[U-Boot] [PATCH v3 6/7] usb: host: ohci-generic: add RESET support

[Marek Vasut]

On 05/17/2017 03:34 PM, patrice.chotard at st.com wrote:
> From: Patrice Chotard <patrice.chotard at st.com>
> 
> use list to save reference to deasserted resets in order to
> assert them in case of error during probe() or during driver
> removal.
> 
> Signed-off-by: Patrice Chotard <patrice.chotard at st.com>
> ---
> 
> v3:	_ extract in this patch the RESET support add-on from previous patch 5
> 	_ keep deassrted resets reference in list in order to 
> 	  assert resets in error path or in .remove callback
> 
> v2:	_ add error path management
> 	_ add .remove callback
> 
>  drivers/usb/host/ohci-generic.c | 78 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 78 insertions(+)
> 
> diff --git a/drivers/usb/host/ohci-generic.c b/drivers/usb/host/ohci-generic.c
> index a6d89a8..bf14ab7 100644
> --- a/drivers/usb/host/ohci-generic.c
> +++ b/drivers/usb/host/ohci-generic.c
> @@ -7,6 +7,7 @@
>  #include <common.h>
>  #include <clk.h>
>  #include <dm.h>
> +#include <reset.h>
>  #include "ohci.h"
>  
>  #if !defined(CONFIG_USB_OHCI_NEW)
> @@ -18,11 +19,43 @@ struct ohci_clock {
>  	struct list_head list;
>  };
>  
> +struct ohci_reset {
> +	struct reset_ctl *reset;
> +	struct list_head list;
> +};
> +
>  struct generic_ohci {
>  	ohci_t ohci;
>  	struct list_head clks;
> +	struct list_head resets;
>  };
>  
> +static int ohci_release_resets(struct generic_ohci *priv)
> +{
> +	struct ohci_reset *ohci_reset, *tmp;
> +	struct reset_ctl *reset;
> +	int ret;
> +
> +	list_for_each_entry_safe(ohci_reset, tmp, &priv->resets, list) {
> +		reset = ohci_reset->reset;
> +
> +		ret = reset_request(reset);
> +		if (ret)
> +			return ret;
> +
> +		ret = reset_assert(reset);
> +		if (ret)
> +			return ret;
> +
> +		ret = reset_free(reset);
> +		if (ret)
> +			return ret;
> +
> +		list_del(&(ohci_reset->list));
> +	}
> +	return 0;
> +}
> +
>  static int ohci_release_clocks(struct generic_ohci *priv)
>  {
>  	struct ohci_clock *ohci_clock, *tmp;
> @@ -54,6 +87,7 @@ static int ohci_usb_probe(struct udevice *dev)
>  	int i, ret;
>  
>  	INIT_LIST_HEAD(&priv->clks);
> +	INIT_LIST_HEAD(&priv->resets);
>  
>  	for (i = 0; ; i++) {
>  		struct ohci_clock *ohci_clock;
> @@ -89,8 +123,48 @@ static int ohci_usb_probe(struct udevice *dev)
>  		list_add(&ohci_clock->list, &priv->clks);
>  	}
>  
> +	for (i = 0; ; i++) {
> +		struct ohci_reset *ohci_reset;
> +		struct reset_ctl *reset;
> +
> +		reset = devm_kmalloc(dev, sizeof(*reset), GFP_KERNEL);

Same comment as on 5/7

> +		if (!reset) {
> +			error("Can't allocate resource\n");
> +			goto clk_err;
> +		}
> +
> +		ret = reset_get_by_index(dev, i, reset);
> +		if (ret < 0)
> +			break;
> +
> +		if (reset_deassert(reset)) {
> +			error("failed to deassert reset %d\n", i);
> +			reset_free(reset);
> +			goto reset_err;
> +		}
> +		reset_free(reset);
> +
> +		/*
> +		 * add deasserted resets into resets list in order to be
> +		 * asserted later on ohci_usb_remove() call or in error
> +		 * path if needed
> +		 */
> +		ohci_reset = devm_kmalloc(dev, sizeof(*ohci_reset), GFP_KERNEL);
> +		if (!ohci_reset) {
> +			error("Can't allocate resource\n");
> +			goto reset_err;
> +		}
> +		ohci_reset->reset = reset;
> +		list_add(&ohci_reset->list, &priv->resets);
> +	}
> +
> +
>  	return ohci_register(dev, regs);
>  
> +reset_err:
> +	ret = ohci_release_resets(priv);
> +	if (ret)
> +		return ret;
>  clk_err:
>  	return ohci_release_clocks(priv);
>  }
> @@ -104,6 +178,10 @@ static int ohci_usb_remove(struct udevice *dev)
>  	if (ret)
>  		return ret;
>  
> +	ret = ohci_release_resets(priv);
> +	if (ret)
> +		return ret;
> +
>  	return ohci_release_clocks(priv);
>  }
>  
> 


-- 
Best regards,
Marek Vasut