[U-Boot] [PATCH v2 2/5] usb: host: add error path and remove callback in ehci-generic

[Patrice CHOTARD <patrice.chotard@st.com>]

Hi Marek

On 05/12/2017 10:50 PM, Marek Vasut wrote:
> On 05/12/2017 07:27 PM, patrice.chotard at st.com wrote:
>> From: Patrice Chotard <patrice.chotard@st.com>
>>
>> Add error path to disable enabled clocks and to assert
>> deasserted resets
>> Populate the remove callback
>>
>> Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
>> ---
>> v2:	_ split previous path 1, add error path and .remove callback
>>
>>  drivers/usb/host/ehci-generic.c | 81 +++++++++++++++++++++++++++++++++++------
>>  1 file changed, 70 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/usb/host/ehci-generic.c b/drivers/usb/host/ehci-generic.c
>> index 2190adb..0c29f63 100644
>> --- a/drivers/usb/host/ehci-generic.c
>> +++ b/drivers/usb/host/ehci-generic.c
>> @@ -11,6 +11,9 @@
>>  #include <dm.h>
>>  #include "ehci.h"
>>
>> +#define EHCI_MAX_CLOCKS 3
>> +#define EHCI_MAX_RESETS 3
>
> And then someone invents controller with four resets and this whole
> thing ... breaks.

OK i will use a more generic solution based on list

>
>>  /*
>>   * Even though here we don't explicitly use "struct ehci_ctrl"
>>   * ehci_register() expects it to be the first thing that resides in
>> @@ -18,35 +21,74 @@
>>   */
>>  struct generic_ehci {
>>  	struct ehci_ctrl ctrl;
>> +	struct clk clks[EHCI_MAX_CLOCKS];
>> +	struct reset_ctl resets[EHCI_MAX_RESETS];
>>  };
>>
>> +static void ehci_assert_resets(struct udevice *dev) {
>> +	struct generic_ehci *priv = dev_get_priv(dev);
>> +	struct reset_ctl reset;
>> +	int i;
>> +
>> +	for (i = EHCI_MAX_RESETS; i >= 0; --i) {
>
> Why start from the end ?

Simply to assert resets in reverse order they have been deasserted.
Is it a problematic ?

Thanks

Patrice

>
>> +		reset = priv->resets[i];
>> +
>> +		if (reset.dev) {
>> +                        reset_request(&reset);
>> +                        reset_assert(&reset);
>> +                        reset_free(&reset);
>> +		}
>> +	}
>> +}
>> +
>> +static void ehci_disable_clocks(struct udevice *dev) {
>> +	struct generic_ehci *priv = dev_get_priv(dev);
>> +	struct clk clk;
>> +	int i;
>> +
>> +	for (i = EHCI_MAX_CLOCKS; i >= 0; --i) {
>> +		clk = priv->clks[i];
>> +
>> +		if (clk.dev) {
>> +			clk_request(clk.dev, &clk);
>> +			clk_disable(&clk);
>> +			clk_free(&clk);
>> +		}
>> +	}
>> +}
>> +
>>  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;
>>
>> -	for (i = 0; ; i++) {
>> -		struct clk clk;
>> -		int ret;
>> +	for (i = 0; i < EHCI_MAX_CLOCKS; i++) {
>> +		struct clk clk = priv->clks[i];
>>
>>  		ret = clk_get_by_index(dev, i, &clk);
>>  		if (ret < 0)
>>  			break;
>> -		if (clk_enable(&clk))
>> +		if (clk_enable(&clk)) {
>>  			printf("failed to enable clock %d\n", i);
>> +			clk_free(&clk);
>> +			goto clk_err;
>> +		}
>>  		clk_free(&clk);
>>  	}
>>
>> -	for (i = 0; ; i++) {
>> -		struct reset_ctl reset;
>> -		int ret;
>> +	for (i = 0; i < EHCI_MAX_RESETS ; i++) {
>> +		struct reset_ctl reset = priv->resets[i];
>>
>>  		ret = reset_get_by_index(dev, i, &reset);
>>  		if (ret < 0)
>>  			break;
>> -		if (reset_deassert(&reset))
>> +		if (reset_deassert(&reset)) {
>>  			printf("failed to deassert reset %d\n", i);
>> +			reset_free(&reset);
>> +			goto reset_err;
>> +		}
>>  		reset_free(&reset);
>>  	}
>>
>> @@ -54,7 +96,24 @@ static int ehci_usb_probe(struct udevice *dev)
>>  	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:
>> +	ehci_assert_resets(dev);
>> +clk_err:
>> +	ehci_disable_clocks(dev);
>> +
>> +	return ret;
>> +}
>> +
>> +static int ehci_usb_remove(struct udevice *dev) {
>> +
>> +	ehci_assert_resets(dev);
>> +	ehci_disable_clocks(dev);
>> +
>> +	return ehci_deregister(dev);
>>  }
>>
>>  static const struct udevice_id ehci_usb_ids[] = {
>> @@ -67,7 +126,7 @@ 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,
>>
>
>