isp1301_omap.c

底层驱动开发

	/* implicit lock:  we're the only task using this device */
	isp->working = 1;
	do {
		stop = test_bit(WORK_STOP, &isp->todo);

#ifdef	CONFIG_USB_OTG
		/* transfer state from otg engine to isp1301 */
		if (test_and_clear_bit(WORK_UPDATE_ISP, &isp->todo)) {
			otg_update_isp(isp);
			put_device(&isp->client.dev);
		}
#endif
		/* transfer state from isp1301 to otg engine */
		if (test_and_clear_bit(WORK_UPDATE_OTG, &isp->todo)) {
			u8		stat = isp1301_clear_latch(isp);

			isp_update_otg(isp, stat);
			put_device(&isp->client.dev);
		}

		if (test_and_clear_bit(WORK_HOST_RESUME, &isp->todo)) {
			u32	otg_ctrl;

			/*
			 * skip A_WAIT_VRISE; hc transitions invisibly
			 * skip A_WAIT_BCON; same.
			 */
			switch (isp->otg.state) {
			case OTG_STATE_A_WAIT_BCON:
			case OTG_STATE_A_WAIT_VRISE:
				isp->otg.state = OTG_STATE_A_HOST;
				pr_debug("  --> a_host\n");
				otg_ctrl = OTG_CTRL_REG;
				otg_ctrl |= OTG_A_BUSREQ;
				otg_ctrl &= ~(OTG_BUSDROP|OTG_B_BUSREQ)
						& OTG_CTRL_MASK;
				OTG_CTRL_REG = otg_ctrl;
				break;
			case OTG_STATE_B_WAIT_ACON:
				isp->otg.state = OTG_STATE_B_HOST;
				pr_debug("  --> b_host (acon)\n");
				break;
			case OTG_STATE_B_HOST:
			case OTG_STATE_B_IDLE:
			case OTG_STATE_A_IDLE:
				break;
			default:
				pr_debug("  host resume in %s\n",
						state_name(isp));
			}
			host_resume(isp);
			// mdelay(10);
			put_device(&isp->client.dev);
		}

		if (test_and_clear_bit(WORK_TIMER, &isp->todo)) {
#ifdef	VERBOSE
			dump_regs(isp, "timer");
			if (!stop)
				mod_timer(&isp->timer, jiffies + TIMER_JIFFIES);
#endif
			put_device(&isp->client.dev);
		}

		if (isp->todo)
			dev_vdbg(&isp->client.dev,
				"work done, todo = 0x%lx\n",
				isp->todo);
		if (stop) {
			dev_dbg(&isp->client.dev, "stop\n");
			break;
		}
	} while (isp->todo);
	isp->working = 0;
}

static irqreturn_t isp1301_irq(int irq, void *isp, struct pt_regs *regs)
{
	isp1301_defer_work(isp, WORK_UPDATE_OTG);
	return IRQ_HANDLED;
}

static void isp1301_timer(unsigned long _isp)
{
	isp1301_defer_work((void *)_isp, WORK_TIMER);
}

/*-------------------------------------------------------------------------*/

static void isp1301_release(struct device *dev)
{
	struct isp1301	*isp;

	isp = container_of(dev, struct isp1301, client.dev);

	/* ugly -- i2c hijacks our memory hook to wait_for_completion() */
	if (isp->i2c_release)
		isp->i2c_release(dev);
	kfree (isp);
}

static struct isp1301 *the_transceiver;

static int isp1301_detach_client(struct i2c_client *i2c)
{
	struct isp1301	*isp;

	isp = container_of(i2c, struct isp1301, client);

	isp1301_clear_bits(isp, ISP1301_INTERRUPT_FALLING, ~0);
	isp1301_clear_bits(isp, ISP1301_INTERRUPT_RISING, ~0);
	free_irq(isp->irq, isp);
#ifdef	CONFIG_USB_OTG
	otg_unbind(isp);
#endif
	if (machine_is_omap_h2())
		omap_free_gpio(2);

	isp->timer.data = 0;
	set_bit(WORK_STOP, &isp->todo);
	del_timer_sync(&isp->timer);
	flush_scheduled_work();

	put_device(&i2c->dev);
	the_transceiver = 0;

	return i2c_detach_client(i2c);
}

/*-------------------------------------------------------------------------*/

/* NOTE:  three modes are possible here, only one of which
 * will be standards-conformant on any given system:
 *
 *  - OTG mode (dual-role), required if there's a Mini-AB connector
 *  - HOST mode, for when there's one or more A (host) connectors
 *  - DEVICE mode, for when there's a B/Mini-B (device) connector
 *
 * As a rule, you won't have an isp1301 chip unless it's there to
 * support the OTG mode.  Other modes help testing USB controllers 
 * in isolation from (full) OTG support, or maybe so later board
 * revisions can help to support those feature.
 */

#ifdef	CONFIG_USB_OTG

static int isp1301_otg_enable(struct isp1301 *isp)
{
	power_up(isp);
	otg_init(isp);

	/* NOTE:  since we don't change this, this provides
	 * a few more interrupts than are strictly needed.
	 */
	isp1301_set_bits(isp, ISP1301_INTERRUPT_RISING,
	 	INTR_VBUS_VLD | INTR_SESS_VLD | INTR_ID_GND);
	isp1301_set_bits(isp, ISP1301_INTERRUPT_FALLING,
	 	INTR_VBUS_VLD | INTR_SESS_VLD | INTR_ID_GND);

	dev_info(&isp->client.dev, "ready for dual-role USB ...\n");

	return 0;
}

#endif

/* add or disable the host device+driver */
static int
isp1301_set_host(struct otg_transceiver *otg, struct usb_bus *host)
{
	struct isp1301	*isp = container_of(otg, struct isp1301, otg);

	if (!otg || isp != the_transceiver)
		return -ENODEV;

	if (!host) {
		OTG_IRQ_EN_REG = 0;
		power_down(isp);
		isp->otg.host = 0;
		return 0;
	}

#ifdef	CONFIG_USB_OTG
	isp->otg.host = host;
	dev_dbg(&isp->client.dev, "registered host\n");
	host_suspend(isp);
	if (isp->otg.gadget)
		return isp1301_otg_enable(isp);
	return 0;

#elif	!defined(CONFIG_USB_GADGET_OMAP)
	// FIXME update its refcount
	isp->otg.host = host;

	power_up(isp);

	if (machine_is_omap_h2())
		isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1, MC1_DAT_SE0);

	dev_info(&isp->client.dev, "A-Host sessions ok\n");
	isp1301_set_bits(isp, ISP1301_INTERRUPT_RISING,
	 	INTR_ID_GND);
	isp1301_set_bits(isp, ISP1301_INTERRUPT_FALLING,
	 	INTR_ID_GND);

	/* If this has a Mini-AB connector, this mode is highly
	 * nonstandard ... but can be handy for testing, especially with
	 * the Mini-A end of an OTG cable.  (Or something nonstandard
	 * like MiniB-to-StandardB, maybe built with a gender mender.)
	 */
	isp1301_set_bits(isp, ISP1301_OTG_CONTROL_1, OTG1_VBUS_DRV);

	dump_regs(isp, __FUNCTION__);

	return 0;

#else
	dev_dbg(&isp->client.dev, "host sessions not allowed\n");
	return -EINVAL;
#endif

}

static int
isp1301_set_peripheral(struct otg_transceiver *otg, struct usb_gadget *gadget)
{
	struct isp1301	*isp = container_of(otg, struct isp1301, otg);

	if (!otg || isp != the_transceiver)
		return -ENODEV;

	if (!gadget) {
		OTG_IRQ_EN_REG = 0;
		if (!isp->otg.default_a)
			enable_vbus_draw(isp, 0);
		usb_gadget_vbus_disconnect(isp->otg.gadget);
		isp->otg.gadget = 0;
		power_down(isp);
		return 0;
	}

#ifdef	CONFIG_USB_OTG
	isp->otg.gadget = gadget;
	dev_dbg(&isp->client.dev, "registered gadget\n");
	/* gadget driver may be suspended until vbus_connect () */
	if (isp->otg.host)
		return isp1301_otg_enable(isp);
	return 0;

#elif	!defined(CONFIG_USB_OHCI_HCD) && !defined(CONFIG_USB_OHCI_HCD_MODULE)
	isp->otg.gadget = gadget;
	// FIXME update its refcount

	OTG_CTRL_REG = (OTG_CTRL_REG & OTG_CTRL_MASK
				& ~(OTG_XCEIV_OUTPUTS|OTG_CTRL_BITS))
			| OTG_ID;
	power_up(isp);
	isp->otg.state = OTG_STATE_B_IDLE;

	if (machine_is_omap_h2())
		isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1, MC1_DAT_SE0);

	isp1301_set_bits(isp, ISP1301_INTERRUPT_RISING,
	 	INTR_SESS_VLD);
	isp1301_set_bits(isp, ISP1301_INTERRUPT_FALLING,
	 	INTR_VBUS_VLD);
	dev_info(&isp->client.dev, "B-Peripheral sessions ok\n");
	dump_regs(isp, __FUNCTION__);

	/* If this has a Mini-AB connector, this mode is highly
	 * nonstandard ... but can be handy for testing, so long
	 * as you don't plug a Mini-A cable into the jack.
	 */
	if (isp1301_get_u8(isp, ISP1301_INTERRUPT_SOURCE) & INTR_VBUS_VLD)
		b_peripheral(isp);

	return 0;

#else
	dev_dbg(&isp->client.dev, "peripheral sessions not allowed\n");
	return -EINVAL;
#endif
}


/*-------------------------------------------------------------------------*/

static int
isp1301_set_power(struct otg_transceiver *dev, unsigned mA)
{
	if (!the_transceiver)
		return -ENODEV;
	if (dev->state == OTG_STATE_B_PERIPHERAL)
		enable_vbus_draw(the_transceiver, mA);
	return 0;
}

static int
isp1301_start_srp(struct otg_transceiver *dev)
{
	struct isp1301	*isp = container_of(dev, struct isp1301, otg);
	u32		otg_ctrl;

	if (!dev || isp != the_transceiver
			|| isp->otg.state != OTG_STATE_B_IDLE)
		return -ENODEV;

	otg_ctrl = OTG_CTRL_REG;
	if (!(otg_ctrl & OTG_BSESSEND))
		return -EINVAL;

	otg_ctrl |= OTG_B_BUSREQ;
	otg_ctrl &= ~OTG_A_BUSREQ & OTG_CTRL_MASK;
	OTG_CTRL_REG = otg_ctrl;
	isp->otg.state = OTG_STATE_B_SRP_INIT;

	pr_debug("otg: SRP, %s ... %06x\n", state_name(isp), OTG_CTRL_REG);
#ifdef	CONFIG_USB_OTG
	check_state(isp, __FUNCTION__);
#endif
	return 0;
}

static int
isp1301_start_hnp(struct otg_transceiver *dev)
{
#ifdef	CONFIG_USB_OTG
	struct isp1301	*isp = container_of(dev, struct isp1301, otg);

	if (!dev || isp != the_transceiver)
		return -ENODEV;
	if (isp->otg.default_a && (isp->otg.host == NULL
			|| !isp->otg.host->b_hnp_enable))
		return -ENOTCONN;
	if (!isp->otg.default_a && (isp->otg.gadget == NULL
			|| !isp->otg.gadget->b_hnp_enable))
		return -ENOTCONN;

	/* We want hardware to manage most HNP protocol timings.
	 * So do this part as early as possible...
	 */
	switch (isp->otg.state) {
	case OTG_STATE_B_HOST:
		isp->otg.state = OTG_STATE_B_PERIPHERAL;
		/* caller will suspend next */
		break;
	case OTG_STATE_A_HOST:
#if 0
		/* autoconnect mode avoids irq latency bugs */
		isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1,
				MC1_BDIS_ACON_EN);
#endif
		/* caller must suspend then clear A_BUSREQ */
		usb_gadget_vbus_connect(isp->otg.gadget);
		OTG_CTRL_REG |= OTG_A_SETB_HNPEN;

		break;
	case OTG_STATE_A_PERIPHERAL:
		/* initiated by B-Host suspend */
		break;
	default:
		return -EILSEQ;
	}
	pr_debug("otg: HNP %s, %06x ...\n",
		state_name(isp), OTG_CTRL_REG);
	check_state(isp, __FUNCTION__);
	return 0;
#else
	/* srp-only */
	return -EINVAL;
#endif
}

/*-------------------------------------------------------------------------*/

/* no error returns, they'd just make bus scanning stop */
static int isp1301_probe(struct i2c_adapter *bus, int address, int kind)
{
	int			status;
	struct isp1301		*isp;
	struct i2c_client	*i2c;

	if (the_transceiver)
		return 0;

	isp = kzalloc(sizeof *isp, GFP_KERNEL);
	if (!isp)
		return 0;

	INIT_WORK(&isp->work, isp1301_work, isp);
	init_timer(&isp->timer);
	isp->timer.function = isp1301_timer;
	isp->timer.data = (unsigned long) isp;

	isp->irq = -1;
	isp->client.addr = address;
	i2c_set_clientdata(&isp->client, isp);
	isp->client.adapter = bus;
	isp->client.driver = &isp1301_driver;
	strlcpy(isp->client.name, DRIVER_NAME, I2C_NAME_SIZE);
	i2c = &isp->client;

	/* if this is a true probe, verify the chip ... */
	if (kind < 0) {
		status = isp1301_get_u16(isp, ISP1301_VENDOR_ID);
		if (status != I2C_VENDOR_ID_PHILIPS) {
			dev_dbg(&bus->dev, "addr %d not philips id: %d\n",
				address, status);
			goto fail1;
		}
		status = isp1301_get_u16(isp, ISP1301_PRODUCT_ID);
		if (status != I2C_PRODUCT_ID_PHILIPS_1301) {
			dev_dbg(&bus->dev, "%d not isp1301, %d\n",
				address, status);
			goto fail1;
		}
	}

	status = i2c_attach_client(i2c);
	if (status < 0) {
		dev_dbg(&bus->dev, "can't attach %s to device %d, err %d\n",
				DRIVER_NAME, address, status);
fail1:
		kfree(isp);
		return 0;
	}
	isp->i2c_release = i2c->dev.release;
	i2c->dev.release = isp1301_release;

	/* initial development used chiprev 2.00 */
	status = i2c_smbus_read_word_data(i2c, ISP1301_BCD_DEVICE);
	dev_info(&i2c->dev, "chiprev %x.%02x, driver " DRIVER_VERSION "\n",
		status >> 8, status & 0xff);

	/* make like power-on reset */
	isp1301_clear_bits(isp, ISP1301_MODE_CONTROL_1, MC1_MASK);

	isp1301_set_bits(isp, ISP1301_MODE_CONTROL_2, MC2_BI_DI);
	isp1301_clear_bits(isp, ISP1301_MODE_CONTROL_2, ~MC2_BI_DI);

	isp1301_set_bits(isp, ISP1301_OTG_CONTROL_1,
				OTG1_DM_PULLDOWN | OTG1_DP_PULLDOWN);
	isp1301_clear_bits(isp, ISP1301_OTG_CONTROL_1,
				~(OTG1_DM_PULLDOWN | OTG1_DP_PULLDOWN));

	isp1301_clear_bits(isp, ISP1301_INTERRUPT_LATCH, ~0);
	isp1301_clear_bits(isp, ISP1301_INTERRUPT_FALLING, ~0);
	isp1301_clear_bits(isp, ISP1301_INTERRUPT_RISING, ~0);

#ifdef	CONFIG_USB_OTG
	status = otg_bind(isp);
	if (status < 0) {
		dev_dbg(&i2c->dev, "can't bind OTG\n");
		goto fail2;
	}
#endif

	if (machine_is_omap_h2()) {
		/* full speed signaling by default */
		isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1,
			MC1_SPEED_REG);
		isp1301_set_bits(isp, ISP1301_MODE_CONTROL_2,
			MC2_SPD_SUSP_CTRL);

		/* IRQ wired at M14 */
		omap_cfg_reg(M14_1510_GPIO2);
		isp->irq = OMAP_GPIO_IRQ(2);
		omap_request_gpio(2);
		omap_set_gpio_direction(2, 1);
		omap_set_gpio_edge_ctrl(2, OMAP_GPIO_FALLING_EDGE);
	}

	status = request_irq(isp->irq, isp1301_irq,
			SA_SAMPLE_RANDOM, DRIVER_NAME, isp);
	if (status < 0) {
		dev_dbg(&i2c->dev, "can't get IRQ %d, err %d\n",
				isp->irq, status);
#ifdef	CONFIG_USB_OTG
fail2:
#endif
		i2c_detach_client(i2c);
		goto fail1;
	}

	isp->otg.dev = &isp->client.dev;
	isp->otg.label = DRIVER_NAME;

	isp->otg.set_host = isp1301_set_host,
	isp->otg.set_peripheral = isp1301_set_peripheral,
	isp->otg.set_power = isp1301_set_power,
	isp->otg.start_srp = isp1301_start_srp,
	isp->otg.start_hnp = isp1301_start_hnp,

	enable_vbus_draw(isp, 0);
	power_down(isp);
	the_transceiver = isp;

#ifdef	CONFIG_USB_OTG
	update_otg1(isp, isp1301_get_u8(isp, ISP1301_INTERRUPT_SOURCE));
	update_otg2(isp, isp1301_get_u8(isp, ISP1301_OTG_STATUS));
#endif

	dump_regs(isp, __FUNCTION__);

#ifdef	VERBOSE
	mod_timer(&isp->timer, jiffies + TIMER_JIFFIES);
	dev_dbg(&i2c->dev, "scheduled timer, %d min\n", TIMER_MINUTES);
#endif

	status = otg_set_transceiver(&isp->otg);
	if (status < 0)
		dev_err(&i2c->dev, "can't register transceiver, %d\n",
			status);

	return 0;
}

static int isp1301_scan_bus(struct i2c_adapter *bus)
{
	if (!i2c_check_functionality(bus, I2C_FUNC_SMBUS_BYTE_DATA
			| I2C_FUNC_SMBUS_READ_WORD_DATA))
		return -EINVAL;
	return i2c_probe(bus, &addr_data, isp1301_probe);
}

static struct i2c_driver isp1301_driver = {
	.owner		= THIS_MODULE,
	.name		= "isp1301_omap",
	.id		= 1301,		/* FIXME "official", i2c-ids.h */
	.class		= I2C_CLASS_HWMON,
	.flags		= I2C_DF_NOTIFY,
	.attach_adapter	= isp1301_scan_bus,
	.detach_client	= isp1301_detach_client,
};

/*-------------------------------------------------------------------------*/

static int __init isp_init(void)
{
	return i2c_add_driver(&isp1301_driver);
}
module_init(isp_init);

static void __exit isp_exit(void)
{
	if (the_transceiver)
		otg_set_transceiver(0);
	i2c_del_driver(&isp1301_driver);
}
module_exit(isp_exit);