[U-Boot] [PATCH v3 3/7] usb: host: ehci-generic: add error path and .remove callback

[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 enabled clocks and deasserted resets
> in order to respectively disabled and asserted them in case of error
> during probe() or during driver removal.
> 
> Signed-off-by: Patrice Chotard <patrice.chotard at st.com>
> ---
> 
> v3:	_ keep enabled clocks and deasserted resets reference in list in order to 
> 	  disable clock or assert resets in error path or in .remove callback
> 	_ use struct generic_ehci * instead of struct udevice * as parameter for
> 	  ehci_release_resets() and ehci_release_clocks()
> 
>  drivers/usb/host/ehci-generic.c | 162 ++++++++++++++++++++++++++++++++++++----
>  1 file changed, 149 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/usb/host/ehci-generic.c b/drivers/usb/host/ehci-generic.c
> index 6058e9a..d281218 100644
> --- a/drivers/usb/host/ehci-generic.c
> +++ b/drivers/usb/host/ehci-generic.c
> @@ -11,6 +11,16 @@
>  #include <dm.h>
>  #include "ehci.h"
>  
> +struct ehci_clock {
> +	struct clk *clk;
> +	struct list_head list;
> +};
> +
> +struct ehci_reset {
> +	struct reset_ctl *reset;
> +	struct list_head list;
> +};
> +
>  /*
>   * Even though here we don't explicitly use "struct ehci_ctrl"
>   * ehci_register() expects it to be the first thing that resides in
> @@ -18,43 +28,169 @@
>   */
>  struct generic_ehci {
>  	struct ehci_ctrl ctrl;
> +	struct list_head clks;
> +	struct list_head resets;
>  };

These functions look so generic that I see no point in not factoring
them out into the clk and reset frameworks respectively.

> +static int ehci_release_resets(struct generic_ehci *priv)
> +{
> +	struct ehci_reset *ehci_reset, *tmp;
> +	struct reset_ctl *reset;
> +	int ret;
> +
> +	list_for_each_entry_safe(ehci_reset, tmp, &priv->resets, list) {
> +		reset = ehci_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(&ehci_reset->list);
> +	}
> +	return 0;
> +}
> +
> +static int ehci_release_clocks(struct generic_ehci *priv)
> +{
> +	struct ehci_clock *ehci_clock, *tmp;
> +	struct clk *clk;
> +	int ret;
> +
> +	list_for_each_entry_safe(ehci_clock, tmp, &priv->clks, list) {
> +		clk = ehci_clock->clk;
> +
> +		clk_request(clk->dev, clk);
> +		if (ret)
> +			return ret;
> +
> +		clk_disable(clk);
> +
> +		ret = clk_free(clk);
> +		if (ret)
> +			return ret;
> +
> +		list_del(&ehci_clock->list);
> +	}
> +	return 0;
> +}
> +
>  static int ehci_usb_probe(struct udevice *dev)
>  {
> +	struct generic_ehci *priv = dev_get_priv(dev);
>  	struct ehci_hccr *hccr;
>  	struct ehci_hcor *hcor;
> -	int i;
> +	int i, ret;
> +
> +	INIT_LIST_HEAD(&priv->clks);
> +	INIT_LIST_HEAD(&priv->resets);
>  
>  	for (i = 0; ; i++) {
> -		struct clk clk;
> -		int ret;
> +		struct ehci_clock *ehci_clock;
> +		struct clk *clk;
>  
> -		ret = clk_get_by_index(dev, i, &clk);
> +		clk = devm_kmalloc(dev, sizeof(*clk), GFP_KERNEL);
> +		if (!clk) {
> +			error("Can't allocate resource\n");
> +			goto clk_err;
> +		}
> +
> +		ret = clk_get_by_index(dev, i, clk);
>  		if (ret < 0)
>  			break;
> -		if (clk_enable(&clk))
> +
> +		if (clk_enable(clk)) {
>  			error("failed to enable clock %d\n", i);
> -		clk_free(&clk);
> +			clk_free(clk);
> +			goto clk_err;
> +		}
> +		clk_free(clk);
> +
> +		/*
> +		 * add enabled clocks into clks list in order to be disabled
> +		 * later on ehci_usb_remove() call or in error path if needed
> +		 */
> +		ehci_clock = devm_kmalloc(dev, sizeof(*ehci_clock), GFP_KERNEL);
> +		if (!ehci_clock) {
> +			error("Can't allocate resource\n");
> +			goto clk_err;
> +		}
> +		ehci_clock->clk = clk;
> +		list_add(&ehci_clock->list, &priv->clks);
>  	}
>  
>  	for (i = 0; ; i++) {
> -		struct reset_ctl reset;
> -		int ret;
> +		struct ehci_reset *ehci_reset;
> +		struct reset_ctl *reset;
> +
> +		reset = devm_kmalloc(dev, sizeof(*reset), GFP_KERNEL);
> +		if (!reset) {
> +			error("Can't allocate resource\n");
> +			goto clk_err;
> +		}
>  
> -		ret = reset_get_by_index(dev, i, &reset);
> +		ret = reset_get_by_index(dev, i, reset);
>  		if (ret < 0)
>  			break;
> -		if (reset_deassert(&reset))
> +
> +		if (reset_deassert(reset)) {
>  			error("failed to deassert reset %d\n", i);
> -		reset_free(&reset);
> +			reset_free(reset);
> +			goto reset_err;
> +		}
> +		reset_free(reset);
> +
> +		/*
> +		 * add deasserted resets into resets list in order to be
> +		 * asserted later on ehci_usb_remove() call or in error
> +		 * path if needed
> +		 */
> +		ehci_reset = devm_kmalloc(dev, sizeof(*ehci_reset), GFP_KERNEL);
> +		if (!ehci_reset) {
> +			error("Can't allocate resource\n");
> +			goto reset_err;
> +		}
> +		ehci_reset->reset = reset;
> +		list_add(&ehci_reset->list, &priv->resets);
>  	}
>  
>  	hccr = map_physmem(dev_get_addr(dev), 0x100, MAP_NOCACHE);
>  	hcor = (struct ehci_hcor *)((uintptr_t)hccr +
>  				    HC_LENGTH(ehci_readl(&hccr->cr_capbase)));
>  
> -	return ehci_register(dev, hccr, hcor, NULL, 0, USB_INIT_HOST);
> +	ret = ehci_register(dev, hccr, hcor, NULL, 0, USB_INIT_HOST);
> +	if (!ret)
> +		return ret;
> +
> +reset_err:
> +	ret = ehci_release_resets(priv);
> +	if (ret)
> +		return ret;
> +clk_err:
> +	return ehci_release_clocks(priv);
> +}
> +
> +static int ehci_usb_remove(struct udevice *dev)
> +{
> +	struct generic_ehci *priv = dev_get_priv(dev);
> +	int ret;
> +
> +	ret = ehci_deregister(dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = ehci_release_resets(priv);
> +	if (ret)
> +		return ret;
> +
> +	return ehci_release_clocks(priv);
>  }
>  
>  static const struct udevice_id ehci_usb_ids[] = {
> @@ -67,7 +203,7 @@ U_BOOT_DRIVER(ehci_generic) = {
>  	.id	= UCLASS_USB,
>  	.of_match = ehci_usb_ids,
>  	.probe = ehci_usb_probe,
> -	.remove = ehci_deregister,
> +	.remove = ehci_usb_remove,
>  	.ops	= &ehci_usb_ops,
>  	.priv_auto_alloc_size = sizeof(struct generic_ehci),
>  	.flags	= DM_FLAG_ALLOC_PRIV_DMA,
> 


-- 
Best regards,
Marek Vasut