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SubjectRe: [PATCH v2 14/22] usb: chipidea: msm: Add proper clk and reset support
On Thu, Jul 07, 2016 at 03:21:05PM -0700, Stephen Boyd wrote:
> The msm chipidea controller uses two main clks, an AHB clk to
> read/write the MMIO registers and a core clk called the system
> clk that drives the controller itself. Add support for these clks
> as they're required in all designs.
>
> Also add support for an optional third clk that we need to turn
> on to reset the controller and wrapper logic and other
> "housekeeping" things. This clk was removed in later revisions of
> the hardware because the reset methodology no longer required
> clks to be enabled to propagate resets.
>
> Cc: Peter Chen <peter.chen@nxp.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
> ---
> drivers/usb/chipidea/ci_hdrc_msm.c | 72 +++++++++++++++++++++++++++++++++++---
> 1 file changed, 68 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/chipidea/ci_hdrc_msm.c b/drivers/usb/chipidea/ci_hdrc_msm.c
> index b282a717bf8c..7e870a253f55 100644
> --- a/drivers/usb/chipidea/ci_hdrc_msm.c
> +++ b/drivers/usb/chipidea/ci_hdrc_msm.c
> @@ -10,11 +10,20 @@
> #include <linux/pm_runtime.h>
> #include <linux/usb/gadget.h>
> #include <linux/usb/chipidea.h>
> +#include <linux/clk.h>
> +#include <linux/reset.h>
>
> #include "ci.h"
>
> #define HS_PHY_AHB_MODE 0x0098
>
> +struct ci_hdrc_msm {
> + struct platform_device *ci;
> + struct clk *core_clk;
> + struct clk *iface_clk;
> + struct clk *fs_clk;
> +};
> +
> static void ci_hdrc_msm_notify_event(struct ci_hdrc *ci, unsigned event)
> {
> struct device *dev = ci->gadget.dev.parent;
> @@ -52,11 +61,20 @@ static struct ci_hdrc_platform_data ci_hdrc_msm_platdata = {
>
> static int ci_hdrc_msm_probe(struct platform_device *pdev)
> {
> + struct ci_hdrc_msm *ci;
> struct platform_device *plat_ci;
> struct usb_phy *phy;
> + struct clk *clk;
> + struct reset_control *reset;
> + int ret;
>
> dev_dbg(&pdev->dev, "ci_hdrc_msm_probe\n");
>
> + ci = devm_kzalloc(&pdev->dev, sizeof(*ci), GFP_KERNEL);
> + if (!ci)
> + return -ENOMEM;
> + platform_set_drvdata(pdev, ci);
> +
> /*
> * OTG(PHY) driver takes care of PHY initialization, clock management,
> * powering up VBUS, mapping of registers address space and power
> @@ -68,29 +86,75 @@ static int ci_hdrc_msm_probe(struct platform_device *pdev)
>
> ci_hdrc_msm_platdata.usb_phy = phy;
>
> + reset = devm_reset_control_get(&pdev->dev, "core");
> + if (IS_ERR(reset))
> + return PTR_ERR(reset);
> +
> + ci->core_clk = clk = devm_clk_get(&pdev->dev, "core");
> + if (IS_ERR(clk))
> + return PTR_ERR(clk);
> +
> + ci->iface_clk = clk = devm_clk_get(&pdev->dev, "iface");
> + if (IS_ERR(clk))
> + return PTR_ERR(clk);
> +
> + ci->fs_clk = clk = devm_clk_get(&pdev->dev, "fs");
> + if (IS_ERR(clk)) {
> + if (PTR_ERR(clk) == -EPROBE_DEFER)
> + return -EPROBE_DEFER;
> + ci->fs_clk = NULL;
> + }
> +
> + ret = clk_prepare_enable(ci->fs_clk);
> + if (ret)
> + return ret;
> +
> + reset_control_assert(reset);
> + usleep_range(10000, 12000);
> + reset_control_deassert(reset);
> +
> + clk_disable_unprepare(ci->fs_clk);
> +
> + ret = clk_prepare_enable(ci->core_clk);
> + if (ret)
> + return ret;
> +
> + ret = clk_prepare_enable(ci->iface_clk);
> + if (ret)
> + goto err_iface;
> +
> plat_ci = ci_hdrc_add_device(&pdev->dev,
> pdev->resource, pdev->num_resources,
> &ci_hdrc_msm_platdata);
> if (IS_ERR(plat_ci)) {
> dev_err(&pdev->dev, "ci_hdrc_add_device failed!\n");
> - return PTR_ERR(plat_ci);
> + ret = PTR_ERR(plat_ci);
> + goto err_mux;
> }
>
> - platform_set_drvdata(pdev, plat_ci);
> + ci->ci = plat_ci;
>
> pm_runtime_set_active(&pdev->dev);
> pm_runtime_no_callbacks(&pdev->dev);
> pm_runtime_enable(&pdev->dev);
>
> return 0;
> +
> +err_mux:
> + clk_disable_unprepare(ci->iface_clk);
> +err_iface:
> + clk_disable_unprepare(ci->core_clk);
> + return ret;
> }
>
> static int ci_hdrc_msm_remove(struct platform_device *pdev)
> {
> - struct platform_device *plat_ci = platform_get_drvdata(pdev);
> + struct ci_hdrc_msm *ci = platform_get_drvdata(pdev);
>
> pm_runtime_disable(&pdev->dev);
> - ci_hdrc_remove_device(plat_ci);
> + ci_hdrc_remove_device(ci->ci);
> + clk_disable_unprepare(ci->iface_clk);
> + clk_disable_unprepare(ci->core_clk);
>
> return 0;
> }
> --

Acked-by: Peter Chen <peter.chen@nxp.com>

--

Best Regards,
Peter Chen

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