pinctrl: intel: Retain HOSTSW_OWN for requested gpio pin

The touchpad of the ASUS laptops E403NA, X540NA, X541NA are not
responsive after suspend/resume. The following error message
shows after resume.
 i2c_hid i2c-ELAN1200:00: failed to reset device.

On these laptops, the touchpad interrupt is connected via a GPIO
pin which is controlled by Intel pinctrl. After system resumes,
the GPIO is in ACPI mode and no longer works as an IRQ.

This commit saves the HOSTSW_OWN value during suspend, make sure
the HOSTSW_OWN mode remains the same after resume.

Signed-off-by: Chris Chiu <chiu@endlessm.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

diff --git a/drivers/pinctrl/intel/pinctrl-intel.c b/drivers/pinctrl/intel/pinctrl-intel.c
index 70638b74f9d67de26232f3095887f7aa7e8f0cea..1c85cc807a8ff1e716a34634d23ad9d00dca018e 100644 (file)
--- a/drivers/pinctrl/intel/pinctrl-intel.c
+++ b/drivers/pinctrl/intel/pinctrl-intel.c
@@ -81,6 +81,7 @@ struct intel_pad_context {
 
 struct intel_community_context {
        u32 *intmask;
+       u32 *hostown;
 };
 
 struct intel_pinctrl_context {
@@ -1284,7 +1285,7 @@ static int intel_pinctrl_pm_init(struct intel_pinctrl *pctrl)
 
        for (i = 0; i < pctrl->ncommunities; i++) {
                struct intel_community *community = &pctrl->communities[i];
-               u32 *intmask;
+               u32 *intmask, *hostown;
 
                intmask = devm_kcalloc(pctrl->dev, community->ngpps,
                                       sizeof(*intmask), GFP_KERNEL);
@@ -1292,6 +1293,13 @@ static int intel_pinctrl_pm_init(struct intel_pinctrl *pctrl)
                        return -ENOMEM;
 
                communities[i].intmask = intmask;
+
+               hostown = devm_kcalloc(pctrl->dev, community->ngpps,
+                                      sizeof(*hostown), GFP_KERNEL);
+               if (!hostown)
+                       return -ENOMEM;
+
+               communities[i].hostown = hostown;
        }
 
        pctrl->context.pads = pads;
@@ -1501,6 +1509,10 @@ int intel_pinctrl_suspend_noirq(struct device *dev)
                base = community->regs + community->ie_offset;
                for (gpp = 0; gpp < community->ngpps; gpp++)
                        communities[i].intmask[gpp] = readl(base + gpp * 4);
+
+               base = community->regs + community->hostown_offset;
+               for (gpp = 0; gpp < community->ngpps; gpp++)
+                       communities[i].hostown[gpp] = readl(base + gpp * 4);
        }
 
        return 0;
@@ -1527,6 +1539,29 @@ static void intel_gpio_irq_init(struct intel_pinctrl *pctrl)
        }
 }
 
+static u32
+intel_gpio_is_requested(struct gpio_chip *chip, int base, unsigned int size)
+{
+       u32 requested = 0;
+       unsigned int i;
+
+       for (i = 0; i < size; i++)
+               if (gpiochip_is_requested(chip, base + i))
+                       requested |= BIT(i);
+
+       return requested;
+}
+
+static u32
+intel_gpio_update_pad_mode(void __iomem *hostown, u32 mask, u32 value)
+{
+       u32 curr = readl(hostown);
+       u32 updated = (curr & ~mask) | (value & mask);
+
+       writel(updated, hostown);
+       return curr;
+}
+
 int intel_pinctrl_resume_noirq(struct device *dev)
 {
        struct intel_pinctrl *pctrl = dev_get_drvdata(dev);
@@ -1585,6 +1620,25 @@ int intel_pinctrl_resume_noirq(struct device *dev)
                        dev_dbg(dev, "restored mask %d/%u %#08x\n", i, gpp,
                                readl(base + gpp * 4));
                }
+
+               base = community->regs + community->hostown_offset;
+               for (gpp = 0; gpp < community->ngpps; gpp++) {
+                       const struct intel_padgroup *padgrp = &community->gpps[gpp];
+                       u32 requested = 0, value = 0;
+                       u32 saved = communities[i].hostown[gpp];
+
+                       if (padgrp->gpio_base < 0)
+                               continue;
+
+                       requested = intel_gpio_is_requested(&pctrl->chip,
+                                       padgrp->gpio_base, padgrp->size);
+                       value = intel_gpio_update_pad_mode(base + gpp * 4,
+                                       requested, saved);
+                       if ((value ^ saved) & requested) {
+                               dev_warn(dev, "restore hostown %d/%u %#8x->%#8x\n",
+                                       i, gpp, value, saved);
+                       }
+               }
        }
 
        return 0;