i2c: add generic read/modify/write operations

i2c_update is used to set or clear a mask
i2c_field_update is used to clear out a field before the set

Conflicts:
	common/i2c_master.c: i2c_read_offset16 not yet introduced.
	include/i2c.h : i2c_info_t not yet introduced.
BUG=none
BRANCH=none
TEST=make buildall -j

Change-Id: I7f8f93f4894fb9635092931a93961d328eacfeb9
Signed-off-by: Denis Brockus <dbrockus@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1956437
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-by: Jett Rink <jettrink@chromium.org>
Commit-Queue: Jett Rink <jettrink@chromium.org>
(cherry picked from commit d3129132f6e05cbce0141b5549272731bafb034f)
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3128751
Reviewed-by: JuHyun Kim <jkim@invensense.com>
Reviewed-by: Zhuohao Lee <zhuohao@chromium.org>
Tested-by: JuHyun Kim <jkim@invensense.com>
Commit-Queue: Zhuohao Lee <zhuohao@chromium.org>

1 files changed, 86 insertions, 0 deletions

diff --git a/common/i2c_master.c b/common/i2c_master.c
index ec2cad96df..df9dbe57c2 100644
--- a/common/i2c_master.c
+++ b/common/i2c_master.c
@@ -304,6 +304,92 @@ int i2c_write8(int port, int slave_addr, int offset, int data)
 	return i2c_xfer(port, slave_addr, buf, 2, 0, 0);
 }
 
+int i2c_update8(const int port,
+		const uint16_t slave_addr_flags,
+		const int offset,
+		const uint8_t mask,
+		const enum mask_update_action action)
+{
+	int rv;
+	int val, oldval;
+
+	rv = i2c_read8(port, slave_addr_flags, offset, &oldval);
+	if (rv)
+		return rv;
+
+	val = (action == MASK_SET) ? oldval | mask
+				   : oldval & ~mask;
+
+	if (val != oldval)
+		return i2c_write8(port, slave_addr_flags, offset, val);
+
+	return EC_SUCCESS;
+}
+
+int i2c_update16(const int port,
+		 const uint16_t slave_addr_flags,
+		 const int offset,
+		 const uint16_t mask,
+		 const enum mask_update_action action)
+{
+	int rv;
+	int val, oldval;
+
+	rv = i2c_read16(port, slave_addr_flags, offset, &oldval);
+	if (rv)
+		return rv;
+
+	val = (action == MASK_SET) ? oldval | mask
+				   : oldval & ~mask;
+
+	if (val != oldval)
+		return i2c_write16(port, slave_addr_flags, offset, val);
+
+	return EC_SUCCESS;
+}
+
+int i2c_field_update8(const int port,
+		      const uint16_t slave_addr_flags,
+		      const int offset,
+		      const uint8_t field_mask,
+		      const uint8_t set_value)
+{
+	int rv;
+	int val, oldval;
+
+	rv = i2c_read8(port, slave_addr_flags, offset, &oldval);
+	if (rv)
+		return rv;
+
+	val = (oldval & (~field_mask)) | set_value;
+
+	if (val != oldval)
+		return i2c_write8(port, slave_addr_flags, offset, val);
+
+	return EC_SUCCESS;
+}
+
+int i2c_field_update16(const int port,
+		       const uint16_t slave_addr_flags,
+		       const int offset,
+		       const uint16_t field_mask,
+		       const uint16_t set_value)
+{
+	int rv;
+	int val, oldval;
+
+	rv = i2c_read16(port, slave_addr_flags, offset, &oldval);
+	if (rv)
+		return rv;
+
+	val = (oldval & (~field_mask)) | set_value;
+
+	if (val != oldval)
+		return i2c_write16(port, slave_addr_flags, offset, val);
+
+	return EC_SUCCESS;
+}
+
 int i2c_read_string(int port, int slave_addr, int offset, uint8_t *data,
 		    int len)
 {