1 files changed, 140 insertions, 0 deletions
diff --git a/src/drivers/aspeed/common/ast_i2c.c b/src/drivers/aspeed/common/ast_i2c.c
new file mode 100644
index 0000000000..0838d10fcb
--- /dev/null
+++ b/src/drivers/aspeed/common/ast_i2c.c
@@ -0,0 +1,140 @@
+/*
+ * Copied from Linux drivers/gpu/drm/ast/ast_mode.c
+ *
+ * Copyright 2012 Red Hat Inc.
+ * Parts based on xf86-video-ast
+ * Copyright (c) 2005 ASPEED Technology Inc.
+ * Copyright Dave Airlie <airlied@redhat.com>
+ * Copyright 2019 9Elements Agency GmbH <patrick.rudolph@9elements.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ */
+
+#include <delay.h>
+#include <device/i2c_simple.h>
+
+#include "ast_drv.h"
+
+static struct ast_private *ast;
+
+#define _GET_INDEX_REG(x) ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, (x))
+#define ASPEED_BUS 0
+
+static int get_clock(unsigned int bus)
+{
+	uint32_t val, val2, count, pass;
+
+	count = 0;
+	pass = 0;
+	val = (_GET_INDEX_REG(0x10) >> 4) & 0x01;
+	do {
+		val2 = (_GET_INDEX_REG(0x10) >> 4) & 0x01;
+		if (val == val2) {
+			pass++;
+		} else {
+			pass = 0;
+			val = (_GET_INDEX_REG(0x10) >> 4) & 0x01;
+		}
+	} while ((pass < 5) && (count++ < 0x10000));
+
+	return val & 1 ? 1 : 0;
+}
+
+static int get_data(unsigned int bus)
+{
+	uint32_t val, val2, count, pass;
+
+	count = 0;
+	pass = 0;
+	val = (_GET_INDEX_REG(0x20) >> 5) & 0x01;
+	do {
+		val2 = (_GET_INDEX_REG(0x20) >> 5) & 0x01;
+		if (val == val2) {
+			pass++;
+		} else {
+			pass = 0;
+			val = (_GET_INDEX_REG(0x20) >> 5) & 0x01;
+		}
+	} while ((pass < 5) && (count++ < 0x10000));
+
+	return val & 1 ? 1 : 0;
+}
+
+static void set_clock(unsigned int bus, int clock)
+{
+	int i;
+	u8 ujcrb7, jtemp;
+
+	for (i = 0; i < 0x10000; i++) {
+		ujcrb7 = ((clock & 0x01) ? 0 : 1);
+		ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0xf4, ujcrb7);
+		jtemp = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x01);
+		if (ujcrb7 == jtemp)
+			break;
+	}
+}
+
+static void set_data(unsigned int bus, int data)
+{
+	int i;
+	u8 ujcrb7, jtemp;
+
+	for (i = 0; i < 0x10000; i++) {
+		ujcrb7 = ((data & 0x01) ? 0 : 1) << 2;
+		ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0xf1, ujcrb7);
+		jtemp = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x04);
+		if (ujcrb7 == jtemp)
+			break;
+	}
+}
+
+static struct software_i2c_ops ast_ops = {
+	.set_sda = set_data,
+	.set_scl = set_clock,
+	.get_sda = get_data,
+	.get_scl = get_clock,
+};
+
+int ast_software_i2c_read(struct ast_private *ast_priv, uint8_t edid[128])
+{
+	struct software_i2c_ops *backup;
+	int ret;
+
+	backup = software_i2c[ASPEED_BUS];
+
+	software_i2c[ASPEED_BUS] = &ast_ops;
+
+	ast = ast_priv;
+
+	/* Ast POST pulled SDA and SCL low, recover the bus to a known state */
+	set_clock(ASPEED_BUS, 1);
+	set_data(ASPEED_BUS, 1);
+
+	udelay(100);
+
+	/* Need to reset internal EEPROM counter to 0 */
+	ret = i2c_read_bytes(ASPEED_BUS, 0x50, 0, edid, 128);
+
+	software_i2c[ASPEED_BUS] = backup;
+
+	return ret;
+}