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>

4 files changed, 200 insertions, 3 deletions

diff --git a/Documentation/devicetree/bindings/phy/samsung-phy.txt b/Documentation/devicetree/bindings/phy/samsung-phy.txt
new file mode 100644
index 000000000000..5ff208c7f1f2
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/samsung-phy.txt
@@ -0,0 +1,14 @@
+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.
diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index ac239aca77ec..0062d7e60dbe 100644
--- a/drivers/phy/Kconfig
+++ b/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
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 0dd8a9834548..6344053661f4 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -2,6 +2,7 @@
 # Makefile for the phy drivers.
 #
 
-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_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
diff --git a/drivers/phy/phy-exynos-mipi-video.c b/drivers/phy/phy-exynos-mipi-video.c
new file mode 100644
index 000000000000..b73b86ab4697
--- /dev/null
+++ b/drivers/phy/phy-exynos-mipi-video.c
@@ -0,0 +1,176 @@
+/*
+ * 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");