[RFC 04/12] phy: Add simple-phy driver

[Tomasz Stanislawski]

Add simple-phy driver to support a single register
PHY interfaces present on Exynos4 SoC.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@xxxxxxxxxxx>
---
 drivers/phy/Kconfig      |    5 ++
 drivers/phy/Makefile     |    1 +
 drivers/phy/phy-simple.c |  128 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 134 insertions(+)
 create mode 100644 drivers/phy/phy-simple.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index ac239ac..619c657 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -38,4 +38,9 @@ config TWL4030_USB
 	  This transceiver supports high and full speed devices plus,
 	  in host mode, low speed.
 
+config PHY_SIMPLE
+	tristate "Simple PHY driver"
+	help
+	  Support for PHY controllers configured using single register.
+
 endmenu
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 0dd8a98..3d68e19 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -5,3 +5,4 @@
 obj-$(CONFIG_GENERIC_PHY)	+= phy-core.o
 obj-$(CONFIG_OMAP_USB2)		+= phy-omap-usb2.o
 obj-$(CONFIG_TWL4030_USB)	+= phy-twl4030-usb.o
+obj-$(CONFIG_PHY_SIMPLE)	+= phy-simple.o
diff --git a/drivers/phy/phy-simple.c b/drivers/phy/phy-simple.c
new file mode 100644
index 0000000..4a28af7
--- /dev/null
+++ b/drivers/phy/phy-simple.c
@@ -0,0 +1,128 @@
+/*
+ * Simple PHY driver
+ *
+ * Copyright (C) 2013 Samsung Electronics Co., Ltd.
+ * Author: Tomasz Stanislawski <t.stanislaws@xxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+struct simple_phy {
+	spinlock_t slock;
+	u32 on_value;
+	u32 off_value;
+	u32 mask;
+	void __iomem *regs;
+};
+
+static int sphy_set(struct simple_phy *sphy, bool on)
+{
+	u32 reg;
+
+	spin_lock(&sphy->slock);
+
+	reg = readl(sphy->regs);
+	reg &= ~sphy->mask;
+	reg |= sphy->mask & (on ? sphy->on_value : sphy->off_value);
+	writel(reg, sphy->regs);
+
+	spin_unlock(&sphy->slock);
+
+	return 0;
+}
+
+static int simple_phy_power_on(struct phy *phy)
+{
+	return sphy_set(phy_get_drvdata(phy), 1);
+}
+
+static int simple_phy_power_off(struct phy *phy)
+{
+	return sphy_set(phy_get_drvdata(phy), 0);
+}
+
+static struct phy_ops simple_phy_ops = {
+	.power_on	= simple_phy_power_on,
+	.power_off	= simple_phy_power_off,
+	.owner		= THIS_MODULE,
+};
+
+static int simple_phy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct simple_phy *sphy;
+	struct resource *res;
+	struct phy_provider *phy_provider;
+	struct phy *phy;
+
+	sphy = devm_kzalloc(dev, sizeof(*sphy), GFP_KERNEL);
+	if (!sphy)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	sphy->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(sphy->regs)) {
+		dev_err(dev, "failed to ioremap registers\n");
+		return PTR_ERR(sphy->regs);
+	}
+
+	spin_lock_init(&sphy->slock);
+
+	phy_provider = devm_of_phy_provider_register(dev, NULL);
+	if (IS_ERR(phy_provider)) {
+		dev_err(dev, "failed to register PHY provider\n");
+		return PTR_ERR(phy_provider);
+	}
+
+	phy = devm_phy_create(dev, &simple_phy_ops, NULL);
+	if (IS_ERR(phy)) {
+		dev_err(dev, "failed to create PHY\n");
+		return PTR_ERR(phy);
+	}
+
+	sphy->mask = 1;
+	sphy->on_value = ~0;
+	sphy->off_value = 0;
+
+	of_property_read_u32(dev->of_node, "mask", &sphy->mask);
+	of_property_read_u32(dev->of_node, "on-value", &sphy->on_value);
+	of_property_read_u32(dev->of_node, "off-value", &sphy->off_value);
+
+	phy_set_drvdata(phy, sphy);
+
+	dev_info(dev, "probe successful\n");
+
+	return 0;
+}
+
+static const struct of_device_id simple_phy_of_match[] = {
+	{ .compatible = "simple-phy" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, simple_phy_of_match);
+
+static struct platform_driver simple_phy_driver = {
+	.probe	= simple_phy_probe,
+	.driver = {
+		.of_match_table	= simple_phy_of_match,
+		.name  = "simple-phy",
+		.owner = THIS_MODULE,
+	}
+};
+module_platform_driver(simple_phy_driver);
+
+MODULE_DESCRIPTION("Simple PHY driver");
+MODULE_AUTHOR("Tomasz Stanislawski <t.stanislaws@xxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
-- 
1.7.9.5

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