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Sender: Guenter Roeck <groeck7@gmail.com>
From: Guenter Roeck <linux@roeck-us.net>
To: linux-hwmon@vger.kernel.org
Cc: Rob Herring <robh@kernel.org>,
	linux-kernel@vger.kernel.org,
	Peter Yin <peteryin.openbmc@gmail.com>,
	Potin Lai <potin.lai.pt@gmail.com>,
	Daniel Matyas <daniel.matyas@analog.com>,
	Andrew Davis <afd@ti.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	Guenter Roeck <linux@roeck-us.net>
Subject: [PATCH 3/4] hwmon: (pmbus/mp2856) Let enum chips start with index 0
Date: Mon, 10 Jun 2024 11:10:45 -0700
Message-Id: <20240610181046.1991436-4-linux@roeck-us.net>
In-Reply-To: <20240610181046.1991436-1-linux@roeck-us.net>
References: <20240610181046.1991436-1-linux@roeck-us.net>
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Earlier it was assumed that the data pointer in of_device_id must not start
with 0 (NULL) if i2c_get_match_data() is used. However, it turns out that
this is perfectly fine as long as there is also an i2c_device_id array with
the same data, which is used as fallback in that case.

Let enum chips start with 0 to avoid confusion against other drivers
where the enum starts with 0 and i2c_get_match_data() is used as well.

While doing that, remove chip_id from struct mp2856_data since it is only
used in the probe function, and typecast the result of i2c_get_match_data()
to kernel_ulong_t to avoid the double typecast.

Cc: Peter Yin <peteryin.openbmc@gmail.com>
Cc: Potin Lai <potin.lai.pt@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/pmbus/mp2856.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/hwmon/pmbus/mp2856.c b/drivers/hwmon/pmbus/mp2856.c
index 6969350f5d7d..41bb86667091 100644
--- a/drivers/hwmon/pmbus/mp2856.c
+++ b/drivers/hwmon/pmbus/mp2856.c
@@ -46,7 +46,7 @@
 
 #define MP2856_PAGE_NUM			2
 
-enum chips { mp2856 = 1, mp2857 };
+enum chips { mp2856, mp2857 };
 
 static const int mp2856_max_phases[][MP2856_PAGE_NUM] = {
 	[mp2856] = { MP2856_MAX_PHASE_RAIL1, MP2856_MAX_PHASE_RAIL2 },
@@ -66,7 +66,6 @@ struct mp2856_data {
 	int vout_format[MP2856_PAGE_NUM];
 	int curr_sense_gain[MP2856_PAGE_NUM];
 	int max_phases[MP2856_PAGE_NUM];
-	enum chips chip_id;
 };
 
 #define to_mp2856_data(x)	container_of(x, struct mp2856_data, info)
@@ -397,6 +396,7 @@ static int mp2856_probe(struct i2c_client *client)
 {
 	struct pmbus_driver_info *info;
 	struct mp2856_data *data;
+	enum chips chip_id;
 	int ret;
 
 	data = devm_kzalloc(&client->dev, sizeof(struct mp2856_data),
@@ -404,9 +404,9 @@ static int mp2856_probe(struct i2c_client *client)
 	if (!data)
 		return -ENOMEM;
 
-	data->chip_id = (enum chips)(uintptr_t)i2c_get_match_data(client);
+	chip_id = (kernel_ulong_t)i2c_get_match_data(client);
 
-	memcpy(data->max_phases, mp2856_max_phases[data->chip_id],
+	memcpy(data->max_phases, mp2856_max_phases[chip_id],
 	       sizeof(data->max_phases));
 
 	memcpy(&data->info, &mp2856_info, sizeof(*info));
-- 
2.39.2