crypto: atmel-ecc - factor out code that can be shared

In preparation of adding support for the random number generator in
Atmel atsha204a devices, refactor the existing atmel-ecc driver (which
drives hardware that is closely related) so we can share the basic
I2C and command queuing routines.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 75 insertions, 5 deletions

diff --git a/drivers/crypto/atmel-ecc.h b/drivers/crypto/atmel-i2c.h
index 643a3b947338..82de5166acfa 100644
--- a/drivers/crypto/atmel-ecc.h
+++ b/drivers/crypto/atmel-i2c.h
@@ -4,8 +4,8 @@
  * Author: Tudor Ambarus <tudor.ambarus@microchip.com>
  */
 
-#ifndef __ATMEL_ECC_H__
-#define __ATMEL_ECC_H__
+#ifndef __ATMEL_I2C_H__
+#define __ATMEL_I2C_H__
 
 #define ATMEL_ECC_PRIORITY		300
 
@@ -31,7 +31,7 @@
 #define MAX_RSP_SIZE			GENKEY_RSP_SIZE
 
 /**
- * atmel_ecc_cmd - structure used for communicating with the device.
+ * atmel_i2c_cmd - structure used for communicating with the device.
  * @word_addr: indicates the function of the packet sent to the device. This
  *             byte should have a value of COMMAND for normal operation.
  * @count    : number of bytes to be transferred to (or from) the device.
@@ -42,7 +42,7 @@
  * @rxsize   : size of the data received from i2c client.
  * @msecs    : command execution time in milliseconds
  */
-struct atmel_ecc_cmd {
+struct atmel_i2c_cmd {
 	u8 word_addr;
 	u8 count;
 	u8 opcode;
@@ -113,4 +113,74 @@ static const struct {
 #define ECDH_COUNT			71
 #define ECDH_PREFIX_MODE		0x00
 
-#endif /* __ATMEL_ECC_H__ */
+/* Used for binding tfm objects to i2c clients. */
+struct atmel_ecc_driver_data {
+	struct list_head i2c_client_list;
+	spinlock_t i2c_list_lock;
+} ____cacheline_aligned;
+
+/**
+ * atmel_i2c_client_priv - i2c_client private data
+ * @client              : pointer to i2c client device
+ * @i2c_client_list_node: part of i2c_client_list
+ * @lock                : lock for sending i2c commands
+ * @wake_token          : wake token array of zeros
+ * @wake_token_sz       : size in bytes of the wake_token
+ * @tfm_count           : number of active crypto transformations on i2c client
+ *
+ * Reads and writes from/to the i2c client are sequential. The first byte
+ * transmitted to the device is treated as the byte size. Any attempt to send
+ * more than this number of bytes will cause the device to not ACK those bytes.
+ * After the host writes a single command byte to the input buffer, reads are
+ * prohibited until after the device completes command execution. Use a mutex
+ * when sending i2c commands.
+ */
+struct atmel_i2c_client_priv {
+	struct i2c_client *client;
+	struct list_head i2c_client_list_node;
+	struct mutex lock;
+	u8 wake_token[WAKE_TOKEN_MAX_SIZE];
+	size_t wake_token_sz;
+	atomic_t tfm_count ____cacheline_aligned;
+};
+
+/**
+ * atmel_i2c_work_data - data structure representing the work
+ * @ctx : transformation context.
+ * @cbk : pointer to a callback function to be invoked upon completion of this
+ *        request. This has the form:
+ *        callback(struct atmel_i2c_work_data *work_data, void *areq, u8 status)
+ *        where:
+ *        @work_data: data structure representing the work
+ *        @areq     : optional pointer to an argument passed with the original
+ *                    request.
+ *        @status   : status returned from the i2c client device or i2c error.
+ * @areq: optional pointer to a user argument for use at callback time.
+ * @work: describes the task to be executed.
+ * @cmd : structure used for communicating with the device.
+ */
+struct atmel_i2c_work_data {
+	void *ctx;
+	struct i2c_client *client;
+	void (*cbk)(struct atmel_i2c_work_data *work_data, void *areq,
+		    int status);
+	void *areq;
+	struct work_struct work;
+	struct atmel_i2c_cmd cmd;
+};
+
+int atmel_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id);
+
+void atmel_i2c_enqueue(struct atmel_i2c_work_data *work_data,
+		       void (*cbk)(struct atmel_i2c_work_data *work_data,
+				   void *areq, int status),
+		       void *areq);
+
+int atmel_i2c_send_receive(struct i2c_client *client, struct atmel_i2c_cmd *cmd);
+
+void atmel_i2c_init_read_cmd(struct atmel_i2c_cmd *cmd);
+void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid);
+int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
+			    struct scatterlist *pubkey);
+
+#endif /* __ATMEL_I2C_H__ */