[RFC/RFT PATCH RESEND] i2c: replace i2c_new_secondary_device with an ERR_PTR variant

From: Wolfram Sang
Date: Thu Jun 20 2019 - 16:48:49 EST


In the general move to have i2c_new_*_device functions which return
ERR_PTR instead of NULL, this patch converts i2c_new_secondary_device().

There are only few users, so this patch converts the I2C core and all
users in one go. The function gets renamed to i2c_new_ancillary_device()
so out-of-tree users will get a build failure to understand they need to
adapt their error checking code.

Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
---

Sorry for the resend. I missed to add quite some relevant ppl to cc.

This patch is RFC for now because:

* there is one FIXME blob which I can only remove after a missing
header update which I will try to get into v5.2-rc6

* I wanted to check if media-maintainers agree to let me apply
this via the I2C tree?

* maybe someone with ADV HW is willing to test this?

The patch is based on v5.2-rc5 and tested with a Renesas Lager board
(R-Car H2) and a tweaked DA9063 driver. I don't have any of these ADV
devices properly set up so the code is only build tested.

If this is acceptable, I likely will add a patch adding a devm_ variant
of this new function to the patch stack and convert the users, too.

I think this new i2c_new_ancillary_device() should replace
i2c_new_dummy() in quite some places later. But we will see...

drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 18 +++++++++---------
drivers/i2c/i2c-core-base.c | 10 +++++-----
drivers/media/i2c/adv748x/adv748x-core.c | 6 +++---
drivers/media/i2c/adv7604.c | 12 ++++++++----
include/linux/i2c.h | 2 +-
5 files changed, 26 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
index f6d2681f6927..9e13e466e72c 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
@@ -981,10 +981,10 @@ static int adv7511_init_cec_regmap(struct adv7511 *adv)
{
int ret;

- adv->i2c_cec = i2c_new_secondary_device(adv->i2c_main, "cec",
+ adv->i2c_cec = i2c_new_ancillary_device(adv->i2c_main, "cec",
ADV7511_CEC_I2C_ADDR_DEFAULT);
- if (!adv->i2c_cec)
- return -EINVAL;
+ if (IS_ERR(adv->i2c_cec))
+ return PTR_ERR(adv->i2c_cec);
i2c_set_clientdata(adv->i2c_cec, adv);

adv->regmap_cec = devm_regmap_init_i2c(adv->i2c_cec,
@@ -1165,20 +1165,20 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id)

adv7511_packet_disable(adv7511, 0xffff);

- adv7511->i2c_edid = i2c_new_secondary_device(i2c, "edid",
+ adv7511->i2c_edid = i2c_new_ancillary_device(i2c, "edid",
ADV7511_EDID_I2C_ADDR_DEFAULT);
- if (!adv7511->i2c_edid) {
- ret = -EINVAL;
+ if (IS_ERR(adv7511->i2c_edid)) {
+ ret = PTR_ERR(adv7511->i2c_edid);
goto uninit_regulators;
}

regmap_write(adv7511->regmap, ADV7511_REG_EDID_I2C_ADDR,
adv7511->i2c_edid->addr << 1);

- adv7511->i2c_packet = i2c_new_secondary_device(i2c, "packet",
+ adv7511->i2c_packet = i2c_new_ancillary_device(i2c, "packet",
ADV7511_PACKET_I2C_ADDR_DEFAULT);
- if (!adv7511->i2c_packet) {
- ret = -EINVAL;
+ if (IS_ERR(adv7511->i2c_packet)) {
+ ret = PTR_ERR(adv7511->i2c_packet);
goto err_i2c_unregister_edid;
}

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index e77bab2fb467..8b7855f3a199 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -965,7 +965,7 @@ struct i2c_client *devm_i2c_new_dummy_device(struct device *dev,
EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);

/**
- * i2c_new_secondary_device - Helper to get the instantiated secondary address
+ * i2c_new_ancillary_device - Helper to get the instantiated secondary address
* and create the associated device
* @client: Handle to the primary client
* @name: Handle to specify which secondary address to get
@@ -984,9 +984,9 @@ EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);
* cell whose "reg-names" value matches the slave name.
*
* This returns the new i2c client, which should be saved for later use with
- * i2c_unregister_device(); or NULL to indicate an error.
+ * i2c_unregister_device(); or an ERR_PTR to describe the error.
*/
-struct i2c_client *i2c_new_secondary_device(struct i2c_client *client,
+struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client,
const char *name,
u16 default_addr)
{
@@ -1001,9 +1001,9 @@ struct i2c_client *i2c_new_secondary_device(struct i2c_client *client,
}

dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
- return i2c_new_dummy(client->adapter, addr);
+ return i2c_new_dummy_device(client->adapter, addr);
}
-EXPORT_SYMBOL_GPL(i2c_new_secondary_device);
+EXPORT_SYMBOL_GPL(i2c_new_ancillary_device);

/* ------------------------------------------------------------------------- */

diff --git a/drivers/media/i2c/adv748x/adv748x-core.c b/drivers/media/i2c/adv748x/adv748x-core.c
index f57cd77a32fa..2567de2b0037 100644
--- a/drivers/media/i2c/adv748x/adv748x-core.c
+++ b/drivers/media/i2c/adv748x/adv748x-core.c
@@ -183,14 +183,14 @@ static int adv748x_initialise_clients(struct adv748x_state *state)
int ret;

for (i = ADV748X_PAGE_DPLL; i < ADV748X_PAGE_MAX; ++i) {
- state->i2c_clients[i] = i2c_new_secondary_device(
+ state->i2c_clients[i] = i2c_new_ancillary_device(
state->client,
adv748x_default_addresses[i].name,
adv748x_default_addresses[i].default_addr);

- if (state->i2c_clients[i] == NULL) {
+ if (IS_ERR(state->i2c_clients[i])) {
adv_err(state, "failed to create i2c client %u\n", i);
- return -ENOMEM;
+ return PTR_ERR(state->i2c_clients[i]);
}

ret = adv748x_configure_regmap(state, i);
diff --git a/drivers/media/i2c/adv7604.c b/drivers/media/i2c/adv7604.c
index 28a84bf9f8a9..ad68f24a369f 100644
--- a/drivers/media/i2c/adv7604.c
+++ b/drivers/media/i2c/adv7604.c
@@ -2881,11 +2881,15 @@ static struct i2c_client *adv76xx_dummy_client(struct v4l2_subdev *sd,
new_client = i2c_new_dummy(client->adapter,
pdata->i2c_addresses[page]);
else
- new_client = i2c_new_secondary_device(client,
+ new_client = i2c_new_ancillary_device(client,
adv76xx_default_addresses[page].name,
adv76xx_default_addresses[page].default_addr);

- if (new_client)
+ /* FIXME: can be removed once i2c_new_dummy_device hits upstream */
+ if (!new_client)
+ new_client = ERR_PTR(-ENOENT);
+
+ if (!IS_ERR(new_client))
io_write(sd, io_reg, new_client->addr << 1);

return new_client;
@@ -3520,8 +3524,8 @@ static int adv76xx_probe(struct i2c_client *client,
continue;

state->i2c_clients[i] = adv76xx_dummy_client(sd, i);
- if (!state->i2c_clients[i]) {
- err = -EINVAL;
+ if (IS_ERR(state->i2c_clients[i])) {
+ err = PTR_ERR(state->i2c_clients[i]);
v4l2_err(sd, "failed to create i2c client %u\n", i);
goto err_i2c;
}
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index fa5552c2307b..ebbe024dd9e0 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -473,7 +473,7 @@ extern struct i2c_client *
devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);

extern struct i2c_client *
-i2c_new_secondary_device(struct i2c_client *client,
+i2c_new_ancillary_device(struct i2c_client *client,
const char *name,
u16 default_addr);

--
2.20.1