phy: Add driver for Exynos MIPI CSIS/DSIM DPHYs

Add a PHY provider driver for the Samsung S5P/Exynos SoC MIPI CSI-2
receiver and MIPI DSI transmitter DPHYs.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/phy/samsung-phy.txt

+Samsung S5P/EXYNOS SoC series MIPI CSIS/DSIM DPHY
+-------------------------------------------------
+
+Required properties:
+- compatible : should be "samsung,s5pv210-mipi-video-phy";
+- reg : offset and length of the MIPI DPHY register set;
+- #phy-cells : from the generic phy bindings, must be 1;
+
+For "samsung,s5pv210-mipi-video-phy" compatible PHYs the second cell in
+the PHY specifier identifies the PHY and its meaning is as follows:
+  0 - MIPI CSIS 0,
+  1 - MIPI DSIM 0,
+  2 - MIPI CSIS 1,
+  3 - MIPI DSIM 1.

drivers/phy/Kconfig

@@ -15,6 +15,12 @@ config GENERIC_PHY
 	  phy users can obtain reference to the PHY. All the users of this
 	  framework should select this config.
 
+config PHY_EXYNOS_MIPI_VIDEO
+	tristate "S5P/EXYNOS SoC series MIPI CSI-2/DSI PHY driver"
+	help
+	  Support for MIPI CSI-2 and MIPI DSI DPHY found on Samsung S5P
+	  and EXYNOS SoCs.
+
 config OMAP_USB2
 	tristate "OMAP USB2 PHY Driver"
 	depends on ARCH_OMAP2PLUS

drivers/phy/Makefile

@@ -3,5 +3,6 @@
 #
 
 obj-$(CONFIG_GENERIC_PHY)		+= phy-core.o
+obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO)	+= phy-exynos-mipi-video.o
 obj-$(CONFIG_OMAP_USB2)			+= phy-omap-usb2.o
 obj-$(CONFIG_TWL4030_USB)		+= phy-twl4030-usb.o

drivers/phy/phy-exynos-mipi-video.c

+/*
+ * Samsung S5P/EXYNOS SoC series MIPI CSIS/DSIM DPHY driver
+ *
+ * Copyright (C) 2013 Samsung Electronics Co., Ltd.
+ * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
+ *
+ * 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>
+
+/* MIPI_PHYn_CONTROL register offset: n = 0..1 */
+#define EXYNOS_MIPI_PHY_CONTROL(n)	((n) * 4)
+#define EXYNOS_MIPI_PHY_ENABLE		(1 << 0)
+#define EXYNOS_MIPI_PHY_SRESETN		(1 << 1)
+#define EXYNOS_MIPI_PHY_MRESETN		(1 << 2)
+#define EXYNOS_MIPI_PHY_RESET_MASK	(3 << 1)
+
+enum exynos_mipi_phy_id {
+	EXYNOS_MIPI_PHY_ID_CSIS0,
+	EXYNOS_MIPI_PHY_ID_DSIM0,
+	EXYNOS_MIPI_PHY_ID_CSIS1,
+	EXYNOS_MIPI_PHY_ID_DSIM1,
+	EXYNOS_MIPI_PHYS_NUM
+};
+
+#define is_mipi_dsim_phy_id(id) \
+	((id) == EXYNOS_MIPI_PHY_ID_DSIM0 || (id) == EXYNOS_MIPI_PHY_ID_DSIM1)
+
+struct exynos_mipi_video_phy {
+	spinlock_t slock;
+	struct video_phy_desc {
+		struct phy *phy;
+		unsigned int index;
+	} phys[EXYNOS_MIPI_PHYS_NUM];
+	void __iomem *regs;
+};
+
+static int __set_phy_state(struct exynos_mipi_video_phy *state,
+			enum exynos_mipi_phy_id id, unsigned int on)
+{
+	void __iomem *addr;
+	u32 reg, reset;
+
+	addr = state->regs + EXYNOS_MIPI_PHY_CONTROL(id / 2);
+
+	if (is_mipi_dsim_phy_id(id))
+		reset = EXYNOS_MIPI_PHY_MRESETN;
+	else
+		reset = EXYNOS_MIPI_PHY_SRESETN;
+
+	spin_lock(&state->slock);
+	reg = readl(addr);
+	if (on)
+		reg |= reset;
+	else
+		reg &= ~reset;
+	writel(reg, addr);
+
+	/* Clear ENABLE bit only if MRESETN, SRESETN bits are not set. */
+	if (on)
+		reg |= EXYNOS_MIPI_PHY_ENABLE;
+	else if (!(reg & EXYNOS_MIPI_PHY_RESET_MASK))
+		reg &= ~EXYNOS_MIPI_PHY_ENABLE;
+
+	writel(reg, addr);
+	spin_unlock(&state->slock);
+	return 0;
+}
+
+#define to_mipi_video_phy(desc) \
+	container_of((desc), struct exynos_mipi_video_phy, phys[(desc)->index]);
+
+static int exynos_mipi_video_phy_power_on(struct phy *phy)
+{
+	struct video_phy_desc *phy_desc = phy_get_drvdata(phy);
+	struct exynos_mipi_video_phy *state = to_mipi_video_phy(phy_desc);
+
+	return __set_phy_state(state, phy_desc->index, 1);
+}
+
+static int exynos_mipi_video_phy_power_off(struct phy *phy)
+{
+	struct video_phy_desc *phy_desc = phy_get_drvdata(phy);
+	struct exynos_mipi_video_phy *state = to_mipi_video_phy(phy_desc);
+
+	return __set_phy_state(state, phy_desc->index, 1);
+}
+
+static struct phy *exynos_mipi_video_phy_xlate(struct device *dev,
+					struct of_phandle_args *args)
+{
+	struct exynos_mipi_video_phy *state = dev_get_drvdata(dev);
+
+	if (WARN_ON(args->args[0] > EXYNOS_MIPI_PHYS_NUM))
+		return ERR_PTR(-ENODEV);
+
+	return state->phys[args->args[0]].phy;
+}
+
+static struct phy_ops exynos_mipi_video_phy_ops = {
+	.power_on	= exynos_mipi_video_phy_power_on,
+	.power_off	= exynos_mipi_video_phy_power_off,
+	.owner		= THIS_MODULE,
+};
+
+static int exynos_mipi_video_phy_probe(struct platform_device *pdev)
+{
+	struct exynos_mipi_video_phy *state;
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct phy_provider *phy_provider;
+	unsigned int i;
+
+	state = devm_kzalloc(dev, sizeof(*state), GFP_KERNEL);
+	if (!state)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	state->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(state->regs))
+		return PTR_ERR(state->regs);
+
+	dev_set_drvdata(dev, state);
+	spin_lock_init(&state->slock);
+
+	phy_provider = devm_of_phy_provider_register(dev,
+					exynos_mipi_video_phy_xlate);
+	if (IS_ERR(phy_provider))
+		return PTR_ERR(phy_provider);
+
+	for (i = 0; i < EXYNOS_MIPI_PHYS_NUM; i++) {
+		struct phy *phy = devm_phy_create(dev,
+					&exynos_mipi_video_phy_ops, NULL);
+		if (IS_ERR(phy)) {
+			dev_err(dev, "failed to create PHY %d\n", i);
+			return PTR_ERR(phy);
+		}
+
+		state->phys[i].phy = phy;
+		state->phys[i].index = i;
+		phy_set_drvdata(phy, &state->phys[i]);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id exynos_mipi_video_phy_of_match[] = {
+	{ .compatible = "samsung,s5pv210-mipi-video-phy" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, exynos_mipi_video_phy_of_match);
+
+static struct platform_driver exynos_mipi_video_phy_driver = {
+	.probe	= exynos_mipi_video_phy_probe,
+	.driver = {
+		.of_match_table	= exynos_mipi_video_phy_of_match,
+		.name  = "exynos-mipi-video-phy",
+		.owner = THIS_MODULE,
+	}
+};
+module_platform_driver(exynos_mipi_video_phy_driver);
+
+MODULE_DESCRIPTION("Samsung S5P/EXYNOS SoC MIPI CSI-2/DSI PHY driver");
+MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
+MODULE_LICENSE("GPL v2");