Re: [PATCH 14/21] usb: chipidea: msm: Add proper clk and reset support

Peter Chen
2016-06-29T07:09:14Z

On Sun, Jun 26, 2016 at 12:28:31AM -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 read/write the ULPI phy registers. Some ULPI phys drive
> this clk themselves and so it isn't necessary to turn on to probe
> a ULPI device, but the HSIC phy doesn't provide one itself, so we
> must turn it on here.
>
> 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 | 58 +++++++++++++++++++++++++++++++++++---
> 1 file changed, 54 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/chipidea/ci_hdrc_msm.c b/drivers/usb/chipidea/ci_hdrc_msm.c
> index 07cccd24a87f..40249b0e3e93 100644
> --- a/drivers/usb/chipidea/ci_hdrc_msm.c
> +++ b/drivers/usb/chipidea/ci_hdrc_msm.c
> @@ -10,11 +10,19 @@
> #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;
> +};
> +
> static void ci_hdrc_msm_notify_event(struct ci_hdrc *ci, unsigned event)
> {
> struct device *dev = ci->gadget.dev.parent;
> @@ -43,34 +51,76 @@ 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 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);
> +
> + 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);

You say it has three clocks in commit log, why it is only two in the code?
> +
> + reset_control_assert(reset);
> + usleep_range(10000, 12000);
> + reset_control_deassert(reset);
> +
> + 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);
ci->plat_ci(or ci) = ...

Delete the local variable plat_ci

> 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;

[...]

--

Best Regards,
Peter Chen