linux-kernel - [PATCH v1 2/9] hwmon: (gxp_fan_ctrl) Give GPIO access to fan data

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Message-Id: <20230418152824.110823-3-nick.hawkins@hpe.com>
Date:   Tue, 18 Apr 2023 10:28:17 -0500
From:   nick.hawkins@....com
To:     verdun@....com, nick.hawkins@....com, linus.walleij@...aro.org,
        brgl@...ev.pl, robh+dt@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, jdelvare@...e.com,
        linux@...ck-us.net, linux@...linux.org.uk,
        linux-gpio@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-hwmon@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org
Subject: [PATCH v1 2/9] hwmon: (gxp_fan_ctrl) Give GPIO access to fan data

From: Nick Hawkins <nick.hawkins@....com>

The fan driver has access to the IO that reports fan presence.
Add the ability for other drivers such as GPIO to call in
to get fan information. Also remove the system power check as
the GPIO driver needs it to report power state.

Signed-off-by: Nick Hawkins <nick.hawkins@....com>
---
 drivers/hwmon/gxp-fan-ctrl.c | 58 +++++++++++++++---------------------
 1 file changed, 24 insertions(+), 34 deletions(-)

diff --git a/drivers/hwmon/gxp-fan-ctrl.c b/drivers/hwmon/gxp-fan-ctrl.c
index 0014b8b0fd41..a8fcea98cc55 100644
--- a/drivers/hwmon/gxp-fan-ctrl.c
+++ b/drivers/hwmon/gxp-fan-ctrl.c
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
-/* Copyright (C) 2022 Hewlett-Packard Enterprise Development Company, L.P. */
+/* Copyright (C) 2023 Hewlett-Packard Enterprise Development Company, L.P. */
 
 #include <linux/bits.h>
 #include <linux/err.h>
@@ -11,15 +11,14 @@
 
 #define OFS_FAN_INST	0 /* Is 0 because plreg base will be set at INST */
 #define OFS_FAN_FAIL	2 /* Is 2 bytes after base */
-#define OFS_SEVSTAT	0 /* Is 0 because fn2 base will be set at SEVSTAT */
-#define POWER_BIT	24
 
 struct gxp_fan_ctrl_drvdata {
 	void __iomem	*base;
 	void __iomem	*plreg;
-	void __iomem	*fn2;
 };
 
+struct gxp_fan_ctrl_drvdata *drvdata;
+
 static bool fan_installed(struct device *dev, int fan)
 {
 	struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);
@@ -30,6 +29,16 @@ static bool fan_installed(struct device *dev, int fan)
 	return !!(val & BIT(fan));
 }
 
+u8 get_fans_installed(void)
+{
+	static u8 val;
+
+	val = readb(drvdata->plreg + OFS_FAN_INST);
+
+	return val;
+}
+EXPORT_SYMBOL(get_fans_installed);
+
 static long fan_failed(struct device *dev, int fan)
 {
 	struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);
@@ -40,19 +49,19 @@ static long fan_failed(struct device *dev, int fan)
 	return !!(val & BIT(fan));
 }
 
-static long fan_enabled(struct device *dev, int fan)
+u8 get_fans_failed(void)
 {
-	struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);
-	u32 val;
+	static u8 val;
 
-	/*
-	 * Check the power status as if the platform is off the value
-	 * reported for the PWM will be incorrect. Report fan as
-	 * disabled.
-	 */
-	val = readl(drvdata->fn2 + OFS_SEVSTAT);
+	val = readb(drvdata->plreg + OFS_FAN_FAIL);
+
+	return val;
+}
+EXPORT_SYMBOL(get_fans_failed);
 
-	return !!((val & BIT(POWER_BIT)) && fan_installed(dev, fan));
+static long fan_enabled(struct device *dev, int fan)
+{
+	return !!(fan_installed(dev, fan));
 }
 
 static int gxp_pwm_write(struct device *dev, u32 attr, int channel, long val)
@@ -98,20 +107,8 @@ static int gxp_fan_read(struct device *dev, u32 attr, int channel, long *val)
 static int gxp_pwm_read(struct device *dev, u32 attr, int channel, long *val)
 {
 	struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);
-	u32 reg;
-
-	/*
-	 * Check the power status of the platform. If the platform is off
-	 * the value reported for the PWM will be incorrect. In this case
-	 * report a PWM of zero.
-	 */
 
-	reg = readl(drvdata->fn2 + OFS_SEVSTAT);
-
-	if (reg & BIT(POWER_BIT))
-		*val = fan_installed(dev, channel) ? readb(drvdata->base + channel) : 0;
-	else
-		*val = 0;
+	*val = fan_installed(dev, channel) ? readb(drvdata->base + channel) : 0;
 
 	return 0;
 }
@@ -198,7 +195,6 @@ static const struct hwmon_chip_info gxp_fan_ctrl_chip_info = {
 
 static int gxp_fan_ctrl_probe(struct platform_device *pdev)
 {
-	struct gxp_fan_ctrl_drvdata *drvdata;
 	struct device *dev = &pdev->dev;
 	struct device *hwmon_dev;
 
@@ -218,12 +214,6 @@ static int gxp_fan_ctrl_probe(struct platform_device *pdev)
 		return dev_err_probe(dev, PTR_ERR(drvdata->plreg),
 				     "failed to map plreg\n");
 
-	drvdata->fn2 = devm_platform_ioremap_resource_byname(pdev,
-							     "fn2");
-	if (IS_ERR(drvdata->fn2))
-		return dev_err_probe(dev, PTR_ERR(drvdata->fn2),
-				     "failed to map fn2\n");
-
 	hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
 							 "hpe_gxp_fan_ctrl",
 							 drvdata,
-- 
2.17.1