Date:   Mon, 24 Jul 2017 21:37:43 +0200
From:   "Maciej S. Szmigiero" <mail@...iej.szmigiero.name>
To:     Jean Delvare <jdelvare@...e.com>,
        Guenter Roeck <linux@...ck-us.net>
Cc:     linux-hwmon@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2] hwmon: (it87) Reapply probe path chip registers settings
 after resume

After a suspend / resume cycle we possibly need to reapply chip registers
settings that we had set or fixed in a probe path, since they might have
been reset to default values or set incorrectly by a BIOS again.

Tested on a Gigabyte M720-US3 board, which requires routing internal VCCH5V
to in7 (and had it wrong again on resume from S3).

Signed-off-by: Maciej S. Szmigiero <mail@...iej.szmigiero.name>
---
Changes from v1: Move code of common probe / resume steps to new functions
so we don't need to make large parts of probe function conditional on a
newly added 'resume' parameter.

 drivers/hwmon/it87.c | 214 +++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 163 insertions(+), 51 deletions(-)

diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c
index 4dfc7238313e..b565e29c405c 100644
--- a/drivers/hwmon/it87.c
+++ b/drivers/hwmon/it87.c
@@ -497,6 +497,7 @@ static const struct it87_devices it87_devices[] = {
 #define has_vin3_5v(data)	((data)->features & FEAT_VIN3_5V)
 
 struct it87_sio_data {
+	int sioaddr;
 	enum chips type;
 	/* Values read from Super-I/O config space */
 	u8 revision;
@@ -517,6 +518,7 @@ struct it87_sio_data {
  */
 struct it87_data {
 	const struct attribute_group *groups[7];
+	int sioaddr;
 	enum chips type;
 	u32 features;
 	u8 peci_mask;
@@ -2389,10 +2391,11 @@ static const struct attribute_group it87_group_auto_pwm = {
 };
 
 /* SuperIO detection - will change isa_address if a chip is found */
-static int __init it87_find(int sioaddr, unsigned short *address,
+static int __init it87_find(unsigned short *address,
 			    struct it87_sio_data *sio_data)
 {
 	int err;
+	int sioaddr = sio_data->sioaddr;
 	u16 chip_type;
 	const char *board_vendor, *board_name;
 	const struct it87_devices *config;
@@ -2828,13 +2831,89 @@ static int __init it87_find(int sioaddr, unsigned short *address,
 	return err;
 }
 
+/*
+ * Some chips seem to have default value 0xff for all limit
+ * registers. For low voltage limits it makes no sense and triggers
+ * alarms, so change to 0 instead. For high temperature limits, it
+ * means -1 degree C, which surprisingly doesn't trigger an alarm,
+ * but is still confusing, so change to 127 degrees C.
+ */
+static void it87_check_limit_regs(struct it87_data *data)
+{
+	int i, reg;
+
+	for (i = 0; i < NUM_VIN_LIMIT; i++) {
+		reg = it87_read_value(data, IT87_REG_VIN_MIN(i));
+		if (reg == 0xff)
+			it87_write_value(data, IT87_REG_VIN_MIN(i), 0);
+	}
+	for (i = 0; i < NUM_TEMP_LIMIT; i++) {
+		reg = it87_read_value(data, IT87_REG_TEMP_HIGH(i));
+		if (reg == 0xff)
+			it87_write_value(data, IT87_REG_TEMP_HIGH(i), 127);
+	}
+}
+
+/* Check if voltage monitors are reset manually or by some reason */
+static void it87_check_voltage_monitors_reset(struct it87_data *data)
+{
+	int reg;
+
+	reg = it87_read_value(data, IT87_REG_VIN_ENABLE);
+	if ((reg & 0xff) == 0) {
+		/* Enable all voltage monitors */
+		it87_write_value(data, IT87_REG_VIN_ENABLE, 0xff);
+	}
+}
+
+/* Check if tachometers are reset manually or by some reason */
+static void it87_check_tachometers_reset(struct platform_device *pdev)
+{
+	struct it87_sio_data *sio_data = dev_get_platdata(&pdev->dev);
+	struct it87_data *data = platform_get_drvdata(pdev);
+	u8 mask, fan_main_ctrl;
+
+	mask = 0x70 & ~(sio_data->skip_fan << 4);
+	fan_main_ctrl = it87_read_value(data, IT87_REG_FAN_MAIN_CTRL);
+	if ((fan_main_ctrl & mask) == 0) {
+		/* Enable all fan tachometers */
+		fan_main_ctrl |= mask;
+		it87_write_value(data, IT87_REG_FAN_MAIN_CTRL,
+				 fan_main_ctrl);
+	}
+}
+
+/* Set tachometers to 16-bit mode if needed */
+static void it87_check_tachometers_16bit_mode(struct platform_device *pdev)
+{
+	struct it87_data *data = platform_get_drvdata(pdev);
+	int reg;
+
+	if (!has_fan16_config(data))
+		return;
+
+	reg = it87_read_value(data, IT87_REG_FAN_16BIT);
+	if (~reg & 0x07 & data->has_fan) {
+		dev_dbg(&pdev->dev,
+			"Setting fan1-3 to 16-bit mode\n");
+		it87_write_value(data, IT87_REG_FAN_16BIT,
+				 reg | 0x07);
+	}
+}
+
+static void it87_start_monitoring(struct it87_data *data)
+{
+	it87_write_value(data, IT87_REG_CONFIG,
+			 (it87_read_value(data, IT87_REG_CONFIG) & 0x3e)
+			 | (update_vbat ? 0x41 : 0x01));
+}
+
 /* Called when we have found a new IT87. */
 static void it87_init_device(struct platform_device *pdev)
 {
 	struct it87_sio_data *sio_data = dev_get_platdata(&pdev->dev);
 	struct it87_data *data = platform_get_drvdata(pdev);
 	int tmp, i;
-	u8 mask;
 
 	/*
 	 * For each PWM channel:
@@ -2855,23 +2934,7 @@ static void it87_init_device(struct platform_device *pdev)
 		data->auto_pwm[i][3] = 0x7f;	/* Full speed, hard-coded */
 	}
 
-	/*
-	 * Some chips seem to have default value 0xff for all limit
-	 * registers. For low voltage limits it makes no sense and triggers
-	 * alarms, so change to 0 instead. For high temperature limits, it
-	 * means -1 degree C, which surprisingly doesn't trigger an alarm,
-	 * but is still confusing, so change to 127 degrees C.
-	 */
-	for (i = 0; i < NUM_VIN_LIMIT; i++) {
-		tmp = it87_read_value(data, IT87_REG_VIN_MIN(i));
-		if (tmp == 0xff)
-			it87_write_value(data, IT87_REG_VIN_MIN(i), 0);
-	}
-	for (i = 0; i < NUM_TEMP_LIMIT; i++) {
-		tmp = it87_read_value(data, IT87_REG_TEMP_HIGH(i));
-		if (tmp == 0xff)
-			it87_write_value(data, IT87_REG_TEMP_HIGH(i), 127);
-	}
+	it87_check_limit_regs(data);
 
 	/*
 	 * Temperature channels are not forcibly enabled, as they can be
@@ -2880,38 +2943,19 @@ static void it87_init_device(struct platform_device *pdev)
 	 * run-time through the temp{1-3}_type sysfs accessors if needed.
 	 */
 
-	/* Check if voltage monitors are reset manually or by some reason */
-	tmp = it87_read_value(data, IT87_REG_VIN_ENABLE);
-	if ((tmp & 0xff) == 0) {
-		/* Enable all voltage monitors */
-		it87_write_value(data, IT87_REG_VIN_ENABLE, 0xff);
-	}
+	it87_check_voltage_monitors_reset(data);
+
+	it87_check_tachometers_reset(pdev);
 
-	/* Check if tachometers are reset manually or by some reason */
-	mask = 0x70 & ~(sio_data->skip_fan << 4);
 	data->fan_main_ctrl = it87_read_value(data, IT87_REG_FAN_MAIN_CTRL);
-	if ((data->fan_main_ctrl & mask) == 0) {
-		/* Enable all fan tachometers */
-		data->fan_main_ctrl |= mask;
-		it87_write_value(data, IT87_REG_FAN_MAIN_CTRL,
-				 data->fan_main_ctrl);
-	}
 	data->has_fan = (data->fan_main_ctrl >> 4) & 0x07;
 
-	tmp = it87_read_value(data, IT87_REG_FAN_16BIT);
-
-	/* Set tachometers to 16-bit mode if needed */
-	if (has_fan16_config(data)) {
-		if (~tmp & 0x07 & data->has_fan) {
-			dev_dbg(&pdev->dev,
-				"Setting fan1-3 to 16-bit mode\n");
-			it87_write_value(data, IT87_REG_FAN_16BIT,
-					 tmp | 0x07);
-		}
-	}
+	it87_check_tachometers_16bit_mode(pdev);
 
 	/* Check for additional fans */
 	if (has_five_fans(data)) {
+		tmp = it87_read_value(data, IT87_REG_FAN_16BIT);
+
 		if (tmp & BIT(4))
 			data->has_fan |= BIT(3); /* fan4 enabled */
 		if (tmp & BIT(5))
@@ -2933,10 +2977,7 @@ static void it87_init_device(struct platform_device *pdev)
 			sio_data->skip_pwm |= BIT(5);
 	}
 
-	/* Start monitoring */
-	it87_write_value(data, IT87_REG_CONFIG,
-			 (it87_read_value(data, IT87_REG_CONFIG) & 0x3e)
-			 | (update_vbat ? 0x41 : 0x01));
+	it87_start_monitoring(data);
 }
 
 /* Return 1 if and only if the PWM interface is safe to use */
@@ -2986,8 +3027,6 @@ static int it87_check_pwm(struct device *dev)
 				 "PWM configuration is too broken to be fixed\n");
 		}
 
-		dev_info(dev,
-			 "Detected broken BIOS defaults, disabling PWM interface\n");
 		return 0;
 	} else if (fix_pwm_polarity) {
 		dev_info(dev,
@@ -3020,6 +3059,7 @@ static int it87_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	data->addr = res->start;
+	data->sioaddr = sio_data->sioaddr;
 	data->type = sio_data->type;
 	data->features = it87_devices[sio_data->type].features;
 	data->peci_mask = it87_devices[sio_data->type].peci_mask;
@@ -3058,6 +3098,9 @@ static int it87_probe(struct platform_device *pdev)
 
 	/* Check PWM configuration */
 	enable_pwm_interface = it87_check_pwm(dev);
+	if (!enable_pwm_interface)
+		dev_info(dev,
+			 "Detected broken BIOS defaults, disabling PWM interface\n");
 
 	/* Starting with IT8721F, we handle scaling of internal voltages */
 	if (has_12mv_adc(data)) {
@@ -3140,9 +3183,77 @@ static int it87_probe(struct platform_device *pdev)
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }
 
+static int it87_resume_sio(struct platform_device *pdev)
+{
+	struct it87_data *data = dev_get_drvdata(&pdev->dev);
+	int err;
+	int reg2c;
+
+	if (!(data->in_internal & BIT(1)))
+		return 0;
+
+	if (has_in7_internal(data))
+		return 0;
+
+	err = superio_enter(data->sioaddr);
+	if (err)
+		return err;
+
+	superio_select(data->sioaddr, GPIO);
+
+	reg2c = superio_inb(data->sioaddr, IT87_SIO_PINX2_REG);
+	if (!(reg2c & BIT(1))) {
+		dev_notice(&pdev->dev,
+			   "Routing internal VCCH5V to in7 again");
+
+		reg2c |= BIT(1);
+		superio_outb(data->sioaddr, IT87_SIO_PINX2_REG,
+			     reg2c);
+	}
+
+	superio_exit(data->sioaddr);
+
+	return 0;
+}
+
+static int __maybe_unused it87_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct it87_data *data = dev_get_drvdata(dev);
+	int err;
+
+	err = it87_resume_sio(pdev);
+	if (err)
+		dev_err(dev,
+			"Unable to resume Super I/O (%d)",
+			err);
+
+	mutex_lock(&data->update_lock);
+
+	it87_check_pwm(dev);
+	it87_check_limit_regs(data);
+	it87_check_voltage_monitors_reset(data);
+	it87_check_tachometers_reset(pdev);
+	it87_check_tachometers_16bit_mode(pdev);
+
+	it87_start_monitoring(data);
+
+	/* force update */
+	data->valid = 0;
+
+	mutex_unlock(&data->update_lock);
+
+	it87_update_device(dev);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(it87_dev_pm_ops, NULL, it87_resume);
+
 static struct platform_driver it87_driver = {
 	.driver = {
 		.name	= DRVNAME,
+		.pm     = &it87_dev_pm_ops,
 	},
 	.probe	= it87_probe,
 };
@@ -3208,8 +3319,9 @@ static int __init sm_it87_init(void)
 
 	for (i = 0; i < ARRAY_SIZE(sioaddr); i++) {
 		memset(&sio_data, 0, sizeof(struct it87_sio_data));
+		sio_data.sioaddr = sioaddr[i];
 		isa_address[i] = 0;
-		err = it87_find(sioaddr[i], &isa_address[i], &sio_data);
+		err = it87_find(&isa_address[i], &sio_data);
 		if (err || isa_address[i] == 0)
 			continue;
 		/*

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