From a93dfff10e067c152d4872719ec7837fcd8c94a3 Mon Sep 17 00:00:00 2001 From: Sander Vanheule Date: Sat, 20 Nov 2021 20:11:34 +0100 Subject: [PATCH] realtek: add RTL8231 chip detection 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 Tested-by: Stijn Tintel --- .../files-5.10/drivers/gpio/gpio-rtl8231.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/target/linux/realtek/files-5.10/drivers/gpio/gpio-rtl8231.c b/target/linux/realtek/files-5.10/drivers/gpio/gpio-rtl8231.c index d7643083da..7a1d6aa136 100644 --- a/target/linux/realtek/files-5.10/drivers/gpio/gpio-rtl8231.c +++ b/target/linux/realtek/files-5.10/drivers/gpio/gpio-rtl8231.c @@ -8,6 +8,9 @@ /* 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)) @@ -238,6 +241,8 @@ void rtl8231_gpio_set(struct gpio_chip *gc, unsigned int offset, int value) int rtl8231_init(struct rtl8231_gpios *gpios) { + u32 ret; + pr_info("%s called, MDIO bus ID: %d\n", __func__, gpios->smi_bus_id); gpios->reg_cached = 0; @@ -251,6 +256,10 @@ int rtl8231_init(struct rtl8231_gpios *gpios) 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); @@ -307,7 +316,11 @@ static int rtl8231_gpio_probe(struct platform_device *pdev) return err; } - rtl8231_init(gpios); + 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; -- 2.30.2