diff options
Diffstat (limited to 'drivers/clk/renesas/rcar-usb2-clock-sel.c')
| -rw-r--r-- | drivers/clk/renesas/rcar-usb2-clock-sel.c | 188 |
1 files changed, 188 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 000000000000..6cd030a58964 --- /dev/null +++ b/drivers/clk/renesas/rcar-usb2-clock-sel.c @@ -0,0 +1,188 @@ +/* + * Renesas R-Car USB2.0 clock selector + * + * Copyright (C) 2017 Renesas Electronics Corp. + * + * Based on renesas-cpg-mssr.c + * + * Copyright (C) 2015 Glider bvba + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + */ + +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/device.h> +#include <linux/init.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/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) + +struct usb2_clock_sel_priv { + void __iomem *base; + struct clk_hw hw; + 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) +{ + usb2_clock_sel_enable_extal_only(to_priv(hw)); + + return 0; +} + +static void usb2_clock_sel_disable(struct clk_hw *hw) +{ + usb2_clock_sel_disable_extal_only(to_priv(hw)); +} + +/* + * 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; + struct usb2_clock_sel_priv *priv = platform_get_drvdata(pdev); + + of_clk_del_provider(dev->of_node); + clk_hw_unregister(&priv->hw); + 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 resource *res; + struct clk *clk; + struct clk_init_data init; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + priv->base = devm_ioremap_resource(dev, res); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + pm_runtime_enable(dev); + pm_runtime_get_sync(dev); + + 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; + } + + 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; + + clk = clk_register(NULL, &priv->hw); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + return of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw); +} + +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"); |