i3c: device: Add SETMWL/GETMWL and SETMRL/GETMRL support

Add the GETMRL/SETMRL and GETMWL/SETMWL CCC commands functions.
The functions are needed to configure maximum read/write length
for the specific I3C device.

Signed-off-by: Oleksandr Shulzhenko <oleksandr.shulzhenko.viktorovych@intel.com>

4 files changed, 159 insertions, 4 deletions

diff --git a/drivers/i3c/device.c b/drivers/i3c/device.c
index cf2055dc238c..e6fd40ec0448 100644
--- a/drivers/i3c/device.c
+++ b/drivers/i3c/device.c
@@ -348,3 +348,103 @@ int i3c_device_control_pec(struct i3c_device *dev, bool pec)
 	return i3c_dev_control_pec(dev->desc, pec);
 }
 EXPORT_SYMBOL_GPL(i3c_device_control_pec);
+
+/**
+ * i3c_device_setmrl_ccc() - set maximum read length
+ *
+ * @dev: I3C device to set the length for
+ * @info: I3C device info to fill the length in
+ * @read_len: maximum read length value to be set
+ * @ibi_len: maximum ibi payload length to be set
+ *
+ * Set I3C device maximum read length from I3C master device via corresponding CCC command
+ *
+ * Return: 0 in case of success, a negative error code otherwise.
+ */
+int i3c_device_setmrl_ccc(struct i3c_device *dev, struct i3c_device_info *info, __be16 read_len,
+			  u8 ibi_len)
+{
+	struct i3c_master_controller *master = i3c_dev_get_master(dev->desc);
+	int ret = -EINVAL;
+
+	i3c_bus_normaluse_lock(dev->bus);
+	if (master)
+		ret = i3c_master_setmrl_locked(master, info, read_len, ibi_len);
+	i3c_bus_normaluse_unlock(dev->bus);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(i3c_device_setmrl_ccc);
+
+/**
+ * i3c_device_setmwl_ccc() - set maximum write length
+ *
+ * @dev: I3C device to set the length for
+ * @info: I3C device info to fill the length in
+ * @write_len: maximum write length value to be set
+ *
+ * Set I3C device maximum write length from I3C master device via corresponding CCC command
+ *
+ * Return: 0 in case of success, a negative error code otherwise.
+ */
+int i3c_device_setmwl_ccc(struct i3c_device *dev, struct i3c_device_info *info, __be16 write_len)
+{
+	struct i3c_master_controller *master = i3c_dev_get_master(dev->desc);
+	int ret = -EINVAL;
+
+	i3c_bus_normaluse_lock(dev->bus);
+	if (master)
+		ret = i3c_master_setmwl_locked(master, info, write_len);
+	i3c_bus_normaluse_unlock(dev->bus);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(i3c_device_setmwl_ccc);
+
+/**
+ * i3c_device_getmrl_ccc() - get maximum read length
+ *
+ * @dev: I3C device to get the length for
+ * @info: I3C device info to fill the length in
+ *
+ * Receive I3C device maximum read length from I3C master device via corresponding CCC command
+ *
+ * Return: 0 in case of success, a negative error code otherwise.
+ */
+int i3c_device_getmrl_ccc(struct i3c_device *dev, struct i3c_device_info *info)
+{
+	struct i3c_master_controller *master = i3c_dev_get_master(dev->desc);
+	int ret = -EINVAL;
+
+	i3c_bus_normaluse_lock(dev->bus);
+	if (master)
+		ret = i3c_master_getmrl_locked(master, info);
+	i3c_bus_normaluse_unlock(dev->bus);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(i3c_device_getmrl_ccc);
+
+/**
+ * i3c_device_getmwl_ccc() - get maximum write length
+ *
+ * @dev: I3C device to get the length for
+ * @info: I3C device info to fill the length in
+ *
+ * Receive I3C device maximum write length from I3C master device via corresponding CCC command
+ *
+ * Return: 0 in case of success, a negative error code otherwise.
+ */
+int i3c_device_getmwl_ccc(struct i3c_device *dev, struct i3c_device_info *info)
+{
+	struct i3c_master_controller *master = i3c_dev_get_master(dev->desc);
+	int ret = -EINVAL;
+
+	i3c_bus_normaluse_lock(dev->bus);
+	if (master)
+		ret = i3c_master_getmwl_locked(master, info);
+	i3c_bus_normaluse_unlock(dev->bus);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(i3c_device_getmwl_ccc);
diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h
index 5e6bd53637e4..4da78b11b9ab 100644
--- a/drivers/i3c/internals.h
+++ b/drivers/i3c/internals.h
@@ -26,6 +26,12 @@ int i3c_dev_request_ibi_locked(struct i3c_dev_desc *dev,
 			       const struct i3c_ibi_setup *req);
 void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev);
 int i3c_dev_getstatus_locked(struct i3c_dev_desc *dev, struct i3c_device_info *info);
+int i3c_master_getmrl_locked(struct i3c_master_controller *master, struct i3c_device_info *info);
+int i3c_master_getmwl_locked(struct i3c_master_controller *master, struct i3c_device_info *info);
+int i3c_master_setmrl_locked(struct i3c_master_controller *master,
+			     struct i3c_device_info *info, __be16 read_len, u8 ibi_len);
+int i3c_master_setmwl_locked(struct i3c_master_controller *master,
+			     struct i3c_device_info *info, __be16 write_len);
 int i3c_for_each_dev(void *data, int (*fn)(struct device *, void *));
 int i3c_dev_generate_ibi_locked(struct i3c_dev_desc *dev, const u8 *data, int len);
 int i3c_dev_control_pec(struct i3c_dev_desc *dev, bool pec);
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 8ad15e2dcc62..11666adac6fb 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -1044,8 +1044,7 @@ static int i3c_master_sethid_locked(struct i3c_master_controller *master)
 	return ret;
 }
 
-static int i3c_master_getmrl_locked(struct i3c_master_controller *master,
-				    struct i3c_device_info *info)
+int i3c_master_getmrl_locked(struct i3c_master_controller *master, struct i3c_device_info *info)
 {
 	struct i3c_ccc_cmd_dest dest;
 	struct i3c_ccc_mrl *mrl;
@@ -1086,8 +1085,7 @@ out:
 	return ret;
 }
 
-static int i3c_master_getmwl_locked(struct i3c_master_controller *master,
-				    struct i3c_device_info *info)
+int i3c_master_getmwl_locked(struct i3c_master_controller *master, struct i3c_device_info *info)
 {
 	struct i3c_ccc_cmd_dest dest;
 	struct i3c_ccc_mwl *mwl;
@@ -1116,6 +1114,52 @@ out:
 	return ret;
 }
 
+int i3c_master_setmrl_locked(struct i3c_master_controller *master,
+			     struct i3c_device_info *info, __be16 read_len, u8 ibi_len)
+{
+	struct i3c_ccc_cmd_dest dest;
+	struct i3c_ccc_cmd cmd;
+	struct i3c_ccc_mrl *mrl;
+	int ret;
+
+	mrl = i3c_ccc_cmd_dest_init(&dest, info->dyn_addr, sizeof(*mrl));
+	if (!mrl)
+		return -ENOMEM;
+
+	mrl->read_len = read_len;
+	mrl->ibi_len = ibi_len;
+	info->max_read_len = mrl->read_len;
+	info->max_ibi_len = mrl->ibi_len;
+	i3c_ccc_cmd_init(&cmd, false, I3C_CCC_SETMRL(false), &dest, 1);
+
+	ret = i3c_master_send_ccc_cmd_locked(master, &cmd);
+	i3c_ccc_cmd_dest_cleanup(&dest);
+
+	return ret;
+}
+
+int i3c_master_setmwl_locked(struct i3c_master_controller *master,
+			     struct i3c_device_info *info, __be16 write_len)
+{
+	struct i3c_ccc_cmd_dest dest;
+	struct i3c_ccc_cmd cmd;
+	struct i3c_ccc_mwl *mwl;
+	int ret;
+
+	mwl = i3c_ccc_cmd_dest_init(&dest, info->dyn_addr, sizeof(*mwl));
+	if (!mwl)
+		return -ENOMEM;
+
+	mwl->len = write_len;
+	info->max_write_len = mwl->len;
+	i3c_ccc_cmd_init(&cmd, false, I3C_CCC_SETMWL(false), &dest, 1);
+
+	ret = i3c_master_send_ccc_cmd_locked(master, &cmd);
+	i3c_ccc_cmd_dest_cleanup(&dest);
+
+	return ret;
+}
+
 static int i3c_master_getmxds_locked(struct i3c_master_controller *master,
 				     struct i3c_device_info *info)
 {
diff --git a/include/linux/i3c/device.h b/include/linux/i3c/device.h
index 1bc9f65dbb6a..dad3829be66c 100644
--- a/include/linux/i3c/device.h
+++ b/include/linux/i3c/device.h
@@ -342,6 +342,11 @@ int i3c_device_enable_ibi(struct i3c_device *dev);
 int i3c_device_disable_ibi(struct i3c_device *dev);
 
 int i3c_device_getstatus_ccc(struct i3c_device *dev, struct i3c_device_info *info);
+int i3c_device_setmrl_ccc(struct i3c_device *dev, struct i3c_device_info *info, __be16 read_len,
+			  u8 ibi_len);
+int i3c_device_setmwl_ccc(struct i3c_device *dev, struct i3c_device_info *info, __be16 write_len);
+int i3c_device_getmrl_ccc(struct i3c_device *dev, struct i3c_device_info *info);
+int i3c_device_getmwl_ccc(struct i3c_device *dev, struct i3c_device_info *info);
 
 struct i3c_target_read_setup {
 	void (*handler)(struct i3c_device *dev, const u8 *data, size_t len);