On Wed, 2017-02-22 at 10:54 +0530, Vivek Gautam wrote:
> Add support to get a list of resets available for the device.
> These resets must be kept de-asserted until the device is
> in use.
>
> Cc: Felipe Balbi <ba...@kernel.org>
> Signed-off-by: Vivek Gautam <vivek.gau...@codeaurora.org>
> ---
>
> Based on torvald's master branch.
>
> drivers/usb/dwc3/dwc3-of-simple.c | 49
> +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 49 insertions(+)
>
> diff --git a/drivers/usb/dwc3/dwc3-of-simple.c
> b/drivers/usb/dwc3/dwc3-of-simple.c
> index fe414e7a9c78..025de7342d28 100644
> --- a/drivers/usb/dwc3/dwc3-of-simple.c
> +++ b/drivers/usb/dwc3/dwc3-of-simple.c
> @@ -29,13 +29,52 @@
> #include <linux/of.h>
> #include <linux/of_platform.h>
> #include <linux/pm_runtime.h>
> +#include <linux/reset.h>
>
> struct dwc3_of_simple {
> struct device *dev;
> struct clk **clks;
> int num_clocks;
> + struct reset_control **resets;
> + int num_resets;
> };
>
> +static int dwc3_of_simple_reset_init(struct dwc3_of_simple *simple, int
> count)
> +{
> + struct device *dev = simple->dev;
> + int i;
> +
> + simple->num_resets = count;
> +
> + if (!count)
> + return 0;
> +
> + simple->resets = devm_kcalloc(dev, simple->num_resets,
> + sizeof(struct reset_control *), GFP_KERNEL);
> + if (!simple->resets)
> + return -ENOMEM;
> +
> + for (i = 0; i < simple->num_resets; i++) {
> + struct reset_control *reset;
> + int ret;
> +
> + reset = devm_reset_control_get_by_index(dev, i);
Please use devm_reset_control_get_exclusive_by_index instead. See
include/linux/reset.h for details.
> + if (IS_ERR(reset))
> + return PTR_ERR(reset);
> +
> + simple->resets[i] = reset;
> +
> + ret = reset_control_deassert(reset);
> + if (ret) {
> + while (--i >= 0)
> + reset_control_assert(reset);
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
This looks rather generic. Should we have a
reset_control_get/assert/deassert_array functionality at the reset API
level?
> static int dwc3_of_simple_clk_init(struct dwc3_of_simple *simple, int count)
> {
> struct device *dev = simple->dev;
> @@ -100,6 +139,10 @@ static int dwc3_of_simple_probe(struct platform_device
> *pdev)
> if (ret)
> return ret;
>
> + ret = dwc3_of_simple_reset_init(simple, of_reset_control_get_count(np));
> + if (ret)
> + return ret;
> +
Not a blocker, but it seems a bit inconsistent to count the reset
controls via the device node (of_...), but then get them via the device
(devm_reset_control_get_... instead of of_reset_control_get_...).
regards
Philipp
