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Message-Id: <20180316112851.d70521f05c79951a6d300742@kernel.org>
Date: Fri, 16 Mar 2018 11:28:51 +0900
From: Masami Hiramatsu <mhiramat@...nel.org>
To: Masahiro Yamada <yamada.masahiro@...ionext.com>
Cc: Felipe Balbi <felipe.balbi@...ux.intel.com>,
linux-usb@...r.kernel.org, Masami Hiramatsu <mhiramat@...nel.org>,
Jassi Brar <jaswinder.singh@...aro.org>,
Kunihiko Hayashi <hayashi.kunihiko@...ionext.com>,
devicetree@...r.kernel.org, Felipe Balbi <balbi@...nel.org>,
linux-kernel@...r.kernel.org, Rob Herring <robh+dt@...nel.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Mark Rutland <mark.rutland@....com>
Subject: Re: [PATCH 2/2] usb: dwc3: add clock and resets
On Thu, 15 Mar 2018 20:39:58 +0900
Masahiro Yamada <yamada.masahiro@...ionext.com> wrote:
> 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().
This looks good to me.
Reviewed-by: Masami Hiramatsu <mhiramat@...nel.org>
Thanks!
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@...ionext.com>
> ---
>
> 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@...utronix.de>
> */
>
> +#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
>
--
Masami Hiramatsu <mhiramat@...nel.org>
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