| // 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 void 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); |
| } |
| |
| 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_shared(dev); |
| 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; |
| 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_new = 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"); |