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path: root/drivers/clk/renesas/rcar-usb2-clock-sel.c
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Diffstat (limited to 'drivers/clk/renesas/rcar-usb2-clock-sel.c')
-rw-r--r--drivers/clk/renesas/rcar-usb2-clock-sel.c226
1 files changed, 226 insertions, 0 deletions
diff --git a/drivers/clk/renesas/rcar-usb2-clock-sel.c b/drivers/clk/renesas/rcar-usb2-clock-sel.c
new file mode 100644
index 000000000..7a64dcb72
--- /dev/null
+++ b/drivers/clk/renesas/rcar-usb2-clock-sel.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas R-Car USB2.0 clock selector
+ *
+ * Copyright (C) 2017 Renesas Electronics Corp.
+ *
+ * Based on renesas-cpg-mssr.c
+ *
+ * Copyright (C) 2015 Glider bvba
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+
+#define USB20_CLKSET0 0x00
+#define CLKSET0_INTCLK_EN BIT(11)
+#define CLKSET0_PRIVATE BIT(0)
+#define CLKSET0_EXTAL_ONLY (CLKSET0_INTCLK_EN | CLKSET0_PRIVATE)
+
+static const struct clk_bulk_data rcar_usb2_clocks[] = {
+ { .id = "ehci_ohci", },
+ { .id = "hs-usb-if", },
+};
+
+struct usb2_clock_sel_priv {
+ void __iomem *base;
+ struct clk_hw hw;
+ struct clk_bulk_data clks[ARRAY_SIZE(rcar_usb2_clocks)];
+ struct reset_control *rsts;
+ bool extal;
+ bool xtal;
+};
+#define to_priv(_hw) container_of(_hw, struct usb2_clock_sel_priv, hw)
+
+static void usb2_clock_sel_enable_extal_only(struct usb2_clock_sel_priv *priv)
+{
+ u16 val = readw(priv->base + USB20_CLKSET0);
+
+ pr_debug("%s: enter %d %d %x\n", __func__,
+ priv->extal, priv->xtal, val);
+
+ if (priv->extal && !priv->xtal && val != CLKSET0_EXTAL_ONLY)
+ writew(CLKSET0_EXTAL_ONLY, priv->base + USB20_CLKSET0);
+}
+
+static void usb2_clock_sel_disable_extal_only(struct usb2_clock_sel_priv *priv)
+{
+ if (priv->extal && !priv->xtal)
+ writew(CLKSET0_PRIVATE, priv->base + USB20_CLKSET0);
+}
+
+static int usb2_clock_sel_enable(struct clk_hw *hw)
+{
+ struct usb2_clock_sel_priv *priv = to_priv(hw);
+ int ret;
+
+ ret = reset_control_deassert(priv->rsts);
+ if (ret)
+ return ret;
+
+ ret = clk_bulk_prepare_enable(ARRAY_SIZE(priv->clks), priv->clks);
+ if (ret) {
+ reset_control_assert(priv->rsts);
+ return ret;
+ }
+
+ usb2_clock_sel_enable_extal_only(priv);
+
+ return 0;
+}
+
+static void usb2_clock_sel_disable(struct clk_hw *hw)
+{
+ struct usb2_clock_sel_priv *priv = to_priv(hw);
+
+ usb2_clock_sel_disable_extal_only(priv);
+
+ clk_bulk_disable_unprepare(ARRAY_SIZE(priv->clks), priv->clks);
+ reset_control_assert(priv->rsts);
+}
+
+/*
+ * This module seems a mux, but this driver assumes a gate because
+ * ehci/ohci platform drivers don't support clk_set_parent() for now.
+ * If this driver acts as a gate, ehci/ohci-platform drivers don't need
+ * any modification.
+ */
+static const struct clk_ops usb2_clock_sel_clock_ops = {
+ .enable = usb2_clock_sel_enable,
+ .disable = usb2_clock_sel_disable,
+};
+
+static const struct of_device_id rcar_usb2_clock_sel_match[] = {
+ { .compatible = "renesas,rcar-gen3-usb2-clock-sel" },
+ { }
+};
+
+static int rcar_usb2_clock_sel_suspend(struct device *dev)
+{
+ struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev);
+
+ usb2_clock_sel_disable_extal_only(priv);
+ pm_runtime_put(dev);
+
+ return 0;
+}
+
+static int rcar_usb2_clock_sel_resume(struct device *dev)
+{
+ struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev);
+
+ pm_runtime_get_sync(dev);
+ usb2_clock_sel_enable_extal_only(priv);
+
+ return 0;
+}
+
+static int rcar_usb2_clock_sel_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+
+ of_clk_del_provider(dev->of_node);
+ pm_runtime_put(dev);
+ pm_runtime_disable(dev);
+
+ return 0;
+}
+
+static int rcar_usb2_clock_sel_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct usb2_clock_sel_priv *priv;
+ struct clk *clk;
+ struct clk_init_data init;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);
+
+ memcpy(priv->clks, rcar_usb2_clocks, sizeof(priv->clks));
+ ret = devm_clk_bulk_get(dev, ARRAY_SIZE(priv->clks), priv->clks);
+ if (ret < 0)
+ return ret;
+
+ priv->rsts = devm_reset_control_array_get(dev, true, false);
+ if (IS_ERR(priv->rsts))
+ return PTR_ERR(priv->rsts);
+
+ clk = devm_clk_get(dev, "usb_extal");
+ if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
+ priv->extal = !!clk_get_rate(clk);
+ clk_disable_unprepare(clk);
+ }
+ clk = devm_clk_get(dev, "usb_xtal");
+ if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
+ priv->xtal = !!clk_get_rate(clk);
+ clk_disable_unprepare(clk);
+ }
+
+ if (!priv->extal && !priv->xtal) {
+ dev_err(dev, "This driver needs usb_extal or usb_xtal\n");
+ return -ENOENT;
+ }
+
+ pm_runtime_enable(dev);
+ pm_runtime_get_sync(dev);
+ platform_set_drvdata(pdev, priv);
+ dev_set_drvdata(dev, priv);
+
+ init.name = "rcar_usb2_clock_sel";
+ init.ops = &usb2_clock_sel_clock_ops;
+ init.flags = 0;
+ init.parent_names = NULL;
+ init.num_parents = 0;
+ priv->hw.init = &init;
+
+ ret = devm_clk_hw_register(dev, &priv->hw);
+ if (ret)
+ goto pm_put;
+
+ ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw);
+ if (ret)
+ goto pm_put;
+
+ return 0;
+
+pm_put:
+ pm_runtime_put(dev);
+ pm_runtime_disable(dev);
+ return ret;
+}
+
+static const struct dev_pm_ops rcar_usb2_clock_sel_pm_ops = {
+ .suspend = rcar_usb2_clock_sel_suspend,
+ .resume = rcar_usb2_clock_sel_resume,
+};
+
+static struct platform_driver rcar_usb2_clock_sel_driver = {
+ .driver = {
+ .name = "rcar-usb2-clock-sel",
+ .of_match_table = rcar_usb2_clock_sel_match,
+ .pm = &rcar_usb2_clock_sel_pm_ops,
+ },
+ .probe = rcar_usb2_clock_sel_probe,
+ .remove = rcar_usb2_clock_sel_remove,
+};
+builtin_platform_driver(rcar_usb2_clock_sel_driver);
+
+MODULE_DESCRIPTION("Renesas R-Car USB2 clock selector Driver");
+MODULE_LICENSE("GPL v2");