gpio: xilinx: Not read output values via regs

Reading registers for finding out output value is not working because
input value is read instead in case of tristate.

Reported-by: Stefan Herbrechtsmeier <stefan@herbrechtsmeier.net>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Stefan Herbrechtsmeier <stefan@herbrechtsmeier.net>

diff --git a/drivers/gpio/xilinx_gpio.c b/drivers/gpio/xilinx_gpio.c
index cccfa75617395ce299a69c563316f4847960584f..2fb1fe348e39d340e75e7b9575756059d45958e6 100644 (file)
--- a/drivers/gpio/xilinx_gpio.c
+++ b/drivers/gpio/xilinx_gpio.c
@@ -25,6 +25,11 @@ struct xilinx_gpio_platdata {
        int bank_max[XILINX_GPIO_MAX_BANK];
        int bank_input[XILINX_GPIO_MAX_BANK];
        int bank_output[XILINX_GPIO_MAX_BANK];
+       u32 dout_default[XILINX_GPIO_MAX_BANK];
+};
+
+struct xilinx_gpio_privdata {
+       u32 output_val[XILINX_GPIO_MAX_BANK];
 };
 
 static int xilinx_gpio_get_bank_pin(unsigned offset, u32 *bank_num,
@@ -54,6 +59,7 @@ static int xilinx_gpio_set_value(struct udevice *dev, unsigned offset,
                                 int value)
 {
        struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev);
+       struct xilinx_gpio_privdata *priv = dev_get_priv(dev);
        int val, ret;
        u32 bank, pin;
 
@@ -61,10 +67,10 @@ static int xilinx_gpio_set_value(struct udevice *dev, unsigned offset,
        if (ret)
                return ret;
 
-       val = readl(&platdata->regs->gpiodata + bank * 2);
+       val = priv->output_val[bank];
 
-       debug("%s: regs: %lx, value: %x, gpio: %x, bank %x, pin %x\n",
-             __func__, (ulong)platdata->regs, value, offset, bank, pin);
+       debug("%s: regs: %lx, value: %x, gpio: %x, bank %x, pin %x, out %x\n",
+             __func__, (ulong)platdata->regs, value, offset, bank, pin, val);
 
        if (value)
                val = val | (1 << pin);
@@ -73,12 +79,15 @@ static int xilinx_gpio_set_value(struct udevice *dev, unsigned offset,
 
        writel(val, &platdata->regs->gpiodata + bank * 2);
 
+       priv->output_val[bank] = val;
+
        return val;
 };
 
 static int xilinx_gpio_get_value(struct udevice *dev, unsigned offset)
 {
        struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev);
+       struct xilinx_gpio_privdata *priv = dev_get_priv(dev);
        int val, ret;
        u32 bank, pin;
 
@@ -89,7 +98,14 @@ static int xilinx_gpio_get_value(struct udevice *dev, unsigned offset)
        debug("%s: regs: %lx, gpio: %x, bank %x, pin %x\n", __func__,
              (ulong)platdata->regs, offset, bank, pin);
 
-       val = readl(&platdata->regs->gpiodata + bank * 2);
+       if (platdata->bank_output[bank]) {
+               debug("%s: Read saved output value\n", __func__);
+               val = priv->output_val[bank];
+       } else {
+               debug("%s: Read input value from reg\n", __func__);
+               val = readl(&platdata->regs->gpiodata + bank * 2);
+       }
+
        val = !!(val & (1 << pin));
 
        return val;
@@ -223,12 +239,18 @@ static const struct dm_gpio_ops xilinx_gpio_ops = {
 static int xilinx_gpio_probe(struct udevice *dev)
 {
        struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev);
+       struct xilinx_gpio_privdata *priv = dev_get_priv(dev);
        struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
 
        uc_priv->bank_name = dev->name;
 
        uc_priv->gpio_count = platdata->bank_max[0] + platdata->bank_max[1];
 
+       priv->output_val[0] = platdata->dout_default[0];
+
+       if (platdata->bank_max[1])
+               priv->output_val[1] = platdata->dout_default[1];
+
        return 0;
 }
 
@@ -245,6 +267,9 @@ static int xilinx_gpio_ofdata_to_platdata(struct udevice *dev)
                                                       "xlnx,all-inputs", 0);
        platdata->bank_output[0] = dev_read_u32_default(dev,
                                                        "xlnx,all-outputs", 0);
+       platdata->dout_default[0] = dev_read_u32_default(dev,
+                                                        "xlnx,dout-default",
+                                                        0);
 
        is_dual = dev_read_u32_default(dev, "xlnx,is-dual", 0);
        if (is_dual) {
@@ -254,6 +279,8 @@ static int xilinx_gpio_ofdata_to_platdata(struct udevice *dev)
                                                "xlnx,all-inputs-2", 0);
                platdata->bank_output[1] = dev_read_u32_default(dev,
                                                "xlnx,all-outputs-2", 0);
+               platdata->dout_default[1] = dev_read_u32_default(dev,
+                                               "xlnx,dout-default-2", 0);
        }
 
        return 0;
@@ -272,4 +299,5 @@ U_BOOT_DRIVER(xilinx_gpio) = {
        .ofdata_to_platdata = xilinx_gpio_ofdata_to_platdata,
        .probe = xilinx_gpio_probe,
        .platdata_auto_alloc_size = sizeof(struct xilinx_gpio_platdata),
+       .priv_auto_alloc_size = sizeof(struct xilinx_gpio_privdata),
 };