From 2c964a2e159880c921a33f51f493a3a257d4bfce Mon Sep 17 00:00:00 2001
From: Nikita Shubin <n.shubin@yadro.com>
Date: Wed, 10 Nov 2021 12:42:27 +0300
Subject: lib: utils/i2c: Add generic I2C configuration library
Helper library to keep track of registered I2C adapters,
identified by dts offset, basic send/read functions and
adapter configuration (enable, set dividers, etc...).
Tested-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Tested-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Nikita Shubin <n.shubin@yadro.com>
---
include/sbi_utils/i2c/i2c.h | 85 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 85 insertions(+)
create mode 100644 include/sbi_utils/i2c/i2c.h
(limited to 'include')
diff --git a/include/sbi_utils/i2c/i2c.h b/include/sbi_utils/i2c/i2c.h
new file mode 100644
index 0000000..5a70364
--- /dev/null
+++ b/include/sbi_utils/i2c/i2c.h
@@ -0,0 +1,85 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 YADRO
+ *
+ * Authors:
+ * Nikita Shubin <n.shubin@yadro.com>
+ */
+
+#ifndef __I2C_H__
+#define __I2C_H__
+
+#include <sbi/sbi_types.h>
+#include <sbi/sbi_list.h>
+
+/** Representation of a I2C adapter */
+struct i2c_adapter {
+ /** Pointer to I2C driver owning this I2C adapter */
+ void *driver;
+
+ /** Unique ID of the I2C adapter assigned by the driver */
+ int id;
+
+ /**
+ * Send buffer to given address, register
+ *
+ * @return 0 on success and negative error code on failure
+ */
+ int (*write)(struct i2c_adapter *ia, uint8_t addr, uint8_t reg,
+ uint8_t *buffer, int len);
+
+ /**
+ * Read buffer from given address, register
+ *
+ * @return 0 on success and negative error code on failure
+ */
+ int (*read)(struct i2c_adapter *ia, uint8_t addr, uint8_t reg,
+ uint8_t *buffer, int len);
+
+ /** List */
+ struct sbi_dlist node;
+};
+
+static inline struct i2c_adapter *to_i2c_adapter(struct sbi_dlist *node)
+{
+ return container_of(node, struct i2c_adapter, node);
+}
+
+/** Find a registered I2C adapter */
+struct i2c_adapter *i2c_adapter_find(int id);
+
+/** Register I2C adapter */
+int i2c_adapter_add(struct i2c_adapter *ia);
+
+/** Un-register I2C adapter */
+void i2c_adapter_remove(struct i2c_adapter *ia);
+
+/** Send to device on I2C adapter bus */
+int i2c_adapter_write(struct i2c_adapter *ia, uint8_t addr, uint8_t reg,
+ uint8_t *buffer, int len);
+
+/** Read from device on I2C adapter bus */
+int i2c_adapter_read(struct i2c_adapter *ia, uint8_t addr, uint8_t reg,
+ uint8_t *buffer, int len);
+
+static inline int i2c_adapter_reg_write(struct i2c_adapter *ia, uint8_t addr,
+ uint8_t reg, uint8_t val)
+{
+ return i2c_adapter_write(ia, addr, reg, &val, 1);
+}
+
+static inline int i2c_adapter_reg_read(struct i2c_adapter *ia, uint8_t addr,
+ uint8_t reg, uint8_t *val)
+{
+ uint8_t buf;
+ int ret = i2c_adapter_read(ia, addr, reg, &buf, 1);
+
+ if (ret)
+ return ret;
+
+ *val = buf;
+ return 0;
+}
+
+#endif
--
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