diff mbox

[RESEND,v5,1/5] usb: host: ehci-st: Add EHCI support for ST STB devices

Message ID 1409937829-23708-2-git-send-email-peter.griffin@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Peter Griffin Sept. 5, 2014, 5:23 p.m. UTC
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@linaro.org>
---
 drivers/usb/host/ehci-st.c       | 365 +++++++++++++++++++++++++++++++++++++++
 drivers/usb/host/usb-st-common.h |  31 ++++
 2 files changed, 396 insertions(+)
 create mode 100644 drivers/usb/host/ehci-st.c
 create mode 100644 drivers/usb/host/usb-st-common.h

Comments

Arnd Bergmann Sept. 5, 2014, 5:57 p.m. UTC | #1
On Friday 05 September 2014 18:23:45 Peter Griffin wrote:
> +struct st_platform_priv {
> +       struct clk *clks[USB_MAX_CLKS];
> +       struct clk *clk48;
> +       struct reset_control *rst;
> +       struct reset_control *pwr;
> +       struct phy *phy;
> +};

Any reason why this is in a shared header file? It looks like
duplicating the structure under two different names would
actually be shorter and keep the drivers more readable as they'd
be self-contained, even when they have the exact same structure.

Do both drivers use all fields?

	Arnd
Peter Griffin Sept. 5, 2014, 6:16 p.m. UTC | #2
Hi Arnd,

On Fri, 05 Sep 2014, Arnd Bergmann wrote:

> On Friday 05 September 2014 18:23:45 Peter Griffin wrote:
> > +struct st_platform_priv {
> > +       struct clk *clks[USB_MAX_CLKS];
> > +       struct clk *clk48;
> > +       struct reset_control *rst;
> > +       struct reset_control *pwr;
> > +       struct phy *phy;
> > +};
> 
> Any reason why this is in a shared header file? It looks like
> duplicating the structure under two different names would
> actually be shorter and keep the drivers more readable as they'd
> be self-contained, even when they have the exact same structure.

The only reason was it was a identical structure so I put it in a shared
header file. I can unabstract it if you want?

> 
> Do both drivers use all fields?

Yes they are. I thought the 48Mhz clock would only be used by ohci, but annoyingly it also
clocks the reset logic of the ehci block as well.

regards,

Peter.
Arnd Bergmann Sept. 5, 2014, 6:30 p.m. UTC | #3
On Friday 05 September 2014 19:16:36 Peter Griffin wrote:
> On Fri, 05 Sep 2014, Arnd Bergmann wrote:
> 
> > On Friday 05 September 2014 18:23:45 Peter Griffin wrote:
> > > +struct st_platform_priv {
> > > +       struct clk *clks[USB_MAX_CLKS];
> > > +       struct clk *clk48;
> > > +       struct reset_control *rst;
> > > +       struct reset_control *pwr;
> > > +       struct phy *phy;
> > > +};
> > 
> > Any reason why this is in a shared header file? It looks like
> > duplicating the structure under two different names would
> > actually be shorter and keep the drivers more readable as they'd
> > be self-contained, even when they have the exact same structure.
> 
> The only reason was it was a identical structure so I put it in a shared
> header file. I can unabstract it if you want?

Yes, I think that would be an improvement. Everything looks great to me
otherwise, at least after a brief look.

	Arnd
diff mbox

Patch

diff --git a/drivers/usb/host/ehci-st.c b/drivers/usb/host/ehci-st.c
new file mode 100644
index 0000000..c363807
--- /dev/null
+++ b/drivers/usb/host/ehci-st.c
@@ -0,0 +1,365 @@ 
+/*
+ * ST EHCI driver
+ *
+ * Copyright (C) 2014 STMicroelectronics – All Rights Reserved
+ *
+ * Author: Peter Griffin <peter.griffin@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"
+#include "usb-st-common.h"
+
+#define DRIVER_DESC "EHCI STMicroelectronics driver"
+
+#define hcd_to_ehci_priv(h) ((struct st_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_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_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_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_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_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@linaro.org>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/usb/host/usb-st-common.h b/drivers/usb/host/usb-st-common.h
new file mode 100644
index 0000000..da67402
--- /dev/null
+++ b/drivers/usb/host/usb-st-common.h
@@ -0,0 +1,31 @@ 
+/*
+ * ST ehci / ohci common header file
+ *
+ * Copyright (C) 2014 STMicroelectronics – All Rights Reserved
+ *
+ * Author: Peter Griffin <peter.griffin@linaro.org>
+ *
+ * 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.
+ *
+ */
+
+#ifndef __USB_ST_COMMON_H
+#define __USB_ST_COMMON_H
+
+#include <linux/clk.h>
+#include <linux/reset.h>
+#include <linux/phy/phy.h>
+
+#define USB_MAX_CLKS 3
+
+struct st_platform_priv {
+	struct clk *clks[USB_MAX_CLKS];
+	struct clk *clk48;
+	struct reset_control *rst;
+	struct reset_control *pwr;
+	struct phy *phy;
+};
+
+#endif /* __USB_ST_COMMON_H */