[PATCH v3 2/2] gpio: aspeed: Add support for reset tolerance

[Andrew Jeffery]

Use the new pinconf parameter for state persistence to expose the
associated capability of the Aspeed GPIO controller.

Signed-off-by: Andrew Jeffery <and...@aj.id.au>
---
 drivers/gpio/gpio-aspeed.c | 39 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-aspeed.c b/drivers/gpio/gpio-aspeed.c
index 00dc1c020198..3125dcb9211d 100644
--- a/drivers/gpio/gpio-aspeed.c
+++ b/drivers/gpio/gpio-aspeed.c
@@ -60,6 +60,7 @@ struct aspeed_gpio_bank {
        uint16_t        val_regs;
        uint16_t        irq_regs;
        uint16_t        debounce_regs;
+       uint16_t        tolerance_regs;
        const char      names[4][3];
 };
 
@@ -70,48 +71,56 @@ static const struct aspeed_gpio_bank aspeed_gpio_banks[] = {
                .val_regs = 0x0000,
                .irq_regs = 0x0008,
                .debounce_regs = 0x0040,
+               .tolerance_regs = 0x001c,
                .names = { "A", "B", "C", "D" },
        },
        {
                .val_regs = 0x0020,
                .irq_regs = 0x0028,
                .debounce_regs = 0x0048,
+               .tolerance_regs = 0x003c,
                .names = { "E", "F", "G", "H" },
        },
        {
                .val_regs = 0x0070,
                .irq_regs = 0x0098,
                .debounce_regs = 0x00b0,
+               .tolerance_regs = 0x00ac,
                .names = { "I", "J", "K", "L" },
        },
        {
                .val_regs = 0x0078,
                .irq_regs = 0x00e8,
                .debounce_regs = 0x0100,
+               .tolerance_regs = 0x00fc,
                .names = { "M", "N", "O", "P" },
        },
        {
                .val_regs = 0x0080,
                .irq_regs = 0x0118,
                .debounce_regs = 0x0130,
+               .tolerance_regs = 0x012c,
                .names = { "Q", "R", "S", "T" },
        },
        {
                .val_regs = 0x0088,
                .irq_regs = 0x0148,
                .debounce_regs = 0x0160,
+               .tolerance_regs = 0x015c,
                .names = { "U", "V", "W", "X" },
        },
        {
                .val_regs = 0x01E0,
                .irq_regs = 0x0178,
                .debounce_regs = 0x0190,
+               .tolerance_regs = 0x018c,
                .names = { "Y", "Z", "AA", "AB" },
        },
        {
-               .val_regs = 0x01E8,
-               .irq_regs = 0x01A8,
+               .val_regs = 0x01e8,
+               .irq_regs = 0x01a8,
                .debounce_regs = 0x01c0,
+               .tolerance_regs = 0x01bc,
                .names = { "AC", "", "", "" },
        },
 };
@@ -534,6 +543,30 @@ static int aspeed_gpio_setup_irqs(struct aspeed_gpio *gpio,
        return 0;
 }
 
+static int aspeed_gpio_reset_tolerance(struct gpio_chip *chip,
+                                       unsigned int offset, bool enable)
+{
+       struct aspeed_gpio *gpio = gpiochip_get_data(chip);
+       const struct aspeed_gpio_bank *bank;
+       unsigned long flags;
+       u32 val;
+
+       bank = to_bank(offset);
+
+       spin_lock_irqsave(&gpio->lock, flags);
+       val = readl(gpio->base + bank->tolerance_regs);
+
+       if (enable)
+               val |= GPIO_BIT(offset);
+       else
+               val &= ~GPIO_BIT(offset);
+
+       writel(val, gpio->base + bank->tolerance_regs);
+       spin_unlock_irqrestore(&gpio->lock, flags);
+
+       return 0;
+}
+
 static int aspeed_gpio_request(struct gpio_chip *chip, unsigned int offset)
 {
        if (!have_gpio(gpiochip_get_data(chip), offset))
@@ -771,6 +804,8 @@ static int aspeed_gpio_set_config(struct gpio_chip *chip, 
unsigned int offset,
                        param == PIN_CONFIG_DRIVE_OPEN_SOURCE)
                /* Return -ENOTSUPP to trigger emulation, as per datasheet */
                return -ENOTSUPP;
+       else if (param == PIN_CONFIG_PERSIST_STATE)
+               return aspeed_gpio_reset_tolerance(chip, offset, arg);
 
        return -ENOTSUPP;
 }
-- 
2.11.0