[PATCH v1 5/8] usb: chipidea: tegra: Support host mode

Dmitry Osipenko
2020-12-15T20:24:04Z

From: Peter Geis <pgwipeout@gmail.com>

Add USB host mode to the Tegra HDRC driver. This allows us to benefit from
support provided by the generic ChipIdea driver instead of duplicating the
effort in a separate ehci-terga driver.

Tested-by: Matt Merhar <mattmerhar@protonmail.com>
Tested-by: Nicolas Chauvet <kwizart@gmail.com>
Signed-off-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/usb/chipidea/Kconfig | 1 -
drivers/usb/chipidea/ci_hdrc_tegra.c | 243 ++++++++++++++++++++++++++-
drivers/usb/chipidea/core.c | 10 +-
drivers/usb/chipidea/host.c | 103 +++++++++++-
include/linux/usb/chipidea.h | 6 +
5 files changed, 355 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
index 8685ead6ccc7..661818e8fed6 100644
--- a/drivers/usb/chipidea/Kconfig
+++ b/drivers/usb/chipidea/Kconfig
@@ -55,7 +55,6 @@ config USB_CHIPIDEA_GENERIC
config USB_CHIPIDEA_TEGRA
tristate "Enable Tegra USB glue driver" if EMBEDDED
depends on OF
- depends on USB_CHIPIDEA_UDC
default USB_CHIPIDEA

endif
diff --git a/drivers/usb/chipidea/ci_hdrc_tegra.c b/drivers/usb/chipidea/ci_hdrc_tegra.c
index d8efa80aa1c2..fff130f08996 100644
--- a/drivers/usb/chipidea/ci_hdrc_tegra.c
+++ b/drivers/usb/chipidea/ci_hdrc_tegra.c
@@ -4,11 +4,18 @@
*/

#include <linux/clk.h>
+#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/reset.h>

+#include <linux/usb.h>
#include <linux/usb/chipidea.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/of.h>
+#include <linux/usb/phy.h>
+
+#include "../host/ehci.h"

#include "ci.h"

@@ -16,20 +23,47 @@ struct tegra_usb {
struct ci_hdrc_platform_data data;
struct platform_device *dev;

+ const struct tegra_usb_soc_info *soc;
struct usb_phy *phy;
struct clk *clk;
+
+ bool needs_double_reset;
};

struct tegra_usb_soc_info {
unsigned long flags;
+ unsigned int txfifothresh;
+ enum usb_dr_mode dr_mode;
+};
+
+static const struct tegra_usb_soc_info tegra20_ehci_soc_info = {
+ .flags = CI_HDRC_REQUIRES_ALIGNED_DMA |
+ CI_HDRC_OVERRIDE_PHY_CONTROL,
+ .dr_mode = USB_DR_MODE_HOST,
+ .txfifothresh = 10,
+};
+
+static const struct tegra_usb_soc_info tegra30_ehci_soc_info = {
+ .flags = CI_HDRC_REQUIRES_ALIGNED_DMA |
+ CI_HDRC_OVERRIDE_PHY_CONTROL
+ .dr_mode = USB_DR_MODE_HOST,
+ .txfifothresh = 16,
};

static const struct tegra_usb_soc_info tegra_udc_soc_info = {
- .flags = CI_HDRC_REQUIRES_ALIGNED_DMA,
+ .flags = CI_HDRC_REQUIRES_ALIGNED_DMA |
+ CI_HDRC_OVERRIDE_PHY_CONTROL,
+ .dr_mode = USB_DR_MODE_UNKNOWN,
};

static const struct of_device_id tegra_usb_of_match[] = {
{
+ .compatible = "nvidia,tegra20-ehci",
+ .data = &tegra20_ehci_soc_info,
+ }, {
+ .compatible = "nvidia,tegra30-ehci",
+ .data = &tegra30_ehci_soc_info,
+ }, {
.compatible = "nvidia,tegra20-udc",
.data = &tegra_udc_soc_info,
}, {
@@ -47,6 +81,181 @@ static const struct of_device_id tegra_usb_of_match[] = {
};
MODULE_DEVICE_TABLE(of, tegra_usb_of_match);

+static int tegra_usb_reset_controller(struct device *dev)
+{
+ struct reset_control *rst, *rst_utmi;
+ struct device_node *phy_np;
+ int err;
+
+ rst = devm_reset_control_get_shared(dev, "usb");
+ if (IS_ERR(rst)) {
+ dev_err(dev, "can't get ehci reset: %pe\n", rst);
+ return PTR_ERR(rst);
+ }
+
+ phy_np = of_parse_phandle(dev->of_node, "nvidia,phy", 0);
+ if (!phy_np)
+ return -ENOENT;
+
+ /*
+ * The 1st USB controller contains some UTMI pad registers that are
+ * global for all the controllers on the chip. Those registers are
+ * also cleared when reset is asserted to the 1st controller.
+ */
+ rst_utmi = of_reset_control_get_shared(phy_np, "utmi-pads");
+ if (IS_ERR(rst_utmi)) {
+ dev_warn(dev, "can't get utmi-pads reset from the PHY\n");
+ dev_warn(dev, "continuing, but please update your DT\n");
+ } else {
+ /*
+ * PHY driver performs UTMI-pads reset in a case of a
+ * non-legacy DT.
+ */
+ reset_control_put(rst_utmi);
+ }
+
+ of_node_put(phy_np);
+
+ /* reset control is shared, hence initialize it first */
+ err = reset_control_deassert(rst);
+ if (err)
+ return err;
+
+ err = reset_control_assert(rst);
+ if (err)
+ return err;
+
+ udelay(1);
+
+ err = reset_control_deassert(rst);
+ if (err)
+ return err;
+
+ return 0;
+}
+
+static int tegra_usb_notify_event(struct ci_hdrc *ci, unsigned int event)
+{
+ struct tegra_usb *usb = dev_get_drvdata(ci->dev->parent);
+ struct ehci_hcd *ehci;
+
+ switch (event) {
+ case CI_HDRC_CONTROLLER_RESET_EVENT:
+ if (ci->hcd) {
+ ehci = hcd_to_ehci(ci->hcd);
+ ehci->has_tdi_phy_lpm = false;
+ ehci_writel(ehci, usb->soc->txfifothresh << 16,
+ &ehci->regs->txfill_tuning);
+ }
+ break;
+ }
+
+ return 0;
+}
+
+static int tegra_usb_internal_port_reset(struct ehci_hcd *ehci,
+ u32 __iomem *portsc_reg,
+ unsigned long *flags)
+{
+ u32 saved_usbintr, temp;
+ unsigned int i, tries;
+ int retval = 0;
+
+ saved_usbintr = ehci_readl(ehci, &ehci->regs->intr_enable);
+ /* disable USB interrupt */
+ ehci_writel(ehci, 0, &ehci->regs->intr_enable);
+ spin_unlock_irqrestore(&ehci->lock, *flags);
+
+ /*
+ * Here we have to do Port Reset at most twice for
+ * Port Enable bit to be set.
+ */
+ for (i = 0; i < 2; i++) {
+ temp = ehci_readl(ehci, portsc_reg);
+ temp |= PORT_RESET;
+ ehci_writel(ehci, temp, portsc_reg);
+ mdelay(10);
+ temp &= ~PORT_RESET;
+ ehci_writel(ehci, temp, portsc_reg);
+ mdelay(1);
+ tries = 100;
+ do {
+ mdelay(1);
+ /*
+ * Up to this point, Port Enable bit is
+ * expected to be set after 2 ms waiting.
+ * USB1 usually takes extra 45 ms, for safety,
+ * we take 100 ms as timeout.
+ */
+ temp = ehci_readl(ehci, portsc_reg);
+ } while (!(temp & PORT_PE) && tries--);
+ if (temp & PORT_PE)
+ break;
+ }
+ if (i == 2)
+ retval = -ETIMEDOUT;
+
+ /*
+ * Clear Connect Status Change bit if it's set.
+ * We can't clear PORT_PEC. It will also cause PORT_PE to be cleared.
+ */
+ if (temp & PORT_CSC)
+ ehci_writel(ehci, PORT_CSC, portsc_reg);
+
+ /*
+ * Write to clear any interrupt status bits that might be set
+ * during port reset.
+ */
+ temp = ehci_readl(ehci, &ehci->regs->status);
+ ehci_writel(ehci, temp, &ehci->regs->status);
+
+ /* restore original interrupt-enable bits */
+ spin_lock_irqsave(&ehci->lock, *flags);
+ ehci_writel(ehci, saved_usbintr, &ehci->regs->intr_enable);
+
+ return retval;
+}
+
+static int tegra_ehci_hub_control(struct ci_hdrc *ci, u16 typeReq, u16 wValue,
+ u16 wIndex, char *buf, u16 wLength,
+ bool *done, unsigned long *flags)
+{
+ struct tegra_usb *usb = dev_get_drvdata(ci->dev->parent);
+ struct ehci_hcd *ehci = hcd_to_ehci(ci->hcd);
+ u32 __iomem *status_reg;
+ int retval = 0;
+
+ status_reg = &ehci->regs->port_status[(wIndex & 0xff) - 1];
+
+ switch (typeReq) {
+ case SetPortFeature:
+ if (wValue != USB_PORT_FEAT_RESET || !usb->needs_double_reset)
+ break;
+
+ /* for USB1 port we need to issue Port Reset twice internally */
+ retval = tegra_usb_internal_port_reset(ehci, status_reg, flags);
+ *done = true;
+ break;
+ }
+
+ return retval;
+}
+
+static void tegra_usb_enter_lpm(struct ci_hdrc *ci, bool enable)
+{
+ /*
+ * Touching any register which belongs to AHB clock domain will
+ * hang CPU if USB controller is put into low power mode because
+ * AHB USB clock is gated on Tegra in the LPM.
+ *
+ * Tegra PHY has a separate register for checking the clock status
+ * and usb_phy_set_suspend() takes care of gating/ungating the clocks
+ * and restoring the PHY state on Tegra. Hence DEVLC/PORTSC registers
+ * shouldn't be touched directly by the CI driver.
+ */
+ usb_phy_set_suspend(ci->usb_phy, enable);
+}
+
static int tegra_usb_probe(struct platform_device *pdev)
{
const struct tegra_usb_soc_info *soc;
@@ -83,24 +292,49 @@ static int tegra_usb_probe(struct platform_device *pdev)
return err;
}

+ if (device_property_present(&pdev->dev, "nvidia,needs-double-reset"))
+ usb->needs_double_reset = true;
+
+ err = tegra_usb_reset_controller(&pdev->dev);
+ if (err) {
+ dev_err(&pdev->dev, "failed to reset controller: %d\n", err);
+ goto fail_power_off;
+ }
+
+ /*
+ * USB controller registers shan't be touched before PHY is
+ * initialized, otherwise CPU will hang because clocks are gated.
+ * PHY driver controls gating of internal USB clocks on Tegra.
+ */
+ err = usb_phy_init(usb->phy);
+ if (err)
+ goto fail_power_off;
+
+ platform_set_drvdata(pdev, usb);
+
/* setup and register ChipIdea HDRC device */
+ usb->soc = soc;
usb->data.name = "tegra-usb";
usb->data.flags = soc->flags;
usb->data.usb_phy = usb->phy;
+ usb->data.dr_mode = soc->dr_mode;
usb->data.capoffset = DEF_CAPOFFSET;
+ usb->data.enter_lpm = tegra_usb_enter_lpm;
+ usb->data.hub_control = tegra_ehci_hub_control;
+ usb->data.notify_event = tegra_usb_notify_event;

usb->dev = ci_hdrc_add_device(&pdev->dev, pdev->resource,
pdev->num_resources, &usb->data);
if (IS_ERR(usb->dev)) {
err = PTR_ERR(usb->dev);
dev_err(&pdev->dev, "failed to add HDRC device: %d\n", err);
- goto fail_power_off;
+ goto phy_shutdown;
}

- platform_set_drvdata(pdev, usb);
-
return 0;

+phy_shutdown:
+ usb_phy_shutdown(usb->phy);
fail_power_off:
clk_disable_unprepare(usb->clk);
return err;
@@ -111,6 +345,7 @@ static int tegra_usb_remove(struct platform_device *pdev)
struct tegra_usb *usb = platform_get_drvdata(pdev);

ci_hdrc_remove_device(usb->dev);
+ usb_phy_shutdown(usb->phy);
clk_disable_unprepare(usb->clk);

return 0;
diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index aa40e510b806..3f6c21406dbd 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -195,7 +195,7 @@ static void hw_wait_phy_stable(void)
}

/* The PHY enters/leaves low power mode */
-static void ci_hdrc_enter_lpm(struct ci_hdrc *ci, bool enable)
+static void ci_hdrc_enter_lpm_common(struct ci_hdrc *ci, bool enable)
{
enum ci_hw_regs reg = ci->hw_bank.lpm ? OP_DEVLC : OP_PORTSC;
bool lpm = !!(hw_read(ci, reg, PORTSC_PHCD(ci->hw_bank.lpm)));
@@ -208,6 +208,11 @@ static void ci_hdrc_enter_lpm(struct ci_hdrc *ci, bool enable)
0);
}

+static void ci_hdrc_enter_lpm(struct ci_hdrc *ci, bool enable)
+{
+ return ci->platdata->enter_lpm(ci, enable);
+}
+
static int hw_device_init(struct ci_hdrc *ci, void __iomem *base)
{
u32 reg;
@@ -790,6 +795,9 @@ static int ci_get_platdata(struct device *dev,
platdata->pins_device = p;
}

+ if (!platdata->enter_lpm)
+ platdata->enter_lpm = ci_hdrc_enter_lpm_common;
+
return 0;
}

diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
index 48e4a5ca1835..b8a4c44ab580 100644
--- a/drivers/usb/chipidea/host.c
+++ b/drivers/usb/chipidea/host.c
@@ -29,6 +29,12 @@ struct ehci_ci_priv {
bool enabled;
};

+struct ci_hdrc_dma_aligned_buffer {
+ void *kmalloc_ptr;
+ void *old_xfer_buffer;
+ u8 data[0];
+};
+
static int ehci_ci_portpower(struct usb_hcd *hcd, int portnum, bool enable)
{
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
@@ -160,14 +166,14 @@ static int host_start(struct ci_hdrc *ci)
pinctrl_select_state(ci->platdata->pctl,
ci->platdata->pins_host);

+ ci->hcd = hcd;
+
ret = usb_add_hcd(hcd, 0, 0);
if (ret) {
goto disable_reg;
} else {
struct usb_otg *otg = &ci->otg;

- ci->hcd = hcd;
-
if (ci_otg_is_fsm_mode(ci)) {
otg->host = &hcd->self;
hcd->self.otg_port = 1;
@@ -237,6 +243,7 @@ static int ci_ehci_hub_control(
u32 temp;
unsigned long flags;
int retval = 0;
+ bool done = false;
struct device *dev = hcd->self.controller;
struct ci_hdrc *ci = dev_get_drvdata(dev);

@@ -244,6 +251,13 @@ static int ci_ehci_hub_control(

spin_lock_irqsave(&ehci->lock, flags);

+ if (ci->platdata->hub_control) {
+ retval = ci->platdata->hub_control(ci, typeReq, wValue, wIndex,
+ buf, wLength, &done, &flags);
+ if (done)
+ goto done;
+ }
+
if (typeReq == SetPortFeature && wValue == USB_PORT_FEAT_SUSPEND) {
temp = ehci_readl(ehci, status_reg);
if ((temp & PORT_PE) == 0 || (temp & PORT_RESET) != 0) {
@@ -349,6 +363,86 @@ static int ci_ehci_bus_suspend(struct usb_hcd *hcd)
return 0;
}

+static void ci_hdrc_free_dma_aligned_buffer(struct urb *urb)
+{
+ struct ci_hdrc_dma_aligned_buffer *temp;
+ size_t length;
+
+ if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
+ return;
+
+ temp = container_of(urb->transfer_buffer,
+ struct ci_hdrc_dma_aligned_buffer, data);
+
+ if (usb_urb_dir_in(urb)) {
+ if (usb_pipeisoc(urb->pipe))
+ length = urb->transfer_buffer_length;
+ else
+ length = urb->actual_length;
+
+ memcpy(temp->old_xfer_buffer, temp->data, length);
+ }
+ urb->transfer_buffer = temp->old_xfer_buffer;
+ kfree(temp->kmalloc_ptr);
+
+ urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
+}
+
+static int ci_hdrc_alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags)
+{
+ struct ci_hdrc_dma_aligned_buffer *temp, *kmalloc_ptr;
+ const unsigned int ci_hdrc_usb_dma_align = 32;
+ size_t kmalloc_size;
+
+ if (urb->num_sgs || urb->sg || urb->transfer_buffer_length == 0 ||
+ !((uintptr_t)urb->transfer_buffer & (ci_hdrc_usb_dma_align - 1)))
+ return 0;
+
+ /* Allocate a buffer with enough padding for alignment */
+ kmalloc_size = urb->transfer_buffer_length +
+ sizeof(struct ci_hdrc_dma_aligned_buffer) +
+ ci_hdrc_usb_dma_align - 1;
+
+ kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
+ if (!kmalloc_ptr)
+ return -ENOMEM;
+
+ /* Position our struct dma_aligned_buffer such that data is aligned */
+ temp = PTR_ALIGN(kmalloc_ptr + 1, ci_hdrc_usb_dma_align) - 1;
+ temp->kmalloc_ptr = kmalloc_ptr;
+ temp->old_xfer_buffer = urb->transfer_buffer;
+ if (usb_urb_dir_out(urb))
+ memcpy(temp->data, urb->transfer_buffer,
+ urb->transfer_buffer_length);
+ urb->transfer_buffer = temp->data;
+
+ urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;
+
+ return 0;
+}
+
+static int ci_hdrc_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
+ gfp_t mem_flags)
+{
+ int ret;
+
+ ret = ci_hdrc_alloc_dma_aligned_buffer(urb, mem_flags);
+ if (ret)
+ return ret;
+
+ ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
+ if (ret)
+ ci_hdrc_free_dma_aligned_buffer(urb);
+
+ return ret;
+}
+
+static void ci_hdrc_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
+{
+ usb_hcd_unmap_urb_for_dma(hcd, urb);
+ ci_hdrc_free_dma_aligned_buffer(urb);
+}
+
int ci_hdrc_host_init(struct ci_hdrc *ci)
{
struct ci_role_driver *rdrv;
@@ -366,6 +460,11 @@ int ci_hdrc_host_init(struct ci_hdrc *ci)
rdrv->name = "host";
ci->roles[CI_ROLE_HOST] = rdrv;

+ if (ci->platdata->flags & CI_HDRC_REQUIRES_ALIGNED_DMA) {
+ ci_ehci_hc_driver.map_urb_for_dma = ci_hdrc_map_urb_for_dma;
+ ci_ehci_hc_driver.unmap_urb_for_dma = ci_hdrc_unmap_urb_for_dma;
+ }
+
return 0;
}

diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h
index 025b41687ce9..edf3342507f1 100644
--- a/include/linux/usb/chipidea.h
+++ b/include/linux/usb/chipidea.h
@@ -88,6 +88,12 @@ struct ci_hdrc_platform_data {
struct pinctrl_state *pins_default;
struct pinctrl_state *pins_host;
struct pinctrl_state *pins_device;
+
+ /* platform-specific hooks */
+ int (*hub_control)(struct ci_hdrc *ci, u16 typeReq, u16 wValue,
+ u16 wIndex, char *buf, u16 wLength,
+ bool *done, unsigned long *flags);
+ void (*enter_lpm)(struct ci_hdrc *ci, bool enable);
};

/* Default offset of capability registers */
--
2.29.2