1 files changed, 74 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/i2c.c b/arch/arm/mach-omap2/i2c.c
new file mode 100644
index 0000000000..3b4b9514f4
--- /dev/null
+++ b/arch/arm/mach-omap2/i2c.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Helper module for board specific I2C bus registration
+ *
+ * Copyright (C) 2009 Nokia Corporation.
+ */
+
+#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 (soc_is_omap24xx() || soc_is_omap34xx() || soc_is_am35xx())
+		i2c_con = OMAP2_I2C_CON_OFFSET;
+	else
+		i2c_con = OMAP4_I2C_CON_OFFSET;
+
+	/* 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;
+}