[U-Boot] [PATCH v3 5/7] usb: host: ohci-generic: add CLOCK 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 enabled clocks in order to
> disabled 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 CLOCK support add-on from previous patch 5
> 	_ keep enabled clocks reference in list in order to 
> 	  disable clocks in error path or in .remove callback
> 
> v2:	_ add error path management
> 	_ add .remove callback
> 
>  drivers/usb/host/ohci-generic.c | 81 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 80 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/host/ohci-generic.c b/drivers/usb/host/ohci-generic.c
> index f3307f4..a6d89a8 100644
> --- a/drivers/usb/host/ohci-generic.c
> +++ b/drivers/usb/host/ohci-generic.c
> @@ -5,6 +5,7 @@
>   */
>  
>  #include <common.h>
> +#include <clk.h>
>  #include <dm.h>
>  #include "ohci.h"
>  
> @@ -12,20 +13,98 @@
>  # error "Generic OHCI driver requires CONFIG_USB_OHCI_NEW"
>  #endif
>  
> +struct ohci_clock {
> +	struct clk *clk;
> +	struct list_head list;
> +};
> +
>  struct generic_ohci {
>  	ohci_t ohci;
> +	struct list_head clks;
>  };
>  
> +static int ohci_release_clocks(struct generic_ohci *priv)
> +{
> +	struct ohci_clock *ohci_clock, *tmp;
> +	struct clk *clk;
> +	int ret;
> +
> +	list_for_each_entry_safe(ohci_clock, tmp, &priv->clks, list) {
> +		clk = ohci_clock->clk;
> +
> +		clk_request(clk->dev, clk);
> +		if (ret)
> +			return ret;
> +
> +		clk_disable(clk);
> +
> +		ret = clk_free(clk);
> +		if (ret)
> +			return ret;
> +
> +		list_del(&ohci_clock->list);
> +	}
> +	return 0;
> +}
> +
>  static int ohci_usb_probe(struct udevice *dev)
>  {
>  	struct ohci_regs *regs = (struct ohci_regs *)dev_get_addr(dev);
> +	struct generic_ohci *priv = dev_get_priv(dev);
> +	int i, ret;
> +
> +	INIT_LIST_HEAD(&priv->clks);
> +
> +	for (i = 0; ; i++) {
> +		struct ohci_clock *ohci_clock;
> +		struct clk *clk;
> +
> +		clk = devm_kmalloc(dev, sizeof(*clk), GFP_KERNEL);

Since you know how many entries the clock phandle has, you can allocate
an array and drop this while list handling and this per-element kmalloc,
which fragments the allocator pool.

> +		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)) {
> +			error("failed to enable ohci_clock %d\n", i);
> +			clk_free(clk);
> +			goto clk_err;
> +		}
> +		clk_free(clk);
> +
> +		/*
> +		 * add enabled clocks into clks list in order to be disabled
> +		 * later on ohci_usb_remove() call or in error path if needed
> +		 */
> +		ohci_clock = devm_kmalloc(dev, sizeof(*ohci_clock), GFP_KERNEL);

Can't you just embed one structure into the other ?

> +		if (!ohci_clock) {
> +			error("Can't allocate resource\n");
> +			goto clk_err;
> +		}
> +		ohci_clock->clk = clk;
> +		list_add(&ohci_clock->list, &priv->clks);
> +	}
>  
>  	return ohci_register(dev, regs);
> +
> +clk_err:
> +	return ohci_release_clocks(priv);
>  }
>  
>  static int ohci_usb_remove(struct udevice *dev)
>  {
> -	return ohci_deregister(dev);
> +	struct generic_ohci *priv = dev_get_priv(dev);
> +	int ret;
> +
> +	ret = ohci_deregister(dev);
> +	if (ret)
> +		return ret;
> +
> +	return ohci_release_clocks(priv);
>  }
>  
>  static const struct udevice_id ohci_usb_ids[] = {
> 


-- 
Best regards,
Marek Vasut