dwc3-of-simple.c only handles arbitrary number of clocks and resets.
They are both generic enough to be put into the dwc3 core. For simple
cases, a nested node structure like follows:
dwc3-glue {
compatible = "foo,dwc3";
clocks = ...;
resets = ...;
...
dwc3 {
compatible = "snps,dwc3";
...
};
}
would be turned into a single node:
dwc3 {
compatible = "foo,dwc3", "snps,dwc3";
clocks = ...;
resets = ...;
...
}
I inserted reset_control_deassert() and clk_enable() before the first
register access, i.e. dwc3_cache_hwparams().
Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---
Documentation/devicetree/bindings/usb/dwc3.txt | 2 +
drivers/usb/dwc3/core.c | 127 ++++++++++++++++++++++++-
drivers/usb/dwc3/core.h | 5 +
3 files changed, 132 insertions(+), 2 deletions(-)
diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
index 44e8bab..67e9cfb 100644
--- a/Documentation/devicetree/bindings/usb/dwc3.txt
+++ b/Documentation/devicetree/bindings/usb/dwc3.txt
@@ -9,12 +9,14 @@ Required properties:
- interrupts: Interrupts used by the dwc3 controller.
Optional properties:
+ - clocks: list of phandle and clock specifier pairs
- usb-phy : array of phandle for the PHY device. The first element
in the array is expected to be a handle to the USB2/HS PHY and
the second element is expected to be a handle to the USB3/SS PHY
- phys: from the *Generic PHY* bindings
- phy-names: from the *Generic PHY* bindings; supported names are "usb2-phy"
or "usb3-phy".
+ - resets: list of phandle and reset specifier pairs
- snps,usb3_lpm_capable: determines if platform is USB3 LPM capable
- snps,disable_scramble_quirk: true when SW should disable data scrambling.
Only really useful for FPGA builds.
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index e9083a3..f17e4a9 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -8,6 +8,7 @@
* Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
*/
+#include <linux/clk.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/kernel.h>
@@ -24,6 +25,7 @@
#include <linux/of.h>
#include <linux/acpi.h>
#include <linux/pinctrl/consumer.h>
+#include <linux/reset.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
@@ -240,6 +242,74 @@ static int dwc3_core_soft_reset(struct dwc3 *dwc)
return -ETIMEDOUT;
}
+static int dwc3_core_get_clks(struct dwc3 *dwc)
+{
+ struct device *dev = dwc->dev;
+ struct device_node *node = dev->of_node;
+ struct clk *clk;
+ int num_clks, i;
+
+ num_clks = of_count_phandle_with_args(node, "clocks", "#clock-cells");
+ if (num_clks <= 0)
+ return 0;
+
+ dwc->num_clks = num_clks;
+
+ dwc->clks = devm_kcalloc(dev, num_clks, sizeof(*dwc->clks), GFP_KERNEL);
+ if (!dwc->clks)
+ return -ENOMEM;
+
+ for (i = 0; i < num_clks; i++) {
+ clk = of_clk_get(node, i);
+ if (IS_ERR(clk))
+ goto put_clks;
+ dwc->clks[i] = clk;
+ }
+
+ return 0;
+
+put_clks:
+ while (--i >= 0)
+ clk_put(dwc->clks[i]);
+
+ return PTR_ERR(clk);
+}
+
+static void dwc3_core_put_clks(struct dwc3 *dwc)
+{
+ int i;
+
+ for (i = dwc->num_clks - 1; i >= 0; i--)
+ clk_put(dwc->clks[i]);
+}
+
+static int dwc3_core_enable_clks(struct dwc3 *dwc)
+{
+ int ret, i;
+
+ for (i = 0; i < dwc->num_clks; i++) {
+ ret = clk_prepare_enable(dwc->clks[i]);
+ if (ret)
+ goto disable_clks;
+ }
+
+ return 0;
+
+disable_clks:
+ while (--i >= 0)
+ clk_disable_unprepare(dwc->clks[i]);
+
+ return ret;
+}
+
+static void dwc3_core_disable_clks(struct dwc3 *dwc)
+{
+ int i;
+
+ for (i = dwc->num_clks - 1; i >= 0; i--)
+ clk_disable_unprepare(dwc->clks[i]);
+}
+
/*
* dwc3_frame_length_adjustment - Adjusts frame length if required
* @dwc3: Pointer to our controller context structure
@@ -641,6 +711,8 @@ static void dwc3_core_exit(struct dwc3 *dwc)
usb_phy_set_suspend(dwc->usb3_phy, 1);
phy_power_off(dwc->usb2_generic_phy);
phy_power_off(dwc->usb3_generic_phy);
+ dwc3_core_disable_clks(dwc);
+ reset_control_assert(dwc->resets);
}
static bool dwc3_core_is_valid(struct dwc3 *dwc)
@@ -1205,6 +1277,22 @@ static int dwc3_probe(struct platform_device *pdev)
dwc3_get_properties(dwc);
+ dwc->resets = devm_reset_control_array_get_optional_shared(dev);
+ if (IS_ERR(dwc->resets))
+ return PTR_ERR(dwc->resets);
+
+ ret = dwc3_core_get_clks(dwc);
+ if (ret)
+ return ret;
+
+ ret = reset_control_deassert(dwc->resets);
+ if (ret)
+ goto put_clks;
+
+ ret = dwc3_core_enable_clks(dwc);
+ if (ret)
+ goto assert_resets;
+
platform_set_drvdata(pdev, dwc);
dwc3_cache_hwparams(dwc);
@@ -1268,6 +1356,14 @@ static int dwc3_probe(struct platform_device *pdev)
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
+ dwc3_core_disable_clks(dwc);
+
+assert_resets:
+ reset_control_assert(dwc->resets);
+
+put_clks:
+ dwc3_core_put_clks(dwc);
+
return ret;
}
@@ -1289,11 +1385,38 @@ static int dwc3_remove(struct platform_device *pdev)
dwc3_free_event_buffers(dwc);
dwc3_free_scratch_buffers(dwc);
+ dwc3_core_put_clks(dwc);
return 0;
}
#ifdef CONFIG_PM
+static int dwc3_core_init_for_resume(struct dwc3 *dwc)
+{
+ int ret;
+
+ ret = reset_control_deassert(dwc->resets);
+ if (ret)
+ return ret;
+
+ ret = dwc3_core_enable_clks(dwc);
+ if (ret)
+ goto assert_resets;
+
+ ret = dwc3_core_init(dwc);
+ if (ret)
+ goto disable_clks;
+
+ return 0;
+
+disable_clks:
+ dwc3_core_disable_clks(dwc);
+assert_resets:
+ reset_control_assert(dwc->resets);
+
+ return ret;
+}
+
static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
{
unsigned long flags;
@@ -1325,7 +1448,7 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
switch (dwc->current_dr_role) {
case DWC3_GCTL_PRTCAP_DEVICE:
- ret = dwc3_core_init(dwc);
+ ret = dwc3_core_init_for_resume(dwc);
if (ret)
return ret;
@@ -1336,7 +1459,7 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
case DWC3_GCTL_PRTCAP_HOST:
/* nothing to do on host runtime_resume */
if (!PMSG_IS_AUTO(msg)) {
- ret = dwc3_core_init(dwc);
+ ret = dwc3_core_init_for_resume(dwc);
if (ret)
return ret;
}
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 860d2bc..14cd335 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -891,6 +891,11 @@ struct dwc3 {
struct usb_gadget gadget;
struct usb_gadget_driver *gadget_driver;
+ struct clk **clks;
+ int num_clks;
+
+ struct reset_control *resets;
+
struct usb_phy *usb2_phy;
struct usb_phy *usb3_phy;
--
2.7.4
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