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Patch "pinctrl/amd: save pin registers over suspend/resume" has been added to the 4.4-stable tree

PATCH [email protected] 1 participant 2 messages Sep 21, 2017

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Stable branch Pin control Pin controller - AMD
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This is a note to let you know that I've just added the patch titled

pinctrl/amd: save pin registers over suspend/resume

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
pinctrl-amd-save-pin-registers-over-suspend-resume.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 79d2c8bede2c93f9432d7da0bc2f76a195c90fc0 Mon Sep 17 00:00:00 2001

From: Daniel Drake <[email protected]>
Date: Mon, 11 Sep 2017 14:11:56 +0800
Subject: pinctrl/amd: save pin registers over suspend/resume

From: Daniel Drake <[email protected]>

commit 79d2c8bede2c93f9432d7da0bc2f76a195c90fc0 upstream.

The touchpad in the Asus laptop models X505BA/BP and X542BA/BP is unresponsive after suspend/resume. The following error appears during resume:

i2c_hid i2c-ELAN1300:00: failed to reset device.

The problem here is that i2c_hid does not notice the interrupt being generated at this point, because the GPIO is no longer configured for interrupts.

Fix this by saving pinctrl-amd pin registers during suspend and restoring them at resume time.

Based on code from pinctrl-intel.

Signed-off-by Daniel Drake <[email protected]>
Signed-off-by Linus Walleij <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/pinctrl/pinctrl-amd.c |   75 ++++++++++++++++++++++++++++++++++++++++++
 drivers/pinctrl/pinctrl-amd.h |    1 
 2 files changed, 76 insertions(+)
drivers/pinctrl/pinctrl-amd.c +75 -0
@@ -32,6 +32,7 @@
 #include <linux/pinctrl/pinconf.h>
 #include <linux/pinctrl/pinconf-generic.h>
 
+#include "core.h"
 #include "pinctrl-utils.h"
 #include "pinctrl-amd.h"
 

@@ -708,6 +709,69 @@ static const struct pinconf_ops amd_pinc
 	.pin_config_group_set = amd_pinconf_group_set,
 };
 
+#ifdef CONFIG_PM_SLEEP
+static bool amd_gpio_should_save(struct amd_gpio *gpio_dev, unsigned int pin)
+{
+	const struct pin_desc *pd = pin_desc_get(gpio_dev->pctrl, pin);
+
+	if (!pd)
+		return false;
+
+	/*
+	 * Only restore the pin if it is actually in use by the kernel (or
+	 * by userspace).
+	 */
+	if (pd->mux_owner || pd->gpio_owner ||
+	    gpiochip_line_is_irq(&gpio_dev->gc, pin))
+		return true;
+
+	return false;
+}
+
+int amd_gpio_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct amd_gpio *gpio_dev = platform_get_drvdata(pdev);
+	struct pinctrl_desc *desc = gpio_dev->pctrl->desc;
+	int i;
+
+	for (i = 0; i < desc->npins; i++) {
+		int pin = desc->pins[i].number;
+
+		if (!amd_gpio_should_save(gpio_dev, pin))
+			continue;
+
+		gpio_dev->saved_regs[i] = readl(gpio_dev->base + pin*4);
+	}
+
+	return 0;
+}
+
+int amd_gpio_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct amd_gpio *gpio_dev = platform_get_drvdata(pdev);
+	struct pinctrl_desc *desc = gpio_dev->pctrl->desc;
+	int i;
+
+	for (i = 0; i < desc->npins; i++) {
+		int pin = desc->pins[i].number;
+
+		if (!amd_gpio_should_save(gpio_dev, pin))
+			continue;
+
+		writel(gpio_dev->saved_regs[i], gpio_dev->base + pin*4);
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops amd_gpio_pm_ops = {
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(amd_gpio_suspend,
+				     amd_gpio_resume)
+};
+#endif
+
 static struct pinctrl_desc amd_pinctrl_desc = {
 	.pins	= kerncz_pins,
 	.npins = ARRAY_SIZE(kerncz_pins),

@@ -747,6 +811,14 @@ static int amd_gpio_probe(struct platfor
 		return -EINVAL;
 	}
 
+#ifdef CONFIG_PM_SLEEP
+	gpio_dev->saved_regs = devm_kcalloc(&pdev->dev, amd_pinctrl_desc.npins,
+					    sizeof(*gpio_dev->saved_regs),
+					    GFP_KERNEL);
+	if (!gpio_dev->saved_regs)
+		return -ENOMEM;
+#endif
+
 	gpio_dev->pdev = pdev;
 	gpio_dev->gc.direction_input	= amd_gpio_direction_input;
 	gpio_dev->gc.direction_output	= amd_gpio_direction_output;

@@ -837,6 +909,9 @@ static struct platform_driver amd_gpio_d
 	.driver		= {
 		.name	= "amd_gpio",
 		.acpi_match_table = ACPI_PTR(amd_gpio_acpi_match),
+#ifdef CONFIG_PM_SLEEP
+		.pm	= &amd_gpio_pm_ops,
+#endif
 	},
 	.probe		= amd_gpio_probe,
 	.remove		= amd_gpio_remove,
drivers/pinctrl/pinctrl-amd.h +1 -0
@@ -95,6 +95,7 @@ struct amd_gpio {
 	struct gpio_chip        gc;
 	struct resource         *res;
 	struct platform_device  *pdev;
+	u32			*saved_regs;
 };
 
 /*  KERNCZ configuration*/

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/pinctrl-amd-save-pin-registers-over-suspend-resume.patch