When initialising the driver, check if the RTL8231 chip is actually
present at the specified address. If the READY_CODE value does not match
the expected value, return -ENXIO to fail probing.
This should help users to figure out which address an RTL8231 is
configured to use, if measuring pull-up/-down resistors is not an
option.
On an unsuccesful probe, the driver will log:
[ 0.795364] Probing RTL8231 GPIOs
[ 0.798978] rtl8231_init called, MDIO bus ID: 30
[ 0.804194] rtl8231-gpio rtl8231-gpio: no device found at bus address 30
When a device is found, only the first two lines will be logged:
[ 0.453698] Probing RTL8231 GPIOs
[ 0.457312] rtl8231_init called, MDIO bus ID: 31
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Tested-by: Stijn Tintel <stijn@linux-ipv6.be>
/* RTL8231 registers for LED control */
#define RTL8231_LED_FUNC0 0x0000
/* RTL8231 registers for LED control */
#define RTL8231_LED_FUNC0 0x0000
+#define RTL8231_LED_FUNC1 0x0001
+#define RTL8231_READY_MASK 0x03f0
+#define RTL8231_READY_VALUE 0x0370
#define RTL8231_GPIO_PIN_SEL(gpio) ((0x0002) + ((gpio) >> 4))
#define RTL8231_GPIO_DIR(gpio) ((0x0005) + ((gpio) >> 4))
#define RTL8231_GPIO_DATA(gpio) ((0x001C) + ((gpio) >> 4))
#define RTL8231_GPIO_PIN_SEL(gpio) ((0x0002) + ((gpio) >> 4))
#define RTL8231_GPIO_DIR(gpio) ((0x0005) + ((gpio) >> 4))
#define RTL8231_GPIO_DATA(gpio) ((0x001C) + ((gpio) >> 4))
int rtl8231_init(struct rtl8231_gpios *gpios)
{
int rtl8231_init(struct rtl8231_gpios *gpios)
{
pr_info("%s called, MDIO bus ID: %d\n", __func__, gpios->smi_bus_id);
gpios->reg_cached = 0;
pr_info("%s called, MDIO bus ID: %d\n", __func__, gpios->smi_bus_id);
gpios->reg_cached = 0;
sw_w32_mask(3, 1, RTL838X_DMY_REG5);
}
sw_w32_mask(3, 1, RTL838X_DMY_REG5);
}
+ ret = rtl8231_read(gpios, RTL8231_LED_FUNC1);
+ if ((ret & 0x80000000) || ((ret & RTL8231_READY_MASK) != RTL8231_READY_VALUE))
+ return -ENXIO;
+
/* Select GPIO functionality and force input direction for pins 0-36 */
rtl8231_write(gpios, RTL8231_GPIO_PIN_SEL(0), 0xffff);
rtl8231_write(gpios, RTL8231_GPIO_DIR(0), 0xffff);
/* Select GPIO functionality and force input direction for pins 0-36 */
rtl8231_write(gpios, RTL8231_GPIO_PIN_SEL(0), 0xffff);
rtl8231_write(gpios, RTL8231_GPIO_DIR(0), 0xffff);
+ err = rtl8231_init(gpios);
+ if (err) {
+ dev_err(dev, "no device found at bus address %d\n", gpios->smi_bus_id);
+ return err;
+ }
gpios->dev = dev;
gpios->gc.base = -1;
gpios->dev = dev;
gpios->gc.base = -1;