gpio: crystalcove: support virtual GPIO

The virtual GPIO introduced in ACPI table of Baytrail-T based system is
used to solve a problem under Windows. We do not have such problems
under Linux so we do not actually need them. But we have to tell GPIO
library that the Crystal Cove GPIO chip has this many GPIO pins or the
common GPIO handler will refuse any access to those high number GPIO
pins, which will resulted in a failure evaluation of every ACPI control
method that is used to turn on/off power resource and/or report sensor
temperatures.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[changed vgpio number from 0x5e to 94]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 16 insertions, 3 deletions

diff --git a/drivers/gpio/gpio-crystalcove.c b/drivers/gpio/gpio-crystalcove.c
index e3712f0e51ab..bbfe7f508502 100644
--- a/drivers/gpio/gpio-crystalcove.c
+++ b/drivers/gpio/gpio-crystalcove.c
@@ -24,6 +24,7 @@
 #include <linux/mfd/intel_soc_pmic.h>
 
 #define CRYSTALCOVE_GPIO_NUM    16
+#define CRYSTALCOVE_VGPIO_NUM   94
 
 #define UPDATE_IRQ_TYPE         BIT(0)
 #define UPDATE_IRQ_MASK         BIT(1)
@@ -130,6 +131,9 @@ static int crystalcove_gpio_dir_in(struct gpio_chip *chip, unsigned gpio)
 {
         struct crystalcove_gpio *cg = to_cg(chip);
 
+        if (gpio > CRYSTALCOVE_VGPIO_NUM)
+                return 0;
+
         return regmap_write(cg->regmap, to_reg(gpio, CTRL_OUT),
                             CTLO_INPUT_SET);
 }
@@ -139,6 +143,9 @@ static int crystalcove_gpio_dir_out(struct gpio_chip *chip, unsigned gpio,
 {
         struct crystalcove_gpio *cg = to_cg(chip);
 
+        if (gpio > CRYSTALCOVE_VGPIO_NUM)
+                return 0;
+
         return regmap_write(cg->regmap, to_reg(gpio, CTRL_OUT),
                             CTLO_OUTPUT_SET | value);
 }
@@ -149,6 +156,9 @@ static int crystalcove_gpio_get(struct gpio_chip *chip, unsigned gpio)
         int ret;
         unsigned int val;
 
+        if (gpio > CRYSTALCOVE_VGPIO_NUM)
+                return 0;
+
         ret = regmap_read(cg->regmap, to_reg(gpio, CTRL_IN), &val);
         if (ret)
                 return ret;
@@ -161,6 +171,9 @@ static void crystalcove_gpio_set(struct gpio_chip *chip,
 {
         struct crystalcove_gpio *cg = to_cg(chip);
 
+        if (gpio > CRYSTALCOVE_VGPIO_NUM)
+                return;
+
         if (value)
                 regmap_update_bits(cg->regmap, to_reg(gpio, CTRL_OUT), 1, 1);
         else
@@ -256,7 +269,7 @@ static irqreturn_t crystalcove_gpio_irq_handler(int irq, void *data)
 
         pending = p0 | p1 << 8;
 
-        for (gpio = 0; gpio < cg->chip.ngpio; gpio++) {
+        for (gpio = 0; gpio < CRYSTALCOVE_GPIO_NUM; gpio++) {
                 if (pending & BIT(gpio)) {
                         virq = irq_find_mapping(cg->chip.irqdomain, gpio);
                         generic_handle_irq(virq);
@@ -273,7 +286,7 @@ static void crystalcove_gpio_dbg_show(struct seq_file *s,
         int gpio, offset;
         unsigned int ctlo, ctli, mirqs0, mirqsx, irq;
 
-        for (gpio = 0; gpio < cg->chip.ngpio; gpio++) {
+        for (gpio = 0; gpio < CRYSTALCOVE_GPIO_NUM; gpio++) {
                 regmap_read(cg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
                 regmap_read(cg->regmap, to_reg(gpio, CTRL_IN), &ctli);
                 regmap_read(cg->regmap, gpio < 8 ? MGPIO0IRQS0 : MGPIO1IRQS0,
@@ -320,7 +333,7 @@ static int crystalcove_gpio_probe(struct platform_device *pdev)
         cg->chip.get = crystalcove_gpio_get;
         cg->chip.set = crystalcove_gpio_set;
         cg->chip.base = -1;
-        cg->chip.ngpio = CRYSTALCOVE_GPIO_NUM;
+        cg->chip.ngpio = CRYSTALCOVE_VGPIO_NUM;
         cg->chip.can_sleep = true;
         cg->chip.dev = dev;
         cg->chip.dbg_show = crystalcove_gpio_dbg_show;