From 38798884cb3ccd05b2a82299db865aeb7e7c059b Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
Date: Thu, 5 May 2022 15:46:07 +0100
Subject: [PATCH] hwmon: emc2305: fixups for driver submitted to mailing lists

The driver had a number of issues, checkpatch warnings/errors,
and other limitations, so fix these up to make it usable.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

hwmon: emc2305: Add calls to initialise of cooling maps

Commit 46ef9d4ed26b ("hwmon: emc2305: fixups for driver submitted to
mailing lists") missed adding the call to thermal_of_cooling_device_register
required to configure any cooling maps for the device, hence stopping it
from actually ever changing speed.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

hwmon: emc2305: Change OF properties pwm-min & pwm-max to u8

There is no DT binding for emc2305 as mainline are still
discussing how to do a generic fan binding.
The 5.15 driver was reading the "emc2305," properties
"cooling-levels", "pwm-max", "pwm-min", and "pwm-channel" as u8.
The overlay was writing them as u16 (;) so it was working.

The 6.1 driver was reading as u32, which failed as there is
insufficient data.

As this is all downstream only, revert to u8 to match 5.15.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/hwmon/emc2305.c | 95 +++++++++++++++++++++++++++++++++++++----
 1 file changed, 87 insertions(+), 8 deletions(-)

--- a/drivers/hwmon/emc2305.c
+++ b/drivers/hwmon/emc2305.c
@@ -12,12 +12,13 @@
 #include <linux/platform_data/emc2305.h>
 #include <linux/thermal.h>
 
+#define EMC2305_REG_FAN_STATUS		0x24
+#define EMC2305_REG_FAN_STALL_STATUS	0x25
 #define EMC2305_REG_DRIVE_FAIL_STATUS	0x27
 #define EMC2305_REG_VENDOR		0xfe
 #define EMC2305_FAN_MAX			0xff
 #define EMC2305_FAN_MIN			0x00
 #define EMC2305_FAN_MAX_STATE		10
-#define EMC2305_DEVICE			0x34
 #define EMC2305_VENDOR			0x5d
 #define EMC2305_REG_PRODUCT_ID		0xfd
 #define EMC2305_TACH_REGS_UNUSE_BITS	3
@@ -36,6 +37,7 @@
 #define EMC2305_RPM_FACTOR		3932160
 
 #define EMC2305_REG_FAN_DRIVE(n)	(0x30 + 0x10 * (n))
+#define EMC2305_REG_FAN_CFG(n)		(0x32 + 0x10 * (n))
 #define EMC2305_REG_FAN_MIN_DRIVE(n)	(0x38 + 0x10 * (n))
 #define EMC2305_REG_FAN_TACH(n)		(0x3e + 0x10 * (n))
 
@@ -55,6 +57,15 @@ static const struct i2c_device_id emc230
 };
 MODULE_DEVICE_TABLE(i2c, emc2305_ids);
 
+static const struct of_device_id emc2305_dt_ids[] = {
+	{ .compatible = "microchip,emc2305" },
+	{ .compatible = "microchip,emc2303" },
+	{ .compatible = "microchip,emc2302" },
+	{ .compatible = "microchip,emc2301" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, emc2305_dt_ids);
+
 /**
  * struct emc2305_cdev_data - device-specific cooling device state
  * @cdev: cooling device
@@ -100,6 +111,7 @@ struct emc2305_data {
 	u8 pwm_num;
 	bool pwm_separate;
 	u8 pwm_min[EMC2305_PWM_MAX];
+	u8 pwm_max;
 	struct emc2305_cdev_data cdev_data[EMC2305_PWM_MAX];
 };
 
@@ -272,7 +284,7 @@ static int emc2305_set_pwm(struct device
 	struct i2c_client *client = data->client;
 	int ret;
 
-	if (val < data->pwm_min[channel] || val > EMC2305_FAN_MAX)
+	if (val < data->pwm_min[channel] || val > data->pwm_max)
 		return -EINVAL;
 
 	ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(channel), val);
@@ -283,6 +295,49 @@ static int emc2305_set_pwm(struct device
 	return 0;
 }
 
+static int emc2305_get_tz_of(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct emc2305_data *data = dev_get_drvdata(dev);
+	int ret = 0;
+	u8 val;
+	int i;
+
+	/* OF parameters are optional - overwrite default setting
+	 * if some of them are provided.
+	 */
+
+	ret = of_property_read_u8(np, "emc2305,cooling-levels", &val);
+	if (!ret)
+		data->max_state = val;
+	else if (ret != -EINVAL)
+		return ret;
+
+	ret = of_property_read_u8(np, "emc2305,pwm-max", &val);
+	if (!ret)
+		data->pwm_max = val;
+	else if (ret != -EINVAL)
+		return ret;
+
+	ret = of_property_read_u8(np, "emc2305,pwm-min", &val);
+	if (!ret)
+		for (i = 0; i < EMC2305_PWM_MAX; i++)
+			data->pwm_min[i] = val;
+	else if (ret != -EINVAL)
+		return ret;
+
+	/* Not defined or 0 means one thermal zone over all cooling devices.
+	 * Otherwise - separated thermal zones for each PWM channel.
+	 */
+	ret = of_property_read_u8(np, "emc2305,pwm-channel", &val);
+	if (!ret)
+		data->pwm_separate = (val != 0);
+	else if (ret != -EINVAL)
+		return ret;
+
+	return 0;
+}
+
 static int emc2305_set_single_tz(struct device *dev, int idx)
 {
 	struct emc2305_data *data = dev_get_drvdata(dev);
@@ -292,9 +347,17 @@ static int emc2305_set_single_tz(struct
 	cdev_idx = (idx) ? idx - 1 : 0;
 	pwm = data->pwm_min[cdev_idx];
 
-	data->cdev_data[cdev_idx].cdev =
-		thermal_cooling_device_register(emc2305_fan_name[idx], data,
-						&emc2305_cooling_ops);
+	if (dev->of_node)
+		data->cdev_data[cdev_idx].cdev =
+			devm_thermal_of_cooling_device_register(dev, dev->of_node,
+								emc2305_fan_name[idx],
+								data,
+								&emc2305_cooling_ops);
+	else
+		data->cdev_data[cdev_idx].cdev =
+			thermal_cooling_device_register(emc2305_fan_name[idx],
+							data,
+							&emc2305_cooling_ops);
 
 	if (IS_ERR(data->cdev_data[cdev_idx].cdev)) {
 		dev_err(dev, "Failed to register cooling device %s\n", emc2305_fan_name[idx]);
@@ -353,9 +416,11 @@ static void emc2305_unset_tz(struct devi
 	int i;
 
 	/* Unregister cooling device. */
-	for (i = 0; i < EMC2305_PWM_MAX; i++)
-		if (data->cdev_data[i].cdev)
-			thermal_cooling_device_unregister(data->cdev_data[i].cdev);
+	if (!dev->of_node) {
+		for (i = 0; i < EMC2305_PWM_MAX; i++)
+			if (data->cdev_data[i].cdev)
+				thermal_cooling_device_unregister(data->cdev_data[i].cdev);
+	}
 }
 
 static umode_t
@@ -577,11 +642,18 @@ static int emc2305_probe(struct i2c_clie
 		data->pwm_separate = pdata->pwm_separate;
 		for (i = 0; i < EMC2305_PWM_MAX; i++)
 			data->pwm_min[i] = pdata->pwm_min[i];
+		data->pwm_max = EMC2305_FAN_MAX;
 	} else {
 		data->max_state = EMC2305_FAN_MAX_STATE;
 		data->pwm_separate = false;
 		for (i = 0; i < EMC2305_PWM_MAX; i++)
 			data->pwm_min[i] = EMC2305_FAN_MIN;
+		data->pwm_max = EMC2305_FAN_MAX;
+		if (dev->of_node) {
+			ret = emc2305_get_tz_of(dev);
+			if (ret < 0)
+				return ret;
+		}
 	}
 
 	data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "emc2305", data,
@@ -602,6 +674,12 @@ static int emc2305_probe(struct i2c_clie
 			return ret;
 	}
 
+	/* Acknowledge any existing faults. Stops the device responding on the
+	 * SMBus alert address.
+	 */
+	i2c_smbus_read_byte_data(client, EMC2305_REG_FAN_STALL_STATUS);
+	i2c_smbus_read_byte_data(client, EMC2305_REG_FAN_STATUS);
+
 	return 0;
 }
 
@@ -616,6 +694,7 @@ static void emc2305_remove(struct i2c_cl
 static struct i2c_driver emc2305_driver = {
 	.driver = {
 		.name = "emc2305",
+		.of_match_table = emc2305_dt_ids,
 	},
 	.probe = emc2305_probe,
 	.remove	  = emc2305_remove,
