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From:   Marius Zachmann <mail@mariuszachmann.de>
To:     Guenter Roeck <linux@roeck-us.net>
Cc:     Marius Zachmann <mail@mariuszachmann.de>,
        Jean Delvare <jdelvare@suse.com>,
        Jonathan Corbet <corbet@lwn.net>, linux-hwmon@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] hwmon: corsair-cpro: add fan_target
Date:   Thu,  9 Jul 2020 16:14:13 +0200
Message-Id: <20200709141413.30790-1-mail@mariuszachmann.de>
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This adds fan_target entries to the corsair-cpro driver.
Reading the attribute from the device does not seem possible, so
it returns the last set value. (same as pwm)

send_usb_cmd now has one more argument, which is needed for the
  fan_target command.

Signed-off-by: Marius Zachmann <mail@mariuszachmann.de>
---
Change from v1:
- use clamp_val instead of bounds checking

---
 Documentation/hwmon/corsair-cpro.rst |  3 ++
 drivers/hwmon/corsair-cpro.c         | 61 ++++++++++++++++++++++------
 2 files changed, 52 insertions(+), 12 deletions(-)

diff --git a/Documentation/hwmon/corsair-cpro.rst b/Documentation/hwmon/corsair-cpro.rst
index 5913e23d764c..78820156f07d 100644
--- a/Documentation/hwmon/corsair-cpro.rst
+++ b/Documentation/hwmon/corsair-cpro.rst
@@ -33,6 +33,9 @@ in2_input		Voltage on SATA 3.3v
 temp[1-4]_input		Temperature on connected temperature sensors
 fan[1-6]_input		Connected fan rpm.
 fan[1-6]_label		Shows fan type as detected by the device.
+fan[1-6]_target		Sets fan speed target rpm.
+			When reading, it reports the last value if it was set by the driver.
+			Otherwise returns 0.
 pwm[1-6]		Sets the fan speed. Values from 0-255.
 			When reading, it reports the last value if it was set by the driver.
 			Otherwise returns 0.
diff --git a/drivers/hwmon/corsair-cpro.c b/drivers/hwmon/corsair-cpro.c
index a22583acc229..fe625190e3a1 100644
--- a/drivers/hwmon/corsair-cpro.c
+++ b/drivers/hwmon/corsair-cpro.c
@@ -5,8 +5,8 @@
  */

 #include <linux/bitops.h>
-#include <linux/kernel.h>
 #include <linux/hwmon.h>
+#include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
@@ -51,6 +51,12 @@
 					 * send: byte 1 is fan number
 					 * send: byte 2 is percentage from 0 - 100
 					 */
+#define CTL_SET_FAN_TARGET	0x24	/*
+					 * set target rpm
+					 * send: byte 1 is fan number
+					 * send: byte 2-3 is target
+					 * device accepts all values from 0x00 - 0xFFFF
+					 */

 #define NUM_FANS		6
 #define NUM_TEMP_SENSORS	4
@@ -60,13 +66,14 @@ struct ccp_device {
 	struct mutex mutex; /* whenever buffer is used, lock before send_usb_cmd */
 	u8 *buffer;
 	int pwm[6];
+	int target[6];
 	DECLARE_BITMAP(temp_cnct, NUM_TEMP_SENSORS);
 	DECLARE_BITMAP(fan_cnct, NUM_FANS);
 	char fan_label[6][LABEL_LENGTH];
 };

 /* send command, check for error in response, response in ccp->buffer */
-static int send_usb_cmd(struct ccp_device *ccp, u8 command, u8 byte1, u8 byte2)
+static int send_usb_cmd(struct ccp_device *ccp, u8 command, u8 byte1, u8 byte2, u8 byte3)
 {
 	int actual_length;
 	int ret;
@@ -75,6 +82,7 @@ static int send_usb_cmd(struct ccp_device *ccp, u8 command, u8 byte1, u8 byte2)
 	ccp->buffer[0] = command;
 	ccp->buffer[1] = byte1;
 	ccp->buffer[2] = byte2;
+	ccp->buffer[3] = byte3;

 	ret = usb_bulk_msg(ccp->udev, usb_sndintpipe(ccp->udev, 2), ccp->buffer, OUT_BUFFER_SIZE,
 			   &actual_length, 1000);
@@ -103,7 +111,7 @@ static int get_data(struct ccp_device *ccp, int command, int channel)

 	mutex_lock(&ccp->mutex);

-	ret = send_usb_cmd(ccp, command, channel, 0);
+	ret = send_usb_cmd(ccp, command, channel, 0, 0);
 	if (ret)
 		goto out_unlock;

@@ -128,7 +136,22 @@ static int set_pwm(struct ccp_device *ccp, int channel, long val)

 	mutex_lock(&ccp->mutex);

-	ret = send_usb_cmd(ccp, CTL_SET_FAN_FPWM, channel, val);
+	ret = send_usb_cmd(ccp, CTL_SET_FAN_FPWM, channel, val, 0);
+
+	mutex_unlock(&ccp->mutex);
+	return ret;
+}
+
+static int set_target(struct ccp_device *ccp, int channel, long val)
+{
+	int ret;
+
+	val = clamp_val(val, 0, 0xFFFF);
+	ccp->target[channel] = val;
+
+	mutex_lock(&ccp->mutex);
+
+	ret = send_usb_cmd(ccp, CTL_SET_FAN_TARGET, channel, val >> 8, val);

 	mutex_unlock(&ccp->mutex);
 	return ret;
@@ -183,6 +206,11 @@ static int ccp_read(struct device *dev, enum hwmon_sensor_types type,
 				return ret;
 			*val = ret;
 			return 0;
+		case hwmon_fan_target:
+			/* how to read target values from the device is unknown */
+			/* driver returns last set value or 0			*/
+			*val = ccp->target[channel];
+			return 0;
 		default:
 			break;
 		}
@@ -231,6 +259,13 @@ static int ccp_write(struct device *dev, enum hwmon_sensor_types type,
 			break;
 		}
 		break;
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_target:
+			return set_target(ccp, channel, val);
+		default:
+			break;
+		}
 	default:
 		break;
 	}
@@ -266,6 +301,8 @@ static umode_t ccp_is_visible(const void *data, enum hwmon_sensor_types type,
 			return 0444;
 		case hwmon_fan_label:
 			return 0444;
+		case hwmon_fan_target:
+			return 0644;
 		default:
 			break;
 		}
@@ -313,12 +350,12 @@ static const struct hwmon_channel_info *ccp_info[] = {
 			   HWMON_T_INPUT
 			   ),
 	HWMON_CHANNEL_INFO(fan,
-			   HWMON_F_INPUT | HWMON_F_LABEL,
-			   HWMON_F_INPUT | HWMON_F_LABEL,
-			   HWMON_F_INPUT | HWMON_F_LABEL,
-			   HWMON_F_INPUT | HWMON_F_LABEL,
-			   HWMON_F_INPUT | HWMON_F_LABEL,
-			   HWMON_F_INPUT | HWMON_F_LABEL
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_TARGET
 			   ),
 	HWMON_CHANNEL_INFO(pwm,
 			   HWMON_PWM_INPUT,
@@ -348,7 +385,7 @@ static int get_fan_cnct(struct ccp_device *ccp)
 	int mode;
 	int ret;

-	ret = send_usb_cmd(ccp, CTL_GET_FAN_CNCT, 0, 0);
+	ret = send_usb_cmd(ccp, CTL_GET_FAN_CNCT, 0, 0, 0);
 	if (ret)
 		return ret;

@@ -385,7 +422,7 @@ static int get_temp_cnct(struct ccp_device *ccp)
 	int mode;
 	int ret;

-	ret = send_usb_cmd(ccp, CTL_GET_TMP_CNCT, 0, 0);
+	ret = send_usb_cmd(ccp, CTL_GET_TMP_CNCT, 0, 0, 0);
 	if (ret)
 		return ret;

--
2.27.0