NONE;
+
+	ctrl = readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+	while ((ctrl & KW_I2C_REG_CONTROL_IFLG) &&
+		(drv_data->rc == 0)) {
+		status = readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_STATUS);
+		kirkwood_i2c_fsm(status);
+		kirkwood_i2c_do_action();
+		rc = IRQ_HANDLED;
+		ctrl = readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+		udelay(1000);
+	}
+	return rc;
+}
+
+static void
+kirkwood_i2c_doio(struct i2c_msg *msg)
+{
+	int	ret;
+
+	while ((drv_data->rc == 0) && (drv_data->state != KW_I2C_STATE_IDLE)) {
+		/* poll Status register */
+		ret = kirkwood_i2c_intr();
+		if (ret == IRQ_NONE)
+			udelay(10);
+	}
+}
+
+static void
+kirkwood_i2c_prepare_for_io(struct i2c_msg *msg)
+{
+	u32	dir = 0;
+
+	drv_data->msg = msg;
+	drv_data->byte_posn = 0;
+	drv_data->bytes_left = msg->len;
+	drv_data->aborting = 0;
+	drv_data->rc = 0;
+	/* in u-boot we use no IRQs */
+	drv_data->cntl_bits = KW_I2C_REG_CONTROL_ACK | KW_I2C_REG_CONTROL_TWSIEN;
+
+	if (msg->flags & I2C_M_RD)
+		dir = 1;
+	if (msg->flags & I2C_M_TEN) {
+		drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
+		drv_data->addr2 = (u32)msg->addr & 0xff;
+	} else {
+		drv_data->addr1 = ((u32)msg->addr & 0x7f) << 1 | dir;
+		drv_data->addr2 = 0;
+	}
+	/* OK, no start it (from kirkwood_i2c_execute_msg())*/
+	drv_data->action = KW_I2C_ACTION_SEND_START;
+	drv_data->state = KW_I2C_STATE_WAITING_FOR_START_COND;
+	drv_data->block = 1;
+	kirkwood_i2c_do_action();
+}
+
+void
+i2c_init(int speed, int slaveadd)
+{
+	kirkwood_i2c_hw_init(speed, slaveadd);
+}
+
+int
+i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
+{
+	kirkwood_i2c_msg->buf = data;
+	kirkwood_i2c_msg->len = length;
+	kirkwood_i2c_msg->addr = dev;
+	kirkwood_i2c_msg->flags = I2C_M_RD;
+
+	kirkwood_i2c_prepare_for_io(kirkwood_i2c_msg);
+	kirkwood_i2c_doio(kirkwood_i2c_msg);
+	return drv_data->rc;
+}
+
+int
+i2c_write(u8 dev, uint addr, int alen, u8 *data, int length)
+{
+	kirkwood_i2c_msg->buf = data;
+	kirkwood_i2c_msg->len = length;
+	kirkwood_i2c_msg->addr = dev;
+	kirkwood_i2c_msg->flags = 0;
+
+	kirkwood_i2c_prepare_for_io(kirkwood_i2c_msg);
+	kirkwood_i2c_doio(kirkwood_i2c_msg);
+	return drv_data->rc;
+}
+
+int
+i2c_probe(uchar chip)
+{
+	return i2c_read(chip, 0, 0, NULL, 0);
+}
+
+int i2c_set_bus_num(unsigned int bus)
+{
+#if defined(CONFIG_I2C_MUX)
+	if (bus < CONFIG_SYS_MAX_I2C_BUS) {
+		i2c_bus_num = bus;
+	} else {
+		int	ret;
+
+		ret = i2x_mux_select_mux(bus);
+		if (ret)
+			return ret;
+		i2c_bus_num = 0;
+	}
+	i2c_bus_num_mux = bus;
+#else
+	if (bus > 0) {
+		return -1;
+	}
+
+	i2c_bus_num = bus;
+#endif
+	return 0;
+}
+
+unsigned int i2c_get_bus_num(void)
+{
+#if defined(CONFIG_I2C_MUX)
+	return i2c_bus_num_mux;
+#else
+	return i2c_bus_num;
+#endif
+}
+
-- 
1.6.0.GIT

-- 
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