diff options
Diffstat (limited to 'drivers/net/ethernet/smsc/smc91x.c')
| -rw-r--r-- | drivers/net/ethernet/smsc/smc91x.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/drivers/net/ethernet/smsc/smc91x.c b/drivers/net/ethernet/smsc/smc91x.c index 5e94d00b96b3..2c62208077fe 100644 --- a/drivers/net/ethernet/smsc/smc91x.c +++ b/drivers/net/ethernet/smsc/smc91x.c @@ -81,6 +81,7 @@ static const char version[] = #include <linux/workqueue.h> #include <linux/of.h> #include <linux/of_device.h> +#include <linux/of_gpio.h> #include <linux/netdevice.h> #include <linux/etherdevice.h> @@ -2188,6 +2189,41 @@ static const struct of_device_id smc91x_match[] = { {}, }; MODULE_DEVICE_TABLE(of, smc91x_match); + +/** + * of_try_set_control_gpio - configure a gpio if it exists + */ +static int try_toggle_control_gpio(struct device *dev, + struct gpio_desc **desc, + const char *name, int index, + int value, unsigned int nsdelay) +{ + struct gpio_desc *gpio = *desc; + int res; + + gpio = devm_gpiod_get_index(dev, name, index); + if (IS_ERR(gpio)) { + if (PTR_ERR(gpio) == -ENOENT) { + *desc = NULL; + return 0; + } + + return PTR_ERR(gpio); + } + res = gpiod_direction_output(gpio, !value); + if (res) { + dev_err(dev, "unable to toggle gpio %s: %i\n", name, res); + devm_gpiod_put(dev, gpio); + gpio = NULL; + return res; + } + if (nsdelay) + usleep_range(nsdelay, 2 * nsdelay); + gpiod_set_value_cansleep(gpio, value); + *desc = gpio; + + return 0; +} #endif /* @@ -2237,6 +2273,28 @@ static int smc_drv_probe(struct platform_device *pdev) struct device_node *np = pdev->dev.of_node; u32 val; + /* Optional pwrdwn GPIO configured? */ + ret = try_toggle_control_gpio(&pdev->dev, &lp->power_gpio, + "power", 0, 0, 100); + if (ret) + return ret; + + /* + * Optional reset GPIO configured? Minimum 100 ns reset needed + * according to LAN91C96 datasheet page 14. + */ + ret = try_toggle_control_gpio(&pdev->dev, &lp->reset_gpio, + "reset", 0, 0, 100); + if (ret) + return ret; + + /* + * Need to wait for optional EEPROM to load, max 750 us according + * to LAN91C96 datasheet page 55. + */ + if (lp->reset_gpio) + usleep_range(750, 1000); + /* Combination of IO widths supported, default to 16-bit */ if (!of_property_read_u32(np, "reg-io-width", &val)) { if (val & 1) |
