common: Add i2c 32bit read/write

Add functions and associated test to read/write a 32 bit register

BRANCH=smaug
TEST=Test on smaug with bm160 driver
BUG=chromium:39900

Change-Id: Ieff24b65f1eb8610874fe13c4a8fadf583a218cb
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/277535
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

7 files changed, 130 insertions, 4 deletions

diff --git a/chip/host/i2c.c b/chip/host/i2c.c
index 1ce7da9340..ebf3894a43 100644
--- a/chip/host/i2c.c
+++ b/chip/host/i2c.c
@@ -75,6 +75,36 @@ static int test_check_detached(int port, int slave_addr)
 	return 0;
 }
 
+int i2c_read32(int port, int slave_addr, int offset, int *data)
+{
+	const struct test_i2c_read_dev *p;
+	int rv;
+
+	if (test_check_detached(port, slave_addr))
+		return EC_ERROR_UNKNOWN;
+	for (p = __test_i2c_read32; p < __test_i2c_read32_end; ++p) {
+		rv = p->routine(port, slave_addr, offset, data);
+		if (rv != EC_ERROR_INVAL)
+			return rv;
+	}
+	return EC_ERROR_UNKNOWN;
+}
+
+int i2c_write32(int port, int slave_addr, int offset, int data)
+{
+	const struct test_i2c_write_dev *p;
+	int rv;
+
+	if (test_check_detached(port, slave_addr))
+		return EC_ERROR_UNKNOWN;
+	for (p = __test_i2c_write32; p < __test_i2c_write32_end; ++p) {
+		rv = p->routine(port, slave_addr, offset, data);
+		if (rv != EC_ERROR_INVAL)
+			return rv;
+	}
+	return EC_ERROR_UNKNOWN;
+}
+
 int i2c_read16(int port, int slave_addr, int offset, int *data)
 {
 	const struct test_i2c_read_dev *p;
diff --git a/common/i2c.c b/common/i2c.c
index 4a851da39d..518bca0647 100644
--- a/common/i2c.c
+++ b/common/i2c.c
@@ -77,15 +77,68 @@ void i2c_prepare_sysjump(void)
 		i2c_lock(i2c_ports[i].port, 1);
 }
 
+int i2c_read32(int port, int slave_addr, int offset, int *data)
+{
+	int rv;
+	uint8_t reg, buf[sizeof(uint32_t)];
+
+	reg = offset & 0xff;
+	/* I2C read 32-bit word: transmit 8-bit offset, and read 32bits */
+	i2c_lock(port, 1);
+	rv = i2c_xfer(port, slave_addr, &reg, 1, buf, sizeof(uint32_t),
+		      I2C_XFER_SINGLE);
+	i2c_lock(port, 0);
+
+	if (rv)
+		return rv;
+
+	if (slave_addr & I2C_FLAG_BIG_ENDIAN)
+		*data = ((int)buf[0] << 24) | ((int)buf[1] << 16) |
+			((int)buf[0] << 8) | buf[1];
+	else
+		*data = ((int)buf[3] << 24) | ((int)buf[2] << 16) |
+			((int)buf[1] << 8) | buf[0];
+
+	return EC_SUCCESS;
+}
+
+int i2c_write32(int port, int slave_addr, int offset, int data)
+{
+	int rv;
+	uint8_t buf[1 + sizeof(uint32_t)];
+
+	buf[0] = offset & 0xff;
+
+	if (slave_addr & I2C_FLAG_BIG_ENDIAN) {
+		buf[1] = (data >> 24) & 0xff;
+		buf[2] = (data >> 16) & 0xff;
+		buf[3] = (data >> 8) & 0xff;
+		buf[4] = data & 0xff;
+	} else {
+		buf[1] = data & 0xff;
+		buf[2] = (data >> 8) & 0xff;
+		buf[3] = (data >> 16) & 0xff;
+		buf[4] = (data >> 24) & 0xff;
+	}
+
+	i2c_lock(port, 1);
+	rv = i2c_xfer(port, slave_addr, buf, sizeof(uint32_t) + 1, NULL, 0,
+		      I2C_XFER_SINGLE);
+	i2c_lock(port, 0);
+
+	return rv;
+}
+
 int i2c_read16(int port, int slave_addr, int offset, int *data)
 {
 	int rv;
-	uint8_t reg, buf[2];
+	uint8_t reg, buf[sizeof(uint16_t)];
 
 	reg = offset & 0xff;
 	/* I2C read 16-bit word: transmit 8-bit offset, and read 16bits */
 	i2c_lock(port, 1);
-	rv = i2c_xfer(port, slave_addr, &reg, 1, buf, 2, I2C_XFER_SINGLE);
+	rv = i2c_xfer(port, slave_addr, &reg, 1, buf, sizeof(uint16_t),
+		      I2C_XFER_SINGLE);
 	i2c_lock(port, 0);
 
 	if (rv)
@@ -102,7 +155,7 @@ int i2c_read16(int port, int slave_addr, int offset, int *data)
 int i2c_write16(int port, int slave_addr, int offset, int data)
 {
 	int rv;
-	uint8_t buf[3];
+	uint8_t buf[1 + sizeof(uint16_t)];
 
 	buf[0] = offset & 0xff;
 
@@ -115,7 +168,8 @@ int i2c_write16(int port, int slave_addr, int offset, int data)
 	}
 
 	i2c_lock(port, 1);
-	rv = i2c_xfer(port, slave_addr, buf, 3, NULL, 0, I2C_XFER_SINGLE);
+	rv = i2c_xfer(port, slave_addr, buf, 1 + sizeof(uint16_t), NULL, 0,
+		      I2C_XFER_SINGLE);
 	i2c_lock(port, 0);
 
 	return rv;
diff --git a/core/host/host_exe.lds b/core/host/host_exe.lds
index e61b2d1c48..a30ebb4219 100644
--- a/core/host/host_exe.lds
+++ b/core/host/host_exe.lds
@@ -104,6 +104,14 @@ SECTIONS {
     *(.rodata.test_i2c.write16)
     __test_i2c_write16_end = .;
 
+    __test_i2c_read32 = .;
+    *(.rodata.test_i2c.read32)
+    __test_i2c_read32_end = .;
+
+    __test_i2c_write32 = .;
+    *(.rodata.test_i2c.write32)
+    __test_i2c_write32_end = .;
+
     __test_i2c_read_string = .;
     *(.rodata.test_i2c.read_string)
     __test_i2c_read_string_end = .;
diff --git a/include/i2c.h b/include/i2c.h
index dbc51eebbd..674dd84e80 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -162,6 +162,18 @@ void i2c_prepare_sysjump(void);
 void i2c_set_timeout(int port, uint32_t timeout);
 
 /**
+ * Read a 32-bit register from the slave at 8-bit slave address <slaveaddr>, at
+ * the specified 8-bit <offset> in the slave's address space.
+ */
+int i2c_read32(int port, int slave_addr, int offset, int *data);
+
+/**
+ * Write a 32-bit register to the slave at 8-bit slave address <slaveaddr>, at
+ * the specified 8-bit <offset> in the slave's address space.
+ */
+int i2c_write32(int port, int slave_addr, int offset, int data);
+
+/**
  * Read a 16-bit register from the slave at 8-bit slave address <slaveaddr>, at
  * the specified 8-bit <offset> in the slave's address space.
  */
diff --git a/include/link_defs.h b/include/link_defs.h
index 92783eb946..8c775affa2 100644
--- a/include/link_defs.h
+++ b/include/link_defs.h
@@ -64,8 +64,12 @@ extern const struct test_i2c_write_dev __test_i2c_write8[];
 extern const struct test_i2c_write_dev __test_i2c_write8_end[];
 extern const struct test_i2c_read_dev __test_i2c_read16[];
 extern const struct test_i2c_read_dev __test_i2c_read16_end[];
+extern const struct test_i2c_read_dev __test_i2c_read32[];
+extern const struct test_i2c_read_dev __test_i2c_read32_end[];
 extern const struct test_i2c_write_dev __test_i2c_write16[];
 extern const struct test_i2c_write_dev __test_i2c_write16_end[];
+extern const struct test_i2c_write_dev __test_i2c_write32[];
+extern const struct test_i2c_write_dev __test_i2c_write32_end[];
 extern const struct test_i2c_read_string_dev __test_i2c_read_string[];
 extern const struct test_i2c_read_string_dev __test_i2c_read_string_end[];
 
diff --git a/include/test_util.h b/include/test_util.h
index f8f50fcc76..b62e965563 100644
--- a/include/test_util.h
+++ b/include/test_util.h
@@ -256,6 +256,18 @@ struct test_i2c_write_dev {
 	__attribute__((section(".rodata.test_i2c.write16")))		\
 		= {routine}
 
+/* Register an I2C 32-bit read function. */
+#define DECLARE_TEST_I2C_READ32(routine)				\
+	const struct test_i2c_read_dev __test_i2c_read32_##routine	\
+	__attribute__((section(".rodata.test_i2c.read32")))		\
+		= {routine}
+
+/* Register an I2C 32-bit write function. */
+#define DECLARE_TEST_I2C_WRITE32(routine)				\
+	const struct test_i2c_write_dev __test_i2c_write32_##routine	\
+	__attribute__((section(".rodata.test_i2c.write32")))		\
+		= {routine}
+
 #define DECLARE_TEST_I2C_READ_STRING(routine)				\
 	const struct test_i2c_read_string_dev __test_i2c_rs_##routine	\
 	__attribute__((section(".rodata.test_i2c.read_string")))	\
diff --git a/test/stress.c b/test/stress.c
index 58a727adbe..5e31d4e466 100644
--- a/test/stress.c
+++ b/test/stress.c
@@ -98,6 +98,12 @@ static int test_i2c(void)
 	else if (param->width == 16 && param->data >= 0)
 		res = i2c_write16(param->port, param->addr,
 				  param->offset, param->data);
+	else if (param->width == 32 && param->data == -1)
+		res = i2c_read32(param->port, param->addr,
+				 param->offset, &dummy_data);
+	else if (param->width == 32 && param->data >= 0)
+		res = i2c_write32(param->port, param->addr,
+				  param->offset, param->data);
 
 	return res;
 }