Re: [PATCH 2/2] usb: typec: add support for the nb7vpq904m Type-C Linear Redriver

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 

On 01/06/2023 11:37, Dmitry Baryshkov wrote:

On 01/06/2023 12:21, neil.armstrong@xxxxxxxxxx wrote:

From: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>

Add support for the ON Semiconductor NB7VPQ904M Type-C USB SuperSpeed
and DisplayPort ALT Mode Linear Redriver chip found on some devices
with a Type-C port.

The redriver compensates ultra High-Speeed DisplayPort and USB
Super Speed signal integrity losses mainly due to PCB & transmission
cables.

The redriver doesn't support SuperSpeed lines swapping, but
can support Type-C SBU lines swapping.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
---
  drivers/usb/typec/mux/Kconfig      |   8 +
  drivers/usb/typec/mux/Makefile     |   1 +
  drivers/usb/typec/mux/nb7vpq904m.c | 526 +++++++++++++++++++++++++++++++++++++
  3 files changed, 535 insertions(+)

diff --git a/drivers/usb/typec/mux/Kconfig b/drivers/usb/typec/mux/Kconfig
index c46fa4f9d3df..8c4d6b8fb75c 100644
--- a/drivers/usb/typec/mux/Kconfig
+++ b/drivers/usb/typec/mux/Kconfig
@@ -35,4 +35,12 @@ config TYPEC_MUX_INTEL_PMC
        control the USB role switch and also the multiplexer/demultiplexer
        switches used with USB Type-C Alternate Modes.
+config TYPEC_MUX_NB7VPQ904M
+    tristate "On Semiconductor NB7VPQ904M Type-C redriver driver"
+    depends on I2C
+    select REGMAP_I2C
+    help
+      Say Y or M if your system has a On Semiconductor NB7VPQ904M Type-C
+      redriver chip found on some devices with a Type-C port.
+
  endmenu
diff --git a/drivers/usb/typec/mux/Makefile b/drivers/usb/typec/mux/Makefile
index dda67e19b58b..76196096ef41 100644
--- a/drivers/usb/typec/mux/Makefile
+++ b/drivers/usb/typec/mux/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_TYPEC_MUX_FSA4480)        += fsa4480.o
  obj-$(CONFIG_TYPEC_MUX_GPIO_SBU)    += gpio-sbu-mux.o
  obj-$(CONFIG_TYPEC_MUX_PI3USB30532)    += pi3usb30532.o
  obj-$(CONFIG_TYPEC_MUX_INTEL_PMC)    += intel_pmc_mux.o
+obj-$(CONFIG_TYPEC_MUX_NB7VPQ904M)    += nb7vpq904m.o
diff --git a/drivers/usb/typec/mux/nb7vpq904m.c b/drivers/usb/typec/mux/nb7vpq904m.c
new file mode 100644
index 000000000000..2f85ad9e417a
--- /dev/null
+++ b/drivers/usb/typec/mux/nb7vpq904m.c
@@ -0,0 +1,526 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * OnSemi NB7VPQ904M Type-C driver
+ *
+ * Copyright (C) 2023 Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
+ */
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/of_graph.h>
+#include <drm/drm_bridge.h>
+#include <linux/usb/typec_dp.h>
+#include <linux/usb/typec_mux.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+
+#define NB7_CHNA        0
+#define NB7_CHNB        1
+#define NB7_CHNC        2
+#define NB7_CHND        3
+#define NB7_IS_CHAN_AD(channel) (channel == NB7_CHNA || channel == NB7_CHND)
+
+#define GEN_DEV_SET_REG            0x00
+
+#define GEN_DEV_SET_CHIP_EN        BIT(0)
+#define GEN_DEV_SET_CHNA_EN        BIT(4)
+#define GEN_DEV_SET_CHNB_EN        BIT(5)
+#define GEN_DEV_SET_CHNC_EN        BIT(6)
+#define GEN_DEV_SET_CHND_EN        BIT(7)
+
+#define GEN_DEV_SET_OP_MODE_MASK    GENMASK(3, 1)
+
+#define GEN_DEV_SET_OP_MODE_DP_CC2    0
+#define GEN_DEV_SET_OP_MODE_DP_CC1    1
+#define GEN_DEV_SET_OP_MODE_DP_4LANE    2
+#define GEN_DEV_SET_OP_MODE_USB        5
+
+#define EQ_SETTING_REG_BASE        0x01
+#define EQ_SETTING_REG(n)        (EQ_SETTING_REG_BASE + (n) * 2)
+#define EQ_SETTING_MASK            GENMASK(3, 1)
+
+#define OUTPUT_COMPRESSION_AND_POL_REG_BASE    0x02
+#define OUTPUT_COMPRESSION_AND_POL_REG(n)    (OUTPUT_COMPRESSION_AND_POL_REG_BASE + (n) * 2)
+#define OUTPUT_COMPRESSION_MASK        GENMASK(2, 1)
+
+#define FLAT_GAIN_REG_BASE        0x18
+#define FLAT_GAIN_REG(n)        (FLAT_GAIN_REG_BASE + (n) * 2)
+#define FLAT_GAIN_MASK            GENMASK(1, 0)
+
+#define LOSS_MATCH_REG_BASE        0x19
+#define LOSS_MATCH_REG(n)        (LOSS_MATCH_REG_BASE + (n) * 2)
+#define LOSS_MATCH_MASK            GENMASK(1, 0)
+
+#define AUX_CC_REG            0x09
+
+#define CHIP_VERSION_REG        0x17
+
+struct nb7vpq904m {
+    struct i2c_client *client;
+    struct gpio_desc *enable_gpio;
+    struct regulator *vcc_supply;
+    struct regmap *regmap;
+    struct typec_switch_dev *sw;
+    struct typec_mux_dev *mux;
+
+    bool swap_data_lanes;
+    struct typec_switch *typec_switch;
+
+    struct drm_bridge bridge;
+
+    struct mutex lock; /* protect non-concurrent mux & switch */
+
+    enum typec_orientation orientation;
+    unsigned long mode;
+    unsigned int svid;
+};
+
+static void nb7vpq904m_set_channel(struct nb7vpq904m *nb7, unsigned int channel, bool dp)
+{
+    u8 eq, out_comp, flat_gain, loss_match;
+
+    if (dp) {
+        eq = NB7_IS_CHAN_AD(channel) ? 0x6 : 0x4;
+        out_comp = 0x3;
+        flat_gain = NB7_IS_CHAN_AD(channel) ? 0x2 : 0x1;
+        loss_match = 0x3;
+    } else {
+        eq = 0x4;
+        out_comp = 0x3;
+        flat_gain = NB7_IS_CHAN_AD(channel) ? 0x3 : 0x1;
+        loss_match = NB7_IS_CHAN_AD(channel) ? 0x1 : 0x3;
+    }
+
+    regmap_update_bits(nb7->regmap, EQ_SETTING_REG(channel),
+               EQ_SETTING_MASK, FIELD_PREP(EQ_SETTING_MASK, eq));
+    regmap_update_bits(nb7->regmap, OUTPUT_COMPRESSION_AND_POL_REG(channel),
+               OUTPUT_COMPRESSION_MASK, FIELD_PREP(OUTPUT_COMPRESSION_MASK, out_comp));
+    regmap_update_bits(nb7->regmap, FLAT_GAIN_REG(channel),
+               FLAT_GAIN_MASK, FIELD_PREP(FLAT_GAIN_MASK, flat_gain));
+    regmap_update_bits(nb7->regmap, LOSS_MATCH_REG(channel),
+               LOSS_MATCH_MASK, FIELD_PREP(LOSS_MATCH_MASK, loss_match));
+}
+
+static int nb7vpq904m_set(struct nb7vpq904m *nb7)
+{
+    bool reverse = (nb7->orientation == TYPEC_ORIENTATION_REVERSE);
+
+    switch (nb7->mode) {
+    case TYPEC_STATE_SAFE:
+        regmap_write(nb7->regmap, GEN_DEV_SET_REG,
+                 GEN_DEV_SET_CHIP_EN |
+                 GEN_DEV_SET_CHNA_EN |
+                 GEN_DEV_SET_CHNB_EN |
+                 GEN_DEV_SET_CHNC_EN |
+                 GEN_DEV_SET_CHND_EN |
+                 FIELD_PREP(GEN_DEV_SET_OP_MODE_MASK,
+                    GEN_DEV_SET_OP_MODE_USB));
+        nb7vpq904m_set_channel(nb7, NB7_CHNA, false);
+        nb7vpq904m_set_channel(nb7, NB7_CHNB, false);
+        nb7vpq904m_set_channel(nb7, NB7_CHNC, false);
+        nb7vpq904m_set_channel(nb7, NB7_CHND, false);
+        regmap_write(nb7->regmap, AUX_CC_REG, 0x2);
+
+        return 0;
+
+    case TYPEC_STATE_USB:
+        /*
+         * Normal Orientation (CC1)
+         * A -> USB RX
+         * B -> USB TX
+         * C -> X
+         * D -> X
+         * Flipped Orientation (CC2)
+         * A -> X
+         * B -> X
+         * C -> USB TX
+         * D -> USB RX
+         *
+         * Reversed if data lanes are swapped
+         */
+        if (reverse ^ nb7->swap_data_lanes) {
+            regmap_write(nb7->regmap, GEN_DEV_SET_REG,
+                     GEN_DEV_SET_CHIP_EN |
+                     GEN_DEV_SET_CHNA_EN |
+                     GEN_DEV_SET_CHNB_EN |
+                     FIELD_PREP(GEN_DEV_SET_OP_MODE_MASK,
+                        GEN_DEV_SET_OP_MODE_USB));
+            nb7vpq904m_set_channel(nb7, NB7_CHNA, false);
+            nb7vpq904m_set_channel(nb7, NB7_CHNB, false);
+        } else {
+            regmap_write(nb7->regmap, GEN_DEV_SET_REG,
+                     GEN_DEV_SET_CHIP_EN |
+                     GEN_DEV_SET_CHNC_EN |
+                     GEN_DEV_SET_CHND_EN |
+                     FIELD_PREP(GEN_DEV_SET_OP_MODE_MASK,
+                        GEN_DEV_SET_OP_MODE_USB));
+            nb7vpq904m_set_channel(nb7, NB7_CHNC, false);
+            nb7vpq904m_set_channel(nb7, NB7_CHND, false);
+        }
+        regmap_write(nb7->regmap, AUX_CC_REG, 0x2);
+
+        return 0;
+
+    default:
+        if (nb7->svid != USB_TYPEC_DP_SID)
+            return -EINVAL;
+
+        break;
+    }
+
+    /* DP Altmode Setup */
+
+    regmap_write(nb7->regmap, AUX_CC_REG, reverse ? 0x1 : 0x0);
+
+    switch (nb7->mode) {
+    case TYPEC_DP_STATE_C:
+    case TYPEC_DP_STATE_E:
+        /*
+         * Normal Orientation (CC1)
+         * A -> DP3
+         * B -> DP2
+         * C -> DP1
+         * D -> DP0
+         * Flipped Orientation (CC2)
+         * A -> DP0
+         * B -> DP1
+         * C -> DP2
+         * D -> DP3
+         */
+        regmap_write(nb7->regmap, GEN_DEV_SET_REG,
+                 GEN_DEV_SET_CHIP_EN |
+                 GEN_DEV_SET_CHNA_EN |
+                 GEN_DEV_SET_CHNB_EN |
+                 GEN_DEV_SET_CHNC_EN |
+                 GEN_DEV_SET_CHND_EN |
+                 FIELD_PREP(GEN_DEV_SET_OP_MODE_MASK,
+                    GEN_DEV_SET_OP_MODE_DP_4LANE));
+        nb7vpq904m_set_channel(nb7, NB7_CHNA, true);
+        nb7vpq904m_set_channel(nb7, NB7_CHNB, true);
+        nb7vpq904m_set_channel(nb7, NB7_CHNC, true);
+        nb7vpq904m_set_channel(nb7, NB7_CHND, true);
+        break;
+
+    case TYPEC_DP_STATE_D:
+    case TYPEC_DP_STATE_F:
+        regmap_write(nb7->regmap, GEN_DEV_SET_REG,
+                 GEN_DEV_SET_CHIP_EN |
+                 GEN_DEV_SET_CHNA_EN |
+                 GEN_DEV_SET_CHNB_EN |
+                 GEN_DEV_SET_CHNC_EN |
+                 GEN_DEV_SET_CHND_EN |
+                 FIELD_PREP(GEN_DEV_SET_OP_MODE_MASK,
+                    reverse ^ nb7->swap_data_lanes ?
+                        GEN_DEV_SET_OP_MODE_DP_CC2
+                        : GEN_DEV_SET_OP_MODE_DP_CC1));
+
+        /*
+         * Normal Orientation (CC1)
+         * A -> USB RX
+         * B -> USB TX
+         * C -> DP1
+         * D -> DP0
+         * Flipped Orientation (CC2)
+         * A -> DP0
+         * B -> DP1
+         * C -> USB TX
+         * D -> USB RX
+         *
+         * Reversed if data lanes are swapped
+         */
+        if (nb7->swap_data_lanes) {
+            nb7vpq904m_set_channel(nb7, NB7_CHNA, !reverse);
+            nb7vpq904m_set_channel(nb7, NB7_CHNB, !reverse);
+            nb7vpq904m_set_channel(nb7, NB7_CHNC, reverse);
+            nb7vpq904m_set_channel(nb7, NB7_CHND, reverse);
+        } else {
+            nb7vpq904m_set_channel(nb7, NB7_CHNA, reverse);
+            nb7vpq904m_set_channel(nb7, NB7_CHNB, reverse);
+            nb7vpq904m_set_channel(nb7, NB7_CHNC, !reverse);
+            nb7vpq904m_set_channel(nb7, NB7_CHND, !reverse);
+        }
+        break;
+
+    default:
+        return -ENOTSUPP;
+    }
+
+    return 0;
+}
+
+static int nb7vpq904m_sw_set(struct typec_switch_dev *sw,
+                  enum typec_orientation orientation)
+{
+    struct nb7vpq904m *nb7 = typec_switch_get_drvdata(sw);
+    int ret;
+
+    ret = typec_switch_set(nb7->typec_switch, orientation);
+    if (ret)
+        return ret;
+
+    mutex_lock(&nb7->lock);
+
+    if (nb7->orientation != orientation) {
+        nb7->orientation = orientation;
+
+        ret = nb7vpq904m_set(nb7);
+    }
+
+    mutex_unlock(&nb7->lock);
+
+    return ret;
+}
+
+static int nb7vpq904m_mux_set(struct typec_mux_dev *mux, struct typec_mux_state *state)
+{
+    struct nb7vpq904m *nb7 = typec_mux_get_drvdata(mux);
+    int ret = 0;
+
+    mutex_lock(&nb7->lock);
+
+    if (nb7->mode != state->mode) {
+        nb7->mode = state->mode;
+
+        if (state->alt)
+            nb7->svid = state->alt->svid;
+        else
+            nb7->svid = 0; // No SVID
+
+        ret = nb7vpq904m_set(nb7);
+    }
+
+    mutex_unlock(&nb7->lock);
+
+    return ret;
+}
+
+#if IS_ENABLED(CONFIG_DRM)
+static int nb7vpq904m_bridge_attach(struct drm_bridge *bridge,
+                    enum drm_bridge_attach_flags flags)
+{
+    struct nb7vpq904m *nb7 = container_of(bridge, struct nb7vpq904m, bridge);
+    struct drm_bridge *next_bridge;
+
+    if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
+        return -EINVAL;
+
+    next_bridge = devm_drm_of_get_bridge(&nb7->client->dev, nb7->client->dev.of_node, 0, 0);
+    if (IS_ERR(next_bridge)) {
+        dev_err(&nb7->client->dev, "failed to acquire drm_bridge: %pe\n", next_bridge);
+        return PTR_ERR(next_bridge);
+    }
+
+    return drm_bridge_attach(bridge->encoder, next_bridge, bridge,
+                 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+}
+
+static const struct drm_bridge_funcs nb7vpq904m_bridge_funcs = {
+    .attach    = nb7vpq904m_bridge_attach,
+};
+
+static int nb7vpq904m_register_bridge(struct nb7vpq904m *nb7)
+{
+    nb7->bridge.funcs = &nb7vpq904m_bridge_funcs;
+    nb7->bridge.of_node = nb7->client->dev.of_node;
+
+    return devm_drm_bridge_add(&nb7->client->dev, &nb7->bridge);
+}
+#else
+static int nb7vpq904m_register_bridge(struct nb7vpq904m *nb7)
+{
+    return 0;
+}
+#endif


This is what I feared of when we started mixing USB-C and drm bridges. A part of me still thinks that the proper solution should involve OOB notifications.



OOB looks nice, but as I lookes, it would require a large amount of changes.

The advantage of bridge chaining is we can add specific ops for prepare/enable/disable/unprepare
for each elements of the USB-C data path.


If we can expect a sizeable amount of such drivers, can we have a generic drm helper for such passthrough bridges?


Sure, we can add this to drm-bridge.c as a simple pass-throught bridge code

Neil




+
+static const struct regmap_config nb7_regmap = {
+    .max_register = 0x1f,
+    .reg_bits = 8,
+    .val_bits = 8,
+};
+
+enum {
+    NORMAL_LANE_MAPPING,
+    INVERT_LANE_MAPPING,
+};
+
+#define DATA_LANES_COUNT    4
+
+static const int supported_data_lane_mapping[][DATA_LANES_COUNT] = {
+    [NORMAL_LANE_MAPPING] = { 0, 1, 2, 3 },
+    [INVERT_LANE_MAPPING] = { 2, 3, 0, 1 },
+};
+
+static int nb7vpq904m_parse_data_lanes_mapping(struct nb7vpq904m *nb7)
+{
+    struct device_node *ep;
+    u32 data_lanes[4];
+    int ret, i, j;
+
+    ep = of_graph_get_endpoint_by_regs(nb7->client->dev.of_node, 1, 0);
+
+    if (ep) {
+        ret = of_property_count_u32_elems(ep, "data-lanes");
+        if (ret == -EINVAL)
+            /* Property isn't here, consider default mapping */
+            goto out_done;
+        if (ret < 0)
+            goto out_error;
+
+        if (ret != DATA_LANES_COUNT) {
+            dev_err(&nb7->client->dev, "expected 4 data lanes\n");
+            ret = -EINVAL;
+            goto out_error;
+        }
+
+        ret = of_property_read_u32_array(ep, "data-lanes", data_lanes, DATA_LANES_COUNT);
+        if (ret)
+            goto out_error;
+
+        for (i = 0; i < ARRAY_SIZE(supported_data_lane_mapping); i++) {
+            for (j = 0; j < DATA_LANES_COUNT; j++) {
+                if (data_lanes[j] != supported_data_lane_mapping[i][j])
+                    break;
+            }
+
+            if (j == DATA_LANES_COUNT)
+                break;
+        }
+
+        switch (i) {
+        case NORMAL_LANE_MAPPING:
+            break;
+        case INVERT_LANE_MAPPING:
+            nb7->swap_data_lanes = true;
+            dev_info(&nb7->client->dev, "using inverted data lanes mapping\n");
+            break;
+        default:
+            dev_err(&nb7->client->dev, "invalid data lanes mapping\n");
+            ret = -EINVAL;
+            goto out_error;
+        }
+    }
+
+out_done:
+    ret = 0;
+
+out_error:
+    of_node_put(ep);
+
+    return ret;
+}
+
+static int nb7vpq904m_probe(struct i2c_client *client)
+{
+    struct device *dev = &client->dev;
+    struct typec_switch_desc sw_desc = { };
+    struct typec_mux_desc mux_desc = { };
+    struct nb7vpq904m *nb7;
+    int ret;
+
+    nb7 = devm_kzalloc(dev, sizeof(*nb7), GFP_KERNEL);
+    if (!nb7)
+        return -ENOMEM;
+
+    nb7->client = client;
+
+    nb7->regmap = devm_regmap_init_i2c(client, &nb7_regmap);
+    if (IS_ERR(nb7->regmap)) {
+        dev_err(&client->dev, "Failed to allocate register map\n");
+        return PTR_ERR(nb7->regmap);
+    }
+
+    nb7->mode = TYPEC_STATE_SAFE;
+    nb7->orientation = TYPEC_ORIENTATION_NONE;
+
+    mutex_init(&nb7->lock);
+
+    nb7->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
+    if (IS_ERR(nb7->enable_gpio))
+        return dev_err_probe(dev, PTR_ERR(nb7->enable_gpio),
+                     "unable to acquire enable gpio\n");
+
+    nb7->vcc_supply = devm_regulator_get_optional(dev, "vcc");
+    if (IS_ERR(nb7->vcc_supply))
+        return PTR_ERR(nb7->vcc_supply);
+
+    nb7->typec_switch = fwnode_typec_switch_get(dev->fwnode);
+    if (IS_ERR(nb7->typec_switch))
+        return dev_err_probe(dev, PTR_ERR(nb7->typec_switch),
+                     "failed to acquire orientation-switch\n");
+
+    ret = nb7vpq904m_parse_data_lanes_mapping(nb7);
+    if (ret)
+        return ret;
+
+    ret = regulator_enable(nb7->vcc_supply);
+    if (ret)
+        dev_warn(dev, "Failed to enable vcc: %d\n", ret);
+
+    gpiod_set_value(nb7->enable_gpio, 1);
+
+    ret = nb7vpq904m_register_bridge(nb7);
+    if (ret)
+        return ret;
+
+    sw_desc.drvdata = nb7;
+    sw_desc.fwnode = dev->fwnode;
+    sw_desc.set = nb7vpq904m_sw_set;
+
+    nb7->sw = typec_switch_register(dev, &sw_desc);
+    if (IS_ERR(nb7->sw))
+        return dev_err_probe(dev, PTR_ERR(nb7->sw), "Error registering typec switch\n");
+
+    mux_desc.drvdata = nb7;
+    mux_desc.fwnode = dev->fwnode;
+    mux_desc.set = nb7vpq904m_mux_set;
+
+    nb7->mux = typec_mux_register(dev, &mux_desc);
+    if (IS_ERR(nb7->mux)) {
+        typec_switch_unregister(nb7->sw);
+        return dev_err_probe(dev, PTR_ERR(nb7->mux), "Error registering typec mux\n");
+    }
+
+    return 0;
+}
+
+static void nb7vpq904m_remove(struct i2c_client *client)
+{
+    struct nb7vpq904m *nb7 = i2c_get_clientdata(client);
+
+    typec_mux_unregister(nb7->mux);
+    typec_switch_unregister(nb7->sw);
+
+    gpiod_set_value(nb7->enable_gpio, 0);
+
+    regulator_disable(nb7->vcc_supply);
+}
+
+static const struct i2c_device_id nb7vpq904m_table[] = {
+    { "nb7vpq904m" },
+    { }
+};
+MODULE_DEVICE_TABLE(i2c, nb7vpq904m_table);
+
+static const struct of_device_id nb7vpq904m_of_table[] = {
+    { .compatible = "onnn,nb7vpq904m" },
+    { }
+};
+MODULE_DEVICE_TABLE(of, nb7vpq904m_of_table);
+
+static struct i2c_driver nb7vpq904m_driver = {
+    .driver = {
+        .name = "nb7vpq904m",
+        .of_match_table = nb7vpq904m_of_table,
+    },
+    .probe_new    = nb7vpq904m_probe,
+    .remove        = nb7vpq904m_remove,
+    .id_table    = nb7vpq904m_table,
+};
+
+module_i2c_driver(nb7vpq904m_driver);
+
+MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>");
+MODULE_DESCRIPTION("OnSemi NB7VPQ904M Type-C driver");
+MODULE_LICENSE("GPL");
[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]

  Powered by Linux