RE: [PATCH 05/31] usb: usbssp: Added first part of initialization sequence.

[Pawel Laszczak <pawell@cadence.com>]

Hi,
> 
> Hi,
> 
> On 19/07/18 20:57, Pawel Laszczak wrote:
> > Patch adds some initialization function. The initialization sequence
> > is quite complicated and this patch implements it only partially.
> > Initialization will be completed in next few patches.
> >
> > Patch introduce three new files:
> > 1. gadget-dbg.c - file contains functions used for debugging purpose.
> > 2. gadget-ext-caps.h - holds macro definition related to
> > 		       Extended Capabilities
> > 3. gadget-if - file implements stuff related to upper layer
> > 	(e.g usb_ep_ops, usb_gadget_ops interface).
> >
> > Signed-off-by: Pawel Laszczak <pawell@cadence.com>
> > ---
> >  drivers/usb/usbssp/Makefile          |   1 +
> >  drivers/usb/usbssp/gadget-dbg.c      |  30 ++++
> >  drivers/usb/usbssp/gadget-ext-caps.h |  53 ++++++
> >  drivers/usb/usbssp/gadget-if.c       |  24 +++
> >  drivers/usb/usbssp/gadget.c          | 242 +++++++++++++++++++++++++++
> >  drivers/usb/usbssp/gadget.h          |  15 ++
> >  6 files changed, 365 insertions(+)
> >  create mode 100644 drivers/usb/usbssp/gadget-dbg.c
> >  create mode 100644 drivers/usb/usbssp/gadget-ext-caps.h
> >  create mode 100644 drivers/usb/usbssp/gadget-if.c
> >
> > diff --git a/drivers/usb/usbssp/Makefile b/drivers/usb/usbssp/Makefile
> > index d85f15afb51c..0606f3c63cd0 100644
> > --- a/drivers/usb/usbssp/Makefile
> > +++ b/drivers/usb/usbssp/Makefile
> > @@ -5,6 +5,7 @@ CFLAGS_gadget-trace.o := -I$(src)
> >  obj-$(CONFIG_USB_USBSSP_GADGET) += usbssp.o
> >  usbssp-y 			:= usbssp-plat.o gadget-ring.o \
> >  				   gadget.o
> > +				    gadget-dbg.o
> >
> >  ifneq ($(CONFIG_TRACING),)
> >  	usbssp-y		+= gadget-trace.o
> > diff --git a/drivers/usb/usbssp/gadget-dbg.c b/drivers/usb/usbssp/gadget-dbg.c
> > new file mode 100644
> > index 000000000000..277617d1a996
> > --- /dev/null
> > +++ b/drivers/usb/usbssp/gadget-dbg.c
> > @@ -0,0 +1,30 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * USBSSP device controller driver
> > + *
> > + * Copyright (C) 2018 Cadence.
> > + *
> > + * Author: Pawel Laszczak
> > + *
> > + * A lot of code based on Linux XHCI driver.
> > + * Origin: Copyright (C) 2008 Intel Corp
> > + */
> > +
> > +#include "gadget.h"
> > +
> > +void usbssp_dbg_trace(struct usbssp_udc *usbssp_data,
> > +		      void (*trace)(struct va_format *),
> > +		      const char *fmt, ...)
> > +{
> > +	struct va_format vaf;
> > +	va_list args;
> > +
> > +	va_start(args, fmt);
> > +	vaf.fmt = fmt;
> > +	vaf.va = &args;
> > +	dev_dbg(usbssp_data->dev, "%pV\n", &vaf);
> 
> dev_dbg will mess up with timings to be useful.
> Why not just use one of the trace events you defined in gadget-trace.h?

Function is equivalent of xhci_dbg_trace from XHCI driver.
It is a function of general use. 
The problem with trace is that trace log is deleted after rebooting system. 
Using trace log is problematic during developing and debugging driver. 
Do you know whether  trace log is saved anywhere on disk ?  

> > +	trace(&vaf);
> > +	va_end(args);
> > +}
> > +EXPORT_SYMBOL_GPL(usbssp_dbg_trace);
> > +
> > diff --git a/drivers/usb/usbssp/gadget-ext-caps.h b/drivers/usb/usbssp/gadget-ext-caps.h
> > new file mode 100644
> > index 000000000000..2bf327046376
> > --- /dev/null
> > +++ b/drivers/usb/usbssp/gadget-ext-caps.h
> > @@ -0,0 +1,53 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * USBSSP device controller driver
> > + *
> > + * Copyright (C) 2018 Cadence.
> > + *
> > + * Author: Pawel Laszczak
> > + *
> > + * A lot of code based on Linux XHCI driver.
> > + * Origin: Copyright (C) 2008 Intel Corp
> > + */
> > +
> > +/* Up to 16 ms to halt an DC */
> > +#define USBSSP_MAX_HALT_USEC		(16*1000)
> > +
> > +/* DC not running - set to 1 when run/stop bit is cleared. */
> > +#define USBSSP_STS_HALT			BIT(0)
> > +
> > +/* HCCPARAMS offset from PCI base address */
> > +#define USBSSP_HCC_PARAMS_OFFSET	0x10
> > +/* HCCPARAMS contains the first extended capability pointer */
> > +#define USBSSP_HCC_EXT_CAPS(p)		(((p)>>16)&0xffff)
> > +
> > +/* Command and Status registers offset from the Operational Registers address */
> > +#define USBSSP_CMD_OFFSET		0x00
> > +#define USBSSP_STS_OFFSET		0x04
> > +
> > +/* Capability Register */
> > +/* bits 7:0 - how long is the Capabilities register */
> > +#define USBSSP_HC_LENGTH(p)		(((p)>>00)&0x00ff)
> > +
> > +/* Extended capability register fields */
> > +#define USBSSP_EXT_CAPS_ID(p)		(((p)>>0)&0xff)
> > +#define USBSSP_EXT_CAPS_NEXT(p)		(((p)>>8)&0xff)
> > +#define	v_EXT_CAPS_VAL(p)		((p)>>16)
> > +/* Extended capability IDs - ID 0 reserved */
> > +#define USBSSP_EXT_CAPS_PROTOCOL	2
> > +
> > +/* USB 2.0 hardware LMP capability*/
> > +#define USBSSP_HLC			BIT(19)
> > +#define USBSSP_BLC			BIT(20)
> > +
> > +/* command register values to disable interrupts and halt the DC */
> > +/* start/stop DC execution - do not write unless DC is halted*/
> > +#define USBSSP_CMD_RUN			BIT(0)
> > +/* Event Interrupt Enable - get irq when EINT bit is set in USBSTS register */
> > +#define USBSSP_CMD_EIE			BIT(2)
> > +/* Host System Error Interrupt Enable - get irq when HSEIE bit set in USBSTS */
> > +#define USBSSP_CMD_HSEIE		BIT(3)
> > +/* Enable Wrap Event - '1' means DC generates an event when MFINDEX wraps. */
> > +#define USBSSP_CMD_EWE			BIT(10)
> > +
> > +#define USBSSP_IRQS	(USBSSP_CMD_EIE | USBSSP_CMD_HSEIE | USBSSP_CMD_EWE)
> > diff --git a/drivers/usb/usbssp/gadget-if.c b/drivers/usb/usbssp/gadget-if.c
> > new file mode 100644
> > index 000000000000..d53e0fb65299
> > --- /dev/null
> > +++ b/drivers/usb/usbssp/gadget-if.c
> > @@ -0,0 +1,24 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * USBSSP device controller driver
> > + *
> > + * Copyright (C) 2018 Cadence.
> > + *
> > + * Author: Pawel Laszczak
> > + *
> > + */
> > +
> > +#include <linux/usb/gadget.h>
> > +#include <linux/usb/composite.h>
> > +#include "gadget.h"
> > +
> > +int usbssp_gadget_init_endpoint(struct usbssp_udc *usbssp_data)
> > +{
> > +	/*TODO: it has to be implemented*/
> > +	return 0;
> > +}
> > +
> > +void usbssp_gadget_free_endpoint(struct usbssp_udc *usbssp_data)
> > +{
> > +	/*TODO: it has to be implemented*/
> > +}
> > diff --git a/drivers/usb/usbssp/gadget.c b/drivers/usb/usbssp/gadget.c
> > index 2f60d7dd1fe4..338ec2ec18b1 100644
> > --- a/drivers/usb/usbssp/gadget.c
> > +++ b/drivers/usb/usbssp/gadget.c
> > @@ -23,6 +23,107 @@
> >  #include "gadget-trace.h"
> >  #include "gadget.h"
> >
> > +
> > +/*
> 
> /**
> 
> > + * usbssp_handshake - spin reading dc until handshake completes or fails
> > + * @ptr: address of dc register to be read
> > + * @mask: bits to look at in result of read
> > + * @done: value of those bits when handshake succeeds
> > + * @usec: timeout in microseconds
> > + *
> > + * Returns negative errno, or zero on success
> > + *
> > + * Success happens when the "mask" bits have the specified value (hardware
> > + * handshake done). There are two failure modes: "usec" have passed (major
> > + * hardware flakeout), or the register reads as all-ones (hardware removed).
> > + */
> > +int usbssp_handshake(void __iomem *ptr, u32 mask, u32 done, int usec)
> > +{
> > +	u32	result;
> > +
> > +	do {
> > +		result = readl(ptr);
> > +		if (result == ~(u32)0)	/* card removed */
> > +			return -ENODEV;
> > +		result &= mask;
> > +		if (result == done)
> > +			return 0;
> > +		udelay(1);
> > +		usec--;
> > +	} while (usec > 0);
> > +	return -ETIMEDOUT;
> > +}
> > +
> > +/*
> > + * Disable interrupts and begin the DC halting process.
> > + */
> > +void usbssp_quiesce(struct usbssp_udc *usbssp_data)
> > +{
> > +	u32 halted;
> > +	u32 cmd;
> > +	u32 mask;
> > +
> > +	mask = ~(u32)(USBSSP_IRQS);
> > +
> > +	halted = readl(&usbssp_data->op_regs->status) & STS_HALT;
> > +	if (!halted)
> > +		mask &= ~CMD_RUN;
> > +
> > +	cmd = readl(&usbssp_data->op_regs->command);
> > +	cmd &= mask;
> > +	writel(cmd, &usbssp_data->op_regs->command);
> > +}
> > +
> > +/*
> > + * Force DC into halt state.
> > + *
> > + * Disable any IRQs and clear the run/stop bit.
> > + * USBSSP will complete any current and actively pipelined transactions, and
> > + * should halt within 16 ms of the run/stop bit being cleared.
> > + * Read DC Halted bit in the status register to see when the DC is finished.
> > + */
> > +int usbssp_halt(struct usbssp_udc *usbssp_data)
> > +{
> > +	int ret;
> > +
> > +	usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_init,
> > +			"// Halt the USBSSP");
> > +	usbssp_quiesce(usbssp_data);
> > +
> > +	ret = usbssp_handshake(&usbssp_data->op_regs->status,
> > +		STS_HALT, STS_HALT, USBSSP_MAX_HALT_USEC);
> > +
> > +	if (!ret) {
> > +		dev_warn(usbssp_data->dev, "Device halt failed, %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	usbssp_data->usbssp_state |= USBSSP_STATE_HALTED;
> > +	usbssp_data->cmd_ring_state = CMD_RING_STATE_STOPPED;
> > +	return ret;
> > +}
> > +
> > +
> > +/*
> > + * Initialize memory for gadget driver and USBSSP (one-time init).
> > + *
> > + * Program the PAGESIZE register, initialize the device context array, create
> > + * device contexts, set up a command ring segment (or two?), create event
> > + * ring (one for now).
> > + */
> > +int usbssp_init(struct usbssp_udc *usbssp_data)
> > +{
> > +	int retval = 0;
> > +
> > +	spin_lock_init(&usbssp_data->lock);
> > +	spin_lock_init(&usbssp_data->irq_thread_lock);
> > +
> > +	/*TODO: memory initialization*/
> > +	//retval = usbssp_mem_init(usbssp_data, GFP_KERNEL);
> > +
> > +	return retval;
> > +}
> > +
> >  #ifdef CONFIG_PM
> >  /*
> >   * Stop DC (not bus-specific)
> > @@ -50,9 +151,146 @@ int usbssp_resume(struct usbssp_udc *usbssp_data, bool hibernated)
> >
> >  #endif	/* CONFIG_PM */
> >
> > +int usbssp_gen_setup(struct usbssp_udc *usbssp_data)
> > +{
> > +	int retval;
> > +
> > +	mutex_init(&usbssp_data->mutex);
> > +
> > +	usbssp_data->cap_regs = usbssp_data->regs;
> > +	usbssp_data->op_regs = usbssp_data->regs +
> > +		HC_LENGTH(readl(&usbssp_data->cap_regs->hc_capbase));
> > +
> > +	usbssp_data->run_regs = usbssp_data->regs +
> > +		(readl(&usbssp_data->cap_regs->run_regs_off) & RTSOFF_MASK);
> > +	/* Cache read-only capability registers */
> > +	usbssp_data->hcs_params1 = readl(&usbssp_data->cap_regs->hcs_params1);
> > +	usbssp_data->hcs_params2 = readl(&usbssp_data->cap_regs->hcs_params2);
> > +	usbssp_data->hcs_params3 = readl(&usbssp_data->cap_regs->hcs_params3);
> > +	usbssp_data->hcc_params = readl(&usbssp_data->cap_regs->hc_capbase);
> > +	usbssp_data->hci_version = HC_VERSION(usbssp_data->hcc_params);
> > +	usbssp_data->hcc_params = readl(&usbssp_data->cap_regs->hcc_params);
> > +	usbssp_data->hcc_params2 = readl(&usbssp_data->cap_regs->hcc_params2);
> > +
> > +	/* Make sure the Device Controller is halted. */
> > +	retval = usbssp_halt(usbssp_data);
> > +	if (retval)
> > +		return retval;
> > +
> > +	dev_dbg(usbssp_data->dev, "Resetting Device Controller\n");
> 
> do you really need all these dev_dbg prints? You should just fit them to one
> of the trace event classes that you already have or add a new one if needed.

They are not very useful . I deleted them.
 
> > +	/* Reset the internal DC memory state and registers. */
> > +	/*TODO: add implementation of usbssp_reset function*/
> > +	//retval = usbssp_reset(usbssp_data);
> > +	if (retval)
> > +		return retval;
> > +	dev_dbg(usbssp_data->dev, "Reset complete\n");
> > +
> > +	/* Set dma_mask and coherent_dma_mask to 64-bits,
> > +	 * if USBSSP supports 64-bit addressing
> > +	 */
> > +	if (HCC_64BIT_ADDR(usbssp_data->hcc_params) &&
> > +	    !dma_set_mask(usbssp_data->dev, DMA_BIT_MASK(64))) {
> > +		dev_dbg(usbssp_data->dev, "Enabling 64-bit DMA addresses.\n");
> > +		dma_set_coherent_mask(usbssp_data->dev, DMA_BIT_MASK(64));
> > +	} else {
> > +		/*
> > +		 * This is to avoid error in cases where a 32-bit USB
> > +		 * controller is used on a 64-bit capable system.
> > +		 */
> > +		retval = dma_set_mask(usbssp_data->dev, DMA_BIT_MASK(32));
> > +		if (retval)
> > +			return retval;
> > +		dev_dbg(usbssp_data->dev, "Enabling 32-bit DMA addresses.\n");
> > +		dma_set_coherent_mask(usbssp_data->dev, DMA_BIT_MASK(32));
> > +	}
> > +
> > +	/* Initialize USBSSP controller data structures. */
> > +	retval = usbssp_init(usbssp_data);
> > +	if (retval)
> > +		return retval;
> > +
> > +	dev_info(usbssp_data->dev, "USBSSP params 0x%08x USBSSP version 0x%x\n",
> > +		usbssp_data->hcc_params, usbssp_data->hci_version);
> > +
> > +	return 0;
> > +}
> > +
> > +/*
> > + * gadget-if.c file is part of gadget.c file and implements interface
> > + * for gadget driver
> > + */
> > +#include "gadget-if.c"
> > +
> 
> All includes should be together at the beginning of the file.

Greg Kroach-Harman wrote about including  .c files: 
"Ugh, I know USB hcd drivers love to include .c files in the middle of
them, but do we have to continue that crazy practice in newer drivers?
Is it really necessary?"

I forgot to change this, I will remove this and I will add all necessary declaration to gadget.h file.
 
> >  int usbssp_gadget_init(struct usbssp_udc *usbssp_data)
> >  {
> >  	int ret;
> > +
> > +	/*
> > +	 * Check the compiler generated sizes of structures that must be laid
> > +	 * out in specific ways for hardware access.
> > +	 */
> > +	BUILD_BUG_ON(sizeof(struct usbssp_doorbell_array) != 2*32/8);
> > +	BUILD_BUG_ON(sizeof(struct usbssp_slot_ctx) != 8*32/8);
> > +	BUILD_BUG_ON(sizeof(struct usbssp_ep_ctx) != 8*32/8);
> > +	/* usbssp_device has eight fields, and also
> > +	 * embeds one usbssp_slot_ctx and 31 usbssp_ep_ctx
> > +	 */
> > +	BUILD_BUG_ON(sizeof(struct usbssp_stream_ctx) != 4*32/8);
> > +	BUILD_BUG_ON(sizeof(union usbssp_trb) != 4*32/8);
> > +	BUILD_BUG_ON(sizeof(struct usbssp_erst_entry) != 4*32/8);
> > +	BUILD_BUG_ON(sizeof(struct usbssp_cap_regs) != 8*32/8);
> > +	BUILD_BUG_ON(sizeof(struct usbssp_intr_reg) != 8*32/8);
> > +	/* usbssp_run_regs has eight fields and embeds 128 usbssp_intr_regs */
> > +	BUILD_BUG_ON(sizeof(struct usbssp_run_regs) != (8+8*128)*32/8);
> > +
> > +	/* fill gadget fields */
> > +	/*TODO: implements usbssp_gadget_ops object*/
> > +	//usbssp_data->gadget.ops = &usbssp_gadget_ops;
> > +	usbssp_data->gadget.name = "usbssp-gadget";
> > +	usbssp_data->gadget.max_speed = USB_SPEED_SUPER_PLUS;
> > +	usbssp_data->gadget.speed = USB_SPEED_UNKNOWN;
> > +	usbssp_data->gadget.sg_supported = true;
> > +	usbssp_data->gadget.lpm_capable = 1;
> > +
> > +	usbssp_data->setup_buf = kzalloc(USBSSP_EP0_SETUP_SIZE, GFP_KERNEL);
> > +	if (!usbssp_data->setup_buf)
> > +		return -ENOMEM;
> > +
> > +	/*USBSSP support not aligned buffer but this option
> > +	 * improve performance of this controller.
> > +	 */
> 
> Multi-line comment formatting. Checkpach should complain.
It doesn't complain about this case. I don't know why.

> > +	usbssp_data->gadget.quirk_ep_out_aligned_size = true;
> > +	ret = usbssp_gen_setup(usbssp_data);
> > +	if (ret < 0) {
> > +		dev_err(usbssp_data->dev,
> > +				"Generic initialization failed with error code%d\n",
> > +				ret);
> > +		goto err3;
> > +	}
> > +
> > +	ret = usbssp_gadget_init_endpoint(usbssp_data);
> > +	if (ret < 0) {
> > +		dev_err(usbssp_data->dev, "failed to initialize endpoints\n");
> > +		goto err1;
> > +	}
> > +
> > +	ret = usb_add_gadget_udc(usbssp_data->dev, &usbssp_data->gadget);
> > +
> > +	if (ret) {
> > +		dev_err(usbssp_data->dev, "failed to register udc\n");
> > +		goto err2;
> > +	}
> > +
> > +	return ret;
> > +err2:
> > +	usbssp_gadget_free_endpoint(usbssp_data);
> > +err1:
> > +	usbssp_halt(usbssp_data);
> > +	/*TODO add implementation of usbssp_reset function*/
> > +	//usbssp_reset(usbssp_data);
> > +	/*TODO add implementation of freeing memory*/
> > +	//usbssp_mem_cleanup(usbssp_data);
> > +err3:
> >  	return ret;
> >  }
> >
> > @@ -60,5 +298,9 @@ int usbssp_gadget_exit(struct usbssp_udc *usbssp_data)
> >  {
> >  	int ret = 0;
> >
> > +	usb_del_gadget_udc(&usbssp_data->gadget);
> > +	usbssp_gadget_free_endpoint(usbssp_data);
> > +	/*TODO: add usbssp_stop implementation*/
> > +	//usbssp_stop(usbssp_data);
> >  	return ret;
> >  }
> > diff --git a/drivers/usb/usbssp/gadget.h b/drivers/usb/usbssp/gadget.h
> > index 55e20795d900..5d8918f8da84 100644
> > --- a/drivers/usb/usbssp/gadget.h
> > +++ b/drivers/usb/usbssp/gadget.h
> > @@ -12,8 +12,10 @@
> >  #ifndef __LINUX_USBSSP_GADGET_H
> >  #define __LINUX_USBSSP_GADGET_H
> >
> > +#include <linux/irq.h>
> >  #include <linux/io-64-nonatomic-lo-hi.h>
> >  #include <linux/usb/gadget.h>
> > +#include "gadget-ext-caps.h"
> >
> >  /* Max number slots - only 1 is allowed */
> >  #define DEV_MAX_SLOTS		1
> > @@ -1676,7 +1678,18 @@ static inline void usbssp_write_64(struct usbssp_udc *usbssp_data,
> >  	lo_hi_writeq(val, regs);
> >  }
> >
> > +/* USBSSP memory management */
> > +void usbssp_dbg_trace(struct usbssp_udc *usbssp_data,
> > +		void (*trace)(struct va_format *),
> > +		const char *fmt, ...);
> 
> what has this function to do with memory management?
> 
Nothing, 

> >  /* USBSSP Device controller glue */
> > +void usbssp_bottom_irq(struct work_struct *work);
> 
> usbssp_bottom_irq() wasn't defined in this patch.
Removed from this patch

> > +int usbssp_init(struct usbssp_udc *usbssp_data);
> > +void usbssp_stop(struct usbssp_udc *usbssp_data);
> > +int usbssp_handshake(void __iomem *ptr, u32 mask, u32 done, int usec);
> > +void usbssp_quiesce(struct usbssp_udc *usbssp_data);
> > +extern int usbssp_reset(struct usbssp_udc *usbssp_data);
> > +
> >  int usbssp_suspend(struct usbssp_udc *usbssp_data, bool do_wakeup);
> >  int usbssp_resume(struct usbssp_udc *usbssp_data, bool hibernated);
> >
> > @@ -1689,6 +1702,8 @@ dma_addr_t usbssp_trb_virt_to_dma(struct usbssp_segment *seg,
> >  /* USBSSP gadget interface*/
> >  int usbssp_gadget_init(struct usbssp_udc *usbssp_data);
> >  int usbssp_gadget_exit(struct usbssp_udc *usbssp_data);
> > +void usbssp_gadget_free_endpoint(struct usbssp_udc *usbssp_data);
> > +int usbssp_gadget_init_endpoint(struct usbssp_udc *usbssp_data);
> >
> >  static inline char *usbssp_slot_state_string(u32 state)
> >  {
> >
> 
> --
> cheers,
> -roger
> 
> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

thanks
cheers,
Pawel