[U-Boot] [PATCH 12/31] iMX28: Add I2C bus driver

[Marek Vasut <marek.vasut@gmail.com>]

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
---
 drivers/i2c/Makefile  |    1 +
 drivers/i2c/mxs_i2c.c |  243 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 244 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/mxs_i2c.c

diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index a48047a..2fb521e 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -31,6 +31,7 @@ COBJS-$(CONFIG_FSL_I2C) += fsl_i2c.o
 COBJS-$(CONFIG_I2C_MVTWSI) += mvtwsi.o
 COBJS-$(CONFIG_I2C_MV) += mv_i2c.o
 COBJS-$(CONFIG_I2C_MXC) += mxc_i2c.o
+COBJS-$(CONFIG_I2C_MXS) += mxs_i2c.o
 COBJS-$(CONFIG_DRIVER_OMAP1510_I2C) += omap1510_i2c.o
 COBJS-$(CONFIG_DRIVER_OMAP24XX_I2C) += omap24xx_i2c.o
 COBJS-$(CONFIG_DRIVER_OMAP34XX_I2C) += omap24xx_i2c.o
diff --git a/drivers/i2c/mxs_i2c.c b/drivers/i2c/mxs_i2c.c
new file mode 100644
index 0000000..cae50b1
--- /dev/null
+++ b/drivers/i2c/mxs_i2c.c
@@ -0,0 +1,243 @@
+/*
+ * Freescale i.MX28 I2C Driver
+ *
+ * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
+ * on behalf of DENX Software Engineering GmbH
+ *
+ * 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 <malloc.h>
+#include <asm/errno.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/regs-common.h>
+#include <asm/arch/regs-base.h>
+#include <asm/arch/regs-i2c.h>
+#include <asm/arch/mx28.h>
+
+#define	MXS_I2C_MAX_TIMEOUT	1000000
+
+void mxs_i2c_reset(void)
+{
+	struct mx28_i2c_regs *i2c_regs = (struct mx28_i2c_regs *)MXS_I2C0_BASE;
+	int ret;
+
+	ret = mx28_reset_block(&i2c_regs->hw_i2c_ctrl0_reg);
+	if (ret) {
+		debug("MXS I2C: Block reset timeout\n");
+		return;
+	}
+
+	writel(I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ | I2C_CTRL1_NO_SLAVE_ACK_IRQ |
+		I2C_CTRL1_EARLY_TERM_IRQ | I2C_CTRL1_MASTER_LOSS_IRQ |
+		I2C_CTRL1_SLAVE_STOP_IRQ | I2C_CTRL1_SLAVE_IRQ,
+		&i2c_regs->hw_i2c_ctrl1_clr);
+
+	writel(I2C_QUEUECTRL_PIO_QUEUE_MODE, &i2c_regs->hw_i2c_queuectrl_set);
+}
+
+void mxs_i2c_setup_read(uint8_t chip, int len)
+{
+	struct mx28_i2c_regs *i2c_regs = (struct mx28_i2c_regs *)MXS_I2C0_BASE;
+
+	writel(I2C_QUEUECMD_RETAIN_CLOCK | I2C_QUEUECMD_PRE_SEND_START |
+		I2C_QUEUECMD_MASTER_MODE | I2C_QUEUECMD_DIRECTION |
+		(1 << I2C_QUEUECMD_XFER_COUNT_OFFSET),
+		&i2c_regs->hw_i2c_queuecmd);
+
+	writel((chip << 1) | 1, &i2c_regs->hw_i2c_data);
+
+	writel(I2C_QUEUECMD_SEND_NAK_ON_LAST | I2C_QUEUECMD_MASTER_MODE |
+		(len << I2C_QUEUECMD_XFER_COUNT_OFFSET) |
+		I2C_QUEUECMD_POST_SEND_STOP, &i2c_regs->hw_i2c_queuecmd);
+
+	writel(I2C_QUEUECTRL_QUEUE_RUN, &i2c_regs->hw_i2c_queuectrl_set);
+}
+
+void mxs_i2c_write(uchar chip, uint addr, int alen,
+			uchar *buf, int blen, int stop)
+{
+	struct mx28_i2c_regs *i2c_regs = (struct mx28_i2c_regs *)MXS_I2C0_BASE;
+	uint32_t data;
+	int i, remain, off;
+
+	if ((alen > 4) || (alen == 0)) {
+		debug("MXS I2C: Invalid address length\n");
+		return;
+	}
+
+	if (stop)
+		stop = I2C_QUEUECMD_POST_SEND_STOP;
+
+	writel(I2C_QUEUECMD_PRE_SEND_START |
+		I2C_QUEUECMD_MASTER_MODE | I2C_QUEUECMD_DIRECTION |
+		((blen + alen + 1) << I2C_QUEUECMD_XFER_COUNT_OFFSET) | stop,
+		&i2c_regs->hw_i2c_queuecmd);
+
+	data = (chip << 1) << 24;
+
+	for (i = 0; i < alen; i++) {
+		data >>= 8;
+		data |= ((char *)&addr)[i] << 24;
+		if ((i & 3) == 2)
+			writel(data, &i2c_regs->hw_i2c_data);
+	}
+
+	off = i;
+	for (; i < off + blen; i++) {
+		data >>= 8;
+		data |= buf[i - off] << 24;
+		if ((i & 3) == 2)
+			writel(data, &i2c_regs->hw_i2c_data);
+	}
+
+	remain = 24 - ((i & 3) * 8);
+	if (remain)
+		writel(data >> remain, &i2c_regs->hw_i2c_data);
+
+	writel(I2C_QUEUECTRL_QUEUE_RUN, &i2c_regs->hw_i2c_queuectrl_set);
+}
+
+int mxs_i2c_wait_for_ack(void)
+{
+	struct mx28_i2c_regs *i2c_regs = (struct mx28_i2c_regs *)MXS_I2C0_BASE;
+	uint32_t tmp;
+	int timeout = MXS_I2C_MAX_TIMEOUT;
+
+	for (;;) {
+		tmp = readl(&i2c_regs->hw_i2c_ctrl1);
+		if (tmp & I2C_CTRL1_NO_SLAVE_ACK_IRQ) {
+			debug("MXS I2C: No slave ACK\n");
+			goto err;
+		}
+
+		if (tmp & (
+			I2C_CTRL1_EARLY_TERM_IRQ | I2C_CTRL1_MASTER_LOSS_IRQ |
+			I2C_CTRL1_SLAVE_STOP_IRQ | I2C_CTRL1_SLAVE_IRQ
+		)) {
+			debug("MXS I2C: Error (CTRL1 = %08x)\n", tmp);
+			goto err;
+		}
+
+		if (tmp & I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ)
+			break;
+
+		if (!timeout--) {
+			debug("MXS I2C: Operation timed out\n");
+			goto err;
+		}
+
+		udelay(1);
+	}
+
+	return 0;
+
+err:
+	mxs_i2c_reset();
+	return 1;
+}
+
+int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
+{
+	struct mx28_i2c_regs *i2c_regs = (struct mx28_i2c_regs *)MXS_I2C0_BASE;
+	uint32_t tmp = 0;
+	int ret;
+	int i;
+
+	mxs_i2c_write(chip, addr, alen, NULL, 0, 0);
+	ret = mxs_i2c_wait_for_ack();
+	if (ret) {
+		debug("MXS I2C: Failed writing address\n");
+		return ret;
+	}
+
+	mxs_i2c_setup_read(chip, len);
+	ret = mxs_i2c_wait_for_ack();
+	if (ret) {
+		debug("MXS I2C: Failed reading address\n");
+		return ret;
+	}
+
+	for (i = 0; i < len; i++) {
+		if (!(i & 3)) {
+			while (readl(&i2c_regs->hw_i2c_queuestat) &
+				I2C_QUEUESTAT_RD_QUEUE_EMPTY)
+				;
+			tmp = readl(&i2c_regs->hw_i2c_queuedata);
+		}
+		buffer[i] = tmp & 0xff;
+		tmp >>= 8;
+	}
+
+	return 0;
+}
+
+int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
+{
+	int ret;
+	mxs_i2c_write(chip, addr, alen, buffer, len, 1);
+	ret = mxs_i2c_wait_for_ack();
+	if (ret)
+		debug("MXS I2C: Failed writing address\n");
+
+	return ret;
+}
+
+int i2c_probe(uchar chip)
+{
+	int ret;
+	mxs_i2c_write(chip, 0, 1, NULL, 0, 1);
+	ret = mxs_i2c_wait_for_ack();
+	mxs_i2c_reset();
+	return ret;
+}
+
+void i2c_init(int speed, int slaveadd)
+{
+	struct mx28_i2c_regs *i2c_regs = (struct mx28_i2c_regs *)MXS_I2C0_BASE;
+
+	mxs_i2c_reset();
+
+	switch (speed) {
+	case 100000:
+		writel((0x0078 << I2C_TIMING0_HIGH_COUNT_OFFSET) |
+			(0x0030 << I2C_TIMING0_RCV_COUNT_OFFSET),
+			&i2c_regs->hw_i2c_timing0);
+		writel((0x0080 << I2C_TIMING1_LOW_COUNT_OFFSET) |
+			(0x0030 << I2C_TIMING1_XMIT_COUNT_OFFSET),
+			&i2c_regs->hw_i2c_timing1);
+		break;
+	case 400000:
+		writel((0x000f << I2C_TIMING0_HIGH_COUNT_OFFSET) |
+			(0x0007 << I2C_TIMING0_RCV_COUNT_OFFSET),
+			&i2c_regs->hw_i2c_timing0);
+		writel((0x001f << I2C_TIMING1_LOW_COUNT_OFFSET) |
+			(0x000f << I2C_TIMING1_XMIT_COUNT_OFFSET),
+			&i2c_regs->hw_i2c_timing1);
+		break;
+	default:
+		printf("MXS I2C: Invalid speed selected (%d Hz)\n", speed);
+		return;
+	}
+
+	writel((0x0015 << I2C_TIMING2_BUS_FREE_OFFSET) |
+		(0x000d << I2C_TIMING2_LEADIN_COUNT_OFFSET),
+		&i2c_regs->hw_i2c_timing2);
+
+	return;
+}
-- 
1.7.5.4