[PATCH 4.14 01/80] Revert "pinctrl: intel: Initialize GPIO properly when used through irqchip"

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Greg Kroah-Hartman <gre...@linuxfoundation.org>

This reverts commit f5a26acf0162477af6ee4c11b4fb9cffe5d3e257

Mike writes:
        It seems that commit f5a26acf0162 ("pinctrl: intel: Initialize GPIO
        properly when used through irqchip") can cause problems on some Skylake
        systems with Sunrisepoint PCH-H. Namely on certain systems it may turn
        the backlight PWM pin from native mode to GPIO which makes the screen
        blank during boot.

        There is more information here:

          https://bugzilla.redhat.com/show_bug.cgi?id=1543769

        The actual reason is that GPIO numbering used in BIOS is using "Windows"
        numbers meaning that they don't match the hardware 1:1 and because of
        this a wrong pin (backlight PWM) is picked and switched to GPIO mode.

        There is a proper fix for this but since it has quite many dependencies
        on commits that cannot be considered stable material, I suggest we
        revert commit f5a26acf0162 from stable trees 4.9, 4.14 and 4.15 to
        prevent the backlight issue.

Reported-by: Mika Westerberg <mika.westerb...@linux.intel.com>
Fixes: f5a26acf0162 ("pinctrl: intel: Initialize GPIO properly when used 
through irqchip")
Cc: Daniel Drake <dr...@endlessm.com>
Cc: Chris Chiu <c...@endlessm.com>
Cc: Linus Walleij <linus.wall...@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/pinctrl/intel/pinctrl-intel.c |   23 ++++++++---------------
 1 file changed, 8 insertions(+), 15 deletions(-)

--- a/drivers/pinctrl/intel/pinctrl-intel.c
+++ b/drivers/pinctrl/intel/pinctrl-intel.c
@@ -427,18 +427,6 @@ static void __intel_gpio_set_direction(v
        writel(value, padcfg0);
 }
 
-static void intel_gpio_set_gpio_mode(void __iomem *padcfg0)
-{
-       u32 value;
-
-       /* Put the pad into GPIO mode */
-       value = readl(padcfg0) & ~PADCFG0_PMODE_MASK;
-       /* Disable SCI/SMI/NMI generation */
-       value &= ~(PADCFG0_GPIROUTIOXAPIC | PADCFG0_GPIROUTSCI);
-       value &= ~(PADCFG0_GPIROUTSMI | PADCFG0_GPIROUTNMI);
-       writel(value, padcfg0);
-}
-
 static int intel_gpio_request_enable(struct pinctrl_dev *pctldev,
                                     struct pinctrl_gpio_range *range,
                                     unsigned pin)
@@ -446,6 +434,7 @@ static int intel_gpio_request_enable(str
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
        void __iomem *padcfg0;
        unsigned long flags;
+       u32 value;
 
        raw_spin_lock_irqsave(&pctrl->lock, flags);
 
@@ -455,7 +444,13 @@ static int intel_gpio_request_enable(str
        }
 
        padcfg0 = intel_get_padcfg(pctrl, pin, PADCFG0);
-       intel_gpio_set_gpio_mode(padcfg0);
+       /* Put the pad into GPIO mode */
+       value = readl(padcfg0) & ~PADCFG0_PMODE_MASK;
+       /* Disable SCI/SMI/NMI generation */
+       value &= ~(PADCFG0_GPIROUTIOXAPIC | PADCFG0_GPIROUTSCI);
+       value &= ~(PADCFG0_GPIROUTSMI | PADCFG0_GPIROUTNMI);
+       writel(value, padcfg0);
+
        /* Disable TX buffer and enable RX (this will be input) */
        __intel_gpio_set_direction(padcfg0, true);
 
@@ -940,8 +935,6 @@ static int intel_gpio_irq_type(struct ir
 
        raw_spin_lock_irqsave(&pctrl->lock, flags);
 
-       intel_gpio_set_gpio_mode(reg);
-
        value = readl(reg);
 
        value &= ~(PADCFG0_RXEVCFG_MASK | PADCFG0_RXINV);