Re: [PATCH linux-next v2 1/1] usb: gadget: udc: atmel: Update endpoint allocation scheme

From: Nicolas Ferre
Date: Thu Jan 26 2017 - 10:02:36 EST

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Le 23/01/2017 à 15:45, cristian.birsan@xxxxxxxxxxxxx a écrit :
> From: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>
>
> Update atmel udc driver with a new enpoint allocation scheme. The data
> sheet requires that all endpoints are allocated in order.

Pieces of information from the cover letter could have been added here.

> Signed-off-by: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>
> ---
> drivers/usb/gadget/udc/Kconfig | 14 ++
> drivers/usb/gadget/udc/atmel_usba_udc.c | 236 +++++++++++++++++++++++++++-----
> drivers/usb/gadget/udc/atmel_usba_udc.h | 10 +-
> 3 files changed, 227 insertions(+), 33 deletions(-)

It can be good to run ./scripts/checkpatch.pl --strict as well. It would
have told you about some of the alignment and braces issues. I ran it as
some the code has looked weird to me once or twice...

> diff --git a/drivers/usb/gadget/udc/Kconfig b/drivers/usb/gadget/udc/Kconfig
> index 658b8da..4b69f28 100644
> --- a/drivers/usb/gadget/udc/Kconfig
> +++ b/drivers/usb/gadget/udc/Kconfig
> @@ -60,6 +60,20 @@ config USB_ATMEL_USBA
> USBA is the integrated high-speed USB Device controller on
> the AT32AP700x, some AT91SAM9 and AT91CAP9 processors from Atmel.
>
> + The fifo_mode parameter is used to select endpoint allocation mode.
> + fifo_mode = 0 is used to let the driver autoconfigure the endpoints.
> + In this case 2 banks are allocated for isochronous endpoints and

You mean that 2 banks can do isochronous xfers if needed, but they can
do other types as well, right? So maybe rephrase the sentence.

> + only one bank is allocated for the rest of the endpoints.
> +
> + fifo_mode = 1 is a generic maximum fifo size (1024 bytes) configuration
> + allowing the usage of ep1 - ep6
> +
> + fifo_mode = 2 is a generic performance maximum fifo size (1024 bytes)
> + configuration allowing the usage of ep1 - ep3
> +
> + fifo_mode = 3 is a balanced performance configuration allowing the
> + the usage of ep1 - ep8
> +
> config USB_BCM63XX_UDC
> tristate "Broadcom BCM63xx Peripheral Controller"
> depends on BCM63XX
> diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
> index 12c7687..11bbce2 100644
> --- a/drivers/usb/gadget/udc/atmel_usba_udc.c
> +++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
> @@ -20,6 +20,7 @@
> #include <linux/mfd/syscon.h>
> #include <linux/platform_device.h>
> #include <linux/regmap.h>
> +#include <linux/ctype.h>
> #include <linux/usb/ch9.h>
> #include <linux/usb/gadget.h>
> #include <linux/usb/atmel_usba_udc.h>
> @@ -318,6 +319,91 @@ static inline void usba_cleanup_debugfs(struct usba_udc *udc)
> }
> #endif
>
> +static ushort fifo_mode;
> +
> +/* "modprobe ... fifo_mode=1" etc */

No need for this comment.

> +module_param(fifo_mode, ushort, 0x0);
> +MODULE_PARM_DESC(fifo_mode, "Endpoint configuration mode");
> +
> +/* mode 0 - uses autoconfig */
> +
> +/* mode 1 - fits in 8KB, generic max fifo configuration */
> +static struct usba_fifo_cfg mode_1_cfg[] = {
> +{ .hw_ep_num = 0, .fifo_size = 64, .nr_banks = 1, },
> +{ .hw_ep_num = 1, .fifo_size = 1024, .nr_banks = 2, },
> +{ .hw_ep_num = 2, .fifo_size = 1024, .nr_banks = 1, },
> +{ .hw_ep_num = 3, .fifo_size = 1024, .nr_banks = 1, },
> +{ .hw_ep_num = 4, .fifo_size = 1024, .nr_banks = 1, },
> +{ .hw_ep_num = 5, .fifo_size = 1024, .nr_banks = 1, },
> +{ .hw_ep_num = 6, .fifo_size = 1024, .nr_banks = 1, },
> +};
> +
> +/* mode 2 - fits in 8KB, performance max fifo configuration */
> +static struct usba_fifo_cfg mode_2_cfg[] = {
> +{ .hw_ep_num = 0, .fifo_size = 64, .nr_banks = 1, },
> +{ .hw_ep_num = 1, .fifo_size = 1024, .nr_banks = 3, },
> +{ .hw_ep_num = 2, .fifo_size = 1024, .nr_banks = 2, },
> +{ .hw_ep_num = 3, .fifo_size = 1024, .nr_banks = 2, },
> +};
> +
> +/* mode 3 - fits in 8KB, mixed fifo configuration */
> +static struct usba_fifo_cfg mode_3_cfg[] = {
> +{ .hw_ep_num = 0, .fifo_size = 64, .nr_banks = 1, },
> +{ .hw_ep_num = 1, .fifo_size = 1024, .nr_banks = 2, },
> +{ .hw_ep_num = 2, .fifo_size = 512, .nr_banks = 2, },
> +{ .hw_ep_num = 3, .fifo_size = 512, .nr_banks = 2, },
> +{ .hw_ep_num = 4, .fifo_size = 512, .nr_banks = 2, },
> +{ .hw_ep_num = 5, .fifo_size = 512, .nr_banks = 2, },
> +{ .hw_ep_num = 6, .fifo_size = 512, .nr_banks = 2, },
> +};
> +
> +/* mode 4 - fits in 8KB, custom fifo configuration */
> +static struct usba_fifo_cfg mode_4_cfg[] = {
> +{ .hw_ep_num = 0, .fifo_size = 64, .nr_banks = 1, },
> +{ .hw_ep_num = 1, .fifo_size = 512, .nr_banks = 2, },
> +{ .hw_ep_num = 2, .fifo_size = 512, .nr_banks = 2, },
> +{ .hw_ep_num = 3, .fifo_size = 8, .nr_banks = 2, },
> +{ .hw_ep_num = 4, .fifo_size = 512, .nr_banks = 2, },
> +{ .hw_ep_num = 5, .fifo_size = 512, .nr_banks = 2, },
> +{ .hw_ep_num = 6, .fifo_size = 16, .nr_banks = 2, },
> +{ .hw_ep_num = 7, .fifo_size = 8, .nr_banks = 2, },
> +{ .hw_ep_num = 8, .fifo_size = 8, .nr_banks = 2, },
> +};
> +/* Add additional configurations here */
> +
> +int usba_config_fifo_table(struct usba_udc *udc)

Isn't is static?

> +{
> + int n;
> +
> + switch (fifo_mode) {
> + default:
> + fifo_mode = 0;
> + case 0:
> + udc->fifo_cfg = NULL;
> + n = 0;
> + break;
> + case 1:
> + udc->fifo_cfg = mode_1_cfg;
> + n = ARRAY_SIZE(mode_1_cfg);
> + break;
> + case 2:
> + udc->fifo_cfg = mode_2_cfg;
> + n = ARRAY_SIZE(mode_2_cfg);
> + break;
> + case 3:
> + udc->fifo_cfg = mode_3_cfg;
> + n = ARRAY_SIZE(mode_3_cfg);
> + break;
> + case 4:
> + udc->fifo_cfg = mode_4_cfg;
> + n = ARRAY_SIZE(mode_4_cfg);
> + break;
> + }
> + DBG(DBG_HW, "Setup fifo_mode %d\n", fifo_mode);
> +
> + return n;
> +}
> +
> static inline u32 usba_int_enb_get(struct usba_udc *udc)
> {
> return udc->int_enb_cache;
> @@ -543,24 +629,17 @@ usba_ep_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
> ep->is_isoc = 0;
> ep->is_in = 0;
>
> - if (maxpacket <= 8)
> - ept_cfg = USBA_BF(EPT_SIZE, USBA_EPT_SIZE_8);
> - else
> - /* LSB is bit 1, not 0 */
> - ept_cfg = USBA_BF(EPT_SIZE, fls(maxpacket - 1) - 3);
> -
> - DBG(DBG_HW, "%s: EPT_SIZE = %lu (maxpacket = %lu)\n",
> + DBG(DBG_ERR, "%s: EPT_CFG = 0x%lx (maxpacket = %lu)\n",
> ep->ep.name, ept_cfg, maxpacket);
>
> if (usb_endpoint_dir_in(desc)) {
> ep->is_in = 1;
> - ept_cfg |= USBA_EPT_DIR_IN;
> + ep->ept_cfg |= USBA_EPT_DIR_IN;
> }
>
> switch (usb_endpoint_type(desc)) {
> case USB_ENDPOINT_XFER_CONTROL:
> - ept_cfg |= USBA_BF(EPT_TYPE, USBA_EPT_TYPE_CONTROL);
> - ept_cfg |= USBA_BF(BK_NUMBER, USBA_BK_NUMBER_ONE);
> + ep->ept_cfg |= USBA_BF(EPT_TYPE, USBA_EPT_TYPE_CONTROL);
> break;
> case USB_ENDPOINT_XFER_ISOC:
> if (!ep->can_isoc) {
> @@ -578,24 +657,15 @@ usba_ep_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
> return -EINVAL;
>
> ep->is_isoc = 1;
> - ept_cfg |= USBA_BF(EPT_TYPE, USBA_EPT_TYPE_ISO);
> + ep->ept_cfg |= USBA_BF(EPT_TYPE, USBA_EPT_TYPE_ISO);
> + ep->ept_cfg |= USBA_BF(NB_TRANS, nr_trans);
>
> - /*
> - * Do triple-buffering on high-bandwidth iso endpoints.
> - */
> - if (nr_trans > 1 && ep->nr_banks == 3)
> - ept_cfg |= USBA_BF(BK_NUMBER, USBA_BK_NUMBER_TRIPLE);
> - else
> - ept_cfg |= USBA_BF(BK_NUMBER, USBA_BK_NUMBER_DOUBLE);
> - ept_cfg |= USBA_BF(NB_TRANS, nr_trans);
> break;
> case USB_ENDPOINT_XFER_BULK:
> - ept_cfg |= USBA_BF(EPT_TYPE, USBA_EPT_TYPE_BULK);
> - ept_cfg |= USBA_BF(BK_NUMBER, USBA_BK_NUMBER_DOUBLE);
> + ep->ept_cfg |= USBA_BF(EPT_TYPE, USBA_EPT_TYPE_BULK);
> break;
> case USB_ENDPOINT_XFER_INT:
> - ept_cfg |= USBA_BF(EPT_TYPE, USBA_EPT_TYPE_INT);
> - ept_cfg |= USBA_BF(BK_NUMBER, USBA_BK_NUMBER_DOUBLE);
> + ep->ept_cfg |= USBA_BF(EPT_TYPE, USBA_EPT_TYPE_INT);
> break;
> }
>
> @@ -604,7 +674,7 @@ usba_ep_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
> ep->ep.desc = desc;
> ep->ep.maxpacket = maxpacket;
>
> - usba_ep_writel(ep, CFG, ept_cfg);
> + usba_ep_writel(ep, CFG, ep->ept_cfg);
> usba_ep_writel(ep, CTL_ENB, USBA_EPT_ENABLE);
>
> if (ep->can_dma) {
> @@ -1006,12 +1076,81 @@ static int atmel_usba_start(struct usb_gadget *gadget,
> struct usb_gadget_driver *driver);
> static int atmel_usba_stop(struct usb_gadget *gadget);
>
> +static struct usb_ep *atmel_usba_match_ep(

I find the indentation of this funciton wreird...

> + struct usb_gadget *gadget,

No need for a tab here and align with open parenthesis,

> + struct usb_endpoint_descriptor *desc,
> + struct usb_ss_ep_comp_descriptor *ep_comp
> +)

This parenthesis seems weird to me: put it after the last parameter.

> +{
> + struct usb_ep *_ep;
> + struct usba_ep *ep;
> +
> + /* Look at endpoints until an unclaimed one looks usable */
> + list_for_each_entry(_ep, &gadget->ep_list, ep_list) {
> + if (usb_gadget_ep_match_desc(gadget, _ep, desc, ep_comp))
> + goto found_ep;
> + }
> + /* Fail */
> + return NULL;
> +
> +found_ep:
> +
> + if (fifo_mode == 0) {
> + /* Optimize hw fifo size based on ep type and other info */
> + ep = to_usba_ep(_ep);
> +
> + switch (usb_endpoint_type(desc)) {
> +
> + case USB_ENDPOINT_XFER_CONTROL:
> + break;
> +
> + case USB_ENDPOINT_XFER_ISOC:
> + ep->fifo_size = 1024;
> + ep->nr_banks = 2;
> + break;
> +
> + case USB_ENDPOINT_XFER_BULK:
> + ep->fifo_size = 512;
> + ep->nr_banks = 1;
> + break;
> +
> + case USB_ENDPOINT_XFER_INT:
> + if (desc->wMaxPacketSize == 0)
> + ep->fifo_size =
> + roundup_pow_of_two(_ep->maxpacket_limit);
> + else
> + ep->fifo_size =
> + roundup_pow_of_two(le16_to_cpu(desc->wMaxPacketSize));
> + ep->nr_banks = 1;
> + break;
> + }
> +
> + /* It might be a little bit late to set this */

Is it too late or not? This comment is frightening... We may need some
feedback from the USB guys here...

> + usb_ep_set_maxpacket_limit(&ep->ep, ep->fifo_size);
> +
> + /* Generate ept_cfg basd on FIFO size and number of banks */
> + if (ep->fifo_size <= 8)
> + ep->ept_cfg = USBA_BF(EPT_SIZE, USBA_EPT_SIZE_8);
> + else
> + /* LSB is bit 1, not 0 */
> + ep->ept_cfg =
> + USBA_BF(EPT_SIZE, fls(ep->fifo_size - 1) - 3);
> +
> + ep->ept_cfg |= USBA_BF(BK_NUMBER, ep->nr_banks);
> + ep->udc->configured_ep++;

is it more than a boolean value?

> + }
> +
> +return _ep;

Indentation issue here ^

> +}
> +
> static const struct usb_gadget_ops usba_udc_ops = {
> .get_frame = usba_udc_get_frame,
> .wakeup = usba_udc_wakeup,
> .set_selfpowered = usba_udc_set_selfpowered,
> .udc_start = atmel_usba_start,
> .udc_stop = atmel_usba_stop,
> + .match_ep = atmel_usba_match_ep,
> };
>
> static struct usb_endpoint_descriptor usba_ep0_desc = {
> @@ -1678,7 +1817,8 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
> }
>
> if (status & USBA_END_OF_RESET) {
> - struct usba_ep *ep0;
> + struct usba_ep *ep0, *ep;
> + int i, n;
>
> usba_writel(udc, INT_CLR, USBA_END_OF_RESET);
> generate_bias_pulse(udc);
> @@ -1717,6 +1857,16 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
> if (!(usba_ep_readl(ep0, CFG) & USBA_EPT_MAPPED))
> dev_dbg(&udc->pdev->dev,
> "ODD: EP0 configuration is invalid!\n");
> +
> + /* Preallocate other endpoints */
> + n = fifo_mode ? udc->num_ep : udc->configured_ep;
> + for (i = 1; i < n; i++) {
> + ep = &udc->usba_ep[i];
> + usba_ep_writel(ep, CFG, ep->ept_cfg);
> + if (!(usba_ep_readl(ep, CFG) & USBA_EPT_MAPPED))
> + dev_dbg(&udc->pdev->dev,
> + "ODD: EP%d configuration is invalid!\n", i);

I know that it's the case for the EP0 just above and that we do it like
this in the current driver but maybe we can do more than just having a
debug message.

> + }
> }
>
> spin_unlock(&udc->lock);
> @@ -1864,6 +2014,9 @@ static int atmel_usba_stop(struct usb_gadget *gadget)
> if (gpio_is_valid(udc->vbus_pin))
> disable_irq(gpio_to_irq(udc->vbus_pin));
>
> + if (fifo_mode == 0)
> + udc->configured_ep = 1;
> +
> usba_stop(udc);
>
> udc->driver = NULL;
> @@ -1931,9 +2084,13 @@ static struct usba_ep * atmel_udc_of_init(struct platform_device *pdev,
> &flags);
> udc->vbus_pin_inverted = (flags & OF_GPIO_ACTIVE_LOW) ? 1 : 0;
>
> - pp = NULL;
> - while ((pp = of_get_next_child(np, pp)))
> - udc->num_ep++;
> + if (fifo_mode == 0) {
> + pp = NULL;
> + while ((pp = of_get_next_child(np, pp)))
> + udc->num_ep++;
> + udc->configured_ep = 1;
> + } else

Braces here

> + udc->num_ep = usba_config_fifo_table(udc);
>
> eps = devm_kzalloc(&pdev->dev, sizeof(struct usba_ep) * udc->num_ep,
> GFP_KERNEL);
> @@ -1946,7 +2103,7 @@ static struct usba_ep * atmel_udc_of_init(struct platform_device *pdev,
>
> pp = NULL;
> i = 0;
> - while ((pp = of_get_next_child(np, pp))) {
> + while ((pp = of_get_next_child(np, pp)) && i < udc->num_ep) {
> ep = &eps[i];
>
> ret = of_property_read_u32(pp, "reg", &val);
> @@ -1954,21 +2111,21 @@ static struct usba_ep * atmel_udc_of_init(struct platform_device *pdev,
> dev_err(&pdev->dev, "of_probe: reg error(%d)\n", ret);
> goto err;
> }
> - ep->index = val;
> + ep->index = fifo_mode ? udc->fifo_cfg[i].hw_ep_num : val;
>
> ret = of_property_read_u32(pp, "atmel,fifo-size", &val);
> if (ret) {
> dev_err(&pdev->dev, "of_probe: fifo-size error(%d)\n", ret);
> goto err;
> }
> - ep->fifo_size = val;
> + ep->fifo_size = fifo_mode ? udc->fifo_cfg[i].fifo_size : val;

No, this is where I would like to see that the value from the table is
still validated agains the "max value" that is stored in HW description/DT.
I know that all of our product are able to handle 1024 fifo size, but
it's more a savfe check...

>
> ret = of_property_read_u32(pp, "atmel,nb-banks", &val);
> if (ret) {
> dev_err(&pdev->dev, "of_probe: nb-banks error(%d)\n", ret);
> goto err;
> }
> - ep->nr_banks = val;
> + ep->nr_banks = fifo_mode ? udc->fifo_cfg[i].nr_banks : val;

Here however, it is pretty important to check this value. For instance,
notice that the at91sam9x5 cannot fullfil the "mode 2" configuration: we
can't silentely ignore the HW specifications given by DT.

> ep->can_dma = of_property_read_bool(pp, "atmel,can-dma");
> ep->can_isoc = of_property_read_bool(pp, "atmel,can-isoc");
> @@ -2000,6 +2157,21 @@ static struct usba_ep * atmel_udc_of_init(struct platform_device *pdev,
> ep->ep.caps.dir_in = true;
> ep->ep.caps.dir_out = true;
>
> + if (fifo_mode != 0) {
> + /*
> + * Generate ept_cfg based on FIFO size and
> + * banks number
> + */
> + if (ep->fifo_size <= 8)
> + ep->ept_cfg = USBA_BF(EPT_SIZE, USBA_EPT_SIZE_8);
> + else
> + /* LSB is bit 1, not 0 */
> + ep->ept_cfg =
> + USBA_BF(EPT_SIZE, fls(ep->fifo_size - 1) - 3);
> +
> + ep->ept_cfg |= USBA_BF(BK_NUMBER, ep->nr_banks);
> + }
> +
> if (i)
> list_add_tail(&ep->ep.ep_list, &udc->gadget.ep_list);
>
> diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.h b/drivers/usb/gadget/udc/atmel_usba_udc.h
> index b03b2eb..9551b70 100644
> --- a/drivers/usb/gadget/udc/atmel_usba_udc.h
> +++ b/drivers/usb/gadget/udc/atmel_usba_udc.h
> @@ -275,6 +275,12 @@ struct usba_dma_desc {
> u32 ctrl;
> };
>
> +struct usba_fifo_cfg {
> + u8 hw_ep_num;
> + u16 fifo_size;
> + u8 nr_banks;
> +};
> +
> struct usba_ep {
> int state;
> void __iomem *ep_regs;
> @@ -293,7 +299,7 @@ struct usba_ep {
> unsigned int can_isoc:1;
> unsigned int is_isoc:1;
> unsigned int is_in:1;
> -
> + unsigned long ept_cfg;
> #ifdef CONFIG_USB_GADGET_DEBUG_FS
> u32 last_dma_status;
> struct dentry *debugfs_dir;
> @@ -338,6 +344,8 @@ struct usba_udc {
> int vbus_pin;
> int vbus_pin_inverted;
> int num_ep;
> + int configured_ep;
> + struct usba_fifo_cfg *fifo_cfg;
> struct clk *pclk;
> struct clk *hclk;
> struct usba_ep *usba_ep;
>

Regards,
--
Nicolas Ferre

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