gpio: pca953x: Clear the polarity invert register at init

The pca953x_gpio driver uses default value of polarity inversion
register. For some devices like PCA9557 and MAX7310, their polarity
inversion register default value is 0xf0. So for high 4 ports, when
reading their values, the values are inverted as the actual level.

This patch clears the polarity inversion register to 0 at init, so
that the port read and write values are aligned.

Signed-off-by: Ye Li <ye.li@nxp.com>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Acked-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Anatolij Gustschin <agust@denx.de>

diff --git a/drivers/gpio/pca953x_gpio.c b/drivers/gpio/pca953x_gpio.c
index 0bb4844..341527a 100644 (file)
--- a/drivers/gpio/pca953x_gpio.c
+++ b/drivers/gpio/pca953x_gpio.c
@@ -130,6 +130,25 @@ static int pca953x_read_regs(struct udevice *dev, int reg, u8 *val)
        return ret;
 }
 
+static int pca953x_write_regs(struct udevice *dev, int reg, u8 *val)
+{
+       struct pca953x_info *info = dev_get_platdata(dev);
+       int ret = 0;
+
+       if (info->gpio_count <= 8) {
+               ret = dm_i2c_write(dev, reg, val, 1);
+       } else if (info->gpio_count <= 16) {
+               ret = dm_i2c_write(dev, reg << 1, val, info->bank_count);
+       } else if (info->gpio_count == 40) {
+               /* Auto increment */
+               ret = dm_i2c_write(dev, (reg << 3) | 0x80, val, info->bank_count);
+       } else {
+               return -EINVAL;
+       }
+
+       return ret;
+}
+
 static int pca953x_is_output(struct udevice *dev, int offset)
 {
        struct pca953x_info *info = dev_get_platdata(dev);
@@ -251,6 +270,7 @@ static int pca953x_probe(struct udevice *dev)
        int ret;
        int size;
        const u8 *tmp;
+       u8 val[MAX_BANK];
 
        addr = dev_read_addr(dev);
        if (addr == 0)
@@ -296,6 +316,14 @@ static int pca953x_probe(struct udevice *dev)
                snprintf(name, sizeof(name), "gpio@%x_", info->addr);
        }
 
+       /* Clear the polarity registers to no invert */
+       memset(val, 0, MAX_BANK);
+       ret = pca953x_write_regs(dev, PCA953X_INVERT, val);
+       if (ret < 0) {
+               dev_err(dev, "Error writing invert register\n");
+               return ret;
+       }
+
        str = strdup(name);
        if (!str)
                return -ENOMEM;