| Message ID | 1447889365-25256-2-git-send-email-andrew@lunn.ch |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
> index 1eba07feb34a..39cd19eaaf4e 100644 > --- a/net/dsa/dsa.c > +++ b/net/dsa/dsa.c > @@ -21,6 +21,8 @@ > #include <linux/of_mdio.h> > #include <linux/of_platform.h> > #include <linux/of_net.h> > +#include <linux/nvmem-consumer.h> Comment to self: That include should not be there. I will post a v2 once the discussion has stopped. Andrew -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Andrew, On 11/19/2015 12:29 AM, Andrew Lunn wrote: > + gpio = of_get_named_gpio_flags(child, "reset-gpios", 0, > + &flags); > + if (gpio_is_valid(gpio)) { > + ret = devm_gpio_request_one(dev, gpio, flags, > + "switch_reset"); > + if (ret) > + goto out_free_chip; > + > + cd->reset = gpio; > + cd->reset_flags = flags; > + off = (flags && OF_GPIO_ACTIVE_LOW ? 1 : 0); > + gpio_direction_output(cd->reset, off); > + } > + > for_each_available_child_of_node(child, port) { > port_reg = of_get_property(port, "reg", NULL); > if (!port_reg) > You could also use : gpio = of_get_named_gpio(child, "reset-gpios", 0) devm_gpio_request(dev, gpio, "switch_reset") and : cd->reset = gpio_to_desc(gpio); and cd->switch reset to struct gpio_desc *reset to use the gpiod calls afterward. The flags are no more needed. Neil -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Nov 19, 2015 at 09:39:11AM +0100, Neil Armstrong wrote: > Hi Andrew, > > On 11/19/2015 12:29 AM, Andrew Lunn wrote: > > + gpio = of_get_named_gpio_flags(child, "reset-gpios", 0, > > + &flags); > > + if (gpio_is_valid(gpio)) { > > + ret = devm_gpio_request_one(dev, gpio, flags, > > + "switch_reset"); > > + if (ret) > > + goto out_free_chip; > > + > > + cd->reset = gpio; > > + cd->reset_flags = flags; > > + off = (flags && OF_GPIO_ACTIVE_LOW ? 1 : 0); > > + gpio_direction_output(cd->reset, off); > > + } > > + > > for_each_available_child_of_node(child, port) { > > port_reg = of_get_property(port, "reg", NULL); > > if (!port_reg) > > > > You could also use : > gpio = of_get_named_gpio(child, "reset-gpios", 0) > devm_gpio_request(dev, gpio, "switch_reset") > > and : > cd->reset = gpio_to_desc(gpio); > > and cd->switch reset to struct gpio_desc *reset > > to use the gpiod calls afterward. The flags are no more needed. Hi Neil I really wanted to use gpiod, since as you said, it takes care of active low/active high. I tried all sorts of combinations. The problem with this one is that desc->flags is set in gpiod_parse_flags(), which is only called from gpiod_get_index(), which is limited to gpios in the root of the devices subtree. I was 'lucky' in that my reset is active low, so i noticed the problem when my switch failed to probe, being held in reset, because the ACTIVE_LOW flag in DT is being ignored. It seems like gpiod is backwards compatible to gpio, but gpio is not forward compatible to gpiod. Andrew -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/devicetree/bindings/net/dsa/dsa.txt b/Documentation/devicetree/bindings/net/dsa/dsa.txt index 04e6bef3ac3f..5fdbbcdf8c4b 100644 --- a/Documentation/devicetree/bindings/net/dsa/dsa.txt +++ b/Documentation/devicetree/bindings/net/dsa/dsa.txt @@ -31,6 +31,8 @@ A switch child node has the following optional property: switch. Must be set if the switch can not detect the presence and/or size of a connected EEPROM, otherwise optional. +- reset-gpios : phandle and specifier to a gpio line connected to + reset pin of the switch chip. A switch may have multiple "port" children nodes @@ -114,6 +116,7 @@ Example: #size-cells = <0>; reg = <17 1>; /* MDIO address 17, switch 1 in tree */ mii-bus = <&mii_bus1>; + reset-gpios = <&gpio5 1 GPIO_ACTIVE_LOW>; switch1port0: port@0 { reg = <0>; diff --git a/include/net/dsa.h b/include/net/dsa.h index 82a4c6011173..913a61ea81d3 100644 --- a/include/net/dsa.h +++ b/include/net/dsa.h @@ -16,6 +16,7 @@ #include <linux/timer.h> #include <linux/workqueue.h> #include <linux/of.h> +#include <linux/of_gpio.h> #include <linux/phy.h> #include <linux/phy_fixed.h> #include <linux/ethtool.h> @@ -64,6 +65,14 @@ struct dsa_chip_data { * NULL if there is only one switch chip. */ s8 *rtable; + + /* + * A switch may have a GPIO line tied to its reset pin. Parse + * this from the device tree, and use it before performing + * switch soft reset. + */ + int reset; + enum of_gpio_flags reset_flags; }; struct dsa_platform_data { diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c index 1eba07feb34a..39cd19eaaf4e 100644 --- a/net/dsa/dsa.c +++ b/net/dsa/dsa.c @@ -21,6 +21,8 @@ #include <linux/of_mdio.h> #include <linux/of_platform.h> #include <linux/of_net.h> +#include <linux/nvmem-consumer.h> +#include <linux/of_gpio.h> #include <linux/sysfs.h> #include <linux/phy_fixed.h> #include "dsa_priv.h" @@ -688,6 +690,9 @@ static int dsa_of_probe(struct device *dev) const char *port_name; int chip_index, port_index; const unsigned int *sw_addr, *port_reg; + int gpio; + enum of_gpio_flags flags; + int off; u32 eeprom_len; int ret; @@ -767,6 +772,20 @@ static int dsa_of_probe(struct device *dev) cd->host_dev = &mdio_bus_switch->dev; } + gpio = of_get_named_gpio_flags(child, "reset-gpios", 0, + &flags); + if (gpio_is_valid(gpio)) { + ret = devm_gpio_request_one(dev, gpio, flags, + "switch_reset"); + if (ret) + goto out_free_chip; + + cd->reset = gpio; + cd->reset_flags = flags; + off = (flags && OF_GPIO_ACTIVE_LOW ? 1 : 0); + gpio_direction_output(cd->reset, off); + } + for_each_available_child_of_node(child, port) { port_reg = of_get_property(port, "reg", NULL); if (!port_reg)
Some boards have a gpio line tied to the switch reset pin. Allow this gpio to be retrieved from the device tree, and take the switch out of reset before performing the probe. Signed-off-by: Andrew Lunn <andrew@lunn.ch> --- Documentation/devicetree/bindings/net/dsa/dsa.txt | 3 +++ include/net/dsa.h | 9 +++++++++ net/dsa/dsa.c | 19 +++++++++++++++++++ 3 files changed, 31 insertions(+)