drivers/macintosh/windfarm_ad7417_sensor.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Windfarm PowerMac thermal control. AD7417 sensors
  *
  * Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
  */

 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/wait.h>
 #include <linux/i2c.h>
 #include <asm/prom.h>
 #include <asm/machdep.h>
 #include <asm/io.h>
 #include <asm/sections.h>

 #include "windfarm.h"
 #include "windfarm_mpu.h"

 #define VERSION "1.0"

 struct wf_ad7417_priv {
 	struct kref		ref;
 	struct i2c_client	*i2c;
 	u8			config;
 	u8			cpu;
 	const struct mpu_data	*mpu;
 	struct wf_sensor	sensors[5];
 	struct mutex		lock;
 };

 static int wf_ad7417_temp_get(struct wf_sensor *sr, s32 *value)
 {
 	struct wf_ad7417_priv *pv = sr->priv;
 	u8 buf[2];
 	s16 raw;
 	int rc;

 	*value = 0;
 	mutex_lock(&pv->lock);

 	/* Read temp register */
 	buf[0] = 0;
 	rc = i2c_master_send(pv->i2c, buf, 1);
 	if (rc < 0)
 		goto error;
 	rc = i2c_master_recv(pv->i2c, buf, 2);
 	if (rc < 0)
 		goto error;

 	/* Read a a 16-bit signed value */
 	raw = be16_to_cpup((__le16 *)buf);

 	/* Convert 8.8-bit to 16.16 fixed point */
 	*value = ((s32)raw) << 8;

 	mutex_unlock(&pv->lock);
 	return 0;

 error:
 	mutex_unlock(&pv->lock);
 	return -1;
 }

 /*
  * Scaling factors for the AD7417 ADC converters (except
  * for the CPU diode which is obtained from the EEPROM).
  * Those values are obtained from the property list of
  * the darwin driver
  */
 #define ADC_12V_CURRENT_SCALE	0x0320	/* _AD2 */
 #define ADC_CPU_VOLTAGE_SCALE	0x00a0	/* _AD3 */
 #define ADC_CPU_CURRENT_SCALE	0x1f40	/* _AD4 */

 static void wf_ad7417_adc_convert(struct wf_ad7417_priv *pv,
 				  int chan, s32 raw, s32 *value)
 {
 	switch(chan) {
 	case 1: /* Diode */
 		*value = (raw * (s32)pv->mpu->mdiode +
 			((s32)pv->mpu->bdiode << 12)) >> 2;
 		break;
 	case 2: /* 12v current */
 		*value = raw * ADC_12V_CURRENT_SCALE;
 		break;
 	case 3: /* core voltage */
 		*value = raw * ADC_CPU_VOLTAGE_SCALE;
 		break;
 	case 4: /* core current */
 		*value = raw * ADC_CPU_CURRENT_SCALE;
 		break;
 	}
 }

 static int wf_ad7417_adc_get(struct wf_sensor *sr, s32 *value)
 {
 	struct wf_ad7417_priv *pv = sr->priv;
 	int chan = sr - pv->sensors;
 	int i, rc;
 	u8 buf[2];
 	u16 raw;

 	*value = 0;
 	mutex_lock(&pv->lock);
 	for (i = 0; i < 10; i++) {
 		/* Set channel */
 		buf[0] = 1;
 		buf[1] = (pv->config & 0x1f) | (chan << 5);
 		rc = i2c_master_send(pv->i2c, buf, 2);
 		if (rc < 0)
 			goto error;

 		/* Wait for conversion */
 		msleep(1);

 		/* Switch to data register */
 		buf[0] = 4;
 		rc = i2c_master_send(pv->i2c, buf, 1);
 		if (rc < 0)
 			goto error;

 		/* Read result */
 		rc = i2c_master_recv(pv->i2c, buf, 2);
 		if (rc < 0)
 			goto error;

 		/* Read a a 16-bit signed value */
 		raw = be16_to_cpup((__le16 *)buf) >> 6;
 		wf_ad7417_adc_convert(pv, chan, raw, value);

 		dev_vdbg(&pv->i2c->dev, "ADC chan %d [%s]"
 			 " raw value: 0x%x, conv to: 0x%08x\n",
 			 chan, sr->name, raw, *value);

 		mutex_unlock(&pv->lock);
 		return 0;

 	error:
 		dev_dbg(&pv->i2c->dev,
 			  "Error reading ADC, try %d...\n", i);
 		if (i < 9)
 			msleep(10);
 	}
 	mutex_unlock(&pv->lock);
 	return -1;
 }

 static void wf_ad7417_release(struct kref *ref)
 {
 	struct wf_ad7417_priv *pv = container_of(ref,
 						 struct wf_ad7417_priv, ref);
 	kfree(pv);
 }

 static void wf_ad7417_sensor_release(struct wf_sensor *sr)
 {
 	struct wf_ad7417_priv *pv = sr->priv;

 	kfree(sr->name);
 	kref_put(&pv->ref, wf_ad7417_release);
 }

 static const struct wf_sensor_ops wf_ad7417_temp_ops = {
 	.get_value	= wf_ad7417_temp_get,
 	.release	= wf_ad7417_sensor_release,
 	.owner		= THIS_MODULE,
 };

 static const struct wf_sensor_ops wf_ad7417_adc_ops = {
 	.get_value	= wf_ad7417_adc_get,
 	.release	= wf_ad7417_sensor_release,
 	.owner		= THIS_MODULE,
 };

 static void wf_ad7417_add_sensor(struct wf_ad7417_priv *pv,
 				 int index, const char *name,
 				 const struct wf_sensor_ops *ops)
 {
 	pv->sensors[index].name = kasprintf(GFP_KERNEL, "%s-%d", name, pv->cpu);
 	pv->sensors[index].priv = pv;
 	pv->sensors[index].ops = ops;
 	if (!wf_register_sensor(&pv->sensors[index]))
 		kref_get(&pv->ref);
 }

 static void wf_ad7417_init_chip(struct wf_ad7417_priv *pv)
 {
 	int rc;
 	u8 buf[2];
 	u8 config = 0;

 	/*
 	 * Read ADC the configuration register and cache it. We
 	 * also make sure Config2 contains proper values, I've seen
 	 * cases where we got stale grabage in there, thus preventing
 	 * proper reading of conv. values
 	 */

 	/* Clear Config2 */
 	buf[0] = 5;
 	buf[1] = 0;
 	i2c_master_send(pv->i2c, buf, 2);

 	/* Read & cache Config1 */
 	buf[0] = 1;
 	rc = i2c_master_send(pv->i2c, buf, 1);
 	if (rc > 0) {
 		rc = i2c_master_recv(pv->i2c, buf, 1);
 		if (rc > 0) {
 			config = buf[0];

 			dev_dbg(&pv->i2c->dev, "ADC config reg: %02x\n",
 				config);

 			/* Disable shutdown mode */
 			config &= 0xfe;
 			buf[0] = 1;
 			buf[1] = config;
 			rc = i2c_master_send(pv->i2c, buf, 2);
 		}
 	}
 	if (rc <= 0)
 		dev_err(&pv->i2c->dev, "Error reading ADC config\n");

 	pv->config = config;
 }

 static int wf_ad7417_probe(struct i2c_client *client,
 			   const struct i2c_device_id *id)
 {
 	struct wf_ad7417_priv *pv;
 	const struct mpu_data *mpu;
 	const char *loc;
 	int cpu_nr;

 	loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
 	if (!loc) {
 		dev_warn(&client->dev, "Missing hwsensor-location property!\n");
 		return -ENXIO;
 	}

 	/*
 	 * Identify which CPU we belong to by looking at the first entry
 	 * in the hwsensor-location list
 	 */
 	if (!strncmp(loc, "CPU A", 5))
 		cpu_nr = 0;
 	else if (!strncmp(loc, "CPU B", 5))
 		cpu_nr = 1;
 	else {
 		pr_err("wf_ad7417: Can't identify location %s\n", loc);
 		return -ENXIO;
 	}
 	mpu = wf_get_mpu(cpu_nr);
 	if (!mpu) {
 		dev_err(&client->dev, "Failed to retrieve MPU data\n");
 		return -ENXIO;
 	}

 	pv = kzalloc(sizeof(struct wf_ad7417_priv), GFP_KERNEL);
 	if (pv == NULL)
 		return -ENODEV;

 	kref_init(&pv->ref);
 	mutex_init(&pv->lock);
 	pv->i2c = client;
 	pv->cpu = cpu_nr;
 	pv->mpu = mpu;
 	dev_set_drvdata(&client->dev, pv);

 	/* Initialize the chip */
 	wf_ad7417_init_chip(pv);

 	/*
 	 * We cannot rely on Apple device-tree giving us child
 	 * node with the names of the individual sensors so we
 	 * just hard code what we know about them
 	 */
 	wf_ad7417_add_sensor(pv, 0, "cpu-amb-temp", &wf_ad7417_temp_ops);
 	wf_ad7417_add_sensor(pv, 1, "cpu-diode-temp", &wf_ad7417_adc_ops);
 	wf_ad7417_add_sensor(pv, 2, "cpu-12v-current", &wf_ad7417_adc_ops);
 	wf_ad7417_add_sensor(pv, 3, "cpu-voltage", &wf_ad7417_adc_ops);
 	wf_ad7417_add_sensor(pv, 4, "cpu-current", &wf_ad7417_adc_ops);

 	return 0;
 }

 static int wf_ad7417_remove(struct i2c_client *client)
 {
 	struct wf_ad7417_priv *pv = dev_get_drvdata(&client->dev);
 	int i;

 	/* Mark client detached */
 	pv->i2c = NULL;

 	/* Release sensor */
 	for (i = 0; i < 5; i++)
 		wf_unregister_sensor(&pv->sensors[i]);

 	kref_put(&pv->ref, wf_ad7417_release);

 	return 0;
 }

 static const struct i2c_device_id wf_ad7417_id[] = {
 	{ "MAC,ad7417", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, wf_ad7417_id);

 static struct i2c_driver wf_ad7417_driver = {
 	.driver = {
 		.name	= "wf_ad7417",
 	},
 	.probe		= wf_ad7417_probe,
 	.remove		= wf_ad7417_remove,
 	.id_table	= wf_ad7417_id,
 };

 static int wf_ad7417_init(void)
 {
 	/* This is only supported on these machines */
 	if (!of_machine_is_compatible("PowerMac7,2") &&
 	    !of_machine_is_compatible("PowerMac7,3") &&
 	    !of_machine_is_compatible("RackMac3,1"))
 		return -ENODEV;

 	return i2c_add_driver(&wf_ad7417_driver);
 }

 static void wf_ad7417_exit(void)
 {
 	i2c_del_driver(&wf_ad7417_driver);
 }

 module_init(wf_ad7417_init);
 module_exit(wf_ad7417_exit);

 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 MODULE_DESCRIPTION("ad7417 sensor driver for PowerMacs");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Windfarm PowerMac thermal control. AD7417 sensors
	*
	* Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
	*/

	#include <linux/types.h>
	#include <linux/errno.h>
	#include <linux/kernel.h>
	#include <linux/delay.h>
	#include <linux/slab.h>
	#include <linux/init.h>
	#include <linux/wait.h>
	#include <linux/i2c.h>
	#include <asm/prom.h>
	#include <asm/machdep.h>
	#include <asm/io.h>
	#include <asm/sections.h>

	#include "windfarm.h"
	#include "windfarm_mpu.h"

	#define VERSION "1.0"

	struct wf_ad7417_priv {
	struct kref ref;
	struct i2c_client *i2c;
	u8 config;
	u8 cpu;
	const struct mpu_data *mpu;
	struct wf_sensor sensors[5];
	struct mutex lock;
	};

	static int wf_ad7417_temp_get(struct wf_sensor sr, s32 value)
	{
	struct wf_ad7417_priv *pv = sr->priv;
	u8 buf[2];
	s16 raw;
	int rc;

	*value = 0;
	mutex_lock(&pv->lock);

	/* Read temp register */
	buf[0] = 0;
	rc = i2c_master_send(pv->i2c, buf, 1);
	if (rc < 0)
	goto error;
	rc = i2c_master_recv(pv->i2c, buf, 2);
	if (rc < 0)
	goto error;

	/* Read a a 16-bit signed value */
	raw = be16_to_cpup((__le16 *)buf);

	/* Convert 8.8-bit to 16.16 fixed point */
	*value = ((s32)raw) << 8;

	mutex_unlock(&pv->lock);
	return 0;

	error:
	mutex_unlock(&pv->lock);
	return -1;
	}

	/*
	* Scaling factors for the AD7417 ADC converters (except
	* for the CPU diode which is obtained from the EEPROM).
	* Those values are obtained from the property list of
	* the darwin driver
	*/
	#define ADC_12V_CURRENT_SCALE 0x0320 /* _AD2 */
	#define ADC_CPU_VOLTAGE_SCALE 0x00a0 /* _AD3 */
	#define ADC_CPU_CURRENT_SCALE 0x1f40 /* _AD4 */

	static void wf_ad7417_adc_convert(struct wf_ad7417_priv *pv,
	int chan, s32 raw, s32 *value)
	{
	switch(chan) {
	case 1: /* Diode */
	value = (raw (s32)pv->mpu->mdiode +
	((s32)pv->mpu->bdiode << 12)) >> 2;
	break;
	case 2: /* 12v current */
	value = raw ADC_12V_CURRENT_SCALE;
	break;
	case 3: /* core voltage */
	value = raw ADC_CPU_VOLTAGE_SCALE;
	break;
	case 4: /* core current */
	value = raw ADC_CPU_CURRENT_SCALE;
	break;
	}
	}

	static int wf_ad7417_adc_get(struct wf_sensor sr, s32 value)
	{
	struct wf_ad7417_priv *pv = sr->priv;
	int chan = sr - pv->sensors;
	int i, rc;
	u8 buf[2];
	u16 raw;

	*value = 0;
	mutex_lock(&pv->lock);
	for (i = 0; i < 10; i++) {
	/* Set channel */
	buf[0] = 1;
	buf[1] = (pv->config & 0x1f) \| (chan << 5);
	rc = i2c_master_send(pv->i2c, buf, 2);
	if (rc < 0)
	goto error;

	/* Wait for conversion */
	msleep(1);

	/* Switch to data register */
	buf[0] = 4;
	rc = i2c_master_send(pv->i2c, buf, 1);
	if (rc < 0)
	goto error;

	/* Read result */
	rc = i2c_master_recv(pv->i2c, buf, 2);
	if (rc < 0)
	goto error;

	/* Read a a 16-bit signed value */
	raw = be16_to_cpup((__le16 *)buf) >> 6;
	wf_ad7417_adc_convert(pv, chan, raw, value);

	dev_vdbg(&pv->i2c->dev, "ADC chan %d [%s]"
	" raw value: 0x%x, conv to: 0x%08x\n",
	chan, sr->name, raw, *value);

	mutex_unlock(&pv->lock);
	return 0;

	error:
	dev_dbg(&pv->i2c->dev,
	"Error reading ADC, try %d...\n", i);
	if (i < 9)
	msleep(10);
	}
	mutex_unlock(&pv->lock);
	return -1;
	}

	static void wf_ad7417_release(struct kref *ref)
	{
	struct wf_ad7417_priv *pv = container_of(ref,
	struct wf_ad7417_priv, ref);
	kfree(pv);
	}

	static void wf_ad7417_sensor_release(struct wf_sensor *sr)
	{
	struct wf_ad7417_priv *pv = sr->priv;

	kfree(sr->name);
	kref_put(&pv->ref, wf_ad7417_release);
	}

	static const struct wf_sensor_ops wf_ad7417_temp_ops = {
	.get_value = wf_ad7417_temp_get,
	.release = wf_ad7417_sensor_release,
	.owner = THIS_MODULE,
	};

	static const struct wf_sensor_ops wf_ad7417_adc_ops = {
	.get_value = wf_ad7417_adc_get,
	.release = wf_ad7417_sensor_release,
	.owner = THIS_MODULE,
	};

	static void wf_ad7417_add_sensor(struct wf_ad7417_priv *pv,
	int index, const char *name,
	const struct wf_sensor_ops *ops)
	{
	pv->sensors[index].name = kasprintf(GFP_KERNEL, "%s-%d", name, pv->cpu);
	pv->sensors[index].priv = pv;
	pv->sensors[index].ops = ops;
	if (!wf_register_sensor(&pv->sensors[index]))
	kref_get(&pv->ref);
	}

	static void wf_ad7417_init_chip(struct wf_ad7417_priv *pv)
	{
	int rc;
	u8 buf[2];
	u8 config = 0;

	/*
	* Read ADC the configuration register and cache it. We
	* also make sure Config2 contains proper values, I've seen
	* cases where we got stale grabage in there, thus preventing
	* proper reading of conv. values
	*/

	/* Clear Config2 */
	buf[0] = 5;
	buf[1] = 0;
	i2c_master_send(pv->i2c, buf, 2);

	/* Read & cache Config1 */
	buf[0] = 1;
	rc = i2c_master_send(pv->i2c, buf, 1);
	if (rc > 0) {
	rc = i2c_master_recv(pv->i2c, buf, 1);
	if (rc > 0) {
	config = buf[0];

	dev_dbg(&pv->i2c->dev, "ADC config reg: %02x\n",
	config);

	/* Disable shutdown mode */
	config &= 0xfe;
	buf[0] = 1;
	buf[1] = config;
	rc = i2c_master_send(pv->i2c, buf, 2);
	}
	}
	if (rc <= 0)
	dev_err(&pv->i2c->dev, "Error reading ADC config\n");

	pv->config = config;
	}

	static int wf_ad7417_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct wf_ad7417_priv *pv;
	const struct mpu_data *mpu;
	const char *loc;
	int cpu_nr;

	loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
	if (!loc) {
	dev_warn(&client->dev, "Missing hwsensor-location property!\n");
	return -ENXIO;
	}

	/*
	* Identify which CPU we belong to by looking at the first entry
	* in the hwsensor-location list
	*/
	if (!strncmp(loc, "CPU A", 5))
	cpu_nr = 0;
	else if (!strncmp(loc, "CPU B", 5))
	cpu_nr = 1;
	else {
	pr_err("wf_ad7417: Can't identify location %s\n", loc);
	return -ENXIO;
	}
	mpu = wf_get_mpu(cpu_nr);
	if (!mpu) {
	dev_err(&client->dev, "Failed to retrieve MPU data\n");
	return -ENXIO;
	}

	pv = kzalloc(sizeof(struct wf_ad7417_priv), GFP_KERNEL);
	if (pv == NULL)
	return -ENODEV;

	kref_init(&pv->ref);
	mutex_init(&pv->lock);
	pv->i2c = client;
	pv->cpu = cpu_nr;
	pv->mpu = mpu;
	dev_set_drvdata(&client->dev, pv);

	/* Initialize the chip */
	wf_ad7417_init_chip(pv);

	/*
	* We cannot rely on Apple device-tree giving us child
	* node with the names of the individual sensors so we
	* just hard code what we know about them
	*/
	wf_ad7417_add_sensor(pv, 0, "cpu-amb-temp", &wf_ad7417_temp_ops);
	wf_ad7417_add_sensor(pv, 1, "cpu-diode-temp", &wf_ad7417_adc_ops);
	wf_ad7417_add_sensor(pv, 2, "cpu-12v-current", &wf_ad7417_adc_ops);
	wf_ad7417_add_sensor(pv, 3, "cpu-voltage", &wf_ad7417_adc_ops);
	wf_ad7417_add_sensor(pv, 4, "cpu-current", &wf_ad7417_adc_ops);

	return 0;
	}

	static int wf_ad7417_remove(struct i2c_client *client)
	{
	struct wf_ad7417_priv *pv = dev_get_drvdata(&client->dev);
	int i;

	/* Mark client detached */
	pv->i2c = NULL;

	/* Release sensor */
	for (i = 0; i < 5; i++)
	wf_unregister_sensor(&pv->sensors[i]);

	kref_put(&pv->ref, wf_ad7417_release);

	return 0;
	}

	static const struct i2c_device_id wf_ad7417_id[] = {
	{ "MAC,ad7417", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, wf_ad7417_id);

	static struct i2c_driver wf_ad7417_driver = {
	.driver = {
	.name = "wf_ad7417",
	},
	.probe = wf_ad7417_probe,
	.remove = wf_ad7417_remove,
	.id_table = wf_ad7417_id,
	};

	static int wf_ad7417_init(void)
	{
	/* This is only supported on these machines */
	if (!of_machine_is_compatible("PowerMac7,2") &&
	!of_machine_is_compatible("PowerMac7,3") &&
	!of_machine_is_compatible("RackMac3,1"))
	return -ENODEV;

	return i2c_add_driver(&wf_ad7417_driver);
	}

	static void wf_ad7417_exit(void)
	{
	i2c_del_driver(&wf_ad7417_driver);
	}

	module_init(wf_ad7417_init);
	module_exit(wf_ad7417_exit);

	MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
	MODULE_DESCRIPTION("ad7417 sensor driver for PowerMacs");
	MODULE_LICENSE("GPL");