1 files changed, 93 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/i2c.c b/arch/arm/mach-omap2/i2c.c
new file mode 100644
index 000000000..37ff25ee3
--- /dev/null
+++ b/arch/arm/mach-omap2/i2c.c
@@ -0,0 +1,93 @@
+/*
+ * Helper module for board specific I2C bus registration
+ *
+ * Copyright (C) 2009 Nokia Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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 St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include "soc.h"
+#include "omap_hwmod.h"
+#include "omap_device.h"
+
+#include "prm.h"
+#include "common.h"
+#include "i2c.h"
+
+/* In register I2C_CON, Bit 15 is the I2C enable bit */
+#define I2C_EN					BIT(15)
+#define OMAP2_I2C_CON_OFFSET			0x24
+#define OMAP4_I2C_CON_OFFSET			0xA4
+
+#define MAX_OMAP_I2C_HWMOD_NAME_LEN	16
+
+/**
+ * omap_i2c_reset - reset the omap i2c module.
+ * @oh: struct omap_hwmod *
+ *
+ * The i2c moudle in omap2, omap3 had a special sequence to reset. The
+ * sequence is:
+ * - Disable the I2C.
+ * - Write to SOFTRESET bit.
+ * - Enable the I2C.
+ * - Poll on the RESETDONE bit.
+ * The sequence is implemented in below function. This is called for 2420,
+ * 2430 and omap3.
+ */
+int omap_i2c_reset(struct omap_hwmod *oh)
+{
+	u32 v;
+	u16 i2c_con;
+	int c = 0;
+
+	if (oh->class->rev == OMAP_I2C_IP_VERSION_2) {
+		i2c_con = OMAP4_I2C_CON_OFFSET;
+	} else if (oh->class->rev == OMAP_I2C_IP_VERSION_1) {
+		i2c_con = OMAP2_I2C_CON_OFFSET;
+	} else {
+		WARN(1, "Cannot reset I2C block %s: unsupported revision\n",
+		     oh->name);
+		return -EINVAL;
+	}
+
+	/* Disable I2C */
+	v = omap_hwmod_read(oh, i2c_con);
+	v &= ~I2C_EN;
+	omap_hwmod_write(v, oh, i2c_con);
+
+	/* Write to the SOFTRESET bit */
+	omap_hwmod_softreset(oh);
+
+	/* Enable I2C */
+	v = omap_hwmod_read(oh, i2c_con);
+	v |= I2C_EN;
+	omap_hwmod_write(v, oh, i2c_con);
+
+	/* Poll on RESETDONE bit */
+	omap_test_timeout((omap_hwmod_read(oh,
+				oh->class->sysc->syss_offs)
+				& SYSS_RESETDONE_MASK),
+				MAX_MODULE_SOFTRESET_WAIT, c);
+
+	if (c == MAX_MODULE_SOFTRESET_WAIT)
+		pr_warn("%s: %s: softreset failed (waited %d usec)\n",
+			__func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
+	else
+		pr_debug("%s: %s: softreset in %d usec\n", __func__,
+			oh->name, c);
+
+	return 0;
+}