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authorDavid Daney <david.daney@cavium.com>2012-05-02 15:16:39 +0000
committerDavid S. Miller <davem@davemloft.net>2012-05-07 22:58:09 -0400
commit416912a129349788372e6ac27ab86bd9b18c8cc0 (patch)
tree239766992fc6878f89cce3037f65f757fc880dae /drivers/net/phy
parent0ca2997d145268e6b4ef000692061849cdab8348 (diff)
downloadop-kernel-dev-416912a129349788372e6ac27ab86bd9b18c8cc0.zip
op-kernel-dev-416912a129349788372e6ac27ab86bd9b18c8cc0.tar.gz
netdev/of/phy: Add MDIO bus multiplexer driven by GPIO lines.
The GPIO pins select which sub bus is connected to the master. Initially tested with an sn74cbtlv3253 switch device wired into the MDIO bus. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/phy')
-rw-r--r--drivers/net/phy/Kconfig10
-rw-r--r--drivers/net/phy/Makefile1
-rw-r--r--drivers/net/phy/mdio-mux-gpio.c142
3 files changed, 153 insertions, 0 deletions
diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 99c0674..944cdfb 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -144,6 +144,16 @@ config MDIO_BUS_MUX
to a parent bus. Switching between child busses is done by
device specific drivers.
+config MDIO_BUS_MUX_GPIO
+ tristate "Support for GPIO controlled MDIO bus multiplexers"
+ depends on OF_GPIO && OF_MDIO
+ select MDIO_BUS_MUX
+ help
+ This module provides a driver for MDIO bus multiplexers that
+ are controlled via GPIO lines. The multiplexer connects one of
+ several child MDIO busses to a parent bus. Child bus
+ selection is under the control of GPIO lines.
+
endif # PHYLIB
config MICREL_KS8995MA
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index a6b50e7..f51af68 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -26,3 +26,4 @@ obj-$(CONFIG_MDIO_OCTEON) += mdio-octeon.o
obj-$(CONFIG_MICREL_KS8995MA) += spi_ks8995.o
obj-$(CONFIG_AMD_PHY) += amd.o
obj-$(CONFIG_MDIO_BUS_MUX) += mdio-mux.o
+obj-$(CONFIG_MDIO_BUS_MUX_GPIO) += mdio-mux-gpio.o
diff --git a/drivers/net/phy/mdio-mux-gpio.c b/drivers/net/phy/mdio-mux-gpio.c
new file mode 100644
index 0000000..e0cc4ef
--- /dev/null
+++ b/drivers/net/phy/mdio-mux-gpio.c
@@ -0,0 +1,142 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2011, 2012 Cavium, Inc.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/device.h>
+#include <linux/of_mdio.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/phy.h>
+#include <linux/mdio-mux.h>
+#include <linux/of_gpio.h>
+
+#define DRV_VERSION "1.0"
+#define DRV_DESCRIPTION "GPIO controlled MDIO bus multiplexer driver"
+
+#define MDIO_MUX_GPIO_MAX_BITS 8
+
+struct mdio_mux_gpio_state {
+ int gpio[MDIO_MUX_GPIO_MAX_BITS];
+ unsigned int num_gpios;
+ void *mux_handle;
+};
+
+static int mdio_mux_gpio_switch_fn(int current_child, int desired_child,
+ void *data)
+{
+ int change;
+ unsigned int n;
+ struct mdio_mux_gpio_state *s = data;
+
+ if (current_child == desired_child)
+ return 0;
+
+ change = current_child == -1 ? -1 : current_child ^ desired_child;
+
+ for (n = 0; n < s->num_gpios; n++) {
+ if (change & 1)
+ gpio_set_value_cansleep(s->gpio[n],
+ (desired_child & 1) != 0);
+ change >>= 1;
+ desired_child >>= 1;
+ }
+
+ return 0;
+}
+
+static int __devinit mdio_mux_gpio_probe(struct platform_device *pdev)
+{
+ enum of_gpio_flags f;
+ struct mdio_mux_gpio_state *s;
+ unsigned int num_gpios;
+ unsigned int n;
+ int r;
+
+ if (!pdev->dev.of_node)
+ return -ENODEV;
+
+ num_gpios = of_gpio_count(pdev->dev.of_node);
+ if (num_gpios == 0 || num_gpios > MDIO_MUX_GPIO_MAX_BITS)
+ return -ENODEV;
+
+ s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ s->num_gpios = num_gpios;
+
+ for (n = 0; n < num_gpios; ) {
+ int gpio = of_get_gpio_flags(pdev->dev.of_node, n, &f);
+ if (gpio < 0) {
+ r = (gpio == -ENODEV) ? -EPROBE_DEFER : gpio;
+ goto err;
+ }
+ s->gpio[n] = gpio;
+
+ n++;
+
+ r = gpio_request(gpio, "mdio_mux_gpio");
+ if (r)
+ goto err;
+
+ r = gpio_direction_output(gpio, 0);
+ if (r)
+ goto err;
+ }
+
+ r = mdio_mux_init(&pdev->dev,
+ mdio_mux_gpio_switch_fn, &s->mux_handle, s);
+
+ if (r == 0) {
+ pdev->dev.platform_data = s;
+ return 0;
+ }
+err:
+ while (n) {
+ n--;
+ gpio_free(s->gpio[n]);
+ }
+ devm_kfree(&pdev->dev, s);
+ return r;
+}
+
+static int __devexit mdio_mux_gpio_remove(struct platform_device *pdev)
+{
+ struct mdio_mux_gpio_state *s = pdev->dev.platform_data;
+ mdio_mux_uninit(s->mux_handle);
+ return 0;
+}
+
+static struct of_device_id mdio_mux_gpio_match[] = {
+ {
+ .compatible = "mdio-mux-gpio",
+ },
+ {
+ /* Legacy compatible property. */
+ .compatible = "cavium,mdio-mux-sn74cbtlv3253",
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
+
+static struct platform_driver mdio_mux_gpio_driver = {
+ .driver = {
+ .name = "mdio-mux-gpio",
+ .owner = THIS_MODULE,
+ .of_match_table = mdio_mux_gpio_match,
+ },
+ .probe = mdio_mux_gpio_probe,
+ .remove = __devexit_p(mdio_mux_gpio_remove),
+};
+
+module_platform_driver(mdio_mux_gpio_driver);
+
+MODULE_DESCRIPTION(DRV_DESCRIPTION);
+MODULE_VERSION(DRV_VERSION);
+MODULE_AUTHOR("David Daney");
+MODULE_LICENSE("GPL");
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