davinci: move i2c driver to drivers/i2c

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

1 files changed, 329 insertions, 0 deletions

diff --git a/drivers/i2c/davinci_i2c.c b/drivers/i2c/davinci_i2c.c
new file mode 100644
index 0000000000..eee1cbd25d
--- /dev/null
+++ b/drivers/i2c/davinci_i2c.c
@@ -0,0 +1,329 @@
+/*
+ * TI DaVinci (TMS320DM644x) I2C driver.
+ *
+ * Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net>
+ *
+ * --------------------------------------------------------
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/i2c_defs.h>
+
+#define CHECK_NACK() \
+	do {\
+		if (tmp & (I2C_TIMEOUT | I2C_STAT_NACK)) {\
+			REG(I2C_CON) = 0;\
+			return(1);\
+		}\
+	} while (0)
+
+
+static int wait_for_bus(void)
+{
+	int	stat, timeout;
+
+	REG(I2C_STAT) = 0xffff;
+
+	for (timeout = 0; timeout < 10; timeout++) {
+		if (!((stat = REG(I2C_STAT)) & I2C_STAT_BB)) {
+			REG(I2C_STAT) = 0xffff;
+			return(0);
+		}
+
+		REG(I2C_STAT) = stat;
+		udelay(50000);
+	}
+
+	REG(I2C_STAT) = 0xffff;
+	return(1);
+}
+
+
+static int poll_i2c_irq(int mask)
+{
+	int	stat, timeout;
+
+	for (timeout = 0; timeout < 10; timeout++) {
+		udelay(1000);
+		stat = REG(I2C_STAT);
+		if (stat & mask) {
+			return(stat);
+		}
+	}
+
+	REG(I2C_STAT) = 0xffff;
+	return(stat | I2C_TIMEOUT);
+}
+
+
+void flush_rx(void)
+{
+	int	dummy;
+
+	while (1) {
+		if (!(REG(I2C_STAT) & I2C_STAT_RRDY))
+			break;
+
+		dummy = REG(I2C_DRR);
+		REG(I2C_STAT) = I2C_STAT_RRDY;
+		udelay(1000);
+	}
+}
+
+
+void i2c_init(int speed, int slaveadd)
+{
+	u_int32_t	div, psc;
+
+	if (REG(I2C_CON) & I2C_CON_EN) {
+		REG(I2C_CON) = 0;
+		udelay (50000);
+	}
+
+	psc = 2;
+	div = (CONFIG_SYS_HZ_CLOCK / ((psc + 1) * speed)) - 10;	/* SCLL + SCLH */
+	REG(I2C_PSC) = psc;			/* 27MHz / (2 + 1) = 9MHz */
+	REG(I2C_SCLL) = (div * 50) / 100;	/* 50% Duty */
+	REG(I2C_SCLH) = div - REG(I2C_SCLL);
+
+	REG(I2C_OA) = slaveadd;
+	REG(I2C_CNT) = 0;
+
+	/* Interrupts must be enabled or I2C module won't work */
+	REG(I2C_IE) = I2C_IE_SCD_IE | I2C_IE_XRDY_IE |
+		I2C_IE_RRDY_IE | I2C_IE_ARDY_IE | I2C_IE_NACK_IE;
+
+	/* Now enable I2C controller (get it out of reset) */
+	REG(I2C_CON) = I2C_CON_EN;
+
+	udelay(1000);
+}
+
+
+int i2c_probe(u_int8_t chip)
+{
+	int	rc = 1;
+
+	if (chip == REG(I2C_OA)) {
+		return(rc);
+	}
+
+	REG(I2C_CON) = 0;
+	if (wait_for_bus()) {return(1);}
+
+	/* try to read one byte from current (or only) address */
+	REG(I2C_CNT) = 1;
+	REG(I2C_SA) = chip;
+	REG(I2C_CON) = (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP);
+	udelay (50000);
+
+	if (!(REG(I2C_STAT) & I2C_STAT_NACK)) {
+		rc = 0;
+		flush_rx();
+		REG(I2C_STAT) = 0xffff;
+	} else {
+		REG(I2C_STAT) = 0xffff;
+		REG(I2C_CON) |= I2C_CON_STP;
+		udelay(20000);
+		if (wait_for_bus()) {return(1);}
+	}
+
+	flush_rx();
+	REG(I2C_STAT) = 0xffff;
+	REG(I2C_CNT) = 0;
+	return(rc);
+}
+
+
+int i2c_read(u_int8_t chip, u_int32_t addr, int alen, u_int8_t *buf, int len)
+{
+	u_int32_t	tmp;
+	int		i;
+
+	if ((alen < 0) || (alen > 2)) {
+		printf("%s(): bogus address length %x\n", __FUNCTION__, alen);
+		return(1);
+	}
+
+	if (wait_for_bus()) {return(1);}
+
+	if (alen != 0) {
+		/* Start address phase */
+		tmp = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX;
+		REG(I2C_CNT) = alen;
+		REG(I2C_SA) = chip;
+		REG(I2C_CON) = tmp;
+
+		tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+		CHECK_NACK();
+
+		switch (alen) {
+			case 2:
+				/* Send address MSByte */
+				if (tmp & I2C_STAT_XRDY) {
+					REG(I2C_DXR) = (addr >> 8) & 0xff;
+				} else {
+					REG(I2C_CON) = 0;
+					return(1);
+				}
+
+				tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+				CHECK_NACK();
+				/* No break, fall through */
+			case 1:
+				/* Send address LSByte */
+				if (tmp & I2C_STAT_XRDY) {
+					REG(I2C_DXR) = addr & 0xff;
+				} else {
+					REG(I2C_CON) = 0;
+					return(1);
+				}
+
+				tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK | I2C_STAT_ARDY);
+
+				CHECK_NACK();
+
+				if (!(tmp & I2C_STAT_ARDY)) {
+					REG(I2C_CON) = 0;
+					return(1);
+				}
+		}
+	}
+
+	/* Address phase is over, now read 'len' bytes and stop */
+	tmp = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP;
+	REG(I2C_CNT) = len & 0xffff;
+	REG(I2C_SA) = chip;
+	REG(I2C_CON) = tmp;
+
+	for (i = 0; i < len; i++) {
+		tmp = poll_i2c_irq(I2C_STAT_RRDY | I2C_STAT_NACK | I2C_STAT_ROVR);
+
+		CHECK_NACK();
+
+		if (tmp & I2C_STAT_RRDY) {
+			buf[i] = REG(I2C_DRR);
+		} else {
+			REG(I2C_CON) = 0;
+			return(1);
+		}
+	}
+
+	tmp = poll_i2c_irq(I2C_STAT_SCD | I2C_STAT_NACK);
+
+	CHECK_NACK();
+
+	if (!(tmp & I2C_STAT_SCD)) {
+		REG(I2C_CON) = 0;
+		return(1);
+	}
+
+	flush_rx();
+	REG(I2C_STAT) = 0xffff;
+	REG(I2C_CNT) = 0;
+	REG(I2C_CON) = 0;
+
+	return(0);
+}
+
+
+int i2c_write(u_int8_t chip, u_int32_t addr, int alen, u_int8_t *buf, int len)
+{
+	u_int32_t	tmp;
+	int		i;
+
+	if ((alen < 0) || (alen > 2)) {
+		printf("%s(): bogus address length %x\n", __FUNCTION__, alen);
+		return(1);
+	}
+	if (len < 0) {
+		printf("%s(): bogus length %x\n", __FUNCTION__, len);
+		return(1);
+	}
+
+	if (wait_for_bus()) {return(1);}
+
+	/* Start address phase */
+	tmp = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX | I2C_CON_STP;
+	REG(I2C_CNT) = (alen == 0) ? len & 0xffff : (len & 0xffff) + alen;
+	REG(I2C_SA) = chip;
+	REG(I2C_CON) = tmp;
+
+	switch (alen) {
+		case 2:
+			/* Send address MSByte */
+			tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+			CHECK_NACK();
+
+			if (tmp & I2C_STAT_XRDY) {
+				REG(I2C_DXR) = (addr >> 8) & 0xff;
+			} else {
+				REG(I2C_CON) = 0;
+				return(1);
+			}
+			/* No break, fall through */
+		case 1:
+			/* Send address LSByte */
+			tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+			CHECK_NACK();
+
+			if (tmp & I2C_STAT_XRDY) {
+				REG(I2C_DXR) = addr & 0xff;
+			} else {
+				REG(I2C_CON) = 0;
+				return(1);
+			}
+	}
+
+	for (i = 0; i < len; i++) {
+		tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+		CHECK_NACK();
+
+		if (tmp & I2C_STAT_XRDY) {
+			REG(I2C_DXR) = buf[i];
+		} else {
+			return(1);
+		}
+	}
+
+	tmp = poll_i2c_irq(I2C_STAT_SCD | I2C_STAT_NACK);
+
+	CHECK_NACK();
+
+	if (!(tmp & I2C_STAT_SCD)) {
+		REG(I2C_CON) = 0;
+		return(1);
+	}
+
+	flush_rx();
+	REG(I2C_STAT) = 0xffff;
+	REG(I2C_CNT) = 0;
+	REG(I2C_CON) = 0;
+
+	return(0);
+}