From cc30c16344fc3a25153175c7eb9037b2136cd466 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Fri, 20 Nov 2015 03:56:23 +0100 Subject: [PATCH 1/2] net: dsa: Add support for a switch reset gpio 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 Signed-off-by: David S. Miller --- .../devicetree/bindings/net/dsa/dsa.txt | 3 +++ include/net/dsa.h | 8 ++++++++ net/dsa/dsa.c | 17 +++++++++++++++++ 3 files changed, 28 insertions(+) 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..3f23dd9d6a69 100644 --- a/include/net/dsa.h +++ b/include/net/dsa.h @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -64,6 +65,13 @@ 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. + */ + struct gpio_desc *reset; }; struct dsa_platform_data { diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c index 1eba07feb34a..0b5565f923cc 100644 --- a/net/dsa/dsa.c +++ b/net/dsa/dsa.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include "dsa_priv.h" @@ -688,6 +689,9 @@ 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 of_flags; + unsigned long flags; u32 eeprom_len; int ret; @@ -766,6 +770,19 @@ static int dsa_of_probe(struct device *dev) put_device(cd->host_dev); cd->host_dev = &mdio_bus_switch->dev; } + gpio = of_get_named_gpio_flags(child, "reset-gpios", 0, + &of_flags); + if (gpio_is_valid(gpio)) { + flags = (of_flags == OF_GPIO_ACTIVE_LOW ? + GPIOF_ACTIVE_LOW : 0); + ret = devm_gpio_request_one(dev, gpio, flags, + "switch_reset"); + if (ret) + goto out_free_chip; + + cd->reset = gpio_to_desc(gpio); + gpiod_direction_output(cd->reset, 0); + } for_each_available_child_of_node(child, port) { port_reg = of_get_property(port, "reg", NULL); From c8c1b39a86940edd35439f1e5c9ff39888daf0f0 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Fri, 20 Nov 2015 03:56:24 +0100 Subject: [PATCH 2/2] dsa: mv88e6xxx.c: Hardware reset the chip if available The device tree binding now allows a gpio to be specified which is attached to the switch chips reset line. If it is defined, perform a hardware reset on the switch during setup. Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/dsa/mv88e6xxx.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c index b06dba05594a..75e245c4235e 100644 --- a/drivers/net/dsa/mv88e6xxx.c +++ b/drivers/net/dsa/mv88e6xxx.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -2323,6 +2324,7 @@ int mv88e6xxx_switch_reset(struct dsa_switch *ds, bool ppu_active) { struct mv88e6xxx_priv_state *ps = ds_to_priv(ds); u16 is_reset = (ppu_active ? 0x8800 : 0xc800); + struct gpio_desc *gpiod = ds->pd->reset; unsigned long timeout; int ret; int i; @@ -2336,6 +2338,14 @@ int mv88e6xxx_switch_reset(struct dsa_switch *ds, bool ppu_active) /* Wait for transmit queues to drain. */ usleep_range(2000, 4000); + /* If there is a gpio connected to the reset pin, toggle it */ + if (gpiod) { + gpiod_set_value_cansleep(gpiod, 1); + usleep_range(10000, 20000); + gpiod_set_value_cansleep(gpiod, 0); + usleep_range(10000, 20000); + } + /* Reset the switch. Keep the PPU active if requested. The PPU * needs to be active to support indirect phy register access * through global registers 0x18 and 0x19.