[PATCH v6 1/5] usb: host: ehci-st: Add EHCI support for ST STB devices
Peter Griffin
peter.griffin at linaro.org
Mon Sep 8 05:04:44 PDT 2014
This patch adds the glue code required to ensure the on-chip EHCI
controller works on STi consumer electronics SoC's from STMicroelectronics.
It mainly manages the setting and enabling of the relevant clocks and manages
the reset / power signals to the IP block.
Signed-off-by: Peter Griffin <peter.griffin at linaro.org>
---
drivers/usb/host/ehci-st.c | 375 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 375 insertions(+)
create mode 100644 drivers/usb/host/ehci-st.c
diff --git a/drivers/usb/host/ehci-st.c b/drivers/usb/host/ehci-st.c
new file mode 100644
index 0000000..7e4bd39
--- /dev/null
+++ b/drivers/usb/host/ehci-st.c
@@ -0,0 +1,375 @@
+/*
+ * ST EHCI driver
+ *
+ * Copyright (C) 2014 STMicroelectronics – All Rights Reserved
+ *
+ * Author: Peter Griffin <peter.griffin at linaro.org>
+ *
+ * Derived from ehci-platform.c
+ *
+ * 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/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/hrtimer.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/ehci_pdriver.h>
+
+#include "ehci.h"
+
+#define USB_MAX_CLKS 3
+
+struct st_ehci_platform_priv {
+ struct clk *clks[USB_MAX_CLKS];
+ struct clk *clk48;
+ struct reset_control *rst;
+ struct reset_control *pwr;
+ struct phy *phy;
+};
+
+#define DRIVER_DESC "EHCI STMicroelectronics driver"
+
+#define hcd_to_ehci_priv(h) \
+ ((struct st_ehci_platform_priv *)hcd_to_ehci(h)->priv)
+
+static const char hcd_name[] = "ehci-st";
+
+#define EHCI_CAPS_SIZE 0x10
+#define AHB2STBUS_INSREG01 (EHCI_CAPS_SIZE + 0x84)
+
+static int st_ehci_platform_reset(struct usb_hcd *hcd)
+{
+ struct platform_device *pdev = to_platform_device(hcd->self.controller);
+ struct usb_ehci_pdata *pdata = dev_get_platdata(&pdev->dev);
+ struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+ int retval;
+ u32 threshold;
+
+ /* Set EHCI packet buffer IN/OUT threshold to 128 bytes */
+ threshold = 128 | (128 << 16);
+ writel(threshold, hcd->regs + AHB2STBUS_INSREG01);
+
+ ehci->caps = hcd->regs + pdata->caps_offset;
+ retval = ehci_setup(hcd);
+ if (retval)
+ return retval;
+
+ return 0;
+}
+
+static int st_ehci_platform_power_on(struct platform_device *dev)
+{
+ struct usb_hcd *hcd = platform_get_drvdata(dev);
+ struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
+ int clk, ret;
+
+ ret = reset_control_deassert(priv->pwr);
+ if (ret)
+ return ret;
+
+ ret = reset_control_deassert(priv->rst);
+ if (ret)
+ goto err_assert_power;
+
+ /* some SoCs don't have a dedicated 48Mhz clock, but those that do
+ need the rate to be explicitly set */
+ if (priv->clk48) {
+ ret = clk_set_rate(priv->clk48, 48000000);
+ if (ret)
+ goto err_assert_reset;
+ }
+
+ for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++) {
+ ret = clk_prepare_enable(priv->clks[clk]);
+ if (ret)
+ goto err_disable_clks;
+ }
+
+ ret = phy_init(priv->phy);
+ if (ret)
+ goto err_disable_clks;
+
+ ret = phy_power_on(priv->phy);
+ if (ret)
+ goto err_exit_phy;
+
+ return 0;
+
+err_exit_phy:
+ phy_exit(priv->phy);
+err_disable_clks:
+ while (--clk >= 0)
+ clk_disable_unprepare(priv->clks[clk]);
+err_assert_reset:
+ reset_control_assert(priv->rst);
+err_assert_power:
+ reset_control_assert(priv->pwr);
+
+ return ret;
+}
+
+static void st_ehci_platform_power_off(struct platform_device *dev)
+{
+ struct usb_hcd *hcd = platform_get_drvdata(dev);
+ struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
+ int clk;
+
+ reset_control_assert(priv->pwr);
+
+ reset_control_assert(priv->rst);
+
+ phy_power_off(priv->phy);
+
+ phy_exit(priv->phy);
+
+ for (clk = USB_MAX_CLKS - 1; clk >= 0; clk--)
+ if (priv->clks[clk])
+ clk_disable_unprepare(priv->clks[clk]);
+
+}
+
+static struct hc_driver __read_mostly ehci_platform_hc_driver;
+
+static const struct ehci_driver_overrides platform_overrides __initconst = {
+ .reset = st_ehci_platform_reset,
+ .extra_priv_size = sizeof(struct st_ehci_platform_priv),
+};
+
+static struct usb_ehci_pdata ehci_platform_defaults = {
+ .power_on = st_ehci_platform_power_on,
+ .power_suspend = st_ehci_platform_power_off,
+ .power_off = st_ehci_platform_power_off,
+};
+
+static int st_ehci_platform_probe(struct platform_device *dev)
+{
+ struct usb_hcd *hcd;
+ struct resource *res_mem;
+ struct usb_ehci_pdata *pdata = &ehci_platform_defaults;
+ struct st_ehci_platform_priv *priv;
+ struct ehci_hcd *ehci;
+ int err, irq, clk = 0;
+
+ if (usb_disabled())
+ return -ENODEV;
+
+ irq = platform_get_irq(dev, 0);
+ if (irq < 0) {
+ dev_err(&dev->dev, "no irq provided");
+ return irq;
+ }
+ res_mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ if (!res_mem) {
+ dev_err(&dev->dev, "no memory resource provided");
+ return -ENXIO;
+ }
+
+ hcd = usb_create_hcd(&ehci_platform_hc_driver, &dev->dev,
+ dev_name(&dev->dev));
+ if (!hcd)
+ return -ENOMEM;
+
+ platform_set_drvdata(dev, hcd);
+ dev->dev.platform_data = pdata;
+ priv = hcd_to_ehci_priv(hcd);
+ ehci = hcd_to_ehci(hcd);
+
+ priv->phy = devm_phy_get(&dev->dev, "usb");
+ if (IS_ERR(priv->phy)) {
+ err = PTR_ERR(priv->phy);
+ goto err_put_hcd;
+ }
+
+ for (clk = 0; clk < USB_MAX_CLKS; clk++) {
+ priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
+ if (IS_ERR(priv->clks[clk])) {
+ err = PTR_ERR(priv->clks[clk]);
+ if (err == -EPROBE_DEFER)
+ goto err_put_clks;
+ priv->clks[clk] = NULL;
+ break;
+ }
+ }
+
+ /* some SoCs don't have a dedicated 48Mhz clock, but those that
+ do need the rate to be explicitly set */
+ priv->clk48 = devm_clk_get(&dev->dev, "clk48");
+ if (IS_ERR(priv->clk48)) {
+ dev_info(&dev->dev, "48MHz clk not found\n");
+ priv->clk48 = NULL;
+ }
+
+ priv->pwr = devm_reset_control_get_optional(&dev->dev, "power");
+ if (IS_ERR(priv->pwr)) {
+ err = PTR_ERR(priv->pwr);
+ if (err == -EPROBE_DEFER)
+ goto err_put_clks;
+ priv->pwr = NULL;
+ }
+
+ priv->rst = devm_reset_control_get_optional(&dev->dev, "softreset");
+ if (IS_ERR(priv->rst)) {
+ err = PTR_ERR(priv->rst);
+ if (err == -EPROBE_DEFER)
+ goto err_put_clks;
+ priv->rst = NULL;
+ }
+
+ if (pdata->power_on) {
+ err = pdata->power_on(dev);
+ if (err < 0)
+ goto err_put_clks;
+ }
+
+ hcd->rsrc_start = res_mem->start;
+ hcd->rsrc_len = resource_size(res_mem);
+
+ hcd->regs = devm_ioremap_resource(&dev->dev, res_mem);
+ if (IS_ERR(hcd->regs)) {
+ err = PTR_ERR(hcd->regs);
+ goto err_put_clks;
+ }
+
+ err = usb_add_hcd(hcd, irq, IRQF_SHARED);
+ if (err)
+ goto err_put_clks;
+
+ device_wakeup_enable(hcd->self.controller);
+ platform_set_drvdata(dev, hcd);
+
+ return err;
+
+err_put_clks:
+ while (--clk >= 0)
+ clk_put(priv->clks[clk]);
+err_put_hcd:
+ if (pdata == &ehci_platform_defaults)
+ dev->dev.platform_data = NULL;
+
+ usb_put_hcd(hcd);
+
+ return err;
+}
+
+static int st_ehci_platform_remove(struct platform_device *dev)
+{
+ struct usb_hcd *hcd = platform_get_drvdata(dev);
+ struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
+ struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
+ int clk;
+
+ usb_remove_hcd(hcd);
+
+ if (pdata->power_off)
+ pdata->power_off(dev);
+
+ for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++)
+ clk_put(priv->clks[clk]);
+
+ usb_put_hcd(hcd);
+
+ if (pdata == &ehci_platform_defaults)
+ dev->dev.platform_data = NULL;
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int st_ehci_suspend(struct device *dev)
+{
+ struct usb_hcd *hcd = dev_get_drvdata(dev);
+ struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
+ struct platform_device *pdev =
+ container_of(dev, struct platform_device, dev);
+ bool do_wakeup = device_may_wakeup(dev);
+ int ret;
+
+ ret = ehci_suspend(hcd, do_wakeup);
+ if (ret)
+ return ret;
+
+ if (pdata->power_suspend)
+ pdata->power_suspend(pdev);
+
+ pinctrl_pm_select_sleep_state(dev);
+
+ return ret;
+}
+
+static int st_ehci_resume(struct device *dev)
+{
+ struct usb_hcd *hcd = dev_get_drvdata(dev);
+ struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
+ struct platform_device *pdev =
+ container_of(dev, struct platform_device, dev);
+ int err;
+
+ pinctrl_pm_select_default_state(dev);
+
+ if (pdata->power_on) {
+ err = pdata->power_on(pdev);
+ if (err < 0)
+ return err;
+ }
+
+ ehci_resume(hcd, false);
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(st_ehci_pm_ops, st_ehci_suspend, st_ehci_resume);
+
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct of_device_id st_ehci_ids[] = {
+ { .compatible = "st,st-ehci-300x", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, st_ehci_ids);
+
+static struct platform_driver ehci_platform_driver = {
+ .probe = st_ehci_platform_probe,
+ .remove = st_ehci_platform_remove,
+ .shutdown = usb_hcd_platform_shutdown,
+ .driver = {
+ .name = "st-ehci",
+#ifdef CONFIG_PM_SLEEP
+ .pm = &st_ehci_pm_ops,
+#endif
+ .of_match_table = st_ehci_ids,
+ }
+};
+
+static int __init ehci_platform_init(void)
+{
+ if (usb_disabled())
+ return -ENODEV;
+
+ pr_info("%s: " DRIVER_DESC "\n", hcd_name);
+
+ ehci_init_driver(&ehci_platform_hc_driver, &platform_overrides);
+ return platform_driver_register(&ehci_platform_driver);
+}
+module_init(ehci_platform_init);
+
+static void __exit ehci_platform_cleanup(void)
+{
+ platform_driver_unregister(&ehci_platform_driver);
+}
+module_exit(ehci_platform_cleanup);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Peter Griffin <peter.griffin at linaro.org>");
+MODULE_LICENSE("GPL");
--
1.9.1
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