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From: Guenter Roeck <linux@roeck-us.net>
To: Hardware Monitoring <linux-hwmon@vger.kernel.org>
Cc: Jean Delvare <jdelvare@suse.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Subject: [PATCH 08/11] hwmon: (max6650) Read non-volatile registers only once
Date: Tue, 23 Apr 2019 06:33:08 -0700
Message-ID: <1556026391-15360-8-git-send-email-linux@roeck-us.net> (raw)
In-Reply-To: <1556026391-15360-1-git-send-email-linux@roeck-us.net>

Only tachometer and alarm status registers are modified by the chip.
All other registers only need to be read only once, and reading them
repeatedly does not add any value.

Cc: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/max6650.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c
index 301184172ab1..7c8b1b8ededc 100644
--- a/drivers/hwmon/max6650.c
+++ b/drivers/hwmon/max6650.c
@@ -176,17 +176,10 @@ static struct max6650_data *max6650_update_device(struct device *dev)
 	mutex_lock(&data->update_lock);
 
 	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
-		data->speed = i2c_smbus_read_byte_data(client,
-						       MAX6650_REG_SPEED);
-		data->config = i2c_smbus_read_byte_data(client,
-							MAX6650_REG_CONFIG);
 		for (i = 0; i < data->nr_fans; i++) {
 			data->tach[i] = i2c_smbus_read_byte_data(client,
 								 tach_reg[i]);
 		}
-		data->count = i2c_smbus_read_byte_data(client,
-							MAX6650_REG_COUNT);
-		data->dac = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC);
 
 		/*
 		 * Alarms are cleared on read in case the condition that
@@ -435,8 +428,22 @@ static int max6650_init_client(struct max6650_data *data,
 		dev_err(dev, "Config write error, aborting.\n");
 		return err;
 	}
-
 	data->config = reg;
+
+	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_SPEED);
+	if (reg < 0) {
+		dev_err(dev, "Failed to read speed register, aborting.\n");
+		return reg;
+	}
+	data->speed = reg;
+
+	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC);
+	if (reg < 0) {
+		dev_err(dev, "Failed to read DAC register, aborting.\n");
+		return reg;
+	}
+	data->dac = reg;
+
 	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT);
 	if (reg < 0) {
 		dev_err(dev, "Failed to read count register, aborting.\n");
-- 
2.7.4


  parent reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-23 13:33 [PATCH 01/11] hwmon: (max6650) Use devm_add_action to unregister thermal device Guenter Roeck
2019-04-23 13:33 ` [PATCH 02/11] hwmon: (max6650) Introduce pwm_to_dac and dac_to_pwm Guenter Roeck
2019-04-23 15:23   ` Jean-Francois Dagenais
2019-04-23 17:02     ` Guenter Roeck
2019-04-23 13:33 ` [PATCH 03/11] hwmon: (max6650) Improve error handling in max6650_init_client Guenter Roeck
2019-04-23 13:33 ` [PATCH 04/11] hwmon: (max6650) Declare valid as boolean Guenter Roeck
2019-04-23 13:33 ` [PATCH 05/11] hwmon: (max6650) Cache alarm_en register Guenter Roeck
2019-04-23 13:33 ` [PATCH 06/11] hwmon: (max6650) Simplify alarm handling Guenter Roeck
2019-04-23 13:33 ` [PATCH 07/11] hwmon: (max6650) Convert to use devm_hwmon_device_register_with_info Guenter Roeck
2019-04-24 13:42   ` Guenter Roeck
2019-04-23 13:33 ` Guenter Roeck [this message]
2019-04-23 13:33 ` [PATCH 09/11] hwmon: (max6650) Improve error handling in max6650_update_device Guenter Roeck
2019-04-23 13:33 ` [PATCH 10/11] hwmon: (max6650) Use SPDX license identifier Guenter Roeck
2019-04-23 13:33 ` [PATCH 11/11] hwmon: (max6650) Fix minor formatting issues Guenter Roeck
2019-04-23 14:38   ` Jean-Francois Dagenais
2019-04-23 15:18     ` Guenter Roeck

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