Introduce two new RATP commands that allow running i2c read/write
operations, very similar in format to the already existing md/mw
RATP commands.
The messages are defined with a fixed 16-bit long register field, but
it will only be treated as a 16-bit address if I2C_FLAG_WIDE_ADDRESS
is set in the message flags field. If this flag is unset, the start
register address is assumed 8-bit long.
If the message includes the I2C_FLAG_MASTER_MODE flag, the start
register field is ignored and a i2c master send/receive operation is
performed.
Signed-off-by: Aleksander Morgado <aleksander@xxxxxxxxxxxxx>
---
common/ratp/Makefile | 1 +
common/ratp/i2c.c | 281 +++++++++++++++++++++++++++++++++++++++++++
include/ratp_bb.h | 4 +
3 files changed, 286 insertions(+)
create mode 100644 common/ratp/i2c.c
diff --git a/common/ratp/Makefile b/common/ratp/Makefile
index 2c6d674f6..0234b55c1 100644
--- a/common/ratp/Makefile
+++ b/common/ratp/Makefile
@@ -4,3 +4,4 @@ obj-y += getenv.o
obj-y += md.o
obj-y += mw.o
obj-y += reset.o
+obj-y += i2c.o
diff --git a/common/ratp/i2c.c b/common/ratp/i2c.c
new file mode 100644
index 000000000..b8d055b67
--- /dev/null
+++ b/common/ratp/i2c.c
@@ -0,0 +1,281 @@
+/*
+ * Copyright (c) 2011-2018 Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>, Pengutronix
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <common.h>
+#include <ratp_bb.h>
+#include <init.h>
+#include <driver.h>
+#include <malloc.h>
+#include <errno.h>
+#include <i2c/i2c.h>
+
+/* NOTE:
+ * - Fixed-size fields (e.g. integers) are given just after the header.
+ * - Variable-length fields are stored inside the buffer[] and their position
+ * within the buffer[] and their size are given as fixed-sized fields after
+ * the header.
+ * The message may be extended at any time keeping backwards compatibility,
+ * as the position of the buffer[] is given by the buffer_offset field. i.e.
+ * increasing the buffer_offset field we can extend the fixed-sized section
+ * to add more fields.
+ */
+
+#define I2C_FLAG_WIDE_ADDRESS (1 << 0)
+#define I2C_FLAG_MASTER_MODE (1 << 1)
+
+struct ratp_bb_i2c_read_request {
+ struct ratp_bb header;
+ uint16_t buffer_offset;
+ uint8_t bus;
+ uint8_t addr;
+ uint16_t reg;
+ uint8_t flags;
+ uint16_t size;
+ uint8_t buffer[];
+} __attribute__((packed));
+
+struct ratp_bb_i2c_read_response {
+ struct ratp_bb header;
+ uint16_t buffer_offset;
+ uint32_t errno;
+ uint16_t data_size;
+ uint16_t data_offset;
+ uint8_t buffer[];
+} __attribute__((packed));
+
+struct ratp_bb_i2c_write_request {
+ struct ratp_bb header;
+ uint16_t buffer_offset;
+ uint8_t bus;
+ uint8_t addr;
+ uint16_t reg;
+ uint8_t flags;
+ uint16_t data_size;
+ uint16_t data_offset;
+ uint8_t buffer[];
+} __attribute__((packed));
+
+struct ratp_bb_i2c_write_response {
+ struct ratp_bb header;
+ uint16_t buffer_offset;
+ uint32_t errno;
+ uint16_t written;
+ uint8_t buffer[];
+} __attribute__((packed));
+
+static int ratp_cmd_i2c_read(const struct ratp_bb *req, int req_len,
+ struct ratp_bb **rsp, int *rsp_len)
+{
+ struct ratp_bb_i2c_read_request *i2c_read_req = (struct ratp_bb_i2c_read_request *)req;
+ struct ratp_bb_i2c_read_response *i2c_read_rsp;
+ struct i2c_adapter *adapter;
+ struct i2c_client client;
+ uint16_t buffer_offset;
+ int i2c_read_rsp_len;
+ uint16_t reg;
+ uint16_t size;
+ uint32_t wide = 0;
+ int ret = 0;
+
+ /* At least message header should be valid */
+ if (req_len < sizeof(*i2c_read_req)) {
+ printf("ratp i2c read ignored: size mismatch (%d < %zu)\n",
+ req_len, sizeof (*i2c_read_req));
+ ret = -EINVAL;
+ goto out_rsp;
+ }
+
+ /* We don't require any buffer here, but just validate buffer position and size */
+ buffer_offset = be16_to_cpu(i2c_read_req->buffer_offset);
+ if (buffer_offset != req_len) {
+ printf("ratp i2c read ignored: invalid buffer offset (%hu != %d)\n",
+ buffer_offset, req_len);
+ ret = -EINVAL;
+ goto out_rsp;
+ }
+
+ reg = be16_to_cpu (i2c_read_req->reg);
+ size = be16_to_cpu (i2c_read_req->size);
+ if (i2c_read_req->flags & I2C_FLAG_WIDE_ADDRESS)
+ wide = I2C_ADDR_16_BIT;
+
+out_rsp:
+ /* Avoid reading anything on error */
+ if (ret != 0)
+ size = 0;
+
+ i2c_read_rsp_len = sizeof(*i2c_read_rsp) + size;
+ i2c_read_rsp = xzalloc(i2c_read_rsp_len);
+ i2c_read_rsp->header.type = cpu_to_be16(BB_RATP_TYPE_I2C_READ_RETURN);
+ i2c_read_rsp->buffer_offset = cpu_to_be16(sizeof(*i2c_read_rsp));
+ i2c_read_rsp->data_offset = 0;
+
+ /* Don't read anything on error or if 0 bytes were requested */
+ if (size > 0) {
+ adapter = i2c_get_adapter(i2c_read_req->bus);
+ if (!adapter) {
+ printf("ratp i2c read ignored: i2c bus %u not found\n", i2c_read_req->bus);
+ ret = -ENODEV;
+ goto out;
+ }
+
+ client.adapter = adapter;
+ client.addr = i2c_read_req->addr;
+
+ if (i2c_read_req->flags & I2C_FLAG_MASTER_MODE) {
+ ret = i2c_master_recv(&client, i2c_read_rsp->buffer, size);
+ } else {
+ ret = i2c_read_reg(&client, reg | wide, i2c_read_rsp->buffer, size);
+ }
+ if (ret != size) {
+ printf("ratp i2c read ignored: not all bytes read (%u < %u)\n", ret, size);
+ ret = -EIO;
+ goto out;
+ }
+ ret = 0;
+ }
+
+out:
+ if (ret != 0) {
+ i2c_read_rsp->data_size = 0;
+ i2c_read_rsp->errno = cpu_to_be32(ret);
+ i2c_read_rsp_len = sizeof(*i2c_read_rsp);
+ } else {
+ i2c_read_rsp->data_size = cpu_to_be16(size);
+ i2c_read_rsp->errno = 0;
+ }
+
+ *rsp = (struct ratp_bb *)i2c_read_rsp;
+ *rsp_len = i2c_read_rsp_len;
+
+ return ret;
+}
+
+BAREBOX_RATP_CMD_START(I2C_READ)
+ .request_id = BB_RATP_TYPE_I2C_READ,
+ .response_id = BB_RATP_TYPE_I2C_READ_RETURN,
+ .cmd = ratp_cmd_i2c_read
+BAREBOX_RATP_CMD_END
+
+
+static int ratp_cmd_i2c_write(const struct ratp_bb *req, int req_len,
+ struct ratp_bb **rsp, int *rsp_len)
+{
+ struct ratp_bb_i2c_write_request *i2c_write_req = (struct ratp_bb_i2c_write_request *)req;
+ struct ratp_bb_i2c_write_response *i2c_write_rsp;
+ struct i2c_adapter *adapter;
+ struct i2c_client client;
+ uint8_t *buffer;
+ uint16_t buffer_offset;
+ uint16_t buffer_size;
+ uint16_t reg;
+ uint16_t data_offset;
+ uint16_t data_size;
+ uint32_t wide = 0;
+ int ret = 0;
+ int written = 0;
+
+ /* At least message header should be valid */
+ if (req_len < sizeof(*i2c_write_req)) {
+ printf("ratp i2c write ignored: size mismatch (%d < %zu)\n",
+ req_len, sizeof (*i2c_write_req));
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Validate buffer position and size */
+ buffer_offset = be16_to_cpu(i2c_write_req->buffer_offset);
+ if (req_len < buffer_offset) {
+ printf("ratp i2c write ignored: invalid buffer offset (%d < %hu)\n",
+ req_len, buffer_offset);
+ ret = -EINVAL;
+ goto out;
+ }
+ buffer_size = req_len - buffer_offset;
+ buffer = ((uint8_t *)i2c_write_req) + buffer_offset;
+
+ /* Validate data position and size */
+ data_offset = be16_to_cpu(i2c_write_req->data_offset);
+ if (data_offset != 0) {
+ printf("ratp i2c write ignored: invalid data offset\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ data_size = be16_to_cpu(i2c_write_req->data_size);
+ if (!data_size) {
+ /* Success */
+ goto out;
+ }
+
+ /* Validate buffer size */
+ if (buffer_size < data_size) {
+ printf("ratp i2c write ignored: size mismatch (%d < %hu): data not fully given\n",
+ buffer_size, data_size);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ reg = be16_to_cpu (i2c_write_req->reg);
+ if (i2c_write_req->flags & I2C_FLAG_WIDE_ADDRESS)
+ wide = I2C_ADDR_16_BIT;
+
+ adapter = i2c_get_adapter(i2c_write_req->bus);
+ if (!adapter) {
+ printf("ratp i2c write ignored: i2c bus %u not found\n", i2c_write_req->bus);
+ ret = -ENODEV;
+ goto out;
+ }
+
+ client.adapter = adapter;
+ client.addr = i2c_write_req->addr;
+
+ if (i2c_write_req->flags & I2C_FLAG_MASTER_MODE) {
+ written = i2c_master_send(&client, &buffer[data_offset], data_size);
+ } else {
+ written = i2c_write_reg(&client, reg | wide, &buffer[data_offset], data_size);
+ }
+
+ if (written != data_size) {
+ printf("ratp i2c write ignored: not all bytes written (%u < %u)\n", ret, data_size);
+ ret = -EIO;
+ goto out;
+ }
+
+out:
+ i2c_write_rsp = xzalloc(sizeof(*i2c_write_rsp));
+ i2c_write_rsp->header.type = cpu_to_be16(BB_RATP_TYPE_I2C_WRITE_RETURN);
+ i2c_write_rsp->buffer_offset = cpu_to_be16(sizeof(*i2c_write_rsp)); /* n/a */
+
+ if (ret != 0) {
+ i2c_write_rsp->written = 0;
+ i2c_write_rsp->errno = cpu_to_be32(ret);
+ } else {
+ i2c_write_rsp->written = cpu_to_be16((uint16_t)written);
+ i2c_write_rsp->errno = 0;
+ }
+
+ *rsp = (struct ratp_bb *)i2c_write_rsp;
+ *rsp_len = sizeof(*i2c_write_rsp);
+
+ return ret;
+}
+
+BAREBOX_RATP_CMD_START(I2C_WRITE)
+ .request_id = BB_RATP_TYPE_I2C_WRITE,
+ .response_id = BB_RATP_TYPE_I2C_WRITE_RETURN,
+ .cmd = ratp_cmd_i2c_write
+BAREBOX_RATP_CMD_END
diff --git a/include/ratp_bb.h b/include/ratp_bb.h
index 3a80cf6ae..32b8040b6 100644
--- a/include/ratp_bb.h
+++ b/include/ratp_bb.h
@@ -17,6 +17,10 @@
#define BB_RATP_TYPE_MW 12
#define BB_RATP_TYPE_MW_RETURN 13
#define BB_RATP_TYPE_RESET 14
+#define BB_RATP_TYPE_I2C_READ 15
+#define BB_RATP_TYPE_I2C_READ_RETURN 16
+#define BB_RATP_TYPE_I2C_WRITE 17
+#define BB_RATP_TYPE_I2C_WRITE_RETURN 18
struct ratp_bb {
uint16_t type;
--
2.18.0
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